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linux/include/net/nexthop.h

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net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: add support for notifiers This patch adds nexthop add/del notifiers. To be used by vxlan driver in a later patch. Could possibly be used by switchdev drivers in the future. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:15 -07:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add support for IPv6 gateways Handle IPv6 gateway in a nexthop spec. If nh_family is set to AF_INET6, NHA_GATEWAY is expected to be an IPv6 address. Add ipv6 option to gw in nh_config to hold the address, add fib6_nh to nh_info to leverage the ipv6 initialization and cleanup code. Update nh_fill_node to dump the v6 address. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:06 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: support for fdb ecmp nexthops This patch introduces ecmp nexthops and nexthop groups for mac fdb entries. In subsequent patches this is used by the vxlan driver fdb entries. The use case is E-VPN multihoming [1,2,3] which requires bridged vxlan traffic to be load balanced to remote switches (vteps) belonging to the same multi-homed ethernet segment (This is analogous to a multi-homed LAG but over vxlan). Changes include new nexthop flag NHA_FDB for nexthops referenced by fdb entries. These nexthops only have ip. This patch includes appropriate checks to avoid routes referencing such nexthops. example: $ip nexthop add id 12 via 172.16.1.2 fdb $ip nexthop add id 13 via 172.16.1.3 fdb $ip nexthop add id 102 group 12/13 fdb $bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self [1] E-VPN https://tools.ietf.org/html/rfc7432 [2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365 [3] LPC talk with mention of nexthop groups for L2 ecmp http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf v4 - fixed uninitialized variable reported by kernel test robot Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:13 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add support for IPv4 nexthops Add support for IPv4 nexthops. If nh_family is set to AF_INET, then NHA_GATEWAY is expected to be an IPv4 address. Register for netdev events to be notified of admin up/down changes as well as deletes. A hash table is used to track nexthop per devices to quickly convert device events to the affected nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:05 -07:00
nexthop: Add support for IPv6 gateways Handle IPv6 gateway in a nexthop spec. If nh_family is set to AF_INET6, NHA_GATEWAY is expected to be an IPv6 address. Add ipv6 option to gw in nh_config to hold the address, add fib6_nh to nh_info to leverage the ipv6 initialization and cleanup code. Update nh_fill_node to dump the v6 address. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:06 -07:00
nexthop: Add support for IPv4 nexthops Add support for IPv4 nexthops. If nh_family is set to AF_INET, then NHA_GATEWAY is expected to be an IPv4 address. Register for netdev events to be notified of admin up/down changes as well as deletes. A hash table is used to track nexthop per devices to quickly convert device events to the affected nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:05 -07:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add implementation of resilient next-hop groups At this moment, there is only one type of next-hop group: an mpath group, which implements the hash-threshold algorithm. To select a next hop, hash-threshold algorithm first assigns a range of hashes to each next hop in the group, and then selects the next hop by comparing the SKB hash with the individual ranges. When a next hop is removed from the group, the ranges are recomputed, which leads to reassignment of parts of hash space from one next hop to another. While there will usually be some overlap between the previous and the new distribution, some traffic flows change the next hop that they resolve to. That causes problems e.g. as established TCP connections are reset, because the traffic is forwarded to a server that is not familiar with the connection. Resilient hashing is a technique to address the above problem. Resilient next-hop group has another layer of indirection between the group itself and its constituent next hops: a hash table. The selection algorithm uses a straightforward modulo operation to choose a hash bucket, and then reads the next hop that this bucket contains, and forwards traffic there. This indirection brings an important feature. In the hash-threshold algorithm, the range of hashes associated with a next hop must be continuous. With a hash table, mapping between the hash table buckets and the individual next hops is arbitrary. Therefore when a next hop is deleted the buckets that held it are simply reassigned to other next hops. When weights of next hops in a group are altered, it may be possible to choose a subset of buckets that are currently not used for forwarding traffic, and use those to satisfy the new next-hop distribution demands, keeping the "busy" buckets intact. This way, established flows are ideally kept being forwarded to the same endpoints through the same paths as before the next-hop group change. In a nutshell, the algorithm works as follows. Each next hop has a number of buckets that it wants to have, according to its weight and the number of buckets in the hash table. In case of an event that might cause bucket allocation change, the numbers for individual next hops are updated, similarly to how ranges are updated for mpath group next hops. Following that, a new "upkeep" algorithm runs, and for idle buckets that belong to a next hop that is currently occupying more buckets than it wants (it is "overweight"), it migrates the buckets to one of the next hops that has fewer buckets than it wants (it is "underweight"). If, after this, there are still underweight next hops, another upkeep run is scheduled to a future time. Chances are there are not enough "idle" buckets to satisfy the new demands. The algorithm has knobs to select both what it means for a bucket to be idle, and for whether and when to forcefully migrate buckets if there keeps being an insufficient number of idle buckets. There are three users of the resilient data structures. - The forwarding code accesses them under RCU, and does not modify them except for updating the time a selected bucket was last used. - Netlink code, running under RTNL, which may modify the data. - The delayed upkeep code, which may modify the data. This runs unlocked, and mutual exclusion between the RTNL code and the delayed upkeep is maintained by canceling the delayed work synchronously before the RTNL code touches anything. Later it restarts the delayed work if necessary. The RTNL code has to implement next-hop group replacement, next hop removal, etc. For removal, the mpath code uses a neat trick of having a backup next hop group structure, doing the necessary changes offline, and then RCU-swapping them in. However, the hash tables for resilient hashing are about an order of magnitude larger than the groups themselves (the size might be e.g. 4K entries), and it was felt that keeping two of them is an overkill. Both the primary next-hop group and the spare therefore use the same resilient table, and writers are careful to keep all references valid for the forwarding code. The hash table references next-hop group entries from the next-hop group that is currently in the primary role (i.e. not spare). During the transition from primary to spare, the table references a mix of both the primary group and the spare. When a next hop is deleted, the corresponding buckets are not set to NULL, but instead marked as empty, so that the pointer is valid and can be used by the forwarding code. The buckets are then migrated to a new next-hop group entry during upkeep. The only times that the hash table is invalid is the very beginning and very end of its lifetime. Between those points, it is always kept valid. This patch introduces the core support code itself. It does not handle notifications towards drivers, which are kept as if the group were an mpath one. It does not handle netlink either. The only bit currently exposed to user space is the new next-hop group type, and that is currently bounced. There is therefore no way to actually access this code. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:16 +01:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add support for lwt encaps Add support for NHA_ENCAP and NHA_ENCAP_TYPE. Leverages the existing code for lwtunnel within fib_nh_common, so the only change needed is handling the attributes in the nexthop code. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:07 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: support for fdb ecmp nexthops This patch introduces ecmp nexthops and nexthop groups for mac fdb entries. In subsequent patches this is used by the vxlan driver fdb entries. The use case is E-VPN multihoming [1,2,3] which requires bridged vxlan traffic to be load balanced to remote switches (vteps) belonging to the same multi-homed ethernet segment (This is analogous to a multi-homed LAG but over vxlan). Changes include new nexthop flag NHA_FDB for nexthops referenced by fdb entries. These nexthops only have ip. This patch includes appropriate checks to avoid routes referencing such nexthops. example: $ip nexthop add id 12 via 172.16.1.2 fdb $ip nexthop add id 13 via 172.16.1.3 fdb $ip nexthop add id 102 group 12/13 fdb $bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self [1] E-VPN https://tools.ietf.org/html/rfc7432 [2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365 [3] LPC talk with mention of nexthop groups for L2 ecmp http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf v4 - fixed uninitialized variable reported by kernel test robot Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:13 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add support for IPv4 nexthops Add support for IPv4 nexthops. If nh_family is set to AF_INET, then NHA_GATEWAY is expected to be an IPv4 address. Register for netdev events to be notified of admin up/down changes as well as deletes. A hash table is used to track nexthop per devices to quickly convert device events to the affected nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:05 -07:00
nexthop: Add support for IPv6 gateways Handle IPv6 gateway in a nexthop spec. If nh_family is set to AF_INET6, NHA_GATEWAY is expected to be an IPv6 address. Add ipv6 option to gw in nh_config to hold the address, add fib6_nh to nh_info to leverage the ipv6 initialization and cleanup code. Update nh_fill_node to dump the v6 address. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:06 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add implementation of resilient next-hop groups At this moment, there is only one type of next-hop group: an mpath group, which implements the hash-threshold algorithm. To select a next hop, hash-threshold algorithm first assigns a range of hashes to each next hop in the group, and then selects the next hop by comparing the SKB hash with the individual ranges. When a next hop is removed from the group, the ranges are recomputed, which leads to reassignment of parts of hash space from one next hop to another. While there will usually be some overlap between the previous and the new distribution, some traffic flows change the next hop that they resolve to. That causes problems e.g. as established TCP connections are reset, because the traffic is forwarded to a server that is not familiar with the connection. Resilient hashing is a technique to address the above problem. Resilient next-hop group has another layer of indirection between the group itself and its constituent next hops: a hash table. The selection algorithm uses a straightforward modulo operation to choose a hash bucket, and then reads the next hop that this bucket contains, and forwards traffic there. This indirection brings an important feature. In the hash-threshold algorithm, the range of hashes associated with a next hop must be continuous. With a hash table, mapping between the hash table buckets and the individual next hops is arbitrary. Therefore when a next hop is deleted the buckets that held it are simply reassigned to other next hops. When weights of next hops in a group are altered, it may be possible to choose a subset of buckets that are currently not used for forwarding traffic, and use those to satisfy the new next-hop distribution demands, keeping the "busy" buckets intact. This way, established flows are ideally kept being forwarded to the same endpoints through the same paths as before the next-hop group change. In a nutshell, the algorithm works as follows. Each next hop has a number of buckets that it wants to have, according to its weight and the number of buckets in the hash table. In case of an event that might cause bucket allocation change, the numbers for individual next hops are updated, similarly to how ranges are updated for mpath group next hops. Following that, a new "upkeep" algorithm runs, and for idle buckets that belong to a next hop that is currently occupying more buckets than it wants (it is "overweight"), it migrates the buckets to one of the next hops that has fewer buckets than it wants (it is "underweight"). If, after this, there are still underweight next hops, another upkeep run is scheduled to a future time. Chances are there are not enough "idle" buckets to satisfy the new demands. The algorithm has knobs to select both what it means for a bucket to be idle, and for whether and when to forcefully migrate buckets if there keeps being an insufficient number of idle buckets. There are three users of the resilient data structures. - The forwarding code accesses them under RCU, and does not modify them except for updating the time a selected bucket was last used. - Netlink code, running under RTNL, which may modify the data. - The delayed upkeep code, which may modify the data. This runs unlocked, and mutual exclusion between the RTNL code and the delayed upkeep is maintained by canceling the delayed work synchronously before the RTNL code touches anything. Later it restarts the delayed work if necessary. The RTNL code has to implement next-hop group replacement, next hop removal, etc. For removal, the mpath code uses a neat trick of having a backup next hop group structure, doing the necessary changes offline, and then RCU-swapping them in. However, the hash tables for resilient hashing are about an order of magnitude larger than the groups themselves (the size might be e.g. 4K entries), and it was felt that keeping two of them is an overkill. Both the primary next-hop group and the spare therefore use the same resilient table, and writers are careful to keep all references valid for the forwarding code. The hash table references next-hop group entries from the next-hop group that is currently in the primary role (i.e. not spare). During the transition from primary to spare, the table references a mix of both the primary group and the spare. When a next hop is deleted, the corresponding buckets are not set to NULL, but instead marked as empty, so that the pointer is valid and can be used by the forwarding code. The buckets are then migrated to a new next-hop group entry during upkeep. The only times that the hash table is invalid is the very beginning and very end of its lifetime. Between those points, it is always kept valid. This patch introduces the core support code itself. It does not handle notifications towards drivers, which are kept as if the group were an mpath one. It does not handle netlink either. The only bit currently exposed to user space is the new next-hop group type, and that is currently bounced. There is therefore no way to actually access this code. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:16 +01:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Introduce to struct nh_grp_entry a per-type union The values that a next-hop group needs to keep track of depend on the group type. Introduce a union to separate fields specific to the mpath groups from fields specific to other group types. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 13:49:15 +01:00
nexthop: Rename artifacts related to legacy multipath nexthop groups After resilient next-hop groups have been added recently, there are two types of multipath next-hop groups: the legacy "mpath", and the new "resilient". Calling the legacy next-hop group type "mpath" is unfortunate, because that describes the fact that a packet could be forwarded in one of several paths, which is also true for the resilient next-hop groups. Therefore, to make the naming clearer, rename various artifacts to reflect the assumptions made. Therefore as of this patch: - The flag for multipath groups is nh_grp_entry::is_multipath. This includes the legacy and resilient groups, as well as any future group types that behave as multipath groups. Functions that assume this have "mpath" in the name. - The flag for legacy multipath groups is nh_grp_entry::hash_threshold. Functions that assume this have "hthr" in the name. - The flag for resilient groups is nh_grp_entry::resilient. Functions that assume this have "res" in the name. Besides the above, struct nh_grp_entry::mpath was renamed to ::hthr as well. UAPI artifacts were obviously left intact. Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-26 14:20:22 +01:00
nexthop: Add implementation of resilient next-hop groups At this moment, there is only one type of next-hop group: an mpath group, which implements the hash-threshold algorithm. To select a next hop, hash-threshold algorithm first assigns a range of hashes to each next hop in the group, and then selects the next hop by comparing the SKB hash with the individual ranges. When a next hop is removed from the group, the ranges are recomputed, which leads to reassignment of parts of hash space from one next hop to another. While there will usually be some overlap between the previous and the new distribution, some traffic flows change the next hop that they resolve to. That causes problems e.g. as established TCP connections are reset, because the traffic is forwarded to a server that is not familiar with the connection. Resilient hashing is a technique to address the above problem. Resilient next-hop group has another layer of indirection between the group itself and its constituent next hops: a hash table. The selection algorithm uses a straightforward modulo operation to choose a hash bucket, and then reads the next hop that this bucket contains, and forwards traffic there. This indirection brings an important feature. In the hash-threshold algorithm, the range of hashes associated with a next hop must be continuous. With a hash table, mapping between the hash table buckets and the individual next hops is arbitrary. Therefore when a next hop is deleted the buckets that held it are simply reassigned to other next hops. When weights of next hops in a group are altered, it may be possible to choose a subset of buckets that are currently not used for forwarding traffic, and use those to satisfy the new next-hop distribution demands, keeping the "busy" buckets intact. This way, established flows are ideally kept being forwarded to the same endpoints through the same paths as before the next-hop group change. In a nutshell, the algorithm works as follows. Each next hop has a number of buckets that it wants to have, according to its weight and the number of buckets in the hash table. In case of an event that might cause bucket allocation change, the numbers for individual next hops are updated, similarly to how ranges are updated for mpath group next hops. Following that, a new "upkeep" algorithm runs, and for idle buckets that belong to a next hop that is currently occupying more buckets than it wants (it is "overweight"), it migrates the buckets to one of the next hops that has fewer buckets than it wants (it is "underweight"). If, after this, there are still underweight next hops, another upkeep run is scheduled to a future time. Chances are there are not enough "idle" buckets to satisfy the new demands. The algorithm has knobs to select both what it means for a bucket to be idle, and for whether and when to forcefully migrate buckets if there keeps being an insufficient number of idle buckets. There are three users of the resilient data structures. - The forwarding code accesses them under RCU, and does not modify them except for updating the time a selected bucket was last used. - Netlink code, running under RTNL, which may modify the data. - The delayed upkeep code, which may modify the data. This runs unlocked, and mutual exclusion between the RTNL code and the delayed upkeep is maintained by canceling the delayed work synchronously before the RTNL code touches anything. Later it restarts the delayed work if necessary. The RTNL code has to implement next-hop group replacement, next hop removal, etc. For removal, the mpath code uses a neat trick of having a backup next hop group structure, doing the necessary changes offline, and then RCU-swapping them in. However, the hash tables for resilient hashing are about an order of magnitude larger than the groups themselves (the size might be e.g. 4K entries), and it was felt that keeping two of them is an overkill. Both the primary next-hop group and the spare therefore use the same resilient table, and writers are careful to keep all references valid for the forwarding code. The hash table references next-hop group entries from the next-hop group that is currently in the primary role (i.e. not spare). During the transition from primary to spare, the table references a mix of both the primary group and the spare. When a next hop is deleted, the corresponding buckets are not set to NULL, but instead marked as empty, so that the pointer is valid and can be used by the forwarding code. The buckets are then migrated to a new next-hop group entry during upkeep. The only times that the hash table is invalid is the very beginning and very end of its lifetime. Between those points, it is always kept valid. This patch introduces the core support code itself. It does not handle notifications towards drivers, which are kept as if the group were an mpath one. It does not handle netlink either. The only bit currently exposed to user space is the new next-hop group type, and that is currently bounced. There is therefore no way to actually access this code. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:16 +01:00
nexthop: Introduce to struct nh_grp_entry a per-type union The values that a next-hop group needs to keep track of depend on the group type. Introduce a union to separate fields specific to the mpath groups from fields specific to other group types. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 13:49:15 +01:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthops: don't modify published nexthop groups We must avoid modifying published nexthop groups while they might be in use, otherwise we might see NULL ptr dereferences. In order to do that we allocate 2 nexthoup group structures upon nexthop creation and swap between them when we have to delete an entry. The reason is that we can't fail nexthop group removal, so we can't handle allocation failure thus we move the extra allocation on creation where we can safely fail and return ENOMEM. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:15 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add a dedicated flag for multipath next-hop groups With the introduction of resilient nexthop groups, there will be two types of multipath groups: the current hash-threshold "mpath" ones, and resilient groups. Both are multipath, but to determine the fact, the system needs to consider two flags. This might prove costly in the datapath. Therefore, introduce a new flag, that should be set for next-hop groups that have more than one nexthop, and should be considered multipath. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:14 +01:00
nexthop: Rename artifacts related to legacy multipath nexthop groups After resilient next-hop groups have been added recently, there are two types of multipath next-hop groups: the legacy "mpath", and the new "resilient". Calling the legacy next-hop group type "mpath" is unfortunate, because that describes the fact that a packet could be forwarded in one of several paths, which is also true for the resilient next-hop groups. Therefore, to make the naming clearer, rename various artifacts to reflect the assumptions made. Therefore as of this patch: - The flag for multipath groups is nh_grp_entry::is_multipath. This includes the legacy and resilient groups, as well as any future group types that behave as multipath groups. Functions that assume this have "mpath" in the name. - The flag for legacy multipath groups is nh_grp_entry::hash_threshold. Functions that assume this have "hthr" in the name. - The flag for resilient groups is nh_grp_entry::resilient. Functions that assume this have "res" in the name. Besides the above, struct nh_grp_entry::mpath was renamed to ::hthr as well. UAPI artifacts were obviously left intact. Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-26 14:20:22 +01:00
nexthop: Add implementation of resilient next-hop groups At this moment, there is only one type of next-hop group: an mpath group, which implements the hash-threshold algorithm. To select a next hop, hash-threshold algorithm first assigns a range of hashes to each next hop in the group, and then selects the next hop by comparing the SKB hash with the individual ranges. When a next hop is removed from the group, the ranges are recomputed, which leads to reassignment of parts of hash space from one next hop to another. While there will usually be some overlap between the previous and the new distribution, some traffic flows change the next hop that they resolve to. That causes problems e.g. as established TCP connections are reset, because the traffic is forwarded to a server that is not familiar with the connection. Resilient hashing is a technique to address the above problem. Resilient next-hop group has another layer of indirection between the group itself and its constituent next hops: a hash table. The selection algorithm uses a straightforward modulo operation to choose a hash bucket, and then reads the next hop that this bucket contains, and forwards traffic there. This indirection brings an important feature. In the hash-threshold algorithm, the range of hashes associated with a next hop must be continuous. With a hash table, mapping between the hash table buckets and the individual next hops is arbitrary. Therefore when a next hop is deleted the buckets that held it are simply reassigned to other next hops. When weights of next hops in a group are altered, it may be possible to choose a subset of buckets that are currently not used for forwarding traffic, and use those to satisfy the new next-hop distribution demands, keeping the "busy" buckets intact. This way, established flows are ideally kept being forwarded to the same endpoints through the same paths as before the next-hop group change. In a nutshell, the algorithm works as follows. Each next hop has a number of buckets that it wants to have, according to its weight and the number of buckets in the hash table. In case of an event that might cause bucket allocation change, the numbers for individual next hops are updated, similarly to how ranges are updated for mpath group next hops. Following that, a new "upkeep" algorithm runs, and for idle buckets that belong to a next hop that is currently occupying more buckets than it wants (it is "overweight"), it migrates the buckets to one of the next hops that has fewer buckets than it wants (it is "underweight"). If, after this, there are still underweight next hops, another upkeep run is scheduled to a future time. Chances are there are not enough "idle" buckets to satisfy the new demands. The algorithm has knobs to select both what it means for a bucket to be idle, and for whether and when to forcefully migrate buckets if there keeps being an insufficient number of idle buckets. There are three users of the resilient data structures. - The forwarding code accesses them under RCU, and does not modify them except for updating the time a selected bucket was last used. - Netlink code, running under RTNL, which may modify the data. - The delayed upkeep code, which may modify the data. This runs unlocked, and mutual exclusion between the RTNL code and the delayed upkeep is maintained by canceling the delayed work synchronously before the RTNL code touches anything. Later it restarts the delayed work if necessary. The RTNL code has to implement next-hop group replacement, next hop removal, etc. For removal, the mpath code uses a neat trick of having a backup next hop group structure, doing the necessary changes offline, and then RCU-swapping them in. However, the hash tables for resilient hashing are about an order of magnitude larger than the groups themselves (the size might be e.g. 4K entries), and it was felt that keeping two of them is an overkill. Both the primary next-hop group and the spare therefore use the same resilient table, and writers are careful to keep all references valid for the forwarding code. The hash table references next-hop group entries from the next-hop group that is currently in the primary role (i.e. not spare). During the transition from primary to spare, the table references a mix of both the primary group and the spare. When a next hop is deleted, the corresponding buckets are not set to NULL, but instead marked as empty, so that the pointer is valid and can be used by the forwarding code. The buckets are then migrated to a new next-hop group entry during upkeep. The only times that the hash table is invalid is the very beginning and very end of its lifetime. Between those points, it is always kept valid. This patch introduces the core support code itself. It does not handle notifications towards drivers, which are kept as if the group were an mpath one. It does not handle netlink either. The only bit currently exposed to user space is the new next-hop group type, and that is currently bounced. There is therefore no way to actually access this code. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:16 +01:00
nexthop: Fix fdb labeling for groups fdb nexthops are marked with a flag. For standalone nexthops, a flag was added to the nh_info struct. For groups that flag was added to struct nexthop when it should have been added to the group information. Fix by removing the flag from the nexthop struct and adding a flag to nh_group that mirrors nh_info and is really only a caching of the individual types. Add a helper, nexthop_is_fdb, for use by the vxlan code and fixup the internal code to use the flag from either nh_info or nh_group. v2 - propagate fdb_nh in remove_nh_grp_entry Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops") Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-08 20:54:43 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add implementation of resilient next-hop groups At this moment, there is only one type of next-hop group: an mpath group, which implements the hash-threshold algorithm. To select a next hop, hash-threshold algorithm first assigns a range of hashes to each next hop in the group, and then selects the next hop by comparing the SKB hash with the individual ranges. When a next hop is removed from the group, the ranges are recomputed, which leads to reassignment of parts of hash space from one next hop to another. While there will usually be some overlap between the previous and the new distribution, some traffic flows change the next hop that they resolve to. That causes problems e.g. as established TCP connections are reset, because the traffic is forwarded to a server that is not familiar with the connection. Resilient hashing is a technique to address the above problem. Resilient next-hop group has another layer of indirection between the group itself and its constituent next hops: a hash table. The selection algorithm uses a straightforward modulo operation to choose a hash bucket, and then reads the next hop that this bucket contains, and forwards traffic there. This indirection brings an important feature. In the hash-threshold algorithm, the range of hashes associated with a next hop must be continuous. With a hash table, mapping between the hash table buckets and the individual next hops is arbitrary. Therefore when a next hop is deleted the buckets that held it are simply reassigned to other next hops. When weights of next hops in a group are altered, it may be possible to choose a subset of buckets that are currently not used for forwarding traffic, and use those to satisfy the new next-hop distribution demands, keeping the "busy" buckets intact. This way, established flows are ideally kept being forwarded to the same endpoints through the same paths as before the next-hop group change. In a nutshell, the algorithm works as follows. Each next hop has a number of buckets that it wants to have, according to its weight and the number of buckets in the hash table. In case of an event that might cause bucket allocation change, the numbers for individual next hops are updated, similarly to how ranges are updated for mpath group next hops. Following that, a new "upkeep" algorithm runs, and for idle buckets that belong to a next hop that is currently occupying more buckets than it wants (it is "overweight"), it migrates the buckets to one of the next hops that has fewer buckets than it wants (it is "underweight"). If, after this, there are still underweight next hops, another upkeep run is scheduled to a future time. Chances are there are not enough "idle" buckets to satisfy the new demands. The algorithm has knobs to select both what it means for a bucket to be idle, and for whether and when to forcefully migrate buckets if there keeps being an insufficient number of idle buckets. There are three users of the resilient data structures. - The forwarding code accesses them under RCU, and does not modify them except for updating the time a selected bucket was last used. - Netlink code, running under RTNL, which may modify the data. - The delayed upkeep code, which may modify the data. This runs unlocked, and mutual exclusion between the RTNL code and the delayed upkeep is maintained by canceling the delayed work synchronously before the RTNL code touches anything. Later it restarts the delayed work if necessary. The RTNL code has to implement next-hop group replacement, next hop removal, etc. For removal, the mpath code uses a neat trick of having a backup next hop group structure, doing the necessary changes offline, and then RCU-swapping them in. However, the hash tables for resilient hashing are about an order of magnitude larger than the groups themselves (the size might be e.g. 4K entries), and it was felt that keeping two of them is an overkill. Both the primary next-hop group and the spare therefore use the same resilient table, and writers are careful to keep all references valid for the forwarding code. The hash table references next-hop group entries from the next-hop group that is currently in the primary role (i.e. not spare). During the transition from primary to spare, the table references a mix of both the primary group and the spare. When a next hop is deleted, the corresponding buckets are not set to NULL, but instead marked as empty, so that the pointer is valid and can be used by the forwarding code. The buckets are then migrated to a new next-hop group entry during upkeep. The only times that the hash table is invalid is the very beginning and very end of its lifetime. Between those points, it is always kept valid. This patch introduces the core support code itself. It does not handle notifications towards drivers, which are kept as if the group were an mpath one. It does not handle netlink either. The only bit currently exposed to user space is the new next-hop group type, and that is currently bounced. There is therefore no way to actually access this code. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:16 +01:00
net: nexthop: Replace zero-length array with flexible-array member The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28 18:14:11 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
nexthop: support for fdb ecmp nexthops This patch introduces ecmp nexthops and nexthop groups for mac fdb entries. In subsequent patches this is used by the vxlan driver fdb entries. The use case is E-VPN multihoming [1,2,3] which requires bridged vxlan traffic to be load balanced to remote switches (vteps) belonging to the same multi-homed ethernet segment (This is analogous to a multi-homed LAG but over vxlan). Changes include new nexthop flag NHA_FDB for nexthops referenced by fdb entries. These nexthops only have ip. This patch includes appropriate checks to avoid routes referencing such nexthops. example: $ip nexthop add id 12 via 172.16.1.2 fdb $ip nexthop add id 13 via 172.16.1.3 fdb $ip nexthop add id 102 group 12/13 fdb $bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self [1] E-VPN https://tools.ietf.org/html/rfc7432 [2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365 [3] LPC talk with mention of nexthop groups for L2 ecmp http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf v4 - fixed uninitialized variable reported by kernel test robot Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:13 -07:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: add support for notifiers This patch adds nexthop add/del notifiers. To be used by vxlan driver in a later patch. Could possibly be used by switchdev drivers in the future. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:15 -07:00
nexthop: Emit a notification when a nexthop is added Emit a notification in the nexthop notification chain when a new nexthop is added (not replaced). The nexthop can either be a new group or a single nexthop. The notification is sent after the nexthop is inserted into the red-black tree, as listeners might need to callback into the nexthop code with the nexthop ID in order to mark the nexthop as offloaded. A 'REPLACE' notification is emitted instead of 'ADD' as the distinction between the two is not important for in-kernel listeners. In case the listener is not familiar with the encoded nexthop ID, it can simply treat it as a new one. This is also consistent with the route offload API. Changes since RFC: * Reword commit message Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:29 +02:00
nexthop: Add data structures for resilient group notifications Add data structures that will be used for in-kernel notifications about addition / deletion of a resilient nexthop group and about changes to a hash bucket within a resilient group. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:17 +01:00
nexthop: add support for notifiers This patch adds nexthop add/del notifiers. To be used by vxlan driver in a later patch. Could possibly be used by switchdev drivers in the future. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:15 -07:00
nexthop: Use enum to encode notification type Currently there are only two types of in-kernel nexthop notification. The two are distinguished by the 'is_grp' boolean field in 'struct nh_notifier_info'. As more notification types are introduced for more next-hop group types, a boolean is not an easily extensible interface. Instead, convert it to an enum. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 13:49:17 +01:00
nexthop: Add data structures for resilient group notifications Add data structures that will be used for in-kernel notifications about addition / deletion of a resilient nexthop group and about changes to a hash bucket within a resilient group. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:17 +01:00
nexthop: Use enum to encode notification type Currently there are only two types of in-kernel nexthop notification. The two are distinguished by the 'is_grp' boolean field in 'struct nh_notifier_info'. As more notification types are introduced for more next-hop group types, a boolean is not an easily extensible interface. Instead, convert it to an enum. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 13:49:17 +01:00
nexthop: Add nexthop notification data structures Add data structures that will be used for nexthop replace and delete notifications in the previously introduced nexthop notification chain. New data structures are added instead of passing the existing nexthop code structures directly for several reasons. First, the existing structures encode a lot of bookkeeping information which is irrelevant for listeners of the notification chain. Second, the existing structures can be changed without worrying about introducing regressions in listeners since they are not accessed directly by them. Third, listeners of the notification chain do not need to each parse the relatively complex nexthop code structures. They are passing the required information in a simplified way. Note that a single 'has_encap' bit is added instead of the actual encapsulation information since current listeners do not support such nexthops. Changes since RFC: * s/is_encap/has_encap/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:23 +02:00
nexthop: Add data structures for resilient group notifications Add data structures that will be used for in-kernel notifications about addition / deletion of a resilient nexthop group and about changes to a hash bucket within a resilient group. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:17 +01:00
nexthop: Add nexthop notification data structures Add data structures that will be used for nexthop replace and delete notifications in the previously introduced nexthop notification chain. New data structures are added instead of passing the existing nexthop code structures directly for several reasons. First, the existing structures encode a lot of bookkeeping information which is irrelevant for listeners of the notification chain. Second, the existing structures can be changed without worrying about introducing regressions in listeners since they are not accessed directly by them. Third, listeners of the notification chain do not need to each parse the relatively complex nexthop code structures. They are passing the required information in a simplified way. Note that a single 'has_encap' bit is added instead of the actual encapsulation information since current listeners do not support such nexthops. Changes since RFC: * s/is_encap/has_encap/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:23 +02:00
nexthop: Use enum to encode notification type Currently there are only two types of in-kernel nexthop notification. The two are distinguished by the 'is_grp' boolean field in 'struct nh_notifier_info'. As more notification types are introduced for more next-hop group types, a boolean is not an easily extensible interface. Instead, convert it to an enum. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 13:49:17 +01:00
nexthop: Add nexthop notification data structures Add data structures that will be used for nexthop replace and delete notifications in the previously introduced nexthop notification chain. New data structures are added instead of passing the existing nexthop code structures directly for several reasons. First, the existing structures encode a lot of bookkeeping information which is irrelevant for listeners of the notification chain. Second, the existing structures can be changed without worrying about introducing regressions in listeners since they are not accessed directly by them. Third, listeners of the notification chain do not need to each parse the relatively complex nexthop code structures. They are passing the required information in a simplified way. Note that a single 'has_encap' bit is added instead of the actual encapsulation information since current listeners do not support such nexthops. Changes since RFC: * s/is_encap/has_encap/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:23 +02:00
nexthop: Add data structures for resilient group notifications Add data structures that will be used for in-kernel notifications about addition / deletion of a resilient nexthop group and about changes to a hash bucket within a resilient group. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:17 +01:00
nexthop: Add nexthop notification data structures Add data structures that will be used for nexthop replace and delete notifications in the previously introduced nexthop notification chain. New data structures are added instead of passing the existing nexthop code structures directly for several reasons. First, the existing structures encode a lot of bookkeeping information which is irrelevant for listeners of the notification chain. Second, the existing structures can be changed without worrying about introducing regressions in listeners since they are not accessed directly by them. Third, listeners of the notification chain do not need to each parse the relatively complex nexthop code structures. They are passing the required information in a simplified way. Note that a single 'has_encap' bit is added instead of the actual encapsulation information since current listeners do not support such nexthops. Changes since RFC: * s/is_encap/has_encap/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:23 +02:00
nexthop: Pass extack to register_nexthop_notifier() This will be used by the next patch which extends the function to replay all the existing nexthops to the notifier block being registered. Device drivers will be able to pass extack to the function since it is passed to them upon reload from devlink. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:34 +02:00
nexthop: add support for notifiers This patch adds nexthop add/del notifiers. To be used by vxlan driver in a later patch. Could possibly be used by switchdev drivers in the future. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:15 -07:00
nexthop: Allow setting "offload" and "trap" indications on nexthops Add a function that can be called by device drivers to set "offload" or "trap" indication on nexthops following nexthop notifications. Changes since RFC: * s/nexthop_hw_flags_set/nexthop_set_hw_flags/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 15:30:28 +02:00
nexthop: Allow setting "offload" and "trap" indication of nexthop buckets Add a function that can be called by device drivers to set "offload" or "trap" indication on nexthop buckets following nexthop notifications and other changes such as a neighbour becoming invalid. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:19 +01:00
nexthop: Allow reporting activity of nexthop buckets The kernel periodically checks the idle time of nexthop buckets to determine if they are idle and can be re-populated with a new nexthop. When the resilient nexthop group is offloaded to hardware, the kernel will not see activity on nexthop buckets unless it is reported from hardware. Add a function that can be periodically called by device drivers to report activity on nexthop buckets after querying it from the underlying device. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:20 +01:00
nexthop: add support for notifiers This patch adds nexthop add/del notifiers. To be used by vxlan driver in a later patch. Could possibly be used by switchdev drivers in the future. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:15 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
nexthop: Fix fdb labeling for groups fdb nexthops are marked with a flag. For standalone nexthops, a flag was added to the nh_info struct. For groups that flag was added to struct nexthop when it should have been added to the group information. Fix by removing the flag from the nexthop struct and adding a flag to nh_group that mirrors nh_info and is really only a caching of the individual types. Add a helper, nexthop_is_fdb, for use by the vxlan code and fixup the internal code to use the flag from either nh_info or nh_group. v2 - propagate fdb_nh in remove_nh_grp_entry Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops") Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-08 20:54:43 -06:00
vxlan: Remove access to nexthop group struct vxlan driver should be using helpers to access nexthop struct internals. Remove open check if whether nexthop is multipath in favor of the existing nexthop_is_multipath helper. Add a new helper, nexthop_has_v4, to cover the need to check has_v4 in a group. Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries") Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-09 17:27:28 -06:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add a dedicated flag for multipath next-hop groups With the introduction of resilient nexthop groups, there will be two types of multipath groups: the current hash-threshold "mpath" ones, and resilient groups. Both are multipath, but to determine the fact, the system needs to consider two flags. This might prove costly in the datapath. Therefore, introduce a new flag, that should be set for next-hop groups that have more than one nexthop, and should be considered multipath. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:14 +01:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Add a dedicated flag for multipath next-hop groups With the introduction of resilient nexthop groups, there will be two types of multipath groups: the current hash-threshold "mpath" ones, and resilient groups. Both are multipath, but to determine the fact, the system needs to consider two flags. This might prove costly in the datapath. Therefore, introduce a new flag, that should be set for next-hop groups that have more than one nexthop, and should be considered multipath. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:14 +01:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: off by one in nexthop_mpath_select() The nhg->nh_entries[] array is allocated in nexthop_grp_alloc() and it has nhg->num_nh elements so this check should be >= instead of >. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07 18:31:07 +03:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Properly update v4 routes with v6 nexthop When creating a v4 route that uses a v6 nexthop from a nexthop group. Allow the kernel to properly send the nexthop as v6 via the RTA_VIA attribute. Broken behavior: $ ip nexthop add via fe80::9 dev eth0 $ ip nexthop show id 1 via fe80::9 dev eth0 scope link $ ip route add 4.5.6.7/32 nhid 1 $ ip route show default via 10.0.2.2 dev eth0 4.5.6.7 nhid 1 via 254.128.0.0 dev eth0 10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15 $ Fixed behavior: $ ip nexthop add via fe80::9 dev eth0 $ ip nexthop show id 1 via fe80::9 dev eth0 scope link $ ip route add 4.5.6.7/32 nhid 1 $ ip route show default via 10.0.2.2 dev eth0 4.5.6.7 nhid 1 via inet6 fe80::9 dev eth0 10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15 $ v2, v3: Addresses code review comments from David Ahern Fixes: dcb1ecb50edf (“ipv4: Prepare for fib6_nh from a nexthop object”) Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-04 10:11:58 -04:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: ipv4: Fix rtnexthop len when RTA_FLOW is present Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop() to get the length of rtnexthop correct. Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info") Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-23 23:03:19 +08:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add support for nexthop groups Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:08 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
nexthop: Add a dedicated flag for multipath next-hop groups With the introduction of resilient nexthop groups, there will be two types of multipath groups: the current hash-threshold "mpath" ones, and resilient groups. Both are multipath, but to determine the fact, the system needs to consider two flags. This might prove costly in the datapath. Therefore, introduce a new flag, that should be set for next-hop groups that have more than one nexthop, and should be considered multipath. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 19:03:14 +01:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Refactor nhc evaluation in fib_table_lookup FIB lookups can return an entry that references an external nexthop. While walking the nexthop struct we do not want to make multiple calls into the nexthop code which can result in 2 different structs getting accessed - one returning the number of paths the rest of the loop seeing a different nh_grp struct. If the nexthop group shrunk, the result is an attempt to access a fib_nh_common that does not exist for the new nh_grp struct but did for the old one. To fix that move the device evaluation code to a helper that can be used for inline fib_nh path as well as external nexthops. Update the existing check for fi->nh in fib_table_lookup to call a new helper, nexthop_get_nhc_lookup, which walks the external nexthop with a single rcu dereference. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:17 -06:00
ipv4: nexthop version of fib_info_nh_uses_dev Similar to the last path, need to fix fib_info_nh_uses_dev for external nexthops to avoid referencing multiple nh_grp structs. Move the device check in fib_info_nh_uses_dev to a helper and create a nexthop version that is called if the fib_info uses an external nexthop. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:18 -06:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:51 -07:00
ipv4: Use accessors for fib_info nexthop data Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:49 -07:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
ipv6: fix suspecious RCU usage warning Syzbot reported the suspecious RCU usage in nexthop_fib6_nh() when called from ipv6_route_seq_show(). The reason is ipv6_route_seq_start() calls rcu_read_lock_bh(), while nexthop_fib6_nh() calls rcu_dereference_rtnl(). The fix proposed is to add a variant of nexthop_fib6_nh() to use rcu_dereference_bh_rtnl() for ipv6_route_seq_show(). The reported trace is as follows: ./include/net/nexthop.h:416 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.0/17895: at: seq_read+0x71/0x12a0 fs/seq_file.c:169 at: seq_file_net include/linux/seq_file_net.h:19 [inline] at: ipv6_route_seq_start+0xaf/0x300 net/ipv6/ip6_fib.c:2616 stack backtrace: CPU: 1 PID: 17895 Comm: syz-executor.0 Not tainted 4.15.0-syzkaller #0 Call Trace: [<ffffffff849edf9e>] __dump_stack lib/dump_stack.c:17 [inline] [<ffffffff849edf9e>] dump_stack+0xd8/0x147 lib/dump_stack.c:53 [<ffffffff8480b7fa>] lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5745 [<ffffffff8459ada6>] nexthop_fib6_nh include/net/nexthop.h:416 [inline] [<ffffffff8459ada6>] ipv6_route_native_seq_show net/ipv6/ip6_fib.c:2488 [inline] [<ffffffff8459ada6>] ipv6_route_seq_show+0x436/0x7a0 net/ipv6/ip6_fib.c:2673 [<ffffffff81c556df>] seq_read+0xccf/0x12a0 fs/seq_file.c:276 [<ffffffff81dbc62c>] proc_reg_read+0x10c/0x1d0 fs/proc/inode.c:231 [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:714 [inline] [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:701 [inline] [<ffffffff81bc28ae>] do_iter_read+0x49e/0x660 fs/read_write.c:935 [<ffffffff81bc81ab>] vfs_readv+0xfb/0x170 fs/read_write.c:997 [<ffffffff81c88847>] kernel_readv fs/splice.c:361 [inline] [<ffffffff81c88847>] default_file_splice_read+0x487/0x9c0 fs/splice.c:416 [<ffffffff81c86189>] do_splice_to+0x129/0x190 fs/splice.c:879 [<ffffffff81c86f66>] splice_direct_to_actor+0x256/0x890 fs/splice.c:951 [<ffffffff81c8777d>] do_splice_direct+0x1dd/0x2b0 fs/splice.c:1060 [<ffffffff81bc4747>] do_sendfile+0x597/0xce0 fs/read_write.c:1459 [<ffffffff81bca205>] SYSC_sendfile64 fs/read_write.c:1520 [inline] [<ffffffff81bca205>] SyS_sendfile64+0x155/0x170 fs/read_write.c:1506 [<ffffffff81015fcf>] do_syscall_64+0x1ff/0x310 arch/x86/entry/common.c:305 [<ffffffff84a00076>] entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Wei Wang <weiwan@google.com> Cc: David Ahern <dsahern@kernel.org> Cc: Ido Schimmel <idosch@idosch.org> Cc: Petr Machata <petrm@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-09 18:20:35 -08:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
nexthop: Expand nexthop_is_multipath in a few places I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 12:56:16 -06:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
ipv6: fix suspecious RCU usage warning Syzbot reported the suspecious RCU usage in nexthop_fib6_nh() when called from ipv6_route_seq_show(). The reason is ipv6_route_seq_start() calls rcu_read_lock_bh(), while nexthop_fib6_nh() calls rcu_dereference_rtnl(). The fix proposed is to add a variant of nexthop_fib6_nh() to use rcu_dereference_bh_rtnl() for ipv6_route_seq_show(). The reported trace is as follows: ./include/net/nexthop.h:416 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.0/17895: at: seq_read+0x71/0x12a0 fs/seq_file.c:169 at: seq_file_net include/linux/seq_file_net.h:19 [inline] at: ipv6_route_seq_start+0xaf/0x300 net/ipv6/ip6_fib.c:2616 stack backtrace: CPU: 1 PID: 17895 Comm: syz-executor.0 Not tainted 4.15.0-syzkaller #0 Call Trace: [<ffffffff849edf9e>] __dump_stack lib/dump_stack.c:17 [inline] [<ffffffff849edf9e>] dump_stack+0xd8/0x147 lib/dump_stack.c:53 [<ffffffff8480b7fa>] lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5745 [<ffffffff8459ada6>] nexthop_fib6_nh include/net/nexthop.h:416 [inline] [<ffffffff8459ada6>] ipv6_route_native_seq_show net/ipv6/ip6_fib.c:2488 [inline] [<ffffffff8459ada6>] ipv6_route_seq_show+0x436/0x7a0 net/ipv6/ip6_fib.c:2673 [<ffffffff81c556df>] seq_read+0xccf/0x12a0 fs/seq_file.c:276 [<ffffffff81dbc62c>] proc_reg_read+0x10c/0x1d0 fs/proc/inode.c:231 [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:714 [inline] [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:701 [inline] [<ffffffff81bc28ae>] do_iter_read+0x49e/0x660 fs/read_write.c:935 [<ffffffff81bc81ab>] vfs_readv+0xfb/0x170 fs/read_write.c:997 [<ffffffff81c88847>] kernel_readv fs/splice.c:361 [inline] [<ffffffff81c88847>] default_file_splice_read+0x487/0x9c0 fs/splice.c:416 [<ffffffff81c86189>] do_splice_to+0x129/0x190 fs/splice.c:879 [<ffffffff81c86f66>] splice_direct_to_actor+0x256/0x890 fs/splice.c:951 [<ffffffff81c8777d>] do_splice_direct+0x1dd/0x2b0 fs/splice.c:1060 [<ffffffff81bc4747>] do_sendfile+0x597/0xce0 fs/read_write.c:1459 [<ffffffff81bca205>] SYSC_sendfile64 fs/read_write.c:1520 [inline] [<ffffffff81bca205>] SyS_sendfile64+0x155/0x170 fs/read_write.c:1506 [<ffffffff81015fcf>] do_syscall_64+0x1ff/0x310 arch/x86/entry/common.c:305 [<ffffffff84a00076>] entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Wei Wang <weiwan@google.com> Cc: David Ahern <dsahern@kernel.org> Cc: Ido Schimmel <idosch@idosch.org> Cc: Petr Machata <petrm@nvidia.com> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-09 18:20:35 -08:00
ipv6: Plumb support for nexthop object in a fib6_info Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 20:19:52 -07:00
nexthops: Add ipv6 helper to walk all fib6_nh in a nexthop struct IPv6 has traditionally had a single fib6_nh per fib6_info. With nexthops we can have multiple fib6_nh associated with a fib6_info. Add a nexthop helper to invoke a callback for each fib6_nh in a 'struct nexthop'. If the callback returns non-0, the loop is stopped and the return value passed to the caller. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-08 14:53:22 -07:00
nexthop: support for fdb ecmp nexthops This patch introduces ecmp nexthops and nexthop groups for mac fdb entries. In subsequent patches this is used by the vxlan driver fdb entries. The use case is E-VPN multihoming [1,2,3] which requires bridged vxlan traffic to be load balanced to remote switches (vteps) belonging to the same multi-homed ethernet segment (This is analogous to a multi-homed LAG but over vxlan). Changes include new nexthop flag NHA_FDB for nexthops referenced by fdb entries. These nexthops only have ip. This patch includes appropriate checks to avoid routes referencing such nexthops. example: $ip nexthop add id 12 via 172.16.1.2 fdb $ip nexthop add id 13 via 172.16.1.3 fdb $ip nexthop add id 102 group 12/13 fdb $bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self [1] E-VPN https://tools.ietf.org/html/rfc7432 [2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365 [3] LPC talk with mention of nexthop groups for L2 ecmp http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf v4 - fixed uninitialized variable reported by kernel test robot Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21 22:26:13 -07:00
net: Initial nexthop code Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 14:43:04 -07:00