From f6e96d72f64a83b31655ce504a1029b155c16966 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:00 +0100 Subject: [PATCH 1/7] netconsole: add an address family to struct inet_addr netconsole_target stores a single 'bool ipv6' to denote the target's address family. This makes it hard to detect conditions like "no address set" or ipv4/ipv6 mixup between local_ip and remote_ip. Add a 'family' field to inet_addr so each address stores its own address family: AF_UNSPEC while unset, else AF_INET or AF_INET6. Nothing reads the new field yet. The next patch switches the users over and removes the bool. No functional change. Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-1-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 24 +++++++++++++++--------- include/linux/netpoll.h | 10 +++++++--- 2 files changed, 22 insertions(+), 12 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index b358e5c36735..432b66cf111a 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -225,7 +225,7 @@ struct netconsole_target { bool extended; bool release; struct netpoll np; - union inet_addr local_ip, remote_ip; + struct inet_addr local_ip, remote_ip; bool ipv6; u16 local_port, remote_port; u8 remote_mac[ETH_ALEN]; @@ -428,6 +428,7 @@ static int netcons_take_ipv6(struct netconsole_target *nt, continue; /* Got the IP, let's return */ nt->local_ip.in6 = ifp->addr; + nt->local_ip.family = AF_INET6; err = 0; break; } @@ -469,6 +470,7 @@ static int netcons_take_ipv4(struct netconsole_target *nt, } nt->local_ip.ip = ifa->ifa_local; + nt->local_ip.family = AF_INET; np_info(np, "local IP %pI4\n", &nt->local_ip.ip); return 0; @@ -741,10 +743,10 @@ static void netconsole_print_banner(struct netconsole_target *nt) np_info(np, "remote ethernet address %pM\n", nt->remote_mac); } -/* Parse the string and populate the `inet_addr` union. Return 0 if IPv4 is +/* Parse the string and populate the `inet_addr` struct. Return 0 if IPv4 is * populated, 1 if IPv6 is populated, and -1 upon failure. */ -static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) +static int netpoll_parse_ip_addr(const char *str, struct inet_addr *addr) { const char *end = NULL; int len; @@ -756,14 +758,18 @@ static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) if (str[len - 1] == '\n') len -= 1; - if (in4_pton(str, len, (void *)addr, -1, &end) > 0 && - (!end || *end == 0 || *end == '\n')) + if (in4_pton(str, len, (void *)&addr->ip, -1, &end) > 0 && + (!end || *end == 0 || *end == '\n')) { + addr->family = AF_INET; return 0; + } if (IS_ENABLED(CONFIG_IPV6) && - in6_pton(str, len, (void *)addr, -1, &end) > 0 && - (!end || *end == 0 || *end == '\n')) + in6_pton(str, len, (void *)&addr->in6, -1, &end) > 0 && + (!end || *end == 0 || *end == '\n')) { + addr->family = AF_INET6; return 1; + } return -1; } @@ -871,7 +877,7 @@ static ssize_t local_ip_show(struct config_item *item, char *buf) if (nt->ipv6) return sysfs_emit(buf, "%pI6c\n", &nt->local_ip.in6); else - return sysfs_emit(buf, "%pI4\n", &nt->local_ip); + return sysfs_emit(buf, "%pI4\n", &nt->local_ip.ip); } static ssize_t remote_ip_show(struct config_item *item, char *buf) @@ -881,7 +887,7 @@ static ssize_t remote_ip_show(struct config_item *item, char *buf) if (nt->ipv6) return sysfs_emit(buf, "%pI6c\n", &nt->remote_ip.in6); else - return sysfs_emit(buf, "%pI4\n", &nt->remote_ip); + return sysfs_emit(buf, "%pI4\n", &nt->remote_ip.ip); } static ssize_t local_mac_show(struct config_item *item, char *buf) diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index 1c6b1eec5efd..de97f001a0f9 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -16,9 +16,13 @@ #include #include -union inet_addr { - __be32 ip; - struct in6_addr in6; +struct inet_addr { + /* Address family: AF_UNSPEC when unset, else AF_INET or AF_INET6 */ + u8 family; + union { + __be32 ip; + struct in6_addr in6; + }; }; struct netpoll { From 46b3f9e7e761d304986860804715af07381df4f1 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:01 +0100 Subject: [PATCH 2/7] netconsole: use the address family instead of the ipv6 flag Now that we have the address family in inet_addr, use that and remove nt->ipv6. We no longer need netcons_local_ip_unset() to check that all bytes are zeroes, as that is now denoted by (family == AF_UNSPEC). Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-2-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 82 +++++++++++----------------------------- 1 file changed, 23 insertions(+), 59 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 432b66cf111a..351754d53cf9 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -195,7 +195,6 @@ struct netcons_userdata { * local_mac (read-only) * @local_ip: Source IP address of the target (read-write). * @remote_ip: Destination IP address of the target (read-write). - * @ipv6: Whether the target addresses are IPv6 (read-write). * @local_port: Source UDP port of the target (read-write). * @remote_port: Destination UDP port of the target (read-write). * @remote_mac: Destination ethernet address of the target (read-write). @@ -226,7 +225,6 @@ struct netconsole_target { bool release; struct netpoll np; struct inet_addr local_ip, remote_ip; - bool ipv6; u16 local_port, remote_port; u8 remote_mac[ETH_ALEN]; /* protected by target_list_lock; +1 gives scnprintf() room for its @@ -476,23 +474,6 @@ static int netcons_take_ipv4(struct netconsole_target *nt, return 0; } -/* - * Test whether the caller left nt->local_ip unset, so that - * netcons_netpoll_setup() should auto-populate it from the egress device. - * - * nt->local_ip is a union of __be32 (IPv4) and struct in6_addr (IPv6), - * so an IPv6 address whose first 4 bytes are zero (e.g. ::1, ::2, - * IPv4-mapped ::ffff:a.b.c.d) must not be tested via the IPv4 arm — - * doing so would misclassify a caller-supplied address as unset and - * silently overwrite it with whatever address the device exposes. - */ -static bool netcons_local_ip_unset(const struct netconsole_target *nt) -{ - if (nt->ipv6) - return ipv6_addr_any(&nt->local_ip.in6); - return !nt->local_ip.ip; -} - static int netcons_netpoll_setup(struct netconsole_target *nt) { struct net *net = current->nsproxy->net_ns; @@ -538,16 +519,13 @@ static int netcons_netpoll_setup(struct netconsole_target *nt) rtnl_lock(); } - if (netcons_local_ip_unset(nt)) { - if (!nt->ipv6) { - err = netcons_take_ipv4(nt, ndev); - if (err) - goto put; - } else { + if (nt->local_ip.family == AF_UNSPEC) { + if (nt->remote_ip.family == AF_INET6) err = netcons_take_ipv6(nt, ndev); - if (err) - goto put; - } + else + err = netcons_take_ipv4(nt, ndev); + if (err) + goto put; ip_overwritten = true; } @@ -729,22 +707,22 @@ static void netconsole_print_banner(struct netconsole_target *nt) struct netpoll *np = &nt->np; np_info(np, "local port %d\n", nt->local_port); - if (nt->ipv6) + if (nt->local_ip.family == AF_INET6) np_info(np, "local IPv6 address %pI6c\n", &nt->local_ip.in6); else np_info(np, "local IPv4 address %pI4\n", &nt->local_ip.ip); np_info(np, "interface name '%s'\n", np->dev_name); np_info(np, "local ethernet address '%pM'\n", np->dev_mac); np_info(np, "remote port %d\n", nt->remote_port); - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) np_info(np, "remote IPv6 address %pI6c\n", &nt->remote_ip.in6); else np_info(np, "remote IPv4 address %pI4\n", &nt->remote_ip.ip); np_info(np, "remote ethernet address %pM\n", nt->remote_mac); } -/* Parse the string and populate the `inet_addr` struct. Return 0 if IPv4 is - * populated, 1 if IPv6 is populated, and -1 upon failure. +/* Parse the string and populate the `inet_addr` struct. Return 0 on success + * and -1 upon failure. */ static int netpoll_parse_ip_addr(const char *str, struct inet_addr *addr) { @@ -768,7 +746,7 @@ static int netpoll_parse_ip_addr(const char *str, struct inet_addr *addr) in6_pton(str, len, (void *)&addr->in6, -1, &end) > 0 && (!end || *end == 0 || *end == '\n')) { addr->family = AF_INET6; - return 1; + return 0; } return -1; @@ -874,7 +852,7 @@ static ssize_t local_ip_show(struct config_item *item, char *buf) { struct netconsole_target *nt = to_target(item); - if (nt->ipv6) + if (nt->local_ip.family == AF_INET6) return sysfs_emit(buf, "%pI6c\n", &nt->local_ip.in6); else return sysfs_emit(buf, "%pI4\n", &nt->local_ip.ip); @@ -884,7 +862,7 @@ static ssize_t remote_ip_show(struct config_item *item, char *buf) { struct netconsole_target *nt = to_target(item); - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) return sysfs_emit(buf, "%pI6c\n", &nt->remote_ip.in6); else return sysfs_emit(buf, "%pI4\n", &nt->remote_ip.ip); @@ -1232,7 +1210,6 @@ static ssize_t local_ip_store(struct config_item *item, const char *buf, { struct netconsole_target *nt = to_target(item); ssize_t ret = -EINVAL; - int ipv6; dynamic_netconsole_mutex_lock(); if (nt->state == STATE_ENABLED) { @@ -1241,10 +1218,8 @@ static ssize_t local_ip_store(struct config_item *item, const char *buf, goto out_unlock; } - ipv6 = netpoll_parse_ip_addr(buf, &nt->local_ip); - if (ipv6 == -1) + if (netpoll_parse_ip_addr(buf, &nt->local_ip) < 0) goto out_unlock; - nt->ipv6 = !!ipv6; ret = count; out_unlock: @@ -1257,7 +1232,6 @@ static ssize_t remote_ip_store(struct config_item *item, const char *buf, { struct netconsole_target *nt = to_target(item); ssize_t ret = -EINVAL; - int ipv6; dynamic_netconsole_mutex_lock(); if (nt->state == STATE_ENABLED) { @@ -1266,10 +1240,8 @@ static ssize_t remote_ip_store(struct config_item *item, const char *buf, goto out_unlock; } - ipv6 = netpoll_parse_ip_addr(buf, &nt->remote_ip); - if (ipv6 == -1) + if (netpoll_parse_ip_addr(buf, &nt->remote_ip) < 0) goto out_unlock; - nt->ipv6 = !!ipv6; ret = count; out_unlock: @@ -2078,7 +2050,7 @@ static void netpoll_udp_checksum(struct netconsole_target *nt, /* check needs to be set, since it will be consumed in csum_partial */ udph->check = 0; - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) udph->check = csum_ipv6_magic(&nt->local_ip.in6, &nt->remote_ip.in6, udp_len, IPPROTO_UDP, @@ -2119,7 +2091,7 @@ static void push_eth(struct netconsole_target *nt, struct sk_buff *skb) skb_reset_mac_header(skb); ether_addr_copy(eth->h_source, np->dev->dev_addr); ether_addr_copy(eth->h_dest, nt->remote_mac); - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) eth->h_proto = htons(ETH_P_IPV6); else eth->h_proto = htons(ETH_P_IP); @@ -2188,7 +2160,7 @@ static int netpoll_send_udp(struct netconsole_target *nt, const char *msg, WARN_ON_ONCE(!irqs_disabled()); udp_len = len + sizeof(struct udphdr); - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) ip_len = udp_len + sizeof(struct ipv6hdr); else ip_len = udp_len + sizeof(struct iphdr); @@ -2204,7 +2176,7 @@ static int netpoll_send_udp(struct netconsole_target *nt, const char *msg, skb_put(skb, len); push_udp(nt, skb, len); - if (nt->ipv6) + if (nt->remote_ip.family == AF_INET6) push_ipv6(nt, skb, len); else push_ipv4(nt, skb, len); @@ -2533,10 +2505,8 @@ __releases(&target_list_lock) static int netconsole_parser_cmdline(struct netconsole_target *nt, char *opt) { struct netpoll *np = &nt->np; - bool ipversion_set = false; char *cur = opt; char *delim; - int ipv6; if (*cur != '@') { delim = strchr(cur, '@'); @@ -2550,16 +2520,12 @@ static int netconsole_parser_cmdline(struct netconsole_target *nt, char *opt) cur++; if (*cur != '/') { - ipversion_set = true; delim = strchr(cur, '/'); if (!delim) goto parse_failed; *delim = 0; - ipv6 = netpoll_parse_ip_addr(cur, &nt->local_ip); - if (ipv6 < 0) + if (netpoll_parse_ip_addr(cur, &nt->local_ip) < 0) goto parse_failed; - else - nt->ipv6 = (bool)ipv6; cur = delim; } cur++; @@ -2601,13 +2567,11 @@ static int netconsole_parser_cmdline(struct netconsole_target *nt, char *opt) if (!delim) goto parse_failed; *delim = 0; - ipv6 = netpoll_parse_ip_addr(cur, &nt->remote_ip); - if (ipv6 < 0) + if (netpoll_parse_ip_addr(cur, &nt->remote_ip) < 0) goto parse_failed; - else if (ipversion_set && nt->ipv6 != (bool)ipv6) + if (nt->local_ip.family != AF_UNSPEC && + nt->local_ip.family != nt->remote_ip.family) goto parse_failed; - else - nt->ipv6 = (bool)ipv6; cur = delim + 1; if (*cur != 0) { From 2e949954908bd5bcca2fe3cdaac9c42c88275c0b Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:02 +0100 Subject: [PATCH 3/7] netconsole: reject enabling a target with no remote IP address The command-line path already requires a remote address, but if a user creates a dynamic target and enables it without setting a remote address, we currently try sending netconsole traffic to "0.0.0.0". Refuse to enable a target if the remote address is unset. Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-3-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 351754d53cf9..4af4f3039d4c 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -483,6 +483,11 @@ static int netcons_netpoll_setup(struct netconsole_target *nt) bool ip_overwritten = false; int err; + if (nt->remote_ip.family == AF_UNSPEC) { + np_err(np, "remote IP address not configured, aborting\n"); + return -EDESTADDRREQ; + } + rtnl_lock(); if (np->dev_name[0]) ndev = __dev_get_by_name(net, np->dev_name); From 32535a1ea962e9123506463ac3e0d1473d492059 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:03 +0100 Subject: [PATCH 4/7] netconsole: reject a target mixing IPv4 and IPv6 addresses The local_ip and remote_ip configfs attributes are written independently and nothing stops a user from mixing ipv4 and ipv6. This leads to an ipv4 address being zero-extended into an ipv6 header or an ipv6 address being truncated to its first 4 bytes for an ipv4 header. The command-line parser already refuses such a mismatch. This adds a similar check when a dynamic target is being enabled. Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-4-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 4af4f3039d4c..abcc8515ddd2 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -488,6 +488,12 @@ static int netcons_netpoll_setup(struct netconsole_target *nt) return -EDESTADDRREQ; } + if (nt->local_ip.family != AF_UNSPEC && + nt->local_ip.family != nt->remote_ip.family) { + np_err(np, "local and remote IP address families differ, aborting\n"); + return -EINVAL; + } + rtnl_lock(); if (np->dev_name[0]) ndev = __dev_get_by_name(net, np->dev_name); From 56ddc8d48e75f48df938f5df80e2f99a0c3548d3 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:04 +0100 Subject: [PATCH 5/7] netconsole: show empty string for an unset IP address An unset address (local_ip/remote_ip), now denoted by AF_UNSPEC, currently shows "0.0.0.0" in configfs. Print an empty string instead, which is more clear. In netconsole_print_banner() we can be even more explicit about it, as we don't have the risk of userspace trying to parse it. Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-5-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index abcc8515ddd2..1f18d0a7d2dd 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -718,14 +718,18 @@ static void netconsole_print_banner(struct netconsole_target *nt) struct netpoll *np = &nt->np; np_info(np, "local port %d\n", nt->local_port); - if (nt->local_ip.family == AF_INET6) + if (nt->local_ip.family == AF_UNSPEC) + np_info(np, "local IP unset\n"); + else if (nt->local_ip.family == AF_INET6) np_info(np, "local IPv6 address %pI6c\n", &nt->local_ip.in6); else np_info(np, "local IPv4 address %pI4\n", &nt->local_ip.ip); np_info(np, "interface name '%s'\n", np->dev_name); np_info(np, "local ethernet address '%pM'\n", np->dev_mac); np_info(np, "remote port %d\n", nt->remote_port); - if (nt->remote_ip.family == AF_INET6) + if (nt->remote_ip.family == AF_UNSPEC) + np_info(np, "remote IP unset\n"); + else if (nt->remote_ip.family == AF_INET6) np_info(np, "remote IPv6 address %pI6c\n", &nt->remote_ip.in6); else np_info(np, "remote IPv4 address %pI4\n", &nt->remote_ip.ip); @@ -863,6 +867,8 @@ static ssize_t local_ip_show(struct config_item *item, char *buf) { struct netconsole_target *nt = to_target(item); + if (nt->local_ip.family == AF_UNSPEC) + return sysfs_emit(buf, "\n"); if (nt->local_ip.family == AF_INET6) return sysfs_emit(buf, "%pI6c\n", &nt->local_ip.in6); else @@ -873,6 +879,8 @@ static ssize_t remote_ip_show(struct config_item *item, char *buf) { struct netconsole_target *nt = to_target(item); + if (nt->remote_ip.family == AF_UNSPEC) + return sysfs_emit(buf, "\n"); if (nt->remote_ip.family == AF_INET6) return sysfs_emit(buf, "%pI6c\n", &nt->remote_ip.in6); else From 7be9bfb7689e875fc94b711dcafe27c86413c966 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:05 +0100 Subject: [PATCH 6/7] netconsole: move struct inet_addr into netconsole.c The struct inet_addr lives in netpoll.h, but since commit a1116396476f ("netconsole: move local_ip/remote_ip/ipv6 to netconsole_target") the only user is netconsole. Move the definition into netconsole.c Suggested-by: Breno Leitao Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-6-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 9 +++++++++ include/linux/netpoll.h | 9 --------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 1f18d0a7d2dd..267254f046de 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -151,6 +151,15 @@ enum target_state { STATE_DEACTIVATED, }; +struct inet_addr { + /* Address family: AF_UNSPEC when unset, else AF_INET or AF_INET6 */ + u8 family; + union { + __be32 ip; + struct in6_addr in6; + }; +}; + /** * struct netcons_userdata - Formatted userdata payload of a target. * @rcu: Used to free the payload after a grace period. diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index de97f001a0f9..ec0821a5b02d 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -16,15 +16,6 @@ #include #include -struct inet_addr { - /* Address family: AF_UNSPEC when unset, else AF_INET or AF_INET6 */ - u8 family; - union { - __be32 ip; - struct in6_addr in6; - }; -}; - struct netpoll { struct net_device *dev; netdevice_tracker dev_tracker; From a4b9392ef046bd8a165fb5091adebc2c6ea46890 Mon Sep 17 00:00:00 2001 From: Gustavo Luiz Duarte Date: Thu, 3 Sep 2026 17:26:06 +0100 Subject: [PATCH 7/7] docs: netconsole: document local_ip auto-selection An unset local_ip is auto-populated from the egress interface at enable time, but any value the user writes, including 0.0.0.0, is used as-is. This deviates from the behavior prior to "netconsole: use the address family instead of the ipv6 flag", which interpreted 0.0.0.0 as unset. Document this so the distinction between "unset" and "set to 0.0.0.0" is clear. Reviewed-by: Breno Leitao Signed-off-by: Gustavo Luiz Duarte Link: https://patch.msgid.link/20260903-netcons_ipv6-v4-7-bdd183c844d3@gmail.com Signed-off-by: Jakub Kicinski --- Documentation/networking/netconsole.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst index 4ab5d7b05cf1..694bca4803d5 100644 --- a/Documentation/networking/netconsole.rst +++ b/Documentation/networking/netconsole.rst @@ -141,6 +141,11 @@ The interface exposes these parameters of a netconsole target to userspace: transmit_errors Number of packet send errors (read-only) =============== ================================= ============ +local_ip is optional: if it is left unset, netconsole derives a source +address from the egress interface when the target is enabled. Writing any +value to it, including 0.0.0.0, uses that value verbatim and disables the +automatic selection. + The "enabled" attribute is also used to control whether the parameters of a target can be updated or not -- you can modify the parameters of only disabled targets (i.e. if "enabled" is 0).