linux/include/net/request_sock.h

241 lines
6.5 KiB

tcp: better retrans tracking for defer-accept For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Elliott Hughes <enh@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-27 23:16:46 +00:00
tcp: better retrans tracking for defer-accept For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Elliott Hughes <enh@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-27 23:16:46 +00:00
tcp: better retrans tracking for defer-accept For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Elliott Hughes <enh@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-27 23:16:46 +00:00
inet: clear num_timeout reqsk_alloc() KMSAN caught uninit-value in tcp_create_openreq_child() [1] This is caused by a recent change, combined by the fact that TCP cleared num_timeout, num_retrans and sk fields only when a request socket was about to be queued. Under syncookie mode, a temporary request socket is used, and req->num_timeout could contain garbage. Lets clear these three fields sooner, there is really no point trying to defer this and risk other bugs. [1] BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526 CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304 tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526 tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152 tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209 cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline] tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397 ip6_input_finish net/ipv6/ip6_input.c:438 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447 dst_input include/net/dst.h:439 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core net/core/dev.c:4981 [inline] __netif_receive_skb net/core/dev.c:5095 [inline] process_backlog+0x721/0x1410 net/core/dev.c:5906 napi_poll net/core/dev.c:6329 [inline] net_rx_action+0x738/0x1940 net/core/dev.c:6395 __do_softirq+0x4ad/0x858 kernel/softirq.c:293 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052 </IRQ> do_softirq kernel/softirq.c:338 [inline] __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline] ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167 dst_output include/net/dst.h:433 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline] tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470 __sock_release net/socket.c:601 [inline] sock_close+0x156/0x490 net/socket.c:1273 __fput+0x4c9/0xba0 fs/file_table.c:280 ____fput+0x37/0x40 fs/file_table.c:313 task_work_run+0x22e/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop arch/x86/entry/common.c:168 [inline] prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x401d50 Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00 RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50 RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0 R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline] kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160 kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177 kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781 reqsk_alloc include/net/request_sock.h:84 [inline] inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384 cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline] tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397 ip6_input_finish net/ipv6/ip6_input.c:438 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447 dst_input include/net/dst.h:439 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core net/core/dev.c:4981 [inline] __netif_receive_skb net/core/dev.c:5095 [inline] process_backlog+0x721/0x1410 net/core/dev.c:5906 napi_poll net/core/dev.c:6329 [inline] net_rx_action+0x738/0x1940 net/core/dev.c:6395 __do_softirq+0x4ad/0x858 kernel/softirq.c:293 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052 do_softirq kernel/softirq.c:338 [inline] __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline] ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167 dst_output include/net/dst.h:433 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline] tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470 __sock_release net/socket.c:601 [inline] sock_close+0x156/0x490 net/socket.c:1273 __fput+0x4c9/0xba0 fs/file_table.c:280 ____fput+0x37/0x40 fs/file_table.c:313 task_work_run+0x22e/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop arch/x86/entry/common.c:168 [inline] prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19 09:38:38 -07:00
tcp: better retrans tracking for defer-accept For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Elliott Hughes <enh@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-27 23:16:46 +00:00