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2022-05-12tcp: make sure treq->af_specific is initializedEric Dumazet
commit ba5a4fdd63ae0c575707030db0b634b160baddd7 upstream. syzbot complained about a recent change in TCP stack, hitting a NULL pointer [1] tcp request sockets have an af_specific pointer, which was used before the blamed change only for SYNACK generation in non SYNCOOKIE mode. tcp requests sockets momentarily created when third packet coming from client in SYNCOOKIE mode were not using treq->af_specific. Make sure this field is populated, in the same way normal TCP requests sockets do in tcp_conn_request(). [1] TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 3695 Comm: syz-executor864 Not tainted 5.18.0-rc3-syzkaller-00224-g5fd1fe4807f9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tcp_create_openreq_child+0xe16/0x16b0 net/ipv4/tcp_minisocks.c:534 Code: 48 c1 ea 03 80 3c 02 00 0f 85 e5 07 00 00 4c 8b b3 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 07 00 00 48 8b 3c 24 48 89 de 41 ff 56 08 48 RSP: 0018:ffffc90000de0588 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888076490330 RCX: 0000000000000100 RDX: 0000000000000001 RSI: ffffffff87d67ff0 RDI: 0000000000000008 RBP: ffff88806ee1c7f8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d67f00 R11: 0000000000000000 R12: ffff88806ee1bfc0 R13: ffff88801b0e0368 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f517fe58700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcead76960 CR3: 000000006f97b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> tcp_v6_syn_recv_sock+0x199/0x23b0 net/ipv6/tcp_ipv6.c:1267 tcp_get_cookie_sock+0xc9/0x850 net/ipv4/syncookies.c:207 cookie_v6_check+0x15c3/0x2340 net/ipv6/syncookies.c:258 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1131 [inline] tcp_v6_do_rcv+0x1148/0x13b0 net/ipv6/tcp_ipv6.c:1486 tcp_v6_rcv+0x3305/0x3840 net/ipv6/tcp_ipv6.c:1725 ip6_protocol_deliver_rcu+0x2e9/0x1900 net/ipv6/ip6_input.c:422 ip6_input_finish+0x14c/0x2c0 net/ipv6/ip6_input.c:464 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:473 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x27f/0x3b0 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413 napi_poll net/core/dev.c:6480 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6567 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 Fixes: 5b0b9e4c2c89 ("tcp: md5: incorrect tcp_header_len for incoming connections") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net> [fruggeri: Account for backport conflicts from 35b2c3211609 and 6fc8c827dd4f] Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-27tcp: fix race condition when creating child sockets from syncookiesRicardo Dias
[ Upstream commit 01770a166165738a6e05c3d911fb4609cc4eb416 ] When the TCP stack is in SYN flood mode, the server child socket is created from the SYN cookie received in a TCP packet with the ACK flag set. The child socket is created when the server receives the first TCP packet with a valid SYN cookie from the client. Usually, this packet corresponds to the final step of the TCP 3-way handshake, the ACK packet. But is also possible to receive a valid SYN cookie from the first TCP data packet sent by the client, and thus create a child socket from that SYN cookie. Since a client socket is ready to send data as soon as it receives the SYN+ACK packet from the server, the client can send the ACK packet (sent by the TCP stack code), and the first data packet (sent by the userspace program) almost at the same time, and thus the server will equally receive the two TCP packets with valid SYN cookies almost at the same instant. When such event happens, the TCP stack code has a race condition that occurs between the momement a lookup is done to the established connections hashtable to check for the existence of a connection for the same client, and the moment that the child socket is added to the established connections hashtable. As a consequence, this race condition can lead to a situation where we add two child sockets to the established connections hashtable and deliver two sockets to the userspace program to the same client. This patch fixes the race condition by checking if an existing child socket exists for the same client when we are adding the second child socket to the established connections socket. If an existing child socket exists, we drop the packet and discard the second child socket to the same client. Signed-off-by: Ricardo Dias <rdias@singlestore.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201120111133.GA67501@rdias-suse-pc.lan Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25ipv6: tcp: drop silly ICMPv6 packet too big messagesEric Dumazet
commit c7bb4b89033b764eb07db4e060548a6311d801ee upstream. While TCP stack scales reasonably well, there is still one part that can be used to DDOS it. IPv6 Packet too big messages have to lookup/insert a new route, and if abused by attackers, can easily put hosts under high stress, with many cpus contending on a spinlock while one is stuck in fib6_run_gc() ip6_protocol_deliver_rcu() icmpv6_rcv() icmpv6_notify() tcp_v6_err() tcp_v6_mtu_reduced() inet6_csk_update_pmtu() ip6_rt_update_pmtu() __ip6_rt_update_pmtu() ip6_rt_cache_alloc() ip6_dst_alloc() dst_alloc() ip6_dst_gc() fib6_run_gc() spin_lock_bh() ... Some of our servers have been hit by malicious ICMPv6 packets trying to _increase_ the MTU/MSS of TCP flows. We believe these ICMPv6 packets are a result of a bug in one ISP stack, since they were blindly sent back for _every_ (small) packet sent to them. These packets are for one TCP flow: 09:24:36.266491 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240 09:24:36.266509 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240 09:24:36.316688 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240 09:24:36.316704 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240 09:24:36.608151 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240 TCP stack can filter some silly requests : 1) MTU below IPV6_MIN_MTU can be filtered early in tcp_v6_err() 2) tcp_v6_mtu_reduced() can drop requests trying to increase current MSS. This tests happen before the IPv6 routing stack is entered, thus removing the potential contention and route exhaustion. Note that IPv6 stack was performing these checks, but too late (ie : after the route has been added, and after the potential garbage collect war) v2: fix typo caught by Martin, thanks ! v3: exports tcp_mtu_to_mss(), caught by David, thanks ! Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25tcp: annotate data races around tp->mtu_infoEric Dumazet
commit 561022acb1ce62e50f7a8258687a21b84282a4cb upstream. While tp->mtu_info is read while socket is owned, the write sides happen from err handlers (tcp_v[46]_mtu_reduced) which only own the socket spinlock. Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25net: send SYNACK packet with accepted fwmarkAlexander Ovechkin
commit 43b90bfad34bcb81b8a5bc7dc650800f4be1787e upstream. commit e05a90ec9e16 ("net: reflect mark on tcp syn ack packets") fixed IPv4 only. This part is for the IPv6 side. Fixes: e05a90ec9e16 ("net: reflect mark on tcp syn ack packets") Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru> Acked-by: Dmitry Yakunin <zeil@yandex-team.ru> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07ipv6: weaken the v4mapped source checkJakub Kicinski
[ Upstream commit dcc32f4f183ab8479041b23a1525d48233df1d43 ] This reverts commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3. Commit 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") introduced an input check against v4mapped addresses. Use of such addresses on the wire is indeed questionable and not allowed on public Internet. As the commit pointed out https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02 lists potential issues. Unfortunately there are applications which use v4mapped addresses, and breaking them is a clear regression. For example v4mapped addresses (or any semi-valid addresses, really) may be used for uni-direction event streams or packet export. Since the issue which sparked the addition of the check was with TCP and request_socks in particular push the check down to TCPv6 and DCCP. This restores the ability to receive UDPv6 packets with v4mapped address as the source. Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the user-visible changes. Fixes: 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") Reported-by: Sunyi Shao <sunyishao@fb.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-18net: ipv6: add net argument to ip6_dst_lookup_flowSabrina Dubroca
[ Upstream commit c4e85f73afb6384123e5ef1bba3315b2e3ad031e ] This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow, as some modules currently pass a net argument without a socket to ip6_dst_lookup. This is equivalent to commit 343d60aada5a ("ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument"). Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-13tcp: annotate tp->write_seq lockless readsEric Dumazet
There are few places where we fetch tp->write_seq while this field can change from IRQ or other cpu. We need to add READ_ONCE() annotations, and also make sure write sides use corresponding WRITE_ONCE() to avoid store-tearing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13tcp: annotate tp->copied_seq lockless readsEric Dumazet
There are few places where we fetch tp->copied_seq while this field can change from IRQ or other cpu. We need to add READ_ONCE() annotations, and also make sure write sides use corresponding WRITE_ONCE() to avoid store-tearing. Note that tcp_inq_hint() was already using READ_ONCE(tp->copied_seq) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13tcp: annotate tp->rcv_nxt lockless readsEric Dumazet
There are few places where we fetch tp->rcv_nxt while this field can change from IRQ or other cpu. We need to add READ_ONCE() annotations, and also make sure write sides use corresponding WRITE_ONCE() to avoid store-tearing. Note that tcp_inq_hint() was already using READ_ONCE(tp->rcv_nxt) syzbot reported : BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv write to 0xffff888120425770 of 4 bytes by interrupt on cpu 0: tcp_rcv_nxt_update net/ipv4/tcp_input.c:3365 [inline] tcp_queue_rcv+0x180/0x380 net/ipv4/tcp_input.c:4638 tcp_rcv_established+0xbf1/0xf50 net/ipv4/tcp_input.c:5616 tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1542 tcp_v4_rcv+0x1a03/0x1bf0 net/ipv4/tcp_ipv4.c:1923 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208 napi_skb_finish net/core/dev.c:5671 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5704 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 read to 0xffff888120425770 of 4 bytes by task 7254 on cpu 1: tcp_stream_is_readable net/ipv4/tcp.c:480 [inline] tcp_poll+0x204/0x6b0 net/ipv4/tcp.c:554 sock_poll+0xed/0x250 net/socket.c:1256 vfs_poll include/linux/poll.h:90 [inline] ep_item_poll.isra.0+0x90/0x190 fs/eventpoll.c:892 ep_send_events_proc+0x113/0x5c0 fs/eventpoll.c:1749 ep_scan_ready_list.constprop.0+0x189/0x500 fs/eventpoll.c:704 ep_send_events fs/eventpoll.c:1793 [inline] ep_poll+0xe3/0x900 fs/eventpoll.c:1930 do_epoll_wait+0x162/0x180 fs/eventpoll.c:2294 __do_sys_epoll_pwait fs/eventpoll.c:2325 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2311 [inline] __x64_sys_epoll_pwait+0xcd/0x170 fs/eventpoll.c:2311 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7254 Comm: syz-fuzzer Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13tcp: add rcu protection around tp->fastopen_rskEric Dumazet
Both tcp_v4_err() and tcp_v6_err() do the following operations while they do not own the socket lock : fastopen = tp->fastopen_rsk; snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; The problem is that without appropriate barrier, the compiler might reload tp->fastopen_rsk and trigger a NULL deref. request sockets are protected by RCU, we can simply add the missing annotations and barriers to solve the issue. Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27tcp: honor SO_PRIORITY in TIME_WAIT stateEric Dumazet
ctl packets sent on behalf of TIME_WAIT sockets currently have a zero skb->priority, which can cause various problems. In this patch we : - add a tw_priority field in struct inet_timewait_sock. - populate it from sk->sk_priority when a TIME_WAIT is created. - For IPv4, change ip_send_unicast_reply() and its two callers to propagate tw_priority correctly. ip_send_unicast_reply() no longer changes sk->sk_priority. - For IPv6, make sure TIME_WAIT sockets pass their tw_priority field to tcp_v6_send_response() and tcp_v6_send_ack(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27ipv6: tcp: provide sk->sk_priority to ctl packetsEric Dumazet
We can populate skb->priority for some ctl packets instead of always using zero. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27ipv6: add priority parameter to ip6_xmit()Eric Dumazet
Currently, ip6_xmit() sets skb->priority based on sk->sk_priority This is not desirable for TCP since TCP shares the same ctl socket for a given netns. We want to be able to send RST or ACK packets with a non zero skb->priority. This patch has no functional change. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-30tcp: add skb-less helpers to retrieve SYN cookiePetar Penkov
This patch allows generation of a SYN cookie before an SKB has been allocated, as is the case at XDP. Signed-off-by: Petar Penkov <ppenkov@google.com> Reviewed-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-11ipv6: tcp: fix flowlabels reflection for RST packetsEric Dumazet
In 323a53c41292 ("ipv6: tcp: enable flowlabel reflection in some RST packets") and 50a8accf1062 ("ipv6: tcp: send consistent flowlabel in TIME_WAIT state") we took care of IPv6 flowlabel reflections for two cases. This patch takes care of the remaining case, when the RST packet is sent on behalf of a 'full' socket. In Marek use case, this was a socket in TCP_CLOSE state. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Marek Majkowski <marek@cloudflare.com> Tested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08ipv6: elide flowlabel check if no exclusive leases existWillem de Bruijn
Processes can request ipv6 flowlabels with cmsg IPV6_FLOWINFO. If not set, by default an autogenerated flowlabel is selected. Explicit flowlabels require a control operation per label plus a datapath check on every connection (every datagram if unconnected). This is particularly expensive on unconnected sockets multiplexing many flows, such as QUIC. In the common case, where no lease is exclusive, the check can be safely elided, as both lease request and check trivially succeed. Indeed, autoflowlabel does the same even with exclusive leases. Elide the check if no process has requested an exclusive lease. fl6_sock_lookup previously returns either a reference to a lease or NULL to denote failure. Modify to return a real error and update all callers. On return NULL, they can use the label and will elide the atomic_dec in fl6_sock_release. This is an optimization. Robust applications still have to revert to requesting leases if the fast path fails due to an exclusive lease. Changes RFC->v1: - use static_key_false_deferred to rate limit jump label operations - call static_key_deferred_flush to stop timers on exit - move decrement out of RCU context - defer optimization also if opt data is associated with a lease - updated all fp6_sock_lookup callers, not just udp Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01ipv6: icmp: allow flowlabel reflection in echo repliesEric Dumazet
Extend flowlabel_reflect bitmask to allow conditional reflection of incoming flowlabels in echo replies. Note this has precedence against auto flowlabels. Add flowlabel_reflect enum to replace hard coded values. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14ipv4: tcp: fix ACK/RST sent with a transmit delayEric Dumazet
If we want to set a EDT time for the skb we want to send via ip_send_unicast_reply(), we have to pass a new parameter and initialize ipc.sockc.transmit_time with it. This fixes the EDT time for ACK/RST packets sent on behalf of a TIME_WAIT socket. Fixes: a842fe1425cb ("tcp: add optional per socket transmit delay") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-12tcp: add optional per socket transmit delayEric Dumazet
Adding delays to TCP flows is crucial for studying behavior of TCP stacks, including congestion control modules. Linux offers netem module, but it has unpractical constraints : - Need root access to change qdisc - Hard to setup on egress if combined with non trivial qdisc like FQ - Single delay for all flows. EDT (Earliest Departure Time) adoption in TCP stack allows us to enable a per socket delay at a very small cost. Networking tools can now establish thousands of flows, each of them with a different delay, simulating real world conditions. This requires FQ packet scheduler or a EDT-enabled NIC. This patchs adds TCP_TX_DELAY socket option, to set a delay in usec units. unsigned int tx_delay = 10000; /* 10 msec */ setsockopt(fd, SOL_TCP, TCP_TX_DELAY, &tx_delay, sizeof(tx_delay)); Note that FQ packet scheduler limits might need some tweaking : man tc-fq PARAMETERS limit Hard limit on the real queue size. When this limit is reached, new packets are dropped. If the value is lowered, packets are dropped so that the new limit is met. Default is 10000 packets. flow_limit Hard limit on the maximum number of packets queued per flow. Default value is 100. Use of TCP_TX_DELAY option will increase number of skbs in FQ qdisc, so packets would be dropped if any of the previous limit is hit. Use of a jump label makes this support runtime-free, for hosts never using the option. Also note that TSQ (TCP Small Queues) limits are slightly changed with this patch : we need to account that skbs artificially delayed wont stop us providind more skbs to feed the pipe (netem uses skb_orphan_partial() for this purpose, but FQ can not use this trick) Because of that, using big delays might very well trigger old bugs in TSO auto defer logic and/or sndbuf limited detection. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-09ipv6: tcp: send consistent autoflowlabel in TIME_WAIT stateEric Dumazet
In case autoflowlabel is in action, skb_get_hash_flowi6() derives a non zero skb->hash to the flowlabel. If skb->hash is zero, a flow dissection is performed. Since all TCP skbs sent from ESTABLISH state inherit their skb->hash from sk->sk_txhash, we better keep a copy of sk->sk_txhash into the TIME_WAIT socket. After this patch, ACK or RST packets sent on behalf of a TIME_WAIT socket have the flowlabel that was previously used by the flow. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-09ipv6: tcp: fix potential NULL deref in tcp_v6_send_reset()Eric Dumazet
syzbot found a crash in tcp_v6_send_reset() caused by my latest change. Problem is that if an skb has been queued to socket prequeue, skb_dst(skb)->dev can not anymore point to the device. Fortunately in this case the socket pointer is not NULL. A similar issue has been fixed in commit 0f85feae6b71 ("tcp: fix more NULL deref after prequeue changes"), I should have known better. Fixes: 323a53c41292 ("ipv6: tcp: enable flowlabel reflection in some RST packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-05ipv6: tcp: send consistent flowlabel in TIME_WAIT stateEric Dumazet
After commit 1d13a96c74fc ("ipv6: tcp: fix flowlabel value in ACK messages"), we stored in tw_flowlabel the flowlabel, in the case ACK packets needed to be sent on behalf of a TIME_WAIT socket. We can use the same field so that RST packets sent from TIME_WAIT state also use a consistent flowlabel. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florent Fourcot <florent.fourcot@wifirst.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-05ipv6: tcp: enable flowlabel reflection in some RST packetsEric Dumazet
When RST packets are sent because no socket could be found, it makes sense to use flowlabel_reflect sysctl to decide if a reflection of the flowlabel is requested. This extends commit 22b6722bfa59 ("ipv6: Add sysctl for per namespace flow label reflection"), for some TCP RST packets. In order to provide full control of this new feature, flowlabel_reflect becomes a bitmask. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-05net: use indirect calls helpers at early demux stagePaolo Abeni
So that we avoid another indirect call per RX packet, if early demux is enabled. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-05net: use indirect calls helpers for L3 handler hooksPaolo Abeni
So that we avoid another indirect call per RX packet in the common case. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-01tcp: fix tcp_inet6_sk() for 32bit kernelsEric Dumazet
It turns out that struct ipv6_pinfo is not located as we think. inet6_sk_generic() and tcp_inet6_sk() disagree on 32bit kernels by 4-bytes, because struct tcp_sock has 8-bytes alignment, but ipv6_pinfo size is not a multiple of 8. sizeof(struct ipv6_pinfo): 116 (not padded to 8) I actually first coded tcp_inet6_sk() as this patch does, but thought that "container_of(tcp_sk(sk), struct tcp6_sock, tcp)" was cleaner. As Julian told me : Nobody should use tcp6_sock.inet6 directly, it should be accessed via tcp_inet6_sk() or inet6_sk(). This happened when we added the first u64 field in struct tcp_sock. Fixes: 93a77c11ae79 ("tcp: add tcp_inet6_sk() helper") Signed-off-by: Eric Dumazet <edumazet@google.com> Bisected-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2019-03-23tcp: add one skb cache for rxEric Dumazet
Often times, recvmsg() system calls and BH handling for a particular TCP socket are done on different cpus. This means the incoming skb had to be allocated on a cpu, but freed on another. This incurs a high spinlock contention in slab layer for small rpc, but also a high number of cache line ping pongs for larger packets. A full size GRO packet might use 45 page fragments, meaning that up to 45 put_page() can be involved. More over performing the __kfree_skb() in the recvmsg() context adds a latency for user applications, and increase probability of trapping them in backlog processing, since the BH handler might found the socket owned by the user. This patch, combined with the prior one increases the rpc performance by about 10 % on servers with large number of cores. (tcp_rr workload with 10,000 flows and 112 threads reach 9 Mpps instead of 8 Mpps) This also increases single bulk flow performance on 40Gbit+ links, since in this case there are often two cpus working in tandem : - CPU handling the NIC rx interrupts, feeding the receive queue, and (after this patch) freeing the skbs that were consumed. - CPU in recvmsg() system call, essentially 100 % busy copying out data to user space. Having at most one skb in a per-socket cache has very little risk of memory exhaustion, and since it is protected by socket lock, its management is essentially free. Note that if rps/rfs is used, we do not enable this feature, because there is high chance that the same cpu is handling both the recvmsg() system call and the TCP rx path, but that another cpu did the skb allocations in the device driver right before the RPS/RFS logic. To properly handle this case, it seems we would need to record on which cpu skb was allocated, and use a different channel to give skbs back to this cpu. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-19tcp: add tcp_inet6_sk() helperEric Dumazet
TCP ipv6 fast path dereferences a pointer to get to the inet6 part of a tcp socket, but given the fixed memory placement, we can do better and avoid a possible cache line miss. This also reduces register pressure, since we let the compiler know about this memory placement. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-19tcp: do not use ipv6 header for ipv4 flowEric Dumazet
When a dual stack tcp listener accepts an ipv4 flow, it should not attempt to use an ipv6 header or tcp_v6_iif() helper. Fixes: 1397ed35f22d ("ipv6: add flowinfo for tcp6 pkt_options for all cases") Fixes: df3687ffc665 ("ipv6: add the IPV6_FL_F_REFLECT flag to IPV6_FL_A_GET") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-25tcp: clean up SOCK_DEBUG()Yafang Shao
Per discussion with Daniel[1] and Eric[2], these SOCK_DEBUG() calles in TCP are not needed now. We'd better clean up it. [1] https://patchwork.ozlabs.org/patch/1035573/ [2] https://patchwork.ozlabs.org/patch/1040533/ Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-27tcp: Refactor pingpong codeWei Wang
Instead of using pingpong as a single bit information, we refactor the code to treat it as a counter. When interactive session is detected, we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode. This patch is a pure refactor and sets foundation for the next patch. This patch itself does not change any pingpong logic. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-15ipv6: Fix handling of LLA with VRF and sockets bound to VRFDavid Ahern
A recent commit allows sockets bound to a VRF to receive ipv6 link local packets. However, it only works for UDP and worse TCP connection attempts to the LLA with the only listener bound to the VRF just hang where as before the client gets a reset and connection refused. Fix by adjusting ir_iif for LL addresses and packets received through a device enslaved to a VRF. Fixes: 6f12fa775530 ("vrf: mark skb for multicast or link-local as enslaved to VRF") Reported-by: Donald Sharp <sharpd@cumulusnetworks.com> Cc: Mike Manning <mmanning@vyatta.att-mail.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: Convert protocol error handlers from void to intStefano Brivio
We'll need this to handle ICMP errors for tunnels without a sending socket (i.e. FoU and GUE). There, we might have to look up different types of IP tunnels, registered as network protocols, before we get a match, so we want this for the error handlers of IPPROTO_IPIP and IPPROTO_IPV6 in both inet_protos and inet6_protos. These error codes will be used in the next patch. For consistency, return sensible error codes in protocol error handlers whenever handlers can't handle errors because, even if valid, they don't match a protocol or any of its states. This has no effect on existing error handling paths. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-21net/ipv6: Fix linklocal to global address with VRFDavid Ahern
Example setup: host: ip -6 addr add dev eth1 2001:db8:104::4 where eth1 is enslaved to a VRF switch: ip -6 ro add 2001:db8:104::4/128 dev br1 where br1 only has an LLA ping6 2001:db8:104::4 ssh 2001:db8:104::4 (NOTE: UDP works fine if the PKTINFO has the address set to the global address and ifindex is set to the index of eth1 with a destination an LLA). For ICMP, icmp6_iif needs to be updated to check if skb->dev is an L3 master. If it is then return the ifindex from rt6i_idev similar to what is done for loopback. For TCP, restore the original tcp_v6_iif definition which is needed in most places and add a new tcp_v6_iif_l3_slave that considers the l3_slave variability. This latter check is only needed for socket lookups. Fixes: 9ff74384600a ("net: vrf: Handle ipv6 multicast and link-local addresses") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14tcp: verify the checksum of the first data segment in a new connectionFrank van der Linden
commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") introduced an optimization for the handling of child sockets created for a new TCP connection. But this optimization passes any data associated with the last ACK of the connection handshake up the stack without verifying its checksum, because it calls tcp_child_process(), which in turn calls tcp_rcv_state_process() directly. These lower-level processing functions do not do any checksum verification. Insert a tcp_checksum_complete call in the TCP_NEW_SYN_RECEIVE path to fix this. Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Add Maglev hashing scheduler to IPVS, from Inju Song. 2) Lots of new TC subsystem tests from Roman Mashak. 3) Add TCP zero copy receive and fix delayed acks and autotuning with SO_RCVLOWAT, from Eric Dumazet. 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard Brouer. 5) Add ttl inherit support to vxlan, from Hangbin Liu. 6) Properly separate ipv6 routes into their logically independant components. fib6_info for the routing table, and fib6_nh for sets of nexthops, which thus can be shared. From David Ahern. 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP messages from XDP programs. From Nikita V. Shirokov. 8) Lots of long overdue cleanups to the r8169 driver, from Heiner Kallweit. 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau. 10) Add traffic condition monitoring to iwlwifi, from Luca Coelho. 11) Plumb extack down into fib_rules, from Roopa Prabhu. 12) Add Flower classifier offload support to igb, from Vinicius Costa Gomes. 13) Add UDP GSO support, from Willem de Bruijn. 14) Add documentation for eBPF helpers, from Quentin Monnet. 15) Add TLS tx offload to mlx5, from Ilya Lesokhin. 16) Allow applications to be given the number of bytes available to read on a socket via a control message returned from recvmsg(), from Soheil Hassas Yeganeh. 17) Add x86_32 eBPF JIT compiler, from Wang YanQing. 18) Add AF_XDP sockets, with zerocopy support infrastructure as well. From Björn Töpel. 19) Remove indirect load support from all of the BPF JITs and handle these operations in the verifier by translating them into native BPF instead. From Daniel Borkmann. 20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha. 21) Allow XDP programs to do lookups in the main kernel routing tables for forwarding. From David Ahern. 22) Allow drivers to store hardware state into an ELF section of kernel dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy. 23) Various RACK and loss detection improvements in TCP, from Yuchung Cheng. 24) Add TCP SACK compression, from Eric Dumazet. 25) Add User Mode Helper support and basic bpfilter infrastructure, from Alexei Starovoitov. 26) Support ports and protocol values in RTM_GETROUTE, from Roopa Prabhu. 27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard Brouer. 28) Add lots of forwarding selftests, from Petr Machata. 29) Add generic network device failover driver, from Sridhar Samudrala. * ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits) strparser: Add __strp_unpause and use it in ktls. rxrpc: Fix terminal retransmission connection ID to include the channel net: hns3: Optimize PF CMDQ interrupt switching process net: hns3: Fix for VF mailbox receiving unknown message net: hns3: Fix for VF mailbox cannot receiving PF response bnx2x: use the right constant Revert "net: sched: cls: Fix offloading when ingress dev is vxlan" net: dsa: b53: Fix for brcm tag issue in Cygnus SoC enic: fix UDP rss bits netdev-FAQ: clarify DaveM's position for stable backports rtnetlink: validate attributes in do_setlink() mlxsw: Add extack messages for port_{un, }split failures netdevsim: Add extack error message for devlink reload devlink: Add extack to reload and port_{un, }split operations net: metrics: add proper netlink validation ipmr: fix error path when ipmr_new_table fails ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds net: hns3: remove unused hclgevf_cfg_func_mta_filter netfilter: provide udp*_lib_lookup for nf_tproxy qed*: Utilize FW 8.37.2.0 ...
2018-05-31tcp: minor optimization around tcp_hdr() usage in receive pathYafang Shao
This is additional to the commit ea1627c20c34 ("tcp: minor optimizations around tcp_hdr() usage"). At this point, skb->data is same with tcp_hdr() as tcp header has not been pulled yet. So use the less expensive one to get the tcp header. Remove the third parameter of tcp_rcv_established() and put it into the function body. Furthermore, the local variables are listed as a reverse christmas tree :) Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-16proc: introduce proc_create_net{,_data}Christoph Hellwig
Variants of proc_create{,_data} that directly take a struct seq_operations and deal with network namespaces in ->open and ->release. All callers of proc_create + seq_open_net converted over, and seq_{open,release}_net are removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16ipv{4,6}/tcp: simplify procfs registrationChristoph Hellwig
Avoid most of the afinfo indirections and just call the proc helpers directly. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-10tcp: Add mark for TIMEWAIT socketsJon Maxwell
This version has some suggestions by Eric Dumazet: - Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP races. - Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark" statement. - Factorize code as sk_fullsock() check is not necessary. Aidan McGurn from Openwave Mobility systems reported the following bug: "Marked routing is broken on customer deployment. Its effects are large increase in Uplink retransmissions caused by the client never receiving the final ACK to their FINACK - this ACK misses the mark and routes out of the incorrect route." Currently marks are added to sk_buffs for replies when the "fwmark_reflect" sysctl is enabled. But not for TW sockets that had sk->sk_mark set via setsockopt(SO_MARK..). Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location. Then progate this so that the skb gets sent with the correct mark. Do the same for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that netfilter rules are still honored. Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-03-31 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add raw BPF tracepoint API in order to have a BPF program type that can access kernel internal arguments of the tracepoints in their raw form similar to kprobes based BPF programs. This infrastructure also adds a new BPF_RAW_TRACEPOINT_OPEN command to BPF syscall which returns an anon-inode backed fd for the tracepoint object that allows for automatic detach of the BPF program resp. unregistering of the tracepoint probe on fd release, from Alexei. 2) Add new BPF cgroup hooks at bind() and connect() entry in order to allow BPF programs to reject, inspect or modify user space passed struct sockaddr, and as well a hook at post bind time once the port has been allocated. They are used in FB's container management engine for implementing policy, replacing fragile LD_PRELOAD wrapper intercepting bind() and connect() calls that only works in limited scenarios like glibc based apps but not for other runtimes in containerized applications, from Andrey. 3) BPF_F_INGRESS flag support has been added to sockmap programs for their redirect helper call bringing it in line with cls_bpf based programs. Support is added for both variants of sockmap programs, meaning for tx ULP hooks as well as recv skb hooks, from John. 4) Various improvements on BPF side for the nfp driver, besides others this work adds BPF map update and delete helper call support from the datapath, JITing of 32 and 64 bit XADD instructions as well as offload support of bpf_get_prandom_u32() call. Initial implementation of nfp packet cache has been tackled that optimizes memory access (see merge commit for further details), from Jakub and Jiong. 5) Removal of struct bpf_verifier_env argument from the print_bpf_insn() API has been done in order to prepare to use print_bpf_insn() soon out of perf tool directly. This makes the print_bpf_insn() API more generic and pushes the env into private data. bpftool is adjusted as well with the print_bpf_insn() argument removal, from Jiri. 6) Couple of cleanups and prep work for the upcoming BTF (BPF Type Format). The latter will reuse the current BPF verifier log as well, thus bpf_verifier_log() is further generalized, from Martin. 7) For bpf_getsockopt() and bpf_setsockopt() helpers, IPv4 IP_TOS read and write support has been added in similar fashion to existing IPv6 IPV6_TCLASS socket option we already have, from Nikita. 8) Fixes in recent sockmap scatterlist API usage, which did not use sg_init_table() for initialization thus triggering a BUG_ON() in scatterlist API when CONFIG_DEBUG_SG was enabled. This adds and uses a small helper sg_init_marker() to properly handle the affected cases, from Prashant. 9) Let the BPF core follow IDR code convention and therefore use the idr_preload() and idr_preload_end() helpers, which would also help idr_alloc_cyclic() under GFP_ATOMIC to better succeed under memory pressure, from Shaohua. 10) Last but not least, a spelling fix in an error message for the BPF cookie UID helper under BPF sample code, from Colin. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31bpf: Hooks for sys_connectAndrey Ignatov
== The problem == See description of the problem in the initial patch of this patch set. == The solution == The patch provides much more reliable in-kernel solution for the 2nd part of the problem: making outgoing connecttion from desired IP. It adds new attach types `BPF_CGROUP_INET4_CONNECT` and `BPF_CGROUP_INET6_CONNECT` for program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that can be used to override both source and destination of a connection at connect(2) time. Local end of connection can be bound to desired IP using newly introduced BPF-helper `bpf_bind()`. It allows to bind to only IP though, and doesn't support binding to port, i.e. leverages `IP_BIND_ADDRESS_NO_PORT` socket option. There are two reasons for this: * looking for a free port is expensive and can affect performance significantly; * there is no use-case for port. As for remote end (`struct sockaddr *` passed by user), both parts of it can be overridden, remote IP and remote port. It's useful if an application inside cgroup wants to connect to another application inside same cgroup or to itself, but knows nothing about IP assigned to the cgroup. Support is added for IPv4 and IPv6, for TCP and UDP. IPv4 and IPv6 have separate attach types for same reason as sys_bind hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound. == Implementation notes == The patch introduces new field in `struct proto`: `pre_connect` that is a pointer to a function with same signature as `connect` but is called before it. The reason is in some cases BPF hooks should be called way before control is passed to `sk->sk_prot->connect`. Specifically `inet_dgram_connect` autobinds socket before calling `sk->sk_prot->connect` and there is no way to call `bpf_bind()` from hooks from e.g. `ip4_datagram_connect` or `ip6_datagram_connect` since it'd cause double-bind. On the other hand `proto.pre_connect` provides a flexible way to add BPF hooks for connect only for necessary `proto` and call them at desired time before `connect`. Since `bpf_bind()` is allowed to bind only to IP and autobind in `inet_dgram_connect` binds only port there is no chance of double-bind. bpf_bind() sets `force_bind_address_no_port` to bind to only IP despite of value of `bind_address_no_port` socket field. bpf_bind() sets `with_lock` to `false` when calling to __inet_bind() and __inet6_bind() since all call-sites, where bpf_bind() is called, already hold socket lock. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-19net: Convert tcpv6_net_opsKirill Tkhai
These pernet_operations create and destroy net::ipv6.tcp_sk socket, which is used in tcp_v6_send_response() only. It looks like foreign pernet_operations don't want to set ipv6 connection inside destroyed net, so this socket may be created in destroyed in parallel with anything else. inet_twsk_purge() is also safe for that, as described in patch for tcp_sk_ops. So, it's possible to mark them as async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-14tcp: try to keep packet if SYN_RCV race is lostEric Dumazet
배석진 reported that in some situations, packets for a given 5-tuple end up being processed by different CPUS. This involves RPS, and fragmentation. 배석진 is seeing packet drops when a SYN_RECV request socket is moved into ESTABLISH state. Other states are protected by socket lock. This is caused by a CPU losing the race, and simply not caring enough. Since this seems to occur frequently, we can do better and perform a second lookup. Note that all needed memory barriers are already in the existing code, thanks to the spin_lock()/spin_unlock() pair in inet_ehash_insert() and reqsk_put(). The second lookup must find the new socket, unless it has already been accepted and closed by another cpu. Note that the fragmentation could be avoided in the first place by use of a correct TCP MSS option in the SYN{ACK} packet, but this does not mean we can not be more robust. Many thanks to 배석진 for a very detailed analysis. Reported-by: 배석진 <soukjin.bae@samsung.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-07tcp: tracepoint: only call trace_tcp_send_reset with full socketSong Liu
tracepoint tcp_send_reset requires a full socket to work. However, it may be called when in TCP_TIME_WAIT: case TCP_TW_RST: tcp_v6_send_reset(sk, skb); inet_twsk_deschedule_put(inet_twsk(sk)); goto discard_it; To avoid this problem, this patch checks the socket with sk_fullsock() before calling trace_tcp_send_reset(). Fixes: c24b14c46bb8 ("tcp: add tracepoint trace_tcp_send_reset") Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>