summaryrefslogtreecommitdiffstats
path: root/include/net/inet_hashtables.h
Commit message (Collapse)AuthorAgeFilesLines
* tcp: Remove dead code and fields for bhash2.Kuniyuki Iwashima2023-12-221-4/+0
| | | | | | | | | | | | Now all sockets including TIME_WAIT are linked to bhash2 using sock_common.skc_bind_node. We no longer use inet_bind2_bucket.deathrow, sock.sk_bind2_node, and inet_timewait_sock.tw_bind2_node. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Unlink sk from bhash.Kuniyuki Iwashima2023-12-221-1/+0
| | | | | | | | | | | Now we do not use tb->owners and can unlink sockets from bhash. sk_bind_node/tw_bind_node are available for bhash2 and will be used in the following patch. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Link bhash2 to bhash.Kuniyuki Iwashima2023-12-221-1/+3
| | | | | | | | | | | | | | | | | | | bhash2 added a new member sk_bind2_node in struct sock to link sockets to bhash2 in addition to bhash. bhash is still needed to search conflicting sockets efficiently from a port for the wildcard address. However, bhash itself need not have sockets. If we link each bhash2 bucket to the corresponding bhash bucket, we can iterate the same set of the sockets from bhash2 via bhash. This patch links bhash2 to bhash only, and the actual use will be in the later patches. Finally, we will remove sk_bind2_node. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Save address type in inet_bind2_bucket.Kuniyuki Iwashima2023-12-221-0/+1
| | | | | | | | | | | | inet_bind2_bucket_addr_match() and inet_bind2_bucket_match_addr_any() are called for each bhash2 bucket to check conflicts. Thus, we call ipv6_addr_any() and ipv6_addr_v4mapped() over and over during bind(). Let's avoid calling them by saving the address type in inet_bind2_bucket. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Save v4 address as v4-mapped-v6 in inet_bind2_bucket.v6_rcv_saddr.Kuniyuki Iwashima2023-12-221-7/+4
| | | | | | | | | | | | | | | | | | | In bhash2, IPv4/IPv6 addresses are saved in two union members, which complicate address checks in inet_bind2_bucket_addr_match() and inet_bind2_bucket_match_addr_any() considering uninitialised memory and v4-mapped-v6 conflicts. Let's simplify that by saving IPv4 address as v4-mapped-v6 address and defining tb2.rcv_saddr as tb2.v6_rcv_saddr.s6_addr32[3]. Then, we can compare v6 address as is, and after checking v4-mapped-v6, we can compare v4 address easily. Also, we can remove tb2->family. Note these functions will be further refactored in the next patch. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Fix slab-out-of-bounds in inet[6]_steal_sockLorenz Bauer2023-08-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | Kumar reported a KASAN splat in tcp_v6_rcv: bash-5.2# ./test_progs -t btf_skc_cls_ingress ... [ 51.810085] BUG: KASAN: slab-out-of-bounds in tcp_v6_rcv+0x2d7d/0x3440 [ 51.810458] Read of size 2 at addr ffff8881053f038c by task test_progs/226 The problem is that inet[6]_steal_sock accesses sk->sk_protocol without accounting for request or timewait sockets. To fix this we can't just check sock_common->skc_reuseport since that flag is present on timewait sockets. Instead, add a fullsock check to avoid the out of bands access of sk_protocol. Fixes: 9c02bec95954 ("bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign") Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230815-bpf-next-v2-1-95126eaa4c1b@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* tcp/dccp: cache line align inet_hashinfoEric Dumazet2023-08-041-1/+1
| | | | | | | | | | | | | | | | | | I have seen tcp_hashinfo starting at a non optimal location, forcing input handlers to pull two cache lines instead of one, and sharing a cache line that was dirtied more than necessary: ffffffff83680600 b tcp_orphan_timer ffffffff83680628 b tcp_orphan_cache ffffffff8368062c b tcp_enable_tx_delay.__tcp_tx_delay_enabled ffffffff83680630 B tcp_hashinfo ffffffff83680680 b tcp_cong_list_lock After this patch, ehash, ehash_locks, ehash_mask and ehash_locks_mask are located in a read-only cache line. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assignLorenz Bauer2023-07-251-2/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the bpf_sk_assign helper in tc BPF context refuses SO_REUSEPORT sockets. This means we can't use the helper to steer traffic to Envoy, which configures SO_REUSEPORT on its sockets. In turn, we're blocked from removing TPROXY from our setup. The reason that bpf_sk_assign refuses such sockets is that the bpf_sk_lookup helpers don't execute SK_REUSEPORT programs. Instead, one of the reuseport sockets is selected by hash. This could cause dispatch to the "wrong" socket: sk = bpf_sk_lookup_tcp(...) // select SO_REUSEPORT by hash bpf_sk_assign(skb, sk) // SK_REUSEPORT wasn't executed Fixing this isn't as simple as invoking SK_REUSEPORT from the lookup helpers unfortunately. In the tc context, L2 headers are at the start of the skb, while SK_REUSEPORT expects L3 headers instead. Instead, we execute the SK_REUSEPORT program when the assigned socket is pulled out of the skb, further up the stack. This creates some trickiness with regards to refcounting as bpf_sk_assign will put both refcounted and RCU freed sockets in skb->sk. reuseport sockets are RCU freed. We can infer that the sk_assigned socket is RCU freed if the reuseport lookup succeeds, but convincing yourself of this fact isn't straight forward. Therefore we defensively check refcounting on the sk_assign sock even though it's probably not required in practice. Fixes: 8e368dc72e86 ("bpf: Fix use of sk->sk_reuseport from sk_assign") Fixes: cf7fbe660f2d ("bpf: Add socket assign support") Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Joe Stringer <joe@cilium.io> Link: https://lore.kernel.org/bpf/CACAyw98+qycmpQzKupquhkxbvWK4OFyDuuLMBNROnfWMZxUWeA@mail.gmail.com/ Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-7-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* net: remove duplicate sk_lookup helpersLorenz Bauer2023-07-251-0/+7
| | | | | | | | | | Now that inet[6]_lookup_reuseport are parameterised on the ehashfn we can remove two sk_lookup helpers. Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-6-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* net: remove duplicate reuseport_lookup functionsLorenz Bauer2023-07-251-5/+10
| | | | | | | | | | | | | | | | | | | | There are currently four copies of reuseport_lookup: one each for (TCP, UDP)x(IPv4, IPv6). This forces us to duplicate all callers of those functions as well. This is already the case for sk_lookup helpers (inet,inet6,udp4,udp6)_lookup_run_bpf. There are two differences between the reuseport_lookup helpers: 1. They call different hash functions depending on protocol 2. UDP reuseport_lookup checks that sk_state != TCP_ESTABLISHED Move the check for sk_state into the caller and use the INDIRECT_CALL infrastructure to cut down the helpers to one per IP version. Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-4-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* net: export inet_lookup_reuseport and inet6_lookup_reuseportLorenz Bauer2023-07-251-0/+5
| | | | | | | | | | | | | Rename the existing reuseport helpers for IPv4 and IPv6 so that they can be invoked in the follow up commit. Export them so that building DCCP and IPv6 as a module works. No change in functionality. Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-3-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* tcp: Add TIME_WAIT sockets in bhash2.Kuniyuki Iwashima2022-12-301-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jiri Slaby reported regression of bind() with a simple repro. [0] The repro creates a TIME_WAIT socket and tries to bind() a new socket with the same local address and port. Before commit 28044fc1d495 ("net: Add a bhash2 table hashed by port and address"), the bind() failed with -EADDRINUSE, but now it succeeds. The cited commit should have put TIME_WAIT sockets into bhash2; otherwise, inet_bhash2_conflict() misses TIME_WAIT sockets when validating bind() requests if the address is not a wildcard one. The straight option is to move sk_bind2_node from struct sock to struct sock_common to add twsk to bhash2 as implemented as RFC. [1] However, the binary layout change in the struct sock could affect performances moving hot fields on different cachelines. To avoid that, we add another TIME_WAIT list in inet_bind2_bucket and check it while validating bind(). [0]: https://lore.kernel.org/netdev/6b971a4e-c7d8-411e-1f92-fda29b5b2fb9@kernel.org/ [1]: https://lore.kernel.org/netdev/20221221151258.25748-2-kuniyu@amazon.com/ Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") Reported-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp/tcp: Fixup bhash2 bucket when connect() fails.Kuniyuki Iwashima2022-11-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a socket bound to a wildcard address fails to connect(), we only reset saddr and keep the port. Then, we have to fix up the bhash2 bucket; otherwise, the bucket has an inconsistent address in the list. Also, listen() for such a socket will fire the WARN_ON() in inet_csk_get_port(). [0] Note that when a system runs out of memory, we give up fixing the bucket and unlink sk from bhash and bhash2 by inet_put_port(). [0]: WARNING: CPU: 0 PID: 207 at net/ipv4/inet_connection_sock.c:548 inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) Modules linked in: CPU: 0 PID: 207 Comm: bhash2_prev_rep Not tainted 6.1.0-rc3-00799-gc8421681c845 #63 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014 RIP: 0010:inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) Code: 74 a7 eb 93 48 8b 54 24 18 0f b7 cb 4c 89 e6 4c 89 ff e8 48 b2 ff ff 49 8b 87 18 04 00 00 e9 32 ff ff ff 0f 0b e9 34 ff ff ff <0f> 0b e9 42 ff ff ff 41 8b 7f 50 41 8b 4f 54 89 fe 81 f6 00 00 ff RSP: 0018:ffffc900003d7e50 EFLAGS: 00010202 RAX: ffff8881047fb500 RBX: 0000000000004e20 RCX: 0000000000000000 RDX: 000000000000000a RSI: 00000000fffffe00 RDI: 00000000ffffffff RBP: ffffffff8324dc00 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000004e20 R15: ffff8881054e1280 FS: 00007f8ac04dc740(0000) GS:ffff88842fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001540 CR3: 00000001055fa003 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> inet_csk_listen_start (net/ipv4/inet_connection_sock.c:1205) inet_listen (net/ipv4/af_inet.c:228) __sys_listen (net/socket.c:1810) __x64_sys_listen (net/socket.c:1819 net/socket.c:1817 net/socket.c:1817) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) RIP: 0033:0x7f8ac051de5d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 93 af 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc1c177248 EFLAGS: 00000206 ORIG_RAX: 0000000000000032 RAX: ffffffffffffffda RBX: 0000000020001550 RCX: 00007f8ac051de5d RDX: ffffffffffffff80 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007ffc1c177270 R08: 0000000000000018 R09: 0000000000000007 R10: 0000000020001540 R11: 0000000000000206 R12: 00007ffc1c177388 R13: 0000000000401169 R14: 0000000000403e18 R15: 00007f8ac0723000 </TASK> Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* dccp/tcp: Update saddr under bhash's lock.Kuniyuki Iwashima2022-11-221-1/+1
| | | | | | | | | | | | | | | | When we call connect() for a socket bound to a wildcard address, we update saddr locklessly. However, it could result in a data race; another thread iterating over bhash might see a corrupted address. Let's update saddr under the bhash bucket's lock. Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: Fix incorrect address comparison when searching for a bind2 bucketMartin KaFai Lau2022-09-281-0/+3
| | | | | | | | | | | | | | | | | | | | | The v6_rcv_saddr and rcv_saddr are inside a union in the 'struct inet_bind2_bucket'. When searching a bucket by following the bhash2 hashtable chain, eg. inet_bind2_bucket_match, it is only using the sk->sk_family and there is no way to check if the inet_bind2_bucket has a v6 or v4 address in the union. This leads to an uninit-value KMSAN report in [0] and also potentially incorrect matches. This patch fixes it by adding a family member to the inet_bind2_bucket and then tests 'sk->sk_family != tb->family' before matching the sk's address to the tb's address. Cc: Joanne Koong <joannelkoong@gmail.com> Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Tested-by: Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/r/20220927002544.3381205-1-kafai@fb.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: Introduce optional per-netns ehash.Kuniyuki Iwashima2022-09-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The more sockets we have in the hash table, the longer we spend looking up the socket. While running a number of small workloads on the same host, they penalise each other and cause performance degradation. The root cause might be a single workload that consumes much more resources than the others. It often happens on a cloud service where different workloads share the same computing resource. On EC2 c5.24xlarge instance (196 GiB memory and 524288 (1Mi / 2) ehash entries), after running iperf3 in different netns, creating 24Mi sockets without data transfer in the root netns causes about 10% performance regression for the iperf3's connection. thash_entries sockets length Gbps 524288 1 1 50.7 24Mi 48 45.1 It is basically related to the length of the list of each hash bucket. For testing purposes to see how performance drops along the length, I set 131072 (1Mi / 8) to thash_entries, and here's the result. thash_entries sockets length Gbps 131072 1 1 50.7 1Mi 8 49.9 2Mi 16 48.9 4Mi 32 47.3 8Mi 64 44.6 16Mi 128 40.6 24Mi 192 36.3 32Mi 256 32.5 40Mi 320 27.0 48Mi 384 25.0 To resolve the socket lookup degradation, we introduce an optional per-netns hash table for TCP, but it's just ehash, and we still share the global bhash, bhash2 and lhash2. With a smaller ehash, we can look up non-listener sockets faster and isolate such noisy neighbours. In addition, we can reduce lock contention. We can control the ehash size by a new sysctl knob. However, depending on workloads, it will require very sensitive tuning, so we disable the feature by default (net.ipv4.tcp_child_ehash_entries == 0). Moreover, we can fall back to using the global ehash in case we fail to allocate enough memory for a new ehash. The maximum size is 16Mi, which is large enough that even if we have 48Mi sockets, the average list length is 3, and regression would be less than 1%. We can check the current ehash size by another read-only sysctl knob, net.ipv4.tcp_ehash_entries. A negative value means the netns shares the global ehash (per-netns ehash is disabled or failed to allocate memory). # dmesg | cut -d ' ' -f 5- | grep "established hash" TCP established hash table entries: 524288 (order: 10, 4194304 bytes, vmalloc hugepage) # sysctl net.ipv4.tcp_ehash_entries net.ipv4.tcp_ehash_entries = 524288 # can be changed by thash_entries # sysctl net.ipv4.tcp_child_ehash_entries net.ipv4.tcp_child_ehash_entries = 0 # disabled by default # ip netns add test1 # ip netns exec test1 sysctl net.ipv4.tcp_ehash_entries net.ipv4.tcp_ehash_entries = -524288 # share the global ehash # sysctl -w net.ipv4.tcp_child_ehash_entries=100 net.ipv4.tcp_child_ehash_entries = 100 # ip netns add test2 # ip netns exec test2 sysctl net.ipv4.tcp_ehash_entries net.ipv4.tcp_ehash_entries = 128 # own a per-netns ehash with 2^n buckets When more than two processes in the same netns create per-netns ehash concurrently with different sizes, we need to guarantee the size in one of the following ways: 1) Share the global ehash and create per-netns ehash First, unshare() with tcp_child_ehash_entries==0. It creates dedicated netns sysctl knobs where we can safely change tcp_child_ehash_entries and clone()/unshare() to create a per-netns ehash. 2) Control write on sysctl by BPF We can use BPF_PROG_TYPE_CGROUP_SYSCTL to allow/deny read/write on sysctl knobs. Note that the global ehash allocated at the boot time is spread over available NUMA nodes, but inet_pernet_hashinfo_alloc() will allocate pages for each per-netns ehash depending on the current process's NUMA policy. By default, the allocation is done in the local node only, so the per-netns hash table could fully reside on a random node. Thus, depending on the NUMA policy the netns is created with and the CPU the current thread is running on, we could see some performance differences for highly optimised networking applications. Note also that the default values of two sysctl knobs depend on the ehash size and should be tuned carefully: tcp_max_tw_buckets : tcp_child_ehash_entries / 2 tcp_max_syn_backlog : max(128, tcp_child_ehash_entries / 128) As a bonus, we can dismantle netns faster. Currently, while destroying netns, we call inet_twsk_purge(), which walks through the global ehash. It can be potentially big because it can have many sockets other than TIME_WAIT in all netns. Splitting ehash changes that situation, where it's only necessary for inet_twsk_purge() to clean up TIME_WAIT sockets in each netns. With regard to this, we do not free the per-netns ehash in inet_twsk_kill() to avoid UAF while iterating the per-netns ehash in inet_twsk_purge(). Instead, we do it in tcp_sk_exit_batch() after calling tcp_twsk_purge() to keep it protocol-family-independent. In the future, we could optimise ehash lookup/iteration further by removing netns comparison for the per-netns ehash. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: Set NULL to sk->sk_prot->h.hashinfo.Kuniyuki Iwashima2022-09-201-0/+10
| | | | | | | | | | | | | | | | | We will soon introduce an optional per-netns ehash. This means we cannot use the global sk->sk_prot->h.hashinfo to fetch a TCP hashinfo. Instead, set NULL to sk->sk_prot->h.hashinfo for TCP and get a proper hashinfo from net->ipv4.tcp_death_row.hashinfo. Note that we need not use sk->sk_prot->h.hashinfo if DCCP is disabled. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: Add a bhash2 table hashed by port and addressJoanne Koong2022-08-241-2/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current bind hashtable (bhash) is hashed by port only. In the socket bind path, we have to check for bind conflicts by traversing the specified port's inet_bind_bucket while holding the hashbucket's spinlock (see inet_csk_get_port() and inet_csk_bind_conflict()). In instances where there are tons of sockets hashed to the same port at different addresses, the bind conflict check is time-intensive and can cause softirq cpu lockups, as well as stops new tcp connections since __inet_inherit_port() also contests for the spinlock. This patch adds a second bind table, bhash2, that hashes by port and sk->sk_rcv_saddr (ipv4) and sk->sk_v6_rcv_saddr (ipv6). Searching the bhash2 table leads to significantly faster conflict resolution and less time holding the hashbucket spinlock. Please note a few things: * There can be the case where the a socket's address changes after it has been bound. There are two cases where this happens: 1) The case where there is a bind() call on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6) and then a connect() call. The kernel will assign the socket an address when it handles the connect() 2) In inet_sk_reselect_saddr(), which is called when rebuilding the sk header and a few pre-conditions are met (eg rerouting fails). In these two cases, we need to update the bhash2 table by removing the entry for the old address, and add a new entry reflecting the updated address. * The bhash2 table must have its own lock, even though concurrent accesses on the same port are protected by the bhash lock. Bhash2 must have its own lock to protect against cases where sockets on different ports hash to different bhash hashbuckets but to the same bhash2 hashbucket. This brings up a few stipulations: 1) When acquiring both the bhash and the bhash2 lock, the bhash2 lock will always be acquired after the bhash lock and released before the bhash lock is released. 2) There are no nested bhash2 hashbucket locks. A bhash2 lock is always acquired+released before another bhash2 lock is acquired+released. * The bhash table cannot be superseded by the bhash2 table because for bind requests on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6), every socket bound to that port must be checked for a potential conflict. The bhash table is the only source of port->socket associations. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: allow unbound socket for packets in VRF when tcp_l3mdev_accept setMike Manning2022-07-291-16/+3
| | | | | | | | | | | | | | | | | | | | The commit 3c82a21f4320 ("net: allow binding socket in a VRF when there's an unbound socket") changed the inet socket lookup to avoid packets in a VRF from matching an unbound socket. This is to ensure the necessary isolation between the default and other VRFs for routing and forwarding. VRF-unaware processes running in the default VRF cannot access another VRF and have to be run with 'ip vrf exec <vrf>'. This is to be expected with tcp_l3mdev_accept disabled, but could be reallowed when this sysctl option is enabled. So instead of directly checking dif and sdif in inet[6]_match, here call inet_sk_bound_dev_eq(). This allows a match on unbound socket for non-zero sdif i.e. for packets in a VRF, if tcp_l3mdev_accept is enabled. Fixes: 3c82a21f4320 ("net: allow binding socket in a VRF when there's an unbound socket") Signed-off-by: Mike Manning <mvrmanning@gmail.com> Link: https://lore.kernel.org/netdev/a54c149aed38fded2d3b5fdb1a6c89e36a083b74.camel@lasnet.de/ Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Fix data-races around sysctl_tcp_l3mdev_accept.Kuniyuki Iwashima2022-07-151-1/+1
| | | | | | | | | While reading sysctl_tcp_l3mdev_accept, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 6dd9a14e92e5 ("net: Allow accepted sockets to be bound to l3mdev domain") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert "net: Add a second bind table hashed by port and address"Joanne Koong2022-06-161-67/+1
| | | | | | | | | | | | | | | | | | | | | | | | This reverts: commit d5a42de8bdbe ("net: Add a second bind table hashed by port and address") commit 538aaf9b2383 ("selftests: Add test for timing a bind request to a port with a populated bhash entry") Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/ There are a few things that need to be fixed here: * Updating bhash2 in cases where the socket's rcv saddr changes * Adding bhash2 hashbucket locks Links to syzbot reports: https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/ https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/ Fixes: d5a42de8bdbe ("net: Add a second bind table hashed by port and address") Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: Add a second bind table hashed by port and addressJoanne Koong2022-05-201-1/+67
| | | | | | | | | | | | | | | | | | | | | We currently have one tcp bind table (bhash) which hashes by port number only. In the socket bind path, we check for bind conflicts by traversing the specified port's inet_bind2_bucket while holding the bucket's spinlock (see inet_csk_get_port() and inet_csk_bind_conflict()). In instances where there are tons of sockets hashed to the same port at different addresses, checking for a bind conflict is time-intensive and can cause softirq cpu lockups, as well as stops new tcp connections since __inet_inherit_port() also contests for the spinlock. This patch proposes adding a second bind table, bhash2, that hashes by port and ip address. Searching the bhash2 table leads to significantly faster conflict resolution and less time holding the spinlock. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* inet: rename INET_MATCH()Eric Dumazet2022-05-161-1/+1
| | | | | | | | | | | This is no longer a macro, but an inlined function. INET_MATCH() -> inet_match() Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Olivier Hartkopp <socketcan@hartkopp.net> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add READ_ONCE(sk->sk_bound_dev_if) in INET_MATCH()Eric Dumazet2022-05-131-19/+16
| | | | | | | | | | | | | | | | | | | | INET_MATCH() runs without holding a lock on the socket. We probably need to annotate most reads. This patch makes INET_MATCH() an inline function to ease our changes. v2: We remove the 32bit version of it, as modern compilers should generate the same code really, no need to try to be smarter. Also make 'struct net *net' the first argument. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: inet: Retire port only listening_hashMartin KaFai Lau2022-05-121-40/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The listen sk is currently stored in two hash tables, listening_hash (hashed by port) and lhash2 (hashed by port and address). After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), the TCP-SYN lookup fast path does not use listening_hash. The commit 05c0b35709c5 ("tcp: seq_file: Replace listening_hash with lhash2") also moved the seq_file (/proc/net/tcp) iteration usage from listening_hash to lhash2. There are still a few listening_hash usages left. One of them is inet_reuseport_add_sock() which uses the listening_hash to search a listen sk during the listen() system call. This turns out to be very slow on use cases that listen on many different VIPs at a popular port (e.g. 443). [ On top of the slowness in adding to the tail in the IPv6 case ]. The latter patch has a selftest to demonstrate this case. This patch takes this chance to move all remaining listening_hash usages to lhash2 and then retire listening_hash. Since most changes need to be done together, it is hard to cut the listening_hash to lhash2 switch into small patches. The changes in this patch is highlighted here for the review purpose. 1. Because of the listening_hash removal, lhash2 can use the sk->sk_nulls_node instead of the icsk->icsk_listen_portaddr_node. This will also keep the sk_unhashed() check to work as is after stop adding sk to listening_hash. The union is removed from inet_listen_hashbucket because only nulls_head is needed. 2. icsk->icsk_listen_portaddr_node and its helpers are removed. 3. The current lhash2 users needs to iterate with sk_nulls_node instead of icsk_listen_portaddr_node. One case is in the inet[6]_lhash2_lookup(). Another case is the seq_file iterator in tcp_ipv4.c. One thing to note is sk_nulls_next() is needed because the old inet_lhash2_for_each_icsk_continue() does a "next" first before iterating. 4. Move the remaining listening_hash usage to lhash2 inet_reuseport_add_sock() which this series is trying to improve. inet_diag.c and mptcp_diag.c are the final two remaining use cases and is moved to lhash2 now also. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: inet: Remove count from inet_listen_hashbucketMartin KaFai Lau2022-05-121-1/+0
| | | | | | | | | | After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), the count is no longer used. This patch removes it. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* secure_seq: use the 64 bits of the siphash for port offset calculationWilly Tarreau2022-05-041-1/+1
| | | | | | | | | | | | | | | | | | SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit 7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output remained truncated to 32-bit only. In order to exploit more bits from the hash, let's make the functions return the full 64-bit of siphash_3u32(). We also make sure the port offset calculation in __inet_hash_connect() remains done on 32-bit to avoid the need for div_u64_rem() and an extra cost on 32-bit systems. Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Moshe Kol <moshe.kol@mail.huji.ac.il> Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il> Cc: Amit Klein <aksecurity@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: seq_file: Replace listening_hash with lhash2Martin KaFai Lau2021-07-231-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the tcp seq_file iteration on listeners from the port only listening_hash to the port+addr lhash2. When iterating from the bpf iter, the next patch will need to lock the socket such that the bpf iter can call setsockopt (e.g. to change the TCP_CONGESTION). To avoid locking the bucket and then locking the sock, the bpf iter will first batch some sockets from the same bucket and then unlock the bucket. If the bucket size is small (which usually is), it is easier to batch the whole bucket such that it is less likely to miss a setsockopt on a socket due to changes in the bucket. However, the port only listening_hash could have many listeners hashed to a bucket (e.g. many individual VIP(s):443 and also multiple by the number of SO_REUSEPORT). We have seen bucket size in tens of thousands range. Also, the chance of having changes in some popular port buckets (e.g. 443) is also high. The port+addr lhash2 was introduced to solve this large listener bucket issue. Also, the listening_hash usage has already been replaced with lhash2 in the fast path inet[6]_lookup_listener(). This patch follows the same direction on moving to lhash2 and iterates the lhash2 instead of listening_hash. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210701200606.1035783-1-kafai@fb.com
* tcp: fix race condition when creating child sockets from syncookiesRicardo Dias2020-11-231-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dccp: Fix possible memleak in dccp_init and dccp_finiWang Hai2020-06-091-0/+6
| | | | | | | | | | | | | | | | There are some memory leaks in dccp_init() and dccp_fini(). In dccp_fini() and the error handling path in dccp_init(), free lhash2 is missing. Add inet_hashinfo2_free_mod() to do it. If inet_hashinfo2_init_mod() failed in dccp_init(), percpu_counter_destroy() should be called to destroy dccp_orphan_count. It need to goto out_free_percpu when inet_hashinfo2_init_mod() failed. Fixes: c92c81df93df ("net: dccp: fix kernel crash on module load") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Track socket refcounts in skb_steal_sock()Joe Stringer2020-03-301-2/+1
| | | | | | | | | | | Refactor the UDP/TCP handlers slightly to allow skb_steal_sock() to make the determination of whether the socket is reference counted in the case where it is prefetched by earlier logic such as early_demux. Signed-off-by: Joe Stringer <joe@wand.net.nz> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200329225342.16317-3-joe@wand.net.nz
* tcp/dccp: fix possible race __inet_lookup_established()Eric Dumazet2019-12-131-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | Michal Kubecek and Firo Yang did a very nice analysis of crashes happening in __inet_lookup_established(). Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN (via a close()/socket()/listen() cycle) without a RCU grace period, I should not have changed listeners linkage in their hash table. They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt), so that a lookup can detect a socket in a hash list was moved in another one. Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix"), we have to add hlist_nulls_add_tail_rcu() helper. Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Michal Kubecek <mkubecek@suse.cz> Reported-by: Firo Yang <firo.yang@suse.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/ Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-5/+1
| | | | | | | | | | | | | | | | | | | | | 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>
* net: dccp: fix kernel crash on module loadPeter Oskolkov2018-12-241-0/+1
| | | | | | | | | | | | | | | | | | | | Patch eedbbb0d98b2 "net: dccp: initialize (addr,port) ..." added calling to inet_hashinfo2_init() from dccp_init(). However, inet_hashinfo2_init() is marked as __init(), and thus the kernel panics when dccp is loaded as module. Removing __init() tag from inet_hashinfo2_init() is not feasible because it calls into __init functions in mm. This patch adds inet_hashinfo2_init_mod() function that can be called after the init phase is done; changes dccp_init() to call the new function; un-marks inet_hashinfo2_init() as exported. Fixes: eedbbb0d98b2 ("net: dccp: initialize (addr,port) ...") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ensure unbound stream socket to be chosen when not in a VRFMike Manning2018-11-071-0/+11
| | | | | | | | | | | | | | | | | The commit a04a480d4392 ("net: Require exact match for TCP socket lookups if dif is l3mdev") only ensures that the correct socket is selected for packets in a VRF. However, there is no guarantee that the unbound socket will be selected for packets when not in a VRF. By checking for a device match in compute_score() also for the case when there is no bound device and attaching a score to this, the unbound socket is selected. And if a failure is returned when there is no device match, this ensures that bound sockets are never selected, even if there is no unbound socket. Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: allow binding socket in a VRF when there's an unbound socketRobert Shearman2018-11-071-7/+6
| | | | | | | | | | | | | | | | | | | Change the inet socket lookup to avoid packets arriving on a device enslaved to an l3mdev from matching unbound sockets by removing the wildcard for non sk_bound_dev_if and instead relying on check against the secondary device index, which will be 0 when the input device is not enslaved to an l3mdev and so match against an unbound socket and not match when the input device is enslaved. Change the socket binding to take the l3mdev into account to allow an unbound socket to not conflict sockets bound to an l3mdev given the datapath isolation now guaranteed. Signed-off-by: Robert Shearman <rshearma@vyatta.att-mail.com> Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Add a 2nd listener hashtable (port+addr)Martin KaFai Lau2017-12-031-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current listener hashtable is hashed by port only. When a process is listening at many IP addresses with the same port (e.g. [IP1]:443, [IP2]:443... [IPN]:443), the inet[6]_lookup_listener() performance is degraded to a link list. It is prone to syn attack. UDP had a similar issue and a second hashtable was added to resolve it. This patch adds a second hashtable for the listener's sockets. The second hashtable is hashed by port and address. It cannot reuse the existing skc_portaddr_node which is shared with skc_bind_node. TCP listener needs to use skc_bind_node. Instead, this patch adds a hlist_node 'icsk_listen_portaddr_node' to the inet_connection_sock which the listener (like TCP) also belongs to. The new portaddr hashtable may need two lookup (First by IP:PORT. Second by INADDR_ANY:PORT if the IP:PORT is a not found). Hence, it implements a similar cut off as UDP such that it will only consult the new portaddr hashtable if the current port-only hashtable has >10 sk in the link-list. lhash2 and lhash2_mask are added to 'struct inet_hashinfo'. I take this chance to plug a 4 bytes hole. It is done by first moving the existing bind_bucket_cachep up and then add the new (int lhash2_mask, *lhash2) after the existing bhash_size. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Add a count to struct inet_listen_hashbucketMartin KaFai Lau2017-12-031-0/+1
| | | | | | | | | | | This patch adds a count to the 'struct inet_listen_hashbucket'. It counts how many sk is hashed to a bucket. It will be used to decide if the (to-be-added) portaddr listener's hashtable should be used during inet[6]_lookup_listener(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ipv4: add second dif to inet socket lookupsDavid Ahern2017-08-071-14/+17
| | | | | | | | | | | | | | Add a second device index, sdif, to inet socket lookups. sdif is the index for ingress devices enslaved to an l3mdev. It allows the lookups to consider the enslaved device as well as the L3 domain when searching for a socket. TCP moves the data in the cb. Prior to tcp_v4_rcv (e.g., early demux) the ingress index is obtained from IPCB using inet_sdif and after the cb move in tcp_v4_rcv the tcp_v4_sdif helper is used. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: make sk_ehashfn() staticEric Dumazet2017-07-031-1/+0
| | | | | | | sk_ehashfn() is only used from a single file. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: convert sock.sk_refcnt from atomic_t to refcount_tReshetova, Elena2017-07-011-2/+2
| | | | | | | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. This patch uses refcount_inc_not_zero() instead of atomic_inc_not_zero_hint() due to absense of a _hint() version of refcount API. If the hint() version must be used, we might need to revisit API. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: reset tb->fastreuseport when adding a reuseport skJosef Bacik2017-01-181-0/+9
| | | | | | | | | | | | | | | | | If we have non reuseport sockets on a tb we will set tb->fastreuseport to 0 and never set it again. Which means that in the future if we end up adding a bunch of reuseport sk's to that tb we'll have to do the expensive scan every time. Instead add the ipv4/ipv6 saddr fields to the bind bucket, as well as the family so we know what comparison to make, and the ipv6 only setting so we can make sure to compare with new sockets appropriately. Once one sk has made it onto the list we know that there are no potential bind conflicts on the owners list that match that sk's rcv_addr. So copy the sk's information into our bind bucket and set tb->fastruseport to FASTREUSESOCK_STRICT so we know we have to do an extra check for subsequent reuseport sockets and skip the expensive bind conflict check. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: kill smallest_size and smallest_portJosef Bacik2017-01-181-1/+0
| | | | | | | | | | | | | | | | | | | | In inet_csk_get_port we seem to be using smallest_port to figure out where the best place to look for a SO_REUSEPORT sk that matches with an existing set of SO_REUSEPORT's. However if we get to the logic if (smallest_size != -1) { port = smallest_port; goto have_port; } we will do a useless search, because we would have already done the inet_csk_bind_conflict for that port and it would have returned 1, otherwise we would have gone to found_tb and succeeded. Since this logic makes us do yet another trip through inet_csk_bind_conflict for a port we know won't work just delete this code and save us the time. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: collapse ipv4/v6 rcv_saddr_equal functions into oneJosef Bacik2017-01-181-4/+1
| | | | | | | | | | We pass these per-protocol equal functions around in various places, but we can just have one function that checks the sk->sk_family and then do the right comparison function. I've also changed the ipv4 version to not cast to inet_sock since it is unneeded. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp/dccp: do not touch listener sk_refcnt under synfloodEric Dumazet2016-04-041-16/+24
| | | | | | | | | | | | | | | | | | | | | When a SYNFLOOD targets a non SO_REUSEPORT listener, multiple cpus contend on sk->sk_refcnt and sk->sk_wmem_alloc changes. By letting listeners use SOCK_RCU_FREE infrastructure, we can relax TCP_LISTEN lookup rules and avoid touching sk_refcnt Note that we still use SLAB_DESTROY_BY_RCU rules for other sockets, only listeners are impacted by this change. Peak performance under SYNFLOOD is increased by ~33% : On my test machine, I could process 3.2 Mpps instead of 2.4 Mpps Most consuming functions are now skb_set_owner_w() and sock_wfree() contending on sk->sk_wmem_alloc when cooking SYNACK and freeing them. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp/dccp: remove BH disable/enable in lookupEric Dumazet2016-04-041-6/+1
| | | | | | | Since linux 2.6.29, lookups only use rcu locking. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* soreuseport: fast reuseport TCP socket selectionCraig Gallek2016-02-111-1/+4
| | | | | | | | | | | | | | | | This change extends the fast SO_REUSEPORT socket lookup implemented for UDP to TCP. Listener sockets with SO_REUSEPORT and the same receive address are additionally added to an array for faster random access. This means that only a single socket from the group must be found in the listener list before any socket in the group can be used to receive a packet. Previously, every socket in the group needed to be considered before handing off the incoming packet. This feature also exposes the ability to use a BPF program when selecting a socket from a reuseport group. Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: refactor inet[6]_lookup functions to take skbCraig Gallek2016-02-111-6/+12
| | | | | | | | | | | This is a preliminary step to allow fast socket lookup of SO_REUSEPORT groups. Doing so with a BPF filter will require access to the skb in question. This change plumbs the skb (and offset to payload data) through the call stack to the listening socket lookup implementations where it will be used in a following patch. Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sock: struct proto hash function may errorCraig Gallek2016-02-111-1/+1
| | | | | | | | | | | In order to support fast reuseport lookups in TCP, the hash function defined in struct proto must be capable of returning an error code. This patch changes the function signature of all related hash functions to return an integer and handles or propagates this return value at all call sites. Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp/dccp: fix hashdance race for passive sessionsEric Dumazet2015-10-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | Multiple cpus can process duplicates of incoming ACK messages matching a SYN_RECV request socket. This is a rare event under normal operations, but definitely can happen. Only one must win the race, otherwise corruption would occur. To fix this without adding new atomic ops, we use logic in inet_ehash_nolisten() to detect the request was present in the same ehash bucket where we try to insert the new child. If request socket was not found, we have to undo the child creation. This actually removes a spin_lock()/spin_unlock() pair in reqsk_queue_unlink() for the fast path. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-02 01:23:49 +0000