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2023-09-01net: annotate data-races around sk->sk_tsflagsEric Dumazet
sk->sk_tsflags can be read locklessly, add corresponding annotations. Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16inet: introduce inet->inet_flagsEric Dumazet
Various inet fields are currently racy. do_ip_setsockopt() and do_ip_getsockopt() are mostly holding the socket lock, but some (fast) paths do not. Use a new inet->inet_flags to hold atomic bits in the series. Remove inet->cmsg_flags, and use instead 9 bits from inet_flags. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-03Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Martin KaFai Lau says: ==================== pull-request: bpf-next 2023-08-03 We've added 54 non-merge commits during the last 10 day(s) which contain a total of 84 files changed, 4026 insertions(+), 562 deletions(-). The main changes are: 1) Add SO_REUSEPORT support for TC bpf_sk_assign from Lorenz Bauer, Daniel Borkmann 2) Support new insns from cpu v4 from Yonghong Song 3) Non-atomically allocate freelist during prefill from YiFei Zhu 4) Support defragmenting IPv(4|6) packets in BPF from Daniel Xu 5) Add tracepoint to xdp attaching failure from Leon Hwang 6) struct netdev_rx_queue and xdp.h reshuffling to reduce rebuild time from Jakub Kicinski * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits) net: invert the netdevice.h vs xdp.h dependency net: move struct netdev_rx_queue out of netdevice.h eth: add missing xdp.h includes in drivers selftests/bpf: Add testcase for xdp attaching failure tracepoint bpf, xdp: Add tracepoint to xdp attaching failure selftests/bpf: fix static assert compilation issue for test_cls_*.c bpf: fix bpf_probe_read_kernel prototype mismatch riscv, bpf: Adapt bpf trampoline to optimized riscv ftrace framework libbpf: fix typos in Makefile tracing: bpf: use struct trace_entry in struct syscall_tp_t bpf, devmap: Remove unused dtab field from bpf_dtab_netdev bpf, cpumap: Remove unused cmap field from bpf_cpu_map_entry netfilter: bpf: Only define get_proto_defrag_hook() if necessary bpf: Fix an array-index-out-of-bounds issue in disasm.c net: remove duplicate INDIRECT_CALLABLE_DECLARE of udp[6]_ehashfn docs/bpf: Fix malformed documentation bpf: selftests: Add defrag selftests bpf: selftests: Support custom type and proto for client sockets bpf: selftests: Support not connecting client socket netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link ... ==================== Link: https://lore.kernel.org/r/20230803174845.825419-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/dsa/port.c 9945c1fb03a3 ("net: dsa: fix older DSA drivers using phylink") a88dd7538461 ("net: dsa: remove legacy_pre_march2020 detection") https://lore.kernel.org/all/20230731102254.2c9868ca@canb.auug.org.au/ net/xdp/xsk.c 3c5b4d69c358 ("net: annotate data-races around sk->sk_mark") b7f72a30e9ac ("xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path") https://lore.kernel.org/all/20230731102631.39988412@canb.auug.org.au/ drivers/net/ethernet/broadcom/bnxt/bnxt.c 37b61cda9c16 ("bnxt: don't handle XDP in netpoll") 2b56b3d99241 ("eth: bnxt: handle invalid Tx completions more gracefully") https://lore.kernel.org/all/20230801101708.1dc7faac@canb.auug.org.au/ Adjacent changes: drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c 62da08331f1a ("net/mlx5e: Set proper IPsec source port in L4 selector") fbd517549c32 ("net/mlx5e: Add function to get IPsec offload namespace") drivers/net/ethernet/sfc/selftest.c 55c1528f9b97 ("sfc: fix field-spanning memcpy in selftest") ae9d445cd41f ("sfc: Miscellaneous comment removals") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-29net: annotate data-races around sk->sk_markEric Dumazet
sk->sk_mark is often read while another thread could change the value. Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-29net: gro: fix misuse of CB in udp socket lookupRichard Gobert
This patch fixes a misuse of IP{6}CB(skb) in GRO, while calling to `udp6_lib_lookup2` when handling udp tunnels. `udp6_lib_lookup2` fetch the device from CB. The fix changes it to fetch the device from `skb->dev`. l3mdev case requires special attention since it has a master and a slave device. Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket") Reported-by: Gal Pressman <gal@nvidia.com> Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-25bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assignLorenz Bauer
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>
2023-07-25net: remove duplicate sk_lookup helpersLorenz Bauer
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>
2023-07-25net: remove duplicate reuseport_lookup functionsLorenz Bauer
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>
2023-07-25udp: re-score reuseport groups when connected sockets are presentLorenz Bauer
Contrary to TCP, UDP reuseport groups can contain TCP_ESTABLISHED sockets. To support these properly we remember whether a group has a connected socket and skip the fast reuseport early-return. In effect we continue scoring all reuseport sockets and then choose the one with the highest score. The current code fails to re-calculate the score for the result of lookup_reuseport. According to Kuniyuki Iwashima: 1) SO_INCOMING_CPU is set -> selected sk might have +1 score 2) BPF prog returns ESTABLISHED and/or SO_INCOMING_CPU sk -> selected sk will have more than 8 Using the old score could trigger more lookups depending on the order that sockets are created. sk -> sk (SO_INCOMING_CPU) -> sk (ESTABLISHED) | | `-> select the next SO_INCOMING_CPU sk | `-> select itself (We should save this lookup) Fixes: efc6b6f6c311 ("udp: Improve load balancing for SO_REUSEPORT.") Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-1-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-07-24ipv6: remove hard coded limitation on ipv6_pinfoEric Dumazet
IPv6 inet sockets are supposed to have a "struct ipv6_pinfo" field at the end of their definition, so that inet6_sk_generic() can derive from socket size the offset of the "struct ipv6_pinfo". This is very fragile, and prevents adding bigger alignment in sockets, because inet6_sk_generic() does not work if the compiler adds padding after the ipv6_pinfo component. We are currently working on a patch series to reorganize TCP structures for better data locality and found issues similar to the one fixed in commit f5d547676ca0 ("tcp: fix tcp_inet6_sk() for 32bit kernels") Alternative would be to force an alignment on "struct ipv6_pinfo", greater or equal to __alignof__(any ipv6 sock) to ensure there is no padding. This does not look great. v2: fix typo in mptcp_proto_v6_init() (Paolo) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Chao Wu <wwchao@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-08udp6: fix udp6_ehashfn() typoEric Dumazet
Amit Klein reported that udp6_ehash_secret was initialized but never used. Fixes: 1bbdceef1e53 ("inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once") Reported-by: Amit Klein <aksecurity@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: David Ahern <dsahern@kernel.org> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-07udp6: add a missing call into udp_fail_queue_rcv_skb tracepointIvan Babrou
The tracepoint has existed for 12 years, but it only covered udp over the legacy IPv4 protocol. Having it enabled for udp6 removes the unnecessary difference in error visibility. Signed-off-by: Ivan Babrou <ivan@cloudflare.com> Fixes: 296f7ea75b45 ("udp: add tracepoints for queueing skb to rcvbuf") Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-08ipv4, ipv6: Use splice_eof() to flushDavid Howells
Allow splice to undo the effects of MSG_MORE after prematurely ending a splice/sendfile due to getting an EOF condition (->splice_read() returned 0) after splice had called sendmsg() with MSG_MORE set when the user didn't set MSG_MORE. For UDP, a pending packet will not be emitted if the socket is closed before it is flushed; with this change, it be flushed by ->splice_eof(). For TCP, it's not clear that MSG_MORE is actually effective. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/ Signed-off-by: David Howells <dhowells@redhat.com> cc: Kuniyuki Iwashima <kuniyu@amazon.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: tools/testing/selftests/net/config 62199e3f1658 ("selftests: net: Add VXLAN MDB test") 3a0385be133e ("selftests: add the missing CONFIG_IP_SCTP in net config") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-13udp6: fix potential access to stale informationEric Dumazet
lena wang reported an issue caused by udpv6_sendmsg() mangling msg->msg_name and msg->msg_namelen, which are later read from ____sys_sendmsg() : /* * If this is sendmmsg() and sending to current destination address was * successful, remember it. */ if (used_address && err >= 0) { used_address->name_len = msg_sys->msg_namelen; if (msg_sys->msg_name) memcpy(&used_address->name, msg_sys->msg_name, used_address->name_len); } udpv6_sendmsg() wants to pretend the remote address family is AF_INET in order to call udp_sendmsg(). A fix would be to modify the address in-place, instead of using a local variable, but this could have other side effects. Instead, restore initial values before we return from udpv6_sendmsg(). Fixes: c71d8ebe7a44 ("net: Fix security_socket_sendmsg() bypass problem.") Reported-by: lena wang <lena.wang@mediatek.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://lore.kernel.org/r/20230412130308.1202254-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-22netfilter: keep conntrack reference until IPsecv6 policy checks are doneMadhu Koriginja
Keep the conntrack reference until policy checks have been performed for IPsec V6 NAT support, just like ipv4. The reference needs to be dropped before a packet is queued to avoid having the conntrack module unloadable. Fixes: 58a317f1061c ("netfilter: ipv6: add IPv6 NAT support") Signed-off-by: Madhu Koriginja <madhu.koriginja@nxp.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2023-03-17udp6: constify __udp_v6_is_mcast_sock() socket argumentEric Dumazet
This clarifies __udp_v6_is_mcast_sock() intent. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-17inet: preserve const qualifier in inet_sk()Eric Dumazet
We can change inet_sk() to propagate const qualifier of its argument. This should avoid some potential errors caused by accidental (const -> not_const) promotion. Other helpers like tcp_sk(), udp_sk(), raw_sk() will be handled in separate patch series. v2: use container_of_const() as advised by Jakub and Linus Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/20230315142841.3a2ac99a@kernel.org/ Link: https://lore.kernel.org/netdev/CAHk-=wiOf12nrYEF2vJMcucKjWPN-Ns_SW9fA7LwST_2Dzp7rw@mail.gmail.com/ Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-16udp: Access &udp_table via net.Kuniyuki Iwashima
We will soon introduce an optional per-netns hash table for UDP. This means we cannot use udp_table directly in most places. Instead, access it via net->ipv4.udp_table. The access will be valid only while initialising udp_table itself and creating/destroying each netns. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-16udp: Set NULL to udp_seq_afinfo.udp_table.Kuniyuki Iwashima
We will soon introduce an optional per-netns hash table for UDP. This means we cannot use the global udp_seq_afinfo.udp_table to fetch a UDP hash table. Instead, set NULL to udp_seq_afinfo.udp_table for UDP and get a proper table from net->ipv4.udp_table. Note that we still need udp_seq_afinfo.udp_table for UDP LITE. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-16udp: Set NULL to sk->sk_prot->h.udp_table.Kuniyuki Iwashima
We will soon introduce an optional per-netns hash table for UDP. This means we cannot use the global sk->sk_prot->h.udp_table to fetch a UDP hash table. Instead, set NULL to sk->sk_prot->h.udp_table for UDP and get a proper table from net->ipv4.udp_table. Note that we still need sk->sk_prot->h.udp_table for UDP LITE. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-16udp: Clean up some functions.Kuniyuki Iwashima
This patch adds no functional change and cleans up some functions that the following patches touch around so that we make them tidy and easy to review/revert. The change is mainly to keep reverse christmas tree order. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-09Merge tag 'rxrpc-next-20221108' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs rxrpc changes David Howells says: ==================== rxrpc: Increasing SACK size and moving away from softirq, part 1 AF_RXRPC has some issues that need addressing: (1) The SACK table has a maximum capacity of 255, but for modern networks that isn't sufficient. This is hard to increase in the upstream code because of the way the application thread is coupled to the softirq and retransmission side through a ring buffer. Adjustments to the rx protocol allows a capacity of up to 8192, and having a ring sufficiently large to accommodate that would use an excessive amount of memory as this is per-call. (2) Processing ACKs in softirq mode causes the ACKs get conflated, with only the most recent being considered. Whilst this has the upside that the retransmission algorithm only needs to deal with the most recent ACK, it causes DATA transmission for a call to be very bursty because DATA packets cannot be transmitted in softirq mode. Rather transmission must be delegated to either the application thread or a workqueue, so there tend to be sudden bursts of traffic for any particular call due to scheduling delays. (3) All crypto in a single call is done in series; however, each DATA packet is individually encrypted so encryption and decryption of large calls could be parallelised if spare CPU resources are available. This is the first of a number of sets of patches that try and address them. The overall aims of these changes include: (1) To get rid of the TxRx ring and instead pass the packets round in queues (eg. sk_buff_head). On the Tx side, each ACK packet comes with a SACK table that can be parsed as-is, so there's no particular need to maintain our own; we just have to refer to the ACK. On the Rx side, we do need to maintain a SACK table with one bit per entry - but only if packets go missing - and we don't want to have to perform a complex transformation to get the information into an ACK packet. (2) To try and move almost all processing of received packets out of the softirq handler and into a high-priority kernel I/O thread. Only the transferral of packets would be left there. I would still use the encap_rcv hook to receive packets as there's a noticeable performance drop from letting the UDP socket put the packets into its own queue and then getting them out of there. (3) To make the I/O thread also do all the transmission. The app thread would be responsible for packaging the data into packets and then buffering them for the I/O thread to transmit. This would make it easier for the app thread to run ahead of the I/O thread, and would mean the I/O thread is less likely to have to wait around for a new packet to come available for transmission. (4) To logically partition the socket/UAPI/KAPI side of things from the I/O side of things. The local endpoint, connection, peer and call objects would belong to the I/O side. The socket side would not then touch the private internals of calls and suchlike and would not change their states. It would only look at the send queue, receive queue and a way to pass a message to cause an abort. (5) To remove as much locking, synchronisation, barriering and atomic ops as possible from the I/O side. Exclusion would be achieved by limiting modification of state to the I/O thread only. Locks would still need to be used in communication with the UDP socket and the AF_RXRPC socket API. (6) To provide crypto offload kernel threads that, when there's slack in the system, can see packets that need crypting and provide parallelisation in dealing with them. (7) To remove the use of system timers. Since each timer would then send a poke to the I/O thread, which would then deal with it when it had the opportunity, there seems no point in using system timers if, instead, a list of timeouts can be sensibly consulted. An I/O thread only then needs to schedule with a timeout when it is idle. (8) To use zero-copy sendmsg to send packets. This would make use of the I/O thread being the sole transmitter on the socket to manage the dead-reckoning sequencing of the completion notifications. There is a problem with zero-copy, though: the UDP socket doesn't handle running out of option memory very gracefully. With regard to this first patchset, the changes made include: (1) Some fixes, including a fallback for proc_create_net_single_write(), setting ack.bufferSize to 0 in ACK packets and a fix for rxrpc congestion management, which shouldn't be saving the cwnd value between calls. (2) Improvements in rxrpc tracepoints, including splitting the timer tracepoint into a set-timer and a timer-expired trace. (3) Addition of a new proc file to display some stats. (4) Some code cleanups, including removing some unused bits and unnecessary header inclusions. (5) A change to the recently added UDP encap_err_rcv hook so that it has the same signature as {ip,ipv6}_icmp_error(), and then just have rxrpc point its UDP socket's hook directly at those. (6) Definition of a new struct, rxrpc_txbuf, that is used to hold transmissible packets of DATA and ACK type in a single 2KiB block rather than using an sk_buff. This allows the buffer to be on a number of queues simultaneously more easily, and also guarantees that the entire block is in a single unit for zerocopy purposes and that the data payload is aligned for in-place crypto purposes. (7) ACK txbufs are allocated at proposal and queued for later transmission rather than being stored in a single place in the rxrpc_call struct, which means only a single ACK can be pending transmission at a time. The queue is then drained at various points. This allows the ACK generation code to be simplified. (8) The Rx ring buffer is removed. When a jumbo packet is received (which comprises a number of ordinary DATA packets glued together), it used to be pointed to by the ring multiple times, with an annotation in a side ring indicating which subpacket was in that slot - but this is no longer possible. Instead, the packet is cloned once for each subpacket, barring the last, and the range of data is set in the skb private area. This makes it easier for the subpackets in a jumbo packet to be decrypted in parallel. (9) The Tx ring buffer is removed. The side annotation ring that held the SACK information is also removed. Instead, in the event of packet loss, the SACK data attached an ACK packet is parsed. (10) Allocate an skcipher request when needed in the rxkad security class rather than caching one in the rxrpc_call struct. This deals with a race between externally-driven call disconnection getting rid of the skcipher request and sendmsg/recvmsg trying to use it because they haven't seen the completion yet. This is also needed to support parallelisation as the skcipher request cannot be used by two or more threads simultaneously. (11) Call udp_sendmsg() and udpv6_sendmsg() directly rather than going through kernel_sendmsg() so that we can provide our own iterator (zerocopy explicitly doesn't work with a KVEC iterator). This also lets us avoid the overhead of the security hook. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-08rxrpc: Call udp_sendmsg() directlyDavid Howells
Call udp_sendmsg() and udpv6_sendmsg() directly rather than calling kernel_sendmsg() as the latter assumes we want a kvec-class iterator. However, zerocopy explicitly doesn't work with such an iterator. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08net: Change the udp encap_err_rcv to allow use of {ip,ipv6}_icmp_error()David Howells
Change the udp encap_err_rcv signature to match ip_icmp_error() and ipv6_icmp_error() so that those can be used from the called function and export them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2022-11-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-28udp: advertise ipv6 udp support for msghdr::ubuf_infoPavel Begunkov
Mark udp ipv6 as supporting msghdr::ubuf_info. In the original commit SOCK_SUPPORT_ZC was supposed to be set by a udp_init_sock() call from udp6_init_sock(), but d38afeec26ed4 ("tcp/udp: Call inet6_destroy_sock() in IPv6 ...") removed it and so ipv6 udp misses the flag. Cc: <stable@vger.kernel.org> # 6.0 Fixes: e993ffe3da4bc ("net: flag sockets supporting msghdr originated zerocopy") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-24udp: track the forward memory release threshold in an hot cachelinePaolo Abeni
When the receiver process and the BH runs on different cores, udp_rmem_release() experience a cache miss while accessing sk_rcvbuf, as the latter shares the same cacheline with sk_forward_alloc, written by the BH. With this patch, UDP tracks the rcvbuf value and its update via custom SOL_SOCKET socket options, and copies the forward memory threshold value used by udp_rmem_release() in a different cacheline, already accessed by the above function and uncontended. Since the UDP socket init operation grown a bit, factor out the common code between v4 and v6 in a shared helper. Overall the above give a 10% peek throughput increase under UDP flood. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-24inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().Kuniyuki Iwashima
After commit d38afeec26ed ("tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in sk->sk_destruct() by setting inet6_sock_destruct() to it to make sure we do not leak inet6-specific resources. Now we can remove unnecessary inet6_destroy_sock() calls in sk->sk_prot->destroy(). DCCP and SCTP have their own sk->sk_destruct() function, so we change them separately in the following patches. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-18udp: Update reuse->has_conns under reuseport_lock.Kuniyuki Iwashima
When we call connect() for a UDP socket in a reuseport group, we have to update sk->sk_reuseport_cb->has_conns to 1. Otherwise, the kernel could select a unconnected socket wrongly for packets sent to the connected socket. However, the current way to set has_conns is illegal and possible to trigger that problem. reuseport_has_conns() changes has_conns under rcu_read_lock(), which upgrades the RCU reader to the updater. Then, it must do the update under the updater's lock, reuseport_lock, but it doesn't for now. For this reason, there is a race below where we fail to set has_conns resulting in the wrong socket selection. To avoid the race, let's split the reader and updater with proper locking. cpu1 cpu2 +----+ +----+ __ip[46]_datagram_connect() reuseport_grow() . . |- reuseport_has_conns(sk, true) |- more_reuse = __reuseport_alloc(more_socks_size) | . | | |- rcu_read_lock() | |- reuse = rcu_dereference(sk->sk_reuseport_cb) | | | | | /* reuse->has_conns == 0 here */ | | |- more_reuse->has_conns = reuse->has_conns | |- reuse->has_conns = 1 | /* more_reuse->has_conns SHOULD BE 1 HERE */ | | | | | |- rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb, | | | more_reuse) | `- rcu_read_unlock() `- kfree_rcu(reuse, rcu) | |- sk->sk_state = TCP_ESTABLISHED Note the likely(reuse) in reuseport_has_conns_set() is always true, but we put the test there for ease of review. [0] For the record, usually, sk_reuseport_cb is changed under lock_sock(). The only exception is reuseport_grow() & TCP reqsk migration case. 1) shutdown() TCP listener, which is moved into the latter part of reuse->socks[] to migrate reqsk. 2) New listen() overflows reuse->socks[] and call reuseport_grow(). 3) reuse->max_socks overflows u16 with the new listener. 4) reuseport_grow() pops the old shutdown()ed listener from the array and update its sk->sk_reuseport_cb as NULL without lock_sock(). shutdown()ed TCP sk->sk_reuseport_cb can be changed without lock_sock(), but, reuseport_has_conns_set() is called only for UDP under lock_sock(), so likely(reuse) never be false in reuseport_has_conns_set(). [0]: https://lore.kernel.org/netdev/CANn89iLja=eQHbsM_Ta2sQF0tOGU8vAGrh_izRuuHjuO1ouUag@mail.gmail.com/ Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20221014182625.89913-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-10-12tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().Kuniyuki Iwashima
Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were able to clean them up by calling inet6_destroy_sock() during the IPv6 -> IPv4 conversion by IPV6_ADDRFORM. However, commit 03485f2adcde ("udpv6: Add lockless sendmsg() support") added a lockless memory allocation path, which could cause a memory leak: setsockopt(IPV6_ADDRFORM) sendmsg() +-----------------------+ +-------+ - do_ipv6_setsockopt(sk, ...) - udpv6_sendmsg(sk, ...) - sockopt_lock_sock(sk) ^._ called via udpv6_prot - lock_sock(sk) before WRITE_ONCE() - WRITE_ONCE(sk->sk_prot, &tcp_prot) - inet6_destroy_sock() - if (!corkreq) - sockopt_release_sock(sk) - ip6_make_skb(sk, ...) - release_sock(sk) ^._ lockless fast path for the non-corking case - __ip6_append_data(sk, ...) - ipv6_local_rxpmtu(sk, ...) - xchg(&np->rxpmtu, skb) ^._ rxpmtu is never freed. - goto out_no_dst; - lock_sock(sk) For now, rxpmtu is only the case, but not to miss the future change and a similar bug fixed in commit e27326009a3d ("net: ping6: Fix memleak in ipv6_renew_options()."), let's set a new function to IPv6 sk->sk_destruct() and call inet6_cleanup_sock() there. Since the conversion does not change sk->sk_destruct(), we can guarantee that we can clean up IPv6 resources finally. We can now remove all inet6_destroy_sock() calls from IPv6 protocol specific ->destroy() functions, but such changes are invasive to backport. So they can be posted as a follow-up later for net-next. Fixes: 03485f2adcde ("udpv6: Add lockless sendmsg() support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-27Add skb drop reasons to IPv6 UDP receive pathDonald Hunter
Enumerate the skb drop reasons in the receive path for IPv6 UDP packets. Signed-off-by: Donald Hunter <donald.hunter@redhat.com> Link: https://lore.kernel.org/r/20220926120350.14928-1-donald.hunter@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-01rxrpc: Fix ICMP/ICMP6 error handlingDavid Howells
Because rxrpc pretends to be a tunnel on top of a UDP/UDP6 socket, allowing it to siphon off UDP packets early in the handling of received UDP packets thereby avoiding the packet going through the UDP receive queue, it doesn't get ICMP packets through the UDP ->sk_error_report() callback. In fact, it doesn't appear that there's any usable option for getting hold of ICMP packets. Fix this by adding a new UDP encap hook to distribute error messages for UDP tunnels. If the hook is set, then the tunnel driver will be able to see ICMP packets. The hook provides the offset into the packet of the UDP header of the original packet that caused the notification. An alternative would be to call the ->error_handler() hook - but that requires that the skbuff be cloned (as ip_icmp_error() or ipv6_cmp_error() do, though isn't really necessary or desirable in rxrpc's case is we want to parse them there and then, not queue them). Changes ======= ver #3) - Fixed an uninitialised variable. ver #2) - Fixed some missing CONFIG_AF_RXRPC_IPV6 conditionals. Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells <dhowells@redhat.com>
2022-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-15tcp/udp: Make early_demux back namespacified.Kuniyuki Iwashima
Commit e21145a9871a ("ipv4: namespacify ip_early_demux sysctl knob") made it possible to enable/disable early_demux on a per-netns basis. Then, we introduced two knobs, tcp_early_demux and udp_early_demux, to switch it for TCP/UDP in commit dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp"). However, the .proc_handler() was wrong and actually disabled us from changing the behaviour in each netns. We can execute early_demux if net.ipv4.ip_early_demux is on and each proto .early_demux() handler is not NULL. When we toggle (tcp|udp)_early_demux, the change itself is saved in each netns variable, but the .early_demux() handler is a global variable, so the handler is switched based on the init_net's sysctl variable. Thus, netns (tcp|udp)_early_demux knobs have nothing to do with the logic. Whether we CAN execute proto .early_demux() is always decided by init_net's sysctl knob, and whether we DO it or not is by each netns ip_early_demux knob. This patch namespacifies (tcp|udp)_early_demux again. For now, the users of the .early_demux() handler are TCP and UDP only, and they are called directly to avoid retpoline. So, we can remove the .early_demux() handler from inet6?_protos and need not dereference them in ip6?_rcv_finish_core(). If another proto needs .early_demux(), we can restore it at that time. Fixes: dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20220713175207.7727-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-10net: add per_cpu_fw_alloc field to struct protoEric Dumazet
Each protocol having a ->memory_allocated pointer gets a corresponding per-cpu reserve, that following patches will use. Instead of having reserved bytes per socket, we want to have per-cpu reserves. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-16ipv6: add READ_ONCE(sk->sk_bound_dev_if) in INET6_MATCH()Eric Dumazet
INET6_MATCH() runs without holding a lock on the socket. We probably need to annotate most reads. This patch makes INET6_MATCH() an inline function to ease our changes. v2: inline function only defined if IS_ENABLED(CONFIG_IPV6) Change the name to inet6_match(), this is no longer a macro. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-16net: annotate races around sk->sk_bound_dev_ifEric Dumazet
UDP sendmsg() is lockless, and reads sk->sk_bound_dev_if while this field can be changed by another thread. Adds minimal annotations to avoid KCSAN splats for UDP. Following patches will add more annotations to potential lockless readers. BUG: KCSAN: data-race in __ip6_datagram_connect / udpv6_sendmsg write to 0xffff888136d47a94 of 4 bytes by task 7681 on cpu 0: __ip6_datagram_connect+0x6e2/0x930 net/ipv6/datagram.c:221 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272 inet_dgram_connect+0x107/0x190 net/ipv4/af_inet.c:576 __sys_connect_file net/socket.c:1900 [inline] __sys_connect+0x197/0x1b0 net/socket.c:1917 __do_sys_connect net/socket.c:1927 [inline] __se_sys_connect net/socket.c:1924 [inline] __x64_sys_connect+0x3d/0x50 net/socket.c:1924 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888136d47a94 of 4 bytes by task 7670 on cpu 1: udpv6_sendmsg+0xc60/0x16e0 net/ipv6/udp.c:1436 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:652 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0xffffff9b Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7670 Comm: syz-executor.3 Tainted: G W 5.18.0-rc1-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 I chose to not add Fixes: tag because race has minor consequences and stable teams busy enough. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-28net: SO_RCVMARK socket option for SO_MARK with recvmsg()Erin MacNeil
Adding a new socket option, SO_RCVMARK, to indicate that SO_MARK should be included in the ancillary data returned by recvmsg(). Renamed the sock_recv_ts_and_drops() function to sock_recv_cmsgs(). Signed-off-by: Erin MacNeil <lnx.erin@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/20220427200259.2564-1-lnx.erin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-22ipv6: Remove __ipv6_only_sock().Kuniyuki Iwashima
Since commit 9fe516ba3fb2 ("inet: move ipv6only in sock_common"), ipv6_only_sock() and __ipv6_only_sock() are the same macro. Let's remove the one. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-12net: remove noblock parameter from recvmsg() entitiesOliver Hartkopp
The internal recvmsg() functions have two parameters 'flags' and 'noblock' that were merged inside skb_recv_datagram(). As a follow up patch to commit f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()") this patch removes the separate 'noblock' parameter for recvmsg(). Analogue to the referenced patch for skb_recv_datagram() the 'flags' and 'noblock' parameters are unnecessarily split up with e.g. err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); or in err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg, sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); instead of simply using only flags all the time and check for MSG_DONTWAIT where needed (to preserve for the formerly separated no(n)block condition). Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-02-14ipv6: Add reasons for skb drops to __udp6_lib_rcvDavid Ahern
Add reasons to __udp6_lib_rcv for skb drops. The only twist is that the NO_SOCKET takes precedence over the CSUM or other counters for that path (motivation behind this patch - csum counter was misleading). Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-27ipv6: optimise dst refcounting on cork initPavel Begunkov
udpv6_sendmsg() doesn't need dst after calling ip6_make_skb(), so instead of taking an additional reference inside ip6_setup_cork() and releasing the initial one afterwards, we can hand over a reference into ip6_make_skb() saving two atomics. The only other user of ip6_setup_cork() is ip6_append_data() and it requires an extra dst_hold(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27udp6: don't make extra copies of iflowPavel Begunkov
udpv6_sendmsg() first initialises an on-stack 88B struct flowi6 and then copies it into cork, which is expensive. Avoid the copy in corkless case by initialising on-stack cork->fl directly. The main part is a couple of lines under !corkreq check. The rest converts fl6 variable to be a pointer. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27udp6: pass flow in ip6_make_skb together with corkPavel Begunkov
Another preparation patch. inet_cork_full already contains a field for iflow, so we can avoid passing a separate struct iflow6 into __ip6_append_data() and ip6_make_skb(), and use the flow stored in inet_cork_full. Make sure callers set cork->fl, i.e. we init it in ip6_append_data() and before calling ip6_make_skb(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27ipv6: don't zero inet_cork_full::fl after usePavel Begunkov
It doesn't appear there is any reason for ip6_cork_release() to zero cork->fl, it'll be fully filled on next initialisation. This 88 bytes memset accounts to 0.3-0.5% of total CPU cycles. It's also needed in following patches and allows to remove an extar flow copy in udp_v6_push_pending_frames(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27udp6: shuffle up->pending AF_INET bitsPavel Begunkov
Corked AF_INET for ipv6 socket doesn't appear to be the hottest case, so move it out of the common path under up->pending check to remove overhead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-06Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf-next 2022-01-06 We've added 41 non-merge commits during the last 2 day(s) which contain a total of 36 files changed, 1214 insertions(+), 368 deletions(-). The main changes are: 1) Various fixes in the verifier, from Kris and Daniel. 2) Fixes in sockmap, from John. 3) bpf_getsockopt fix, from Kuniyuki. 4) INET_POST_BIND fix, from Menglong. 5) arm64 JIT fix for bpf pseudo funcs, from Hou. 6) BPF ISA doc improvements, from Christoph. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (41 commits) bpf: selftests: Add bind retry for post_bind{4, 6} bpf: selftests: Use C99 initializers in test_sock.c net: bpf: Handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() bpf/selftests: Test bpf_d_path on rdonly_mem. libbpf: Add documentation for bpf_map batch operations selftests/bpf: Don't rely on preserving volatile in PT_REGS macros in loop3 xdp: Add xdp_do_redirect_frame() for pre-computed xdp_frames xdp: Move conversion to xdp_frame out of map functions page_pool: Store the XDP mem id page_pool: Add callback to init pages when they are allocated xdp: Allow registering memory model without rxq reference samples/bpf: xdpsock: Add timestamp for Tx-only operation samples/bpf: xdpsock: Add time-out for cleaning Tx samples/bpf: xdpsock: Add sched policy and priority support samples/bpf: xdpsock: Add cyclic TX operation capability samples/bpf: xdpsock: Add clockid selection support samples/bpf: xdpsock: Add Dest and Src MAC setting for Tx-only operation samples/bpf: xdpsock: Add VLAN support for Tx-only operation libbpf 1.0: Deprecate bpf_object__find_map_by_offset() API libbpf 1.0: Deprecate bpf_map__is_offload_neutral() ... ==================== Link: https://lore.kernel.org/r/20220107013626.53943-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-06net: bpf: Handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND()Menglong Dong
The return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() in __inet_bind() is not handled properly. While the return value is non-zero, it will set inet_saddr and inet_rcv_saddr to 0 and exit: err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; goto out_release_sock; } Let's take UDP for example and see what will happen. For UDP socket, it will be added to 'udp_prot.h.udp_table->hash' and 'udp_prot.h.udp_table->hash2' after the sk->sk_prot->get_port() called success. If 'inet->inet_rcv_saddr' is specified here, then 'sk' will be in the 'hslot2' of 'hash2' that it don't belong to (because inet_saddr is changed to 0), and UDP packet received will not be passed to this sock. If 'inet->inet_rcv_saddr' is not specified here, the sock will work fine, as it can receive packet properly, which is wired, as the 'bind()' is already failed. To undo the get_port() operation, introduce the 'put_port' field for 'struct proto'. For TCP proto, it is inet_put_port(); For UDP proto, it is udp_lib_unhash(); For icmp proto, it is ping_unhash(). Therefore, after sys_bind() fail caused by BPF_CGROUP_RUN_PROG_INET4_POST_BIND(), it will be unbinded, which means that it can try to be binded to another port. Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220106132022.3470772-2-imagedong@tencent.com