kernel/git/stable/linux.git/include/net/tcp.h, branch linux-5.7.y

tcp: correct read of TFO keys on big endian systems

2020-08-19T06:24:10+00:00

[ Upstream commit f19008e676366c44e9241af57f331b6c6edf9552 ] When TFO keys are read back on big endian systems either via the global sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values don't match what was written. For example, on s390x: # echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key # cat /proc/sys/net/ipv4/tcp_fastopen_key 02000000-01000000-04000000-03000000 Instead of: # cat /proc/sys/net/ipv4/tcp_fastopen_key 00000001-00000002-00000003-00000004 Fix this by converting to the correct endianness on read. This was reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net selftest on s390x, which depends on the read value matching what was written. I've confirmed that the test now passes on big and little endian systems. Signed-off-by: Jason Baron Fixes: 438ac88009bc ("net: fastopen: robustness and endianness fixes for SipHash") Cc: Ard Biesheuvel Cc: Eric Dumazet Reported-and-tested-by: Colin Ian King Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix SO_RCVLOWAT hangs with fat skbs

2020-05-12T19:49:47+00:00

We autotune rcvbuf whenever SO_RCVLOWAT is set to account for 100% overhead in tcp_set_rcvlowat() This works well when skb->len/skb->truesize ratio is bigger than 0.5 But if we receive packets with small MSS, we can end up in a situation where not enough bytes are available in the receive queue to satisfy RCVLOWAT setting. As our sk_rcvbuf limit is hit, we send zero windows in ACK packets, preventing remote peer from sending more data. Even autotuning does not help, because it only triggers at the time user process drains the queue. If no EPOLLIN is generated, this can not happen. Note poll() has a similar issue, after commit c7004482e8dc ("tcp: Respect SO_RCVLOWAT in tcp_poll().") Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users") Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

net: remove spurious declaration of tcp_default_init_rwnd()

2020-05-07T14:58:55+00:00

it doesn't actually exist... Test: builds and 'git grep tcp_default_init_rwnd' comes up empty Signed-off-by: Maciej Żenczykowski Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: cache line align MAX_TCP_HEADER

2020-04-18T22:47:28+00:00

TCP stack is dumb in how it cooks its output packets. Depending on MAX_HEADER value, we might chose a bad ending point for the headers. If we align the end of TCP headers to cache line boundary, we make sure to always use the smallest number of cache lines, which always help. Signed-off-by: Eric Dumazet Cc: Soheil Hassas Yeganeh Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

bpf, tcp: Make tcp_bpf_recvmsg static

2020-03-20T14:56:55+00:00

After commit f747632b608f ("bpf: sockmap: Move generic sockmap hooks from BPF TCP"), tcp_bpf_recvmsg() is not used out of tcp_bpf.c, so make it static and remove it from tcp.h. Also move it to BPF_STREAM_PARSER #ifdef to fix unused function warnings. Fixes: f747632b608f ("bpf: sockmap: Move generic sockmap hooks from BPF TCP") Signed-off-by: YueHaibing Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200320023426.60684-3-yuehaibing@huawei.com

bpf: sockmap: Move generic sockmap hooks from BPF TCP

2020-03-09T21:34:58+00:00

The init, close and unhash handlers from TCP sockmap are generic, and can be reused by UDP sockmap. Move the helpers into the sockmap code base and expose them. This requires tcp_bpf_get_proto and tcp_bpf_clone to be conditional on BPF_STREAM_PARSER. The moved functions are unmodified, except that sk_psock_unlink is renamed to sock_map_unlink to better match its behaviour. Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200309111243.6982-6-lmb@cloudflare.com

bpf: tcp: Guard declarations with CONFIG_NET_SOCK_MSG

2020-03-09T21:34:58+00:00

tcp_bpf.c is only included in the build if CONFIG_NET_SOCK_MSG is selected. The declaration should therefore be guarded as such. Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200309111243.6982-5-lmb@cloudflare.com

bpf: tcp: Move assertions into tcp_bpf_get_proto

2020-03-09T21:34:58+00:00

We need to ensure that sk->sk_prot uses certain callbacks, so that code that directly calls e.g. tcp_sendmsg in certain corner cases works. To avoid spurious asserts, we must to do this only if sk_psock_update_proto has not yet been called. The same invariants apply for tcp_bpf_check_v6_needs_rebuild, so move the call as well. Doing so allows us to merge tcp_bpf_init and tcp_bpf_reinit. Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200309111243.6982-4-lmb@cloudflare.com

tcp_bpf: Don't let child socket inherit parent protocol ops on copy

2020-02-21T21:29:45+00:00

Prepare for cloning listening sockets that have their protocol callbacks overridden by sk_msg. Child sockets must not inherit parent callbacks that access state stored in sk_user_data owned by the parent. Restore the child socket protocol callbacks before it gets hashed and any of the callbacks can get invoked. Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200218171023.844439-4-jakub@cloudflare.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2020-01-23T07:10:16+00:00

Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-01-22 The following pull-request contains BPF updates for your *net-next* tree. We've added 92 non-merge commits during the last 16 day(s) which contain a total of 320 files changed, 7532 insertions(+), 1448 deletions(-). The main changes are: 1) function by function verification and program extensions from Alexei. 2) massive cleanup of selftests/bpf from Toke and Andrii. 3) batched bpf map operations from Brian and Yonghong. 4) tcp congestion control in bpf from Martin. 5) bulking for non-map xdp_redirect form Toke. 6) bpf_send_signal_thread helper from Yonghong. ==================== Signed-off-by: David S. Miller