bpf, sockmap: Do not inc copied_seq when PEEK flag set
When data is peek'd off the receive queue we shouldn't considered it copied from tcp_sock side. When we increment copied_seq this will confuse tcp_data_ready() because copied_seq can be arbitrarily increased. From application side it results in poll() operations not waking up when expected. Notice tcp stack without BPF recvmsg programs also does not increment copied_seq. We broke this when we moved copied_seq into recvmsg to only update when actual copy was happening. But, it wasn't working correctly either before because the tcp_data_ready() tried to use the copied_seq value to see if data was read by user yet. See fixes tags. Fixes: e5c6de5f ("bpf, sockmap: Incorrectly handling copied_seq") Fixes: 04919bed ("tcp: Introduce tcp_read_skb()") Signed-off-by:John Fastabend <john.fastabend@gmail.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Reviewed-by:
Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20230926035300.135096-3-john.fastabend@gmail.com
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