• Lorenzo Colitti's avatar
    net: diag: document swapped src/dst in udp_dump_one. · 747569b0
    Lorenzo Colitti authored
    Since its inception, udp_dump_one has had a bug where userspace
    needs to swap src and dst addresses and ports in order to find
    the socket it wants. This is because it passes the socket source
    address to __udp[46]_lib_lookup's saddr argument, but those
    functions are intended to find local sockets matching received
    packets, so saddr is the remote address, not the local address.
    This can no longer be fixed for backwards compatibility reasons,
    so add a brief comment explaining that this is the case. This
    will avoid confusion and help ensure SOCK_DIAG implementations
    of new protocols don't have the same problem.
    Fixes: a925aa00 ("udp_diag: Implement the get_exact dumping functionality")
    Signed-off-by: default avatarLorenzo Colitti <lorenzo@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
udp_diag.c 7.55 KB