cvs commit: src/sys/kern sys_socket.c

[Robert Watson]

rwatson     2005-04-01 15:02:12 UTC

  FreeBSD src repository

  Modified files:        (Branch: RELENG_5)
    sys/kern             sys_socket.c 
  Log:
  Merge sys_socket.c:1.68 from HEAD to RELENG_5:
  
    The SO_NOSIGPIPE socket option allows a user process to mark a socket
    so that the socket does not generate SIGPIPE, only EPIPE, when a write
    is attempted after socket shutdown.  When the option was introduced in
    2002, this required the logic for determining whether SIGPIPE was
    generated to be pushed down from dofilewrite() to the socket layer so
    that the socket options could be considered.  However, the change in
    2002 omitted modification to soo_write() required to add that logic,
    resulting in SIGPIPE not being generated even without SO_NOSIGPIPE when
    the socket was written to using write() or related generic system calls.
  
    This change adds the EPIPE logic to soo_write(), generating a SIGPIPE
    signal to the process associated with the passed uio in the event that
    the SO_NOSIGPIPE option is not set.
  
    Notes:
  
    - The are upsides and downsides to placing this logic in the socket
      layer as opposed to the file descriptor layer.  This is really fd
      layer logic, but because we need so_options, we have a choice of
      layering violations and pick this one.
  
    - SIGPIPE possibly should be delivered to the thread performing the
      write, not the process performing the write.
  
    - uio->uio_td and the td argument to soo_write() might potentially
      differ; we use the thread in the uio argument.
  
    - The "sigpipe" regression test in src/tools/regression/sockets/sigpipe
      tests for the bug.
  
    Submitted by:           Mikko Tyolajarvi <mbsd at pacbell dot net>
    Talked with:            glebius, alfred
    PR:                     78478
  
  Approved by:    re (scottl)
  
  Revision  Changes    Path
  1.63.2.3  +8 -0      src/sys/kern/sys_socket.c