cvs commit: src/sys/netinet tcp_input.c tcp_subr.c tcp_timer.c

[Robert Watson]

rwatson     2004-11-23 17:21:30 UTC

  FreeBSD src repository

  Modified files:
    sys/netinet          tcp_input.c tcp_subr.c tcp_timer.c 
  Log:
  tcp_timewait() performs multiple non-atomic reads on the tcptw
  structure, so assert the inpcb lock associated with the tcptw.
  Also assert the tcbinfo lock, as tcp_timewait() may call
  tcp_twclose() or tcp_2msl_rest(), which require it.  Since
  tcp_timewait() is already called with that lock from tcp_input(),
  this doesn't change current locking, merely documents reasons for
  it.
  
  In tcp_twstart(), assert the tcbinfo lock, as tcp_timer_2msl_rest()
  is called, which requires that lock.
  
  In tcp_twclose(), assert the tcbinfo lock, as tcp_timer_2msl_stop()
  is called, which requires that lock.
  
  Document the locking strategy for the time wait queues in tcp_timer.c,
  which consists of protecting the time wait queues in the same manner
  as the tcbinfo structure (using the tcbinfo lock).
  
  In tcp_timer_2msl_reset(), assert the tcbinfo lock, as the time wait
  queues are modified.
  
  In tcp_timer_2msl_stop(), assert the tcbinfo lock, as the time wait
  queues may be modified.
  
  In tcp_timer_2msl_tw(), assert the tcbinfo lock, as the time wait
  queues may be modified.
  
  MFC after:      2 weeks
  
  Revision  Changes    Path
  1.257     +4 -0      src/sys/netinet/tcp_input.c
  1.211     +2 -0      src/sys/netinet/tcp_subr.c
  1.69      +9 -0      src/sys/netinet/tcp_timer.c