• Chuck Lever's avatar
    SUNRPC: Properly initialize sock_xprt.srcaddr in all cases · 92476850
    Chuck Lever authored
    The source address field in the transport's sock_xprt is initialized
    ONLY IF the RPC application passed a pointer to a source address
    during the call to rpc_create().  However, xs_bind() subsequently uses
    the value of this field without regard to whether the source address
    was initialized during transport creation or not.
    So far we've been lucky: the uninitialized value of this field is
    zeroes.  xs_bind(), until recently, used only the sin[6]_addr field in
    this sockaddr, and all zeroes is a valid value for this: it means
    ANYADDR.  This is a happy coincidence.
    However, xs_bind() now wants to use the sa_family field as well, and
    expects it to be initialized to something other than zero.
    Therefore, the source address sockaddr field should be fully
    initialized at transport create time in _every_ case, not just when
    the RPC application wants to use a specific bind address.
    Bruce added a workaround for this missing initialization by adjusting
    commit 6bc9638a, but the "right" way to do this is to ensure that the
    source address sockaddr is always correctly initialized from the
    This patch doesn't introduce a behavior change.  It's simply a
    clean-up of Bruce's fix, to prevent future problems of this kind.  It
    may look like overkill, but
      a) it clearly documents the default initial value of this field,
      b) it doesn't assume that the sockaddr_storage memory is first
         initialized to any particular value, and
      c) it will fail verbosely if some unknown address family is passed
    Originally introduced by commit d3bc9a1d.
    Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
    Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
xprtsock.c 65.3 KB