diff options
Diffstat (limited to 'sys/kern/uipc_socket.c')
| -rw-r--r-- | sys/kern/uipc_socket.c | 56 |
1 files changed, 42 insertions, 14 deletions
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c index 8e34acdb9502..fbf0d5330b5a 100644 --- a/sys/kern/uipc_socket.c +++ b/sys/kern/uipc_socket.c @@ -1,6 +1,6 @@ /*- * Copyright (c) 2004 The FreeBSD Foundation - * Copyright (c) 2004-2005 Robert Watson + * Copyright (c) 2004-2005 Robert N. M. Watson * Copyright (c) 1982, 1986, 1988, 1990, 1993 * The Regents of the University of California. All rights reserved. * @@ -271,6 +271,18 @@ sodealloc(struct socket *so) mtx_unlock(&so_global_mtx); } +/* + * solisten() transitions a socket from a non-listening state to a listening + * state, but can also be used to update the listen queue depth on an + * existing listen socket. The protocol will call back into the sockets + * layer using solisten_proto_check() and solisten_proto() to check and set + * socket-layer listen state. Call backs are used so that the protocol can + * acquire both protocol and socket layer locks in whatever order is reuiqred + * by the protocol. + * + * Protocol implementors are advised to hold the socket lock across the + * socket-layer test and set to avoid races at the socket layer. + */ int solisten(so, backlog, td) struct socket *so; @@ -279,28 +291,44 @@ solisten(so, backlog, td) { int error; - /* - * XXXRW: Ordering issue here -- perhaps we need to set - * SO_ACCEPTCONN before the call to pru_listen()? - * XXXRW: General atomic test-and-set concerns here also. - */ - if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING | - SS_ISDISCONNECTING)) - return (EINVAL); error = (*so->so_proto->pr_usrreqs->pru_listen)(so, td); if (error) return (error); - ACCEPT_LOCK(); - SOCK_LOCK(so); - so->so_options |= SO_ACCEPTCONN; - SOCK_UNLOCK(so); + + /* + * XXXRW: The following state adjustment should occur in + * solisten_proto(), but we don't currently pass the backlog request + * to the protocol via pru_listen(). + */ if (backlog < 0 || backlog > somaxconn) backlog = somaxconn; so->so_qlimit = backlog; - ACCEPT_UNLOCK(); return (0); } +int +solisten_proto_check(so) + struct socket *so; +{ + + SOCK_LOCK_ASSERT(so); + + if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING | + SS_ISDISCONNECTING)) + return (EINVAL); + return (0); +} + +void +solisten_proto(so) + struct socket *so; +{ + + SOCK_LOCK_ASSERT(so); + + so->so_options |= SO_ACCEPTCONN; +} + /* * Attempt to free a socket. This should really be sotryfree(). * |