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Differential D19594 Diff 56536 head/sys/netinet/udp_usrreq.c

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head/sys/netinet/udp_usrreq.c

Show First 20 Lines • Show All 1,252 Lines • ▼ Show 20 Lines if (unlock_inp == UH_WLOCKED)
INP_WUNLOCK(inp); INP_WUNLOCK(inp);
else else
INP_RUNLOCK(inp); INP_RUNLOCK(inp);
m_freem(m); m_freem(m);
return (error); return (error);
} }
/* /*
* Depending on whether or not the application has bound or connected * In the old days, depending on whether or not the application had
* the socket, we may have to do varying levels of work. The optimal * bound or connected the socket, we had to do varying levels of work.
* case is for a connected UDP socket, as a global lock isn't * The optimal case was for a connected UDP socket, as a global lock
* required at all. * wasn't required at all.
* * In order to decide which we need, we required stability of the
* In order to decide which we need, we require stability of the * inpcb binding, which we ensured by acquiring a read lock on the
* inpcb binding, which we ensure by acquiring a read lock on the * inpcb. This didn't strictly follow the lock order, so we played
* inpcb. This doesn't strictly follow the lock order, so we play * the trylock and retry game.
* the trylock and retry game; note that we may end up with more * With the re-introduction of the route-cache in some cases, we started
* conservative locks than required the second time around, so later * to acquire an early inp wlock and a possible race during re-lock
* assertions have to accept that. Further analysis of the number of * went away. With the introduction of epoch(9) some read locking
* misses under contention is required. * became epoch(9) and the lock-order issues also went away.
* * Due to route-cache we may now hold more conservative locks than
* XXXRW: Check that hash locking update here is correct. * otherwise required and have split up the 2nd case in case 2 and 3
* in order to keep the udpinfo lock level in sync with the inp one
* for the IP_SENDSRCADDR case below.
*/ */
pr = inp->inp_socket->so_proto->pr_protocol; pr = inp->inp_socket->so_proto->pr_protocol;
pcbinfo = udp_get_inpcbinfo(pr); pcbinfo = udp_get_inpcbinfo(pr);
if (sin != NULL && if (sin != NULL &&
(inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) { (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
INP_HASH_WLOCK(pcbinfo); INP_HASH_WLOCK(pcbinfo);
unlock_udbinfo = UH_WLOCKED; unlock_udbinfo = UH_WLOCKED;
} else if ((sin != NULL && } else if (sin != NULL &&
(sin->sin_addr.s_addr == INADDR_ANY || (sin->sin_addr.s_addr == INADDR_ANY ||
sin->sin_addr.s_addr == INADDR_BROADCAST || sin->sin_addr.s_addr == INADDR_BROADCAST ||
inp->inp_laddr.s_addr == INADDR_ANY || inp->inp_laddr.s_addr == INADDR_ANY ||
inp->inp_lport == 0)) || inp->inp_lport == 0)) {
src.sin_family == AF_INET) {
INP_HASH_RLOCK_ET(pcbinfo, et); INP_HASH_RLOCK_ET(pcbinfo, et);
unlock_udbinfo = UH_RLOCKED; unlock_udbinfo = UH_RLOCKED;
} else if (src.sin_family == AF_INET) {
if (unlock_inp == UH_WLOCKED) {
INP_HASH_WLOCK(pcbinfo);
unlock_udbinfo = UH_WLOCKED;
} else {
INP_HASH_RLOCK_ET(pcbinfo, et);
unlock_udbinfo = UH_RLOCKED;
}
} else } else
unlock_udbinfo = UH_UNLOCKED; unlock_udbinfo = UH_UNLOCKED;
/* /*
* If the IP_SENDSRCADDR control message was specified, override the * If the IP_SENDSRCADDR control message was specified, override the
* source address for this datagram. Its use is invalidated if the * source address for this datagram. Its use is invalidated if the
* address thus specified is incomplete or clobbers other inpcbs. * address thus specified is incomplete or clobbers other inpcbs.
*/ */
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