From fdd9b0723ec178e5ac97e5ffb4dde526dcc353cb Mon Sep 17 00:00:00 2001
From: Robert Watson <rwatson@FreeBSD.org>
Date: Sun, 20 Apr 2008 00:21:54 +0000
Subject: [PATCH] Teach pf and ipfw to use read locks in inpcbs write than
 write locks when reading credential data from sockets.

Teach pf to unlock the pcbinfo more quickly once it has acquired an
inpcb lock, as the inpcb lock is sufficient to protect the reference.

Assert locks, rather than read locks or write locks, on inpcbs in
subroutines--this is necessary as the inpcb may be passed down with a
write lock from the protocol, or may be passed down with a read lock
from the firewall lookup routine, and either is sufficient.

MFC after:	3 months
---
 sys/contrib/pf/net/pf.c | 11 +++++------
 sys/netinet/ip_fw2.c    |  6 +++---
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/sys/contrib/pf/net/pf.c b/sys/contrib/pf/net/pf.c
index 69fe3de830f..96bf2de789e 100644
--- a/sys/contrib/pf/net/pf.c
+++ b/sys/contrib/pf/net/pf.c
@@ -2915,7 +2915,7 @@ pf_socket_lookup(int direction, struct pf_pdesc *pd)
 	pd->lookup.pid = NO_PID;		/* XXX: revisit */
 #ifdef __FreeBSD__
 	if (inp_arg != NULL) {
-		INP_WLOCK_ASSERT(inp_arg);
+		INP_LOCK_ASSERT(inp_arg);
 		if (inp_arg->inp_socket) {
 			pd->lookup.uid = inp_arg->inp_socket->so_cred->cr_uid;
 			pd->lookup.gid =
@@ -3018,16 +3018,15 @@ pf_socket_lookup(int direction, struct pf_pdesc *pd)
 		return (-1);
 	}
 #ifdef __FreeBSD__
-	INP_WLOCK(inp);
+	INP_RLOCK(inp);
+	INP_INFO_RUNLOCK(pi);
 	if ((inp->inp_socket == NULL) || (inp->inp_socket->so_cred == NULL)) {
-		INP_WUNLOCK(inp);
-		INP_INFO_RUNLOCK(pi);
+		INP_RUNLOCK(inp);
 		return (-1);
 	}
 	pd->lookup.uid = inp->inp_socket->so_cred->cr_uid;
 	pd->lookup.gid = inp->inp_socket->so_cred->cr_groups[0];
-	INP_WUNLOCK(inp);
-	INP_INFO_RUNLOCK(pi);
+	INP_RUNLOCK(inp);
 #else
 	pd->lookup.uid = inp->inp_socket->so_euid;
 	pd->lookup.gid = inp->inp_socket->so_egid;
diff --git a/sys/netinet/ip_fw2.c b/sys/netinet/ip_fw2.c
index 428a18249d7..39baa71ebce 100644
--- a/sys/netinet/ip_fw2.c
+++ b/sys/netinet/ip_fw2.c
@@ -1974,7 +1974,7 @@ check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif,
 	 * up the PCB, we can use the one that was supplied.
 	 */
 	if (inp && *lookup == 0) {
-		INP_WLOCK_ASSERT(inp);
+		INP_LOCK_ASSERT(inp);
 		if (inp->inp_socket != NULL) {
 			fill_ugid_cache(inp, ugp);
 			*lookup = 1;
@@ -2008,12 +2008,12 @@ check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif,
 				dst_ip, htons(dst_port),
 				wildcard, NULL);
 		if (pcb != NULL) {
-			INP_WLOCK(pcb);
+			INP_RLOCK(pcb);
 			if (pcb->inp_socket != NULL) {
 				fill_ugid_cache(pcb, ugp);
 				*lookup = 1;
 			}
-			INP_WUNLOCK(pcb);
+			INP_RUNLOCK(pcb);
 		}
 		INP_INFO_RUNLOCK(pi);
 		if (*lookup == 0) {