Index | Thread | Search

From:
Alexander Bluhm <alexander.bluhm@gmx.net>
Subject:
route cache return hit or miss
To:
tech@openbsd.org
Date:
Thu, 8 Feb 2024 23:15:40 +0100

Download raw body.

Thread
Hi,

The route_cache() function can easily return whether it was a cache
hit or miss.  Then the logic to perform a route lookup gets a bit
simpler.  Some more complicated if (ro->ro_rt == NULL) checks still
exist elsewhere.

Also use route cache in in_pcbselsrc() instead of filling struct
route manually.

ok?

bluhm

Index: net/route.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/net/route.c,v
diff -u -p -r1.430 route.c
--- net/route.c	7 Feb 2024 23:52:20 -0000	1.430
+++ net/route.c	8 Feb 2024 14:43:01 -0000
@@ -201,7 +201,7 @@ route_init(void)
 #endif
 }
 
-void
+int
 route_cache(struct route *ro, struct in_addr addr, u_int rtableid)
 {
 	u_long gen;
@@ -215,7 +215,7 @@ route_cache(struct route *ro, struct in_
 	    ro->ro_dst.sa_family == AF_INET &&
 	    satosin(&ro->ro_dst)->sin_addr.s_addr == addr.s_addr) {
 		ipstat_inc(ips_rtcachehit);
-		return;
+		return (0);
 	}
 
 	ipstat_inc(ips_rtcachemiss);
@@ -228,10 +228,12 @@ route_cache(struct route *ro, struct in_
 	satosin(&ro->ro_dst)->sin_family = AF_INET;
 	satosin(&ro->ro_dst)->sin_len = sizeof(struct sockaddr_in);
 	satosin(&ro->ro_dst)->sin_addr = addr;
+
+	return (ESRCH);
 }
 
 #ifdef INET6
-void
+int
 route6_cache(struct route_in6 *ro, const struct in6_addr *addr,
     u_int rtableid)
 {
@@ -246,7 +248,7 @@ route6_cache(struct route_in6 *ro, const
 	    ro->ro_dst.sin6_family == AF_INET6 &&
 	    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, addr)) {
 		ip6stat_inc(ip6s_rtcachehit);
-		return;
+		return (0);
 	}
 
 	ip6stat_inc(ip6s_rtcachemiss);
@@ -259,6 +261,8 @@ route6_cache(struct route_in6 *ro, const
 	ro->ro_dst.sin6_family = AF_INET6;
 	ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
 	ro->ro_dst.sin6_addr = *addr;
+
+	return (ESRCH);
 }
 #endif
 
Index: netinet/in.h
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in.h,v
diff -u -p -r1.146 in.h
--- netinet/in.h	5 Feb 2024 12:52:11 -0000	1.146
+++ netinet/in.h	8 Feb 2024 14:37:42 -0000
@@ -789,7 +789,7 @@ void	   in_len2mask(struct in_addr *, in
 int	   in_nam2sin(const struct mbuf *, struct sockaddr_in **);
 int	   in_sa2sin(struct sockaddr *, struct sockaddr_in **);
 
-void	   route_cache(struct route *, struct in_addr, u_int);
+int	   route_cache(struct route *, struct in_addr, u_int);
 
 char	  *inet_ntoa(struct in_addr);
 int	   inet_nat64(int, const void *, void *, const void *, u_int8_t);
Index: netinet/in_pcb.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in_pcb.c,v
diff -u -p -r1.290 in_pcb.c
--- netinet/in_pcb.c	7 Feb 2024 23:40:40 -0000	1.290
+++ netinet/in_pcb.c	8 Feb 2024 14:44:49 -0000
@@ -918,8 +918,7 @@ in_pcbrtentry(struct inpcb *inp)
 
 	if (inp->inp_faddr.s_addr == INADDR_ANY)
 		return (NULL);
-	route_cache(ro, inp->inp_faddr, inp->inp_rtableid);
-	if (ro->ro_rt == NULL) {
+	if (route_cache(ro, inp->inp_faddr, inp->inp_rtableid)) {
 		ro->ro_rt = rtalloc_mpath(&ro->ro_dst,
 		    &inp->inp_laddr.s_addr, ro->ro_tableid);
 	}
@@ -941,8 +940,6 @@ in_pcbselsrc(struct in_addr *insrc, stru
 	const struct in_addr *laddr = &inp->inp_laddr;
 	u_int rtableid = inp->inp_rtableid;
 	struct sockaddr	*ip4_source = NULL;
-
-	struct sockaddr_in *sin2;
 	struct in_ifaddr *ia = NULL;
 
 	/*
@@ -984,25 +981,9 @@ in_pcbselsrc(struct in_addr *insrc, stru
 	 * If route is known or can be allocated now,
 	 * our src addr is taken from the i/f, else punt.
 	 */
-	if (!rtisvalid(ro->ro_rt) || (ro->ro_tableid != rtableid) ||
-	    (satosin(&ro->ro_dst)->sin_addr.s_addr != sin->sin_addr.s_addr)) {
-		rtfree(ro->ro_rt);
-		ro->ro_rt = NULL;
-	}
-	if (ro->ro_rt == NULL) {
+	if (route_cache(ro, sin->sin_addr, rtableid)) {
 		/* No route yet, so try to acquire one */
-		ro->ro_dst.sa_family = AF_INET;
-		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
-		satosin(&ro->ro_dst)->sin_addr = sin->sin_addr;
-		ro->ro_tableid = rtableid;
 		ro->ro_rt = rtalloc_mpath(&ro->ro_dst, NULL, ro->ro_tableid);
-
-		/*
-		 * It is important to zero out the rest of the
-		 * struct sockaddr_in when mixing v6 & v4!
-		 */
-		sin2 = satosin(&ro->ro_dst);
-		memset(sin2->sin_zero, 0, sizeof(sin2->sin_zero));
 	}
 
 	/*
Index: netinet6/in6.h
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/in6.h,v
diff -u -p -r1.114 in6.h
--- netinet6/in6.h	7 Feb 2024 23:40:40 -0000	1.114
+++ netinet6/in6.h	8 Feb 2024 14:38:13 -0000
@@ -428,7 +428,7 @@ int	in6_mask2len(struct in6_addr *, u_ch
 int	in6_nam2sin6(const struct mbuf *, struct sockaddr_in6 **);
 int	in6_sa2sin6(struct sockaddr *, struct sockaddr_in6 **);
 
-void	route6_cache(struct route_in6 *, const struct in6_addr *, u_int);
+int	route6_cache(struct route_in6 *, const struct in6_addr *, u_int);
 
 struct ip6_pktopts;
 struct ip6_moptions;
Index: netinet6/in6_pcb.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/in6_pcb.c,v
diff -u -p -r1.135 in6_pcb.c
--- netinet6/in6_pcb.c	7 Feb 2024 23:40:40 -0000	1.135
+++ netinet6/in6_pcb.c	8 Feb 2024 14:47:09 -0000
@@ -568,8 +568,7 @@ in6_pcbrtentry(struct inpcb *inp)
 
 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
 		return (NULL);
-	route6_cache(ro, &inp->inp_faddr6, inp->inp_rtableid);
-	if (ro->ro_rt == NULL) {
+	if (route6_cache(ro, &inp->inp_faddr6, inp->inp_rtableid)) {
 		ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst),
 		    &inp->inp_laddr6.s6_addr32[0], ro->ro_tableid);
 	}
Index: netinet6/in6_src.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/in6_src.c,v
diff -u -p -r1.92 in6_src.c
--- netinet6/in6_src.c	7 Feb 2024 23:40:40 -0000	1.92
+++ netinet6/in6_src.c	8 Feb 2024 14:48:05 -0000
@@ -179,8 +179,7 @@ in6_pcbselsrc(const struct in6_addr **in
 	 * If route is known or can be allocated now,
 	 * our src addr is taken from the i/f, else punt.
 	 */
-	route6_cache(ro, dst, rtableid);
-	if (ro->ro_rt == NULL) {
+	if (route6_cache(ro, dst, rtableid)) {
 		ro->ro_rt = rtalloc(sin6tosa(&ro->ro_dst),
 		    RT_RESOLVE, ro->ro_tableid);
 	}
@@ -306,8 +305,7 @@ in6_selectroute(const struct in6_addr *d
 	 * a new one.
 	 */
 	if (ro) {
-		route6_cache(ro, dst, rtableid);
-		if (ro->ro_rt == NULL) {
+		if (route6_cache(ro, dst, rtableid)) {
 			/* No route yet, so try to acquire one */
 			ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst),
 			    NULL, ro->ro_tableid);