- Make ip_rtaddr() global, and use it to look up the correct source

  address in icmp_reflect().
- Two new "struct icmpstat" members: icps_badaddr and icps_noroute.

PR:		kern/31575
Obtained from:	BSD/OS
MFC after:	1 week

5 files changed, 40 insertions, 42 deletions

diff --git a/sys/netinet/icmp_var.h b/sys/netinet/icmp_var.h
index 814e932..4038c42 100644
--- a/sys/netinet/icmp_var.h
+++ b/sys/netinet/icmp_var.h
@@ -57,6 +57,8 @@ struct	icmpstat {
 	u_long	icps_inhist[ICMP_MAXTYPE + 1];
 	u_long	icps_bmcastecho; 	/* b/mcast echo requests dropped */
 	u_long	icps_bmcasttstamp; 	/* b/mcast tstamp requests dropped */
+	u_long	icps_badaddr;		/* bad return address */
+	u_long	icps_noroute; 		/* no route back */
 };
 
 /*
diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c
index 62bcd7e..dba581f 100644
--- a/sys/netinet/ip_icmp.c
+++ b/sys/netinet/ip_icmp.c
@@ -109,7 +109,7 @@ int	icmpprintfs = 0;
 #endif
 
 static void	icmp_reflect __P((struct mbuf *));
-static void	icmp_send __P((struct mbuf *, struct mbuf *));
+static void	icmp_send __P((struct mbuf *, struct mbuf *, struct route *));
 static int	ip_next_mtu __P((int, int));
 
 extern	struct protosw inetsw[];
@@ -589,11 +589,13 @@ icmp_reflect(m)
 	struct in_addr t;
 	struct mbuf *opts = 0;
 	int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
+	struct route *ro = NULL, rt;
 
 	if (!in_canforward(ip->ip_src) &&
 	    ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
 	     (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
 		m_freem(m);	/* Bad return address */
+		icmpstat.icps_badaddr++;
 		goto done;	/* Ip_output() will check for broadcast */
 	}
 	t = ip->ip_dst;
@@ -618,26 +620,13 @@ icmp_reflect(m)
                                 goto match;
         	}
         }
-	icmpdst.sin_addr = t;
-	ia = (struct in_ifaddr *)ifaof_ifpforaddr(
-	    (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
-	/*
-	 * The following happens if the packet was not addressed to us,
-	 * and was received on an interface with no IP address:
-	 * We find the first AF_INET address on the first non-loopback
-	 * interface.
-	 */
-	if (ia == NULL)
-		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
-			if ((ia->ia_ifp->if_flags & IFF_LOOPBACK) == 0)
-				break;
-
-	/*
-	 * If we still didn't find an address, punt.  We could have an
-	 * interface up and (and receiving packets) with no address.
-	 */
+	ro = &rt;
+	bzero(ro, sizeof(*ro));
+	ia = ip_rtaddr(ip->ip_dst, ro);
+	/* We need a route to do anything useful. */
 	if (ia == NULL) {
 		m_freem(m);
+		icmpstat.icps_noroute++;
 		goto done;
 	}
 match:
@@ -718,10 +707,12 @@ match:
 			 (unsigned)(m->m_len - sizeof(struct ip)));
 	}
 	m->m_flags &= ~(M_BCAST|M_MCAST);
-	icmp_send(m, opts);
+	icmp_send(m, opts, ro);
 done:
 	if (opts)
 		(void)m_free(opts);
+	if (ro && ro->ro_rt)
+		RTFREE(ro->ro_rt);
 }
 
 /*
@@ -729,14 +720,14 @@ done:
  * after supplying a checksum.
  */
 static void
-icmp_send(m, opts)
+icmp_send(m, opts, rt)
 	register struct mbuf *m;
 	struct mbuf *opts;
+	struct route *rt;
 {
 	register struct ip *ip = mtod(m, struct ip *);
 	register int hlen;
 	register struct icmp *icp;
-	struct route ro;
 
 	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 	m->m_data += hlen;
@@ -755,10 +746,7 @@ icmp_send(m, opts)
 		       buf, inet_ntoa(ip->ip_src));
 	}
 #endif
-	bzero(&ro, sizeof ro);
-	(void) ip_output(m, opts, &ro, 0, NULL);
-	if (ro.ro_rt)
-		RTFREE(ro.ro_rt);
+	(void) ip_output(m, opts, rt, 0, NULL);
 }
 
 n_time
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 17e3103..475b837 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -219,7 +219,6 @@ static struct	mbuf *ip_reass __P((struct mbuf *, struct ipqhead *, struct ipq *,
 #else
 static struct	mbuf *ip_reass __P((struct mbuf *, struct ipqhead *, struct ipq *));
 #endif
-static struct	in_ifaddr *ip_rtaddr __P((struct in_addr));
 static void	ipintr __P((void));
 
 /*
@@ -1273,7 +1272,7 @@ nosourcerouting:
 			    if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
 				ia = (INA)ifa_ifwithnet((SA)&ipaddr);
 			} else
-				ia = ip_rtaddr(ipaddr.sin_addr);
+				ia = ip_rtaddr(ipaddr.sin_addr, &ipforward_rt);
 			if (ia == 0) {
 				type = ICMP_UNREACH;
 				code = ICMP_UNREACH_SRCFAIL;
@@ -1311,7 +1310,8 @@ nosourcerouting:
 			 * use the incoming interface (should be same).
 			 */
 			if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
-			    (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
+			    (ia = ip_rtaddr(ipaddr.sin_addr,
+			    &ipforward_rt)) == 0) {
 				type = ICMP_UNREACH;
 				code = ICMP_UNREACH_HOST;
 				goto bad;
@@ -1399,30 +1399,31 @@ bad:
  * Given address of next destination (final or next hop),
  * return internet address info of interface to be used to get there.
  */
-static struct in_ifaddr *
-ip_rtaddr(dst)
-	 struct in_addr dst;
+struct in_ifaddr *
+ip_rtaddr(dst, rt)
+	struct in_addr dst;
+	struct route *rt;
 {
 	register struct sockaddr_in *sin;
 
-	sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
+	sin = (struct sockaddr_in *)&rt->ro_dst;
 
-	if (ipforward_rt.ro_rt == 0 ||
-	    !(ipforward_rt.ro_rt->rt_flags & RTF_UP) ||
+	if (rt->ro_rt == 0 ||
+	    !(rt->ro_rt->rt_flags & RTF_UP) ||
 	    dst.s_addr != sin->sin_addr.s_addr) {
-		if (ipforward_rt.ro_rt) {
-			RTFREE(ipforward_rt.ro_rt);
-			ipforward_rt.ro_rt = 0;
+		if (rt->ro_rt) {
+			RTFREE(rt->ro_rt);
+			rt->ro_rt = 0;
 		}
 		sin->sin_family = AF_INET;
 		sin->sin_len = sizeof(*sin);
 		sin->sin_addr = dst;
 
-		rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
+		rtalloc_ign(rt, RTF_PRCLONING);
 	}
-	if (ipforward_rt.ro_rt == 0)
+	if (rt->ro_rt == 0)
 		return ((struct in_ifaddr *)0);
-	return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
+	return (ifatoia(rt->ro_rt->rt_ifa));
 }
 
 /*
@@ -1608,7 +1609,7 @@ ip_forward(m, srcrt)
 	}
 #endif
 
-	if (ip_rtaddr(ip->ip_dst) == 0) {
+	if (ip_rtaddr(ip->ip_dst, &ipforward_rt) == 0) {
 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
 		return;
 	} else
diff --git a/sys/netinet/ip_var.h b/sys/netinet/ip_var.h
index 2a84b38..d8f7a0b 100644
--- a/sys/netinet/ip_var.h
+++ b/sys/netinet/ip_var.h
@@ -164,6 +164,8 @@ extern int	 (*ip_mforward) __P((struct ip *, struct ifnet *, struct mbuf *,
 			  struct ip_moptions *));
 int	 ip_output __P((struct mbuf *,
 	    struct mbuf *, struct route *, int, struct ip_moptions *));
+struct in_ifaddr *
+	 ip_rtaddr __P((struct in_addr, struct route *));
 void	 ip_savecontrol __P((struct inpcb *, struct mbuf **, struct ip *,
 		struct mbuf *));
 void	 ip_slowtimo __P((void));
diff --git a/usr.bin/netstat/inet.c b/usr.bin/netstat/inet.c
index beb227e..b95bad7 100644
--- a/usr.bin/netstat/inet.c
+++ b/usr.bin/netstat/inet.c
@@ -624,6 +624,8 @@ icmp_stats(u_long off __unused, char *name, int af __unused)
     printf(m, icmpstat.f, plural(icmpstat.f))
 #define	p1a(f, m) if (icmpstat.f || sflag <= 1) \
     printf(m, icmpstat.f)
+#define	p2(f, m) if (icmpstat.f || sflag <= 1) \
+    printf(m, icmpstat.f, plurales(icmpstat.f))
 
 	p(icps_error, "\t%lu call%s to icmp_error\n");
 	p(icps_oldicmp,
@@ -653,8 +655,11 @@ icmp_stats(u_long off __unused, char *name, int af __unused)
 				icmpstat.icps_inhist[i]);
 		}
 	p(icps_reflect, "\t%lu message response%s generated\n");
+	p2(icps_badaddr, "\t%lu invalid return address%s\n");
+	p(icps_badaddr, "\t%lu no return route%s\n");
 #undef p
 #undef p1a
+#undef p2
 	mib[3] = ICMPCTL_MASKREPL;
 	len = sizeof i;
 	if (sysctl(mib, 4, &i, &len, (void *)0, 0) < 0)