From: Roy Marples <roy@marples.name>
Date: Mon, 1 Feb 2016 22:16:26 +0000 (+0000)
Subject: Fix a crash where existing routes dhcpcd wants to parse have an ip address
X-Git-Tag: v6.10.2~85
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ce7c86d7ecf006d4b71c215d2bea2e91f6d9271;p=thirdparty%2Fdhcpcd.git

Fix a crash where existing routes dhcpcd wants to parse have an ip address
as a gateway.
Thanks to Christos Zoulas.
---

diff --git a/if-bsd.c b/if-bsd.c
index 9f63a345..91006376 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -463,6 +463,8 @@ if_copyrt(struct dhcpcd_ctx *ctx, struct rt *rt, struct rt_msghdr *rtm)
 	char *cp;
 	struct sockaddr *sa, *rti_info[RTAX_MAX];
 	struct sockaddr_dl *sdl;
+	struct sockaddr_in *sin;
+	struct ipv4_addr *ia;
 
 	cp = (char *)(void *)(rtm + 1);
 	sa = (struct sockaddr *)(void *)cp;
@@ -501,9 +503,22 @@ if_copyrt(struct dhcpcd_ctx *ctx, struct rt *rt, struct rt_msghdr *rtm)
 		sdl = (struct sockaddr_dl *)(void *)rti_info[RTAX_IFP];
 		rt->iface = if_findsdl(ctx, sdl);
 	} else if (rtm->rtm_addrs & RTA_GATEWAY) {
-		sdl = (struct sockaddr_dl *)(void *)rti_info[RTAX_GATEWAY];
-		if (sdl->sdl_family == AF_LINK)
+		sa = rti_info[RTAX_GATEWAY];
+		switch (sa->sa_family) {
+		case AF_LINK:
+			sdl = (void *)sa;
 			rt->iface = if_findsdl(ctx, sdl);
+			break;
+		case AF_INET:
+			sin = (void *)sa;
+			if ((ia = ipv4_findmaskaddr(ctx, &sin->sin_addr)))
+				rt->iface = ia->iface;
+			break;
+		default:
+			errno = EAFNOSUPPORT;
+			logger(ctx, LOG_ERR, "%s: %m", __func__);
+			return -1;
+		}
 	}
 
 	/* If we don't have an interface and it's a host route, it maybe
@@ -511,8 +526,6 @@ if_copyrt(struct dhcpcd_ctx *ctx, struct rt *rt, struct rt_msghdr *rtm)
 	if (rt->iface == NULL &&
 	    !(~rtm->rtm_flags & (RTF_HOST | RTF_GATEWAY)))
 	{
-		struct ipv4_addr *ia;
-
 		if ((ia = ipv4_findaddr(ctx, &rt->dest)))
 			rt->iface = ia->iface;
 	}
diff --git a/ipv4.c b/ipv4.c
index 50de28f0..35572230 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -145,6 +145,23 @@ ipv4_iffindlladdr(struct interface *ifp)
 	return NULL;
 }
 
+static struct ipv4_addr *
+ipv4_iffindmaskaddr(struct interface *ifp, const struct in_addr *addr)
+{
+	struct ipv4_state *state;
+	struct ipv4_addr *ap;
+
+	state = IPV4_STATE(ifp);
+	if (state) {
+		TAILQ_FOREACH (ap, &state->addrs, next) {
+			if ((ap->addr.s_addr & ap->net.s_addr) ==
+			    (addr->s_addr & ap->net.s_addr))
+				return ap;
+		}
+	}
+	return NULL;
+}
+
 struct ipv4_addr *
 ipv4_findaddr(struct dhcpcd_ctx *ctx, const struct in_addr *addr)
 {
@@ -159,6 +176,20 @@ ipv4_findaddr(struct dhcpcd_ctx *ctx, const struct in_addr *addr)
 	return NULL;
 }
 
+struct ipv4_addr *
+ipv4_findmaskaddr(struct dhcpcd_ctx *ctx, const struct in_addr *addr)
+{
+	struct interface *ifp;
+	struct ipv4_addr *ap;
+
+	TAILQ_FOREACH(ifp, ctx->ifaces, next) {
+		ap = ipv4_iffindmaskaddr(ifp, addr);
+		if (ap)
+			return ap;
+	}
+	return NULL;
+}
+
 int
 ipv4_srcaddr(const struct rt *rt, struct in_addr *addr)
 {
diff --git a/ipv4.h b/ipv4.h
index 0d3f838d..138c43f9 100644
--- a/ipv4.h
+++ b/ipv4.h
@@ -121,6 +121,8 @@ struct ipv4_addr *ipv4_iffindaddr(struct interface *,
     const struct in_addr *, const struct in_addr *);
 struct ipv4_addr *ipv4_iffindlladdr(struct interface *);
 struct ipv4_addr *ipv4_findaddr(struct dhcpcd_ctx *, const struct in_addr *);
+struct ipv4_addr *ipv4_findmaskaddr(struct dhcpcd_ctx *,
+    const struct in_addr *);
 int ipv4_srcaddr(const struct rt *, struct in_addr *);
 void ipv4_handleifa(struct dhcpcd_ctx *, int, struct if_head *, const char *,
     const struct in_addr *, const struct in_addr *, const struct in_addr *,