Explicitly request the sockaddr_dl when doing a RTM_GET rather than

assuming that it will be in the gateway sa.

Fixes a regression introduced with the support of multiple connected
routes, found the hardway by deraadt@.

ok claudio@

diff --git a/usr.sbin/arp/arp.c b/usr.sbin/arp/arp.c
index fcd6149..e2d36cd 100644 (file)
--- a/usr.sbin/arp/arp.c
+++ b/usr.sbin/arp/arp.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: arp.c,v 1.63 2015/01/16 06:40:15 deraadt Exp $ */
+/*     $OpenBSD: arp.c,v 1.64 2015/06/03 08:10:53 mpi Exp $ */
 /*     $NetBSD: arp.c,v 1.12 1995/04/24 13:25:18 cgd Exp $ */
 
 /*
@@ -75,6 +75,7 @@ int file(char *);
 int get(const char *);
 int getinetaddr(const char *, struct in_addr *);
 void getsocket(void);
+int rtget(struct sockaddr_inarp **, struct sockaddr_dl **);
 int rtmsg(int);
 int set(int, char **);
 void usage(void);
@@ -254,6 +255,7 @@ getsocket(void)
 struct sockaddr_in     so_mask = { 8, 0, 0, { 0xffffffff } };
 struct sockaddr_inarp  blank_sin = { sizeof(blank_sin), AF_INET }, sin_m;
 struct sockaddr_dl     blank_sdl = { sizeof(blank_sdl), AF_LINK }, sdl_m;
+struct sockaddr_dl     ifp_m = { sizeof(&ifp_m), AF_LINK };
 time_t                 expire_time;
 int                    flags, export_only, doing_proxy, found_entry;
 struct {
@@ -319,12 +321,11 @@ set(int argc, char *argv[])
        }
 
 tryagain:
-       if (rtmsg(RTM_GET) < 0) {
+       if (rtget(&sin, &sdl)) {
                warn("%s", host);
                return (1);
        }
-       sin = (struct sockaddr_inarp *)((char *)rtm + rtm->rtm_hdrlen);
-       sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin_len) + (char *)sin);
+
        if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
                if (sdl->sdl_family == AF_LINK &&
                    (rtm->rtm_flags & RTF_LLINFO) &&
@@ -412,15 +413,13 @@ delete(const char *host, const char *info)
        if (getinetaddr(host, &sin->sin_addr) == -1)
                return (1);
 tryagain:
-       if (rtmsg(RTM_GET) < 0) {
+       if (rtget(&sin, &sdl) < 0) {
                warn("%s", host);
                return (1);
        }
-       sin = (struct sockaddr_inarp *)((char *)rtm + rtm->rtm_hdrlen);
-       sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin_len) + (char *)sin);
        if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
                if (sdl->sdl_family == AF_LINK && rtm->rtm_flags & RTF_LLINFO) {
-                       if (rtm->rtm_flags & (RTF_LOCAL|RTF_BROADCAST))
+                       if (rtm->rtm_flags & RTF_LOCAL)
                                return (0);
                        if (!(rtm->rtm_flags & RTF_GATEWAY))
                                switch (sdl->sdl_type) {
@@ -493,8 +492,6 @@ search(in_addr_t addr, void (*action)(struct sockaddr_dl *sdl,
                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
-               if (rtm->rtm_flags & RTF_BROADCAST)
-                       continue;
                sin = (struct sockaddr_inarp *)(next + rtm->rtm_hdrlen);
                sdl = (struct sockaddr_dl *)(sin + 1);
                if (addr) {
@@ -558,7 +555,7 @@ print_entry(struct sockaddr_dl *sdl, struct sockaddr_inarp *sin,
        printf("%-*.*s %-*.*s %*.*s", addrwidth, addrwidth, host,
            llwidth, llwidth, ether_str(sdl), ifwidth, ifwidth, ifname);
 
-       if (rtm->rtm_flags & (RTF_PERMANENT_ARP|RTF_LOCAL|RTF_BROADCAST))
+       if (rtm->rtm_flags & (RTF_PERMANENT_ARP|RTF_LOCAL))
                printf(" %-10.10s", "permanent");
        else if (rtm->rtm_rmx.rmx_expire == 0)
                printf(" %-10.10s", "static");
@@ -654,7 +651,7 @@ rtmsg(int cmd)
                }
                /* FALLTHROUGH */
        case RTM_GET:
-               rtm->rtm_addrs |= RTA_DST;
+               rtm->rtm_addrs |= (RTA_DST | RTA_IFP);
        }
 
 #define NEXTADDR(w, s)                                 \
@@ -666,6 +663,7 @@ rtmsg(int cmd)
        NEXTADDR(RTA_DST, sin_m);
        NEXTADDR(RTA_GATEWAY, sdl_m);
        NEXTADDR(RTA_NETMASK, so_mask);
+       NEXTADDR(RTA_IFP, ifp_m);
 
        rtm->rtm_msglen = cp - (char *)&m_rtmsg;
 doit:
@@ -688,6 +686,48 @@ doit:
        return (0);
 }
 
+int
+rtget(struct sockaddr_inarp **sinp, struct sockaddr_dl **sdlp)
+{
+       struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
+       struct sockaddr_inarp *sin = NULL;
+       struct sockaddr_dl *sdl = NULL;
+       struct sockaddr *sa;
+       char *cp;
+       int i;
+
+       if (rtmsg(RTM_GET) < 0)
+               return (1);
+
+       if (rtm->rtm_addrs) {
+               cp = ((char *)rtm + rtm->rtm_hdrlen);
+               for (i = 1; i; i <<= 1) {
+                       if (i & rtm->rtm_addrs) {
+                               sa = (struct sockaddr *)cp;
+                               switch (i) {
+                               case RTA_DST:
+                                       sin = (struct sockaddr_inarp *)sa;
+                                       break;
+                               case RTA_IFP:
+                                       sdl = (struct sockaddr_dl *)sa;
+                                       break;
+                               default:
+                                       break;
+                               }
+                               cp += ROUNDUP(sa->sa_len);
+                       }
+               }
+       }
+
+       if (sin == NULL || sdl == NULL)
+               return (1);
+
+       *sinp = sin;
+       *sdlp = sdl;
+
+       return (0);
+}
+
 int
 getinetaddr(const char *host, struct in_addr *inap)
 {

diff --git a/usr.sbin/ndp/ndp.c b/usr.sbin/ndp/ndp.c
index ce75ef7..46c1269 100644 (file)
--- a/usr.sbin/ndp/ndp.c
+++ b/usr.sbin/ndp/ndp.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ndp.c,v 1.60 2015/04/18 18:28:38 deraadt Exp $        */
+/*     $OpenBSD: ndp.c,v 1.61 2015/06/03 08:10:53 mpi Exp $    */
 /*     $KAME: ndp.c,v 1.101 2002/07/17 08:46:33 itojun Exp $   */
 
 /*
@@ -134,6 +134,7 @@ static char *ether_str(struct sockaddr_dl *);
 int ndp_ether_aton(char *, u_char *);
 void usage(void);
 int rtmsg(int);
+int rtget(struct sockaddr_in6 **, struct sockaddr_dl **);
 void ifinfo(char *, int, char **);
 void rtrlist(void);
 void plist(void);
@@ -343,6 +344,7 @@ getsocket(void)
 struct sockaddr_in6 so_mask = {sizeof(so_mask), AF_INET6 };
 struct sockaddr_in6 blank_sin = {sizeof(blank_sin), AF_INET6 }, sin_m;
 struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
+struct sockaddr_dl ifp_m = { sizeof(&ifp_m), AF_LINK };
 time_t expire_time;
 int    flags, found_entry;
 struct {
@@ -400,12 +402,12 @@ set(int argc, char **argv)
                        flags |= RTF_ANNOUNCE;
                argv++;
        }
-       if (rtmsg(RTM_GET) < 0) {
+
+       if (rtget(&sin, &sdl)) {
                errx(1, "RTM_GET(%s) failed", host);
                /* NOTREACHED */
        }
-       sin = (struct sockaddr_in6 *)((char *)rtm + rtm->rtm_hdrlen);
-       sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin6_len) + (char *)sin);
+
        if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr)) {
                if (sdl->sdl_family == AF_LINK &&
                    (rtm->rtm_flags & RTF_LLINFO) &&
@@ -499,12 +501,12 @@ delete(char *host)
                    htons(((struct sockaddr_in6 *)res->ai_addr)->sin6_scope_id);
        }
 #endif
-       if (rtmsg(RTM_GET) < 0) {
+
+       if (rtget(&sin, &sdl)) {
                errx(1, "RTM_GET(%s) failed", host);
                /* NOTREACHED */
        }
-       sin = (struct sockaddr_in6 *)((char *)rtm + rtm->rtm_hdrlen);
-       sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin6_len) + (char *)sin);
+
        if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr)) {
                if (sdl->sdl_family == AF_LINK && rtm->rtm_flags & RTF_LLINFO) {
                        if (rtm->rtm_flags & (RTF_LOCAL|RTF_BROADCAST))
@@ -832,7 +834,7 @@ rtmsg(int cmd)
 #endif
                /* FALLTHROUGH */
        case RTM_GET:
-               rtm->rtm_addrs |= RTA_DST;
+               rtm->rtm_addrs |= (RTA_DST | RTA_IFP);
        }
 #define NEXTADDR(w, s) \
        if (rtm->rtm_addrs & (w)) { \
@@ -844,6 +846,7 @@ rtmsg(int cmd)
        memset(&so_mask.sin6_addr, 0xff, sizeof(so_mask.sin6_addr));
        NEXTADDR(RTA_NETMASK, so_mask);
 #endif
+       NEXTADDR(RTA_IFP, ifp_m);
 
        rtm->rtm_msglen = cp - (char *)&m_rtmsg;
 doit:
@@ -866,6 +869,48 @@ doit:
        return (0);
 }
 
+int
+rtget(struct sockaddr_in6 **sinp, struct sockaddr_dl **sdlp)
+{
+       struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
+       struct sockaddr_in6 *sin = NULL;
+       struct sockaddr_dl *sdl = NULL;
+       struct sockaddr *sa;
+       char *cp;
+       int i;
+
+       if (rtmsg(RTM_GET) < 0)
+               return (1);
+
+       if (rtm->rtm_addrs) {
+               cp = ((char *)rtm + rtm->rtm_hdrlen);
+               for (i = 1; i; i <<= 1) {
+                       if (i & rtm->rtm_addrs) {
+                               sa = (struct sockaddr *)cp;
+                               switch (i) {
+                               case RTA_DST:
+                                       sin = (struct sockaddr_in6 *)sa;
+                                       break;
+                               case RTA_IFP:
+                                       sdl = (struct sockaddr_dl *)sa;
+                                       break;
+                               default:
+                                       break;
+                               }
+                               cp += ROUNDUP(sa->sa_len);
+                       }
+               }
+       }
+
+       if (sin == NULL || sdl == NULL)
+               return (1);
+
+       *sinp = sin;
+       *sdlp = sdl;
+
+       return (0);
+}
+
 void
 ifinfo(char *ifname, int argc, char **argv)
 {