[src/trunk]: src/usr.sbin/pppd/pppd - skip addresses that don't have a link a...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/50f6806a84ea
branches:  trunk
changeset: 787229:50f6806a84ea
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Jun 07 17:17:14 2013 +0000

description:
- skip addresses that don't have a link address by finding the link address
  immediately.
- don't skip v6 only interfaces.
- default to the first interface with a link address or to the best matching
  one, printing a warning if there are more than one.
- consume data after sending messages to the routing socket.

diffstat:

 usr.sbin/pppd/pppd/sys-bsd.c |  180 +++++++++++++++++++++++++++++-------------
 1 files changed, 124 insertions(+), 56 deletions(-)

diffs (truncated from 306 to 300 lines):

diff -r 7a649db806c3 -r 50f6806a84ea usr.sbin/pppd/pppd/sys-bsd.c
--- a/usr.sbin/pppd/pppd/sys-bsd.c      Fri Jun 07 16:44:17 2013 +0000
+++ b/usr.sbin/pppd/pppd/sys-bsd.c      Fri Jun 07 17:17:14 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys-bsd.c,v 1.65 2011/09/24 20:19:39 christos Exp $    */
+/*     $NetBSD: sys-bsd.c,v 1.66 2013/06/07 17:17:14 christos Exp $    */
 
 /*
  * sys-bsd.c - System-dependent procedures for setting up
@@ -79,7 +79,7 @@
 #if 0
 #define RCSID  "Id: sys-bsd.c,v 1.47 2000/04/13 12:04:23 paulus Exp "
 #else
-__RCSID("$NetBSD: sys-bsd.c,v 1.65 2011/09/24 20:19:39 christos Exp $");
+__RCSID("$NetBSD: sys-bsd.c,v 1.66 2013/06/07 17:17:14 christos Exp $");
 #endif
 #endif
 
@@ -1540,6 +1540,27 @@
     return dodefaultroute(g, 'c');
 }
 
+#if RTM_VERSION >= 3
+static struct {
+    struct rt_msghdr           hdr;
+    char                       space[512];
+} arpmsg;
+
+static int arpmsg_valid;
+
+static void
+consume(int routes) {
+    ssize_t l;
+    pid_t pid = getpid();
+    struct rt_msghdr *rtm = &arpmsg.hdr;
+
+    do
+       l = read(routes, &arpmsg, sizeof(arpmsg));
+    while (l > 0 && (rtm->rtm_seq != rtm_seq || rtm->rtm_pid != pid));
+    if (l < 0)
+       warn("read from routing socket");
+}
+
 /*
  * dodefaultroute - talk to a routing socket to add/delete a default route.
  */
@@ -1555,7 +1576,7 @@
        struct sockaddr_dl      ifp;
     } rtmsg;
 
-    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
        if (!doing_cleanup)
            error("%s: Couldn't %s default route: socket: %m", __func__,
                cmd == 's' ? "add" : "delete");
@@ -1596,42 +1617,55 @@
        close(routes);
        return 0;
     }
+    consume(routes);
 
     close(routes);
     default_route_gateway = (cmd == 's') ? g : 0;
     return 1;
 }
 
-#if RTM_VERSION >= 3
+
+#if 0
+static void
+hdrprint(const struct rt_msghdr *rtm) {
+       printf("rtm_msglen=%u\n", rtm->rtm_msglen);
+       printf("rtm_version=%u\n", rtm->rtm_version);
+       printf("rtm_type=%u\n", rtm->rtm_type);
+       printf("rtm_index=%u\n", rtm->rtm_index);
+       printf("rtm_flags=%x\n", rtm->rtm_flags);
+       printf("rtm_addrs=%d\n", rtm->rtm_addrs);
+       printf("rtm_pid=%lu\n", (unsigned long)rtm->rtm_pid);
+       printf("rtm_seq=%d\n", rtm->rtm_seq);
+       printf("rtm_errno=%d\n", rtm->rtm_errno);
+       printf("rtm_use=%d\n", rtm->rtm_use);
+       printf("rtm_inits=%d\n", rtm->rtm_inits);
+       printf("rtm_rmx.rmx_expire=%lld\n", (long long)rtm->rtm_rmx.rmx_expire);
+}
+#endif
+
 
 /*
  * sifproxyarp - Make a proxy ARP entry for the peer.
  */
-static struct {
-    struct rt_msghdr           hdr;
-    struct sockaddr_inarp      dst;
-    struct sockaddr_dl         hwa;
-    char                       extra[128];
-} arpmsg;
-
-static int arpmsg_valid;
-
 int
 sifproxyarp(int unit, u_int32_t hisaddr)
 {
     int routes;
+    struct sockaddr_inarp dst;
+    struct sockaddr_dl sdl;
+    char *cp;
 
     /*
      * Get the hardware address of an interface on the same subnet
      * as our local address.
      */
     memset(&arpmsg, 0, sizeof(arpmsg));
-    if (!get_ether_addr(hisaddr, &arpmsg.hwa)) {
+    if (!get_ether_addr(hisaddr, &sdl)) {
        error("%s: Cannot determine ethernet address for proxy ARP", __func__);
        return 0;
     }
 
-    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
        error("%s: Couldn't add proxy arp entry: socket: %m", __func__);
        return 0;
     }
@@ -1642,19 +1676,29 @@
     arpmsg.hdr.rtm_seq = ++rtm_seq;
     arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
     arpmsg.hdr.rtm_inits = RTV_EXPIRE;
-    arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp);
-    arpmsg.dst.sin_family = AF_INET;
-    arpmsg.dst.sin_addr.s_addr = hisaddr;
-    arpmsg.dst.sin_other = SIN_PROXY;
+
+    memset(&dst, 0, sizeof(dst));
+    dst.sin_len = sizeof(struct sockaddr_in);
+    dst.sin_family = AF_INET;
+    dst.sin_addr.s_addr = hisaddr;
+    dst.sin_other = SIN_PROXY;
 
-    arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
-       + RT_ROUNDUP(arpmsg.hwa.sdl_len);
+    cp = arpmsg.space;
+#define NEXTADDR(s) \
+    (void)memcpy(cp, &s, (size_t)((struct sockaddr *)(void *)&s)->sa_len), \
+    RT_ADVANCE(cp, ((struct sockaddr *)(void *)&s))
+    NEXTADDR(dst);
+    NEXTADDR(sdl);
+    arpmsg.hdr.rtm_msglen = cp - (char *)(void *)&arpmsg;
+
     if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
        error("%s: Couldn't add proxy arp entry: %m", __func__);
        close(routes);
        return 0;
     }
 
+    consume(routes);
+
     close(routes);
     arpmsg_valid = 1;
     proxy_arp_addr = hisaddr;
@@ -1676,7 +1720,7 @@
     arpmsg.hdr.rtm_type = RTM_DELETE;
     arpmsg.hdr.rtm_seq = ++rtm_seq;
 
-    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
        if (!doing_cleanup)
            error("%s: Couldn't delete proxy arp entry: socket: %m", __func__);
        return 0;
@@ -1688,6 +1732,8 @@
        close(routes);
        return 0;
     }
+    consume(routes);
+
 
     close(routes);
     proxy_arp_addr = 0;
@@ -1754,6 +1800,16 @@
 }
 #endif /* RTM_VERSION */
 
+static struct ifaddrs *
+getlink(struct ifaddrs *ifa, const char *name)
+{
+    for (; ifa; ifa = ifa->ifa_next)
+       if (strcmp(ifa->ifa_name, name) == 0 &&
+           ifa->ifa_addr->sa_family == AF_LINK)
+           return ifa;
+    return NULL;
+}
+
 
 /*
  * get_ether_addr - get the hardware address of an interface on the
@@ -1762,9 +1818,8 @@
 static int
 get_ether_addr(u_int32_t ipaddr, struct sockaddr_dl *hwaddr)
 {
-    u_int32_t ina, mask;
     struct sockaddr_dl *dla;
-    struct ifaddrs *ifap, *ifa, *ifp;
+    struct ifaddrs *ifap, *ifa, *ifp, *iflink;
 
     /*
      * Scan through looking for an interface with an Internet
@@ -1775,55 +1830,68 @@
        return 0;
     }
 
-    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
-       if (ifa->ifa_addr->sa_family != AF_INET)
-           continue;
-       ina = ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr.s_addr;
+    for (ifp = NULL, ifa = ifap; ifa; ifa = ifa->ifa_next) {
        /*
         * Check that the interface is up, and not point-to-point
         * or loopback.
         */
        if ((ifa->ifa_flags &
             (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|IFF_LOOPBACK|IFF_NOARP))
-            != (IFF_UP|IFF_BROADCAST))
+            != (IFF_UP|IFF_BROADCAST)) {
+           continue;
+       }
+
+       switch (ifa->ifa_addr->sa_family) {
+       case AF_INET:
+       case AF_INET6:
+           /*
+            * See if it has a link address and remember it.
+            */
+           if ((iflink = getlink(ifap, ifa->ifa_name)) == NULL)
+               continue;
+           if (ifp == NULL)
+               ifp = iflink;
+           else
+               info("more than one interfaces match for proxy arp");
+           break;
+       default:
            continue;
-       /*
-        * Get its netmask and check that it's on the right subnet.
-        */
-       mask = ((struct sockaddr_in *) ifa->ifa_netmask)->sin_addr.s_addr;
-       if ((ipaddr & mask) != (ina & mask))
-           continue;
+       }
+
+       switch (ifa->ifa_addr->sa_family) {
+           u_int32_t ina, mask;
+       case AF_INET:
+           /*
+            * Get its netmask and check that it's on the right subnet.
+            */
+           ina = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
+           mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
+           if ((ipaddr & mask) != (ina & mask))
+               continue;
+           ifp = iflink;
+           break;
+       case AF_INET6:
+           /* XXX */
+           break;
+       default:
+           abort();
+       }
        break;
     }
 
-    if (!ifa) {
+    if (!ifp) {
        freeifaddrs(ifap);
        return 0;
     }
-    info("found interface %s for proxy arp", ifa->ifa_name);
-
-    ifp = ifa;
+    info("found interface %s for proxy arp", ifp->ifa_name);
 
     /*
-     * Now scan through again looking for a link-level address
-     * for this interface.
+     * copy out the link-level address
      */
-    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
-       if (strcmp(ifp->ifa_name, ifa->ifa_name) != 0)
-           continue;
-       if (ifa->ifa_addr->sa_family != AF_LINK)
-           continue;
-       /*
-        * Found the link-level address - copy it out
-        */
-       dla = (struct sockaddr_dl *) ifa->ifa_addr;
-       BCOPY(dla, hwaddr, dla->sdl_len);
-       freeifaddrs(ifap);
-       return 1;
-    }
-
+    dla = (struct sockaddr_dl *) ifp->ifa_addr;
+    BCOPY(dla, hwaddr, sizeof(*dla));