xnu-1504.3.12.tar.gz

[apple/xnu.git] / bsd / netinet / in_arp.c

diff --git a/bsd/netinet/in_arp.c b/bsd/netinet/in_arp.c
index 6897e77ac87492b9b26765821083930e7db20a02..c553930f1b13fde46a8c263eac47dd2b8837f6f4 100644 (file)
--- a/bsd/netinet/in_arp.c
+++ b/bsd/netinet/in_arp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2004-2009 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -74,6 +74,7 @@
 #include <net/if_arp.h>
 #include <net/if_dl.h>
 #include <net/dlil.h>
+#include <net/if_types.h>
 #include <net/route.h>
 #include <netinet/if_ether.h>
 #include <netinet/in_var.h>
@@ -937,34 +938,64 @@ arp_ip_handle_input(
        struct llinfo_arp *llinfo;
        errno_t error;
        int created_announcement = 0;
-
+       int bridged = 0, is_bridge = 0;
+       
        /* Do not respond to requests for 0.0.0.0 */
        if (target_ip->sin_addr.s_addr == 0 && arpop == ARPOP_REQUEST)
                goto done;
+       
+       if (ifp->if_bridge)
+               bridged = 1;
+       if (ifp->if_type == IFT_BRIDGE)
+               is_bridge = 1;
 
        /*
         * Determine if this ARP is for us
+        * For a bridge, we want to check the address irrespective 
+        * of the receive interface.
         */
        lck_rw_lock_shared(in_ifaddr_rwlock);
        TAILQ_FOREACH(ia, INADDR_HASH(target_ip->sin_addr.s_addr), ia_hash) {
-               /* do_bridge should be tested here for bridging */
-               if (ia->ia_ifp == ifp &&
+               if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
+                       (ia->ia_ifp == ifp)) &&
                    ia->ia_addr.sin_addr.s_addr == target_ip->sin_addr.s_addr) {
-                       best_ia = ia;
-                       ifaref(&best_ia->ia_ifa);
-                       lck_rw_done(in_ifaddr_rwlock);
-                       goto match;
+                               best_ia = ia;
+                               ifaref(&best_ia->ia_ifa);
+                               lck_rw_done(in_ifaddr_rwlock);
+                               goto match;
                }
        }
 
        TAILQ_FOREACH(ia, INADDR_HASH(sender_ip->sin_addr.s_addr), ia_hash) {
-               /* do_bridge should be tested here for bridging */
-               if (ia->ia_ifp == ifp &&
+               if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
+                       (ia->ia_ifp == ifp)) &&
                    ia->ia_addr.sin_addr.s_addr == sender_ip->sin_addr.s_addr) {
-                       best_ia = ia;
-                       ifaref(&best_ia->ia_ifa);
-                       lck_rw_done(in_ifaddr_rwlock);
-                       goto match;
+                               best_ia = ia;
+                               ifaref(&best_ia->ia_ifa);
+                               lck_rw_done(in_ifaddr_rwlock);
+                               goto match;
+               }
+       }
+
+#define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia)                                                          \
+       (ia->ia_ifp->if_bridge == ifp->if_softc &&                                                              \
+       !bcmp(ifnet_lladdr(ia->ia_ifp), ifnet_lladdr(ifp), ifp->if_addrlen) &&  \
+       addr == ia->ia_addr.sin_addr.s_addr)
+       /*
+        * Check the case when bridge shares its MAC address with
+        * some of its children, so packets are claimed by bridge
+        * itself (bridge_input() does it first), but they are really
+        * meant to be destined to the bridge member.
+        */
+       if (is_bridge) {
+               TAILQ_FOREACH(ia, INADDR_HASH(target_ip->sin_addr.s_addr), ia_hash) {
+                       if (BDG_MEMBER_MATCHES_ARP(target_ip->sin_addr.s_addr, ifp, ia)) {
+                               ifp = ia->ia_ifp;
+                               best_ia = ia;
+                               ifaref(&best_ia->ia_ifa);
+                               lck_rw_done(in_ifaddr_rwlock);
+                               goto match;
+                       }
                }
        }
        lck_rw_done(in_ifaddr_rwlock);
@@ -980,12 +1011,16 @@ arp_ip_handle_input(
                        continue;
                best_ia = (struct in_ifaddr *)ifa;
                ifaref(&best_ia->ia_ifa);
-               break;
+               ifnet_lock_done(ifp);
+               goto match;
        }
        ifnet_lock_done(ifp);
 
-       /* If we don't have an IP address on this interface, ignore the packet */
-       if (best_ia == NULL)
+       /*
+        * If we're not a bridge member, or if we are but there's no
+        * IPv4 address to use for the interface, drop the packet.
+        */
+       if (!bridged || best_ia == NULL)
                goto done;
 
 match:
@@ -995,7 +1030,7 @@ match:
        }
 
        /* Check for a conflict */
-       if (sender_ip->sin_addr.s_addr == best_ia->ia_addr.sin_addr.s_addr) {
+       if (!bridged && sender_ip->sin_addr.s_addr == best_ia->ia_addr.sin_addr.s_addr) {
                struct kev_msg        ev_msg;
                struct kev_in_collision *in_collision;
                u_char  storage[sizeof(struct kev_in_collision) + MAX_HW_LEN];
@@ -1152,7 +1187,7 @@ match:
 
        RT_LOCK_ASSERT_HELD(route);
        gateway = SDL(route->rt_gateway);
-       if (route->rt_ifp != ifp) {
+       if (!bridged && route->rt_ifp != ifp) {
                if (!IN_LINKLOCAL(ntohl(sender_ip->sin_addr.s_addr)) || (ifp->if_eflags & IFEF_ARPLL) == 0) {
                        if (log_arp_warnings)
                                log(LOG_ERR, "arp: %s is on %s%d but got reply from %s on %s%d\n",
@@ -1286,6 +1321,19 @@ respond:
 
                if (error == 0) {
                        RT_LOCK_ASSERT_HELD(route);
+                       /*
+                        * Return proxied ARP replies only on the interface
+                        * or bridge cluster where this network resides.
+                        * Otherwise we may conflict with the host we are
+                        * proxying for.
+                        */
+                       if (route->rt_ifp != ifp &&
+                               (route->rt_ifp->if_bridge != ifp->if_bridge ||
+                                ifp->if_bridge == NULL)) {
+                                       RT_REMREF_LOCKED(route);
+                                       RT_UNLOCK(route);
+                                       goto done;
+                               }
                        proxied = *SDL(route->rt_gateway);
                        target_hw = &proxied;
                } else {