Implement dynamic interface discovery on *BSD

CHANGELOG

@@ -1,3 +1,10 @@
+version 2.69
+	    Implement dynamic interface discovery on *BSD. This allows
+	    the contructor: syntax to be used in dhcp-range for DHCPv6
+	    on the BSD platform. Thanks to Matthias Andree for
+	    valuable research on how to implement this.
+
+
 version 2.68
             Use random addresses for DHCPv6 temporary address
             allocations, instead of algorithmically determined stable

src/bpf.c

@@ -19,9 +19,9 @@
 #if defined(HAVE_BSD_NETWORK) || defined(HAVE_SOLARIS_NETWORK)
 #include <ifaddrs.h>
 
-#if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
 #include <sys/param.h>
 #include <sys/sysctl.h>
+#include <net/if.h>
 #include <net/route.h>
 #include <net/if_dl.h>
 #include <netinet/if_ether.h>
@@ -29,7 +29,9 @@
 #  include <net/if_var.h> 
 #endif
 #include <netinet/in_var.h>
-#include <netinet6/in6_var.h>
+#ifdef HAVE_IPV6
+#  include <netinet6/in6_var.h>
+#endif
 
 #ifndef SA_SIZE
 #define SA_SIZE(sa)                                             \
@@ -38,6 +40,13 @@
         1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
 #endif
 
+#ifdef HAVE_BSD_NETWORK
+static int del_family = 0;
+static struct all_addr del_addr;
+#endif
+
+#if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
+
 int arp_enumerate(void *parm, int (*callback)())
 {
   int mib[6];
@@ -88,7 +97,7 @@ int arp_enumerate(void *parm, int (*callback)())
 
   return 1;
 }
-#endif
+#endif /* defined(HAVE_BSD_NETWORK) && !defined(__APPLE__) */
 
 
 int iface_enumerate(int family, void *parm, int (*callback)())
@@ -129,6 +138,10 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	    {
 	      struct in_addr addr, netmask, broadcast;
 	      addr = ((struct sockaddr_in *) addrs->ifa_addr)->sin_addr;
+#ifdef HAVE_BSD_NETWORK
+	      if (del_family == AF_INET && del_addr.addr.addr4.s_addr == addr.s_addr)
+		continue;
+#endif
 	      netmask = ((struct sockaddr_in *) addrs->ifa_netmask)->sin_addr;
 	      if (addrs->ifa_broadaddr)
 		broadcast = ((struct sockaddr_in *) addrs->ifa_broadaddr)->sin_addr; 
@@ -146,6 +159,10 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	      int i, j, prefix = 0;
 	      u32 valid = 0xffffffff, preferred = 0xffffffff;
 	      int flags = 0;
+#ifdef HAVE_BSD_NETWORK
+	      if (del_family == AF_INET6 && IN6_ARE_ADDR_EQUAL(&del_addr.addr.addr6, addr))
+		continue;
+#endif
 #if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
 	      struct in6_ifreq ifr6;
 
@@ -226,7 +243,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 
   return ret;
 }
-#endif
+#endif /* defined(HAVE_BSD_NETWORK) || defined(HAVE_SOLARIS_NETWORK) */
 
 
 #if defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP)
@@ -345,6 +362,87 @@ void send_via_bpf(struct dhcp_packet *mess, size_t len,
   while (writev(daemon->dhcp_raw_fd, iov, 4) == -1 && retry_send());
 }
 
+#endif /* defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP) */
+ 
+
+#ifdef HAVE_BSD_NETWORK
+
+void route_init(void)
+{
+  /* AF_UNSPEC: all addr families */
+  daemon->routefd = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
+  
+  if (daemon->routefd == -1 || !fix_fd(daemon->routefd))
+    die(_("cannot create PF_ROUTE socket: %s"), NULL, EC_BADNET);
+}
+
+void route_sock(time_t now)
+{
+  struct if_msghdr *msg;
+  int rc = recv(daemon->routefd, daemon->packet, daemon->packet_buff_sz, 0);
+
+  if (rc < 4)
+    return;
+
+  msg = (struct if_msghdr *)daemon->packet;
+  
+  if (rc < msg->ifm_msglen)
+    return;
+
+   if (msg->ifm_version != RTM_VERSION)
+     {
+       static int warned = 0;
+       if (!warned)
+	 {
+	   my_syslog(LOG_WARNING, _("Unknown protocol version from route socket"));
+	   warned = 1;
+	 }
+     }
+   else if (msg->ifm_type == RTM_NEWADDR)
+     {
+       del_family = 0;
+       newaddress(now);
+     }
+   else if (msg->ifm_type == RTM_DELADDR)
+     {
+       /* There's a race in the kernel, such that if we run iface_enumerate() immediately
+	  we get a DELADDR event, the deleted address still appears. Here we store the deleted address
+	  in a static variable, and omit it from the set returned by iface_enumerate() */
+       int mask = ((struct ifa_msghdr *)msg)->ifam_addrs;
+       int maskvec[] = { RTA_DST, RTA_GATEWAY, RTA_NETMASK, RTA_GENMASK,
+			 RTA_IFP, RTA_IFA, RTA_AUTHOR, RTA_BRD };
+       int of;
+       unsigned int i;
+       
+       for (i = 0,  of = sizeof(struct ifa_msghdr); of < rc && i < sizeof(maskvec)/sizeof(maskvec[0]); i++) 
+	 if (mask & maskvec[i]) 
+	   {
+	     struct sockaddr *sa = (struct sockaddr *)((char *)msg + of);
+	     size_t diff = (sa->sa_len != 0) ? sa->sa_len : sizeof(long);
+	     
+	     if (maskvec[i] == RTA_IFA)
+	       {
+		 del_family = sa->sa_family;
+		 if (del_family == AF_INET)
+		   del_addr.addr.addr4 = ((struct sockaddr_in *)sa)->sin_addr;
+#ifdef HAVE_IPV6
+		 else if (del_family == AF_INET6)
+		   del_addr.addr.addr6 = ((struct sockaddr_in6 *)sa)->sin6_addr;
 #endif
+		 else
+		   del_family = 0;
+	       }
+	     
+	     of += diff;
+	     /* round up as needed */
+	     if (diff & (sizeof(long) - 1)) 
+	       of += sizeof(long) - (diff & (sizeof(long) - 1));
+	   }
+       
+       newaddress(now);
+     }
+}
+
+#endif /* HAVE_BSD_NETWORK */
 
 

src/dhcp6.c

@@ -720,7 +720,6 @@ void dhcp_construct_contexts(time_t now)
      
       if (context->flags & CONTEXT_GC && !(context->flags & CONTEXT_OLD))
 	{
-	  
 	  if ((context->flags & (CONTEXT_RA_ONLY | CONTEXT_RA_NAME | CONTEXT_RA_STATELESS)) ||
 	      option_bool(OPT_RA))
 	    {

src/dnsmasq.c

@@ -182,7 +182,7 @@ int main (int argc, char **argv)
 	    daemon->doing_dhcp6 = 1;
 	  if (context->flags & CONTEXT_RA)
 	    daemon->doing_ra = 1;
-#ifndef  HAVE_LINUX_NETWORK
+#if !defined(HAVE_LINUX_NETWORK) && !defined(HAVE_BSD_NETWORK)
 	  if (context->flags & CONTEXT_TEMPLATE)
 	    die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF);
 #endif 
@@ -220,13 +220,15 @@ int main (int argc, char **argv)
     ipset_init();
 #endif
 
-#ifdef HAVE_LINUX_NETWORK
+#if  defined(HAVE_LINUX_NETWORK)
   netlink_init();
-  
+#elif defined(HAVE_BSD_NETWORK)
-  if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND))
+  route_init();
-    die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF);
 #endif
 
+  if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND))
+    die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF);
+  
   if (!enumerate_interfaces(1) || !enumerate_interfaces(0))
     die(_("failed to find list of interfaces: %s"), NULL, EC_MISC);
   
@@ -808,11 +810,14 @@ int main (int argc, char **argv)
 	}
 #endif
 
-#ifdef HAVE_LINUX_NETWORK
+#if defined(HAVE_LINUX_NETWORK)
       FD_SET(daemon->netlinkfd, &rset);
       bump_maxfd(daemon->netlinkfd, &maxfd);
+#elif defined(HAVE_BSD_NETWORK)
+      FD_SET(daemon->routefd, &rset);
+      bump_maxfd(daemon->routefd, &maxfd);
 #endif
-      
+
       FD_SET(piperead, &rset);
       bump_maxfd(piperead, &maxfd);
 
@@ -867,9 +872,12 @@ int main (int argc, char **argv)
 	  warn_bound_listeners();
 	}
 
-#ifdef HAVE_LINUX_NETWORK
+#if defined(HAVE_LINUX_NETWORK)
       if (FD_ISSET(daemon->netlinkfd, &rset))
 	netlink_multicast(now);
+#elif defined(HAVE_BSD_NETWORK)
+      if (FD_ISSET(daemon->routefd, &rset))
+	route_sock(now);
 #endif
 
       /* Check for changes to resolv files once per second max. */

src/dnsmasq.h

@@ -900,7 +900,7 @@ extern struct daemon {
 #if defined(HAVE_LINUX_NETWORK)
   int netlinkfd;
 #elif defined(HAVE_BSD_NETWORK)
-  int dhcp_raw_fd, dhcp_icmp_fd;
+  int dhcp_raw_fd, dhcp_icmp_fd, routefd;
 #endif
   struct iovec dhcp_packet;
   char *dhcp_buff, *dhcp_buff2, *dhcp_buff3;
@@ -1090,6 +1090,10 @@ int set_ipv6pktinfo(int fd);
 #ifdef HAVE_DHCP6
 void join_multicast(int dienow);
 #endif
+#if defined(HAVE_LINUX_NETWORK) || defined(HAVE_BSD_NETWORK)
+void newaddress(time_t now);
+#endif
+
 
 /* dhcp.c */
 #ifdef HAVE_DHCP
@@ -1177,6 +1181,8 @@ void netlink_multicast(time_t now);
 void init_bpf(void);
 void send_via_bpf(struct dhcp_packet *mess, size_t len,
 		  struct in_addr iface_addr, struct ifreq *ifr);
+void route_init(void);
+void route_sock(time_t now);
 #endif
 
 /* bpf.c or netlink.c */

src/netlink.c

@@ -39,7 +39,6 @@ static struct iovec iov;
 static u32 netlink_pid;
 
 static int nl_async(struct nlmsghdr *h);
-static void nl_newaddress(time_t now);
 
 void netlink_init(void)
 {
@@ -203,7 +202,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	    /* handle async new interface address arrivals, these have to be done
 	       after we complete as we're not re-entrant */
 	    if (newaddr) 
-	      nl_newaddress(dnsmasq_time());
+	      newaddress(dnsmasq_time());
 		
 	    return callback_ok;
 	  }
@@ -351,7 +350,7 @@ void netlink_multicast(time_t now)
   fcntl(daemon->netlinkfd, F_SETFL, flags);
   
   if (newaddr) 
-    nl_newaddress(now);
+    newaddress(now);
 }
 
 static int nl_async(struct nlmsghdr *h)
@@ -399,30 +398,6 @@ static int nl_async(struct nlmsghdr *h)
   
   return 0;
 }
-  	
-static void nl_newaddress(time_t now)
-{
-  (void)now;
-
-  if (option_bool(OPT_CLEVERBIND) || daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
-    enumerate_interfaces(0);
-  
-  if (option_bool(OPT_CLEVERBIND))
-    create_bound_listeners(0);
-  
-#ifdef HAVE_DHCP6
-  if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
-    join_multicast(0);
-  
-  if (daemon->doing_dhcp6 || daemon->doing_ra)
-    dhcp_construct_contexts(now);
-  
-  if (daemon->doing_dhcp6)
-    lease_find_interfaces(now);
-#endif
-}
-
-
 #endif
 
       

src/network.c

@@ -489,7 +489,7 @@ static int iface_allowed_v6(struct in6_addr *local, int prefix,
     addr.in6.sin6_scope_id = if_index;
   else
     addr.in6.sin6_scope_id = 0;
-
+  
   return iface_allowed((struct iface_param *)vparam, if_index, NULL, &addr, netmask, prefix, !!(flags & IFACE_TENTATIVE));
 }
 #endif
@@ -681,7 +681,7 @@ static int make_sock(union mysockaddr *addr, int type, int dienow)
 	close (fd);
 	
       errno = errsav;
-      
+
       if (dienow)
 	{
 	  /* failure to bind addresses given by --listen-address at this point
@@ -1470,7 +1470,31 @@ int reload_servers(char *fname)
   return gotone;
 }
 
-
+#if defined(HAVE_LINUX_NETWORK) || defined(HAVE_BSD_NETWORK)
+/* Called when addresses are added or deleted from an interface */
+void newaddress(time_t now)
+{
+  (void)now;
+  
+  if (option_bool(OPT_CLEVERBIND) || daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
+    enumerate_interfaces(0);
+  
+  if (option_bool(OPT_CLEVERBIND))
+    create_bound_listeners(0);
+  
+#ifdef HAVE_DHCP6
+  if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
+    join_multicast(0);
+  
+  if (daemon->doing_dhcp6 || daemon->doing_ra)
+    dhcp_construct_contexts(now);
+  
+  if (daemon->doing_dhcp6)
+    lease_find_interfaces(now);
+#endif
+}
+
+#endif