X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/6e3fd952d7052293905334a3bb3911c775222ea6..091433c62a7e2fdb12f60d2468c5f98b9603f429:/netlink.c

diff --git a/netlink.c b/netlink.c
index 2c3d12d..954dbb6 100644
--- a/netlink.c
+++ b/netlink.c
@@ -237,6 +237,11 @@ struct icmphdr {
 
 static const union icmpinfofield icmp_noinfo;
     
+static const char *sender_name(struct netlink_client *sender /* or NULL */)
+{
+    return sender?sender->name:"(local)";
+}
+
 static void netlink_packet_deliver(struct netlink *st,
 				   struct netlink_client *client,
 				   struct buffer_if *buf);
@@ -376,7 +381,9 @@ static uint16_t netlink_icmp_reply_len(struct buffer_if *buf)
 
 /* client indicates where the packet we're constructing a response to
    comes from. NULL indicates the host. */
-static void netlink_icmp_simple(struct netlink *st, struct buffer_if *buf,
+static void netlink_icmp_simple(struct netlink *st,
+				struct netlink_client *origsender,
+				struct buffer_if *buf,
 				uint8_t type, uint8_t code,
 				union icmpinfofield info)
 {
@@ -465,6 +472,7 @@ static const char *fragment_filter_header(uint8_t *base, long *hlp)
 
 /* Fragment or send ICMP Fragmentation Needed */
 static void netlink_maybe_fragment(struct netlink *st,
+				   struct netlink_client *sender,
 				   netlink_deliver_fn *deliver,
 				   void *deliver_dst,
 				   const char *delivery_name,
@@ -496,7 +504,7 @@ static void netlink_maybe_fragment(struct netlink *st,
     if (orig_frag&IPHDR_FRAG_DONT) {
 	union icmpinfofield info =
 	    { .fragneeded = { .unused = 0, .mtu = htons(mtu) } };
-	netlink_icmp_simple(st,buf,
+	netlink_icmp_simple(st,sender,buf,
 			    ICMP_TYPE_UNREACHABLE,
 			    ICMP_CODE_FRAGMENTATION_REQUIRED,
 			    info);
@@ -591,7 +599,7 @@ static void netlink_client_deliver(struct netlink *st,
 	BUF_FREE(buf);
 	return;
     }
-    netlink_maybe_fragment(st, client->deliver,client->dst,client->name,
+    netlink_maybe_fragment(st,NULL, client->deliver,client->dst,client->name,
 			   client->mtu, source,dest,buf);
     client->outcount++;
 }
@@ -599,24 +607,24 @@ static void netlink_client_deliver(struct netlink *st,
 /* Deliver a packet to the host; used after we have decided that that
  * is what to do with it. */
 static void netlink_host_deliver(struct netlink *st,
+				 struct netlink_client *sender,
 				 uint32_t source, uint32_t dest,
 				 struct buffer_if *buf)
 {
-    netlink_maybe_fragment(st, st->deliver_to_host,st->dst,"(host)",
+    netlink_maybe_fragment(st,sender, st->deliver_to_host,st->dst,"(host)",
 			   st->mtu, source,dest,buf);
     st->outcount++;
 }
 
-/* Deliver a packet. "client" is the _origin_ of the packet, not its
-   destination, and is NULL for packets from the host and packets
+/* Deliver a packet. "sender"==NULL for packets from the host and packets
    generated internally in secnet.  */
 static void netlink_packet_deliver(struct netlink *st,
-				   struct netlink_client *client,
+				   struct netlink_client *sender,
 				   struct buffer_if *buf)
 {
     if (buf->size < (int)sizeof(struct iphdr)) {
 	Message(M_ERR,"%s: trying to deliver a too-short packet"
-		" from %s!\n",st->name, client?client->name:"(local)");
+		" from %s!\n",st->name, sender_name(sender));
 	BUF_FREE(buf);
 	return;
     }
@@ -638,9 +646,9 @@ static void netlink_packet_deliver(struct netlink *st,
 	return;
     }
     
-    /* Packets from the host (client==NULL) may always be routed.  Packets
+    /* Packets from the host (sender==NULL) may always be routed.  Packets
        from clients with the allow_route option will also be routed. */
-    if (!client || (client && (client->options & OPT_ALLOWROUTE)))
+    if (!sender || (sender && (sender->options & OPT_ALLOWROUTE)))
 	allow_route=True;
 
     /* If !allow_route, we check the routing table anyway, and if
@@ -686,7 +694,7 @@ static void netlink_packet_deliver(struct netlink *st,
 	/* The packet's not going down a tunnel.  It might (ought to)
 	   be for the host.   */
 	if (ipset_contains_addr(st->networks,dest)) {
-	    netlink_host_deliver(st,source,dest,buf);
+	    netlink_host_deliver(st,sender,source,dest,buf);
 	    BUF_ASSERT_FREE(buf);
 	} else {
 	    string_t s,d;
@@ -695,7 +703,7 @@ static void netlink_packet_deliver(struct netlink *st,
 	    Message(M_DEBUG,"%s: don't know where to deliver packet "
 		    "(s=%s, d=%s)\n", st->name, s, d);
 	    free(s); free(d);
-	    netlink_icmp_simple(st,buf,ICMP_TYPE_UNREACHABLE,
+	    netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE,
 				ICMP_CODE_NET_UNREACHABLE, icmp_noinfo);
 	    BUF_FREE(buf);
 	}
@@ -712,7 +720,7 @@ static void netlink_packet_deliver(struct netlink *st,
 		    st->name,s,d);
 	    free(s); free(d);
 		    
-	    netlink_icmp_simple(st,buf,ICMP_TYPE_UNREACHABLE,
+	    netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE,
 				ICMP_CODE_NET_PROHIBITED, icmp_noinfo);
 	    BUF_FREE(buf);
 	} else {
@@ -722,7 +730,7 @@ static void netlink_packet_deliver(struct netlink *st,
 		BUF_ASSERT_FREE(buf);
 	    } else {
 		/* Generate ICMP destination unreachable */
-		netlink_icmp_simple(st,buf,
+		netlink_icmp_simple(st,sender,buf,
 				    ICMP_TYPE_UNREACHABLE,
 				    ICMP_CODE_NET_UNREACHABLE,
 				    icmp_noinfo);
@@ -734,7 +742,7 @@ static void netlink_packet_deliver(struct netlink *st,
 }
 
 static void netlink_packet_forward(struct netlink *st, 
-				   struct netlink_client *client,
+				   struct netlink_client *sender,
 				   struct buffer_if *buf)
 {
     if (buf->size < (int)sizeof(struct iphdr)) return;
@@ -745,7 +753,7 @@ static void netlink_packet_forward(struct netlink *st,
     /* Packet has already been checked */
     if (iph->ttl<=1) {
 	/* Generate ICMP time exceeded */
-	netlink_icmp_simple(st,buf,ICMP_TYPE_TIME_EXCEEDED,
+	netlink_icmp_simple(st,sender,buf,ICMP_TYPE_TIME_EXCEEDED,
 			    ICMP_CODE_TTL_EXCEEDED,icmp_noinfo);
 	BUF_FREE(buf);
 	return;
@@ -754,13 +762,13 @@ static void netlink_packet_forward(struct netlink *st,
     iph->check=0;
     iph->check=ip_fast_csum((uint8_t *)iph,iph->ihl);
 
-    netlink_packet_deliver(st,client,buf);
+    netlink_packet_deliver(st,sender,buf);
     BUF_ASSERT_FREE(buf);
 }
 
 /* Deal with packets addressed explicitly to us */
 static void netlink_packet_local(struct netlink *st,
-				 struct netlink_client *client,
+				 struct netlink_client *sender,
 				 struct buffer_if *buf)
 {
     struct icmphdr *h;
@@ -803,7 +811,7 @@ static void netlink_packet_local(struct netlink *st,
 	Message(M_WARNING,"%s: unknown incoming ICMP\n",st->name);
     } else {
 	/* Send ICMP protocol unreachable */
-	netlink_icmp_simple(st,buf,ICMP_TYPE_UNREACHABLE,
+	netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE,
 			    ICMP_CODE_PROTOCOL_UNREACHABLE,icmp_noinfo);
 	BUF_FREE(buf);
 	return;
@@ -814,13 +822,13 @@ static void netlink_packet_local(struct netlink *st,
 
 /* If cid==NULL packet is from host, otherwise cid specifies which tunnel 
    it came from. */
-static void netlink_incoming(struct netlink *st, struct netlink_client *client,
+static void netlink_incoming(struct netlink *st, struct netlink_client *sender,
 			     struct buffer_if *buf)
 {
     uint32_t source,dest;
     struct iphdr *iph;
     char errmsgbuf[50];
-    const char *sourcedesc=client?client->name:"host";
+    const char *sourcedesc=sender?sender->name:"host";
 
     BUF_ASSERT_USED(buf);
 
@@ -831,7 +839,7 @@ static void netlink_incoming(struct netlink *st, struct netlink_client *client,
 	BUF_FREE(buf);
 	return;
     }
-    assert(buf->size >= (int)sizeof(struct icmphdr));
+    assert(buf->size >= (int)sizeof(struct iphdr));
     iph=(struct iphdr *)buf->start;
 
     source=ntohl(iph->saddr);
@@ -840,15 +848,15 @@ static void netlink_incoming(struct netlink *st, struct netlink_client *client,
     /* Check source. If we don't like the source, there's no point
        generating ICMP because we won't know how to get it to the
        source of the packet. */
-    if (client) {
+    if (sender) {
 	/* Check that the packet source is appropriate for the tunnel
 	   it came down */
-	if (!ipset_contains_addr(client->networks,source)) {
+	if (!ipset_contains_addr(sender->networks,source)) {
 	    string_t s,d;
 	    s=ipaddr_to_string(source);
 	    d=ipaddr_to_string(dest);
 	    Message(M_WARNING,"%s: packet from tunnel %s with bad "
-		    "source address (s=%s,d=%s)\n",st->name,client->name,s,d);
+		    "source address (s=%s,d=%s)\n",st->name,sender->name,s,d);
 	    free(s); free(d);
 	    BUF_FREE(buf);
 	    return;
@@ -875,8 +883,8 @@ static void netlink_incoming(struct netlink *st, struct netlink_client *client,
        where it came from.  It's up to external software to check
        address validity and generate ICMP, etc. */
     if (st->ptp) {
-	if (client) {
-	    netlink_host_deliver(st,source,dest,buf);
+	if (sender) {
+	    netlink_host_deliver(st,sender,source,dest,buf);
 	} else {
 	    netlink_client_deliver(st,st->clients,source,dest,buf);
 	}
@@ -887,11 +895,11 @@ static void netlink_incoming(struct netlink *st, struct netlink_client *client,
     /* st->secnet_address needs checking before matching destination
        addresses */
     if (dest==st->secnet_address) {
-	netlink_packet_local(st,client,buf);
+	netlink_packet_local(st,sender,buf);
 	BUF_ASSERT_FREE(buf);
 	return;
     }
-    netlink_packet_forward(st,client,buf);
+    netlink_packet_forward(st,sender,buf);
     BUF_ASSERT_FREE(buf);
 }
 
@@ -1028,12 +1036,16 @@ static void netlink_inst_set_mtu(void *sst, int32_t new_mtu)
 }
 
 static void netlink_inst_reg(void *sst, netlink_deliver_fn *deliver, 
-			     void *dst)
+			     void *dst, uint32_t *localmtu_r)
 {
     struct netlink_client *c=sst;
+    struct netlink *st=c->nst;
 
     c->deliver=deliver;
     c->dst=dst;
+
+    if (localmtu_r)
+	*localmtu_r=st->mtu;
 }
 
 static struct flagstr netlink_option_table[]={
@@ -1186,6 +1198,8 @@ netlink_deliver_fn *netlink_init(struct netlink *st,
 	st->remote_networks=ipset_complement(empty);
 	ipset_free(empty);
     }
+    st->local_address=string_item_to_ipaddr(
+	dict_find_item(dict,"local-address", True, "netlink", loc),"netlink");
 
     sa=dict_find_item(dict,"secnet-address",False,"netlink",loc);
     ptpa=dict_find_item(dict,"ptp-address",False,"netlink",loc);