babeld: Add MBZ and Reserved field checking

Signed-off-by: zmw12306 <[email protected]>
FRRouting · Sep 3, 2024 · 9731902 · 9731902
1 parent 9b96394
commit 9731902
Showing 1 changed file with 59 additions and 5 deletions.
diff --git a/babeld/message.c b/babeld/message.c
@@ -144,7 +144,12 @@ static bool parse_update_subtlv(const unsigned char *a, int alen,
 		       "Received Mandatory bit set but this FRR version is not prepared to handle it at this point");
 		return true;
 	} else if (type == SUBTLV_PADN) {
-		/* Nothing. */
+        for (int j = 0; j < len; j++) {
+            if (a[i + j + 2] != 0) {
+                debugf(BABEL_DEBUG_COMMON,"Received pad%d with non zero MBZ field.",
+                len);
+            }
+        }
 	} else if (type == SUBTLV_DIVERSITY) {
 		if (len > DIVERSITY_HOPS) {
 			flog_err(
@@ -208,7 +213,12 @@ parse_hello_subtlv(const unsigned char *a, int alen,
 		       "Received subtlv with Mandatory bit, this version of FRR is not prepared to handle this currently");
 		return -2;
 	} else if (type == SUBTLV_PADN) {
-		/* Nothing to do. */
+		for (int j = 0; j < len; j++) {
+            if (a[i + j + 2] != 0) {
+                debugf(BABEL_DEBUG_COMMON,"Received pad%d with non zero MBZ field.",
+                len);
+            }
+        }
 	} else if (type == SUBTLV_TIMESTAMP) {
 		if (len >= 4) {
 			DO_NTOHL(*hello_send_us, a + i + 2);
@@ -255,7 +265,12 @@ parse_ihu_subtlv(const unsigned char *a, int alen,
         }
 
         if(type == SUBTLV_PADN) {
-            /* Nothing to do. */
+            for (int j = 0; j < len; j++) {
+                if (a[i + j + 2] != 0) {
+                    debugf(BABEL_DEBUG_COMMON,"Received pad%d with non zero MBZ field.",
+                    len);
+                }
+            }
         } else if(type == SUBTLV_TIMESTAMP) {
             if(len >= 8) {
                 DO_NTOHL(*hello_send_us, a + i + 2);
@@ -392,12 +407,24 @@ parse_packet(const unsigned char *from, struct interface *ifp,
         len = message[1];
 
         if(type == MESSAGE_PADN) {
+            for (int i = 0; i < len; i++) {
+                if (message[i + 2] != 0) {
+                    debugf(BABEL_DEBUG_COMMON,"Received pad%d with non zero MBZ field from %s on %s.",
+                   len, format_address(from), ifp->name);
+                }
+            }
             debugf(BABEL_DEBUG_COMMON,"Received pad%d from %s on %s.",
                    len, format_address(from), ifp->name);
         } else if(type == MESSAGE_ACK_REQ) {
-            unsigned short nonce, interval;
+            unsigned short nonce, interval, Reserved;
+            DO_NTOHS(Reserved, message + 2);
             DO_NTOHS(nonce, message + 4);
             DO_NTOHS(interval, message + 6);
+            if (Reserved != 0) {
+               debugf(BABEL_DEBUG_COMMON,"Received ack-req (%04X %d) with non zero Reserved from %s on %s.",
+                   nonce, interval, format_address(from), ifp->name);
+               goto done;
+            }
             debugf(BABEL_DEBUG_COMMON,"Received ack-req (%04X %d) from %s on %s.",
                    nonce, interval, format_address(from), ifp->name);
             send_ack(neigh, nonce, interval);
@@ -459,8 +486,15 @@ parse_packet(const unsigned char *from, struct interface *ifp,
 		}
         } else if(type == MESSAGE_IHU) {
             unsigned short txcost, interval;
+            unsigned char Reserved;
             unsigned char address[16];
             int rc;
+            Reserved = message[3];
+            if (Reserved != 0) {
+               debugf(BABEL_DEBUG_COMMON,"Received ihu with non zero Reserved from %s on %s.",
+                   format_address(from), ifp->name);
+               goto done;
+            }
             DO_NTOHS(txcost, message + 4);
             DO_NTOHS(interval, message + 6);
             rc = network_address(message[2], message + 8, len - 6, address);
@@ -484,12 +518,26 @@ parse_packet(const unsigned char *from, struct interface *ifp,
                                      &hello_send_us, &hello_rtt_receive_time);
             }
         } else if(type == MESSAGE_ROUTER_ID) {
+            unsigned short Reserved;
+            DO_NTOHS(Reserved, message + 2);
+            if (Reserved != 0) {
+               debugf(BABEL_DEBUG_COMMON,"Received router-id with non zero Reserved from %s on %s.",
+                   format_address(from), ifp->name);
+               goto done;
+            }
             memcpy(router_id, message + 4, 8);
             have_router_id = 1;
             debugf(BABEL_DEBUG_COMMON,"Received router-id %s from %s on %s.",
                    format_eui64(router_id), format_address(from), ifp->name);
         } else if(type == MESSAGE_NH) {
             unsigned char nh[16];
+            unsigned char Reserved;
+            Reserved = message[3];
+            if (Reserved != 0) {
+               debugf(BABEL_DEBUG_COMMON,"Received nh with non zero Reserved from %s on %s.",
+                   format_address(from), ifp->name);
+               goto done;
+            }
             int rc;
             rc = network_address(message[2], message + 4, len - 2,
                                  nh);
@@ -638,8 +686,14 @@ parse_packet(const unsigned char *from, struct interface *ifp,
                 send_update(neigh->ifp, 0, prefix, plen);
             }
         } else if(type == MESSAGE_MH_REQUEST) {
-            unsigned char prefix[16], plen;
+            unsigned char prefix[16], plen, Reserved;
             unsigned short seqno;
+            Reserved = message[7];
+            if (Reserved != 0) {
+               debugf(BABEL_DEBUG_COMMON,"Received request with non zero Reserved from %s on %s.",
+                   format_address(from), ifp->name);
+               goto done;
+            }
             int rc;
             DO_NTOHS(seqno, message + 4);
             rc = network_prefix(message[2], message[3], 0,