(for 4.9.3) LDP: Add some missing bounds checks

[tcpdump] / print-ldp.c

diff --git a/print-ldp.c b/print-ldp.c
index 68149bba2447f988dc3ef94f9da2c30465649e2f..e7f00c3524213d35c6b0dd921e7d9b21b75ae1b5 100644 (file)
--- a/print-ldp.c
+++ b/print-ldp.c
@@ -10,7 +10,7 @@
  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
- * Original code by Hannes Gredler (hannes@juniper.net)
+ * Original code by Hannes Gredler (hannes@gredler.at)
  *  and Steinar Haug ([email protected])
  */
 
@@ -29,6 +29,8 @@
 #include "l2vpn.h"
 #include "af.h"
 
+static const char tstr[] = " [|LDP]";
+
 /*
  * ldp common header
  *
@@ -210,7 +212,7 @@ static const struct tok ldp_fec_martini_ifparm_vccv_cv_values[] = {
     { 0, NULL}
 };
 
-static int ldp_pdu_print(netdissect_options *, register const u_char *);
+static u_int ldp_pdu_print(netdissect_options *, register const u_char *);
 
 /*
  * ldp tlv header
@@ -379,17 +381,21 @@ ldp_tlv_print(netdissect_options *ndo,
        case LDP_FEC_HOSTADDRESS:
            break;
        case LDP_FEC_MARTINI_VC:
+            /*
+             * We assume the type was supposed to be one of the MPLS
+             * Pseudowire Types.
+             */
+            TLV_TCHECK(7);
+            vc_info_len = *(tptr+2);
+
             /*
             * According to RFC 4908, the VC info Length field can be zero,
             * in which case not only are there no interface parameters,
             * there's no VC ID.
             */
-            TLV_TCHECK(7);
-            vc_info_len = *(tptr+2);
-
             if (vc_info_len == 0) {
                 ND_PRINT((ndo, ": %s, %scontrol word, group-ID %u, VC-info-length: %u",
-                       tok2str(l2vpn_encaps_values, "Unknown", EXTRACT_16BITS(tptr)&0x7fff),
+                       tok2str(mpls_pw_types_values, "Unknown", EXTRACT_16BITS(tptr)&0x7fff),
                        EXTRACT_16BITS(tptr)&0x8000 ? "" : "no ",
                        EXTRACT_32BITS(tptr+3),
                        vc_info_len));
@@ -399,7 +405,7 @@ ldp_tlv_print(netdissect_options *ndo,
             /* Make sure we have the VC ID as well */
             TLV_TCHECK(11);
            ND_PRINT((ndo, ": %s, %scontrol word, group-ID %u, VC-ID %u, VC-info-length: %u",
-                  tok2str(l2vpn_encaps_values, "Unknown", EXTRACT_16BITS(tptr)&0x7fff),
+                  tok2str(mpls_pw_types_values, "Unknown", EXTRACT_16BITS(tptr)&0x7fff),
                   EXTRACT_16BITS(tptr)&0x8000 ? "" : "no ",
                    EXTRACT_32BITS(tptr+3),
                   EXTRACT_32BITS(tptr+7),
@@ -431,19 +437,24 @@ ldp_tlv_print(netdissect_options *ndo,
 
                 switch(vc_info_tlv_type) {
                 case LDP_FEC_MARTINI_IFPARM_MTU:
+                    ND_TCHECK_16BITS(tptr + 2);
                     ND_PRINT((ndo, ": %u", EXTRACT_16BITS(tptr+2)));
                     break;
 
                 case LDP_FEC_MARTINI_IFPARM_DESC:
                     ND_PRINT((ndo, ": "));
-                    for (idx = 2; idx < vc_info_tlv_len; idx++)
+                    for (idx = 2; idx < vc_info_tlv_len; idx++) {
+                        ND_TCHECK_8BITS(tptr + idx);
                         safeputchar(ndo, *(tptr + idx));
+                    }
                     break;
 
                 case LDP_FEC_MARTINI_IFPARM_VCCV:
+                    ND_TCHECK_8BITS(tptr + 2);
                     ND_PRINT((ndo, "\n\t\t  Control Channels (0x%02x) = [%s]",
                            *(tptr+2),
                            bittok2str(ldp_fec_martini_ifparm_vccv_cc_values, "none", *(tptr+2))));
+                    ND_TCHECK_8BITS(tptr + 3);
                     ND_PRINT((ndo, "\n\t\t  CV Types (0x%02x) = [%s]",
                            *(tptr+3),
                            bittok2str(ldp_fec_martini_ifparm_vccv_cv_values, "none", *(tptr+3))));
@@ -482,7 +493,7 @@ ldp_tlv_print(netdissect_options *ndo,
        break;
 
     case LDP_TLV_FT_SESSION:
-       TLV_TCHECK(8);
+       TLV_TCHECK(12);
        ft_flags = EXTRACT_16BITS(tptr);
        ND_PRINT((ndo, "\n\t      Flags: [%sReconnect, %sSave State, %sAll-Label Protection, %s Checkpoint, %sRe-Learn State]",
               ft_flags&0x8000 ? "" : "No ",
@@ -490,6 +501,7 @@ ldp_tlv_print(netdissect_options *ndo,
               ft_flags&0x4 ? "" : "No ",
               ft_flags&0x2 ? "Sequence Numbered Label" : "All Labels",
               ft_flags&0x1 ? "" : "Don't "));
+       /* 16 bits (FT Flags) + 16 bits (Reserved) */
        tptr+=4;
        ui = EXTRACT_32BITS(tptr);
        if (ui)
@@ -530,7 +542,7 @@ ldp_tlv_print(netdissect_options *ndo,
     return(tlv_len+4); /* Type & Length fields not included */
 
 trunc:
-    ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
+    ND_PRINT((ndo, "%s", tstr));
     return 0;
 
 badtlv:
@@ -542,17 +554,23 @@ void
 ldp_print(netdissect_options *ndo,
           register const u_char *pptr, register u_int len)
 {
-    int processed;
+    u_int processed;
     while (len > (sizeof(struct ldp_common_header) + sizeof(struct ldp_msg_header))) {
         processed = ldp_pdu_print(ndo, pptr);
         if (processed == 0)
             return;
+        if (len < processed) {
+            ND_PRINT((ndo, " [remaining length %u < %u]", len, processed));
+            ND_PRINT((ndo, "%s", istr));
+            break;
+
+        }
         len -= processed;
         pptr += processed;
     }
 }
 
-static int
+static u_int
 ldp_pdu_print(netdissect_options *ndo,
               register const u_char *pptr)
 {
@@ -682,7 +700,7 @@ ldp_pdu_print(netdissect_options *ndo,
     }
     return pdu_len+4;
 trunc:
-    ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
+    ND_PRINT((ndo, "%s", tstr));
     return 0;
 }