Changeset 385678b for lib

Timestamp:

01/14/19 17:36:22 (2 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

develop

Children:

063d5dd

Parents:

2f9b609

Message:

Don't try to guess layer2 payload type when no payload exists.

Fixes #91.

File:

• lib/protocols_l2.c (modified) (4 diffs)

lib/protocols_l2.c

@@ -588 +588 @@
                 return NULL;
         }
-        
+
+        if (link == NULL) {
+                return NULL;
+        }
+
         switch(linktype) {
                 /* Packet Metadata headers, not layer2 headers */
@@ -618 +622 @@
                         return trace_get_payload_from_ethernet(link,ethertype,remaining);
                 case TRACE_TYPE_NONE:
+                        if (*remaining == 0) {
+                                return NULL;
+                        }
+
                         if ((*(char*)link&0xF0) == 0x40)
                                 *ethertype=TRACE_ETHERTYPE_IP;   /* IPv4 */
                         else if ((*(char*)link&0xF0) == 0x60)
                                 *ethertype=TRACE_ETHERTYPE_IPV6; /* IPv6 */
+                        else
+                                return NULL;            /* No idea */
                         return link; /* I love the simplicity */
                 case TRACE_TYPE_PPP:
@@ -646 +656 @@
 
                 case TRACE_TYPE_OPENBSD_LOOP:
+                        if (*remaining <= 4) {
+                                return NULL;
+                        }
                         link = link + 4; /* Loopback header is 4 bytes */
                         if ((*(char*)link&0xF0) == 0x40)
@@ -651 +664 @@
                         else if ((*(char*)link&0xF0) == 0x60)
                                 *ethertype=TRACE_ETHERTYPE_IPV6; /* IPv6 */
+                        else
+                                return NULL;
                         return link; /* I love the simplicity */