Changeset c2afda6

Timestamp:

01/21/10 10:10:46 (11 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, getfragoff, help, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

1481ba7

Parents:

b5a23b3

Message:

• Adjusted the "shortcut" protocol access functions to return NULL if a full header (minus options) is not present.

Location:

lib

Files:

• protocols_l3.c (modified) (2 diffs)
• protocols_transport.c (modified) (3 diffs)

lib/protocols_l3.c

@@ -47 +47 @@
 
         if (!ret || ethertype!=TRACE_ETHERTYPE_IPV6)
+                return NULL;
+
+        /* Make sure we have at least the base IPv6 header */
+        if (remaining < sizeof(libtrace_ip6_t))
                 return NULL;
 
@@ -247 +251 @@
                                            * with these packets
                                            */
+
+                        /* Ensure that optlen is not greater than the
+                         * amount of buffer remaining */
+                        if (*optlen > *len) 
+                                return 0;
+                        
                         (*len)-=*optlen;
                         (*data)=(*ptr+2);

lib/protocols_transport.c

@@ -46 +46 @@
 DLLEXPORT libtrace_tcp_t *trace_get_tcp(libtrace_packet_t *packet) {
         uint8_t proto;
+        uint32_t rem = 0;
         libtrace_tcp_t *tcp;
 
-        tcp=(libtrace_tcp_t*)trace_get_transport(packet,&proto,NULL);
+        tcp=(libtrace_tcp_t*)trace_get_transport(packet,&proto,&rem);
 
         if (!tcp || proto != TRACE_IPPROTO_TCP)
+                return NULL;
+
+        /* We should return NULL if there isn't a full TCP header, because the
+         * caller has no way of telling how much of a TCP header we have
+         * returned - use trace_get_transport() if you want to deal with
+         * partial headers 
+         *
+         * NOTE: We're not going to insist that all the TCP options are present
+         * as well, because lots of traces are snapped after 20 bytes of TCP
+         * header and I don't really want to break libtrace programs that
+         * use this function to process those traces */
+
+        if (rem < sizeof(libtrace_tcp_t))
                 return NULL;
 
@@ -70 +84 @@
 DLLEXPORT libtrace_udp_t *trace_get_udp(libtrace_packet_t *packet) {
         uint8_t proto;
+        uint32_t rem = 0;
         libtrace_udp_t *udp;
 
-        udp=(libtrace_udp_t*)trace_get_transport(packet,&proto,NULL);
+        udp=(libtrace_udp_t*)trace_get_transport(packet,&proto,&rem);
 
         if (!udp || proto != TRACE_IPPROTO_UDP)
+                return NULL;
+
+        /* Make sure we return a full UDP header as the caller has no way of
+         * telling how much of the packet is remaining */
+        if (rem < sizeof(libtrace_udp_t))
                 return NULL;
 
@@ -94 +114 @@
 DLLEXPORT libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet) {
         uint8_t proto;
+        uint32_t rem = 0;
         libtrace_icmp_t *icmp;
 
-        icmp=(libtrace_icmp_t*)trace_get_transport(packet,&proto,NULL);
+        icmp=(libtrace_icmp_t*)trace_get_transport(packet,&proto,&rem);
 
         if (!icmp || proto != TRACE_IPPROTO_ICMP)
+                return NULL;
+
+        /* Make sure we return a full ICMP header as the caller has no way of
+         * telling how much of the packet is remaining */
+        if (rem < sizeof(libtrace_icmp_t))
                 return NULL;