Changeset 05f2718

Timestamp:

02/27/13 14:02:17 (9 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:

954577b9

Parents:

0801187

Message:

• Added API functions for getting the ICMPv6 header and the subsequent payload

Location:

lib

Files:

• libtrace.h.in (modified) (2 diffs)
• protocols_transport.c (modified) (2 diffs)

lib/libtrace.h.in

@@ -1918 +1918 @@
                 uint32_t *remaining);
 
+/** Gets a pointer to the payload following a ICMPv6 header
+ * @param icmp           A pointer to the ICMPv6 header
+ * @param[in,out] remaining Updated with the number of captured bytes remaining
+ *
+ * @return A pointer to the ICMPv6 payload, or NULL if the ICMPv6 header is 
+ * truncated.
+ *
+ * When calling this function, remaining must contain the number of captured
+ * bytes remaining in the packet starting from the ICMPv6 header (including the
+ * ICMP header itself). remaining will be updated to contain the number of 
+ * bytes remaining after the ICMPv6 header has been skipped.
+ *
+ * If the ICMPv6 header is complete but there are zero bytes of payload after 
+ * the header, a pointer to where the payload would be is returned and 
+ * remaining will be set to 0.  If the ICMPv6 header is incomplete, NULL will be 
+ * returned and remaining will be set to 0. Therefore, it is important to check
+ * the value of remaining after calling this function.
+ *
+ * @note In the case of some ICMPv6 messages, the payload may be the IP header
+ * from the packet that triggered the ICMP message. 
+ *
+ */
+DLLEXPORT void *trace_get_payload_from_icmp6(libtrace_icmp6_t *icmp, 
+                uint32_t *remaining);
+
 /** Get a pointer to the TCP header (if present)
  * @param packet        The packet to get the TCP header from
@@ -2019 +2044 @@
 DLLEXPORT SIMPLE_FUNCTION
 libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet);
+
+/** Get a pointer to the ICMPv6 header (if present)
+ * @param packet        The packet to get the ICMPv6 header from
+ *
+ * @return A pointer to the ICMPv6 header, or NULL if there is not a complete 
+ * ICMP header present in the packet.
+ *
+ * This is a short-cut function enabling quick and easy access to the ICMPv6
+ * header if that is all you care about. However, we recommend the use of the
+ * more generic trace_get_transport() function instead.
+ *
+ * @note Unlike trace_get_transport(), this function will return NULL if the
+ * ICMPv6 header is incomplete or truncated.
+ */
+DLLEXPORT SIMPLE_FUNCTION
+libtrace_icmp6_t *trace_get_icmp6(libtrace_packet_t *packet);
 
 /** Get a pointer to the ICMP header following an IPv4 header (if present)

lib/protocols_transport.c

@@ -294 +294 @@
 }
 
+DLLEXPORT libtrace_icmp6_t *trace_get_icmp6(libtrace_packet_t *packet) {
+        uint8_t proto;
+        uint32_t rem = 0;
+        libtrace_icmp6_t *icmp;
+
+        icmp=(libtrace_icmp6_t*)trace_get_transport(packet,&proto,&rem);
+
+        if (!icmp || proto != TRACE_IPPROTO_ICMPV6)
+                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_icmp6_t))
+                return NULL;
+
+        return icmp;
+}
+
 DLLEXPORT libtrace_icmp_t *trace_get_icmp_from_ip(libtrace_ip_t *ip, uint32_t *remaining)
 {
@@ -343 +361 @@
 }
 
+DLLEXPORT void *trace_get_payload_from_icmp6(libtrace_icmp6_t *icmp, uint32_t *remaining)
+{
+        if (remaining) {
+                if (*remaining < sizeof(libtrace_icmp6_t)) {
+                        *remaining = 0;
+                        return NULL;
+                }
+                *remaining-=sizeof(libtrace_icmp6_t);
+        }
+        return (char*)icmp+sizeof(libtrace_icmp6_t);
+}
+
 /* Return the source port
  */