Changeset 68b7f29

Timestamp:

03/06/13 13:31:48 (8 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:

ec0b927

Parents:

c909fad

Message:

• Updated tracereplay to use the new libtrace checksumming functions - tracereplay was kinda broken anyway in that it wouldn't do anything with the TCP/UDP checksums because of a broken call to trace_get_payload_from_ip (bad remaining value).
• As an added benefit, tracereplay show now correctly update the checksums for IPv6 and ICMPv4 packets

File:

• tools/tracereplay/tracereplay.c (modified) (2 diffs)

tools/tracereplay/tracereplay.c

@@ -27 +27 @@
 int broadcast = 0;
 
-/* This function assumes that the relevant fields have been zeroed out. 
-   RFC 1071 describes the method and provides a code example*/
-static uint16_t checksum(void * buffer, uint16_t length) {
-        uint32_t sum = 0;
-        uint16_t * buff = (uint16_t *) buffer;
-        uint16_t count = length;
-
-        while(count > 1 ) {
-                sum += *buff++;
-                count = count -2;
-        }
-
-        if(count > 0) {
-                sum += *buff;
-        }
-
-        while (sum>>16)
-                sum = (sum & 0xffff) + (sum >> 16);
-
-        return ~sum;
-}
-
-/*
-   This function calculates and fills in the correct checksum on
-   a transport protocol header.
-   Currently only UDP and TCP are supported.
- */
-
-static void udp_tcp_checksum(libtrace_ip_t *ip, uint32_t length) {
-
-        uint32_t sum = 0;
-        uint16_t protocol = ip->ip_p;
-        uint16_t temp = 0;
-        uint16_t * check = NULL;
-        uint16_t tsum = 0;
-        void * transportheader = NULL;
-        uint32_t rem;
-
-        sum += (uint16_t) ~checksum(&ip->ip_src.s_addr,sizeof(uint32_t));
-        sum += (uint16_t) ~checksum(&ip->ip_dst.s_addr,sizeof(uint32_t));
-
-
-        /*this will be in host order whereas everything else is in network order*/
-        temp = htons(protocol);
-        sum += (uint16_t) ~checksum(&temp,sizeof(uint16_t));
-
-        /*this will be in host order whereas everything else is in network order*/
-        temp = htons(length);
-        sum += (uint16_t) ~checksum(&temp,sizeof(uint16_t));
-
-        transportheader = trace_get_payload_from_ip(ip,NULL,&rem);
-
-        if (transportheader == NULL)
+static void replace_ip_checksum(libtrace_packet_t *packet) {
+
+        uint16_t *ip_csm_ptr = NULL;
+        uint16_t calc_csum;
+
+        ip_csm_ptr = trace_checksum_layer3(packet, &calc_csum);
+
+        if (ip_csm_ptr == NULL)
                 return;
-
-        /* UDP */
-        if(protocol == 17 ) {
-                libtrace_udp_t * udp_header = transportheader;
-
-                if (rem < sizeof(libtrace_udp_t))
-                        return;
-                check = &udp_header -> check;
-                *check = 0;
-                tsum = checksum(transportheader, length);
-        }
-        /* TCP */
-        else if(protocol == 6) {
-                libtrace_tcp_t * tcp_header = transportheader;
-
-                if (rem < sizeof(libtrace_tcp_t))
-                        return;
-                tcp_header -> check = 0;
-                check = &tcp_header -> check;
-                *check = 0;
-                tsum = checksum(transportheader,length);
-        }
-
-        sum += (uint16_t) ~tsum;
-
-        while (sum>>16)
-                sum = (sum & 0xffff) + (sum >> 16);
-
-        if(check != NULL) {
-                *check = (uint16_t)~sum;
-        }
-
-
+        *ip_csm_ptr = htons(calc_csum);
+
+}
+
+static void replace_transport_checksum(libtrace_packet_t *packet) {
+
+        uint16_t *csm_ptr = NULL;
+        uint16_t calc_csum;
+        
+        csm_ptr = trace_checksum_transport(packet, &calc_csum);
+
+        if (csm_ptr == NULL)
+                return;
+        *csm_ptr = htons(calc_csum);
 
 }
@@ -161 +97 @@
         }
 
-
-
-        header = trace_get_ip(new_packet);
-        if(header != NULL) {
-                /* update ip checksum */
-                wire_length -= sizeof(uint32_t)*header->ip_hl;
-                header -> ip_sum = 0;
-                sum = checksum(header,header->ip_hl*sizeof(uint32_t));
-                header -> ip_sum = sum;
-                /* update transport layer checksums */
-                udp_tcp_checksum(header,ntohs(header->ip_len)-sizeof(uint32_t)*header->ip_hl);
-        }
+        replace_ip_checksum(new_packet);
+        replace_transport_checksum(new_packet);
 
         return new_packet;