Changeset 6d9bd23 for tools/tracereplay

Timestamp:

11/26/09 17:11:40 (11 years ago)

Author:

Andreas Löf <andreas.lof@…>

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:

0f2e206

Parents:

58e2f74

Message:

added options for setting the destination ethernet address to broadcast.
added option to set snaplength

tidied up code and added some comments

File:

• tools/tracereplay/tracereplay.c (modified) (14 diffs)

tools/tracereplay/tracereplay.c

@@ -11 +11 @@
 
  */
-
-
 
 
@@ -27 +25 @@
 #define FCS_SIZE 4
 
-
-
-
-/* This function assumes that the relevant fields have been zeroed out. RFC 1071*/
+int broadcast;
+
+/* 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;
@@ -50 +48 @@
   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) {
@@ -58 +62 @@
   uint16_t * check = NULL;
   uint16_t tsum = 0;
-
+  void * transportheader = NULL;
 
   sum += (uint16_t) ~checksum(&ip->ip_src.s_addr,sizeof(uint32_t));
@@ -72 +76 @@
   sum += (uint16_t) ~checksum(&temp,sizeof(uint16_t));
 
-  void * transportheader = trace_get_payload_from_ip(ip,NULL,NULL);
-
+  transportheader = trace_get_payload_from_ip(ip,NULL,NULL);
+
+  /* UDP */
   if(protocol == 17 ) {
     libtrace_udp_t * udp_header = transportheader;
@@ -80 +85 @@
     tsum = checksum(transportheader, length);
   }
+  /* TCP */
   else if(protocol == 6) {
     libtrace_tcp_t * tcp_header = transportheader;
@@ -101 +107 @@
 }
 
-
+/*
+  Create a copy of the packet that can be written to the output URI.
+  if the packet is IPv4 the checksum will be recalculated to account for
+  cryptopan. Same for TCP and UDP. No other protocols are supported at the 
+  moment.
+ */
 static libtrace_packet_t * per_packet(libtrace_packet_t *packet) {
   uint32_t remaining = 0;  
   libtrace_linktype_t linktype = 0;
-  void * pkt_buffer = trace_get_packet_buffer(packet,&linktype,&remaining);
-  remaining = 0;
   libtrace_ip_t * header = NULL;
   uint16_t sum = 0;
-  libtrace_packet_t *new_packet = trace_create_packet();
-  
-  size_t wire_length = trace_get_wire_length(packet);
-
+  libtrace_packet_t *new_packet;
+  size_t wire_length;
+  void * pkt_buffer;
+  void * l2_header;
+  libtrace_ether_t * ether_header;
+  int i;
+
+  pkt_buffer = trace_get_packet_buffer(packet,&linktype,&remaining);
+  remaining = 0;
+  new_packet = trace_create_packet();
+  
+  wire_length = trace_get_wire_length(packet);
+
+  /* if it's ehternet we don't want to add space for the FCS that will
+     be appended. */
   if(linktype == TRACE_TYPE_ETH || linktype == TRACE_TYPE_80211) {
     wire_length -= FCS_SIZE;
@@ -118 +138 @@
 
   trace_construct_packet(new_packet,linktype,pkt_buffer,wire_length);
-  
-
+
+
+  if(broadcast) {
+    l2_header = trace_get_layer2(new_packet,&linktype,&remaining);
+    if(linktype == TRACE_TYPE_ETH){
+      ether_header = (libtrace_ether_t *) l2_header;
+      for(i = 0; i < 6; i++) {
+        ether_header -> ether_dhost[i] = 0xFF;
+      }
+    }
+    
+  }
+
+  
+  
   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);
   }
@@ -185 +220 @@
 
 static void usage(char * argv) {
-        fprintf(stderr, "usage: %s [options] libtraceuri outputuri...\n", argv);
+        fprintf(stderr, "usage: %s [options] inputuri outputuri...\n", argv);
         fprintf(stderr, " --filter bpfexpr\n");
         fprintf(stderr, " -f bpfexpr\n");
         fprintf(stderr, "\t\tApply a bpf filter expression\n");
+        fprintf(stderr, " -s snaplength\n");
+        fprintf(stderr, " --snaplength snaplength\n");
+        fprintf(stderr, "\t\tTruncate the packets read from inputuri to <snaplength>\n");
+        fprintf(stderr, " -b\n");
+        fprintf(stderr, " --broadcast\n");
+        fprintf(stderr, "\t\tSend ethernet frames to broadcast address\n");
+
 }
 
@@ -199 +241 @@
         int psize = 0;
         char *uri = 0;
+        libtrace_packet_t * new;
+        int snaplen = 0;
+        
 
         while(1) {
@@ -205 +250 @@
                         { "filter",     1, 0, 'f'},
                         { "help",       0, 0, 'h'},
+                        { "snaplen",    1, 0, 's'},
+                        { "broadcast",  0, 0, 'b'},
                         { NULL,         0, 0, 0}
                 };
 
-                int c = getopt_long(argc, argv, "f:",
+                int c = getopt_long(argc, argv, "bhs:f:",
                                 long_options, &option_index);
 
@@ -215 +262 @@
 
                 switch (c) {
-                        case 'f':
-                                filter = trace_create_filter(optarg);
-                                break;
-                        case 'h':
-                                usage(argv[0]);
-                                return 1;
-                        default:
-                                fprintf(stderr, "Unknown option: %c\n", c);
+                case 'f':
+                  filter = trace_create_filter(optarg);
+                  break;
+                case 's':
+                  snaplen = atoi(optarg);
+                  break;
+
+                case 'b':
+                  broadcast = 1;
+                  break;
+                  
+                case 'h':
+                  
+                  usage(argv[0]);
+                  return 1;
+                default:
+                  fprintf(stderr, "Unknown option: %c\n", c);
                 }
         }
@@ -246 +302 @@
         }
 
+        /*apply snaplength */
+        if(snaplen) {
+          if(trace_config(trace,TRACE_OPTION_SNAPLEN,&snaplen)) {
+            trace_perror(trace,"error setting snaplength, proceeding anyway");
+          }
+        }
+
         /* apply filter */
         if(filter) {
@@ -281 +344 @@
 
                 /* Got a packet - let's do something with it */
-                libtrace_packet_t * new = per_packet(packet);
+                new = per_packet(packet);
 
                 if (trace_write_packet(output, new) < 0) {