Nanosec accurate packet processing

src/common/timer.c

@@ -92,7 +92,7 @@ init_timestamp(struct timespec *timestamp)
 }
 
 int get_current_time(struct timespec *ts){
-    #ifdef _POSIX_C_SOURCE >= 199309L
+    #if defined _POSIX_C_SOURCE  && _POSIX_C_SOURCE >= 199309L
         return clock_gettime(CLOCK_REALTIME, ts);
     #else
         struct timeval tv;

src/defines.h.in

@@ -358,6 +358,13 @@ typedef u_int32_t uint32_t
         (a)->tv_nsec = (b)->tv_nsec;        \
     } while(0)
 
+/* libpcap puts nanosec values in tv_usec when pcap file is read with nanosec precision*/
+#define TIMEVAL_AS_TIMESPEC_SET(a, b)       \
+    do {                                    \
+        (a)->tv_sec = (b)->tv_sec;          \
+        (a)->tv_nsec = (b)->tv_usec;        \
+    } while(0)
+
 /* 
  * Help suppress some compiler warnings
  * No problem if variable is actually used 

src/replay.c

@@ -125,7 +125,7 @@ replay_file(tcpreplay_t *ctx, int idx)
 
     /* read from pcap file if we haven't cached things yet */
     if (!ctx->options->preload_pcap) {
-        if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
+        if ((pcap = pcap_open_offline_with_tstamp_precision(path, PCAP_TSTAMP_PRECISION_NANO, ebuf)) == NULL) {
             tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
             return -1;
         }
@@ -140,10 +140,10 @@ replay_file(tcpreplay_t *ctx, int idx)
 
     } else {
         if (!ctx->options->file_cache[idx].cached) {
-            if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
-                tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
-                return -1;
-            }
+        if ((pcap = pcap_open_offline_with_tstamp_precision(path, PCAP_TSTAMP_PRECISION_NANO, ebuf)) == NULL) {
+            tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
+            return -1;
+        }
             ctx->options->file_cache[idx].dlt = pcap_datalink(pcap);
         }
     }
@@ -152,10 +152,10 @@ replay_file(tcpreplay_t *ctx, int idx)
     if (ctx->options->verbose) {
         /* in cache mode, we may not have opened the file */
         if (pcap == NULL)
-            if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
-               tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
-               return -1;
-            }
+        if ((pcap = pcap_open_offline_with_tstamp_precision(path, PCAP_TSTAMP_PRECISION_NANO, ebuf)) == NULL) {
+            tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
+            return -1;
+        }
 
         ctx->options->file_cache[idx].dlt = pcap_datalink(pcap);
         /* init tcpdump */

src/send_packets.c

@@ -316,8 +316,7 @@ static void increment_iteration(tcpreplay_t *ctx)
 void
 send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
 {   
-    struct timeval last_pkt_ts;
-    struct timespec now, print_delta;
+    struct timespec now, print_delta, last_pkt_ts, pkthdr_ts;
     tcpreplay_opt_t *options = ctx->options;
     tcpreplay_stats_t *stats = &ctx->stats;
     COUNTER packetnum = 0;
@@ -350,7 +349,7 @@ send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
     }
 
     ctx->skip_packets = 0;
-    timerclear(&last_pkt_ts);
+    timesclear(&last_pkt_ts);
     if (options->limit_time > 0)
         end_us = TIMESPEC_TO_MICROSEC(&stats->start_time) +
             SEC_TO_MICROSEC(options->limit_time);
@@ -369,7 +368,7 @@ send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
      */
     while (!ctx->abort &&
             (pktdata = get_next_packet(ctx, pcap, &pkthdr, idx, prev_packet)) != NULL) {
-
+        TIMEVAL_AS_TIMESPEC_SET(&pkthdr_ts, &pkthdr.ts); // libpcap puts nanosec values in tv_usec
         now_is_now = false;
         packetnum++;
 #if defined TCPREPLAY || defined TCPREPLAY_EDIT
@@ -429,20 +428,20 @@ send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
              * time stamping is expensive, but now is the
              * time to do it.
              */
-            dbgx(4, "This packet time: " TIMEVAL_FORMAT, pkthdr.ts.tv_sec,
-                    pkthdr.ts.tv_usec);
+            dbgx(4, "This packet time: " TIMESPEC_FORMAT, pkthdr_ts.tv_sec,
+                    pkthdr_ts.tv_nsec);
             skip_length = 0;
             ctx->skip_packets = 0;
 
             if (options->speed.mode == speed_multiplier) {
-                if (!timerisset(&last_pkt_ts)) {
-                    TIMEVAL_SET(&last_pkt_ts, &pkthdr.ts);
-                } else if (timercmp(&pkthdr.ts, &last_pkt_ts, >)) {
-                    struct timeval delta;
-
-                    timersub(&pkthdr.ts, &last_pkt_ts, &delta);
-                    timeradd_timeval_timespec(&stats->pkt_ts_delta, &delta, &stats->pkt_ts_delta);
-                    TIMEVAL_SET(&last_pkt_ts, &pkthdr.ts);
+                if (!timesisset(&last_pkt_ts)) {
+                    TIMESPEC_SET(&last_pkt_ts, &pkthdr_ts);
+                } else if (timescmp(&pkthdr_ts, &last_pkt_ts, >)) {
+                    struct timespec delta;
+
+                    timessub(&pkthdr_ts, &last_pkt_ts, &delta);
+                    timeradd_timespec(&stats->pkt_ts_delta, &delta, &stats->pkt_ts_delta);
+                    TIMESPEC_SET(&last_pkt_ts, &pkthdr_ts);
                 }
             }
 
@@ -999,7 +998,7 @@ static void calc_sleep_time(tcpreplay_t *ctx, struct timespec *pkt_ts_delta,
         if (timescmp(pkt_ts_delta, time_delta, >)) {
             /* pkt_time_delta has increased, so handle normally */
             timessub(pkt_ts_delta, time_delta, &nap_for);
-            TIMESPEC_SET(&nap_for, &ctx->nap);
+            TIMESPEC_SET(&ctx->nap, &nap_for);
             dbgx(3, "original packet delta time: " TIMESPEC_FORMAT,
                     ctx->nap.tv_sec, ctx->nap.tv_nsec);
             timesdiv_float(&ctx->nap, options->speed.multiplier);
@@ -1117,8 +1116,9 @@ static void tcpr_sleep(tcpreplay_t *ctx, sendpacket_t *sp,
 
 
     /* don't sleep if nap = {0, 0} */
-    if (!timesisset(nap_this_time))
+    if (!timesisset(nap_this_time)){
         return;
+    }
 
     /* do we need to limit the total time we sleep? */
     if (timesisset(&(options->maxsleep)) && (timescmp(nap_this_time, &(options->maxsleep), >))) {

src/sleep.h

@@ -57,9 +57,9 @@ static inline void
 nanosleep_sleep(sendpacket_t *sp _U_, const struct timespec *nap,
         struct timespec *now,  bool flush _U_)
 {
-    #ifdef _POSIX_C_SOURCE >= 200112L
         struct timespec sleep_until;
         timeradd_timespec(now, nap, &sleep_until);
+    #if defined _POSIX_C_SOURCE  && _POSIX_C_SOURCE >= 200112L
         clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &sleep_until, NULL);
     #else
         nanosleep(nap, NULL);