Merge pull request #699 from appneta/Bug_#674_multiplier_lt_1_fails

Bug #674 - Revert "send_packet: Avoid clock drift by using time since first packet"
appneta · Jan 28, 2022 · 266966f · 266966f
2 parents 22cecbb + b53d916
commit 266966f
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Showing 3 changed files with 14 additions and 27 deletions.
diff --git a/docs/CHANGELOG b/docs/CHANGELOG
@@ -3,11 +3,12 @@
     - add a security policy document (#689)
     - ability to specify directory of pcap files (#682)
     - incorrect PPS rate for long-running sessions (#679)
+    - revert #630 to fix --multiplier issues (#674)
     - option --skipbroadcast not working (#677)
     - latest macOS SDK selected by default (#668)
     - add feature VLAN Q-in-Q (#625)
 
-06/19/2021 Version 4.3.5-beta1
+06/19/2021 Version 4.3.5-beta1f
     - gcc 9.3 compiler warnings (#670)
     - installed netmap not automatically detected (#669)
     - heap-buffer-overflow with flow_decode() (#665)

diff --git a/src/common/utils.h b/src/common/utils.h
@@ -36,8 +36,6 @@ typedef struct {
     struct timeval end_time;
     struct timeval pkt_ts_delta;
     struct timeval last_print;
-    struct timeval first_packet_sent_wall_time;
-    struct timeval first_packet_pcap_timestamp;
     COUNTER flow_non_flow_packets;
     COUNTER flows;
     COUNTER flows_unique;

diff --git a/src/send_packets.c b/src/send_packets.c
@@ -351,7 +351,6 @@ send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
 
     ctx->skip_packets = 0;
     timerclear(&last_pkt_ts);
-    timerclear(&stats->first_packet_sent_wall_time);
     if (options->limit_time > 0)
         end_us = TIMEVAL_TO_MICROSEC(&stats->start_time) +
             SEC_TO_MICROSEC(options->limit_time);
@@ -436,23 +435,18 @@ send_packets(tcpreplay_t *ctx, pcap_t *pcap, int idx)
             ctx->skip_packets = 0;
 
             if (options->speed.mode == speed_multiplier) {
-                if(!timerisset(&stats->first_packet_sent_wall_time)) {
-                    /* We're sending the first packet, so we have an absolute time reference. */
-                    TIMEVAL_SET(&stats->first_packet_sent_wall_time, &now);
-                    TIMEVAL_SET(&stats->first_packet_pcap_timestamp, &pkthdr.ts);
-                }
-
                 if (!timerisset(&last_pkt_ts)) {
                     TIMEVAL_SET(&last_pkt_ts, &pkthdr.ts);
                 } else if (timercmp(&pkthdr.ts, &last_pkt_ts, >)) {
-                    /* pkt_ts_delta is the packet time stamp difference since the first packet */
-                    timersub(&pkthdr.ts, &stats->first_packet_pcap_timestamp, &stats->pkt_ts_delta);
-
-                    /* time_delta is the wall time difference since sending the first packet */
-                    timersub(&now, &stats->first_packet_sent_wall_time, &stats->time_delta);
+                    struct timeval delta;
 
+                    timersub(&pkthdr.ts, &last_pkt_ts, &delta);
+                    timeradd(&stats->pkt_ts_delta, &delta, &stats->pkt_ts_delta);
                     TIMEVAL_SET(&last_pkt_ts, &pkthdr.ts);
                 }
+
+                if (!timerisset(&stats->time_delta))
+                    TIMEVAL_SET(&stats->pkt_ts_delta, &stats->pkt_ts_delta);
             }
 
             if (!top_speed) {
@@ -602,7 +596,6 @@ send_dual_packets(tcpreplay_t *ctx, pcap_t *pcap1, int cache_file_idx1, pcap_t *
 
     ctx->skip_packets = 0;
     timerclear(&last_pkt_ts);
-    timerclear(&stats->first_packet_sent_wall_time);
     if (options->limit_time > 0)
         end_us = TIMEVAL_TO_MICROSEC(&stats->start_time) +
             SEC_TO_MICROSEC(options->limit_time);
@@ -718,23 +711,18 @@ send_dual_packets(tcpreplay_t *ctx, pcap_t *pcap1, int cache_file_idx1, pcap_t *
             ctx->skip_packets = 0;
 
             if (options->speed.mode == speed_multiplier) {
-                if(!timerisset(&stats->first_packet_sent_wall_time)) {
-                    /* We're sending the first packet, so we have an absolute time reference. */
-                    TIMEVAL_SET(&stats->first_packet_sent_wall_time, &now);
-                    TIMEVAL_SET(&stats->first_packet_pcap_timestamp, &pkthdr_ptr->ts);
-                }
-
                 if (!timerisset(&last_pkt_ts)) {
                     TIMEVAL_SET(&last_pkt_ts, &pkthdr_ptr->ts);
                 } else if (timercmp(&pkthdr_ptr->ts, &last_pkt_ts, >)) {
-                    /* pkt_ts_delta is the packet time stamp difference since the first packet */
-                    timersub(&pkthdr_ptr->ts, &stats->first_packet_pcap_timestamp, &stats->pkt_ts_delta);
-
-                    /* time_delta is the wall time difference since sending the first packet */
-                    timersub(&now, &stats->first_packet_sent_wall_time, &stats->time_delta);
+                    struct timeval delta;
 
+                    timersub(&pkthdr_ptr->ts, &last_pkt_ts, &delta);
+                    timeradd(&stats->pkt_ts_delta, &delta, &stats->pkt_ts_delta);
                     TIMEVAL_SET(&last_pkt_ts, &pkthdr_ptr->ts);
                 }
+
+                if (!timerisset(&stats->time_delta))
+                    TIMEVAL_SET(&stats->pkt_ts_delta, &stats->pkt_ts_delta);
             }
 
             if (!top_speed) {