Qt: modify RTT graph (handle GSO, SACK, etc), plus bug fixes

Modifications to RTT graph:
 - change x-axis to time (s) rather than sequence number
    [ avoids sequence number wraparound ambiguity, plus
       easier to correlate RTT changes to tcptrace graph ]
 - change RTT computation to properly handle acks to GSO packets
 - change RTT computation to take SACK blocks into account

Bug fixes:
 - eliminate potential memory leak if some packets are unacked
 - ensure RTT graph is shown if TCPGraph window is opened to it directly

Change-Id: I2bdcab97399ebde0f15c78fa19c882529a814580
Reviewed-on: https://code.wireshark.org/review/19662
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 21 insertions, 10 deletions

diff --git a/ui/tap-tcp-stream.c b/ui/tap-tcp-stream.c
index abf357683d..44115aa99f 100644
--- a/ui/tap-tcp-stream.c
+++ b/ui/tap-tcp-stream.c
@@ -364,31 +364,34 @@ select_tcpip_session(capture_file *cf, struct segment *hdrs)
     return th.tcphdrs[0];
 }
 
-int rtt_is_retrans(struct unack *list, unsigned int seqno)
+int rtt_is_retrans(struct rtt_unack *list, unsigned int seqno)
 {
-    struct unack *u;
+    struct rtt_unack *u;
 
     for (u=list; u; u=u->next) {
-        if (u->seqno == seqno)
+        if (tcp_seq_eq_or_after(seqno, u->seqno) &&
+            tcp_seq_before(seqno, u->end_seqno))
             return TRUE;
     }
     return FALSE;
 }
 
-struct unack *rtt_get_new_unack(double time_val, unsigned int seqno)
+struct rtt_unack *
+rtt_get_new_unack(double time_val, unsigned int seqno, unsigned int seglen)
 {
-    struct unack *u;
+    struct rtt_unack *u;
 
-    u = (struct unack * )g_malloc(sizeof(struct unack));
+    u = (struct rtt_unack * )g_malloc(sizeof(struct rtt_unack));
     u->next  = NULL;
     u->time  = time_val;
     u->seqno = seqno;
+    u->end_seqno = seqno + seglen;
     return u;
 }
 
-void rtt_put_unack_on_list(struct unack **l, struct unack *new_unack)
+void rtt_put_unack_on_list(struct rtt_unack **l, struct rtt_unack *new_unack)
 {
-    struct unack *u, *list = *l;
+    struct rtt_unack *u, *list = *l;
 
     for (u=list; u; u=u->next) {
         if (!u->next)
@@ -400,9 +403,9 @@ void rtt_put_unack_on_list(struct unack **l, struct unack *new_unack)
         *l = new_unack;
 }
 
-void rtt_delete_unack_from_list(struct unack **l, struct unack *dead)
+void rtt_delete_unack_from_list(struct rtt_unack **l, struct rtt_unack *dead)
 {
-    struct unack *u, *list = *l;
+    struct rtt_unack *u, *list = *l;
 
     if (!dead || !list)
         return;
@@ -421,6 +424,14 @@ void rtt_delete_unack_from_list(struct unack **l, struct unack *dead)
     }
 }
 
+void rtt_destroy_unack_list(struct rtt_unack **l ) {
+    while (*l) {
+        struct rtt_unack *head = *l;
+        *l = head->next;
+        g_free(head);
+    }
+}
+
 /*
  * Editor modelines
  *