From 853765954e6f38d967bed79ba7fb46e61f48311b Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Thu, 1 Nov 2007 15:51:43 +0000
Subject: [PATCH] Fixed bug #21181: On active open, the initial congestion
 window was calculated based on the configured TCP_MSS, not on the MSS option
 received with SYN+ACK.

---
 CHANGELOG         | 5 +++++
 src/core/tcp_in.c | 8 +++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index da2c6105..0344751c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -435,6 +435,11 @@ HISTORY
 
   ++ Bug fixes:
 
+  2007-10-09 Simon Goldschmidt
+  * tcp_in.c: Fixed bug #21181: On active open, the initial congestion window was
+    calculated based on the configured TCP_MSS, not on the MSS option received
+    with SYN+ACK.
+
   2007-10-09 Simon Goldschmidt
   * udp.c, inet.c, inet.h: Fixed UDPLite: send: Checksum was always generated too
     short and also was generated wrong if checksum coverage != tot_len;
diff --git a/src/core/tcp_in.c b/src/core/tcp_in.c
index fa061f21..369f0b7f 100644
--- a/src/core/tcp_in.c
+++ b/src/core/tcp_in.c
@@ -517,6 +517,11 @@ tcp_process(struct tcp_pcb *pcb)
       pcb->snd_wnd = tcphdr->wnd;
       pcb->snd_wl1 = seqno - 1; /* initialise to seqno - 1 to force window update */
       pcb->state = ESTABLISHED;
+
+      /* Parse any options in the SYNACK before using pcb->mss since that
+       * can be changed by the received options! */
+      tcp_parseopt(pcb);
+
       pcb->cwnd = ((pcb->cwnd == 1) ? (pcb->mss * 2) : pcb->mss);
       LWIP_ASSERT("pcb->snd_queuelen > 0", (pcb->snd_queuelen > 0));
       --pcb->snd_queuelen;
@@ -533,9 +538,6 @@ tcp_process(struct tcp_pcb *pcb)
 
       tcp_seg_free(rseg);
 
-      /* Parse any options in the SYNACK. */
-      tcp_parseopt(pcb);
-
       /* Call the user specified function to call when sucessfully
        * connected. */
       TCP_EVENT_CONNECTED(pcb, ERR_OK, err);