From bc55d41b9a5c062c0b0b7ee9b8642369d88d614b Mon Sep 17 00:00:00 2001
From: david <david@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Thu, 2 Dec 2010 22:46:56 +0000
Subject: [PATCH] Add a comment explaining why we can unconditionally set the
 id and seq fields in build_icmp_raw, even though not all ICMP types have
 them. All the types handled by the function do have them, and in the same
 place.

---
 tcpip.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tcpip.cc b/tcpip.cc
index fae33915a..713db0ae9 100644
--- a/tcpip.cc
+++ b/tcpip.cc
@@ -635,7 +635,8 @@ u8 *build_icmp_raw(const struct in_addr *source,
     memset(datastart, 0, MIN(dlen, datalen));
   }
 
-  /* Fill out the ping packet */
+  /* Fill out the ping packet. All the ICMP types handled by this function have
+     the id and seq fields. */
   pingpkt.id = htons(id);
   pingpkt.seq = htons(seq);
   pingpkt.checksum = 0;