---

yaml --- r: 24959 b: refs/heads/master c: c08e496 h: refs/heads/master i: 24957: 7ea0f56 24955: bb736eb 24951: 7c07c0d 24943: ba2e061 24927: cb18bfd 24895: aed9b2c 24831: f349d84 v: v3
git-mirror · Mar 31, 2006 · 45705f4 · 45705f4
1 parent 9c33682
commit 45705f4
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 56079431b6ba163df8ba26b3eccc82379f0c0ce4
+refs/heads/master: c08e49611a8b4e38a75bf217e1029a48faf10b82
diff --git a/trunk/net/core/sock.c b/trunk/net/core/sock.c
@@ -385,7 +385,21 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 				val = sysctl_rmem_max;
 set_rcvbuf:
 			sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
-			/* FIXME: is this lower bound the right one? */
+			/*
+			 * We double it on the way in to account for
+			 * "struct sk_buff" etc. overhead.   Applications
+			 * assume that the SO_RCVBUF setting they make will
+			 * allow that much actual data to be received on that
+			 * socket.
+			 *
+			 * Applications are unaware that "struct sk_buff" and
+			 * other overheads allocate from the receive buffer
+			 * during socket buffer allocation.
+			 *
+			 * And after considering the possible alternatives,
+			 * returning the value we actually used in getsockopt
+			 * is the most desirable behavior.
+			 */
 			if ((val * 2) < SOCK_MIN_RCVBUF)
 				sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
 			else