Bow to tradition and correctly implement the bogus-but-hallowed semantics

of getsockopt never telling how much it might have copied if only the
buffer were big enough.

1 files changed, 6 insertions, 5 deletions

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index defd2a8..05d312f 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
- *	$Id: uipc_socket.c,v 1.43 1998/08/23 03:06:59 wollman Exp $
+ *	$Id: uipc_socket.c,v 1.44 1998/08/31 15:34:55 wollman Exp $
  */
 
 #include <sys/param.h>
@@ -1078,13 +1078,14 @@ sooptcopyout(sopt, buf, len)
 	/*
 	 * Documented get behavior is that we always return a value,
 	 * possibly truncated to fit in the user's buffer.
-	 * We leave the correct length in sopt->sopt_valsize,
-	 * to be copied out in getsockopt().  Note that this
-	 * interface is not idempotent; the entire answer must
+	 * Traditional behavior is that we always tell the user
+	 * precisely how much we copied, rather than something useful
+	 * like the total amount we had available for her.
+	 * Note that this interface is not idempotent; the entire answer must
 	 * generated ahead of time.
 	 */
 	valsize = min(len, sopt->sopt_valsize);
-	sopt->sopt_valsize = len;
+	sopt->sopt_valsize = valsize;
 	if (sopt->sopt_val != 0) {
 		if (sopt->sopt_p != 0)
 			error = copyout(buf, sopt->sopt_val, valsize);