From 845ecc3d6bfe0df4d65bcd77ea634fa6c143583d Mon Sep 17 00:00:00 2001
From: wollman <wollman@FreeBSD.org>
Date: Sat, 9 May 1998 20:50:37 +0000
Subject: [PATCH] Documentation fix: delete references to T/TCP as they are not
 relevant to the case in question.  (Said case being quite clearly defined by
 the basic TCP specification, RFC 792.)

---
 usr.bin/fetch/fetch.1 | 33 +++++++++++++++++++++++++++------
 usr.bin/fetch/http.c  | 15 +++++++++------
 2 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/usr.bin/fetch/fetch.1 b/usr.bin/fetch/fetch.1
index ee254126e083..71d21505f397 100644
--- a/usr.bin/fetch/fetch.1
+++ b/usr.bin/fetch/fetch.1
@@ -1,4 +1,4 @@
-.\" $Id: fetch.1,v 1.20 1998/03/23 07:43:02 charnier Exp $
+.\" $Id: fetch.1,v 1.21 1998/05/09 07:33:09 fenner Exp $
 .Dd July 2, 1996
 .Dt FETCH 1
 .Os FreeBSD 2.2
@@ -100,9 +100,9 @@ under any circumstances, even if the transfer failed or was incomplete.
 .It Fl r
 Restart a previously interrupted transfer.
 .It Fl t
-Ensure that the use of T/TCP is not attempted for connections.  This is
-used to workaround bugs in some remote OS stacks that give improper
-replies to T/TCP connections.
+Work around a different set of buggy
+.Tn TCP
+implementations.
 .It Fl T Ar seconds
 Set timeout value to
 .Ar seconds.
@@ -198,7 +198,7 @@ realm is specified as
 .Sq Li \&* ,
 then it will match all realms not specified otherwise.
 .Pp
-For the
+The
 .Li basic
 authentication scheme uses two additional optional parameters; the
 first is a user name, and the second is the password associated with
@@ -328,6 +328,27 @@ authentication mode is implemented for
 .Tn HTTP .
 This should be replaced by digest authentication.
 .Pp
+Some 
+.Tn TCP
+implementations (other than
+.Fx ) 
+fail to correctly implement cases where the
+.Dv SYN
+and/or
+.Dv FIN
+control flags are specified in packets which also contain data.
 The
+.Sq Fl t
+flag works around the latter deficiency and the
+.Sq Fl b
+flag works around the former.  Since these are errors of the server's
+.Tn TCP
+stack, the best we can do is provide these workarounds.  Given a correct
+server, an optimal 
+.Tn HTTP
+transfer without
+.Fl t
+and
 .Fl b
-flag should not be necessary.
+involves a minimum of two round trips (for small replies), one less than
+other implementations.
diff --git a/usr.bin/fetch/http.c b/usr.bin/fetch/http.c
index 0c872093023b..7b9cb50216e0 100644
--- a/usr.bin/fetch/http.c
+++ b/usr.bin/fetch/http.c
@@ -26,7 +26,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: http.c,v 1.16 1997/11/22 01:00:42 fenner Exp $
+ *	$Id: http.c,v 1.17 1998/02/20 05:11:40 jb Exp $
  */
 
 #include <sys/types.h>
@@ -594,11 +594,14 @@ retry:
 	setup_sigalrm();
 	alarm(timo);
 
-	/* some hosts do not properly handle T/TCP connections.  If
-	 * sendmsg() is used to establish the connection, the OS may
-	 * choose to try to use one which could cause the transfer
-	 * to fail.  Doing a connect() first ensures that the OS
-	 * does not attempt T/TCP.
+	/*
+	 * Some hosts do not correctly handle data in SYN segments.
+	 * If no connect(2) is done, the TCP stack will send our
+	 * initial request as such a segment.  fs_use_connect works
+	 * around these broken server TCPs by avoiding this case.
+	 * It is not the default because we want to exercise this
+	 * code path, and in any case the majority of hosts handle
+	 * our default correctly.
 	 */
 	if (fs->fs_use_connect && (connect(s, (struct sockaddr *)&sin, 
                                    sizeof(struct sockaddr_in)) < 0)) {