bug#36660: 27.0.50; :nowait fails when failing over when using TLS

bug#36660: 27.0.50; :nowait fails when failing over when using TLS

[Robert Pluim]

The long version of this is at

<https://lists.gnu.org/archive/html/emacs-devel/2019-02/msg00588.html>

Short version: when opening a network connection using :nowait t, and
using TLS, failing over from one IP address to a second one fails,
because by the time Emacs tries to make the second connection, itʼs
deleted the TLS boot parameters it needs, so attempts to make a TCP
connection but using the original TLS port number.

Patch to follow once I get the bug number.

In GNU Emacs 27.0.50 (build 12, x86_64-apple-darwin18.6.0, NS appkit-1671.50 Version 10.14.5 (Build 18F132))
 of 2019-07-04 built on rpluim-mac
Repository revision: 9c2b1935a316a3d628255f83b26c6605189d2f62
Repository branch: master
Windowing system distributor 'Apple', version 10.3.1671
System Description:  Mac OS X 10.14.5

bug#36660: 27.0.50; :nowait fails when failing over when using TLS

[Robert Pluim]

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O frabjous day! What a bug number :-)


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From cfd2d8cbadc3c2b744e40c47cdce4344da1eef77 Mon Sep 17 00:00:00 2001
From: Robert Pluim <rpluim@gmail.com>
Date: Mon, 15 Jul 2019 13:04:59 +0200
Subject: [PATCH] Don't delete GnuTLS boot parameters too early
To: emacs-devel@gnu.org

When falling back from one IP address to another for the same host, we
need to keep the TLS boot parameters around until we've actually
managed to connect, otherwise the fallback connection(s) will use TCP
rather than TLS.  (Bug#36660)

* src/process.c (connect_network_socket): Don't delete the GnuTLS
boot parameters until after we've managed to connect at the IP
level.
---
 src/process.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/process.c b/src/process.c
index cab390c10c..23c9be2b7b 100644
--- a/src/process.c
+++ b/src/process.c
@@ -3682,11 +3682,14 @@ connect_network_socket (Lisp_Object proc, Lisp_Object addrinfos,
       Lisp_Object boot, params = p->gnutls_boot_parameters;
 
       boot = Fgnutls_boot (proc, XCAR (params), XCDR (params));
-      p->gnutls_boot_parameters = Qnil;
 
       if (p->gnutls_initstage == GNUTLS_STAGE_READY)
+        {
 	/* Run sentinels, etc. */
+          p->gnutls_boot_parameters = Qnil;
+
 	finish_after_tls_connection (proc);
+        }
       else if (p->gnutls_initstage != GNUTLS_STAGE_HANDSHAKE_TRIED)
 	{
 	  deactivate_process (proc);
-- 
2.21.0.419.gffac537e6c

bug#36660: 27.0.50; :nowait fails when failing over when using TLS

[Lars Ingebrigtsen]

Robert Pluim <rpluim@gmail.com> writes:

> O frabjous day! What a bug number :-)

Positively devilish.

>        boot = Fgnutls_boot (proc, XCAR (params), XCDR (params));
> -      p->gnutls_boot_parameters = Qnil;
>
>        if (p->gnutls_initstage == GNUTLS_STAGE_READY)
> +        {
>  	/* Run sentinels, etc. */
> +          p->gnutls_boot_parameters = Qnil;
> +
>  	finish_after_tls_connection (proc);
> +        }

Makes perfect sense; I've now applied it to the trunk.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#36660: 27.0.50; :nowait fails when failing over when using TLS

[Robert Pluim]

>>>>> On Mon, 15 Jul 2019 13:31:14 +0200, Lars Ingebrigtsen <larsi@gnus.org> said:
    Lars> Makes perfect sense; I've now applied it to the trunk.

That was unexpectedly quick, but welcome (although you trimmed my
explanation of the cause of the bug when you committed the patch. Did
I offend 'git apply' somewhere?).

Thanks

Robert

bug#36660: 27.0.50; :nowait fails when failing over when using TLS

[Lars Ingebrigtsen]

Robert Pluim <rpluim@gmail.com> writes:

> That was unexpectedly quick, but welcome (although you trimmed my
> explanation of the cause of the bug when you committed the patch. Did
> I offend 'git apply' somewhere?).

Oh, sorry.  I didn't use git apply; I used `M-m' in debbugs-gnu.  Looks
like it doesn't preserve all of the text before the patch -- needs some
tweaks.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no