Attachment 2413 Details for Bug 2205 – Avoid early hostname lookup when hostname canonicalisation is not enabled

[patch] Avoid early hostname lookup when hostname canonicalisation is not enabled

delay-hostname-lookup-for-no-canonicalisation.diff (text/plain), 2.05 KB, created by Damien Miller on 2014-02-26 10:48:14 AEDT

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Creator: Damien Miller

Created: 2014-02-26 10:48:14 AEDT

Size: 2.05 KB

patch

obsolete

>Index: ssh.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/ssh.c,v
>retrieving revision 1.400
>diff -u -p -r1.400 ssh.c
>--- ssh.c	23 Feb 2014 20:11:36 -0000	1.400
>+++ ssh.c	25 Feb 2014 23:47:30 -0000
>@@ -871,12 +871,20 @@ main(int ac, char **av)
> 		addrs = resolve_canonicalize(&host, options.port);
> 
> 	/*
>-	 * If canonicalization not requested, or if it failed then try to
>-	 * resolve the bare hostname name using the system resolver's usual
>-	 * search rules. Skip the lookup if a ProxyCommand is being used
>-	 * unless the user has specifically requested canonicalisation.
>+	 * If CanonicalizePermittedCNAMEs have been specified but
>+	 * other canonicalization did not happen (by not being requested
>+	 * or by failing with fallback) then the hostname may still be changed
>+	 * as a result of CNAME following. 
>+	 *
>+	 * Try to resolve the bare hostname name using the system resolver's
>+	 * usual search rules and then apply the CNAME follow rules.
>+	 *
>+	 * Skip the lookup if a ProxyCommand is being used unless the user
>+	 * has specifically requested canonicalisation for this case via
>+	 * CanonicalizeHostname=always
> 	 */
>-	if (addrs == NULL && (option_clear_or_none(options.proxy_command) ||
>+	if (addrs == NULL && options.num_permitted_cnames != 0 &&
>+	    (option_clear_or_none(options.proxy_command) ||
>             options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
> 		if ((addrs = resolve_host(host, options.port, 1,
> 		    cname, sizeof(cname))) == NULL)
>@@ -967,6 +975,16 @@ main(int ac, char **av)
> 		fatal("No ControlPath specified for \"-O\" command");
> 	if (options.control_path != NULL)
> 		muxclient(options.control_path);
>+
>+	/*
>+	 * If hostname canonicalisation was not enabled, then we may not
>+	 * have yet resolved the hostname. Do so now.
>+	 */
>+	if (addrs == NULL && options.proxy_command == NULL) {
>+		if ((addrs = resolve_host(host, options.port, 1,
>+		    cname, sizeof(cname))) == NULL)
>+			cleanup_exit(255); /* resolve_host logs the error */
>+	}
> 
> 	timeout_ms = options.connection_timeout * 1000;
>

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dtucker: ok+

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Attachments on bug 2205: 2413