Attachment 2466 Details for Bug 2267 – attempt #2

[patch] attempt #2

canon2.diff (text/plain), 16.32 KB, created by Damien Miller on 2014-09-01 14:12:17 AEST

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Creator: Damien Miller

Created: 2014-09-01 14:12:17 AEST

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patch

obsolete

>Index: ssh_config.5
>===================================================================
>RCS file: /var/cvs/openssh/ssh_config.5,v
>retrieving revision 1.191
>diff -u -p -r1.191 ssh_config.5
>--- ssh_config.5	18 Jul 2014 04:11:26 -0000	1.191
>+++ ssh_config.5	1 Sep 2014 04:08:16 -0000
>@@ -65,7 +65,10 @@ The configuration files contain sections
> .Dq Host
> specifications, and that section is only applied for hosts that
> match one of the patterns given in the specification.
>-The matched host name is the one given on the command line.
>+The matched host name is usually the one given on the command line
>+(see the
>+.Cm RereadConfig
>+option for exceptions.)
> .Pp
> Since the first obtained value for each parameter is used, more
> host-specific declarations should be given near the beginning of the
>@@ -109,10 +112,12 @@ A single
> .Ql *
> as a pattern can be used to provide global
> defaults for all hosts.
>-The host is the
>+The host is usually the
> .Ar hostname
>-argument given on the command line (i.e. the name is not converted to
>-a canonicalized host name before matching).
>+argument given on the command line
>+(see the
>+.Cm RereadConfig
>+option for exceptions.)
> .Pp
> A pattern entry may be negated by prefixing it with an exclamation mark
> .Pq Sq !\& .
>@@ -134,19 +139,39 @@ or
> keyword) to be used only when the conditions following the
> .Cm Match
> keyword are satisfied.
>-Match conditions are specified using one or more keyword/criteria pairs
>+Match conditions are specified using one or more critera
> or the single token
> .Cm all
>-which matches all criteria.
>-The available keywords are:
>+which always matches.
>+The available criteria keywords are:
>+.Cm canonical ,
> .Cm exec ,
> .Cm host ,
> .Cm originalhost ,
> .Cm user ,
> and
> .Cm localuser .
>+The
>+.Cm all
>+criteria must appear alone.
>+Other criteria may be combined arbitrarily.
>+All criteria but
>+.Cm all
>+and
>+.Cm canonical
>+require an argument.
>+Criteria may be negated by prepending an exclamation mark
>+.Pq Sq !\& .
> .Pp
> The
>+.Cm canonical
>+keywork matches only when the configuration file is being re-parsed
>+after hostname canonicalization (see the
>+.Cm CanonicalizeHostname
>+option.)
>+This may be useful to specify conditions that work with canonical host
>+names only.
>+The
> .Cm exec
> keyword executes the specified command under the user's shell.
> If the command returns a zero exit status then the condition is considered true.
>@@ -775,6 +800,12 @@ The default is the name given on the com
> Numeric IP addresses are also permitted (both on the command line and in
> .Cm HostName
> specifications).
>+.Pp
>+If this option is enabled and results in the target hostname
>+changing, then the configuration files are processed again using the new
>+target name to pick up any new configuration in matching
>+.Cm Host
>+stanzas.
> .It Cm IdentitiesOnly
> Specifies that
> .Xr ssh 1
>@@ -1204,6 +1235,27 @@ will only succeed if the server's
> .Cm GatewayPorts
> option is enabled (see
> .Xr sshd_config 5 ) .
>+.It Cm RereadConfig
>+Controls whether
>+.Xr ssh 1
>+re-reads its configuration files a second time.
>+Re-reading the configuration files may allow
>+.Cm Host
>+and
>+.Cm Match
>+blocks to pick up changes to the target host name caused by
>+hostname canonicalisation or
>+.Cm HostName
>+directives.
>+The argument may be one of
>+.Dq no
>+to indicate that the configuration should never be re-read,
>+.Dq yes
>+to always re-read the configuration, or
>+.Dq if-canon
>+to only re-read the configuration if hostname canonicalisation is enabled.
>+The default is
>+.Dq if-canon .
> .It Cm RequestTTY
> Specifies whether to request a pseudo-tty for the session.
> The argument may be one of:
>Index: ssh.c
>===================================================================
>RCS file: /var/cvs/openssh/ssh.c,v
>retrieving revision 1.405
>diff -u -p -r1.405 ssh.c
>--- ssh.c	18 Jul 2014 05:04:11 -0000	1.405
>+++ ssh.c	1 Sep 2014 04:08:17 -0000
>@@ -384,27 +384,29 @@ resolve_canonicalize(char **hostp, int p
>  * file if the user specifies a config file on the command line.
>  */
> static void
>-process_config_files(struct passwd *pw)
>+process_config_files(const char *host_arg, struct passwd *pw, int post_canon)
> {
> 	char buf[MAXPATHLEN];
> 	int r;
> 
> 	if (config != NULL) {
> 		if (strcasecmp(config, "none") != 0 &&
>-		    !read_config_file(config, pw, host, &options,
>-		    SSHCONF_USERCONF))
>+		    !read_config_file(config, pw, host, host_arg, &options,
>+		    SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
> 			fatal("Can't open user config file %.100s: "
> 			    "%.100s", config, strerror(errno));
> 	} else {
> 		r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
> 		    _PATH_SSH_USER_CONFFILE);
> 		if (r > 0 && (size_t)r < sizeof(buf))
>-			(void)read_config_file(buf, pw, host, &options,
>-			     SSHCONF_CHECKPERM|SSHCONF_USERCONF);
>+			(void)read_config_file(buf, pw, host, host_arg,
>+			    &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
>+			    (post_canon ? SSHCONF_POSTCANON : 0));
> 
> 		/* Read systemwide configuration file after user config. */
>-		(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, host,
>-		    &options, 0);
>+		(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
>+		    host, host_arg, &options,
>+		    post_canon ? SSHCONF_POSTCANON : 0);
> 	}
> }
> 
>@@ -788,9 +790,9 @@ main(int ac, char **av)
> 			break;
> 		case 'o':
> 			line = xstrdup(optarg);
>-			if (process_config_line(&options, pw, host ? host : "",
>-			    line, "command-line", 0, NULL, SSHCONF_USERCONF)
>-			    != 0)
>+			if (process_config_line(&options, pw,
>+			    host ? host : "", host ? host : "", line,
>+			    "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
> 				exit(255);
> 			free(line);
> 			break;
>@@ -899,7 +901,7 @@ main(int ac, char **av)
> 		);
> 
> 	/* Parse the configuration files */
>-	process_config_files(pw);
>+	process_config_files(host_arg, pw, 0);
> 
> 	/* Hostname canonicalisation needs a few options filled. */
> 	fill_default_options_for_canonicalization(&options);
>@@ -944,13 +946,10 @@ main(int ac, char **av)
> 			check_follow_cname(&host, cname);
> 	}
> 
>-	/*
>-	 * If the target hostname has changed as a result of canonicalisation
>-	 * then re-parse the configuration files as new stanzas may match.
>-	 */
>-	if (strcasecmp(host_arg, host) != 0) {
>-		debug("Hostname has changed; re-reading configuration");
>-		process_config_files(pw);
>+	if (options.reread_config == 1 || (options.reread_config == 2 &&
>+	    options.canonicalize_hostname != 0)) {
>+		debug("Re-reading configuration");
>+		process_config_files(host_arg, pw, 1);
> 	}
> 
> 	/* Fill configuration defaults. */
>Index: readconf.c
>===================================================================
>RCS file: /var/cvs/openssh/readconf.c,v
>retrieving revision 1.203
>diff -u -p -r1.203 readconf.c
>--- readconf.c	18 Jul 2014 04:11:26 -0000	1.203
>+++ readconf.c	1 Sep 2014 04:08:18 -0000
>@@ -150,7 +150,7 @@ typedef enum {
> 	oKexAlgorithms, oIPQoS, oRequestTTY, oIgnoreUnknown, oProxyUseFdpass,
> 	oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
> 	oCanonicalizeFallbackLocal, oCanonicalizePermittedCNAMEs,
>-	oStreamLocalBindMask, oStreamLocalBindUnlink,
>+	oStreamLocalBindMask, oStreamLocalBindUnlink, oRereadConfig,
> 	oIgnoredUnknownOption, oDeprecated, oUnsupported
> } OpCodes;
> 
>@@ -266,6 +266,7 @@ static struct {
> 	{ "streamlocalbindmask", oStreamLocalBindMask },
> 	{ "streamlocalbindunlink", oStreamLocalBindUnlink },
> 	{ "ignoreunknown", oIgnoreUnknown },
>+	{ "rereadconfig", oRereadConfig },
> 
> 	{ NULL, oBadOption }
> };
>@@ -476,11 +477,12 @@ execute_in_shell(const char *cmd)
>  */
> static int
> match_cfg_line(Options *options, char **condition, struct passwd *pw,
>-    const char *host_arg, const char *filename, int linenum)
>+    const char *host_arg, const char *original_host, int post_canon,
>+    const char *filename, int linenum)
> {
>-	char *arg, *attrib, *cmd, *cp = *condition, *host;
>+	char *arg, *oattrib, *attrib, *cmd, *cp = *condition, *host, *criteria;
> 	const char *ruser;
>-	int r, port, result = 1, attributes = 0;
>+	int r, port, this_result, result = 1, attributes = 0, negate;
> 	size_t len;
> 	char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
> 
>@@ -497,21 +499,38 @@ match_cfg_line(Options *options, char **
> 	} else
> 		host = xstrdup(host_arg);
> 
>-	debug3("checking match for '%s' host %s", cp, host);
>-	while ((attrib = strdelim(&cp)) && *attrib != '\0') {
>+	debug2("checking match for '%s' host %s originally %s",
>+	    cp, host, original_host);
>+	while ((oattrib = attrib = strdelim(&cp)) && *attrib != '\0') {
>+		criteria = NULL;
>+		this_result = 1;
> 		attributes++;
>+		negate = attrib[0] == '!';
>+		if (negate)
>+			attrib++;
>+		/* criteria "all" and "canonical" have no argument */
> 		if (strcasecmp(attrib, "all") == 0) {
> 			if (attributes != 1 ||
> 			    ((arg = strdelim(&cp)) != NULL && *arg != '\0')) {
>-				error("'all' cannot be combined with other "
>-				    "Match attributes");
>+				error("%.200s line %d: '%s' cannot be combined "
>+				    "with other Match attributes",
>+				    filename, linenum, oattrib);
> 				result = -1;
> 				goto out;
> 			}
> 			*condition = cp;
>-			result = 1;
>+			result = negate ? 0 : 1;
> 			goto out;
>+		} else if (strcasecmp(attrib, "canonical") == 0) {
>+			r = !!post_canon;  /* force bitmask member to boolean */
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
>+			debug3("%.200s line %d: %smatched '%s'",
>+			    filename, linenum,
>+			    this_result ? "" : "not ", oattrib);
>+			continue;
> 		}
>+		/* All other criteria require an argument */
> 		if ((arg = strdelim(&cp)) == NULL || *arg == '\0') {
> 			error("Missing Match criteria for %s", attrib);
> 			result = -1;
>@@ -519,31 +538,25 @@ match_cfg_line(Options *options, char **
> 		}
> 		len = strlen(arg);
> 		if (strcasecmp(attrib, "host") == 0) {
>-			if (match_hostname(host, arg, len) != 1)
>-				result = 0;
>-			else
>-				debug("%.200s line %d: matched 'Host %.100s' ",
>-				    filename, linenum, host);
>+			criteria = xstrdup(host);
>+			r = match_hostname(host, arg, len) == 1;
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
> 		} else if (strcasecmp(attrib, "originalhost") == 0) {
>-			if (match_hostname(host_arg, arg, len) != 1)
>-				result = 0;
>-			else
>-				debug("%.200s line %d: matched "
>-				    "'OriginalHost %.100s' ",
>-				    filename, linenum, host_arg);
>+			criteria = xstrdup(original_host);
>+			r = match_hostname(original_host, arg, len) == 1;
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
> 		} else if (strcasecmp(attrib, "user") == 0) {
>-			if (match_pattern_list(ruser, arg, len, 0) != 1)
>-				result = 0;
>-			else
>-				debug("%.200s line %d: matched 'User %.100s' ",
>-				    filename, linenum, ruser);
>+			criteria = xstrdup(ruser);
>+			r = match_pattern_list(ruser, arg, len, 0) == 1;
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
> 		} else if (strcasecmp(attrib, "localuser") == 0) {
>-			if (match_pattern_list(pw->pw_name, arg, len, 0) != 1)
>-				result = 0;
>-			else
>-				debug("%.200s line %d: matched "
>-				    "'LocalUser %.100s' ",
>-				    filename, linenum, pw->pw_name);
>+			criteria = xstrdup(pw->pw_name);
>+			r = match_pattern_list(pw->pw_name, arg, len, 0) == 1;
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
> 		} else if (strcasecmp(attrib, "exec") == 0) {
> 			if (gethostname(thishost, sizeof(thishost)) == -1)
> 				fatal("gethostname: %s", strerror(errno));
>@@ -556,45 +569,46 @@ match_cfg_line(Options *options, char **
> 			    "d", pw->pw_dir,
> 			    "h", host,
> 			    "l", thishost,
>-			    "n", host_arg,
>+			    "n", original_host,
> 			    "p", portstr,
> 			    "r", ruser,
> 			    "u", pw->pw_name,
> 			    (char *)NULL);
> 			if (result != 1) {
> 				/* skip execution if prior predicate failed */
>-				debug("%.200s line %d: skipped exec \"%.100s\"",
>-				    filename, linenum, cmd);
>-			} else {
>-				r = execute_in_shell(cmd);
>-				if (r == -1) {
>-					fatal("%.200s line %d: match exec "
>-					    "'%.100s' error", filename,
>-					    linenum, cmd);
>-				} else if (r == 0) {
>-					debug("%.200s line %d: matched "
>-					    "'exec \"%.100s\"'", filename,
>-					    linenum, cmd);
>-				} else {
>-					debug("%.200s line %d: no match "
>-					    "'exec \"%.100s\"'", filename,
>-					    linenum, cmd);
>-					result = 0;
>-				}
>+				debug3("%.200s line %d: skipped exec "
>+				    "\"%.100s\"", filename, linenum, cmd);
>+				free(cmd);
>+				continue;
> 			}
>+			r = execute_in_shell(cmd);
>+			if (r == -1) {
>+				fatal("%.200s line %d: match exec "
>+				    "'%.100s' error", filename,
>+				    linenum, cmd);
>+			}
>+			criteria = xstrdup(cmd);
> 			free(cmd);
>+			/* Force exit status to boolean */
>+			r = r == 0;
>+			if (r == (negate ? 1 : 0))
>+				this_result = result = 0;
> 		} else {
> 			error("Unsupported Match attribute %s", attrib);
> 			result = -1;
> 			goto out;
> 		}
>+		debug3("%.200s line %d: %smatched '%s \"%.100s\"' ",
>+		    filename, linenum, this_result ? "": "not ",
>+		    oattrib, criteria);
>+		free(criteria);
> 	}
> 	if (attributes == 0) {
> 		error("One or more attributes required for Match");
> 		result = -1;
> 		goto out;
> 	}
>-	debug3("match %sfound", result ? "" : "not ");
>+	debug2("match %sfound", result ? "" : "not ");
> 	*condition = cp;
>  out:
> 	free(host);
>@@ -711,6 +725,14 @@ static const struct multistate multistat
> 	{ "always",			SSH_CANONICALISE_ALWAYS },
> 	{ NULL, -1 }
> };
>+static const struct multistate multistate_reread_config[] = {
>+	{ "true",			SSH_REREAD_YES },
>+	{ "false",			SSH_REREAD_NO },
>+	{ "yes",			SSH_REREAD_YES },
>+	{ "no",				SSH_REREAD_NO },
>+	{ "if-canon",			SSH_REREAD_CANON },
>+	{ NULL, -1 }
>+};
> 
> /*
>  * Processes a single option line as used in the configuration files. This
>@@ -719,7 +741,8 @@ static const struct multistate multistat
> #define WHITESPACE " \t\r\n"
> int
> process_config_line(Options *options, struct passwd *pw, const char *host,
>-    char *line, const char *filename, int linenum, int *activep, int userconfig)
>+    const char *original_host, char *line, const char *filename,
>+    int linenum, int *activep, int flags)
> {
> 	char *s, **charptr, *endofnumber, *keyword, *arg, *arg2;
> 	char **cpptr, fwdarg[256];
>@@ -947,7 +970,8 @@ parse_time:
> 			if (*intptr >= SSH_MAX_IDENTITY_FILES)
> 				fatal("%.200s line %d: Too many identity files specified (max %d).",
> 				    filename, linenum, SSH_MAX_IDENTITY_FILES);
>-			add_identity_file(options, NULL, arg, userconfig);
>+			add_identity_file(options, NULL,
>+			    arg, flags & SSHCONF_USERCONF);
> 		}
> 		break;
> 
>@@ -1195,8 +1219,8 @@ parse_int:
> 		if (cmdline)
> 			fatal("Host directive not supported as a command-line "
> 			    "option");
>-		value = match_cfg_line(options, &s, pw, host,
>-		    filename, linenum);
>+		value = match_cfg_line(options, &s, pw, host, original_host,
>+		    flags & SSHCONF_POSTCANON, filename, linenum);
> 		if (value < 0)
> 			fatal("%.200s line %d: Bad Match condition", filename,
> 			    linenum);
>@@ -1433,6 +1457,11 @@ parse_int:
> 		intptr = &options->fwd_opts.streamlocal_bind_unlink;
> 		goto parse_flag;
> 
>+	case oRereadConfig:
>+		intptr = &options->reread_config;
>+		multistate_ptr = multistate_reread_config;
>+		goto parse_multistate;
>+
> 	case oDeprecated:
> 		debug("%s line %d: Deprecated option \"%s\"",
> 		    filename, linenum, keyword);
>@@ -1444,7 +1473,7 @@ parse_int:
> 		return 0;
> 
> 	default:
>-		fatal("process_config_line: Unimplemented opcode %d", opcode);
>+		fatal("%s: Unimplemented opcode %d", __func__, opcode);
> 	}
> 
> 	/* Check that there is no garbage at end of line. */
>@@ -1464,7 +1493,7 @@ parse_int:
> 
> int
> read_config_file(const char *filename, struct passwd *pw, const char *host,
>-    Options *options, int flags)
>+    const char *original_host, Options *options, int flags)
> {
> 	FILE *f;
> 	char line[1024];
>@@ -1495,8 +1524,8 @@ read_config_file(const char *filename, s
> 	while (fgets(line, sizeof(line), f)) {
> 		/* Update line number counter. */
> 		linenum++;
>-		if (process_config_line(options, pw, host, line, filename,
>-		    linenum, &active, flags & SSHCONF_USERCONF) != 0)
>+		if (process_config_line(options, pw, host, original_host,
>+		    line, filename, linenum, &active, flags) != 0)
> 			bad_options++;
> 	}
> 	fclose(f);
>@@ -1609,6 +1638,7 @@ initialize_options(Options * options)
> 	options->canonicalize_max_dots = -1;
> 	options->canonicalize_fallback_local = -1;
> 	options->canonicalize_hostname = -1;
>+	options->reread_config = -1;
> }
> 
> /*
>@@ -1786,6 +1816,8 @@ fill_default_options(Options * options)
> 		options->canonicalize_fallback_local = 1;
> 	if (options->canonicalize_hostname == -1)
> 		options->canonicalize_hostname = SSH_CANONICALISE_NO;
>+	if (options->reread_config == -1)
>+		options->reread_config = SSH_REREAD_CANON;
> #define CLEAR_ON_NONE(v) \
> 	do { \
> 		if (option_clear_or_none(v)) { \

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Attachments on bug 2267: 2465 | 2466 | 2467 | 2469 | 2470