commit 9e34e0c59ab04514f9de9934a772283f7f372afe
Author: djm@openbsd.org <djm@openbsd.org>
Date: Fri Nov 23 05:08:07 2018 +0000
upstream: add a ssh_config "Match final" predicate
Matches in same pass as "Match canonical" but doesn't require
hostname canonicalisation be enabled. bz#2906 ok markus
OpenBSD-Commit-ID: fba1dfe9f6e0cabcd0e2b3be13f7a434199beffa
diff --git a/readconf.c b/readconf.c
index 7850f2f5..7331ef5a 100644
--- a/readconf.c
+++ b/readconf.c
@@ -133,10 +133,11 @@
static int read_config_file_depth(const char *filename, struct passwd *pw,
const char *host, const char *original_host, Options *options,
- int flags, int *activep, int depth);
+ int flags, int *activep, int *want_final_pass, int depth);
static int process_config_line_depth(Options *options, struct passwd *pw,
const char *host, const char *original_host, char *line,
- const char *filename, int linenum, int *activep, int flags, int depth);
+ const char *filename, int linenum, int *activep, int flags,
+ int *want_final_pass, int depth);
/* Keyword tokens. */
@@ -539,8 +540,8 @@ execute_in_shell(const char *cmd)
*/
static int
match_cfg_line(Options *options, char **condition, struct passwd *pw,
- const char *host_arg, const char *original_host, int post_canon,
- const char *filename, int linenum)
+ const char *host_arg, const char *original_host, int final_pass,
+ int *want_final_pass, const char *filename, int linenum)
{
char *arg, *oattrib, *attrib, *cmd, *cp = *condition, *host, *criteria;
const char *ruser;
@@ -554,7 +555,7 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
*/
port = options->port <= 0 ? default_ssh_port() : options->port;
ruser = options->user == NULL ? pw->pw_name : options->user;
- if (post_canon) {
+ if (final_pass) {
host = xstrdup(options->hostname);
} else if (options->hostname != NULL) {
/* NB. Please keep in sync with ssh.c:main() */
@@ -586,8 +587,16 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
goto out;
}
attributes++;
- if (strcasecmp(attrib, "canonical") == 0) {
- r = !!post_canon; /* force bitmask member to boolean */
+ if (strcasecmp(attrib, "canonical") == 0 ||
+ strcasecmp(attrib, "final") == 0) {
+ /*
+ * If the config requests "Match final" then remember
+ * this so we can perform a second pass later.
+ */
+ if (strcasecmp(attrib, "final") == 0 &&
+ want_final_pass != NULL)
+ *want_final_pass = 1;
+ r = !!final_pass; /* force bitmask member to boolean */
if (r == (negate ? 1 : 0))
this_result = result = 0;
debug3("%.200s line %d: %smatched '%s'",
@@ -824,14 +833,14 @@ process_config_line(Options *options, struct passwd *pw, const char *host,
int linenum, int *activep, int flags)
{
return process_config_line_depth(options, pw, host, original_host,
- line, filename, linenum, activep, flags, 0);
+ line, filename, linenum, activep, flags, NULL, 0);
}
#define WHITESPACE " \t\r\n"
static int
process_config_line_depth(Options *options, struct passwd *pw, const char *host,
const char *original_host, char *line, const char *filename,
- int linenum, int *activep, int flags, int depth)
+ int linenum, int *activep, int flags, int *want_final_pass, int depth)
{
char *s, **charptr, *endofnumber, *keyword, *arg, *arg2;
char **cpptr, fwdarg[256];
@@ -1339,7 +1348,8 @@ parse_keytypes:
fatal("Host directive not supported as a command-line "
"option");
value = match_cfg_line(options, &s, pw, host, original_host,
- flags & SSHCONF_POSTCANON, filename, linenum);
+ flags & SSHCONF_FINAL, want_final_pass,
+ filename, linenum);
if (value < 0)
fatal("%.200s line %d: Bad Match condition", filename,
linenum);
@@ -1548,7 +1558,7 @@ parse_keytypes:
pw, host, original_host, options,
flags | SSHCONF_CHECKPERM |
(oactive ? 0 : SSHCONF_NEVERMATCH),
- activep, depth + 1);
+ activep, want_final_pass, depth + 1);
if (r != 1 && errno != ENOENT) {
fatal("Can't open user config file "
"%.100s: %.100s", gl.gl_pathv[i],
@@ -1751,19 +1761,20 @@ parse_keytypes:
*/
int
read_config_file(const char *filename, struct passwd *pw, const char *host,
- const char *original_host, Options *options, int flags)
+ const char *original_host, Options *options, int flags,
+ int *want_final_pass)
{
int active = 1;
return read_config_file_depth(filename, pw, host, original_host,
- options, flags, &active, 0);
+ options, flags, &active, want_final_pass, 0);
}
#define READCONF_MAX_DEPTH 16
static int
read_config_file_depth(const char *filename, struct passwd *pw,
const char *host, const char *original_host, Options *options,
- int flags, int *activep, int depth)
+ int flags, int *activep, int *want_final_pass, int depth)
{
FILE *f;
char *line = NULL;
@@ -1798,7 +1809,8 @@ read_config_file_depth(const char *filename, struct passwd *pw,
/* Update line number counter. */
linenum++;
if (process_config_line_depth(options, pw, host, original_host,
- line, filename, linenum, activep, flags, depth) != 0)
+ line, filename, linenum, activep, flags, want_final_pass,
+ depth) != 0)
bad_options++;
}
free(line);
diff --git a/readconf.h b/readconf.h
index fc7e3825..8e36bf32 100644
--- a/readconf.h
+++ b/readconf.h
@@ -185,7 +185,7 @@ typedef struct {
#define SSHCONF_CHECKPERM 1 /* check permissions on config file */
#define SSHCONF_USERCONF 2 /* user provided config file not system */
-#define SSHCONF_POSTCANON 4 /* After hostname canonicalisation */
+#define SSHCONF_FINAL 4 /* Final pass over config, after canon. */
#define SSHCONF_NEVERMATCH 8 /* Match/Host never matches; internal only */
#define SSH_UPDATE_HOSTKEYS_NO 0
@@ -203,7 +203,7 @@ void fill_default_options_for_canonicalization(Options *);
int process_config_line(Options *, struct passwd *, const char *,
const char *, char *, const char *, int, int *, int);
int read_config_file(const char *, struct passwd *, const char *,
- const char *, Options *, int);
+ const char *, Options *, int, int *);
int parse_forward(struct Forward *, const char *, int, int);
int parse_jump(const char *, Options *, int);
int parse_ssh_uri(const char *, char **, char **, int *);
diff --git a/ssh-keysign.c b/ssh-keysign.c
index 8f487b8c..7ea5ad0e 100644
--- a/ssh-keysign.c
+++ b/ssh-keysign.c
@@ -208,7 +208,8 @@ main(int argc, char **argv)
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
- (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", "", &options, 0);
+ (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", "",
+ &options, 0, NULL);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
diff --git a/ssh.c b/ssh.c
index 1ac903d1..c6cb7847 100644
--- a/ssh.c
+++ b/ssh.c
@@ -527,7 +527,8 @@ check_load(int r, const char *path, const char *message)
* file if the user specifies a config file on the command line.
*/
static void
-process_config_files(const char *host_name, struct passwd *pw, int post_canon)
+process_config_files(const char *host_name, struct passwd *pw, int final_pass,
+ int *want_final_pass)
{
char buf[PATH_MAX];
int r;
@@ -535,7 +536,8 @@ process_config_files(const char *host_name, struct passwd *pw, int post_canon)
if (config != NULL) {
if (strcasecmp(config, "none") != 0 &&
!read_config_file(config, pw, host, host_name, &options,
- SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
+ SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
+ want_final_pass))
fatal("Can't open user config file %.100s: "
"%.100s", config, strerror(errno));
} else {
@@ -544,12 +546,12 @@ process_config_files(const char *host_name, struct passwd *pw, int post_canon)
if (r > 0 && (size_t)r < sizeof(buf))
(void)read_config_file(buf, pw, host, host_name,
&options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
- (post_canon ? SSHCONF_POSTCANON : 0));
+ (final_pass ? SSHCONF_FINAL : 0), want_final_pass);
/* Read systemwide configuration file after user config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
host, host_name, &options,
- post_canon ? SSHCONF_POSTCANON : 0);
+ final_pass ? SSHCONF_FINAL : 0, want_final_pass);
}
}
@@ -581,7 +583,7 @@ main(int ac, char **av)
{
struct ssh *ssh = NULL;
int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
- int was_addr, config_test = 0, opt_terminated = 0;
+ int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile;
char cname[NI_MAXHOST];
struct stat st;
@@ -1089,7 +1091,9 @@ main(int ac, char **av)
);
/* Parse the configuration files */
- process_config_files(host_arg, pw, 0);
+ process_config_files(host_arg, pw, 0, &want_final_pass);
+ if (want_final_pass)
+ debug("configuration requests final Match pass");
/* Hostname canonicalisation needs a few options filled. */
fill_default_options_for_canonicalization(&options);
@@ -1146,12 +1150,17 @@ main(int ac, char **av)
* If canonicalisation is enabled then re-parse the configuration
* files as new stanzas may match.
*/
- if (options.canonicalize_hostname != 0) {
- debug("Re-reading configuration after hostname "
- "canonicalisation");
+ if (options.canonicalize_hostname != 0 && !want_final_pass) {
+ debug("hostname canonicalisation enabled, "
+ "will re-parse configuration");
+ want_final_pass = 1;
+ }
+
+ if (want_final_pass) {
+ debug("re-parsing configuration");
free(options.hostname);
options.hostname = xstrdup(host);
- process_config_files(host_arg, pw, 1);
+ process_config_files(host_arg, pw, 1, NULL);
/*
* Address resolution happens early with canonicalisation
* enabled and the port number may have changed since, so
diff --git a/ssh_config.5 b/ssh_config.5
index 4d5b01d3..58a5fa1c 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -139,6 +139,7 @@ or the single token
which always matches.
The available criteria keywords are:
.Cm canonical ,
+.Cm final ,
.Cm exec ,
.Cm host ,
.Cm originalhost ,
@@ -148,12 +149,15 @@ and
The
.Cm all
criteria must appear alone or immediately after
-.Cm canonical .
+.Cm canonical
+or
+.Cm final .
Other criteria may be combined arbitrarily.
All criteria but
.Cm all
-and
.Cm canonical
+and
+.Cm final
require an argument.
Criteria may be negated by prepending an exclamation mark
.Pq Sq !\& .
@@ -166,6 +170,20 @@ after hostname canonicalization (see the
option.)
This may be useful to specify conditions that work with canonical host
names only.
+.Pp
+The
+.Cm final
+keyword requests that the configuration be re-parsed (regardless of whether
+.Cm CanonicalizeHostname
+is enabled), and matches only during this final pass.
+If
+.Cm CanonicalizeHostname
+is enabled, then
+.Cm canonical
+and
+.Cm final
+match during the same pass.
+.Pp
The
.Cm exec
keyword executes the specified command under the user's shell.