upstream: allow %n to be expanded in ProxyCommand strings

From Zachary Harmany via github.com/openssh/openssh-portable/pull/118
ok dtucker@

OpenBSD-Commit-ID: 7eebf1b7695f50c66d42053d352a4db9e8fb84b6

1 files changed, 20 insertions, 15 deletions

diff --git a/sshconnect.c b/sshconnect.c
index ed44fccb8..740780443 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.317 2019/06/28 13:35:04 deraadt Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.318 2019/09/13 04:27:35 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -87,14 +87,18 @@ static void warn_changed_key(struct sshkey *);
 /* Expand a proxy command */
 static char *
 expand_proxy_command(const char *proxy_command, const char *user,
-    const char *host, int port)
+    const char *host, const char *host_arg, int port)
 {
         char *tmp, *ret, strport[NI_MAXSERV];
 
         snprintf(strport, sizeof strport, "%d", port);
         xasprintf(&tmp, "exec %s", proxy_command);
-        ret = percent_expand(tmp, "h", host, "p", strport,
-            "r", options.user, (char *)NULL);
+        ret = percent_expand(tmp,
+            "h", host,
+            "n", host_arg,
+            "p", strport,
+            "r", options.user,
+            (char *)NULL);
         free(tmp);
         return ret;
 }
@@ -122,8 +126,8 @@ stderr_null(void)
  * a connected fd back to us.
  */
 static int
-ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host, u_short port,
-    const char *proxy_command)
+ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host,
+    const char *host_arg, u_short port, const char *proxy_command)
 {
         char *command_string;
         int sp[2], sock;
@@ -138,7 +142,7 @@ ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host, u_short port,
                     "proxy dialer: %.100s", strerror(errno));
 
         command_string = expand_proxy_command(proxy_command, options.user,
-            host, port);
+            host_arg, host, port);
         debug("Executing proxy dialer command: %.500s", command_string);
 
         /* Fork and execute the proxy command. */
@@ -204,8 +208,8 @@ ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host, u_short port,
  * Connect to the given ssh server using a proxy command.
  */
 static int
-ssh_proxy_connect(struct ssh *ssh, const char *host, u_short port,
-    const char *proxy_command)
+ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg,
+    u_short port, const char *proxy_command)
 {
         char *command_string;
         int pin[2], pout[2];
@@ -221,7 +225,7 @@ ssh_proxy_connect(struct ssh *ssh, const char *host, u_short port,
                     strerror(errno));
 
         command_string = expand_proxy_command(proxy_command, options.user,
-            host, port);
+            host_arg, host, port);
         debug("Executing proxy command: %.500s", command_string);
 
         /* Fork and execute the proxy command. */
@@ -543,9 +547,9 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
 }
 
 int
-ssh_connect(struct ssh *ssh, const char *host, struct addrinfo *addrs,
-    struct sockaddr_storage *hostaddr, u_short port, int family,
-    int connection_attempts, int *timeout_ms, int want_keepalive)
+ssh_connect(struct ssh *ssh, const char *host, const char *host_arg,
+    struct addrinfo *addrs, struct sockaddr_storage *hostaddr, u_short port,
+    int family, int connection_attempts, int *timeout_ms, int want_keepalive)
 {
         int in, out;
 
@@ -564,10 +568,11 @@ ssh_connect(struct ssh *ssh, const char *host, struct addrinfo *addrs,
                         return -1; /* ssh_packet_set_connection logs error */
                 return 0;
         } else if (options.proxy_use_fdpass) {
-                return ssh_proxy_fdpass_connect(ssh, host, port,
+                return ssh_proxy_fdpass_connect(ssh, host, host_arg, port,
                     options.proxy_command);
         }
-        return ssh_proxy_connect(ssh, host, port, options.proxy_command);
+        return ssh_proxy_connect(ssh, host, host_arg, port,
+            options.proxy_command);
 }
 
 /* defaults to 'no' */