From e8b98abfc46b6413a6449fcb713f116ff1f82cf5 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mike.jumper@guac-dev.org>
Date: Mon, 19 Oct 2015 15:58:44 -0700
Subject: [PATCH] GUAC-1038: Add support for running specific commands via SSH
 (instead of a shell).

---
 src/protocols/ssh/client.c        | 11 +++++++++++
 src/protocols/ssh/client.h        |  6 ++++++
 src/protocols/ssh/guac_handlers.c |  3 +++
 src/protocols/ssh/ssh_client.c    | 16 +++++++++++++---
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/protocols/ssh/client.c b/src/protocols/ssh/client.c
index 3183e22e..f294363d 100644
--- a/src/protocols/ssh/client.c
+++ b/src/protocols/ssh/client.c
@@ -57,6 +57,7 @@ const char* GUAC_CLIENT_ARGS[] = {
     "enable-agent",
 #endif
     "color-scheme",
+    "command",
     NULL
 };
 
@@ -122,6 +123,12 @@ enum __SSH_ARGS_IDX {
      */
     IDX_COLOR_SCHEME,
 
+    /**
+     * The command to run instead if the default shell. If omitted, a normal
+     * shell session will be created.
+     */
+    IDX_COMMAND,
+
     SSH_ARGS_COUNT
 };
 
@@ -178,6 +185,10 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
     else
         strcpy(client_data->port, GUAC_SSH_DEFAULT_PORT);
 
+    /* Read command, if any */
+    if (argv[IDX_COMMAND][0] != 0)
+        client_data->command = strdup(argv[IDX_COMMAND]);
+
     /* Create terminal */
     client_data->term = guac_terminal_create(client,
             client_data->font_name, client_data->font_size,
diff --git a/src/protocols/ssh/client.h b/src/protocols/ssh/client.h
index 364fca2f..32e297c4 100644
--- a/src/protocols/ssh/client.h
+++ b/src/protocols/ssh/client.h
@@ -78,6 +78,12 @@ typedef struct ssh_guac_client_data {
      */
     char key_passphrase[1024];
 
+    /**
+     * The command to run instead of the default shell. If a normal shell
+     * session is desired, this will be NULL.
+     */
+    char* command;
+
     /**
      * The name of the font to use for display rendering.
      */
diff --git a/src/protocols/ssh/guac_handlers.c b/src/protocols/ssh/guac_handlers.c
index e18c5d5d..3b1ce2ce 100644
--- a/src/protocols/ssh/guac_handlers.c
+++ b/src/protocols/ssh/guac_handlers.c
@@ -116,6 +116,9 @@ int ssh_guac_client_free_handler(guac_client* client) {
     if (guac_client_data->user != NULL)
         guac_common_ssh_destroy_user(guac_client_data->user);
 
+    /* Free copied settings */
+    free(guac_client_data->command);
+
     /* Free generic data struct */
     free(client->data);
 
diff --git a/src/protocols/ssh/ssh_client.c b/src/protocols/ssh/ssh_client.c
index 6c089252..ffab21ac 100644
--- a/src/protocols/ssh/ssh_client.c
+++ b/src/protocols/ssh/ssh_client.c
@@ -264,9 +264,19 @@ void* ssh_client_thread(void* data) {
         return NULL;
     }
 
-    /* Request shell */
-    if (libssh2_channel_shell(client_data->term_channel)) {
-        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to associate shell with PTY.");
+    /* If a command is specified, run that instead of a shell */
+    if (client_data->command != NULL) {
+        if (libssh2_channel_exec(client_data->term_channel, client_data->command)) {
+            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                    "Unable to execute command.");
+            return NULL;
+        }
+    }
+
+    /* Otherwise, request a shell */
+    else if (libssh2_channel_shell(client_data->term_channel)) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                "Unable to associate shell with PTY.");
         return NULL;
     }