GUACAMOLE-565: Add terminal-type parameter for SSH and Telnet.

Add a terminal-type parameter for SSH and Telnet connections, to specify
the terminal emulator type that is passed to programs. If not specified,
the default type of "linux" is used in keep with existing behavior.

src/protocols/ssh/settings.c

@@ -57,6 +57,7 @@ const char* GUAC_SSH_CLIENT_ARGS[] = {
     "read-only",
     "server-alive-interval",
     "backspace",
+    "terminal-type",
     NULL
 };
 
@@ -217,6 +218,12 @@ enum SSH_ARGS_IDX {
      */
     IDX_BACKSPACE,
 
+    /**
+     * The terminal emulator type that is passed to the remote system (e.g.
+     * "xterm" or "xterm-256color"). "linux" is used if unspecified.
+     */
+    IDX_TERMINAL_TYPE,
+
     SSH_ARGS_COUNT
 };
 
@@ -361,6 +368,11 @@ guac_ssh_settings* guac_ssh_parse_args(guac_user* user,
         guac_user_parse_args_int(user, GUAC_SSH_CLIENT_ARGS, argv,
                 IDX_BACKSPACE, 127);
 
+    /* Read terminal emulator type. */
+    settings->terminal_type =
+        guac_user_parse_args_string(user, GUAC_SSH_CLIENT_ARGS, argv,
+                IDX_TERMINAL_TYPE, "linux");
+
     /* Parsing was successful */
     return settings;
 
@@ -396,6 +408,9 @@ void guac_ssh_settings_free(guac_ssh_settings* settings) {
     free(settings->recording_name);
     free(settings->recording_path);
 
+    /* Free terminal emulator type. */
+    free(settings->terminal_type);
+
     /* Free overall structure */
     free(settings);
 

src/protocols/ssh/settings.h

@@ -228,6 +228,11 @@ typedef struct guac_ssh_settings {
      */
     int backspace;
 
+    /**
+     * The terminal emulator type that is passed to the remote system.
+     */
+    char* terminal_type;
+
 } guac_ssh_settings;
 
 /**

src/protocols/ssh/ssh.c

@@ -307,7 +307,8 @@ void* ssh_client_thread(void* data) {
                 "  Backspace may not work as expected.");
 
     /* Request PTY */
-    if (libssh2_channel_request_pty_ex(ssh_client->term_channel, "linux", sizeof("linux")-1,
+    if (libssh2_channel_request_pty_ex(ssh_client->term_channel,
+            settings->terminal_type, strlen(settings->terminal_type),
             ssh_ttymodes, ttymodeBytes, ssh_client->term->term_width,
             ssh_client->term->term_height, 0, 0)) {
         guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to allocate PTY.");

src/protocols/telnet/settings.c

@@ -51,6 +51,7 @@ const char* GUAC_TELNET_CLIENT_ARGS[] = {
     "create-recording-path",
     "read-only",
     "backspace",
+    "terminal-type",
     NULL
 };
 
@@ -181,6 +182,12 @@ enum TELNET_ARGS_IDX {
      */
     IDX_BACKSPACE,
 
+    /**
+     * The terminal emulator type that is passed to the remote system (e.g.
+     * "xterm" or "xterm-256color"). "linux" is used if unspecified.
+     */
+    IDX_TERMINAL_TYPE,
+
     TELNET_ARGS_COUNT
 };
 
@@ -340,6 +347,11 @@ guac_telnet_settings* guac_telnet_parse_args(guac_user* user,
         guac_user_parse_args_int(user, GUAC_TELNET_CLIENT_ARGS, argv,
                 IDX_BACKSPACE, 127);
 
+    /* Read terminal emulator type. */
+    settings->terminal_type =
+        guac_user_parse_args_string(user, GUAC_TELNET_CLIENT_ARGS, argv,
+                IDX_TERMINAL_TYPE, "linux");
+
     /* Parsing was successful */
     return settings;
 
@@ -379,6 +391,9 @@ void guac_telnet_settings_free(guac_telnet_settings* settings) {
     free(settings->recording_name);
     free(settings->recording_path);
 
+    /* Free terminal emulator type. */
+    free(settings->terminal_type);
+
     /* Free overall structure */
     free(settings);
 

src/protocols/telnet/settings.h

@@ -214,6 +214,11 @@ typedef struct guac_telnet_settings {
      */
     int backspace;
 
+    /**
+     * The terminal emulator type that is passed to the remote system.
+     */
+    char* terminal_type;
+
 } guac_telnet_settings;
 
 /**

src/protocols/telnet/telnet.c

@@ -216,7 +216,7 @@ static void __guac_telnet_event_handler(telnet_t* telnet, telnet_event_t* event,
         /* Terminal type request */
         case TELNET_EV_TTYPE:
             if (event->ttype.cmd == TELNET_TTYPE_SEND)
-                telnet_ttype_is(telnet_client->telnet, "linux");
+                telnet_ttype_is(telnet_client->telnet, settings->terminal_type);
             break;
 
         /* Environment request */