GUACAMOLE-269: Changes to initializing opcode array.

src/protocols/ssh/ssh.c

@@ -192,7 +192,6 @@ void* ssh_client_thread(void* data) {
         return NULL;
     }
 
-    /* Initialize a ttymode array */
     const int num_tty_opcodes = 1;
     char ssh_ttymodes[(GUAC_SSH_TTY_OPCODE_SIZE * num_tty_opcodes) + 1];
 
@@ -302,13 +301,15 @@ void* ssh_client_thread(void* data) {
     }
 
     /* Set up the ttymode array prior to requesting the PTY */
-    if (guac_ssh_ttymodes_init(ssh_ttymodes, sizeof(ssh_ttymodes),
-            num_tty_opcodes, (guac_ssh_ttymode){ GUAC_SSH_TTY_OP_VERASE, settings->backspace}))
-        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error configuring TTY mode encoding.");
+    int ttymodeBytes = guac_ssh_ttymodes_init(ssh_ttymodes, sizeof(ssh_ttymodes),
+            GUAC_SSH_TTY_OP_VERASE, settings->backspace, GUAC_SSH_TTY_OP_END);
+    if (ttymodeBytes < 1)
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error storing TTY mode encoding \
+                opcodes and values in array.");
 
     /* Request PTY */
     if (libssh2_channel_request_pty_ex(ssh_client->term_channel, "linux", sizeof("linux")-1,
-            ssh_ttymodes, sizeof(ssh_ttymodes), ssh_client->term->term_width,
+            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.");
         return NULL;

src/protocols/ssh/ttymode.c

@@ -21,38 +21,49 @@
 #include "ttymode.h"
 
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
 int guac_ssh_ttymodes_init(char opcode_array[], const int array_size,
-        const int num_opcodes, ...) {
+        ...) {
 
     /* Initialize the variable argument list. */
     va_list args;
-    va_start(args, num_opcodes);
-
-    /* Check to make sure the array has enough space.
-       We need one extra byte at the end for the ending opcode. */
-    if ((num_opcodes * GUAC_SSH_TTY_OPCODE_SIZE) >= (array_size))
-        return 1;
+    va_start(args, array_size);
 
+    /* Initialize array pointer and byte counter. */
     char *current = opcode_array;
-    for (int i = 0; i < num_opcodes; i++) {
+    int bytes = 0;
 
-        /* Get the next argument to this function */
-        guac_ssh_ttymode* ttymode = va_arg(args, guac_ssh_ttymode*);
+    /* Loop through variable argument list. */
+    while (true) {
+       
+        /* Check to make sure we don't overrun array. */ 
+        if (bytes >= array_size)
+            return -1;
 
-        /* Place opcode and value in array */
-        *(current++) = ttymode->opcode;
-        *(current++) = (ttymode->value >> 24) & 0xFF;
-        *(current++) = (ttymode->value >> 16) & 0xFF;
-        *(current++) = (ttymode->value >> 8) & 0xFF;
-        *(current++) = ttymode->value & 0xFF;
+        /* Next argument should be an opcode. */
+        char opcode = (char)va_arg(args, int);
+        *(current++) = opcode;
+        bytes += sizeof(char);
+
+        /* If it's the end opcode, we're done. */
+        if (opcode == GUAC_SSH_TTY_OP_END)
+            break;
+
+        /* Next argument should be 4-byte value. */
+        uint32_t value = va_arg(args, uint32_t);
+        *(current++) = (value >> 24) & 0xFF;
+        *(current++) = (value >> 16) & 0xFF;
+        *(current++) = (value >> 8) & 0xFF;
+        *(current++) = value & 0xFF;
+        bytes += sizeof(uint32_t);
     }
 
-    /* Put the end opcode in the last opcode space */
-    *(current) = GUAC_SSH_TTY_OP_END;
+    /* We're done processing arguments. */
+    va_end(args);
 
-    return 0;
+    return bytes;
 
 }

src/protocols/ssh/ttymode.h

@@ -76,9 +76,9 @@ typedef struct guac_ssh_ttymode {
  * in a single array, beginning with the opcode and followed
  * by a four byte value, repeating until the end opcode is
  * encountered.  This function takes the array, the array
- * size, expected number of opcodes, and that number of
- * guac_ssh_ttymode arguments and puts them in the array
- * exepcted by the SSH connection.
+ * size, and a variable number of opcode and value pair
+ * arguments and puts them in the array expected by the
+ * SSH connection.
  *
  * @param opcode_array
  *     Pointer to the opcode array that will ultimately
@@ -87,18 +87,15 @@ typedef struct guac_ssh_ttymode {
  * @param array_size
  *     Size, in bytes, of the array.
  *
- * @param num_opcodes
- *     Number of opcodes to expect.
- *
  * @params ...
- *     A variable number of guac_ssh_ttymodes
+ *     A variable number of opcode and value pairs
  *     to place in the array.
  *
  * @return
- *     Zero of the function is successful, non-zero
+ *     Number of bytes written to the array, or zero
  *     if a failure occurs.
  */
 int guac_ssh_ttymodes_init(char opcode_array[], const int array_size,
-        const int num_opcodes, ...);
+        ...);
 
 #endif