Add stub ack handler. Call SFTP functions when download code received.

src/protocols/ssh/sftp.c

@@ -167,7 +167,14 @@ int guac_sftp_end_handler(guac_client* client, guac_stream* stream) {
 
 }
 
-guac_stream* guac_sftp_download_file(guac_client* client, const char* filename) {
+int guac_sftp_ack_handler(guac_client* client, guac_stream* stream,
+        char* message, guac_protocol_status status) {
+    return 0;
+}
+
+guac_stream* guac_sftp_download_file(guac_client* client,
+        const char* filename) {
+
     /* STUB */
     return NULL;
 }

src/protocols/ssh/sftp.h

@@ -58,6 +58,12 @@ int guac_sftp_blob_handler(guac_client* client, guac_stream* stream,
  */
 int guac_sftp_end_handler(guac_client* client, guac_stream* stream);
 
+/**
+ * Handler for ack messages which continues an SFTP download.
+ */
+int guac_sftp_ack_handler(guac_client* client, guac_stream* stream,
+        char* message, guac_protocol_status status);
+
 /**
  * Begins (and automatically continues) an SFTP file download to the user.
  */

src/protocols/ssh/ssh_client.c

@@ -248,6 +248,7 @@ void* ssh_client_thread(void* data) {
         }
 
         /* Set file handlers */
+        client->ack_handler  = guac_sftp_ack_handler;
         client->file_handler = guac_sftp_file_handler;
         client->blob_handler = guac_sftp_blob_handler;
         client->end_handler  = guac_sftp_end_handler;

src/protocols/ssh/terminal_handlers.c

@@ -38,6 +38,7 @@
 #include <stdlib.h>
 
 #include "common.h"
+#include "sftp.h"
 #include "terminal.h"
 #include "terminal_handlers.h"
 #include "char_mappings.h"
@@ -920,7 +921,7 @@ int guac_terminal_guac_download(guac_terminal* term, char c) {
     if (c == 0x9C || c == 0x5C || c == 0x07) {
         filename[length++] = '\0';
         term->char_handler = guac_terminal_echo;
-        guac_client_log_info(term->client, "STUB: get: %s", filename);
+        guac_sftp_download_file(term->client, filename);
         length = 0;
     }