GUAC-744: Generate and store connection ID within guac_client.

configure.ac

@@ -62,6 +62,10 @@ AC_CHECK_LIB([pthread], [pthread_create], [PTHREAD_LIBS=-lpthread
               AC_DEFINE([HAVE_LIBPTHREAD],,
                         [Whether libpthread was found])])
 
+# libossp-uuid 
+AC_CHECK_LIB([ossp-uuid], [uuid_create], [UUID_LIBS=-lossp-uuid],
+             AC_MSG_ERROR("The OSSP UUID library is required"))
+
 # cunit
 AC_CHECK_LIB([cunit], [CU_run_test], [CUNIT_LIBS=-lcunit])
 
@@ -73,6 +77,7 @@ AC_SUBST(MATH_LIBS)
 AC_SUBST(PNG_LIBS)
 AC_SUBST(CAIRO_LIBS)
 AC_SUBST(PTHREAD_LIBS)
+AC_SUBST(UUID_LIBS)
 AC_SUBST(CUNIT_LIBS)
 
 # Library functions

src/guacd/daemon.c

@@ -182,6 +182,12 @@ void guacd_handle_connection(guac_socket* socket) {
 
     /* Get client */
     client = guac_client_alloc();
+    if (client == NULL) {
+        guacd_log_guac_error("Client could not be allocated");
+        guac_socket_free(socket);
+        return;
+    }
+
     client->socket = socket;
     client->log_info_handler = guacd_client_log_info;
     client->log_error_handler = guacd_client_log_error;
@@ -230,6 +236,8 @@ void guacd_handle_connection(guac_socket* socket) {
         return;
     }
 
+    guacd_log_info("Connection ID is \"%s\"", client->connection_id);
+
     /* Start client threads */
     guacd_log_info("Starting client");
     if (guacd_client_start(client))

src/libguac/Makefile.am

@@ -88,6 +88,6 @@ noinst_HEADERS += ogg_encoder.h
 endif
 
 lib_LTLIBRARIES = libguac.la
-libguac_la_LDFLAGS = -version-info 7:0:0 @PTHREAD_LIBS@ @CAIRO_LIBS@ @PNG_LIBS@ @VORBIS_LIBS@
+libguac_la_LDFLAGS = -version-info 7:0:0 @PTHREAD_LIBS@ @CAIRO_LIBS@ @PNG_LIBS@ @VORBIS_LIBS@ @UUID_LIBS@
 libguac_la_LIBADD = @LIBADD_DLOPEN@ 
 

src/libguac/client.c

@@ -33,6 +33,8 @@
 #include "stream.h"
 #include "timestamp.h"
 
+#include <ossp/uuid.h>
+
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -115,6 +117,64 @@ void guac_client_free_stream(guac_client* client, guac_stream* stream) {
 
 }
 
+/**
+ * Returns a newly allocated string containing a guaranteed-unique connection
+ * identifier string which is 37 characters long and begins with a '$'
+ * character.  If an error occurs, NULL is returned, and no memory is
+ * allocated.
+ */
+static char* __guac_generate_connection_id() {
+
+    char* buffer;
+    char* identifier;
+    size_t identifier_length;
+
+    uuid_t* uuid;
+
+    /* Attempt to create UUID object */
+    if (uuid_create(&uuid) != UUID_RC_OK) {
+        guac_error = GUAC_STATUS_NO_MEMORY;
+        guac_error_message = "Could not allocate memory for UUID";
+        return NULL;
+    }
+
+    /* Generate random UUID */
+    if (uuid_make(uuid, UUID_MAKE_V4) != UUID_RC_OK) {
+        uuid_destroy(uuid);
+        guac_error = GUAC_STATUS_NO_MEMORY;
+        guac_error_message = "UUID generation failed";
+        return NULL;
+    }
+
+    /* Allocate buffer for future formatted ID */
+    buffer = malloc(UUID_LEN_STR + 2);
+    if (buffer == NULL) {
+        uuid_destroy(uuid);
+        guac_error = GUAC_STATUS_NO_MEMORY;
+        guac_error_message = "Could not allocate memory for connection ID";
+        return NULL;
+    }
+
+    identifier = &(buffer[1]);
+    identifier_length = UUID_LEN_STR + 1;
+
+    /* Build connection ID from UUID */
+    if (uuid_export(uuid, UUID_FMT_STR, &identifier, &identifier_length) != UUID_RC_OK) {
+        free(buffer);
+        uuid_destroy(uuid);
+        guac_error = GUAC_STATUS_BAD_STATE;
+        guac_error_message = "Conversion of UUID to connection ID failed";
+        return NULL;
+    }
+
+    uuid_destroy(uuid);
+
+    buffer[0] = '$';
+    buffer[UUID_LEN_STR + 1] = '\0';
+    return buffer;
+
+}
+
 guac_client* guac_client_alloc() {
 
     int i;
@@ -135,6 +195,13 @@ guac_client* guac_client_alloc() {
 
     client->state = GUAC_CLIENT_RUNNING;
 
+    /* Generate ID */
+    client->connection_id = __guac_generate_connection_id();
+    if (client->connection_id == NULL) {
+        free(client);
+        return NULL;
+    }
+
     /* Allocate buffer and layer pools */
     client->__buffer_pool = guac_pool_alloc(GUAC_BUFFER_POOL_INITIAL_SIZE);
     client->__layer_pool = guac_pool_alloc(GUAC_BUFFER_POOL_INITIAL_SIZE);

src/libguac/guacamole/client.h

@@ -419,6 +419,15 @@ struct guac_client {
      */
     guac_stream* __input_streams;
 
+    /**
+     * The unique identifier allocated for the connection, which may
+     * be used within the Guacamole protocol to refer to this connection.
+     * This identifier is guaranteed to be unique from all existing
+     * connections and will not collide with any available protocol
+     * names.
+     */
+    char* connection_id;
+
 };
 
 /**