GUACAMOLE-1931: Allow writing to existing recording files.

src/libguac/guacamole/recording.h

@@ -148,6 +148,10 @@ typedef struct guac_recording {
  *     caution. Key events can easily contain sensitive information, such as
  *     passwords, credit card numbers, etc.
  *
+ * @param allow_write_existing
+ *     Non-zero if writing to an existing file should be allowed, or zero
+ *     otherwise.
+ *
  * @return
  *     A new guac_recording structure representing the in-progress
  *     recording if the recording file has been successfully created and a
@@ -156,7 +160,7 @@ typedef struct guac_recording {
 guac_recording* guac_recording_create(guac_client* client,
         const char* path, const char* name, int create_path,
         int include_output, int include_mouse, int include_touch,
-        int include_keys);
+        int include_keys, int allow_write_existing);
 
 /**
  * Frees the resources associated with the given in-progress recording. Note

src/libguac/recording.c

@@ -39,11 +39,13 @@
 
 /**
  * Attempts to open a new recording within the given path and having the given
- * name. If such a file already exists, sequential numeric suffixes (.1, .2,
- * .3, etc.) are appended until a filename is found which does not exist (or
- * until the maximum number of numeric suffixes has been tried). If the file
- * absolutely cannot be opened due to an error, -1 is returned and errno is set
- * appropriately.
+ * name. If opening the file fails for any reason, or if such a file already
+ * exists and allow_write_existing is not set, sequential numeric suffixes
+ * (.1, .2, .3, etc.) are appended until a filename is found which does not
+ * exist (or until the maximum number of numeric suffixes has been tried).
+ * If the file exists and allow_write_existing is set, the recording will be
+ * appended to any existing file contents. If the file absolutely cannot be
+ * opened due to an error, -1 is returned and errno is set appropriately.
  *
  * @param path
  *     The full path to the directory in which the data file should be created.
@@ -60,12 +62,17 @@
  * @param basename_size
  *     The number of bytes available within the provided basename buffer.
  *
+ * @param allow_write_existing
+ *     Non-zero if writing to an existing file should be allowed, or zero
+ *     otherwise.
+ *
  * @return
  *     The file descriptor of the open data file if open succeeded, or -1 on
  *     failure.
  */
 static int guac_recording_open(const char* path,
-        const char* name, char* basename, int basename_size) {
+        const char* name, char* basename, int basename_size,
+        int allow_write_existing) {
 
     int i;
 
@@ -81,10 +88,11 @@ static int guac_recording_open(const char* path,
         return -1;
     }
 
+    /* Require the file not exist already if allow_write_existing not set */
+    int flags = O_CREAT | O_WRONLY | (allow_write_existing ? 0 : O_EXCL);
+
     /* Attempt to open recording */
-    int fd = open(basename,
-            O_CREAT | O_EXCL | O_WRONLY,
-            S_IRUSR | S_IWUSR | S_IRGRP);
+    int fd = open(basename, flags, S_IRUSR | S_IWUSR | S_IRGRP);
 
     /* Continuously retry with alternate names on failure */
     if (fd == -1) {
@@ -101,9 +109,7 @@ static int guac_recording_open(const char* path,
             sprintf(suffix, "%i", i);
 
             /* Retry with newly-suffixed filename */
-            fd = open(basename,
-                    O_CREAT | O_EXCL | O_WRONLY,
-                    S_IRUSR | S_IWUSR | S_IRGRP);
+            fd = open(basename, flags, S_IRUSR | S_IWUSR | S_IRGRP);
 
         }
 
@@ -138,7 +144,7 @@ static int guac_recording_open(const char* path,
 guac_recording* guac_recording_create(guac_client* client,
         const char* path, const char* name, int create_path,
         int include_output, int include_mouse, int include_touch,
-        int include_keys) {
+        int include_keys, int allow_write_existing) {
 
     char filename[GUAC_COMMON_RECORDING_MAX_NAME_LENGTH];
 
@@ -155,7 +161,8 @@ guac_recording* guac_recording_create(guac_client* client,
     }
 
     /* Attempt to open recording file */
-    int fd = guac_recording_open(path, name, filename, sizeof(filename));
+    int fd = guac_recording_open(
+            path, name, filename, sizeof(filename), allow_write_existing);
     if (fd == -1) {
         guac_client_log(client, GUAC_LOG_ERROR,
                 "Creation of recording failed: %s", strerror(errno));

src/protocols/kubernetes/kubernetes.c

@@ -237,7 +237,8 @@ void* guac_kubernetes_client_thread(void* data) {
                 !settings->recording_exclude_output,
                 !settings->recording_exclude_mouse,
                 0, /* Touch events not supported */
-                settings->recording_include_keys);
+                settings->recording_include_keys,
+                settings->recording_write_existing);
     }
 
     /* Create terminal options with required parameters */

src/protocols/kubernetes/settings.c

@@ -51,6 +51,7 @@ const char* GUAC_KUBERNETES_CLIENT_ARGS[] = {
     "recording-exclude-mouse",
     "recording-include-keys",
     "create-recording-path",
+    "recording-write-existing",
     "read-only",
     "backspace",
     "scrollback",
@@ -210,6 +211,12 @@ enum KUBERNETES_ARGS_IDX {
      */
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    IDX_RECORDING_WRITE_EXISTING,
+
     /**
      * "true" if this connection should be read-only (user input should be
      * dropped), "false" or blank otherwise.
@@ -389,6 +396,11 @@ guac_kubernetes_settings* guac_kubernetes_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, false);
 
+    /* Parse allow write existing file flag */
+    settings->recording_write_existing =
+        guac_user_parse_args_boolean(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,
+                IDX_RECORDING_WRITE_EXISTING, false);
+
     /* Parse backspace key code */
     settings->backspace =
         guac_user_parse_args_int(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,

src/protocols/kubernetes/settings.h

@@ -234,6 +234,12 @@ typedef struct guac_kubernetes_settings {
      */
     bool recording_include_keys;
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    bool recording_write_existing;
+
     /**
      * The ASCII code, as an integer, that the Kubernetes client will use when
      * the backspace key is pressed. By default, this is 127, ASCII delete, if

src/protocols/rdp/rdp.c

@@ -841,7 +841,8 @@ void* guac_rdp_client_thread(void* data) {
                 !settings->recording_exclude_output,
                 !settings->recording_exclude_mouse,
                 !settings->recording_exclude_touch,
-                settings->recording_include_keys);
+                settings->recording_include_keys,
+                settings->recording_write_existing);
     }
 
     /* Continue handling connections until error or client disconnect */

src/protocols/rdp/settings.c

@@ -122,6 +122,7 @@ const char* GUAC_RDP_CLIENT_ARGS[] = {
     "recording-exclude-touch",
     "recording-include-keys",
     "create-recording-path",
+    "recording-write-existing",
     "resize-method",
     "enable-audio-input",
     "enable-touch",
@@ -564,6 +565,12 @@ enum RDP_ARGS_IDX {
      */
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    IDX_RECORDING_WRITE_EXISTING,
+
     /**
      * The method to use to apply screen size changes requested by the user.
      * Valid values are blank, "display-update", and "reconnect".
@@ -1161,6 +1168,11 @@ guac_rdp_settings* guac_rdp_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, 0);
 
+    /* Parse allow write existing file flag */
+    settings->recording_write_existing =
+        guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
+                IDX_RECORDING_WRITE_EXISTING, 0);
+
     /* No resize method */
     if (strcmp(argv[IDX_RESIZE_METHOD], "") == 0) {
         guac_user_log(user, GUAC_LOG_INFO, "Resize method: none");

src/protocols/rdp/settings.h

@@ -560,6 +560,12 @@ typedef struct guac_rdp_settings {
     int recording_include_keys;
 
     /**
+     * Non-zero if existing files should be appended to when creating a new 
+     * recording. Disabled by default.
+     */
+    int recording_write_existing;
+
+    /** 
      * The method to apply when the user's display changes size.
      */
     guac_rdp_resize_method resize_method;

src/protocols/ssh/settings.c

@@ -63,6 +63,7 @@ const char* GUAC_SSH_CLIENT_ARGS[] = {
     "recording-exclude-mouse",
     "recording-include-keys",
     "create-recording-path",
+    "recording-write-existing",
     "read-only",
     "server-alive-interval",
     "backspace",
@@ -241,6 +242,12 @@ enum SSH_ARGS_IDX {
      */
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    IDX_RECORDING_WRITE_EXISTING,
+
     /**
      * "true" if this connection should be read-only (user input should be
      * dropped), "false" or blank otherwise.
@@ -495,6 +502,11 @@ guac_ssh_settings* guac_ssh_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_SSH_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, false);
 
+    /* Parse allow write existing file flag */
+    settings->recording_write_existing =
+        guac_user_parse_args_boolean(user, GUAC_SSH_CLIENT_ARGS, argv,
+                IDX_RECORDING_WRITE_EXISTING, false);
+
     /* Parse server alive interval */
     settings->server_alive_interval =
         guac_user_parse_args_int(user, GUAC_SSH_CLIENT_ARGS, argv,

src/protocols/ssh/settings.h

@@ -251,6 +251,12 @@ typedef struct guac_ssh_settings {
      */
     bool recording_include_keys;
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    bool recording_write_existing;
+
     /**
      * The number of seconds between sending server alive messages.
      */

src/protocols/ssh/ssh.c

@@ -264,7 +264,8 @@ void* ssh_client_thread(void* data) {
                 !settings->recording_exclude_output,
                 !settings->recording_exclude_mouse,
                 0, /* Touch events not supported */
-                settings->recording_include_keys);
+                settings->recording_include_keys,
+                settings->recording_write_existing);
     }
 
     /* Create terminal options with required parameters */

src/protocols/telnet/settings.c

@@ -55,6 +55,7 @@ const char* GUAC_TELNET_CLIENT_ARGS[] = {
     "recording-exclude-mouse",
     "recording-include-keys",
     "create-recording-path",
+    "recording-write-existing",
     "read-only",
     "backspace",
     "terminal-type",
@@ -193,6 +194,12 @@ enum TELNET_ARGS_IDX {
      */
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    IDX_RECORDING_WRITE_EXISTING,
+
     /**
      * "true" if this connection should be read-only (user input should be
      * dropped), "false" or blank otherwise.
@@ -486,6 +493,11 @@ guac_telnet_settings* guac_telnet_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_TELNET_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, false);
 
+    /* Parse allow write existing file flag */
+    settings->recording_write_existing =
+        guac_user_parse_args_boolean(user, GUAC_TELNET_CLIENT_ARGS, argv,
+                IDX_RECORDING_WRITE_EXISTING, false);
+
     /* Parse backspace key code */
     settings->backspace =
         guac_user_parse_args_int(user, GUAC_TELNET_CLIENT_ARGS, argv,

src/protocols/telnet/settings.h

@@ -239,6 +239,12 @@ typedef struct guac_telnet_settings {
      */
     bool recording_include_keys;
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    bool recording_write_existing;
+
     /**
      * The ASCII code, as an integer, that the telnet client will use when the
      * backspace key is pressed.  By default, this is 127, ASCII delete, if

src/protocols/telnet/telnet.c

@@ -606,7 +606,8 @@ void* guac_telnet_client_thread(void* data) {
                 !settings->recording_exclude_output,
                 !settings->recording_exclude_mouse,
                 0, /* Touch events not supported */
-                settings->recording_include_keys);
+                settings->recording_include_keys,
+                settings->recording_write_existing);
     }
 
     /* Create terminal options with required parameters */

src/protocols/vnc/settings.c

@@ -84,6 +84,7 @@ const char* GUAC_VNC_CLIENT_ARGS[] = {
     "recording-exclude-mouse",
     "recording-include-keys",
     "create-recording-path",
+    "recording-write-existing",
     "disable-copy",
     "disable-paste",
 
@@ -331,6 +332,12 @@ enum VNC_ARGS_IDX {
      */
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    IDX_RECORDING_WRITE_EXISTING,
+
     /**
      * Whether outbound clipboard access should be blocked. If set to "true",
      * it will not be possible to copy data from the remote desktop to the
@@ -594,6 +601,11 @@ guac_vnc_settings* guac_vnc_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_VNC_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, false);
 
+    /* Parse allow write existing file flag */
+    settings->recording_write_existing =
+        guac_user_parse_args_boolean(user, GUAC_VNC_CLIENT_ARGS, argv,
+                IDX_RECORDING_WRITE_EXISTING, false);
+
     /* Parse clipboard copy disable flag */
     settings->disable_copy =
         guac_user_parse_args_boolean(user, GUAC_VNC_CLIENT_ARGS, argv,

src/protocols/vnc/settings.h

@@ -274,6 +274,12 @@ typedef struct guac_vnc_settings {
      * as passwords, credit card numbers, etc.
      */
     bool recording_include_keys;
+
+    /**
+     * Whether existing files should be appended to when creating a new recording.
+     * Disabled by default.
+     */
+    bool recording_write_existing;
 
     /**
      * Whether or not to send the magic Wake-on-LAN (WoL) packet prior to

src/protocols/vnc/vnc.c

@@ -428,7 +428,8 @@ void* guac_vnc_client_thread(void* data) {
                 !settings->recording_exclude_output,
                 !settings->recording_exclude_mouse,
                 0, /* Touch events not supported */
-                settings->recording_include_keys);
+                settings->recording_include_keys,
+                settings->recording_write_existing);
     }
 
     /* Create display */