Add command-line arg for input file format for tshark/wireshark

Now that we have the ability to choose input file format type
in the GUI, we might as well have it in the command-line too.
Plus it would help me in test-stuies if we had a commandline.
So I've added a '-X read_format:Foo' for this.  Using just
'-X read_format:', or with a bad name, will make it print out
the full list (in tshark); just like the '-F' does for output
file formats.

Note: I am *not* putting in code for Win32 GUI,
because I can't compile that and I wouldn't have even
done the GTK one if I could compile Qt originally. (I don't think we need
to add any more features to GTK or Win32, just Qt from now on,
right?)

Change-Id: I2fe6481d186f63bd2303b9e591edf397a2e14b64
Reviewed-on: https://code.wireshark.org/review/493
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

tshark.c

@@ -244,6 +244,28 @@ list_capture_types(void) {
   g_free(captypes);
 }
 
+static void
+list_read_capture_types(void) {
+  int                 i;
+  struct string_elem *captypes;
+  GSList             *list = NULL;
+  const char *magic = "Magic-value-based";
+  const char *heuristic = "Heuristics-based";
+
+  /* this is a hack, but WTAP_NUM_FILE_TYPES_SUBTYPES is always >= number of open routines so we're safe */
+  captypes = g_new(struct string_elem, WTAP_NUM_FILE_TYPES_SUBTYPES);
+
+  fprintf(stderr, "tshark: The available read file types for the \"-X read_format:\" option are:\n");
+  for (i = 0; open_routines[i].name != NULL; i++) {
+    captypes[i].sstr = open_routines[i].name;
+    captypes[i].lstr = (open_routines[i].type == OPEN_INFO_MAGIC) ? magic : heuristic;
+    list = g_slist_insert_sorted(list, &captypes[i], string_compare);
+  }
+  g_slist_foreach(list, string_elem_print, NULL);
+  g_slist_free(list);
+  g_free(captypes);
+}
+
 static void
 print_usage(gboolean print_ver)
 {
@@ -930,6 +952,7 @@ main(int argc, char *argv[])
   volatile int         out_file_type = WTAP_FILE_TYPE_SUBTYPE_PCAP;
 #endif
   volatile gboolean    out_file_name_res = FALSE;
+  volatile int         in_file_type = WTAP_TYPE_AUTO;
   gchar               *volatile cf_name = NULL;
   gchar               *rfilter = NULL;
   gchar               *dfilter = NULL;
@@ -1894,6 +1917,16 @@ main(int argc, char *argv[])
   }
 #endif
 
+  if (ex_opt_count("read_format") > 0) {
+    const gchar* name = ex_opt_get_next("read_format");
+    in_file_type = open_info_name_to_type(name);
+    if (in_file_type == WTAP_TYPE_AUTO) {
+      cmdarg_err("\"%s\" isn't a valid read file format type", name? name : "");
+      list_read_capture_types();
+      return 1;
+    }
+  }
+
   /* disabled protocols as per configuration file */
   if (gdp_path == NULL && dp_path == NULL) {
     set_disabled_protos_list();
@@ -1999,7 +2032,7 @@ main(int argc, char *argv[])
     relinquish_special_privs_perm();
     print_current_user();
 
-    if (cf_open(&cfile, cf_name, WTAP_TYPE_AUTO, FALSE, &err) != CF_OK) {
+    if (cf_open(&cfile, cf_name, in_file_type, FALSE, &err) != CF_OK) {
       epan_cleanup();
       return 2;
     }

ui/gtk/main.c

@@ -2149,6 +2149,7 @@ main(int argc, char *argv[])
     search_direction     jump_backwards = SD_FORWARD;
     dfilter_t           *jump_to_filter = NULL;
     int                  optind_initial;
+    unsigned int         in_file_type = WTAP_TYPE_AUTO;
 #ifdef HAVE_GTKOSXAPPLICATION
     GtkosxApplication   *theApp;
 #endif
@@ -3087,8 +3088,11 @@ main(int argc, char *argv[])
                 rfilter_parse_failed = TRUE;
             }
         }
+        if (ex_opt_count("read_format") > 0) {
+            in_file_type = open_info_name_to_type(ex_opt_get_next("read_format"));
+        }
         if (!rfilter_parse_failed) {
-            if (cf_open(&cfile, cf_name, WTAP_TYPE_AUTO, FALSE, &err) == CF_OK) {
+            if (cf_open(&cfile, cf_name, in_file_type, FALSE, &err) == CF_OK) {
                 /* "cf_open()" succeeded, so it closed the previous
                  capture file, and thus destroyed any previous read filter
                  attached to "cf". */

ui/qt/main.cpp

@@ -481,6 +481,8 @@ int main(int argc, char *argv[])
 
     QString locale;
     QString *cf_name = NULL;
+    QString *display_filter = NULL;
+    unsigned int in_file_type = WTAP_TYPE_AUTO;
 
     // In Qt 5, C strings are treated always as UTF-8 when converted to
     // QStrings; in Qt 4, the codec must be set to make that happen
@@ -497,8 +499,8 @@ int main(int argc, char *argv[])
     main_w->show();
     // We may not need a queued connection here but it would seem to make sense
     // to force the issue.
-    main_w->connect(&ws_app, SIGNAL(openCaptureFile(QString&)),
-            main_w, SLOT(openCaptureFile(QString&)));
+    main_w->connect(&ws_app, SIGNAL(openCaptureFile(QString&,QString&,unsigned int)),
+            main_w, SLOT(openCaptureFile(QString&,QString&,unsigned int)));
 
     // XXX Should the remaining code be in WiresharkApplcation::WiresharkApplication?
 #ifdef HAVE_LIBPCAP
@@ -872,6 +874,10 @@ int main(int argc, char *argv[])
 
     register_all_tap_listeners();
 
+    if (ex_opt_count("read_format") > 0) {
+        in_file_type = open_info_name_to_type(ex_opt_get_next("read_format"));
+    }
+
     splash_update(RA_PREFERENCES, NULL, NULL);
     prefs_p = ws_app.readConfigurationFiles (&gdp_path, &dp_path);
 
@@ -990,8 +996,13 @@ int main(int argc, char *argv[])
     wsApp->allSystemsGo();
     g_log(LOG_DOMAIN_MAIN, G_LOG_LEVEL_INFO, "Wireshark is up and ready to go");
 
-    if (cf_name != NULL) {
-        main_w->openCaptureFile(*cf_name);
+    /* user could specify filename, or display filter, or both */
+    if (cf_name != NULL || display_filter != NULL) {
+        if (display_filter == NULL)
+            display_filter = new QString();
+        if (cf_name == NULL)
+            cf_name = new QString();
+        main_w->openCaptureFile(*cf_name, *display_filter, in_file_type);
     }
 
     g_main_loop_new(NULL, FALSE);

ui/qt/main_window.h

@@ -164,7 +164,7 @@ signals:
 
 public slots:
     // in main_window_slots.cpp
-    void openCaptureFile(QString& cf_path = *new QString(), QString &display_filter = *new QString());
+    void openCaptureFile(QString& cf_path = *new QString(), QString &display_filter = *new QString(), const unsigned int type = WTAP_TYPE_AUTO);
     void filterPackets(QString& new_filter = *new QString(), bool force = false);
     void updateForUnsavedChanges();
     void layoutPanes();

ui/qt/main_window_slots.cpp

@@ -95,12 +95,11 @@
 
 const char *dfe_property_ = "display filter expression"; //TODO : Fix Translate
 
-void MainWindow::openCaptureFile(QString &cf_path, QString &display_filter)
+void MainWindow::openCaptureFile(QString &cf_path, QString &display_filter, unsigned int type)
 {
     QString file_name = "";
     dfilter_t *rfcode = NULL;
     int err;
-    unsigned int type = WTAP_TYPE_AUTO;
 
     testCaptureFileClose(false);
 

wiretap/file_access.c

@@ -412,6 +412,27 @@ void wtap_register_open_info(const struct open_info *oi) {
 #define S_ISDIR(mode)   (((mode) & S_IFMT) == S_IFDIR)
 #endif
 
+/* returns the 'type' number to use for wtap_open_offline based on the
+   passed-in name (the name in the open_info struct). It returns WTAP_TYPE_AUTO
+   on failure, which is the number 0. The 'type' number is the entry's index+1,
+   because that's what wtap_open_offline() expects it to be. */
+unsigned int open_info_name_to_type(const char *name)
+{
+	unsigned int i;
+    init_open_routines();
+
+	if (!name)
+		return WTAP_TYPE_AUTO;
+
+	for (i = 0; i < open_info_arr->len - 1; i++) {
+		if (open_routines[i].name != NULL &&
+			strcmp(name, open_routines[i].name) == 0)
+			return i+1;
+	}
+
+	return WTAP_TYPE_AUTO; /* no such file type */
+}
+
 static char *get_file_extension(const char *pathname)
 {
 	gchar *filename;

wiretap/wtap.h

@@ -1493,6 +1493,8 @@ void wtap_register_heuristic_open_info(const struct heuristic_open_info *oi);
 WS_DLL_PUBLIC
 void wtap_register_open_info(const struct open_info *oi);
 WS_DLL_PUBLIC
+unsigned int open_info_name_to_type(const char *name);
+WS_DLL_PUBLIC
 int wtap_register_file_type_subtypes(const struct file_type_subtype_info* fi);
 WS_DLL_PUBLIC
 int wtap_register_encap_type(const char* name, const char* short_name);