wiretap: register most built-in file types from its module.

Remove most of the built-in file types from the table in
wiretap/file_access.c and, instead, have the file types register
themselves, using wtap_register_file_type_subtypes().

This reduces the source code changes needed to add a new file type from
three (add the handler, add the file type to the table in file_access.c,
add a #define for the file type in wiretap/wtap.h) to one (add the
handler).  (It also requires adding the handler's source file to
wiretap/CMakeLists.txt, but that's required in both cases.)

A few remain because the WTAP_FILE_TYPE_SUBTYPE_ #define is used
elsewhere; that needs to be fixed.

Fix the wiretap/CMakefile.txt file to scan k12text.l, as that now
contains a registration routine.  In the process, avoid scanning files
that don't implement a file type and won't ever have a registration
routine.

Add a Lua routine to fetch the total number of file types; we use that
in some code to construct the wtap_filetypes table, which we need to do
in order to continue to have all the values that used to come from the
WTAP_FILE_TYPE_SUBTYPE_ types.

While we're at it, add modelines to a file that lacked them.

1 files changed, 36 insertions, 1 deletions

diff --git a/wiretap/mime_file.c b/wiretap/mime_file.c
index 2096a299ef..171cd3706e 100644
--- a/wiretap/mime_file.c
+++ b/wiretap/mime_file.c
@@ -90,6 +90,10 @@ static const mime_files_t magic_files[] = {
 
 #define	N_MAGIC_TYPES	(sizeof(magic_files) / sizeof(magic_files[0]))
 
+static int mime_file_type_subtype = -1;
+
+void register_mime(void);
+
 wtap_open_return_val
 mime_file_open(wtap *wth, int *err, gchar **err_info)
 {
@@ -135,7 +139,7 @@ mime_file_open(wtap *wth, int *err, gchar **err_info)
 	if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
 		return WTAP_OPEN_ERROR;
 
-	wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_MIME;
+	wth->file_type_subtype = mime_file_type_subtype;
 	wth->file_encap = WTAP_ENCAP_MIME;
 	wth->file_tsprec = WTAP_TSPREC_SEC;
 	wth->subtype_read = wtap_full_file_read;
@@ -145,6 +149,37 @@ mime_file_open(wtap *wth, int *err, gchar **err_info)
 	return WTAP_OPEN_MINE;
 }
 
+static const struct file_type_subtype_info mime_info = {
+	"MIME File Format", "mime", NULL, NULL,
+	 FALSE, FALSE, 0,
+	 NULL, NULL, NULL
+};
+
+/*
+ * XXX - registered solely for the benefit of Lua scripts that
+ * look for the file type "JPEG_JFIF"; it may be removed once
+ * we get rid of wtap_filetypes.
+ */
+static const struct file_type_subtype_info jpeg_jfif_info = {
+	"JPEG/JFIF", "jpeg", "jpg", "jpeg;jfif",
+	FALSE, FALSE, 0,
+	NULL, NULL, NULL
+};
+
+void register_mime(void)
+{
+	mime_file_type_subtype =
+	    wtap_register_file_type_subtypes(&mime_info,
+	        WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
+
+	/*
+	 * Obsoleted by "mime", so just register it; we don't
+	 * need its return value.
+	 */
+	wtap_register_file_type_subtypes(&jpeg_jfif_info,
+	    WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *