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, 19 insertions, 3 deletions

diff --git a/wiretap/nettl.c b/wiretap/nettl.c
index 65d654cd5a..e698b5b3b7 100644
--- a/wiretap/nettl.c
+++ b/wiretap/nettl.c
@@ -173,6 +173,10 @@ static gboolean nettl_read_rec(wtap *wth, FILE_T fh, wtap_rec *rec,
 static gboolean nettl_dump(wtap_dumper *wdh, const wtap_rec *rec,
     const guint8 *pd, int *err, gchar **err_info);
 
+static int nettl_file_type_subtype = -1;
+
+void register_nettl(void);
+
 wtap_open_return_val nettl_open(wtap *wth, int *err, gchar **err_info)
 {
     struct nettl_file_hdr file_hdr;
@@ -200,7 +204,7 @@ wtap_open_return_val nettl_open(wtap *wth, int *err, gchar **err_info)
         return WTAP_OPEN_ERROR;
 
     /* This is an nettl file */
-    wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_NETTL;
+    wth->file_type_subtype = nettl_file_type_subtype;
     nettl = g_new(nettl_t,1);
     wth->priv = (void *)nettl;
     if (file_hdr.os_vers[2] == '1' && file_hdr.os_vers[3] == '1')
@@ -613,7 +617,7 @@ nettl_read_rec(wtap *wth, FILE_T fh, wtap_rec *rec, Buffer *buf,
    when they are first opened, so we allow that for tshark read/write.
  */
 
-int nettl_dump_can_write_encap(int encap)
+static int nettl_dump_can_write_encap(int encap)
 {
 
     switch (encap) {
@@ -642,7 +646,7 @@ int nettl_dump_can_write_encap(int encap)
 
 /* Returns TRUE on success, FALSE on failure;
    sets "*err" to an error code on failure */
-gboolean nettl_dump_open(wtap_dumper *wdh, int *err, gchar **err_info _U_)
+static gboolean nettl_dump_open(wtap_dumper *wdh, int *err, gchar **err_info _U_)
 {
     struct nettl_file_hdr file_hdr;
 
@@ -793,6 +797,18 @@ static gboolean nettl_dump(wtap_dumper *wdh,
     return TRUE;
 }
 
+static const struct file_type_subtype_info nettl_info = {
+    "HP-UX nettl trace", "nettl", "trc0", "trc1",
+    FALSE, FALSE, 0,
+    nettl_dump_can_write_encap, nettl_dump_open, NULL
+};
+
+void register_nettl(void)
+{
+    nettl_file_type_subtype = wtap_register_file_type_subtypes(&nettl_info,
+                                                               WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *