osmocom
/
wireshark
11
0
Fork 1
Code Issues Pull Requests Projects Releases Wiki Activity

Lua: Make FileHandler seek_read() optional 

When FileHandler seek_read() is not implemented use a default
implementation which does the same as the provided example to
file_seek() and then call the FileHandler read().
This commit is contained in:
Stig Bjørlykke 2021-10-01 13:05:45 +02:00
parent c6b046abd7
commit 41f4855443
1 changed files with 62 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
epan/wslua/wslua_file_handler.c
View File

@ -15,6 +15,7 @@
#include "config.h"
#include "wslua_file_common.h"
#include <wiretap/file_wrappers.h>
/* WSLUA_CONTINUE_MODULE File */
@ -133,9 +134,8 @@ static gboolean
wslua_filehandler_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *offset);
static gboolean
wslua_filehandler_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info);
wslua_filehandler_seek_read(wtap *wth, gint64 seek_off, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info);
static void
wslua_filehandler_close(wtap *wth);
static void
@ -193,13 +193,8 @@ wslua_filehandler_open(wtap *wth, int *err, gchar **err_info)
return WTAP_OPEN_NOT_MINE;
}
if (fh->seek_read_ref != LUA_NOREF) {
wth->subtype_seek_read = wslua_filehandler_seek_read;
}
else {
ws_warning("Lua file format module lacks a seek-read routine");
return WTAP_OPEN_NOT_MINE;
}
/* when not having a seek_read routine a default will be used */
wth->subtype_seek_read = wslua_filehandler_seek_read;
/* it's ok to not have a close routine */
if (fh->read_close_ref != LUA_NOREF)
@ -238,15 +233,9 @@ wslua_filehandler_open(wtap *wth, int *err, gchar **err_info)
return retval;
}
/* The classic wtap read routine. This returns TRUE if it found the next packet,
* else FALSE.
* If it finds a frame/packet, it should set the pseudo-header info (ie, let Lua set it).
* Also Lua needs to set data_offset to the beginning of the line we're returning.
* This will be the seek_off parameter when this frame is re-read.
*/
static gboolean
wslua_filehandler_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *offset)
wslua_filehandler_read_packet(wtap *wth, FILE_T wth_fh, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *offset)
{
FileHandler fh = (FileHandler)(wth->wslua_data);
int retval = -1;
@ -265,7 +254,7 @@ wslua_filehandler_read(wtap *wth, wtap_rec *rec, Buffer *buf,
wtap_block_unref(rec->block);
rec->block = NULL;
fp = push_File(L, wth->fh);
fp = push_File(L, wth_fh);
fc = push_CaptureInfo(L, wth, FALSE);
fi = push_FrameInfo(L, rec, buf);
@ -298,13 +287,22 @@ wslua_filehandler_read(wtap *wth, wtap_rec *rec, Buffer *buf,
return (retval == 1);
}
/* Classic wtap seek_read function, called by wtap core. This must return TRUE on
* success, FALSE on error.
/* The classic wtap read routine. This returns TRUE if it found the next packet,
* else FALSE.
* If it finds a frame/packet, it should set the pseudo-header info (ie, let Lua set it).
* Also Lua needs to set data_offset to the beginning of the line we're returning.
* This will be the seek_off parameter when this frame is re-read.
*/
static gboolean
wslua_filehandler_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info)
wslua_filehandler_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *offset)
{
return wslua_filehandler_read_packet(wth, wth->fh, rec, buf, err, err_info, offset);
}
static gboolean
wslua_filehandler_seek_read_packet(wtap *wth, gint64 seek_off, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info)
{
FileHandler fh = (FileHandler)(wth->wslua_data);
int retval = -1;
@ -313,11 +311,6 @@ wslua_filehandler_seek_read(wtap *wth, gint64 seek_off,
CaptureInfo *fc = NULL;
FrameInfo *fi = NULL;
if (fh->removed) {
/* Return success when removed during reloading Lua plugins */
return TRUE;
}
INIT_FILEHANDLER_ROUTINE(seek_read,FALSE,err,err_info);
/* Reset errno */
@ -358,6 +351,43 @@ wslua_filehandler_seek_read(wtap *wth, gint64 seek_off,
return (retval == 1);
}
/* Default FileHandler:seek_read() implementation.
* Do a standard file_seek() and then call FileHandler:read().
*/
static gboolean
wslua_filehandler_seek_read_default(wtap *wth, gint64 seek_off, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info)
{
gint64 offset = file_seek(wth->random_fh, seek_off, SEEK_SET, err);
if (offset < 0) {
return FALSE;
}
return wslua_filehandler_read_packet(wth, wth->random_fh, rec, buf, err, err_info, &offset);
}
/* Classic wtap seek_read function, called by wtap core. This must return TRUE on
* success, FALSE on error.
*/
static gboolean
wslua_filehandler_seek_read(wtap *wth, gint64 seek_off, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info)
{
FileHandler fh = (FileHandler)(wth->wslua_data);
if (fh->removed) {
/* Return success when removed during reloading Lua plugins */
return TRUE;
}
if (fh->seek_read_ref != LUA_NOREF) {
return wslua_filehandler_seek_read_packet(wth, seek_off, rec, buf, err, err_info);
} else {
return wslua_filehandler_seek_read_default(wth, seek_off, rec, buf, err, err_info);
}
}
/* Classic wtap close function, called by wtap core.
*/
static void
@ -748,8 +778,7 @@ static gboolean verify_filehandler_complete(FileHandler fh) {
(!fh->is_reader ||
(fh->is_reader &&
fh->read_open_ref != LUA_NOREF &&
fh->read_ref != LUA_NOREF &&
fh->seek_read_ref != LUA_NOREF)) &&
fh->read_ref != LUA_NOREF)) &&
(!fh->is_writer ||
(fh->is_writer &&
fh->can_write_encap_ref != LUA_NOREF &&
@ -932,6 +961,8 @@ WSLUA_ATTRIBUTE_FUNC_SETTER(FileHandler,read);
return fh_read(file, capture, frame)
end
----
Since 3.6.0, it's possible to omit the `FileHandler:seek_read()` function to get a default seek_read implementation.
*/
WSLUA_ATTRIBUTE_FUNC_SETTER(FileHandler,seek_read);