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/* tap_export_pdu.c
* Routines for exporting PDUs to file
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/tap.h>
#include <epan/exported_pdu.h>
#include <epan/epan_dissect.h>
#include <wiretap/wtap.h>
#include <wiretap/wtap_opttypes.h>
#include <wsutil/os_version_info.h>
#include <wsutil/report_message.h>
#include "wsutil/version_info.h"
#include "tap_export_pdu.h"
/* Main entry point to the tap */
static tap_packet_status
export_pdu_packet(void *tapdata, packet_info *pinfo, epan_dissect_t *edt, const void *data, tap_flags_t flags _U_)
{
const exp_pdu_data_t *exp_pdu_data = (const exp_pdu_data_t *)data;
exp_pdu_t *exp_pdu_tap_data = (exp_pdu_t *)tapdata;
wtap_rec rec;
int err;
gchar *err_info;
int buffer_len;
guint8 *packet_buf;
tap_packet_status status = TAP_PACKET_DONT_REDRAW; /* no GUI, nothing to redraw */
/*
* Count this packet.
*/
exp_pdu_tap_data->framenum++;
memset(&rec, 0, sizeof rec);
buffer_len = exp_pdu_data->tvb_captured_length + exp_pdu_data->tlv_buffer_len;
packet_buf = (guint8 *)g_malloc(buffer_len);
if(exp_pdu_data->tlv_buffer_len > 0){
memcpy(packet_buf, exp_pdu_data->tlv_buffer, exp_pdu_data->tlv_buffer_len);
}
if(exp_pdu_data->tvb_captured_length > 0){
tvb_memcpy(exp_pdu_data->pdu_tvb, packet_buf+exp_pdu_data->tlv_buffer_len, 0, exp_pdu_data->tvb_captured_length);
}
rec.rec_type = REC_TYPE_PACKET;
rec.presence_flags = WTAP_HAS_CAP_LEN|WTAP_HAS_INTERFACE_ID|WTAP_HAS_TS;
rec.ts.secs = pinfo->abs_ts.secs;
rec.ts.nsecs = pinfo->abs_ts.nsecs;
rec.rec_header.packet_header.caplen = buffer_len;
rec.rec_header.packet_header.len = exp_pdu_data->tvb_reported_length + exp_pdu_data->tlv_buffer_len;
rec.rec_header.packet_header.pkt_encap = exp_pdu_tap_data->pkt_encap;
/* rec.opt_block is not modified by wtap_dump, but if for some reason the
* epan_get_modified_block() or pinfo->rec->block are invalidated,
* copying it here does not hurt. (Can invalidation really happen?) */
if (pinfo->fd->has_modified_block) {
rec.block = epan_get_modified_block(edt->session, pinfo->fd);
rec.block_was_modified = TRUE;
} else {
rec.block = pinfo->rec->block;
}
/* XXX: should the rec.rec_header.packet_header.pseudo_header be set to the pinfo's pseudo-header? */
if (!wtap_dump(exp_pdu_tap_data->wdh, &rec, packet_buf, &err, &err_info)) {
report_cfile_write_failure(NULL, exp_pdu_tap_data->pathname,
err, err_info, exp_pdu_tap_data->framenum,
wtap_dump_file_type_subtype(exp_pdu_tap_data->wdh));
status = TAP_PACKET_FAILED;
}
g_free(packet_buf);
return status;
}
gboolean
exp_pdu_open(exp_pdu_t *exp_pdu_tap_data, char *pathname,
int file_type_subtype, int fd, const char *comment,
int *err, gchar **err_info)
{
/* pcapng defs */
wtap_block_t shb_hdr;
wtap_block_t int_data;
wtapng_if_descr_mandatory_t *int_data_mand;
GString *os_info_str;
gsize opt_len;
gchar *opt_str;
/*
* If the file format supports a section block, and the section
* block supports comments, create data for it.
*/
if (wtap_file_type_subtype_supports_block(file_type_subtype,
WTAP_BLOCK_SECTION) != BLOCK_NOT_SUPPORTED &&
wtap_file_type_subtype_supports_option(file_type_subtype,
WTAP_BLOCK_SECTION,
OPT_COMMENT) != OPTION_NOT_SUPPORTED) {
os_info_str = g_string_new("");
get_os_version_info(os_info_str);
shb_hdr = wtap_block_create(WTAP_BLOCK_SECTION);
/* options */
wtap_block_add_string_option(shb_hdr, OPT_COMMENT, comment, strlen(comment));
/*
* UTF-8 string containing the name of the operating system used to
* create this section.
*/
opt_len = os_info_str->len;
opt_str = g_string_free(os_info_str, FALSE);
if (opt_str) {
wtap_block_add_string_option(shb_hdr, OPT_SHB_OS, opt_str, opt_len);
g_free(opt_str);
}
/*
* UTF-8 string containing the name of the application used to create
* this section.
*/
wtap_block_add_string_option_format(shb_hdr, OPT_SHB_USERAPPL, "%s",
get_appname_and_version());
exp_pdu_tap_data->shb_hdrs = g_array_new(FALSE, FALSE, sizeof(wtap_block_t));
g_array_append_val(exp_pdu_tap_data->shb_hdrs, shb_hdr);
} else {
exp_pdu_tap_data->shb_hdrs = NULL;
}
/*
* Create fake interface information for files that support (meaning
* "require") interface information and per-packet interface IDs.
*/
if (wtap_file_type_subtype_supports_block(file_type_subtype,
WTAP_BLOCK_IF_ID_AND_INFO) != BLOCK_NOT_SUPPORTED) {
exp_pdu_tap_data->idb_inf = g_new(wtapng_iface_descriptions_t,1);
exp_pdu_tap_data->idb_inf->interface_data = g_array_new(FALSE, FALSE, sizeof(wtap_block_t));
/* create the fake interface data */
int_data = wtap_block_create(WTAP_BLOCK_IF_ID_AND_INFO);
int_data_mand = (wtapng_if_descr_mandatory_t*)wtap_block_get_mandatory_data(int_data);
int_data_mand->wtap_encap = exp_pdu_tap_data->pkt_encap;
int_data_mand->time_units_per_second = 1000000000; /* default nanosecond resolution */
int_data_mand->snap_len = WTAP_MAX_PACKET_SIZE_STANDARD;
wtap_block_add_string_option(int_data, OPT_IDB_NAME, "Fake IF, PDU->Export", strlen("Fake IF, PDU->Export"));
wtap_block_add_uint8_option(int_data, OPT_IDB_TSRESOL, 9);
g_array_append_val(exp_pdu_tap_data->idb_inf->interface_data, int_data);
} else {
exp_pdu_tap_data->idb_inf = NULL;
}
const wtap_dump_params params = {
.encap = exp_pdu_tap_data->pkt_encap,
.snaplen = WTAP_MAX_PACKET_SIZE_STANDARD,
.shb_hdrs = exp_pdu_tap_data->shb_hdrs,
.idb_inf = exp_pdu_tap_data->idb_inf,
};
if (fd == 1) {
exp_pdu_tap_data->wdh = wtap_dump_open_stdout(file_type_subtype,
WTAP_UNCOMPRESSED, ¶ms, err, err_info);
} else {
exp_pdu_tap_data->wdh = wtap_dump_fdopen(fd, file_type_subtype,
WTAP_UNCOMPRESSED, ¶ms, err, err_info);
}
if (exp_pdu_tap_data->wdh == NULL)
return FALSE;
exp_pdu_tap_data->pathname = pathname;
exp_pdu_tap_data->framenum = 0; /* No frames written yet */
return TRUE;
}
gboolean
exp_pdu_close(exp_pdu_t *exp_pdu_tap_data, int *err, gchar **err_info)
{
gboolean status;
status = wtap_dump_close(exp_pdu_tap_data->wdh, NULL, err, err_info);
wtap_block_array_free(exp_pdu_tap_data->shb_hdrs);
wtap_free_idb_info(exp_pdu_tap_data->idb_inf);
remove_tap_listener(exp_pdu_tap_data);
return status;
}
char *
exp_pdu_pre_open(const char *tap_name, const char *filter, exp_pdu_t *exp_pdu_tap_data)
{
GString *error_string;
/* Make sure tap is suitable for exported PDUs */
gboolean found = FALSE;
for (GSList *export_pdu_tap_name_list = get_export_pdu_tap_list();
export_pdu_tap_name_list != NULL;
export_pdu_tap_name_list = g_slist_next(export_pdu_tap_name_list)) {
if (strcmp((const char*)(export_pdu_tap_name_list->data), tap_name) == 0) {
found = TRUE;
break;
}
}
if (!found) {
return g_strdup("unsuitable for PDU export");
}
/* Register this tap listener now */
error_string = register_tap_listener(tap_name, /* The name of the tap we want to listen to */
exp_pdu_tap_data, /* instance identifier/pointer to a struct holding
* all state variables */
filter, /* pointer to a filter string */
TL_REQUIRES_PROTO_TREE, /* flags for the tap listener */
NULL,
export_pdu_packet,
NULL,
NULL);
if (error_string != NULL)
return g_string_free(error_string, FALSE);
exp_pdu_tap_data->pkt_encap = export_pdu_tap_get_encap(tap_name);
return NULL;
}
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