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wireshark/sharkd.c

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/* sharkd.c
*
* Daemon variant of Wireshark
*
* 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <signal.h>
#include <glib.h>
#include <epan/exceptions.h>
#include <epan/epan.h>
#include <ui/clopts_common.h>
#include <ui/cmdarg_err.h>
#include <wsutil/filesystem.h>
#include <wsutil/file_util.h>
#include <wsutil/privileges.h>
#include <wsutil/report_message.h>
#include <wsutil/wslog.h>
#include <ui/version_info.h>
#include <wiretap/wtap_opttypes.h>
#include <epan/decode_as.h>
#include <epan/timestamp.h>
#include <epan/packet.h>
#include "frame_tvbuff.h"
#include <epan/disabled_protos.h>
#include <epan/prefs.h>
#include <epan/column.h>
#include <epan/print.h>
#include <epan/addr_resolv.h>
#include "ui/util.h"
#include "ui/ws_ui_util.h"
#include "ui/decode_as_utils.h"
#include "ui/filter_files.h"
#include "ui/tap_export_pdu.h"
#include "ui/failure_message.h"
#include "wtap.h"
#include <epan/epan_dissect.h>
#include <epan/tap.h>
#include <epan/uat-int.h>
#include <epan/secrets.h>
#include <wsutil/codecs.h>
#include <wsutil/str_util.h>
#include <wsutil/utf8_entities.h>
#ifdef HAVE_PLUGINS
#include <wsutil/plugins.h>
#endif
#include "sharkd.h"
#define INIT_FAILED 1
#define EPAN_INIT_FAIL 2
capture_file cfile;
static guint32 cum_bytes;
static frame_data ref_frame;
static void sharkd_cmdarg_err(const char *msg_format, va_list ap);
static void sharkd_cmdarg_err_cont(const char *msg_format, va_list ap);
static void
print_current_user(void)
{
gchar *cur_user, *cur_group;
if (started_with_special_privs()) {
cur_user = get_cur_username();
cur_group = get_cur_groupname();
fprintf(stderr, "Running as user \"%s\" and group \"%s\".",
cur_user, cur_group);
g_free(cur_user);
g_free(cur_group);
if (running_with_special_privs()) {
fprintf(stderr, " This could be dangerous.");
}
fprintf(stderr, "\n");
}
}
int
main(int argc, char *argv[])
{
char *configuration_init_error;
char *err_msg = NULL;
e_prefs *prefs_p;
int ret = EXIT_SUCCESS;
static const struct report_message_routines sharkd_report_routines = {
failure_message,
failure_message,
open_failure_message,
read_failure_message,
write_failure_message,
cfile_open_failure_message,
cfile_dump_open_failure_message,
cfile_read_failure_message,
cfile_write_failure_message,
cfile_close_failure_message
};
cmdarg_err_init(sharkd_cmdarg_err, sharkd_cmdarg_err_cont);
/* Initialize log handler early so we can have proper logging during startup. */
ws_log_init("sharkd", vcmdarg_err);
/* Early logging command-line initialization. */
ws_log_parse_args(&argc, argv, vcmdarg_err, INIT_FAILED);
/*
* Get credential information for later use, and drop privileges
* before doing anything else.
* Let the user know if anything happened.
*/
init_process_policies();
relinquish_special_privs_perm();
print_current_user();
/*
* Attempt to get the pathname of the executable file.
*/
configuration_init_error = configuration_init(argv[0], NULL);
if (configuration_init_error != NULL) {
fprintf(stderr, "sharkd: Can't get pathname of sharkd program: %s.\n",
configuration_init_error);
}
/* Initialize the version information. */
ws_init_version_info("Sharkd",
epan_gather_compile_info,
epan_gather_runtime_info);
if (sharkd_init(argc, argv) < 0)
{
printf("cannot initialize sharkd\n");
ret = INIT_FAILED;
goto clean_exit;
}
init_report_message("sharkd", &sharkd_report_routines);
timestamp_set_type(TS_RELATIVE);
timestamp_set_precision(TS_PREC_AUTO);
timestamp_set_seconds_type(TS_SECONDS_DEFAULT);
/*
* Libwiretap must be initialized before libwireshark is, so that
* dissection-time handlers for file-type-dependent blocks can
* register using the file type/subtype value for the file type.
*/
wtap_init(TRUE);
/* Register all dissectors; we must do this before checking for the
"-G" flag, as the "-G" flag dumps information registered by the
dissectors, and we must do it before we read the preferences, in
case any dissectors register preferences. */
if (!epan_init(NULL, NULL, TRUE)) {
ret = EPAN_INIT_FAIL;
goto clean_exit;
}
codecs_init();
/* Load libwireshark settings from the current profile. */
prefs_p = epan_load_settings();
read_filter_list(CFILTER_LIST);
if (!color_filters_init(&err_msg, NULL)) {
fprintf(stderr, "%s\n", err_msg);
g_free(err_msg);
}
cap_file_init(&cfile);
/* Notify all registered modules that have had any of their preferences
changed either from one of the preferences file or from the command
line that their preferences have changed. */
prefs_apply_all();
/* Build the column format array */
build_column_format_array(&cfile.cinfo, prefs_p->num_cols, TRUE);
#ifdef HAVE_MAXMINDDB
/* mmdbresolve is started from mmdb_resolve_start(), which is called from epan_load_settings via: read_prefs -> (...) uat_load_all -> maxmind_db_post_update_cb.
* Need to stop it, otherwise all sharkd will have same mmdbresolve process, including pipe descriptors to read and write. */
uat_clear(uat_get_table_by_name("MaxMind Database Paths"));
#endif
ret = sharkd_loop(argc, argv);
clean_exit:
col_cleanup(&cfile.cinfo);
free_filter_lists();
codecs_cleanup();
wtap_cleanup();
free_progdirs();
return ret;
}
static const nstime_t *
sharkd_get_frame_ts(struct packet_provider_data *prov, guint32 frame_num)
{
if (prov->ref && prov->ref->num == frame_num)
return &prov->ref->abs_ts;
if (prov->prev_dis && prov->prev_dis->num == frame_num)
return &prov->prev_dis->abs_ts;
if (prov->prev_cap && prov->prev_cap->num == frame_num)
return &prov->prev_cap->abs_ts;
if (prov->frames) {
frame_data *fd = frame_data_sequence_find(prov->frames, frame_num);
return (fd) ? &fd->abs_ts : NULL;
}
return NULL;
}
static epan_t *
sharkd_epan_new(capture_file *cf)
{
static const struct packet_provider_funcs funcs = {
sharkd_get_frame_ts,
cap_file_provider_get_interface_name,
cap_file_provider_get_interface_description,
cap_file_provider_get_modified_block
};
return epan_new(&cf->provider, &funcs);
}
static gboolean
process_packet(capture_file *cf, epan_dissect_t *edt,
gint64 offset, wtap_rec *rec, Buffer *buf)
{
frame_data fdlocal;
gboolean passed;
/* If we're not running a display filter and we're not printing any
packet information, we don't need to do a dissection. This means
that all packets can be marked as 'passed'. */
passed = TRUE;
/* The frame number of this packet, if we add it to the set of frames,
would be one more than the count of frames in the file so far. */
frame_data_init(&fdlocal, cf->count + 1, rec, offset, cum_bytes);
/* If we're going to print packet information, or we're going to
run a read filter, or display filter, or we're going to process taps, set up to
do a dissection and do so. */
if (edt) {
if (gbl_resolv_flags.mac_name || gbl_resolv_flags.network_name ||
gbl_resolv_flags.transport_name)
/* Grab any resolved addresses */
host_name_lookup_process();
/* If we're running a read filter, prime the epan_dissect_t with that
filter. */
if (cf->rfcode)
epan_dissect_prime_with_dfilter(edt, cf->rfcode);
if (cf->dfcode)
epan_dissect_prime_with_dfilter(edt, cf->dfcode);
/* This is the first and only pass, so prime the epan_dissect_t
with the hfids postdissectors want on the first pass. */
prime_epan_dissect_with_postdissector_wanted_hfids(edt);
frame_data_set_before_dissect(&fdlocal, &cf->elapsed_time,
&cf->provider.ref, cf->provider.prev_dis);
if (cf->provider.ref == &fdlocal) {
ref_frame = fdlocal;
cf->provider.ref = &ref_frame;
}
epan_dissect_run(edt, cf->cd_t, rec,
frame_tvbuff_new_buffer(&cf->provider, &fdlocal, buf),
&fdlocal, NULL);
/* Run the read filter if we have one. */
if (cf->rfcode)
passed = dfilter_apply_edt(cf->rfcode, edt);
}
if (passed) {
frame_data_set_after_dissect(&fdlocal, &cum_bytes);
cf->provider.prev_cap = cf->provider.prev_dis = frame_data_sequence_add(cf->provider.frames, &fdlocal);
/* If we're not doing dissection then there won't be any dependent frames.
* More importantly, edt.pi.dependent_frames won't be initialized because
* epan hasn't been initialized.
* if we *are* doing dissection, then mark the dependent frames, but only
* if a display filter was given and it matches this packet.
*/
if (edt && cf->dfcode) {
if (dfilter_apply_edt(cf->dfcode, edt)) {
g_slist_foreach(edt->pi.dependent_frames, find_and_mark_frame_depended_upon, cf->provider.frames);
}
}
cf->count++;
} else {
/* if we don't add it to the frame_data_sequence, clean it up right now
* to avoid leaks */
frame_data_destroy(&fdlocal);
}
if (edt)
epan_dissect_reset(edt);
return passed;
}
static int
load_cap_file(capture_file *cf, int max_packet_count, gint64 max_byte_count)
{
int err;
gchar *err_info = NULL;
gint64 data_offset;
wtap_rec rec;
Buffer buf;
epan_dissect_t *edt = NULL;
{
/* Allocate a frame_data_sequence for all the frames. */
cf->provider.frames = new_frame_data_sequence();
{
gboolean create_proto_tree;
/*
* Determine whether we need to create a protocol tree.
* We do if:
*
* we're going to apply a read filter;
*
* we're going to apply a display filter;
*
* a postdissector wants field values or protocols
* on the first pass.
*/
create_proto_tree =
(cf->rfcode != NULL || cf->dfcode != NULL || postdissectors_want_hfids());
/* We're not going to display the protocol tree on this pass,
so it's not going to be "visible". */
edt = epan_dissect_new(cf->epan, create_proto_tree, FALSE);
}
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1514);
while (wtap_read(cf->provider.wth, &rec, &buf, &err, &err_info, &data_offset)) {
if (process_packet(cf, edt, data_offset, &rec, &buf)) {
wtap_rec_reset(&rec);
/* Stop reading if we have the maximum number of packets;
* When the -c option has not been used, max_packet_count
* starts at 0, which practically means, never stop reading.
* (unless we roll over max_packet_count ?)
*/
if ( (--max_packet_count == 0) || (max_byte_count != 0 && data_offset >= max_byte_count)) {
err = 0; /* This is not an error */
break;
}
}
}
if (edt) {
epan_dissect_free(edt);
edt = NULL;
}
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
/* Close the sequential I/O side, to free up memory it requires. */
wtap_sequential_close(cf->provider.wth);
/* Allow the protocol dissectors to free up memory that they
* don't need after the sequential run-through of the packets. */
postseq_cleanup_all_protocols();
cf->provider.prev_dis = NULL;
cf->provider.prev_cap = NULL;
}
if (err != 0) {
cfile_read_failure_message(cf->filename, err, err_info);
}
return err;
}
cf_status_t
cf_open(capture_file *cf, const char *fname, unsigned int type, gboolean is_tempfile, int *err)
{
wtap *wth;
gchar *err_info;
wth = wtap_open_offline(fname, type, err, &err_info, TRUE);
if (wth == NULL)
goto fail;
/* The open succeeded. Fill in the information for this file. */
cf->provider.wth = wth;
cf->f_datalen = 0; /* not used, but set it anyway */
/* Set the file name because we need it to set the follow stream filter.
XXX - is that still true? We need it for other reasons, though,
in any case. */
cf->filename = g_strdup(fname);
/* Indicate whether it's a permanent or temporary file. */
cf->is_tempfile = is_tempfile;
/* No user changes yet. */
cf->unsaved_changes = FALSE;
cf->cd_t = wtap_file_type_subtype(cf->provider.wth);
cf->open_type = type;
cf->count = 0;
cf->drops_known = FALSE;
cf->drops = 0;
cf->snap = wtap_snapshot_length(cf->provider.wth);
nstime_set_zero(&cf->elapsed_time);
cf->provider.ref = NULL;
cf->provider.prev_dis = NULL;
cf->provider.prev_cap = NULL;
/* Create new epan session for dissection. */
epan_free(cf->epan);
cf->epan = sharkd_epan_new(cf);
cf->state = FILE_READ_IN_PROGRESS;
wtap_set_cb_new_ipv4(cf->provider.wth, add_ipv4_name);
wtap_set_cb_new_ipv6(cf->provider.wth, (wtap_new_ipv6_callback_t) add_ipv6_name);
wtap_set_cb_new_secrets(cf->provider.wth, secrets_wtap_callback);
return CF_OK;
fail:
cfile_open_failure_message(fname, *err, err_info);
return CF_ERROR;
}
/*
* Report an error in command-line arguments.
*/
static void
sharkd_cmdarg_err(const char *msg_format, va_list ap)
{
fprintf(stderr, "sharkd: ");
vfprintf(stderr, msg_format, ap);
fprintf(stderr, "\n");
}
/*
* Report additional information for an error in command-line arguments.
*/
static void
sharkd_cmdarg_err_cont(const char *msg_format, va_list ap)
{
vfprintf(stderr, msg_format, ap);
fprintf(stderr, "\n");
}
cf_status_t
sharkd_cf_open(const char *fname, unsigned int type, gboolean is_tempfile, int *err)
{
return cf_open(&cfile, fname, type, is_tempfile, err);
}
int
sharkd_load_cap_file(void)
{
return load_cap_file(&cfile, 0, 0);
}
frame_data *
sharkd_get_frame(guint32 framenum)
{
return frame_data_sequence_find(cfile.provider.frames, framenum);
}
enum dissect_request_status
sharkd_dissect_request(guint32 framenum, guint32 frame_ref_num,
guint32 prev_dis_num, wtap_rec *rec, Buffer *buf,
column_info *cinfo, guint32 dissect_flags,
sharkd_dissect_func_t cb, void *data,
int *err, gchar **err_info)
{
frame_data *fdata;
epan_dissect_t edt;
gboolean create_proto_tree;
fdata = sharkd_get_frame(framenum);
if (fdata == NULL)
return DISSECT_REQUEST_NO_SUCH_FRAME;
if (!wtap_seek_read(cfile.provider.wth, fdata->file_off, rec, buf, err, err_info)) {
if (cinfo != NULL)
col_fill_in_error(cinfo, fdata, FALSE, FALSE /* fill_fd_columns */);
return DISSECT_REQUEST_READ_ERROR; /* error reading the record */
}
create_proto_tree = ((dissect_flags & SHARKD_DISSECT_FLAG_PROTO_TREE) ||
((dissect_flags & SHARKD_DISSECT_FLAG_COLOR) && color_filters_used()) ||
(cinfo && have_custom_cols(cinfo)));
epan_dissect_init(&edt, cfile.epan, create_proto_tree, (dissect_flags & SHARKD_DISSECT_FLAG_PROTO_TREE));
if (dissect_flags & SHARKD_DISSECT_FLAG_COLOR) {
color_filters_prime_edt(&edt);
fdata->need_colorize = 1;
}
if (cinfo)
col_custom_prime_edt(&edt, cinfo);
/*
* XXX - need to catch an OutOfMemoryError exception and
* attempt to recover from it.
*/
fdata->ref_time = (framenum == frame_ref_num);
fdata->frame_ref_num = frame_ref_num;
fdata->prev_dis_num = prev_dis_num;
epan_dissect_run(&edt, cfile.cd_t, rec,
frame_tvbuff_new_buffer(&cfile.provider, fdata, buf),
fdata, cinfo);
if (cinfo) {
/* "Stringify" non frame_data vals */
epan_dissect_fill_in_columns(&edt, FALSE, TRUE/* fill_fd_columns */);
}
cb(&edt, (dissect_flags & SHARKD_DISSECT_FLAG_PROTO_TREE) ? edt.tree : NULL,
cinfo, (dissect_flags & SHARKD_DISSECT_FLAG_BYTES) ? edt.pi.data_src : NULL,
data);
wtap_rec_reset(rec);
epan_dissect_cleanup(&edt);
return DISSECT_REQUEST_SUCCESS;
}
int
sharkd_retap(void)
{
guint32 framenum;
frame_data *fdata;
Buffer buf;
wtap_rec rec;
int err;
char *err_info = NULL;
guint tap_flags;
gboolean create_proto_tree;
epan_dissect_t edt;
column_info *cinfo;
/* Get the union of the flags for all tap listeners. */
tap_flags = union_of_tap_listener_flags();
/* If any tap listeners require the columns, construct them. */
cinfo = (tap_flags & TL_REQUIRES_COLUMNS) ? &cfile.cinfo : NULL;
/*
* Determine whether we need to create a protocol tree.
* We do if:
*
* one of the tap listeners is going to apply a filter;
*
* one of the tap listeners requires a protocol tree.
*/
create_proto_tree =
(have_filtering_tap_listeners() || (tap_flags & TL_REQUIRES_PROTO_TREE));
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1514);
epan_dissect_init(&edt, cfile.epan, create_proto_tree, FALSE);
reset_tap_listeners();
for (framenum = 1; framenum <= cfile.count; framenum++) {
fdata = sharkd_get_frame(framenum);
if (!wtap_seek_read(cfile.provider.wth, fdata->file_off, &rec, &buf, &err, &err_info))
break;
fdata->ref_time = FALSE;
fdata->frame_ref_num = (framenum != 1) ? 1 : 0;
fdata->prev_dis_num = framenum - 1;
epan_dissect_run_with_taps(&edt, cfile.cd_t, &rec,
frame_tvbuff_new_buffer(&cfile.provider, fdata, &buf),
fdata, cinfo);
wtap_rec_reset(&rec);
epan_dissect_reset(&edt);
}
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
epan_dissect_cleanup(&edt);
draw_tap_listeners(TRUE);
return 0;
}
int
sharkd_filter(const char *dftext, guint8 **result)
{
dfilter_t *dfcode = NULL;
guint32 framenum, prev_dis_num = 0;
guint32 frames_count;
Buffer buf;
wtap_rec rec;
int err;
char *err_info = NULL;
guint8 *result_bits;
guint8 passed_bits;
epan_dissect_t edt;
if (!dfilter_compile(dftext, &dfcode, &err_info)) {
g_free(err_info);
return -1;
}
/* if dfilter_compile() success, but (dfcode == NULL) all frames are matching */
if (dfcode == NULL) {
*result = NULL;
return 0;
}
frames_count = cfile.count;
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1514);
epan_dissect_init(&edt, cfile.epan, TRUE, FALSE);
passed_bits = 0;
result_bits = (guint8 *) g_malloc(2 + (frames_count / 8));
for (framenum = 1; framenum <= frames_count; framenum++) {
frame_data *fdata = sharkd_get_frame(framenum);
if ((framenum & 7) == 0) {
result_bits[(framenum / 8) - 1] = passed_bits;
passed_bits = 0;
}
if (!wtap_seek_read(cfile.provider.wth, fdata->file_off, &rec, &buf, &err, &err_info))
break;
/* frame_data_set_before_dissect */
epan_dissect_prime_with_dfilter(&edt, dfcode);
fdata->ref_time = FALSE;
fdata->frame_ref_num = (framenum != 1) ? 1 : 0;
fdata->prev_dis_num = prev_dis_num;
epan_dissect_run(&edt, cfile.cd_t, &rec,
frame_tvbuff_new_buffer(&cfile.provider, fdata, &buf),
fdata, NULL);
if (dfilter_apply_edt(dfcode, &edt)) {
passed_bits |= (1 << (framenum % 8));
prev_dis_num = framenum;
}
/* if passed or ref -> frame_data_set_after_dissect */
wtap_rec_reset(&rec);
epan_dissect_reset(&edt);
}
if ((framenum & 7) == 0)
framenum--;
result_bits[framenum / 8] = passed_bits;
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
epan_dissect_cleanup(&edt);
dfilter_free(dfcode);
*result = result_bits;
return framenum;
}
/*
* Get the modified block if available, nothing otherwise.
* Must be cloned if changes desired.
*/
wtap_block_t
sharkd_get_modified_block(const frame_data *fd)
{
return cap_file_provider_get_modified_block(&cfile.provider, fd);
}
/*
* Gets the modified block if available, otherwise the packet's default block,
* or a new packet block.
* User must wtap_block_unref() it when done.
*/
wtap_block_t
sharkd_get_packet_block(const frame_data *fd)
{
if (fd->has_modified_block)
return wtap_block_ref(cap_file_provider_get_modified_block(&cfile.provider, fd));
else
{
wtap_rec rec; /* Record metadata */
Buffer buf; /* Record data */
wtap_block_t block;
int err;
gchar *err_info;
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1514);
if (!wtap_seek_read(cfile.provider.wth, fd->file_off, &rec, &buf, &err, &err_info))
{ /* XXX, what we can do here? */ }
/* rec.block is owned by the record, steal it before it is gone. */
block = wtap_block_ref(rec.block);
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
return block;
}
}
int
sharkd_set_modified_block(frame_data *fd, wtap_block_t new_block)
{
cap_file_provider_set_modified_block(&cfile.provider, fd, new_block);
return 0;
}
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