wireshark/sharkd.c
Adam Morrison 11b3663004 Fixed a bug related to epan initialization
In various places, <program>_epan_new was called before setting the
provider, so the wth field was null. This fix is necessary for the
next commit, adding Secrets Description Block, as it uses this field.

Change-Id: Ice8ee01c56b3e04fc71d7b2c659d9635cb366951
Reviewed-on: https://code.wireshark.org/review/28868
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
2018-08-22 06:18:11 +00:00

822 lines
22 KiB
C

/* 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 <wsutil/clopts_common.h>
#include <wsutil/cmdarg_err.h>
#include <wsutil/crash_info.h>
#include <wsutil/filesystem.h>
#include <wsutil/file_util.h>
#include <wsutil/privileges.h>
#include <wsutil/report_message.h>
#include <version_info.h>
#include <wiretap/wtap_opttypes.h>
#include <wiretap/pcapng.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 "epan/register.h"
#include <epan/epan_dissect.h>
#include <epan/tap.h>
#include <epan/uat-int.h>
#include <codecs/codecs.h>
#include "log.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 failure_warning_message(const char *msg_format, va_list ap);
static void open_failure_message(const char *filename, int err,
gboolean for_writing);
static void read_failure_message(const char *filename, int err);
static void write_failure_message(const char *filename, int err);
static void failure_message_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[])
{
GString *comp_info_str;
GString *runtime_info_str;
char *init_progfile_dir_error;
char *err_msg = NULL;
e_prefs *prefs_p;
int ret = EXIT_SUCCESS;
cmdarg_err_init(failure_warning_message, failure_message_cont);
/*
* 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.
*/
init_progfile_dir_error = init_progfile_dir(argv[0]);
if (init_progfile_dir_error != NULL) {
fprintf(stderr, "sharkd: Can't get pathname of sharkd program: %s.\n",
init_progfile_dir_error);
}
/* Get the compile-time version information string */
comp_info_str = get_compiled_version_info(NULL, epan_get_compiled_version_info);
/* Get the run-time version information string */
runtime_info_str = get_runtime_version_info(epan_get_runtime_version_info);
/* Add it to the information to be reported on a crash. */
ws_add_crash_info("Sharkd (Wireshark) %s\n"
"\n"
"%s"
"\n"
"%s",
get_ws_vcs_version_info(), comp_info_str->str, runtime_info_str->str);
g_string_free(comp_info_str, TRUE);
g_string_free(runtime_info_str, TRUE);
if (sharkd_init(argc, argv) < 0)
{
printf("cannot initialize sharkd\n");
ret = INIT_FAILED;
goto clean_exit;
}
init_report_message(failure_warning_message, failure_warning_message,
open_failure_message, read_failure_message,
write_failure_message);
timestamp_set_type(TS_RELATIVE);
timestamp_set_precision(TS_PREC_AUTO);
timestamp_set_seconds_type(TS_SECONDS_DEFAULT);
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(register_all_protocols, register_all_protocol_handoffs, NULL,
NULL)) {
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();
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_user_comment
};
return epan_new(&cf->provider, &funcs);
}
static gboolean
process_packet(capture_file *cf, epan_dissect_t *edt,
gint64 offset, wtap_rec *rec, const guchar *pd)
{
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(&cf->provider, &fdlocal, pd),
&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;
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);
}
while (wtap_read(cf->provider.wth, &err, &err_info, &data_offset)) {
if (process_packet(cf, edt, data_offset, wtap_get_rec(cf->provider.wth),
wtap_get_buf_ptr(cf->provider.wth))) {
/* 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;
}
/* 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("sharkd", 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);
return CF_OK;
fail:
cfile_open_failure_message("sharkd", fname, *err, err_info);
return CF_ERROR;
}
/*
* General errors and warnings are reported with an console message
* in sharkd.
*/
static void
failure_warning_message(const char *msg_format, va_list ap)
{
fprintf(stderr, "sharkd: ");
vfprintf(stderr, msg_format, ap);
fprintf(stderr, "\n");
}
/*
* Open/create errors are reported with an console message in sharkd.
*/
static void
open_failure_message(const char *filename, int err, gboolean for_writing)
{
fprintf(stderr, "sharkd: ");
fprintf(stderr, file_open_error_message(err, for_writing), filename);
fprintf(stderr, "\n");
}
/*
* Read errors are reported with an console message in sharkd.
*/
static void
read_failure_message(const char *filename, int err)
{
cmdarg_err("An error occurred while reading from the file \"%s\": %s.",
filename, g_strerror(err));
}
/*
* Write errors are reported with an console message in sharkd.
*/
static void
write_failure_message(const char *filename, int err)
{
cmdarg_err("An error occurred while writing to the file \"%s\": %s.",
filename, g_strerror(err));
}
/*
* Report additional information for an error in command-line arguments.
*/
static void
failure_message_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);
}
int
sharkd_dissect_request(guint32 framenum, guint32 frame_ref_num, guint32 prev_dis_num, sharkd_dissect_func_t cb, guint32 dissect_flags, void *data)
{
frame_data *fdata;
column_info *cinfo = (dissect_flags & SHARKD_DISSECT_FLAG_COLUMNS) ? &cfile.cinfo : NULL;
epan_dissect_t edt;
gboolean create_proto_tree;
wtap_rec rec; /* Record metadata */
Buffer buf; /* Record data */
int err;
char *err_info = NULL;
fdata = sharkd_get_frame(framenum);
if (fdata == NULL)
return -1;
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1500);
if (!wtap_seek_read(cfile.provider.wth, fdata->file_off, &rec, &buf, &err, &err_info)) {
ws_buffer_free(&buf);
return -1; /* 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->flags.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->flags.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);
epan_dissect_cleanup(&edt);
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
return 0;
}
/* based on packet_list_dissect_and_cache_record */
int
sharkd_dissect_columns(frame_data *fdata, guint32 frame_ref_num, guint32 prev_dis_num, column_info *cinfo, gboolean dissect_color)
{
epan_dissect_t edt;
gboolean create_proto_tree;
wtap_rec rec; /* Record metadata */
Buffer buf; /* Record data */
int err;
char *err_info = NULL;
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1500);
if (!wtap_seek_read(cfile.provider.wth, fdata->file_off, &rec, &buf, &err, &err_info)) {
col_fill_in_error(cinfo, fdata, FALSE, FALSE /* fill_fd_columns */);
ws_buffer_free(&buf);
return -1; /* error reading the record */
}
create_proto_tree = (dissect_color && color_filters_used()) || (cinfo && have_custom_cols(cinfo));
epan_dissect_init(&edt, cfile.epan, create_proto_tree, FALSE /* proto_tree_visible */);
if (dissect_color) {
color_filters_prime_edt(&edt);
fdata->flags.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->flags.ref_time = (fdata->num == 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 */);
}
epan_dissect_cleanup(&edt);
wtap_rec_cleanup(&rec);
ws_buffer_free(&buf);
return 0;
}
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, 1500);
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->flags.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(&cfile.provider, fdata, ws_buffer_start_ptr(&buf)),
fdata, cinfo);
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;
}
frames_count = cfile.count;
wtap_rec_init(&rec);
ws_buffer_init(&buf, 1500);
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->flags.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 */
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;
}
const char *
sharkd_get_user_comment(const frame_data *fd)
{
return cap_file_provider_get_user_comment(&cfile.provider, fd);
}
int
sharkd_set_user_comment(frame_data *fd, const gchar *new_comment)
{
cap_file_provider_set_user_comment(&cfile.provider, fd, new_comment);
return 0;
}
#include "version.h"
const char *sharkd_version(void)
{
/* based on get_ws_vcs_version_info(), but shorter */
#ifdef VCSVERSION
return VCSVERSION;
#else
return VERSION;
#endif
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/