diff options
Diffstat (limited to 'sharkd.c')
| -rw-r--r-- | sharkd.c | 758 |
1 files changed, 758 insertions, 0 deletions
diff --git a/sharkd.c b/sharkd.c new file mode 100644 index 00000000..5603b6b4 --- /dev/null +++ b/sharkd.c @@ -0,0 +1,758 @@ +/* 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> +#define WS_LOG_DOMAIN LOG_DOMAIN_MAIN + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <limits.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/filesystem.h> +#include <wsutil/file_util.h> +#include <wsutil/privileges.h> +#include <wsutil/report_message.h> +#include <wsutil/wslog.h> +#include <wsutil/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 "wsutil/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 SHARKD_INIT_FAILED 1 +#define SHARKD_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, SHARKD_INIT_FAILED); + + ws_noisy("Finished log init and parsing command line log arguments"); + + /* + * 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 = SHARKD_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 = SHARKD_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_get_table_by_name("MaxMind Database Paths")->reset_cb(); +#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) +{ + const frame_data *fd = NULL; + if (prov->ref && prov->ref->num == frame_num) { + fd = prov->ref; + } else if (prov->prev_dis && prov->prev_dis->num == frame_num) { + fd = prov->prev_dis; + } else if (prov->prev_cap && prov->prev_cap->num == frame_num) { + fd = prov->prev_cap; + } else if (prov->frames) { + fd = frame_data_sequence_find(prov->frames, frame_num); + } + + return (fd && fd->has_ts) ? &fd->abs_ts : 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.fd.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) && edt->pi.fd->dependent_frames) { + g_hash_table_foreach(edt->pi.fd->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_listeners_require_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, NULL)) { + 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; +} |