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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /extcap/sdjournal.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'extcap/sdjournal.c')
-rw-r--r-- | extcap/sdjournal.c | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/extcap/sdjournal.c b/extcap/sdjournal.c new file mode 100644 index 00000000..879fea87 --- /dev/null +++ b/extcap/sdjournal.c @@ -0,0 +1,472 @@ +/* sdjournal.c + * sdjournal is an extcap tool used to dump systemd journal entries. + * + * Adapted from sshdump. + * Copyright 2018, Gerald Combs and Dario Lombardo + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/* + * To do: + * - Add an option for sd_journal_open flags, e.g. SD_JOURNAL_LOCAL_ONLY. + * - Add journalctl options - --boot, --machine, --directory, etc. + */ + +#include "config.h" +#define WS_LOG_DOMAIN "sdjournal" + +#include <extcap/extcap-base.h> +#include <wsutil/interface.h> +#include <wsutil/file_util.h> +#include <wsutil/filesystem.h> +#include <wsutil/privileges.h> +#include <wsutil/wslog.h> +#include <writecap/pcapio.h> +#include <wiretap/wtap.h> + +#include <systemd/sd-journal.h> +#include <systemd/sd-id128.h> + +#include <errno.h> +#include <string.h> +#include <fcntl.h> + +#define SDJOURNAL_VERSION_MAJOR "1" +#define SDJOURNAL_VERSION_MINOR "0" +#define SDJOURNAL_VERSION_RELEASE "0" + +#define SDJOURNAL_EXTCAP_INTERFACE "sdjournal" +#define BLOCK_TYPE_SYSTEMD_JOURNAL_EXPORT 0x00000009 + +enum { + EXTCAP_BASE_OPTIONS_ENUM, + OPT_HELP, + OPT_VERSION, + OPT_START_FROM +}; + +static struct ws_option longopts[] = { + EXTCAP_BASE_OPTIONS, + { "help", ws_no_argument, NULL, OPT_HELP}, + { "version", ws_no_argument, NULL, OPT_VERSION}, + { "start-from", ws_required_argument, NULL, OPT_START_FROM}, + { 0, 0, 0, 0} +}; + +#define FLD_BOOT_ID "_BOOT_ID=" +#define FLD_BOOT_ID_LEN (8 + 1 + 33 + 1) + +// The Journal Export Format specification doesn't place limits on entry +// lengths or lines per entry. We do. +#define ENTRY_BUF_LENGTH WTAP_MAX_PACKET_SIZE_STANDARD +#define MAX_EXPORT_ENTRY_LENGTH (ENTRY_BUF_LENGTH - 4 - 4 - 4) // Block type - total length - total length + +static int sdj_dump_entries(sd_journal *jnl, FILE* fp) +{ + int ret = EXIT_SUCCESS; + uint8_t *entry_buff = g_new(uint8_t, ENTRY_BUF_LENGTH); + int jr = 0; + + /* + * Read journal entries and write them as packets. Output must + * match `journalctl --output=export`. + */ + while (jr == 0) { + char *cursor; + uint64_t pkt_rt_ts, mono_ts; + sd_id128_t boot_id; + char boot_id_str[FLD_BOOT_ID_LEN] = FLD_BOOT_ID; + uint32_t block_type = BLOCK_TYPE_SYSTEMD_JOURNAL_EXPORT; + uint32_t data_end = 8; // Block type + total length + const void *fld_data; + size_t fld_len; + uint64_t bytes_written = 0; + int err; + + memcpy(entry_buff, &block_type, 4); + + jr = sd_journal_next(jnl); + ws_debug("sd_journal_next: %d", jr); + if (jr < 0) { + ws_warning("Error fetching journal entry: %s", g_strerror(jr)); + goto end; + } else if (jr == 0) { + sd_journal_wait(jnl, (uint64_t) -1); + continue; + } + + jr = sd_journal_get_cursor(jnl, &cursor); + if (jr < 0) { + ws_warning("Error fetching cursor: %s", g_strerror(jr)); + goto end; + } + data_end += snprintf(entry_buff+data_end, MAX_EXPORT_ENTRY_LENGTH-data_end, "__CURSOR=%s\n", cursor); + free(cursor); + + jr = sd_journal_get_realtime_usec(jnl, &pkt_rt_ts); + if (jr < 0) { + ws_warning("Error fetching realtime timestamp: %s", g_strerror(jr)); + goto end; + } + data_end += snprintf(entry_buff+data_end, MAX_EXPORT_ENTRY_LENGTH-data_end, "__REALTIME_TIMESTAMP=%" PRIu64 "\n", pkt_rt_ts); + + jr = sd_journal_get_monotonic_usec(jnl, &mono_ts, &boot_id); + if (jr < 0) { + ws_warning("Error fetching monotonic timestamp: %s", g_strerror(jr)); + goto end; + } + sd_id128_to_string(boot_id, boot_id_str + strlen(FLD_BOOT_ID)); + data_end += snprintf(entry_buff+data_end, MAX_EXPORT_ENTRY_LENGTH-data_end, "__MONOTONIC_TIMESTAMP=%" PRIu64 "\n%s\n", mono_ts, boot_id_str); + ws_debug("Entry header is %u bytes", data_end); + + SD_JOURNAL_FOREACH_DATA(jnl, fld_data, fld_len) { + uint8_t *eq_ptr = (uint8_t *) memchr(fld_data, '=', fld_len); + if (!eq_ptr) { + ws_warning("Invalid field."); + goto end; + } + if (g_utf8_validate((const char *) fld_data, (ssize_t) fld_len, NULL)) { + // Allow for two trailing newlines, one here and one + // at the end of the buffer. + if (fld_len > MAX_EXPORT_ENTRY_LENGTH-data_end-2) { + ws_debug("Breaking on UTF-8 field: %u + %zd", data_end, fld_len); + break; + } + memcpy(entry_buff+data_end, fld_data, fld_len); + data_end += (uint32_t) fld_len; + entry_buff[data_end] = '\n'; + data_end++; + } else { + // \n + 64-bit size + \n + trailing \n = 11 + if (fld_len > MAX_EXPORT_ENTRY_LENGTH-data_end-11) { + ws_debug("Breaking on binary field: %u + %zd", data_end, fld_len); + break; + } + ptrdiff_t name_len = eq_ptr - (const uint8_t *) fld_data; + uint64_t le_data_len; + le_data_len = htole64(fld_len - name_len - 1); + memcpy(entry_buff+data_end, fld_data, name_len); + data_end+= name_len; + entry_buff[data_end] = '\n'; + data_end++; + memcpy(entry_buff+data_end, &le_data_len, 8); + data_end += 8; + memcpy(entry_buff+data_end, (const uint8_t *) fld_data + name_len + 1, fld_len - name_len); + data_end += fld_len - name_len; + } + } + + if (data_end % 4) { + size_t pad_len = 4 - (data_end % 4); + memset(entry_buff+data_end, '\0', pad_len); + data_end += pad_len; + } + + uint32_t total_len = data_end + 4; + memcpy (entry_buff+4, &total_len, 4); + memcpy (entry_buff+data_end, &total_len, 4); + + ws_debug("Attempting to write %u bytes", total_len); + if (!pcapng_write_block(fp, entry_buff, total_len, &bytes_written, &err)) { + ws_warning("Can't write event: %s", strerror(err)); + ret = EXIT_FAILURE; + break; + } + + fflush(fp); + } + +end: + g_free(entry_buff); + return ret; +} + +static int sdj_start_export(const int start_from_entries, const bool start_from_end, const char* fifo) +{ + FILE* fp = stdout; + uint64_t bytes_written = 0; + int err; + sd_journal *jnl = NULL; + sd_id128_t boot_id; + char boot_id_str[FLD_BOOT_ID_LEN] = FLD_BOOT_ID; + int ret = EXIT_FAILURE; + char* err_info = NULL; + char *appname; + bool success; + int jr = 0; + + if (g_strcmp0(fifo, "-")) { + /* Open or create the output file */ + fp = fopen(fifo, "wb"); + if (fp == NULL) { + ws_warning("Error creating output file: %s (%s)", fifo, g_strerror(errno)); + return EXIT_FAILURE; + } + } + + + appname = ws_strdup_printf(SDJOURNAL_EXTCAP_INTERFACE " (Wireshark) %s.%s.%s", + SDJOURNAL_VERSION_MAJOR, SDJOURNAL_VERSION_MINOR, SDJOURNAL_VERSION_RELEASE); + success = pcapng_write_section_header_block(fp, + NULL, /* Comment */ + NULL, /* HW */ + NULL, /* OS */ + appname, + -1, /* section_length */ + &bytes_written, + &err); + g_free(appname); + + if (!success) { + ws_warning("Can't write pcapng file header"); + goto cleanup; + } + + jr = sd_journal_open(&jnl, 0); + if (jr < 0) { + ws_warning("Error opening journal: %s", g_strerror(jr)); + goto cleanup; + } + + jr = sd_id128_get_boot(&boot_id); + if (jr < 0) { + ws_warning("Error fetching system boot ID: %s", g_strerror(jr)); + goto cleanup; + } + + sd_id128_to_string(boot_id, boot_id_str + strlen(FLD_BOOT_ID)); + jr = sd_journal_add_match(jnl, boot_id_str, strlen(boot_id_str)); + if (jr < 0) { + ws_warning("Error adding match: %s", g_strerror(jr)); + goto cleanup; + } + + // According to the documentation, fields *might be* truncated to 64K. + // Let's assume that 2048 is a good balance between fetching entire fields + // and being able to fit as many fields as possible into a packet. + sd_journal_set_data_threshold(jnl, 2048); + + if (start_from_end) { + ws_debug("Attempting to seek %d entries from the end", start_from_entries); + jr = sd_journal_seek_tail(jnl); + if (jr < 0) { + ws_warning("Error starting at end: %s", g_strerror(jr)); + goto cleanup; + } + jr = sd_journal_previous_skip(jnl, (uint64_t) start_from_entries + 1); + if (jr < 0) { + ws_warning("Error skipping backward: %s", g_strerror(jr)); + goto cleanup; + } + } else { + ws_debug("Attempting to seek %d entries from the beginning", start_from_entries); + jr = sd_journal_seek_head(jnl); + if (jr < 0) { + ws_warning("Error starting at beginning: %s", g_strerror(jr)); + goto cleanup; + } + if (start_from_entries > 0) { + jr = sd_journal_next_skip(jnl, (uint64_t) start_from_entries); + if (jr < 0) { + ws_warning("Error skipping forward: %s", g_strerror(jr)); + goto cleanup; + } + } + } + + /* read from channel and write into fp */ + if (sdj_dump_entries(jnl, fp) != 0) { + ws_warning("Error dumping entries"); + goto cleanup; + } + + ret = EXIT_SUCCESS; + +cleanup: + if (jnl) { + sd_journal_close(jnl); + } + + if (err_info) { + ws_warning("%s", err_info); + } + + g_free(err_info); + + /* clean up and exit */ + if (g_strcmp0(fifo, "-")) { + fclose(fp); + } + return ret; +} + +static int list_config(char *interface) +{ + unsigned inc = 0; + + if (!interface) { + ws_warning("ERROR: No interface specified."); + return EXIT_FAILURE; + } + + if (g_strcmp0(interface, SDJOURNAL_EXTCAP_INTERFACE)) { + ws_warning("ERROR: interface must be %s", SDJOURNAL_EXTCAP_INTERFACE); + return EXIT_FAILURE; + } + + printf("arg {number=%u}{call=--start-from}{display=Starting position}" + "{type=string}{tooltip=The journal starting position. Values " + "with a leading \"+\" start from the beginning, similar to the " + "\"tail\" command}{required=false}{group=Journal}\n", inc++); + + extcap_config_debug(&inc); + + return EXIT_SUCCESS; +} + +int main(int argc, char **argv) +{ + char* configuration_init_error; + int result; + int option_idx = 0; + int start_from_entries = 10; + bool start_from_end = true; + int ret = EXIT_FAILURE; + extcap_parameters* extcap_conf = g_new0(extcap_parameters, 1); + char* help_url; + char* help_header = NULL; + + /* Initialize log handler early so we can have proper logging during startup. */ + extcap_log_init("sdjournal"); + + /* + * Get credential information for later use. + */ + init_process_policies(); + + /* + * Attempt to get the pathname of the directory containing the + * executable file. + */ + configuration_init_error = configuration_init(argv[0], NULL); + if (configuration_init_error != NULL) { + ws_warning("Can't get pathname of directory containing the extcap program: %s.", + configuration_init_error); + g_free(configuration_init_error); + } + + help_url = data_file_url("sdjournal.html"); + extcap_base_set_util_info(extcap_conf, argv[0], SDJOURNAL_VERSION_MAJOR, SDJOURNAL_VERSION_MINOR, + SDJOURNAL_VERSION_RELEASE, help_url); + g_free(help_url); + // We don't have an SDJOURNAL DLT, so use USER0 (147). + extcap_base_register_interface(extcap_conf, SDJOURNAL_EXTCAP_INTERFACE, "systemd Journal Export", 147, "USER0"); + + help_header = ws_strdup_printf( + " %s --extcap-interfaces\n" + " %s --extcap-interface=%s --extcap-dlts\n" + " %s --extcap-interface=%s --extcap-config\n" + " %s --extcap-interface=%s --start-from=+0 --fifo=FILENAME --capture\n", + argv[0], + argv[0], SDJOURNAL_EXTCAP_INTERFACE, + argv[0], SDJOURNAL_EXTCAP_INTERFACE, + argv[0], SDJOURNAL_EXTCAP_INTERFACE); + extcap_help_add_header(extcap_conf, help_header); + g_free(help_header); + extcap_help_add_option(extcap_conf, "--help", "print this help"); + extcap_help_add_option(extcap_conf, "--version", "print the version"); + extcap_help_add_option(extcap_conf, "--start-from <entry count>", "starting position"); + + ws_opterr = 0; + ws_optind = 0; + + if (argc == 1) { + extcap_help_print(extcap_conf); + goto end; + } + + while ((result = ws_getopt_long(argc, argv, ":", longopts, &option_idx)) != -1) { + + switch (result) { + + case OPT_HELP: + extcap_help_print(extcap_conf); + ret = EXIT_SUCCESS; + goto end; + + case OPT_VERSION: + extcap_version_print(extcap_conf); + ret = EXIT_SUCCESS; + goto end; + + case OPT_START_FROM: + start_from_entries = (int) strtol(ws_optarg, NULL, 10); + if (errno == EINVAL) { + ws_warning("Invalid entry count: %s", ws_optarg); + goto end; + } + if (strlen(ws_optarg) > 0 && ws_optarg[0] == '+') { + start_from_end = false; + } + if (start_from_entries < 0) { + start_from_end = true; + start_from_entries *= -1; + } + ws_debug("start %d from %s", start_from_entries, start_from_end ? "end" : "beginning"); + break; + + case ':': + /* missing option argument */ + ws_warning("Option '%s' requires an argument", argv[ws_optind - 1]); + break; + + default: + if (!extcap_base_parse_options(extcap_conf, result - EXTCAP_OPT_LIST_INTERFACES, ws_optarg)) { + ws_warning("Invalid option: %s", argv[ws_optind - 1]); + goto end; + } + } + } + + extcap_cmdline_debug(argv, argc); + + if (extcap_base_handle_interface(extcap_conf)) { + ret = EXIT_SUCCESS; + goto end; + } + + if (extcap_conf->show_config) { + ret = list_config(extcap_conf->interface); + goto end; + } + + if (extcap_conf->capture) { + ret = sdj_start_export(start_from_entries, start_from_end, extcap_conf->fifo); + } else { + ws_debug("You should not come here... maybe some parameter missing?"); + ret = EXIT_FAILURE; + } + +end: + /* clean up stuff */ + extcap_base_cleanup(&extcap_conf); + return ret; +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 8 + * tab-width: 8 + * indent-tabs-mode: t + * End: + * + * vi: set shiftwidth=8 tabstop=8 noexpandtab: + * :indentSize=8:tabSize=8:noTabs=false: + */ |