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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 /epan/dissectors/packet-syslog.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 'epan/dissectors/packet-syslog.c')
-rw-r--r-- | epan/dissectors/packet-syslog.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/epan/dissectors/packet-syslog.c b/epan/dissectors/packet-syslog.c new file mode 100644 index 00000000..b8645ffc --- /dev/null +++ b/epan/dissectors/packet-syslog.c @@ -0,0 +1,447 @@ +/* packet-syslog.c + * Routines for syslog message dissection + * + * Copyright 2000, Gerald Combs <gerald[AT]wireshark.org> + * + * Support for passing SS7 MSUs (from the Cisco ITP Packet Logging + * facility) to the MTP3 dissector by Abhik Sarkar <sarkar.abhik[AT]gmail.com> + * with some rework by Jeff Morriss <jeff.morriss.ws [AT] gmail.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald[AT]wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + + +#include <epan/packet.h> +#include <epan/strutil.h> + +#include "packet-syslog.h" +#include "packet-acdr.h" + +#define UDP_PORT_SYSLOG 514 + +#define PRIORITY_MASK 0x0007 /* 0000 0111 */ +#define FACILITY_MASK 0x03f8 /* 1111 1000 */ + +void proto_reg_handoff_syslog(void); +void proto_register_syslog(void); + +/* The maximum number if priority digits to read in. */ +#define MAX_DIGITS 3 + +static const value_string short_level_vals[] = { + { LEVEL_EMERG, "EMERG" }, + { LEVEL_ALERT, "ALERT" }, + { LEVEL_CRIT, "CRIT" }, + { LEVEL_ERR, "ERR" }, + { LEVEL_WARNING, "WARNING" }, + { LEVEL_NOTICE, "NOTICE" }, + { LEVEL_INFO, "INFO" }, + { LEVEL_DEBUG, "DEBUG" }, + { 0, NULL } +}; + +static const value_string short_facility_vals[] = { + { FAC_KERN, "KERN" }, + { FAC_USER, "USER" }, + { FAC_MAIL, "MAIL" }, + { FAC_DAEMON, "DAEMON" }, + { FAC_AUTH, "AUTH" }, + { FAC_SYSLOG, "SYSLOG" }, + { FAC_LPR, "LPR" }, + { FAC_NEWS, "NEWS" }, + { FAC_UUCP, "UUCP" }, + { FAC_CRON, "CRON" }, /* The BSDs, Linux, and others */ + { FAC_AUTHPRIV, "AUTHPRIV" }, + { FAC_FTP, "FTP" }, + { FAC_NTP, "NTP" }, + { FAC_LOGAUDIT, "LOGAUDIT" }, + { FAC_LOGALERT, "LOGALERT" }, + { FAC_CRON_SOL, "CRON" }, /* Solaris */ + { FAC_LOCAL0, "LOCAL0" }, + { FAC_LOCAL1, "LOCAL1" }, + { FAC_LOCAL2, "LOCAL2" }, + { FAC_LOCAL3, "LOCAL3" }, + { FAC_LOCAL4, "LOCAL4" }, + { FAC_LOCAL5, "LOCAL5" }, + { FAC_LOCAL6, "LOCAL6" }, + { FAC_LOCAL7, "LOCAL7" }, + { 0, NULL } +}; + +static gint proto_syslog = -1; +static gint hf_syslog_level = -1; +static gint hf_syslog_facility = -1; +static gint hf_syslog_msg = -1; +static gint hf_syslog_msu_present = -1; +static gint hf_syslog_version = -1; +static gint hf_syslog_timestamp = -1; +static gint hf_syslog_timestamp_old = -1; +static gint hf_syslog_hostname = -1; +static gint hf_syslog_appname = -1; +static gint hf_syslog_procid = -1; +static gint hf_syslog_msgid = -1; +static gint hf_syslog_msgid_utf8 = -1; +static gint hf_syslog_msgid_bom = -1; + +static gint ett_syslog = -1; +static gint ett_syslog_msg = -1; + +static dissector_handle_t syslog_handle; + +static dissector_handle_t mtp_handle; + +/* The Cisco ITP's packet logging facility allows selected (SS7) MSUs to be + * to be encapsulated in syslog UDP datagrams and sent to a monitoring tool. + * However, no actual tool to monitor/decode the MSUs is provided. The aim + * of this routine is to extract the hex dump of the MSU from the syslog + * packet so that it can be passed on to the mtp3 dissector for decoding. + */ +static tvbuff_t * +mtp3_msu_present(tvbuff_t *tvb, packet_info *pinfo, gint fac, gint level, const char *msg_str, gint chars_truncated) +{ + size_t nbytes; + size_t len; + gchar **split_string, *msu_hex_dump; + tvbuff_t *mtp3_tvb = NULL; + guint8 *byte_array; + + /* In the sample capture I have, all MSUs are LOCAL0.DEBUG. + * Try to optimize this routine for most syslog users by short-cutting + * out here. + */ + if (!(fac == FAC_LOCAL0 && level == LEVEL_DEBUG)) + return NULL; + + if (strstr(msg_str, "msu=") == NULL) + return NULL; + + split_string = g_strsplit(msg_str, "msu=", 2); + msu_hex_dump = split_string[1]; + + if (msu_hex_dump && (len = strlen(msu_hex_dump))) { + + /* convert_string_to_hex() will return NULL if it gets an incomplete + * byte. If we have an odd string length then chop off the remaining + * nibble so we can get at least a partial MSU (chances are the + * subdissector will except out, of course). + */ + if (len % 2) + msu_hex_dump[len - 1] = '\0'; + + byte_array = convert_string_to_hex(msu_hex_dump, &nbytes); + + if (byte_array) { + mtp3_tvb = tvb_new_child_real_data(tvb, byte_array, (guint)nbytes, + (guint)nbytes + chars_truncated / 2); + tvb_set_free_cb(mtp3_tvb, g_free); + /* ...and add the encapsulated MSU as a new data source so that it gets + * its own tab in the packet bytes pane. + */ + add_new_data_source(pinfo, mtp3_tvb, "Encapsulated MSU"); + } + } + + g_strfreev(split_string); + + return(mtp3_tvb); +} + +static gboolean dissect_syslog_info(proto_tree* tree, tvbuff_t* tvb, guint* offset, gint hfindex) +{ + gint end_offset = tvb_find_guint8(tvb, *offset, -1, ' '); + if (end_offset == -1) + return FALSE; + proto_tree_add_item(tree, hfindex, tvb, *offset, end_offset - *offset, ENC_NA); + *offset = end_offset + 1; + return TRUE; +} + +/* Dissect message as defined in RFC5424 */ +static void +dissect_syslog_message(proto_tree* tree, tvbuff_t* tvb, guint offset) +{ + gint end_offset; + + if (!dissect_syslog_info(tree, tvb, &offset, hf_syslog_version)) + return; + + end_offset = tvb_find_guint8(tvb, offset, -1, ' '); + if (end_offset == -1) + return; + if ((guint)end_offset != offset) { + /* do not call proto_tree_add_time_item with a length of 0 */ + proto_tree_add_time_item(tree, hf_syslog_timestamp, tvb, offset, end_offset - offset, ENC_ISO_8601_DATE_TIME, + NULL, NULL, NULL); + } + offset = end_offset + 1; + + if (!dissect_syslog_info(tree, tvb, &offset, hf_syslog_hostname)) + return; + if (!dissect_syslog_info(tree, tvb, &offset, hf_syslog_appname)) + return; + if (!dissect_syslog_info(tree, tvb, &offset, hf_syslog_procid)) + return; + if (tvb_get_guint24(tvb, offset, ENC_BIG_ENDIAN) == 0xefbbbf) { + proto_tree_add_item(tree, hf_syslog_msgid_bom, tvb, offset, 3, ENC_BIG_ENDIAN); + offset += 3; + proto_tree_add_item(tree, hf_syslog_msgid_utf8, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_UTF_8); + } else { + proto_tree_add_item(tree, hf_syslog_msgid, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_ASCII); + } +} + +/* Dissect message as defined in RFC3164 */ +static void +dissect_rfc3164_syslog_message(proto_tree* tree, tvbuff_t* tvb, guint offset) +{ + guint tvb_offset = 0; + + /* Simple check if the first 16 bytes look like TIMESTAMP "Mmm dd hh:mm:ss" + * by checking for spaces and colons. Otherwise return without processing + * the message. */ + if (tvb_get_guint8(tvb, offset + 3) == ' ' && tvb_get_guint8(tvb, offset + 6) == ' ' && + tvb_get_guint8(tvb, offset + 9) == ':' && tvb_get_guint8(tvb, offset + 12) == ':' && + tvb_get_guint8(tvb, offset + 15) == ' ') { + proto_tree_add_item(tree, hf_syslog_timestamp_old, tvb, offset, 15, ENC_ASCII); + offset += 16; + } else { + return; + } + + if (!dissect_syslog_info(tree, tvb, &offset, hf_syslog_hostname)) + return; + for (tvb_offset=offset; tvb_offset < offset+32; tvb_offset++){ + guint8 octet; + octet = tvb_get_guint8(tvb, tvb_offset); + if (!g_ascii_isalnum(octet)){ + proto_tree_add_item(tree, hf_syslog_procid, tvb, offset, tvb_offset - offset, ENC_ASCII); + offset = tvb_offset; + break; + } + } + proto_tree_add_item(tree, hf_syslog_msgid, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_ASCII); +} + +/* The message format is defined in RFC 3164 */ +static int +dissect_syslog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + gint pri = -1, lev = -1, fac = -1; + gint msg_off = 0, msg_len, reported_msg_len; + proto_item *ti; + proto_tree *syslog_tree; + proto_tree *syslog_message_tree; + const char *msg_str; + tvbuff_t *mtp3_tvb; + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "Syslog"); + col_clear(pinfo->cinfo, COL_INFO); + + if (tvb_get_guint8(tvb, msg_off) == '<') { + /* A facility and level follow. */ + msg_off++; + pri = 0; + while (tvb_bytes_exist(tvb, msg_off, 1) && + g_ascii_isdigit(tvb_get_guint8(tvb, msg_off)) && msg_off <= MAX_DIGITS) { + pri = pri * 10 + (tvb_get_guint8(tvb, msg_off) - '0'); + msg_off++; + } + if (tvb_get_guint8(tvb, msg_off) == '>') + msg_off++; + fac = (pri & FACILITY_MASK) >> 3; + lev = pri & PRIORITY_MASK; + } + + msg_len = tvb_ensure_captured_length_remaining(tvb, msg_off); + msg_str = tvb_format_text(pinfo->pool, tvb, msg_off, msg_len); + reported_msg_len = tvb_reported_length_remaining(tvb, msg_off); + + mtp3_tvb = mtp3_msu_present(tvb, pinfo, fac, lev, msg_str, + (reported_msg_len - msg_len)); + + if (mtp3_tvb == NULL) { + if (pri >= 0) { + col_add_fstr(pinfo->cinfo, COL_INFO, "%s.%s: %s", + val_to_str_const(fac, short_facility_vals, "UNKNOWN"), + val_to_str_const(lev, short_level_vals, "UNKNOWN"), msg_str); + } else { + col_add_str(pinfo->cinfo, COL_INFO, msg_str); + } + } + + if (tree) { + if (pri >= 0) { + ti = proto_tree_add_protocol_format(tree, proto_syslog, tvb, 0, -1, + "Syslog message: %s.%s: %s", + val_to_str_const(fac, short_facility_vals, "UNKNOWN"), + val_to_str_const(lev, short_level_vals, "UNKNOWN"), msg_str); + } else { + ti = proto_tree_add_protocol_format(tree, proto_syslog, tvb, 0, -1, + "Syslog message: (unknown): %s", msg_str); + } + syslog_tree = proto_item_add_subtree(ti, ett_syslog); + if (pri >= 0) { + proto_tree_add_uint(syslog_tree, hf_syslog_facility, tvb, 0, + msg_off, pri); + proto_tree_add_uint(syslog_tree, hf_syslog_level, tvb, 0, + msg_off, pri); + } + ti = proto_tree_add_item(syslog_tree, hf_syslog_msg, tvb, msg_off, + msg_len, ENC_UTF_8); + syslog_message_tree = proto_item_add_subtree(ti, ett_syslog_msg); + + /* RFC5424 defines a version field which is currently defined as '1' + * followed by a space (0x3120). Otherwise the message is probable + * a RFC3164 message. + */ + if (msg_len > 2 && tvb_get_ntohs(tvb, msg_off) == 0x3120) { + dissect_syslog_message(syslog_message_tree, tvb, msg_off); + } else if ( msg_len > 15) { + dissect_rfc3164_syslog_message(syslog_message_tree, tvb, msg_off); + } + + if (mtp3_tvb) { + proto_item *mtp3_item; + mtp3_item = proto_tree_add_boolean(syslog_tree, hf_syslog_msu_present, + tvb, msg_off, msg_len, TRUE); + proto_item_set_generated(mtp3_item); + } + } + + /* Call MTP dissector if encapsulated MSU was found... */ + if (mtp3_tvb) { + call_dissector(mtp_handle, mtp3_tvb, pinfo, tree); + } + + return tvb_captured_length(tvb); +} + +/* Register the protocol with Wireshark */ +void proto_register_syslog(void) +{ + + /* Setup list of header fields */ + static hf_register_info hf[] = { + { &hf_syslog_facility, + { "Facility", "syslog.facility", + FT_UINT8, BASE_DEC, VALS(syslog_facility_vals), FACILITY_MASK, + "Message facility", HFILL } + }, + { &hf_syslog_level, + { "Level", "syslog.level", + FT_UINT8, BASE_DEC, VALS(syslog_level_vals), PRIORITY_MASK, + "Message level", HFILL } + }, + { &hf_syslog_msg, + { "Message", "syslog.msg", + FT_STRING, BASE_NONE, NULL, 0x0, + "Message Text", HFILL } + }, + { &hf_syslog_msu_present, + { "SS7 MSU present", "syslog.msu_present", + FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "True if an SS7 MSU was detected in the syslog message", + HFILL } + }, + { &hf_syslog_version, + { "Syslog version", "syslog.version", + FT_STRING, BASE_NONE, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_timestamp, + { "Syslog timestamp", "syslog.timestamp", + FT_ABSOLUTE_TIME, ABSOLUTE_TIME_UTC, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_timestamp_old, + { "Syslog timestamp (RFC3164)", "syslog.timestamp_rfc3164", + FT_STRING, ENC_ASCII, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_hostname, + { "Syslog hostname", "syslog.hostname", + FT_STRING, ENC_ASCII, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_appname, + { "Syslog app name", "syslog.appname", + FT_STRING, ENC_ASCII, NULL, 0x0, + "The name of the app that generated this message", + HFILL } + }, + { &hf_syslog_procid, + { "Syslog process id", "syslog.procid", + FT_STRING, ENC_ASCII, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_msgid, + { "Syslog message id", "syslog.msgid", + FT_STRING, ENC_ASCII, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_msgid_utf8, + { "Syslog message id", "syslog.msgid", + FT_STRING, BASE_NONE, NULL, 0x0, + NULL, + HFILL } + }, + { &hf_syslog_msgid_bom, + { "Syslog BOM", "syslog.msgid.bom", + FT_UINT24, BASE_HEX, NULL, 0x0, + NULL, + HFILL } + } + }; + + /* Setup protocol subtree array */ + static gint *ett[] = { + &ett_syslog, + &ett_syslog_msg + }; + + /* Register the protocol name and description */ + proto_syslog = proto_register_protocol("Syslog message", "Syslog", "syslog"); + + /* Required function calls to register the header fields and subtrees used */ + proto_register_field_array(proto_syslog, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + syslog_handle = register_dissector("syslog", dissect_syslog, proto_syslog); +} + +void +proto_reg_handoff_syslog(void) +{ + dissector_add_uint_with_preference("udp.port", UDP_PORT_SYSLOG, syslog_handle); + dissector_add_for_decode_as_with_preference("tcp.port", syslog_handle); + + dissector_add_uint("acdr.media_type", ACDR_Info, syslog_handle); + + /* Find the mtp3 dissector */ + mtp_handle = find_dissector_add_dependency("mtp3", proto_syslog); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local Variables: + * c-basic-offset: 2 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * ex: set shiftwidth=2 tabstop=8 expandtab: + * :indentSize=2:tabSize=8:noTabs=true: + */ |