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/*
* syslog.c
*
* Copyright (C) 2009-11 - ipoque GmbH
* Copyright (C) 2011-22 - ntop.org
*
* This file is part of nDPI, an open source deep packet inspection
* library based on the OpenDPI and PACE technology by ipoque GmbH
*
* nDPI is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* nDPI is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with nDPI. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "ndpi_protocol_ids.h"
#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_SYSLOG
#include "ndpi_api.h"
static void ndpi_int_syslog_add_connection(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_SYSLOG, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
}
void ndpi_search_syslog(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &ndpi_struct->packet;
u_int8_t i;
NDPI_LOG_DBG(ndpi_struct, "search syslog\n");
if (packet->payload_packet_len > 20 && packet->payload[0] == '<') {
int j;
NDPI_LOG_DBG2(ndpi_struct, "checked len>20 and <1024 and first symbol=<\n");
for (i = 1; i <= 3; i++) {
if (packet->payload[i] < '0' || packet->payload[i] > '9') {
break;
}
}
NDPI_LOG_DBG2(ndpi_struct,
"read symbols while the symbol is a number.\n");
if (packet->payload[i++] != '>') {
NDPI_LOG_DBG(ndpi_struct, "excluded, there is no > following the number\n");
NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
return;
} else {
NDPI_LOG_DBG2(ndpi_struct, "a > following the number\n");
}
if (packet->payload[i] == 0x20) {
NDPI_LOG_DBG2(ndpi_struct, "a blank following the >: increment i\n");
i++;
} else {
NDPI_LOG_DBG2(ndpi_struct, "no blank following the >: do nothing\n");
}
/* Even if there are 2 RFCs (3164, 5424), syslog format after "<NUMBER>" is
not standard. The only common pattern seems to be that the entire
payload is made by printable characters */
/* TODO: check only the first N bytes to avoid touching the entire payload? */
for (j = 0; j < packet->payload_packet_len - i; j++) {
if (!(ndpi_isprint(packet->payload[i + j]) ||
ndpi_isspace(packet->payload[i + j]))) {
NDPI_LOG_DBG2(ndpi_struct, "no printable char 0x%x [i/j %d/%d]\n",
packet->payload[i + j], i, j);
NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
return;
}
}
NDPI_LOG_INFO(ndpi_struct, "found syslog\n");
ndpi_int_syslog_add_connection(ndpi_struct, flow);
return;
}
NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
}
void init_syslog_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
ndpi_set_bitmask_protocol_detection("Syslog", ndpi_struct, detection_bitmask, *id,
NDPI_PROTOCOL_SYSLOG,
ndpi_search_syslog,
NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
SAVE_DETECTION_BITMASK_AS_UNKNOWN,
ADD_TO_DETECTION_BITMASK);
*id += 1;
}
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