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suricata/examples/lib/custom/main.c

263 lines
7.5 KiB
C

/* Copyright (C) 2024 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include "suricata.h"
#include "detect.h"
#include "detect-engine.h"
#include "runmodes.h"
#include "conf.h"
#include "pcap.h"
#include "runmode-lib.h"
#include "tm-threads.h"
#include "threadvars.h"
#include "action-globals.h"
#include "packet.h"
#include "util-device.h"
static int worker_id = 1;
/**
* Struct to pass arguments into a worker thread.
*/
struct WorkerArgs {
ThreadVars *tv;
char *pcap_filename;
};
/**
* Release packet callback.
*
* If there is any cleanup that needs to be done when Suricata is done
* with a packet, this is the place to do it.
*
* Important: If using a custom release function, you must also
* release or free the packet.
*
* Optionally this is where you would handle IPS like functionality
* such as forwarding the packet, or triggering some other mechanism
* to forward the packet.
*/
static void ReleasePacket(Packet *p)
{
if (PacketCheckAction(p, ACTION_DROP)) {
SCLogNotice("Dropping packet!");
}
/* As we overode the default release function, we must release or
* free the packet. */
PacketFreeOrRelease(p);
}
/**
* Suricata worker thread in library mode.
* The functions should be wrapped in an API layer.
*/
static void *SimpleWorker(void *arg)
{
struct WorkerArgs *args = arg;
ThreadVars *tv = args->tv;
/* Start worker. */
if (SCRunModeLibSpawnWorker(tv) != 0) {
pthread_exit(NULL);
}
/* Replay pcap. */
pcap_t *fp = pcap_open_offline(args->pcap_filename, NULL);
if (fp == NULL) {
pthread_exit(NULL);
}
LiveDevice *device = LiveGetDevice("lib0");
assert(device != NULL);
int datalink = pcap_datalink(fp);
int count = 0;
struct pcap_pkthdr pkthdr;
const u_char *packet;
while ((packet = pcap_next(fp, &pkthdr)) != NULL) {
/* Have we been asked to stop? */
if (suricata_ctl_flags & SURICATA_STOP) {
goto done;
}
Packet *p = PacketGetFromQueueOrAlloc();
if (unlikely(p == NULL)) {
/* Memory allocation error. */
goto done;
}
/* If we are processing a PCAP and it is the first packet we need to set the timestamp. */
SCTime_t timestamp = SCTIME_FROM_TIMEVAL(&pkthdr.ts);
if (count == 0) {
TmThreadsInitThreadsTimestamp(timestamp);
}
/* Setup the packet, these will become functions to avoid
* internal Packet access. */
SCPacketSetSource(p, PKT_SRC_WIRE);
SCPacketSetTime(p, SCTIME_FROM_TIMEVAL(&pkthdr.ts));
SCPacketSetDatalink(p, datalink);
SCPacketSetLiveDevice(p, device);
SCPacketSetReleasePacket(p, ReleasePacket);
if (PacketSetData(p, packet, pkthdr.len) == -1) {
TmqhOutputPacketpool(tv, p);
goto done;
}
if (TmThreadsSlotProcessPkt(tv, tv->tm_slots, p) != TM_ECODE_OK) {
TmqhOutputPacketpool(tv, p);
goto done;
}
LiveDevicePktsIncr(device);
count++;
}
done:
pcap_close(fp);
/* Stop the engine. */
EngineStop();
/* Cleanup.
*
* Note that there is some thread synchronization between this
* function and SuricataShutdown such that they must be run
* concurrently at this time before either will exit. */
SCTmThreadsSlotPacketLoopFinish(tv);
SCLogNotice("Worker thread exiting");
pthread_exit(NULL);
}
static uint8_t RateFilterCallback(const Packet *p, const uint32_t sid, const uint32_t gid,
const uint32_t rev, uint8_t original_action, uint8_t new_action, void *arg)
{
/* Don't change the action. */
return new_action;
}
int main(int argc, char **argv)
{
SuricataPreInit(argv[0]);
/* Parse command line options. This is optional, you could
* directly configure Suricata through the Conf API. */
SCParseCommandLine(argc, argv);
/* Find our list of pcap files, after the "--". */
while (argc) {
bool end = strncmp(argv[0], "--", 2) == 0;
argv++;
argc--;
if (end) {
break;
}
}
if (argc == 0) {
fprintf(stderr, "ERROR: No PCAP files provided\n");
return 1;
}
/* Set the runmode to library mode. Perhaps in the future this
* should be done in some library bootstrap function. */
SCRunmodeSet(RUNMODE_LIB);
/* Validate/finalize the runmode. */
if (SCFinalizeRunMode() != TM_ECODE_OK) {
exit(EXIT_FAILURE);
}
/* Handle internal runmodes. Typically you wouldn't do this as a
* library user, however this example is showing how to replicate
* the Suricata application with the library. */
switch (SCStartInternalRunMode(argc, argv)) {
case TM_ECODE_DONE:
exit(EXIT_SUCCESS);
case TM_ECODE_FAILED:
exit(EXIT_FAILURE);
}
/* Load configuration file, could be done earlier but must be done
* before SuricataInit, but even then its still optional as you
* may be programmatically configuration Suricata. */
if (SCLoadYamlConfig() != TM_ECODE_OK) {
exit(EXIT_FAILURE);
}
/* Enable default signal handlers including SIGHUP for log file rotation,
* and SIGUSR2 for reloading rules. This should be done with care by a
* library user as the application may already have signal handlers
* loaded. */
SCEnableDefaultSignalHandlers();
/* Set "offline" runmode to replay a pcap in library mode. */
if (!SCConfSetFromString("runmode=offline", 1)) {
exit(EXIT_FAILURE);
}
/* Force logging to the current directory. */
SCConfSetFromString("default-log-dir=.", 1);
if (LiveRegisterDevice("lib0") < 0) {
fprintf(stderr, "LiveRegisterDevice failed");
exit(1);
}
SuricataInit();
SCDetectEngineRegisterRateFilterCallback(RateFilterCallback, NULL);
/* Create and start worker on its own thread, passing the PCAP
* file as argument. This needs to be done in between SuricataInit
* and SuricataPostInit. */
pthread_t worker;
ThreadVars *tv = SCRunModeLibCreateThreadVars(worker_id++);
if (!tv) {
FatalError("Failed to create ThreadVars");
}
struct WorkerArgs args = {
.tv = tv,
.pcap_filename = argv[argc - 1],
};
if (pthread_create(&worker, NULL, SimpleWorker, &args) != 0) {
exit(EXIT_FAILURE);
}
SuricataPostInit();
/* Run the main loop, this just waits for the worker thread to
* call EngineStop signalling Suricata that it is done reading the
* pcap. */
SuricataMainLoop();
/* Shutdown engine. */
SCLogNotice("Shutting down");
/* Note that there is some thread synchronization between this
* function and SCTmThreadsSlotPacketLoopFinish that require them
* to be run concurrently at this time. */
SuricataShutdown();
GlobalsDestroy();
return EXIT_SUCCESS;
}