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suricata/src/detect-seq.c

316 lines
8.2 KiB
C

16 years ago
/* Copyright (c) 2009 Open Information Security Foundation */
/**
* \file
* \author Brian Rectanus <brectanu@gmail.com>
*
* Implements the "seq" keyword.
*/
#include "suricata-common.h"
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#include "debug.h"
#include "decode.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-seq.h"
#include "util-byte.h"
#include "util-unittest.h"
static int DetectSeqSetup(DetectEngineCtx *, Signature *s, SigMatch *m,
char *sidstr);
static int DetectSeqMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m);
static void DetectSeqRegisterTests(void);
static void DetectSeqFree(void *ptr);
void DetectSeqRegister(void) {
sigmatch_table[DETECT_SEQ].name = "seq";
sigmatch_table[DETECT_SEQ].Match = DetectSeqMatch;
sigmatch_table[DETECT_SEQ].Setup = DetectSeqSetup;
sigmatch_table[DETECT_SEQ].Free = DetectSeqFree;
sigmatch_table[DETECT_SEQ].RegisterTests = DetectSeqRegisterTests;
}
/**
* \internal
* \brief This function is used to match packets with a given Seq number
*
* \param t pointer to thread vars
* \param det_ctx pointer to the pattern matcher thread
* \param p pointer to the current packet
* \param m pointer to the sigmatch that we will cast into DetectSeqData
*
* \retval 0 no match
* \retval 1 match
*/
static int DetectSeqMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m)
{
DetectSeqData *data = (DetectSeqData *)m->ctx;
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/* This is only needed on TCP packets */
if (IPPROTO_TCP != p->proto) {
return 0;
}
return (data->seq == TCP_GET_SEQ(p)) ? 1 : 0;
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}
/**
* \internal
* \brief this function is used to add the seq option into the signature
*
* \param de_ctx pointer to the Detection Engine Context
* \param s pointer to the Current Signature
* \param m pointer to the Current SigMatch
* \param optstr pointer to the user provided options
*
* \retval 0 on Success
* \retval -1 on Failure
*/
static int DetectSeqSetup (DetectEngineCtx *de_ctx, Signature *s,
SigMatch *m, char *optstr)
{
DetectSeqData *data = malloc(sizeof(DetectSeqData));
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SigMatch *sm = NULL;
//printf("DetectSeqSetup: \'%s\'\n", optstr);
data = malloc(sizeof(DetectSeqData));
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if (data == NULL) {
printf("DetectSeqSetup: malloc failed\n");
goto error;
}
sm = SigMatchAlloc();
if (sm == NULL) {
goto error;
}
sm->type = DETECT_SEQ;
if (-1 == ByteExtractStringUint32(&data->seq, 10, 0, optstr)) {
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goto error;
}
sm->ctx = data;
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SigMatchAppend(s, m, sm);
return 0;
error:
if (data) free(data);
return -1;
}
/**
* \internal
* \brief this function will free memory associated with seq option
*
* \param data pointer to seq configuration data
*/
static void DetectSeqFree(void *ptr)
{
DetectSeqData *data = (DetectSeqData *)ptr;
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free(data);
}
#ifdef UNITTESTS
/**
* \internal
* \brief This test tests sameip success and failure.
*/
static int DetectSeqSigTest01Real(int mpm_type)
{
uint8_t *buf = (uint8_t *)"";
uint16_t buflen = strlen((char *)buf);
Packet p[3];
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx;
int result = 0;
uint8_t tcp_hdr0[] = {
0x00, 0x50, 0x8e, 0x16, 0x0d, 0x59, 0xcd, 0x3c,
0xcf, 0x0d, 0x21, 0x80, 0xa0, 0x12, 0x16, 0xa0,
0xfa, 0x03, 0x00, 0x00, 0x02, 0x04, 0x05, 0xb4,
0x04, 0x02, 0x08, 0x0a, 0x6e, 0x18, 0x78, 0x73,
0x01, 0x71, 0x74, 0xde, 0x01, 0x03, 0x03, 0x02
};
uint8_t tcp_hdr1[] = {
0x00, 0x50, 0x8e, 0x16, 0x0d, 0x59, 0xcd, 0x3c,
0xcf, 0x0d, 0x21, 0x80, 0xa0, 0x12, 0x16, 0xa0,
0xfa, 0x03, 0x00, 0x00, 0x02, 0x04, 0x05, 0xb4,
0x04, 0x02, 0x08, 0x0a, 0x6e, 0x18, 0x78, 0x73,
0x01, 0x71, 0x74, 0xde, 0x01, 0x03, 0x03, 0x02
};
memset(&th_v, 0, sizeof(th_v));
/* TCP w/seq=42 */
memset(&p[0], 0, sizeof(p[0]));
p[0].src.family = AF_INET;
p[0].dst.family = AF_INET;
p[0].payload = buf;
p[0].payload_len = buflen;
p[0].proto = IPPROTO_TCP;
p[0].tcph = (TCPHdr *)tcp_hdr0;
p[0].tcph->th_seq = htonl(42);
/* TCP w/seq=100 */
memset(&p[1], 0, sizeof(p[1]));
p[1].src.family = AF_INET;
p[1].dst.family = AF_INET;
p[1].payload = buf;
p[1].payload_len = buflen;
p[1].proto = IPPROTO_TCP;
p[1].tcph = (TCPHdr *)tcp_hdr1;
p[1].tcph->th_seq = htonl(100);
/* ICMP */
memset(&p[2], 0, sizeof(p[2]));
p[2].src.family = AF_INET;
p[2].dst.family = AF_INET;
p[2].payload = buf;
p[2].payload_len = buflen;
p[2].proto = IPPROTO_ICMP;
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL) {
goto end;
}
de_ctx->mpm_matcher = mpm_type;
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de_ctx->flags |= DE_QUIET;
/* These three are crammed in here as there is no Parse */
if (SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing seq\";seq:foo;sid:1;)") != NULL)
{
printf("invalid seq accepted: ");
goto cleanup_engine;
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}
if (SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing seq\";seq:9999999999;sid:1;)") != NULL)
{
printf("overflowing seq accepted: ");
goto cleanup_engine;
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}
if (SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing seq\";seq:-100;sid:1;)") != NULL)
{
printf("negative seq accepted: ");
goto cleanup_engine;
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}
de_ctx->sig_list = SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing seq\";seq:41;sid:1;)");
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if (de_ctx->sig_list == NULL) {
goto cleanup_engine;
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}
de_ctx->sig_list->next = SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing seq\";seq:42;sid:2;)");
if (de_ctx->sig_list->next == NULL) {
goto cleanup_engine;
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}
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
SigMatchSignatures(&th_v, de_ctx, det_ctx, &p[0]);
if (PacketAlertCheck(&p[0], 1) != 0) {
printf("sid 1 alerted, but should not have: ");
goto cleanup;
}
if (PacketAlertCheck(&p[0], 2) == 0) {
printf("sid 2 did not alert, but should have: ");
goto cleanup;
}
SigMatchSignatures(&th_v, de_ctx, det_ctx, &p[1]);
if (PacketAlertCheck(&p[1], 1) != 0) {
printf("sid 1 alerted, but should not have: ");
goto cleanup;
}
if (PacketAlertCheck(&p[1], 2) != 0) {
printf("sid 2 alerted, but should not have: ");
goto cleanup;
}
SigMatchSignatures(&th_v, de_ctx, det_ctx, &p[1]);
if (PacketAlertCheck(&p[2], 1) != 0) {
printf("sid 1 alerted, but should not have: ");
goto cleanup;
}
if (PacketAlertCheck(&p[2], 2) != 0) {
printf("sid 2 alerted, but should not have: ");
goto cleanup;
}
result = 1;
cleanup:
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
cleanup_engine:
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DetectEngineCtxFree(de_ctx);
end:
return result;
}
/**
* \test DetectSeqSigTest01B2g tests sameip under B2g MPM
*/
static int DetectSeqSigTest01B2g(void)
{
return DetectSeqSigTest01Real(MPM_B2G);
}
/**
* \test DetectSeqSigTest01B2g tests sameip under B3g MPM
*/
static int DetectSeqSigTest01B3g(void)
{
return DetectSeqSigTest01Real(MPM_B3G);
}
/**
* \test DetectSeqSigTest01B2g tests sameip under WuManber MPM
*/
static int DetectSeqSigTest01Wm(void)
{
return DetectSeqSigTest01Real(MPM_WUMANBER);
}
#endif /* UNITTESTS */
/**
* \internal
* \brief This function registers unit tests for DetectSeq
*/
static void DetectSeqRegisterTests(void)
{
#ifdef UNITTESTS
UtRegisterTest("DetectSeqSigTest01B2g", DetectSeqSigTest01B2g, 1);
UtRegisterTest("DetectSeqSigTest01B3g", DetectSeqSigTest01B3g, 1);
UtRegisterTest("DetectSeqSigTest01Wm", DetectSeqSigTest01Wm, 1);
#endif /* UNITTESTS */
}