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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:39:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:39:49 +0000 |
commit | a0aa2307322cd47bbf416810ac0292925e03be87 (patch) | |
tree | 37076262a026c4b48c8a0e84f44ff9187556ca35 /src/detect-stream_size.c | |
parent | Initial commit. (diff) | |
download | suricata-a0aa2307322cd47bbf416810ac0292925e03be87.tar.xz suricata-a0aa2307322cd47bbf416810ac0292925e03be87.zip |
Adding upstream version 1:7.0.3.upstream/1%7.0.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/detect-stream_size.c')
-rw-r--r-- | src/detect-stream_size.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/src/detect-stream_size.c b/src/detect-stream_size.c new file mode 100644 index 0000000..50cd15a --- /dev/null +++ b/src/detect-stream_size.c @@ -0,0 +1,419 @@ +/* Copyright (C) 2007-2020 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. + */ + +/** + * \file + * + * \author Gurvinder Singh <gurvindersinghdahiya@gmail.com> + * + * Stream size for the engine. + */ + +#include "suricata-common.h" +#include "stream-tcp.h" +#include "util-unittest.h" + +#include "detect.h" +#include "detect-parse.h" + +#include "flow.h" +#include "detect-stream_size.h" +#include "stream-tcp-private.h" +#include "detect-engine-prefilter-common.h" +#include "detect-engine-uint.h" +#include "util-debug.h" +#include "util-byte.h" + + +/*prototypes*/ +static int DetectStreamSizeMatch (DetectEngineThreadCtx *, Packet *, + const Signature *, const SigMatchCtx *); +static int DetectStreamSizeSetup (DetectEngineCtx *, Signature *, const char *); +void DetectStreamSizeFree(DetectEngineCtx *de_ctx, void *); +#ifdef UNITTESTS +static void DetectStreamSizeRegisterTests(void); +#endif +static int PrefilterSetupStreamSize(DetectEngineCtx *de_ctx, SigGroupHead *sgh); +static bool PrefilterStreamSizeIsPrefilterable(const Signature *s); + +/** + * \brief Registration function for stream_size: keyword + */ + +void DetectStreamSizeRegister(void) +{ + sigmatch_table[DETECT_STREAM_SIZE].name = "stream_size"; + sigmatch_table[DETECT_STREAM_SIZE].desc = "match on amount of bytes of a stream"; + sigmatch_table[DETECT_STREAM_SIZE].url = "/rules/flow-keywords.html#stream-size"; + sigmatch_table[DETECT_STREAM_SIZE].Match = DetectStreamSizeMatch; + sigmatch_table[DETECT_STREAM_SIZE].Setup = DetectStreamSizeSetup; + sigmatch_table[DETECT_STREAM_SIZE].Free = DetectStreamSizeFree; +#ifdef UNITTESTS + sigmatch_table[DETECT_STREAM_SIZE].RegisterTests = DetectStreamSizeRegisterTests; +#endif + sigmatch_table[DETECT_STREAM_SIZE].SupportsPrefilter = PrefilterStreamSizeIsPrefilterable; + sigmatch_table[DETECT_STREAM_SIZE].SetupPrefilter = PrefilterSetupStreamSize; +} + +static int DetectStreamSizeMatchAux(const DetectStreamSizeData *sd, const TcpSession *ssn) +{ + int ret = 0; + uint32_t csdiff = 0; + uint32_t ssdiff = 0; + + if (sd->flags == StreamSizeServer) { + /* get the server stream size */ + ssdiff = ssn->server.next_seq - ssn->server.isn; + ret = DetectU32Match(ssdiff, &sd->du32); + + } else if (sd->flags == StreamSizeClient) { + /* get the client stream size */ + csdiff = ssn->client.next_seq - ssn->client.isn; + ret = DetectU32Match(csdiff, &sd->du32); + + } else if (sd->flags == StreamSizeBoth) { + ssdiff = ssn->server.next_seq - ssn->server.isn; + csdiff = ssn->client.next_seq - ssn->client.isn; + + if (DetectU32Match(ssdiff, &sd->du32) && DetectU32Match(csdiff, &sd->du32)) + ret = 1; + + } else if (sd->flags == StreamSizeEither) { + ssdiff = ssn->server.next_seq - ssn->server.isn; + csdiff = ssn->client.next_seq - ssn->client.isn; + + if (DetectU32Match(ssdiff, &sd->du32) || DetectU32Match(csdiff, &sd->du32)) + ret = 1; + } + return ret; +} + +/** + * \brief This function is used to match Stream size rule option on a packet with those passed via + * stream_size: + * + * \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 DetectStreamSizeData + * + * \retval 0 no match + * \retval 1 match + */ +static int DetectStreamSizeMatch( + DetectEngineThreadCtx *det_ctx, Packet *p, const Signature *s, const SigMatchCtx *ctx) +{ + + const DetectStreamSizeData *sd = (const DetectStreamSizeData *)ctx; + + if (!(PKT_IS_TCP(p))) + return 0; + if (p->flow == NULL || p->flow->protoctx == NULL) + return 0; + + const TcpSession *ssn = (TcpSession *)p->flow->protoctx; + + SCReturnInt(DetectStreamSizeMatchAux(sd, ssn)); +} + +/** + * \brief this function is used to add the parsed stream size data into the current signature + * + * \param de_ctx pointer to the Detection Engine Context + * \param s pointer to the Current Signature + * \param streamstr pointer to the user provided stream size options + * + * \retval 0 on Success + * \retval -1 on Failure + */ +static int DetectStreamSizeSetup (DetectEngineCtx *de_ctx, Signature *s, const char *streamstr) +{ + DetectStreamSizeData *sd = rs_detect_stream_size_parse(streamstr); + if (sd == NULL) + return -1; + + SigMatch *sm = SigMatchAlloc(); + if (sm == NULL) { + DetectStreamSizeFree(de_ctx, sd); + return -1; + } + + sm->type = DETECT_STREAM_SIZE; + sm->ctx = (SigMatchCtx *)sd; + + SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH); + return 0; +} + +/** + * \brief this function will free memory associated with DetectStreamSizeData + * + * \param ptr pointer to DetectStreamSizeData + */ +void DetectStreamSizeFree(DetectEngineCtx *de_ctx, void *ptr) +{ + rs_detect_stream_size_free(ptr); +} + +/* prefilter code */ + +static void PrefilterPacketStreamsizeMatch( + DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx) +{ + if (!(PKT_IS_TCP(p)) || PKT_IS_PSEUDOPKT(p)) + return; + + if (p->flow == NULL || p->flow->protoctx == NULL) + return; + + /* during setup Suricata will automatically see if there is another + * check that can be added: alproto, sport or dport */ + const PrefilterPacketHeaderCtx *ctx = pectx; + if (!PrefilterPacketHeaderExtraMatch(ctx, p)) + return; + + DetectStreamSizeData dsd; + dsd.du32.mode = ctx->v1.u8[0]; + dsd.flags = ctx->v1.u8[1]; + dsd.du32.arg1 = ctx->v1.u32[2]; + const TcpSession *ssn = (TcpSession *)p->flow->protoctx; + /* if we match, add all the sigs that use this prefilter. This means + * that these will be inspected further */ + if (DetectStreamSizeMatchAux(&dsd, ssn)) { + PrefilterAddSids(&det_ctx->pmq, ctx->sigs_array, ctx->sigs_cnt); + } +} + +static void PrefilterPacketStreamSizeSet(PrefilterPacketHeaderValue *v, void *smctx) +{ + const DetectStreamSizeData *a = smctx; + v->u8[0] = a->du32.mode; + v->u8[1] = a->flags; + v->u32[2] = a->du32.arg1; +} + +static bool PrefilterPacketStreamSizeCompare(PrefilterPacketHeaderValue v, void *smctx) +{ + const DetectStreamSizeData *a = smctx; + if (v.u8[0] == a->du32.mode && v.u8[1] == a->flags && v.u32[2] == a->du32.arg1) + return true; + return false; +} + +static int PrefilterSetupStreamSize(DetectEngineCtx *de_ctx, SigGroupHead *sgh) +{ + return PrefilterSetupPacketHeader(de_ctx, sgh, DETECT_STREAM_SIZE, PrefilterPacketStreamSizeSet, + PrefilterPacketStreamSizeCompare, PrefilterPacketStreamsizeMatch); +} + +static bool PrefilterStreamSizeIsPrefilterable(const Signature *s) +{ + const SigMatch *sm; + for (sm = s->init_data->smlists[DETECT_SM_LIST_MATCH]; sm != NULL; sm = sm->next) { + switch (sm->type) { + case DETECT_STREAM_SIZE: + return true; + } + } + return false; +} + +#ifdef UNITTESTS +/** + * \test DetectStreamSizeParseTest01 is a test to make sure that we parse the + * user options correctly, when given valid stream_size options. + */ + +static int DetectStreamSizeParseTest01 (void) +{ + int result = 0; + DetectStreamSizeData *sd = NULL; + sd = rs_detect_stream_size_parse("server,<,6"); + if (sd != NULL) { + if (sd->flags & StreamSizeServer && sd->du32.mode == DETECT_UINT_LT && sd->du32.arg1 == 6) + result = 1; + DetectStreamSizeFree(NULL, sd); + } + + return result; +} + +/** + * \test DetectStreamSizeParseTest02 is a test to make sure that we detect the + * invalid stream_size options. + */ + +static int DetectStreamSizeParseTest02 (void) +{ + int result = 1; + DetectStreamSizeData *sd = NULL; + sd = rs_detect_stream_size_parse("invalidoption,<,6"); + if (sd != NULL) { + printf("expected: NULL got 0x%02X %" PRIu32 ": ", sd->flags, sd->du32.arg1); + result = 0; + DetectStreamSizeFree(NULL, sd); + } + + return result; +} + +/** + * \test DetectStreamSizeParseTest03 is a test to make sure that we match the + * packet correctly provided valid stream size. + */ + +static int DetectStreamSizeParseTest03 (void) +{ + + int result = 0; + DetectStreamSizeData *sd = NULL; + TcpSession ssn; + ThreadVars tv; + DetectEngineThreadCtx dtx; + Packet *p = PacketGetFromAlloc(); + if (unlikely(p == NULL)) + return 0; + Signature s; + SigMatch sm; + TcpStream client; + Flow f; + TCPHdr tcph; + + memset(&ssn, 0, sizeof(TcpSession)); + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtx, 0, sizeof(DetectEngineThreadCtx)); + memset(&s, 0, sizeof(Signature)); + memset(&sm, 0, sizeof(SigMatch)); + memset(&client, 0, sizeof(TcpStream)); + memset(&f, 0, sizeof(Flow)); + memset(&tcph, 0, sizeof(TCPHdr)); + + sd = rs_detect_stream_size_parse("client,>,8"); + if (sd != NULL) { + if (!(sd->flags & StreamSizeClient)) { + printf("sd->flags not STREAM_SIZE_CLIENT: "); + DetectStreamSizeFree(NULL, sd); + SCFree(p); + return 0; + } + + if (sd->du32.mode != DETECT_UINT_GT) { + printf("sd->mode not DETECTSSIZE_GT: "); + DetectStreamSizeFree(NULL, sd); + SCFree(p); + return 0; + } + + if (sd->du32.arg1 != 8) { + printf("sd->ssize is %" PRIu32 ", not 8: ", sd->du32.arg1); + DetectStreamSizeFree(NULL, sd); + SCFree(p); + return 0; + } + } else { + printf("sd == NULL: "); + SCFree(p); + return 0; + } + + client.next_seq = 20; + client.isn = 10; + ssn.client = client; + f.protoctx = &ssn; + p->flow = &f; + p->tcph = &tcph; + sm.ctx = (SigMatchCtx*)sd; + + result = DetectStreamSizeMatch(&dtx, p, &s, sm.ctx); + if (result == 0) { + printf("result 0 != 1: "); + } + DetectStreamSizeFree(NULL, sd); + SCFree(p); + return result; +} + +/** + * \test DetectStreamSizeParseTest04 is a test to make sure that we match the + * stream_size against invalid packet parameters. + */ + +static int DetectStreamSizeParseTest04 (void) +{ + + int result = 0; + DetectStreamSizeData *sd = NULL; + TcpSession ssn; + ThreadVars tv; + DetectEngineThreadCtx dtx; + Packet *p = PacketGetFromAlloc(); + if (unlikely(p == NULL)) + return 0; + Signature s; + SigMatch sm; + TcpStream client; + Flow f; + IPV4Hdr ip4h; + + memset(&ssn, 0, sizeof(TcpSession)); + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtx, 0, sizeof(DetectEngineThreadCtx)); + memset(&s, 0, sizeof(Signature)); + memset(&sm, 0, sizeof(SigMatch)); + memset(&client, 0, sizeof(TcpStream)); + memset(&f, 0, sizeof(Flow)); + memset(&ip4h, 0, sizeof(IPV4Hdr)); + + sd = rs_detect_stream_size_parse(" client , > , 8 "); + if (sd != NULL) { + if (!(sd->flags & StreamSizeClient) && sd->du32.mode != DETECT_UINT_GT && + sd->du32.arg1 != 8) { + SCFree(p); + return 0; + } + } else + { + SCFree(p); + return 0; + } + + client.next_seq = 20; + client.isn = 12; + ssn.client = client; + f.protoctx = &ssn; + p->flow = &f; + p->ip4h = &ip4h; + sm.ctx = (SigMatchCtx*)sd; + + if (!DetectStreamSizeMatch(&dtx, p, &s, sm.ctx)) + result = 1; + + SCFree(p); + return result; +} + +/** + * \brief this function registers unit tests for DetectStreamSize + */ +void DetectStreamSizeRegisterTests(void) +{ + UtRegisterTest("DetectStreamSizeParseTest01", DetectStreamSizeParseTest01); + UtRegisterTest("DetectStreamSizeParseTest02", DetectStreamSizeParseTest02); + UtRegisterTest("DetectStreamSizeParseTest03", DetectStreamSizeParseTest03); + UtRegisterTest("DetectStreamSizeParseTest04", DetectStreamSizeParseTest04); +} +#endif /* UNITTESTS */ |