suricata
detect-itype.c
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1 /* Copyright (C) 2007-2020 Open Information Security Foundation
2  *
3  * You can copy, redistribute or modify this Program under the terms of
4  * the GNU General Public License version 2 as published by the Free
5  * Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * version 2 along with this program; if not, write to the Free Software
14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15  * 02110-1301, USA.
16  */
17 
18 /**
19  * \file
20  *
21  * \author Gerardo Iglesias <iglesiasg@gmail.com>
22  *
23  * Implements itype keyword support
24  */
25 
26 #include "suricata-common.h"
27 #include "decode.h"
28 
29 #include "detect.h"
30 #include "detect-parse.h"
32 #include "detect-engine-build.h"
33 
34 #include "detect-itype.h"
35 #include "detect-engine-uint.h"
36 
37 #include "util-byte.h"
38 #include "util-unittest.h"
39 #include "util-unittest-helper.h"
40 #include "util-debug.h"
41 
42 
43 static int DetectITypeMatch(DetectEngineThreadCtx *, Packet *,
44  const Signature *, const SigMatchCtx *);
45 static int DetectITypeSetup(DetectEngineCtx *, Signature *, const char *);
46 #ifdef UNITTESTS
47 static void DetectITypeRegisterTests(void);
48 #endif
49 void DetectITypeFree(DetectEngineCtx *, void *);
50 
51 static int PrefilterSetupIType(DetectEngineCtx *de_ctx, SigGroupHead *sgh);
52 static bool PrefilterITypeIsPrefilterable(const Signature *s);
53 
54 /**
55  * \brief Registration function for itype: keyword
56  */
58 {
59  sigmatch_table[DETECT_ITYPE].name = "itype";
60  sigmatch_table[DETECT_ITYPE].desc = "match on a specific ICMP type";
61  sigmatch_table[DETECT_ITYPE].url = "/rules/header-keywords.html#itype";
62  sigmatch_table[DETECT_ITYPE].Match = DetectITypeMatch;
63  sigmatch_table[DETECT_ITYPE].Setup = DetectITypeSetup;
65 #ifdef UNITTESTS
66  sigmatch_table[DETECT_ITYPE].RegisterTests = DetectITypeRegisterTests;
67 #endif
68  sigmatch_table[DETECT_ITYPE].SupportsPrefilter = PrefilterITypeIsPrefilterable;
69  sigmatch_table[DETECT_ITYPE].SetupPrefilter = PrefilterSetupIType;
70 }
71 
72 /**
73  * \brief This function is used to match itype rule option set on a packet with those passed via
74  * itype:
75  *
76  * \param t pointer to thread vars
77  * \param det_ctx pointer to the pattern matcher thread
78  * \param p pointer to the current packet
79  * \param m pointer to the sigmatch that we will cast into DetectU8Data
80  *
81  * \retval 0 no match
82  * \retval 1 match
83  */
84 static int DetectITypeMatch (DetectEngineThreadCtx *det_ctx, Packet *p,
85  const Signature *s, const SigMatchCtx *ctx)
86 {
88 
89  uint8_t pitype;
90  if (PacketIsICMPv4(p)) {
91  pitype = p->icmp_s.type;
92  } else if (PacketIsICMPv6(p)) {
93  const ICMPV6Hdr *icmpv6h = PacketGetICMPv6(p);
94  pitype = ICMPV6_GET_TYPE(icmpv6h);
95  } else {
96  /* Packet not ICMPv4 nor ICMPv6 */
97  return 0;
98  }
99 
100  const DetectU8Data *itd = (const DetectU8Data *)ctx;
101  return DetectU8Match(pitype, itd);
102 }
103 
104 /**
105  * \brief this function is used to add the parsed itype data into the current signature
106  *
107  * \param de_ctx pointer to the Detection Engine Context
108  * \param s pointer to the Current Signature
109  * \param itypestr pointer to the user provided itype options
110  *
111  * \retval 0 on Success
112  * \retval -1 on Failure
113  */
114 static int DetectITypeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *itypestr)
115 {
116 
117  DetectU8Data *itd = NULL;
118 
119  itd = DetectU8Parse(itypestr);
120  if (itd == NULL)
121  return -1;
122 
124  NULL) {
125  DetectITypeFree(de_ctx, itd);
126  return -1;
127  }
129 
130  return 0;
131 }
132 
133 /**
134  * \brief this function will free memory associated with DetectU8Data
135  *
136  * \param ptr pointer to DetectU8Data
137  */
139 {
140  DetectU8Data *itd = (DetectU8Data *)ptr;
141  rs_detect_u8_free(itd);
142 }
143 
144 /* prefilter code
145  *
146  * Prefilter uses the U8Hash logic, where we setup a 256 entry array
147  * for each ICMP type. Each array element has the list of signatures
148  * that need to be inspected. */
149 
150 static void PrefilterPacketITypeMatch(DetectEngineThreadCtx *det_ctx,
151  Packet *p, const void *pectx)
152 {
154 
155  uint8_t pitype;
156  if (PacketIsICMPv4(p)) {
157  pitype = p->icmp_s.type;
158  } else if (PacketIsICMPv6(p)) {
159  const ICMPV6Hdr *icmpv6h = PacketGetICMPv6(p);
160  pitype = ICMPV6_GET_TYPE(icmpv6h);
161  } else {
162  /* Packet not ICMPv4 nor ICMPv6 */
163  return;
164  }
165 
166  const PrefilterPacketU8HashCtx *h = pectx;
167  const SigsArray *sa = h->array[pitype];
168  if (sa) {
169  PrefilterAddSids(&det_ctx->pmq, sa->sigs, sa->cnt);
170  }
171 }
172 
173 static int PrefilterSetupIType(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
174 {
176  PrefilterPacketU8Set, PrefilterPacketU8Compare, PrefilterPacketITypeMatch);
177 }
178 
179 static bool PrefilterITypeIsPrefilterable(const Signature *s)
180 {
181  const SigMatch *sm;
182  for (sm = s->init_data->smlists[DETECT_SM_LIST_MATCH] ; sm != NULL; sm = sm->next) {
183  switch (sm->type) {
184  case DETECT_ITYPE:
185  return true;
186  }
187  }
188  return false;
189 }
190 
191 #ifdef UNITTESTS
192 
193 #include "detect-engine.h"
194 #include "detect-engine-mpm.h"
195 
196 /**
197  * \test DetectITypeParseTest01 is a test for setting a valid itype value
198  */
199 static int DetectITypeParseTest01(void)
200 {
201  DetectU8Data *itd = NULL;
202  itd = DetectU8Parse("8");
203  FAIL_IF_NULL(itd);
204  FAIL_IF_NOT(itd->arg1 == 8);
205  FAIL_IF_NOT(itd->mode == DETECT_UINT_EQ);
206  DetectITypeFree(NULL, itd);
207 
208  PASS;
209 }
210 
211 /**
212  * \test DetectITypeParseTest02 is a test for setting a valid itype value
213  * with ">" operator
214  */
215 static int DetectITypeParseTest02(void)
216 {
217  DetectU8Data *itd = NULL;
218  itd = DetectU8Parse(">8");
219  FAIL_IF_NULL(itd);
220  FAIL_IF_NOT(itd->arg1 == 8);
221  FAIL_IF_NOT(itd->mode == DETECT_UINT_GT);
222  DetectITypeFree(NULL, itd);
223 
224  PASS;
225 }
226 
227 /**
228  * \test DetectITypeParseTest03 is a test for setting a valid itype value
229  * with "<" operator
230  */
231 static int DetectITypeParseTest03(void)
232 {
233  DetectU8Data *itd = NULL;
234  itd = DetectU8Parse("<8");
235  FAIL_IF_NULL(itd);
236  FAIL_IF_NOT(itd->arg1 == 8);
237  FAIL_IF_NOT(itd->mode == DETECT_UINT_LT);
238  DetectITypeFree(NULL, itd);
239 
240  PASS;
241 }
242 
243 /**
244  * \test DetectITypeParseTest04 is a test for setting a valid itype value
245  * with "<>" operator
246  */
247 static int DetectITypeParseTest04(void)
248 {
249  DetectU8Data *itd = NULL;
250  itd = DetectU8Parse("8<>20");
251  FAIL_IF_NULL(itd);
252  FAIL_IF_NOT(itd->arg1 == 8);
253  FAIL_IF_NOT(itd->arg2 == 20);
254  FAIL_IF_NOT(itd->mode == DETECT_UINT_RA);
255  DetectITypeFree(NULL, itd);
256 
257  PASS;
258 }
259 
260 /**
261  * \test DetectITypeParseTest05 is a test for setting a valid itype value
262  * with spaces all around
263  */
264 static int DetectITypeParseTest05(void)
265 {
266  DetectU8Data *itd = NULL;
267  itd = DetectU8Parse(" 8 ");
268  FAIL_IF_NULL(itd);
269  FAIL_IF_NOT(itd->arg1 == 8);
270  FAIL_IF_NOT(itd->mode == DETECT_UINT_EQ);
271  DetectITypeFree(NULL, itd);
272 
273  PASS;
274 }
275 
276 /**
277  * \test DetectITypeParseTest06 is a test for setting a valid itype value
278  * with ">" operator and spaces all around
279  */
280 static int DetectITypeParseTest06(void)
281 {
282  DetectU8Data *itd = NULL;
283  itd = DetectU8Parse(" > 8 ");
284  FAIL_IF_NULL(itd);
285  FAIL_IF_NOT(itd->arg1 == 8);
286  FAIL_IF_NOT(itd->mode == DETECT_UINT_GT);
287  DetectITypeFree(NULL, itd);
288 
289  PASS;
290 }
291 
292 /**
293  * \test DetectITypeParseTest07 is a test for setting a valid itype value
294  * with "<>" operator and spaces all around
295  */
296 static int DetectITypeParseTest07(void)
297 {
298  DetectU8Data *itd = NULL;
299  itd = DetectU8Parse(" 8 <> 20 ");
300  FAIL_IF_NULL(itd);
301  FAIL_IF_NOT(itd->arg1 == 8);
302  FAIL_IF_NOT(itd->arg2 == 20);
303  FAIL_IF_NOT(itd->mode == DETECT_UINT_RA);
304  DetectITypeFree(NULL, itd);
305 
306  PASS;
307 }
308 
309 /**
310  * \test DetectITypeParseTest08 is a test for setting an invalid itype value
311  */
312 static int DetectITypeParseTest08(void)
313 {
314  DetectU8Data *itd = NULL;
315  itd = DetectU8Parse("> 8 <> 20");
316  FAIL_IF_NOT_NULL(itd);
317 
318  PASS;
319 }
320 
321 /**
322  * \brief this function registers unit tests for DetectIType
323  */
324 void DetectITypeRegisterTests(void)
325 {
326  UtRegisterTest("DetectITypeParseTest01", DetectITypeParseTest01);
327  UtRegisterTest("DetectITypeParseTest02", DetectITypeParseTest02);
328  UtRegisterTest("DetectITypeParseTest03", DetectITypeParseTest03);
329  UtRegisterTest("DetectITypeParseTest04", DetectITypeParseTest04);
330  UtRegisterTest("DetectITypeParseTest05", DetectITypeParseTest05);
331  UtRegisterTest("DetectITypeParseTest06", DetectITypeParseTest06);
332  UtRegisterTest("DetectITypeParseTest07", DetectITypeParseTest07);
333  UtRegisterTest("DetectITypeParseTest08", DetectITypeParseTest08);
334 }
335 #endif /* UNITTESTS */
util-byte.h
DetectITypeRegister
void DetectITypeRegister(void)
Registration function for itype: keyword.
Definition: detect-itype.c:57
DetectITypeFree
void DetectITypeFree(DetectEngineCtx *, void *)
this function will free memory associated with DetectU8Data
Definition: detect-itype.c:138
detect-engine-uint.h
SigTableElmt_::url
const char * url
Definition: detect.h:1307
detect-engine.h
FAIL_IF_NULL
#define FAIL_IF_NULL(expr)
Fail a test if expression evaluates to NULL.
Definition: util-unittest.h:89
SIG_MASK_REQUIRE_REAL_PKT
#define SIG_MASK_REQUIRE_REAL_PKT
Definition: detect.h:306
SignatureInitData_::smlists
struct SigMatch_ * smlists[DETECT_SM_LIST_MAX]
Definition: detect.h:586
SigTableElmt_::desc
const char * desc
Definition: detect.h:1306
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:127
SigTableElmt_::Free
void(* Free)(DetectEngineCtx *, void *)
Definition: detect.h:1294
SigTableElmt_::name
const char * name
Definition: detect.h:1304
PKT_IS_PSEUDOPKT
#define PKT_IS_PSEUDOPKT(p)
return 1 if the packet is a pseudo packet
Definition: decode.h:1317
SigGroupHead_
Container for matching data for a signature group.
Definition: detect.h:1460
UtRegisterTest
void UtRegisterTest(const char *name, int(*TestFn)(void))
Register unit test.
Definition: util-unittest.c:103
DETECT_UINT_LT
#define DETECT_UINT_LT
Definition: detect-engine-uint.h:37
PrefilterPacketU8HashCtx_::array
SigsArray * array[256]
Definition: detect-engine-prefilter-common.h:53
DetectEngineThreadCtx_::pmq
PrefilterRuleStore pmq
Definition: detect.h:1200
ctx
struct Thresholds ctx
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:841
DETECT_UINT_EQ
#define DETECT_UINT_EQ
Definition: detect-engine-uint.h:35
Packet_::icmp_s
struct Packet_::@29::@36 icmp_s
DETECT_UINT_GT
#define DETECT_UINT_GT
Definition: detect-engine-uint.h:32
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1289
DETECT_ITYPE
@ DETECT_ITYPE
Definition: detect-engine-register.h:47
util-unittest.h
util-unittest-helper.h
FAIL_IF_NOT
#define FAIL_IF_NOT(expr)
Fail a test if expression evaluates to false.
Definition: util-unittest.h:82
SigTableElmt_::SetupPrefilter
int(* SetupPrefilter)(DetectEngineCtx *de_ctx, struct SigGroupHead_ *sgh)
Definition: detect.h:1292
DetectU8Parse
DetectUintData_u8 * DetectU8Parse(const char *u8str)
This function is used to parse u8 options passed via some u8 keyword.
Definition: detect-engine-uint.c:85
decode.h
FAIL_IF_NOT_NULL
#define FAIL_IF_NOT_NULL(expr)
Fail a test if expression evaluates to non-NULL.
Definition: util-unittest.h:96
util-debug.h
PrefilterSetupPacketHeaderU8Hash
int PrefilterSetupPacketHeaderU8Hash(DetectEngineCtx *de_ctx, SigGroupHead *sgh, int sm_type, SignatureMask mask, void(*Set)(PrefilterPacketHeaderValue *v, void *), bool(*Compare)(PrefilterPacketHeaderValue v, void *), void(*Match)(DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx))
Definition: detect-engine-prefilter-common.c:396
PASS
#define PASS
Pass the test.
Definition: util-unittest.h:105
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectEngineThreadCtx_
Definition: detect.h:1093
detect-engine-mpm.h
detect.h
SigMatch_::next
struct SigMatch_ * next
Definition: detect.h:353
DetectU8Data
DetectUintData_u8 DetectU8Data
Definition: detect-engine-uint.h:43
DETECT_SM_LIST_MATCH
@ DETECT_SM_LIST_MATCH
Definition: detect.h:114
PrefilterPacketU8Set
void PrefilterPacketU8Set(PrefilterPacketHeaderValue *v, void *smctx)
Definition: detect-engine-uint.c:90
detect-itype.h
Signature_::flags
uint32_t flags
Definition: detect.h:602
Packet_
Definition: decode.h:473
detect-engine-build.h
Signature_::init_data
SignatureInitData * init_data
Definition: detect.h:670
SigTableElmt_::Match
int(* Match)(DetectEngineThreadCtx *, Packet *, const Signature *, const SigMatchCtx *)
Definition: detect.h:1272
SigMatchCtx_
Used to start a pointer to SigMatch context Should never be dereferenced without casting to something...
Definition: detect.h:344
ICMPV6Hdr_
Definition: decode-icmpv6.h:129
DetectU8Match
int DetectU8Match(const uint8_t parg, const DetectUintData_u8 *du8)
Definition: detect-engine-uint.c:71
SigsArray_::sigs
SigIntId * sigs
Definition: detect-engine-prefilter-common.h:47
suricata-common.h
SigMatch_::type
uint16_t type
Definition: detect.h:350
SigsArray_
Definition: detect-engine-prefilter-common.h:46
SigsArray_::cnt
uint32_t cnt
Definition: detect-engine-prefilter-common.h:48
SigTableElmt_::SupportsPrefilter
bool(* SupportsPrefilter)(const Signature *s)
Definition: detect.h:1291
detect-parse.h
Signature_
Signature container.
Definition: detect.h:601
SigMatch_
a single match condition for a signature
Definition: detect.h:349
ICMPV6_GET_TYPE
#define ICMPV6_GET_TYPE(icmp6h)
Definition: decode-icmpv6.h:101
PrefilterPacketU8Compare
bool PrefilterPacketU8Compare(PrefilterPacketHeaderValue v, void *smctx)
Definition: detect-engine-uint.c:98
PrefilterPacketU8HashCtx_
Definition: detect-engine-prefilter-common.h:52
SigMatchAppendSMToList
SigMatch * SigMatchAppendSMToList(DetectEngineCtx *de_ctx, Signature *s, uint16_t type, SigMatchCtx *ctx, const int list)
Append a SigMatch to the list type.
Definition: detect-parse.c:436
detect-engine-prefilter-common.h
DEBUG_VALIDATE_BUG_ON
#define DEBUG_VALIDATE_BUG_ON(exp)
Definition: util-validate.h:102
DETECT_UINT_RA
#define DETECT_UINT_RA
Definition: detect-engine-uint.h:34
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1296
SIG_FLAG_REQUIRE_PACKET
#define SIG_FLAG_REQUIRE_PACKET
Definition: detect.h:250