suricata
detect-ipv4hdr.c
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1 /* Copyright (C) 2007-2019 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 Victor Julien <victor@inliniac.net>
22  *
23  */
24 
25 #include "suricata-common.h"
26 
27 #include "detect.h"
28 #include "detect-parse.h"
29 #include "detect-engine.h"
30 #include "detect-engine-buffer.h"
31 #include "detect-engine-mpm.h"
34 #include "detect-fast-pattern.h"
35 #include "detect-ipv4hdr.h"
36 
37 /* prototypes */
38 static int DetectIpv4hdrSetup (DetectEngineCtx *, Signature *, const char *);
39 #ifdef UNITTESTS
40 void DetectIpv4hdrRegisterTests (void);
41 #endif
42 
43 static int g_ipv4hdr_buffer_id = 0;
44 
45 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
46  const DetectEngineTransforms *transforms, Packet *p, const int list_id);
47 
48 /**
49  * \brief Registration function for ipv4.hdr: keyword
50  */
52 {
53  sigmatch_table[DETECT_IPV4HDR].name = "ipv4.hdr";
54  sigmatch_table[DETECT_IPV4HDR].desc = "sticky buffer to match on the IPV4 header";
55  sigmatch_table[DETECT_IPV4HDR].url = "/rules/header-keywords.html#ipv4hdr";
56  sigmatch_table[DETECT_IPV4HDR].Setup = DetectIpv4hdrSetup;
58 #ifdef UNITTESTS
60 #endif
61 
62  g_ipv4hdr_buffer_id = DetectBufferTypeRegister("ipv4.hdr");
63  BUG_ON(g_ipv4hdr_buffer_id < 0);
64 
66 
68 
70 }
71 
72 /**
73  * \brief setup ipv4.hdr sticky buffer
74  *
75  * \param de_ctx pointer to the Detection Engine Context
76  * \param s pointer to the Current Signature
77  * \param _unused unused
78  *
79  * \retval 0 on Success
80  * \retval -1 on Failure
81  */
82 static int DetectIpv4hdrSetup (DetectEngineCtx *de_ctx, Signature *s, const char *_unused)
83 {
84  s->proto.flags |= DETECT_PROTO_IPV4; // TODO
85 
87 
88  if (SCDetectBufferSetActiveList(de_ctx, s, g_ipv4hdr_buffer_id) < 0)
89  return -1;
90 
91  return 0;
92 }
93 
94 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
95  const DetectEngineTransforms *transforms, Packet *p, const int list_id)
96 {
97  SCEnter();
98 
99  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
100  if (buffer->inspect == NULL) {
101  if (!PacketIsIPv4(p)) {
102  // DETECT_PROTO_IPV4 does not prefilter
103  return NULL;
104  }
105  const IPV4Hdr *ip4h = PacketGetIPv4(p);
106  uint32_t hlen = IPV4_GET_RAW_HLEN(ip4h);
107  if (((uint8_t *)ip4h + (ptrdiff_t)hlen) >
108  ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p))) {
109  SCLogDebug("data out of range: %p > %p", ((uint8_t *)ip4h + (ptrdiff_t)hlen),
110  ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p)));
111  return NULL;
112  }
113 
114  const uint32_t data_len = hlen;
115  const uint8_t *data = (const uint8_t *)ip4h;
116 
118  det_ctx, list_id, buffer, data, data_len, transforms);
119  }
120 
121  return buffer;
122 }
123 
124 #ifdef UNITTESTS
125 #include "tests/detect-ipv4hdr.c"
126 #endif
PrefilterGenericMpmPktRegister
int PrefilterGenericMpmPktRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:1670
SigTableElmt_::url
const char * url
Definition: detect.h:1431
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1645
SigTableElmt_::desc
const char * desc
Definition: detect.h:1430
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:155
SigTableElmt_::name
const char * name
Definition: detect.h:1428
InspectionBufferSetupAndApplyTransforms
void InspectionBufferSetupAndApplyTransforms(DetectEngineThreadCtx *det_ctx, const int list_id, InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len, const DetectEngineTransforms *transforms)
setup the buffer with our initial data
Definition: detect-engine.c:1570
DetectEngineTransforms
Definition: detect.h:415
SCLogDebug
#define SCLogDebug(...)
Definition: util-debug.h:269
DetectPktMpmRegister
void DetectPktMpmRegister(const char *name, int priority, int(*PrefilterRegister)(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id), InspectionBufferGetPktDataPtr GetData)
register a MPM engine
Definition: detect-engine-mpm.c:541
InspectionBuffer
Definition: detect.h:380
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1422
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:931
SCDetectBufferSetActiveList
int SCDetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine-buffer.c:29
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1413
detect-engine-prefilter.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1429
DetectBufferTypeSupportsPacket
void DetectBufferTypeSupportsPacket(const char *name)
Definition: detect-engine.c:1127
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:18
DetectEngineThreadCtx_
Definition: detect.h:1223
DetectPktInspectEngineRegister
void DetectPktInspectEngineRegister(const char *name, InspectionBufferGetPktDataPtr GetPktData, InspectionBufferPktInspectFunc Callback)
register inspect engine at start up time
Definition: detect-engine.c:135
SCEnter
#define SCEnter(...)
Definition: util-debug.h:271
GET_PKT_DATA
#define GET_PKT_DATA(p)
Definition: decode.h:209
detect-engine-mpm.h
detect.h
IPV4_GET_RAW_HLEN
#define IPV4_GET_RAW_HLEN(ip4h)
Definition: decode-ipv4.h:96
BUG_ON
#define BUG_ON(x)
Definition: suricata-common.h:317
Signature_::flags
uint32_t flags
Definition: detect.h:671
Packet_
Definition: decode.h:492
GET_PKT_LEN
#define GET_PKT_LEN(p)
Definition: decode.h:208
detect-engine-content-inspection.h
IPV4Hdr_
Definition: decode-ipv4.h:72
detect-fast-pattern.h
DetectProto_::flags
uint8_t flags
Definition: detect-engine-proto.h:37
DETECT_PROTO_IPV4
#define DETECT_PROTO_IPV4
Definition: detect-engine-proto.h:31
DetectBufferTypeRegister
int DetectBufferTypeRegister(const char *name)
Definition: detect-engine.c:1093
Signature_::proto
DetectProto proto
Definition: detect.h:689
suricata-common.h
DETECT_IPV4HDR
@ DETECT_IPV4HDR
Definition: detect-engine-register.h:285
detect-engine-buffer.h
DetectIpv4hdrRegister
void DetectIpv4hdrRegister(void)
Registration function for ipv4.hdr: keyword.
Definition: detect-ipv4hdr.c:51
detect-ipv4hdr.c
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:381
DetectIpv4hdrRegisterTests
void DetectIpv4hdrRegisterTests(void)
this function registers unit tests for DetectIpv4hdr
Definition: detect-ipv4hdr.c:44
detect-parse.h
Signature_
Signature container.
Definition: detect.h:670
detect-ipv4hdr.h
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1620
DetectEngineInspectPktBufferGeneric
int DetectEngineInspectPktBufferGeneric(DetectEngineThreadCtx *det_ctx, const DetectEnginePktInspectionEngine *engine, const Signature *s, Packet *p, uint8_t *_alert_flags)
Do the content inspection & validation for a signature.
Definition: detect-engine.c:2234
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1420
SIG_FLAG_REQUIRE_PACKET
#define SIG_FLAG_REQUIRE_PACKET
Definition: detect.h:253