suricata
detect-http-response-line.c
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1 /* Copyright (C) 2007-2022 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  * \ingroup httplayer
20  *
21  * @{
22  */
23 
24 
25 /**
26  * \file
27  *
28  * \author Victor Julien <victor@inliniac.net>
29  *
30  * Implements support for the http_response_line keyword.
31  */
32 
33 #include "suricata-common.h"
34 #include "threads.h"
35 #include "decode.h"
36 
37 #include "detect.h"
38 #include "detect-parse.h"
39 #include "detect-engine.h"
40 #include "detect-engine-mpm.h"
41 #include "detect-engine-state.h"
42 #include "detect-engine-prefilter.h"
43 #include "detect-engine-content-inspection.h"
44 #include "detect-content.h"
45 #include "detect-pcre.h"
46 
47 #include "flow.h"
48 #include "flow-var.h"
49 #include "flow-util.h"
50 
51 #include "util-debug.h"
52 #include "util-unittest.h"
53 #include "util-unittest-helper.h"
54 #include "util-spm.h"
55 
56 #include "app-layer.h"
57 #include "app-layer-parser.h"
58 
59 #include "app-layer-htp.h"
60 #include "stream-tcp.h"
61 #include "detect-http-response-line.h"
62 
63 static int DetectHttpResponseLineSetup(DetectEngineCtx *, Signature *, const char *);
64 #ifdef UNITTESTS
65 static void DetectHttpResponseLineRegisterTests(void);
66 #endif
67 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
68  const DetectEngineTransforms *transforms,
69  Flow *_f, const uint8_t _flow_flags,
70  void *txv, const int list_id);
71 static int g_http_response_line_id = 0;
72 
73 static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx,
74  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
75  const int list_id)
76 {
77  SCEnter();
78 
79  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
80  if (buffer->inspect == NULL) {
81  uint32_t b_len = 0;
82  const uint8_t *b = NULL;
83 
84  if (rs_http2_tx_get_response_line(txv, &b, &b_len) != 1)
85  return NULL;
86  if (b == NULL || b_len == 0)
87  return NULL;
88 
89  InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
90  InspectionBufferApplyTransforms(buffer, transforms);
91  }
92 
93  return buffer;
94 }
95 
96 /**
97  * \brief Registers the keyword handlers for the "http_response_line" keyword.
98  */
99 void DetectHttpResponseLineRegister(void)
100 {
101  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].name = "http.response_line";
102  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].alias = "http_response_line";
103  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].desc = "content modifier to match only on the HTTP response line";
104  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].url = "/rules/http-keywords.html#http-response-line";
105  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].Setup = DetectHttpResponseLineSetup;
106 #ifdef UNITTESTS
107  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].RegisterTests = DetectHttpResponseLineRegisterTests;
108 #endif
109  sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
110 
111  DetectAppLayerInspectEngineRegister2("http_response_line", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT,
112  HTP_RESPONSE_LINE, DetectEngineInspectBufferGeneric, GetData);
113 
114  DetectAppLayerMpmRegister2("http_response_line", SIG_FLAG_TOCLIENT, 2,
115  PrefilterGenericMpmRegister, GetData, ALPROTO_HTTP1, HTP_RESPONSE_LINE);
116 
117  DetectAppLayerInspectEngineRegister2("http_response_line", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT,
118  HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetData2);
119  DetectAppLayerMpmRegister2("http_response_line", SIG_FLAG_TOCLIENT, 2,
120  PrefilterGenericMpmRegister, GetData2, ALPROTO_HTTP2, HTTP2StateDataServer);
121 
122  DetectBufferTypeSetDescriptionByName("http_response_line",
123  "http response line");
124 
125  g_http_response_line_id = DetectBufferTypeGetByName("http_response_line");
126 }
127 
128 /**
129  * \brief The setup function for the http_response_line keyword for a signature.
130  *
131  * \param de_ctx Pointer to the detection engine context.
132  * \param s Pointer to the signature for the current Signature being
133  * parsed from the rules.
134  * \param m Pointer to the head of the SigMatch for the current rule
135  * being parsed.
136  * \param arg Pointer to the string holding the keyword value.
137  *
138  * \retval 0 On success
139  * \retval -1 On failure
140  */
141 static int DetectHttpResponseLineSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
142 {
143  if (DetectBufferSetActiveList(de_ctx, s, g_http_response_line_id) < 0)
144  return -1;
145 
146  if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0)
147  return -1;
148 
149  return 0;
150 }
151 
152 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
153  const DetectEngineTransforms *transforms,
154  Flow *_f, const uint8_t _flow_flags,
155  void *txv, const int list_id)
156 {
157  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
158  if (buffer->inspect == NULL) {
159  htp_tx_t *tx = (htp_tx_t *)txv;
160  if (unlikely(tx->response_line == NULL)) {
161  return NULL;
162  }
163  const uint32_t data_len = bstr_len(tx->response_line);
164  const uint8_t *data = bstr_ptr(tx->response_line);
165 
166  InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
167  InspectionBufferApplyTransforms(buffer, transforms);
168  }
169  return buffer;
170 }
171 
172 /************************************Unittests*********************************/
173 
174 #ifdef UNITTESTS
175 
176 #include "stream-tcp-reassemble.h"
177 
178 /**
179  * \test Test that a signature containing a http_response_line is correctly parsed
180  * and the keyword is registered.
181  */
182 static int DetectHttpResponseLineTest01(void)
183 {
184  DetectEngineCtx *de_ctx = DetectEngineCtxInit();
185  FAIL_IF_NULL(de_ctx);
186 
187  de_ctx->flags |= DE_QUIET;
188  de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "
189  "(http_response_line; content:\"200 OK\"; sid:1;)");
190  FAIL_IF_NULL(de_ctx->sig_list);
191 
192  DetectEngineCtxFree(de_ctx);
193  PASS;
194 }
195 
196 void DetectHttpResponseLineRegisterTests(void)
197 {
198  UtRegisterTest("DetectHttpResponseLineTest01", DetectHttpResponseLineTest01);
199 }
200 #endif /* UNITTESTS */
201 /**
202  * @}
203  */
SigTableElmt_::url
const char * url
Definition: detect.h:1288
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:1704
detect-content.h
detect-engine.h
DetectAppLayerMpmRegister2
void DetectAppLayerMpmRegister2(const char *name, int direction, int priority, PrefilterRegisterFunc PrefilterRegister, InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register a MPM engine
Definition: detect-engine-mpm.c:89
FAIL_IF_NULL
#define FAIL_IF_NULL(expr)
Fail a test if expression evaluates to NULL.
Definition: util-unittest.h:89
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1491
SigTableElmt_::desc
const char * desc
Definition: detect.h:1287
DetectEngineInspectBufferGeneric
uint8_t DetectEngineInspectBufferGeneric(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id)
Do the content inspection & validation for a signature.
Definition: detect-engine.c:2165
flow-util.h
SigTableElmt_::name
const char * name
Definition: detect.h:1285
stream-tcp.h
unlikely
#define unlikely(expr)
Definition: util-optimize.h:35
DetectEngineTransforms
Definition: detect.h:400
UtRegisterTest
void UtRegisterTest(const char *name, int(*TestFn)(void))
Register unit test.
Definition: util-unittest.c:103
DetectBufferSetActiveList
int DetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine.c:1387
InspectionBuffer
Definition: detect.h:365
threads.h
Flow_
Flow data structure.
Definition: flow.h:347
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1279
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:827
DetectEngineCtxFree
void DetectEngineCtxFree(DetectEngineCtx *)
Free a DetectEngineCtx::
Definition: detect-engine.c:2592
DE_QUIET
#define DE_QUIET
Definition: detect.h:315
stream-tcp-reassemble.h
SIG_FLAG_TOCLIENT
#define SIG_FLAG_TOCLIENT
Definition: detect.h:256
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1270
detect-pcre.h
detect-engine-prefilter.h
util-unittest.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1526
util-unittest-helper.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1124
app-layer-htp.h
decode.h
util-debug.h
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:1075
detect-http-response-line.h
SCEnter
#define SCEnter(...)
Definition: util-debug.h:271
detect-engine-mpm.h
detect.h
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:745
SigInit
Signature * SigInit(DetectEngineCtx *de_ctx, const char *sigstr)
Parses a signature and adds it to the Detection Engine Context.
Definition: detect-parse.c:2270
app-layer-parser.h
DetectAppLayerInspectEngineRegister2
void DetectAppLayerInspectEngineRegister2(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr2 Callback2, InspectionBufferGetDataPtr GetData)
register inspect engine at start up time
Definition: detect-engine.c:216
detect-engine-state.h
Data structures and function prototypes for keeping state for the detection engine.
DETECT_AL_HTTP_RESPONSE_LINE
@ DETECT_AL_HTTP_RESPONSE_LINE
Definition: detect-engine-register.h:165
ALPROTO_HTTP2
@ ALPROTO_HTTP2
Definition: app-layer-protos.h:61
detect-engine-content-inspection.h
DetectHttpResponseLineRegister
void DetectHttpResponseLineRegister(void)
Registers the keyword handlers for the "http_response_line" keyword.
Definition: detect-http-response-line.c:99
SigTableElmt_::alias
const char * alias
Definition: detect.h:1286
suricata-common.h
InspectionBufferApplyTransforms
void InspectionBufferApplyTransforms(InspectionBuffer *buffer, const DetectEngineTransforms *transforms)
Definition: detect-engine.c:1725
ALPROTO_HTTP1
@ ALPROTO_HTTP1
Definition: app-layer-protos.h:30
sigmatch_table
SigTableElmt sigmatch_table[DETECT_TBLSIZE]
Definition: detect-parse.c:129
util-spm.h
DetectEngineCtx_::sig_list
Signature * sig_list
Definition: detect.h:835
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:366
InspectionBufferSetup
void InspectionBufferSetup(DetectEngineThreadCtx *det_ctx, const int list_id, InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
setup the buffer with our initial data
Definition: detect-engine.c:1621
detect-parse.h
Signature_
Signature container.
Definition: detect.h:582
ALPROTO_HTTP
@ ALPROTO_HTTP
Definition: app-layer-protos.h:66
DetectEngineCtxInit
DetectEngineCtx * DetectEngineCtxInit(void)
Definition: detect-engine.c:2553
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1467
DetectEngineCtx_::flags
uint8_t flags
Definition: detect.h:829
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1221
flow.h
flow-var.h
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1277
app-layer.h