suricata
detect-http-method.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  * \ingroup httplayer
20  *
21  * @{
22  */
23 
24 
25 /**
26  * \file
27  *
28  * \author Brian Rectanus <brectanu@gmail.com>
29  *
30  * Implements the http_method keyword
31  */
32 
33 #include "suricata-common.h"
34 #include "threads.h"
35 #include "decode.h"
36 #include "detect.h"
37 
38 #include "detect-parse.h"
39 #include "detect-engine.h"
40 #include "detect-engine-mpm.h"
42 #include "detect-content.h"
43 #include "detect-pcre.h"
44 
45 #include "flow.h"
46 #include "flow-var.h"
47 #include "flow-util.h"
48 
49 #include "util-debug.h"
50 #include "util-unittest.h"
51 #include "util-unittest-helper.h"
52 #include "util-spm.h"
53 
54 #include "app-layer.h"
55 #include "app-layer-parser.h"
56 
57 #include "app-layer-htp.h"
58 #include "detect-http-method.h"
59 #include "stream-tcp.h"
60 
61 static int g_http_method_buffer_id = 0;
62 static int DetectHttpMethodSetup(DetectEngineCtx *, Signature *, const char *);
63 static int DetectHttpMethodSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str);
64 #ifdef UNITTESTS
66 #endif
67 void DetectHttpMethodFree(void *);
68 static bool DetectHttpMethodValidateCallback(
69  const Signature *s, const char **sigerror, const DetectBufferType *dbt);
70 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
71  const DetectEngineTransforms *transforms, Flow *_f,
72  const uint8_t _flow_flags, void *txv, const int list_id);
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 /**
78  * \brief Registration function for keyword: http_method
79  */
81 {
82  /* http_method content modifier */
83  sigmatch_table[DETECT_HTTP_METHOD_CM].name = "http_method";
85  "content modifier to match only on the HTTP method-buffer";
86  sigmatch_table[DETECT_HTTP_METHOD_CM].url = "/rules/http-keywords.html#http-method";
88  sigmatch_table[DETECT_HTTP_METHOD_CM].Setup = DetectHttpMethodSetup;
89 #ifdef UNITTESTS
91 #endif
94 
95  /* http.method sticky buffer */
96  sigmatch_table[DETECT_HTTP_METHOD].name = "http.method";
97  sigmatch_table[DETECT_HTTP_METHOD].desc = "sticky buffer to match specifically and only on the HTTP method buffer";
98  sigmatch_table[DETECT_HTTP_METHOD].url = "/rules/http-keywords.html#http-method";
99  sigmatch_table[DETECT_HTTP_METHOD].Setup = DetectHttpMethodSetupSticky;
101 
103  HTP_REQUEST_PROGRESS_LINE, DetectEngineInspectBufferGeneric, GetData);
104 
106  GetData, ALPROTO_HTTP1, HTP_REQUEST_PROGRESS_LINE);
107 
109  HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetData2);
110 
112  GetData2, ALPROTO_HTTP2, HTTP2StateDataClient);
113 
115  "http request method");
116 
118  DetectHttpMethodValidateCallback);
119 
120  g_http_method_buffer_id = DetectBufferTypeGetByName("http_method");
121 
122  SCLogDebug("registering http_method rule option");
123 }
124 
125 /**
126  * \brief This function is used to add the parsed "http_method" option
127  * into the current signature.
128  *
129  * \param de_ctx Pointer to the Detection Engine Context.
130  * \param s Pointer to the Current Signature.
131  * \param str Pointer to the user provided option string.
132  *
133  * \retval 0 on Success.
134  * \retval -1 on Failure.
135  */
136 static int DetectHttpMethodSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
137 {
139  de_ctx, s, str, DETECT_HTTP_METHOD_CM, g_http_method_buffer_id, ALPROTO_HTTP1);
140 }
141 
142 /**
143  * \brief this function setup the http.method keyword used in the rule
144  *
145  * \param de_ctx Pointer to the Detection Engine Context
146  * \param s Pointer to the Signature to which the current keyword belongs
147  * \param str Should hold an empty string always
148  *
149  * \retval 0 On success
150  */
151 static int DetectHttpMethodSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str)
152 {
153  if (DetectBufferSetActiveList(de_ctx, s, g_http_method_buffer_id) < 0)
154  return -1;
155 
157  return -1;
158 
159  return 0;
160 }
161 
162 /**
163  * \retval 1 valid
164  * \retval 0 invalid
165  */
166 static bool DetectHttpMethodValidateCallback(
167  const Signature *s, const char **sigerror, const DetectBufferType *dbt)
168 {
169  for (uint32_t x = 0; x < s->init_data->buffer_index; x++) {
170  if (s->init_data->buffers[x].id != (uint32_t)dbt->id)
171  continue;
172  const SigMatch *sm = s->init_data->buffers[x].head;
173  for (; sm != NULL; sm = sm->next) {
174  if (sm->type != DETECT_CONTENT)
175  continue;
176  const DetectContentData *cd = (const DetectContentData *)sm->ctx;
177  if (cd->content && cd->content_len) {
178  if (cd->content[cd->content_len - 1] == 0x20) {
179  *sigerror = "http_method pattern with trailing space";
180  SCLogError("%s", *sigerror);
181  return false;
182  } else if (cd->content[0] == 0x20) {
183  *sigerror = "http_method pattern with leading space";
184  SCLogError("%s", *sigerror);
185  return false;
186  } else if (cd->content[cd->content_len - 1] == 0x09) {
187  *sigerror = "http_method pattern with trailing tab";
188  SCLogError("%s", *sigerror);
189  return false;
190  } else if (cd->content[0] == 0x09) {
191  *sigerror = "http_method pattern with leading tab";
192  SCLogError("%s", *sigerror);
193  return false;
194  }
195  }
196  }
197  }
198  return true;
199 }
200 
201 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
202  const DetectEngineTransforms *transforms, Flow *_f,
203  const uint8_t _flow_flags, void *txv, const int list_id)
204 {
205  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
206  if (buffer->inspect == NULL) {
207  htp_tx_t *tx = (htp_tx_t *)txv;
208 
209  if (htp_tx_request_method(tx) == NULL)
210  return NULL;
211 
212  const uint32_t data_len = bstr_len(htp_tx_request_method(tx));
213  const uint8_t *data = bstr_ptr(htp_tx_request_method(tx));
214 
216  det_ctx, list_id, buffer, data, data_len, transforms);
217  }
218 
219  return buffer;
220 }
221 
222 static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx,
223  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
224  const int list_id)
225 {
226  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
227  if (buffer->inspect == NULL) {
228  uint32_t b_len = 0;
229  const uint8_t *b = NULL;
230 
231  if (rs_http2_tx_get_method(txv, &b, &b_len) != 1)
232  return NULL;
233  if (b == NULL || b_len == 0)
234  return NULL;
235 
236  InspectionBufferSetupAndApplyTransforms(det_ctx, list_id, buffer, b, b_len, transforms);
237  }
238 
239  return buffer;
240 }
241 
242 #ifdef UNITTESTS
244 #endif
245 
246 /**
247  * @}
248  */
SigTableElmt_::url
const char * url
Definition: detect.h:1405
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:2218
SignatureInitDataBuffer_::head
SigMatch * head
Definition: detect.h:547
detect-content.h
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1616
SigTableElmt_::desc
const char * desc
Definition: detect.h:1404
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:155
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:2252
flow-util.h
SIGMATCH_INFO_CONTENT_MODIFIER
#define SIGMATCH_INFO_CONTENT_MODIFIER
Definition: detect.h:1614
SigTableElmt_::name
const char * name
Definition: detect.h:1402
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:1719
stream-tcp.h
DetectEngineTransforms
Definition: detect.h:415
DETECT_CONTENT
@ DETECT_CONTENT
Definition: detect-engine-register.h:69
SCLogDebug
#define SCLogDebug(...)
Definition: util-debug.h:269
DETECT_HTTP_METHOD
@ DETECT_HTTP_METHOD
Definition: detect-engine-register.h:152
DetectBufferSetActiveList
int DetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine.c:1422
InspectionBuffer
Definition: detect.h:380
threads.h
Flow_
Flow data structure.
Definition: flow.h:356
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1396
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:920
DetectBufferTypeRegisterValidateCallback
void DetectBufferTypeRegisterValidateCallback(const char *name, bool(*ValidateCallback)(const Signature *, const char **sigerror, const DetectBufferType *))
Definition: detect-engine.c:1369
DetectBufferType_
Definition: detect.h:463
DetectContentData_
Definition: detect-content.h:93
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1387
detect-pcre.h
detect-engine-prefilter.h
util-unittest.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1578
util-unittest-helper.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1157
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:270
app-layer-htp.h
decode.h
util-debug.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:18
DetectEngineThreadCtx_
Definition: detect.h:1197
detect-engine-mpm.h
detect.h
SigMatch_::next
struct SigMatch_ * next
Definition: detect.h:360
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:1547
SigTableElmt_::alternative
uint16_t alternative
Definition: detect.h:1400
DetectAppLayerMpmRegister
void DetectAppLayerMpmRegister(const char *name, int direction, int priority, PrefilterRegisterFunc PrefilterRegister, InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register an app layer keyword for mpm
Definition: detect-engine-mpm.c:151
app-layer-parser.h
SigMatch_::ctx
SigMatchCtx * ctx
Definition: detect.h:359
DetectHttpMethodRegisterTests
void DetectHttpMethodRegisterTests(void)
this function registers unit tests for DetectHttpMethod
Definition: detect-http-method.c:2155
DetectEngineContentModifierBufferSetup
int DetectEngineContentModifierBufferSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg, int sm_type, int sm_list, AppProto alproto)
Definition: detect-parse.c:222
Signature_::init_data
SignatureInitData * init_data
Definition: detect.h:748
SigTableElmt_::Match
int(* Match)(DetectEngineThreadCtx *, Packet *, const Signature *, const SigMatchCtx *)
Definition: detect.h:1370
DetectHttpMethodFree
void DetectHttpMethodFree(void *)
ALPROTO_HTTP2
@ ALPROTO_HTTP2
Definition: app-layer-protos.h:69
DetectBufferType_::id
int id
Definition: detect.h:466
suricata-common.h
SigMatch_::type
uint16_t type
Definition: detect.h:357
ALPROTO_HTTP1
@ ALPROTO_HTTP1
Definition: app-layer-protos.h:36
util-spm.h
DetectContentData_::content
uint8_t * content
Definition: detect-content.h:94
SignatureInitData_::buffers
SignatureInitDataBuffer * buffers
Definition: detect.h:648
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:381
str
#define str(s)
Definition: suricata-common.h:300
detect-http-method.h
SCLogError
#define SCLogError(...)
Macro used to log ERROR messages.
Definition: util-debug.h:261
detect-http-method.c
Handle HTTP method match.
detect-parse.h
SignatureInitDataBuffer_::id
uint32_t id
Definition: detect.h:538
Signature_
Signature container.
Definition: detect.h:669
SigMatch_
a single match condition for a signature
Definition: detect.h:356
ALPROTO_HTTP
@ ALPROTO_HTTP
Definition: app-layer-protos.h:75
DETECT_HTTP_METHOD_CM
@ DETECT_HTTP_METHOD_CM
Definition: detect-engine-register.h:151
DetectContentData_::content_len
uint16_t content_len
Definition: detect-content.h:95
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1592
DetectAppLayerInspectEngineRegister
void DetectAppLayerInspectEngineRegister(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr Callback, InspectionBufferGetDataPtr GetData)
Registers an app inspection engine.
Definition: detect-engine.c:245
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1254
flow.h
SignatureInitData_::buffer_index
uint32_t buffer_index
Definition: detect.h:649
flow-var.h
DetectHttpMethodRegister
void DetectHttpMethodRegister(void)
Registration function for keyword: http_method.
Definition: detect-http-method.c:80
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1394
app-layer.h