suricata
detect-priority.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 Victor Julien <victor@inliniac.net>
22  * \author Anoop Saldanha <anoopsaldanha@gmail.com>
23  *
24  * Implements the priority keyword
25  */
26 
27 #include "suricata-common.h"
28 #include "detect.h"
29 #include "detect-parse.h"
30 #include "detect-priority.h"
31 #include "detect-engine.h"
32 #include "detect-engine-mpm.h"
33 #include "util-error.h"
34 #include "util-debug.h"
35 #include "util-unittest.h"
36 
37 #define PARSE_REGEX "^\\s*(\\d+|\"\\d+\")\\s*$"
38 
39 static DetectParseRegex parse_regex;
40 
41 static int DetectPrioritySetup (DetectEngineCtx *, Signature *, const char *);
42 #ifdef UNITTESTS
43 static void PriorityRegisterTests(void);
44 #endif
45 
46 /**
47  * \brief Registers the handler functions for the "priority" keyword
48  */
49 void DetectPriorityRegister (void)
50 {
51  sigmatch_table[DETECT_PRIORITY].name = "priority";
52  sigmatch_table[DETECT_PRIORITY].desc = "rules with a higher priority will be examined first";
53  sigmatch_table[DETECT_PRIORITY].url = "/rules/meta.html#priority";
54  sigmatch_table[DETECT_PRIORITY].Setup = DetectPrioritySetup;
55 #ifdef UNITTESTS
56  sigmatch_table[DETECT_PRIORITY].RegisterTests = PriorityRegisterTests;
57 #endif
58  DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);
59 }
60 
61 static int DetectPrioritySetup (DetectEngineCtx *de_ctx, Signature *s, const char *rawstr)
62 {
63  char copy_str[128] = "";
64  size_t pcre2len;
65 
66  pcre2_match_data *match = NULL;
67  int ret = DetectParsePcreExec(&parse_regex, &match, rawstr, 0, 0);
68  if (ret < 0) {
69  SCLogError("Invalid Priority in Signature "
70  "- %s",
71  rawstr);
72  if (match)
73  pcre2_match_data_free(match);
74  return -1;
75  }
76 
77  pcre2len = sizeof(copy_str);
78  ret = pcre2_substring_copy_bynumber(match, 1, (PCRE2_UCHAR8 *)copy_str, &pcre2len);
79  if (ret < 0) {
80  SCLogError("pcre2_substring_copy_bynumber failed");
81  pcre2_match_data_free(match);
82  return -1;
83  }
84 
85  pcre2_match_data_free(match);
86  char *endptr = NULL;
87  long prio = strtol(copy_str, &endptr, 10);
88  if (endptr == NULL || *endptr != '\0') {
89  SCLogError("Saw an invalid character as arg "
90  "to priority keyword");
91  return -1;
92  }
93 
94  if (s->init_data->init_flags & SIG_FLAG_INIT_PRIO_EXPLICIT) {
95  SCLogWarning("duplicate priority "
96  "keyword. Using highest priority in the rule");
97  s->prio = MIN(s->prio, prio);
98  } else {
99  s->prio = prio;
100  s->init_data->init_flags |= SIG_FLAG_INIT_PRIO_EXPLICIT;
101  }
102  return 0;
103 }
104 
105 /*------------------------------Unittests-------------------------------------*/
106 
107 #ifdef UNITTESTS
108 
109 static int DetectPriorityTest01(void)
110 {
111  DetectEngineCtx *de_ctx = DetectEngineCtxInit();
112  FAIL_IF_NULL(de_ctx);
113 
114  de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "
115  "(msg:\"Priority test\"; priority:2; sid:1;)");
116  FAIL_IF_NULL(de_ctx->sig_list);
117 
118  FAIL_IF_NOT(de_ctx->sig_list->prio == 2);
119 
120  DetectEngineCtxFree(de_ctx);
121  PASS;
122 }
123 
124 static int DetectPriorityTest02(void)
125 {
126  DetectEngineCtx *de_ctx = DetectEngineCtxInit();
127  FAIL_IF_NULL(de_ctx);
128 
129  Signature *sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
130  "(msg:\"Priority test\"; priority:1; sid:1;)");
131  FAIL_IF_NULL(sig);
132  FAIL_IF_NOT(sig->prio == 1);
133 
134  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
135  "(msg:\"Priority test\"; priority:boo; sid:2;)");
136  FAIL_IF_NOT_NULL(sig);
137 
138  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
139  "(msg:\"Priority test\"; priority:10boo; sid:3;)");
140  FAIL_IF_NOT_NULL(sig);
141 
142  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
143  "(msg:\"Priority test\"; priority:b10oo; sid:4;)");
144  FAIL_IF_NOT_NULL(sig);
145 
146  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
147  "(msg:\"Priority test\"; priority:boo10; sid:5;)");
148  FAIL_IF_NOT_NULL(sig);
149 
150  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
151  "(msg:\"Priority test\"; priority:-1; sid:6;)");
152  FAIL_IF_NOT_NULL(sig);
153 
154  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
155  "(msg:\"Priority test\"; sid:7;)");
156  FAIL_IF_NULL(sig);
157  FAIL_IF_NOT(sig->prio == 3);
158 
159  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
160  "(msg:\"Priority test\"; priority:5; priority:4; sid:8;)");
161  FAIL_IF_NULL(sig);
162  FAIL_IF_NOT(sig->prio == 4);
163 
164  sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "
165  "(msg:\"Priority test\"; priority:5; priority:4; "
166  "priority:1; sid:9;)");
167  FAIL_IF_NULL(sig);
168  FAIL_IF_NOT(sig->prio == 1);
169 
170  DetectEngineCtxFree(de_ctx);
171  PASS;
172 }
173 
174 /**
175  * \brief This function registers unit tests for Classification Config API.
176  */
177 static void PriorityRegisterTests(void)
178 {
179  UtRegisterTest("DetectPriorityTest01", DetectPriorityTest01);
180  UtRegisterTest("DetectPriorityTest02", DetectPriorityTest02);
181 }
182 #endif /* UNITTESTS */
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
SigTableElmt_::desc
const char * desc
Definition: detect.h:1306
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:127
detect-priority.h
DetectParseRegex
Definition: detect-parse.h:62
SigTableElmt_::name
const char * name
Definition: detect.h:1304
UtRegisterTest
void UtRegisterTest(const char *name, int(*TestFn)(void))
Register unit test.
Definition: util-unittest.c:103
SIG_FLAG_INIT_PRIO_EXPLICIT
#define SIG_FLAG_INIT_PRIO_EXPLICIT
Definition: detect.h:294
DetectPriorityRegister
void DetectPriorityRegister(void)
Registers the handler functions for the "priority" keyword.
Definition: detect-priority.c:49
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:841
DetectEngineCtxFree
void DetectEngineCtxFree(DetectEngineCtx *)
Free a DetectEngineCtx::
Definition: detect-engine.c:2611
MIN
#define MIN(x, y)
Definition: suricata-common.h:391
SignatureInitData_::init_flags
uint32_t init_flags
Definition: detect.h:553
DetectParsePcreExec
int DetectParsePcreExec(DetectParseRegex *parse_regex, pcre2_match_data **match, const char *str, int start_offset, int options)
Definition: detect-parse.c:2641
DetectEngineAppendSig
Signature * DetectEngineAppendSig(DetectEngineCtx *, const char *)
Parse and append a Signature into the Detection Engine Context signature list.
Definition: detect-parse.c:2587
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1289
util-unittest.h
FAIL_IF_NOT
#define FAIL_IF_NOT(expr)
Fail a test if expression evaluates to false.
Definition: util-unittest.h:82
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
PASS
#define PASS
Pass the test.
Definition: util-unittest.h:105
util-error.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectSetupParseRegexes
void DetectSetupParseRegexes(const char *parse_str, DetectParseRegex *detect_parse)
Definition: detect-parse.c:2767
detect-engine-mpm.h
detect.h
DETECT_PRIORITY
@ DETECT_PRIORITY
Definition: detect-engine-register.h:29
SCLogWarning
#define SCLogWarning(...)
Macro used to log WARNING messages.
Definition: util-debug.h:249
SigInit
Signature * SigInit(DetectEngineCtx *de_ctx, const char *sigstr)
Parses a signature and adds it to the Detection Engine Context.
Definition: detect-parse.c:2285
Signature_::init_data
SignatureInitData * init_data
Definition: detect.h:670
suricata-common.h
DetectEngineCtx_::sig_list
Signature * sig_list
Definition: detect.h:849
Signature_::prio
int prio
Definition: detect.h:639
SCLogError
#define SCLogError(...)
Macro used to log ERROR messages.
Definition: util-debug.h:261
detect-parse.h
Signature_
Signature container.
Definition: detect.h:601
DetectEngineCtxInit
DetectEngineCtx * DetectEngineCtxInit(void)
Definition: detect-engine.c:2572
PARSE_REGEX
#define PARSE_REGEX
Definition: detect-priority.c:37
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1296