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1 /*************************************************
2 *      Perl-Compatible Regular Expressions       *
3 *************************************************/
4 
5 /* PCRE is a library of functions to support regular expressions whose syntax
6 and semantics are as close as possible to those of the Perl 5 language.
7 
8                        Written by Philip Hazel
9      Original API code Copyright (c) 1997-2012 University of Cambridge
10          New API code Copyright (c) 2016 University of Cambridge
11 
12 -----------------------------------------------------------------------------
13 Redistribution and use in source and binary forms, with or without
14 modification, are permitted provided that the following conditions are met:
15 
16     * Redistributions of source code must retain the above copyright notice,
17       this list of conditions and the following disclaimer.
18 
19     * Redistributions in binary form must reproduce the above copyright
20       notice, this list of conditions and the following disclaimer in the
21       documentation and/or other materials provided with the distribution.
22 
23     * Neither the name of the University of Cambridge nor the names of its
24       contributors may be used to endorse or promote products derived from
25       this software without specific prior written permission.
26 
27 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
28 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
31 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 POSSIBILITY OF SUCH DAMAGE.
38 -----------------------------------------------------------------------------
39 */
40 
41 
42 /* This module is a wrapper that provides a POSIX API to the underlying PCRE2
43 functions. */
44 
45 
46 #ifdef HAVE_CONFIG_H
47 #include "config.h"
48 #endif
49 
50 
51 /* Ensure that the PCRE2POSIX_EXP_xxx macros are set appropriately for
52 compiling these functions. This must come before including pcre2posix.h, where
53 they are set for an application (using these functions) if they have not
54 previously been set. */
55 
56 #if defined(_WIN32) && !defined(PCRE2_STATIC)
57 #  define PCRE2POSIX_EXP_DECL extern __declspec(dllexport)
58 #  define PCRE2POSIX_EXP_DEFN __declspec(dllexport)
59 #endif
60 
61 /* Older versions of MSVC lack snprintf(). This define allows for
62 warning/error-free compilation and testing with MSVC compilers back to at least
63 MSVC 10/2010. Except for VC6 (which is missing some fundamentals and fails). */
64 
65 #if defined(_MSC_VER) && (_MSC_VER < 1900)
66 #define snprintf _snprintf
67 #endif
68 
69 
70 /* Compile-time error numbers start at this value. It should probably never be
71 changed. This #define is a copy of the one in pcre2_internal.h. */
72 
73 #define COMPILE_ERROR_BASE 100
74 
75 
76 /* Standard C headers */
77 
78 #include <ctype.h>
79 #include <limits.h>
80 #include <stddef.h>
81 #include <stdio.h>
82 #include <stdlib.h>
83 #include <string.h>
84 
85 /* PCRE2 headers */
86 
87 #include "pcre2.h"
88 #include "pcre2posix.h"
89 
90 /* When compiling with the MSVC compiler, it is sometimes necessary to include
91 a "calling convention" before exported function names. (This is secondhand
92 information; I know nothing about MSVC myself). For example, something like
93 
94   void __cdecl function(....)
95 
96 might be needed. In order so make this easy, all the exported functions have
97 PCRE2_CALL_CONVENTION just before their names. It is rarely needed; if not
98 set, we ensure here that it has no effect. */
99 
100 #ifndef PCRE2_CALL_CONVENTION
101 #define PCRE2_CALL_CONVENTION
102 #endif
103 
104 /* Table to translate PCRE2 compile time error codes into POSIX error codes.
105 Only a few PCRE2 errors with a value greater than 23 turn into special POSIX
106 codes: most go to REG_BADPAT. The second table lists, in pairs, those that
107 don't. */
108 
109 static const int eint1[] = {
110   0,           /* No error */
111   REG_EESCAPE, /* \ at end of pattern */
112   REG_EESCAPE, /* \c at end of pattern */
113   REG_EESCAPE, /* unrecognized character follows \ */
114   REG_BADBR,   /* numbers out of order in {} quantifier */
115   /* 5 */
116   REG_BADBR,   /* number too big in {} quantifier */
117   REG_EBRACK,  /* missing terminating ] for character class */
118   REG_ECTYPE,  /* invalid escape sequence in character class */
119   REG_ERANGE,  /* range out of order in character class */
120   REG_BADRPT,  /* nothing to repeat */
121   /* 10 */
122   REG_ASSERT,  /* internal error: unexpected repeat */
123   REG_BADPAT,  /* unrecognized character after (? or (?- */
124   REG_BADPAT,  /* POSIX named classes are supported only within a class */
125   REG_BADPAT,  /* POSIX collating elements are not supported */
126   REG_EPAREN,  /* missing ) */
127   /* 15 */
128   REG_ESUBREG, /* reference to non-existent subpattern */
129   REG_INVARG,  /* pattern passed as NULL */
130   REG_INVARG,  /* unknown compile-time option bit(s) */
131   REG_EPAREN,  /* missing ) after (?# comment */
132   REG_ESIZE,   /* parentheses nested too deeply */
133   /* 20 */
134   REG_ESIZE,   /* regular expression too large */
135   REG_ESPACE,  /* failed to get memory */
136   REG_EPAREN,  /* unmatched closing parenthesis */
137   REG_ASSERT   /* internal error: code overflow */
138   };
139 
140 static const int eint2[] = {
141   30, REG_ECTYPE,  /* unknown POSIX class name */
142   32, REG_INVARG,  /* this version of PCRE2 does not have Unicode support */
143   37, REG_EESCAPE, /* PCRE2 does not support \L, \l, \N{name}, \U, or \u */
144   56, REG_INVARG,  /* internal error: unknown newline setting */
145 };
146 
147 /* Table of texts corresponding to POSIX error codes */
148 
149 static const char *const pstring[] = {
150   "",                                /* Dummy for value 0 */
151   "internal error",                  /* REG_ASSERT */
152   "invalid repeat counts in {}",     /* BADBR      */
153   "pattern error",                   /* BADPAT     */
154   "? * + invalid",                   /* BADRPT     */
155   "unbalanced {}",                   /* EBRACE     */
156   "unbalanced []",                   /* EBRACK     */
157   "collation error - not relevant",  /* ECOLLATE   */
158   "bad class",                       /* ECTYPE     */
159   "bad escape sequence",             /* EESCAPE    */
160   "empty expression",                /* EMPTY      */
161   "unbalanced ()",                   /* EPAREN     */
162   "bad range inside []",             /* ERANGE     */
163   "expression too big",              /* ESIZE      */
164   "failed to get memory",            /* ESPACE     */
165   "bad back reference",              /* ESUBREG    */
166   "bad argument",                    /* INVARG     */
167   "match failed"                     /* NOMATCH    */
168 };
169 
170 
171 
172 
173 /*************************************************
174 *          Translate error code to string        *
175 *************************************************/
176 
177 PCRE2POSIX_EXP_DEFN size_t PCRE2_CALL_CONVENTION
regerror(int errcode,const regex_t * preg,char * errbuf,size_t errbuf_size)178 regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
179 {
180 int used;
181 const char *message;
182 
183 message = (errcode <= 0 || errcode >= (int)(sizeof(pstring)/sizeof(char *)))?
184   "unknown error code" : pstring[errcode];
185 
186 if (preg != NULL && (int)preg->re_erroffset != -1)
187   {
188   used = snprintf(errbuf, errbuf_size, "%s at offset %-6d", message,
189     (int)preg->re_erroffset);
190   }
191 else
192   {
193   used = snprintf(errbuf, errbuf_size, "%s", message);
194   }
195 
196 return used + 1;
197 }
198 
199 
200 
201 
202 /*************************************************
203 *           Free store held by a regex           *
204 *************************************************/
205 
206 PCRE2POSIX_EXP_DEFN void PCRE2_CALL_CONVENTION
regfree(regex_t * preg)207 regfree(regex_t *preg)
208 {
209 pcre2_match_data_free(preg->re_match_data);
210 pcre2_code_free(preg->re_pcre2_code);
211 }
212 
213 
214 
215 
216 /*************************************************
217 *            Compile a regular expression        *
218 *************************************************/
219 
220 /*
221 Arguments:
222   preg        points to a structure for recording the compiled expression
223   pattern     the pattern to compile
224   cflags      compilation flags
225 
226 Returns:      0 on success
227               various non-zero codes on failure
228 */
229 
230 PCRE2POSIX_EXP_DEFN int PCRE2_CALL_CONVENTION
regcomp(regex_t * preg,const char * pattern,int cflags)231 regcomp(regex_t *preg, const char *pattern, int cflags)
232 {
233 PCRE2_SIZE erroffset;
234 int errorcode;
235 int options = 0;
236 int re_nsub = 0;
237 
238 if ((cflags & REG_ICASE) != 0)    options |= PCRE2_CASELESS;
239 if ((cflags & REG_NEWLINE) != 0)  options |= PCRE2_MULTILINE;
240 if ((cflags & REG_DOTALL) != 0)   options |= PCRE2_DOTALL;
241 if ((cflags & REG_UTF) != 0)      options |= PCRE2_UTF;
242 if ((cflags & REG_UCP) != 0)      options |= PCRE2_UCP;
243 if ((cflags & REG_UNGREEDY) != 0) options |= PCRE2_UNGREEDY;
244 
245 preg->re_cflags = cflags;
246 preg->re_pcre2_code = pcre2_compile((PCRE2_SPTR)pattern, PCRE2_ZERO_TERMINATED,
247    options, &errorcode, &erroffset, NULL);
248 preg->re_erroffset = erroffset;
249 
250 if (preg->re_pcre2_code == NULL)
251   {
252   unsigned int i;
253 
254   /* A negative value is a UTF error; otherwise all error codes are greater
255   than COMPILE_ERROR_BASE, but check, just in case. */
256 
257   if (errorcode < COMPILE_ERROR_BASE) return REG_BADPAT;
258   errorcode -= COMPILE_ERROR_BASE;
259 
260   if (errorcode < (int)(sizeof(eint1)/sizeof(const int)))
261     return eint1[errorcode];
262   for (i = 0; i < sizeof(eint2)/(2*sizeof(const int)); i += 2)
263     if (errorcode == eint2[i]) return eint2[i+1];
264   return REG_BADPAT;
265   }
266 
267 (void)pcre2_pattern_info((const pcre2_code *)preg->re_pcre2_code,
268   PCRE2_INFO_CAPTURECOUNT, &re_nsub);
269 preg->re_nsub = (size_t)re_nsub;
270 preg->re_match_data = pcre2_match_data_create(re_nsub + 1, NULL);
271 
272 if (preg->re_match_data == NULL)
273   {
274   pcre2_code_free(preg->re_pcre2_code);
275   return REG_ESPACE;
276   }
277 
278 return 0;
279 }
280 
281 
282 
283 /*************************************************
284 *              Match a regular expression        *
285 *************************************************/
286 
287 /* A suitable match_data block, large enough to hold all possible captures, was
288 obtained when the pattern was compiled, to save having to allocate and free it
289 for each match. If REG_NOSUB was specified at compile time, the
290 PCRE_NO_AUTO_CAPTURE flag will be set. When this is the case, the nmatch and
291 pmatch arguments are ignored, and the only result is yes/no/error. */
292 
293 PCRE2POSIX_EXP_DEFN int PCRE2_CALL_CONVENTION
regexec(const regex_t * preg,const char * string,size_t nmatch,regmatch_t pmatch[],int eflags)294 regexec(const regex_t *preg, const char *string, size_t nmatch,
295   regmatch_t pmatch[], int eflags)
296 {
297 int rc, so, eo;
298 int options = 0;
299 pcre2_match_data *md = (pcre2_match_data *)preg->re_match_data;
300 
301 if ((eflags & REG_NOTBOL) != 0) options |= PCRE2_NOTBOL;
302 if ((eflags & REG_NOTEOL) != 0) options |= PCRE2_NOTEOL;
303 if ((eflags & REG_NOTEMPTY) != 0) options |= PCRE2_NOTEMPTY;
304 
305 ((regex_t *)preg)->re_erroffset = (size_t)(-1);  /* Only has meaning after compile */
306 
307 /* When REG_NOSUB was specified, or if no vector has been passed in which to
308 put captured strings, ensure that nmatch is zero. This will stop any attempt to
309 write to pmatch. */
310 
311 if ((preg->re_cflags & REG_NOSUB) != 0 || pmatch == NULL) nmatch = 0;
312 
313 /* REG_STARTEND is a BSD extension, to allow for non-NUL-terminated strings.
314 The man page from OS X says "REG_STARTEND affects only the location of the
315 string, not how it is matched". That is why the "so" value is used to bump the
316 start location rather than being passed as a PCRE2 "starting offset". */
317 
318 if ((eflags & REG_STARTEND) != 0)
319   {
320   if (pmatch == NULL) return REG_INVARG;
321   so = pmatch[0].rm_so;
322   eo = pmatch[0].rm_eo;
323   }
324 else
325   {
326   so = 0;
327   eo = (int)strlen(string);
328   }
329 
330 rc = pcre2_match((const pcre2_code *)preg->re_pcre2_code,
331   (PCRE2_SPTR)string + so, (eo - so), 0, options, md, NULL);
332 
333 /* Successful match */
334 
335 if (rc >= 0)
336   {
337   size_t i;
338   PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(md);
339   if ((size_t)rc > nmatch) rc = (int)nmatch;
340   for (i = 0; i < (size_t)rc; i++)
341     {
342     pmatch[i].rm_so = ovector[i*2];
343     pmatch[i].rm_eo = ovector[i*2+1];
344     }
345   for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;
346   return 0;
347   }
348 
349 /* Unsuccessful match */
350 
351 if (rc <= PCRE2_ERROR_UTF8_ERR1 && rc >= PCRE2_ERROR_UTF8_ERR21)
352   return REG_INVARG;
353 
354 switch(rc)
355   {
356   default: return REG_ASSERT;
357   case PCRE2_ERROR_BADMODE: return REG_INVARG;
358   case PCRE2_ERROR_BADMAGIC: return REG_INVARG;
359   case PCRE2_ERROR_BADOPTION: return REG_INVARG;
360   case PCRE2_ERROR_BADUTFOFFSET: return REG_INVARG;
361   case PCRE2_ERROR_MATCHLIMIT: return REG_ESPACE;
362   case PCRE2_ERROR_NOMATCH: return REG_NOMATCH;
363   case PCRE2_ERROR_NOMEMORY: return REG_ESPACE;
364   case PCRE2_ERROR_NULL: return REG_INVARG;
365   }
366 }
367 
368 /* End of pcre2posix.c */
369