1/*************************************************
2*      Perl-Compatible Regular Expressions       *
3*************************************************/
4
5/*
6This is a library of functions to support regular expressions whose syntax
7and semantics are as close as possible to those of the Perl 5 language. See
8the file Tech.Notes for some information on the internals.
9
10This module is a wrapper that provides a POSIX API to the underlying PCRE
11functions.
12
13Written by: Philip Hazel <ph10@cam.ac.uk>
14
15           Copyright (c) 1997-2004 University of Cambridge
16
17-----------------------------------------------------------------------------
18Redistribution and use in source and binary forms, with or without
19modification, are permitted provided that the following conditions are met:
20
21    * Redistributions of source code must retain the above copyright notice,
22      this list of conditions and the following disclaimer.
23
24    * Redistributions in binary form must reproduce the above copyright
25      notice, this list of conditions and the following disclaimer in the
26      documentation and/or other materials provided with the distribution.
27
28    * Neither the name of the University of Cambridge nor the names of its
29      contributors may be used to endorse or promote products derived from
30      this software without specific prior written permission.
31
32THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
33AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
36LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
37CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
38SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
39INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
40CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42POSSIBILITY OF SUCH DAMAGE.
43-----------------------------------------------------------------------------
44*/
45
46#include "httpd.h"
47#include "apr_strings.h"
48#include "pcre.h"
49
50#define APR_WANT_STRFUNC
51#include "apr_want.h"
52
53#ifndef POSIX_MALLOC_THRESHOLD
54#define POSIX_MALLOC_THRESHOLD (10)
55#endif
56
57/* Table of error strings corresponding to POSIX error codes; must be
58 * kept in synch with include/ap_regex.h's AP_REG_E* definitions. */
59
60static const char *const pstring[] = {
61  "",                                /* Dummy for value 0 */
62  "internal error",                  /* AP_REG_ASSERT */
63  "failed to get memory",            /* AP_REG_ESPACE */
64  "bad argument",                    /* AP_REG_INVARG */
65  "match failed"                     /* AP_REG_NOMATCH */
66};
67
68AP_DECLARE(apr_size_t) ap_regerror(int errcode, const ap_regex_t *preg,
69                                   char *errbuf, apr_size_t errbuf_size)
70{
71const char *message, *addmessage;
72apr_size_t length, addlength;
73
74message = (errcode >= (int)(sizeof(pstring)/sizeof(char *)))?
75  "unknown error code" : pstring[errcode];
76length = strlen(message) + 1;
77
78addmessage = " at offset ";
79addlength = (preg != NULL && (int)preg->re_erroffset != -1)?
80  strlen(addmessage) + 6 : 0;
81
82if (errbuf_size > 0)
83  {
84  if (addlength > 0 && errbuf_size >= length + addlength)
85      apr_snprintf(errbuf, sizeof errbuf,
86                   "%s%s%-6d", message, addmessage, (int)preg->re_erroffset);
87  else
88    {
89    strncpy(errbuf, message, errbuf_size - 1);
90    errbuf[errbuf_size-1] = 0;
91    }
92  }
93
94return length + addlength;
95}
96
97
98
99
100/*************************************************
101*           Free store held by a regex           *
102*************************************************/
103
104AP_DECLARE(void) ap_regfree(ap_regex_t *preg)
105{
106(pcre_free)(preg->re_pcre);
107}
108
109
110
111
112/*************************************************
113*            Compile a regular expression        *
114*************************************************/
115
116/*
117Arguments:
118  preg        points to a structure for recording the compiled expression
119  pattern     the pattern to compile
120  cflags      compilation flags
121
122Returns:      0 on success
123              various non-zero codes on failure
124*/
125
126AP_DECLARE(int) ap_regcomp(ap_regex_t *preg, const char *pattern, int cflags)
127{
128const char *errorptr;
129int erroffset;
130int options = 0;
131int nsub;
132
133if ((cflags & AP_REG_ICASE) != 0) options |= PCRE_CASELESS;
134if ((cflags & AP_REG_NEWLINE) != 0) options |= PCRE_MULTILINE;
135
136preg->re_pcre = pcre_compile(pattern, options, &errorptr, &erroffset, NULL);
137preg->re_erroffset = erroffset;
138
139if (preg->re_pcre == NULL) return AP_REG_INVARG;
140
141pcre_fullinfo((const pcre *)preg->re_pcre, NULL,
142              PCRE_INFO_CAPTURECOUNT, &nsub);
143preg->re_nsub = (apr_size_t)nsub;
144return 0;
145}
146
147
148
149
150/*************************************************
151*              Match a regular expression        *
152*************************************************/
153
154/* Unfortunately, PCRE requires 3 ints of working space for each captured
155substring, so we have to get and release working store instead of just using
156the POSIX structures as was done in earlier releases when PCRE needed only 2
157ints. However, if the number of possible capturing brackets is small, use a
158block of store on the stack, to reduce the use of malloc/free. The threshold is
159in a macro that can be changed at configure time. */
160
161AP_DECLARE(int) ap_regexec(const ap_regex_t *preg, const char *string,
162                           apr_size_t nmatch, ap_regmatch_t pmatch[],
163                           int eflags)
164{
165int rc;
166int options = 0;
167int *ovector = NULL;
168int small_ovector[POSIX_MALLOC_THRESHOLD * 3];
169int allocated_ovector = 0;
170
171if ((eflags & AP_REG_NOTBOL) != 0) options |= PCRE_NOTBOL;
172if ((eflags & AP_REG_NOTEOL) != 0) options |= PCRE_NOTEOL;
173
174((ap_regex_t *)preg)->re_erroffset = (apr_size_t)(-1);  /* Only has meaning after compile */
175
176if (nmatch > 0)
177  {
178  if (nmatch <= POSIX_MALLOC_THRESHOLD)
179    {
180    ovector = &(small_ovector[0]);
181    }
182  else
183    {
184    ovector = (int *)malloc(sizeof(int) * nmatch * 3);
185    if (ovector == NULL) return AP_REG_ESPACE;
186    allocated_ovector = 1;
187    }
188  }
189
190rc = pcre_exec((const pcre *)preg->re_pcre, NULL, string, (int)strlen(string),
191  0, options, ovector, nmatch * 3);
192
193if (rc == 0) rc = nmatch;    /* All captured slots were filled in */
194
195if (rc >= 0)
196  {
197  apr_size_t i;
198  for (i = 0; i < (apr_size_t)rc; i++)
199    {
200    pmatch[i].rm_so = ovector[i*2];
201    pmatch[i].rm_eo = ovector[i*2+1];
202    }
203  if (allocated_ovector) free(ovector);
204  for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;
205  return 0;
206  }
207
208else
209  {
210  if (allocated_ovector) free(ovector);
211  switch(rc)
212    {
213    case PCRE_ERROR_NOMATCH: return AP_REG_NOMATCH;
214    case PCRE_ERROR_NULL: return AP_REG_INVARG;
215    case PCRE_ERROR_BADOPTION: return AP_REG_INVARG;
216    case PCRE_ERROR_BADMAGIC: return AP_REG_INVARG;
217    case PCRE_ERROR_UNKNOWN_NODE: return AP_REG_ASSERT;
218    case PCRE_ERROR_NOMEMORY: return AP_REG_ESPACE;
219#ifdef PCRE_ERROR_MATCHLIMIT
220    case PCRE_ERROR_MATCHLIMIT: return AP_REG_ESPACE;
221#endif
222#ifdef PCRE_ERROR_BADUTF8
223    case PCRE_ERROR_BADUTF8: return AP_REG_INVARG;
224#endif
225#ifdef PCRE_ERROR_BADUTF8_OFFSET
226    case PCRE_ERROR_BADUTF8_OFFSET: return AP_REG_INVARG;
227#endif
228    default: return AP_REG_ASSERT;
229    }
230  }
231}
232
233/* End of pcreposix.c */
234