-const char pcrs_rcs[] = "$Id: pcrs.c,v 1.9 2001/07/18 17:27:00 oes Exp $";
+const char pcrs_rcs[] = "$Id: pcrs.c,v 1.11 2001/08/15 15:26:24 oes Exp $";
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $
*
* Purpose : pcrs is a supplement to the brilliant pcre library by Philip
- * Hazel (ph10@cam.ac.uk) and adds Perl-style substitution. That
+ * Hazel <ph10@cam.ac.uk> and adds Perl-style substitution. That
* is, it mimics Perl's 's' operator.
*
* Currently, there's no documentation besides comments and the
- * source itself ;-)
+ * source itself :-(
*
* Note: In addition to perl's options, 'U' for ungreedy and 'T'
* for trivial (i.e.: ignore backrefs in the substitute) are
*
* Revisions :
* $Log: pcrs.c,v $
+ * Revision 1.10 2001/08/05 13:13:11 jongfoster
+ * Making parameters "const" where possible.
+ *
* Revision 1.9 2001/07/18 17:27:00 oes
* Changed interface; Cosmetics
*
* - Removed create_pcrs_job() which was useless
* - Fixed a bug in pcrs_execute
* - Success flag is now handled by pcrs instead of user
- * - Removed logentry from cancelled commit
*
* Revision 1.6 2001/06/03 19:12:45 oes
* added FIXME
*
* Revision 1.5 2001/05/29 09:50:24 jongfoster
- * Unified blocklist/imagelist/permissionslist.
- * File format is still under discussion, but the internal changes
- * are (mostly) done.
- *
- * Also modified interceptor behaviour:
- * - We now intercept all URLs beginning with one of the following
- * prefixes (and *only* these prefixes):
- * * http://i.j.b/
- * * http://ijbswa.sf.net/config/
- * * http://ijbswa.sourceforge.net/config/
- * - New interceptors "home page" - go to http://i.j.b/ to see it.
- * - Internal changes so that intercepted and fast redirect pages
- * are not replaced with an image.
- * - Interceptors now have the option to send a binary page direct
- * to the client. (i.e. ijb-send-banner uses this)
- * - Implemented show-url-info interceptor. (Which is why I needed
- * the above interceptors changes - a typical URL is
- * "http://i.j.b/show-url-info?url=www.somesite.com/banner.gif".
- * The previous mechanism would not have intercepted that, and
- * if it had been intercepted then it then it would have replaced
- * it with an image.)
+ * (Fixed one int -> size_t)
*
* Revision 1.4 2001/05/25 14:12:40 oes
* Fixed bug: Empty substitutes now detected
*
* Revision 1.2 2001/05/22 18:46:04 oes
*
- * - Enabled filtering banners by size rather than URL
- * by adding patterns that replace all standard banner
- * sizes with the "Junkbuster" gif to the re_filterfile
- *
- * - Enabled filtering WebBugs by providing a pattern
- * which kills all 1x1 images
- *
- * - Added support for PCRE_UNGREEDY behaviour to pcrs,
+ * Added support for PCRE_UNGREEDY behaviour to pcrs,
* which is selected by the (nonstandard and therefore
* capital) letter 'U' in the option string.
* It causes the quantifiers to be ungreedy by default.
* Appending a ? turns back to greedy (!).
*
- * - Added a new interceptor ijb-send-banner, which
- * sends back the "Junkbuster" gif. Without imagelist or
- * MSIE detection support, or if tinygif = 1, or the
- * URL isn't recognized as an imageurl, a lame HTML
- * explanation is sent instead.
- *
- * - Added new feature, which permits blocking remote
- * script redirects and firing back a local redirect
- * to the browser.
- * The feature is conditionally compiled, i.e. it
- * can be disabled with --disable-fast-redirects,
- * plus it must be activated by a "fast-redirects"
- * line in the config file, has its own log level
- * and of course wants to be displayed by show-proxy-args
- * Note: Boy, all the #ifdefs in 1001 locations and
- * all the fumbling with configure.in and acconfig.h
- * were *way* more work than the feature itself :-(
- *
- * - Because a generic redirect template was needed for
- * this, tinygif = 3 now uses the same.
- *
- * - Moved GIFs, and other static HTTP response templates
- * to project.h
- *
- * - Some minor fixes
- *
- * - Removed some >400 CRs again (Jon, you really worked
- * a lot! ;-)
- *
* Revision 1.1.1.1 2001/05/15 13:59:02 oes
* Initial import of version 2.9.3 source tree
*
#include <pcre.h>
#include <string.h>
#include "pcrs.h"
+#include <stdio.h>
const char pcrs_h_rcs[] = PCRS_H_VERSION;
/*********************************************************************
*
- * Function : pcrs_compile_perl_options
+ * Function : pcrs_parse_perl_options
*
* Description : This function parses a string containing the options to
* Perl's s/// operator. It returns an integer that is the
* Returns : option integer suitable for pcre
*
*********************************************************************/
-int pcrs_compile_perl_options(const char *optstring, int *flags)
+int pcrs_parse_perl_options(const char *optstring, int *flags)
{
size_t i;
int rc = 0;
{
switch(optstring[i])
{
- case 'e': break;
+ case 'e': break; /* ToDo ;-) */
case 'g': *flags |= PCRS_GLOBAL; break;
case 'i': rc |= PCRE_CASELESS; break;
case 'm': rc |= PCRE_MULTILINE; break;
* Parameters :
* 1 : replacement = replacement part of s/// operator
* in perl syntax
- * 2 : errptr = pointer to an integer in which error
+ * 2 : trivialflag = Flag that causes backreferences to be
+ * ignored.
+ * 3 : capturecount = Number of capturing subpatterns in
+ * the pattern. Needed for $+ handling.
+ * 4 : errptr = pointer to an integer in which error
* conditions can be returned.
*
* Returns : pcrs_substitute data structure, or NULL if an
* the reason.
*
*********************************************************************/
-pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int *errptr)
+pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr)
{
- int length, i, k = 0, l = 0, quoted = 0, idx;
- char *text, *num_ptr, *numbers = "0123456789";
+ int length, i, k, l, quoted;
+ char *text;
pcrs_substitute *r;
- r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute));
- if (r == NULL) return NULL;
- memset(r, '\0', sizeof(pcrs_substitute));
+ i = k = l = quoted = 0;
- text = strdup(replacement); /* must be free()d by caller */
- if (text == NULL)
+ /*
+ * Get memory or fail
+ */
+ if (NULL == (r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute))))
{
*errptr = PCRS_ERR_NOMEM;
- free(r);
return NULL;
}
+ memset(r, '\0', sizeof(pcrs_substitute));
length = strlen(replacement);
+ if (NULL == (text = (char *)malloc(length + 1)))
+ {
+ free(r);
+ *errptr = PCRS_ERR_NOMEM;
+ return NULL;
+ }
+ memset(r, '\0', length + 1);
+
+
+ /*
+ * In trivial mode, just copy the substitute text
+ */
if (trivialflag)
{
- k = length;
+ text = strncpy(text, replacement, length + 1);
+ k = length;
}
+
+ /*
+ * Else, parse, cut out and record all backreferences
+ */
else
{
- for (i=0; i < length; i++)
+ while(i < length)
{
- /* Backslash treatment */
+ /* Quoting */
if (replacement[i] == '\\')
{
if (quoted)
{
- text[k++] = replacement[i];
+ text[k++] = replacement[i++];
quoted = 0;
}
else
{
quoted = 1;
+ i++;
}
continue;
}
- /* Dollar treatment */
+ /* Backreferences */
if (replacement[i] == '$' && !quoted && i < length - 1)
{
- if (strchr("0123456789&", replacement[i + 1]) == NULL)
+ char *symbol, symbols[] = "'`+&";
+ r->block_length[l] = k - r->block_offset[l];
+
+ /* Numerical backreferences */
+ if (isdigit(replacement[i + 1]))
{
- text[k++] = replacement[i];
+ while (i < length && isdigit(replacement[++i]))
+ {
+ r->backref[l] = r->backref[l] * 10 + replacement[i] - 48;
+ }
}
- else
+
+ /* Symbolic backreferences: */
+ else if (NULL != (symbol = strchr(symbols, replacement[i + 1])))
{
- r->block_length[l] = k - r->block_offset[l];
- r->backref[l] = 0;
- if (replacement[i + 1] != '&')
+
+ if (symbol - symbols == 2) /* $+ */
+ {
+ r->backref[l] = capturecount;
+ }
+ else if (symbol - symbols == 3) /* $& */
+ {
+ r->backref[l] = 0;
+ }
+ else /* $' or $` */
{
- while ((num_ptr = strchr(numbers, replacement[++i])) != NULL && i < length)
- {
- idx = num_ptr - numbers;
- r->backref[l] = r->backref[l] * 10 + idx;
- }
- i--;
+ r->backref[l] = PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols);
}
- else
- i++;
- if (r->backref[l] < PCRS_MAX_SUBMATCHES)
- r->backref_count[r->backref[l]] += 1;
- l++;
- r->block_offset[l] = k;
+ i += 2;
+ }
+
+ /* Invalid backref -> plain '$' */
+ else
+ {
+ goto plainchar;
+ }
+
+ /* Valid and in range? -> record */
+ if (r->backref[l] < PCRS_MAX_SUBMATCHES + 2)
+ {
+ r->backref_count[r->backref[l]] += 1;
+ r->block_offset[++l] = k;
}
continue;
}
-
- /* Plain char treatment */
- text[k++] = replacement[i];
+
+plainchar:
+ /* Plain chars are copied */
+ text[k++] = replacement[i++];
quoted = 0;
}
} /* -END- if (!trivialflag) */
- text[k] = '\0';
+ /*
+ * Finish & return
+ */
r->text = text;
r->backrefs = l;
r->block_length[l] = k - r->block_offset[l];
+
return r;
}
* Function : pcrs_free_job
*
* Description : Frees the memory used by a pcrs_job struct and its
- * dependant structures. Returns a pointer to the next
- * job, if there was any, or NULL otherwise.
+ * dependant structures.
*
* Parameters :
* 1 : job = pointer to the pcrs_job structure to be freed
}
+
/*********************************************************************
*
* Function : pcrs_free_joblist
l = -1;
break;
}
- tokens[0][k++] = '\0';
+ tokens[0][k++] = '\0';
tokens[++l] = tokens[0] + k;
continue;
}
quoted = FALSE;
}
-
/*
* Syntax error ?
*/
{
pcrs_job *newjob;
int flags;
+ int capturecount;
const char *error;
/*
* Evaluate the options
*/
- newjob->options = pcrs_compile_perl_options(options, &flags);
+ newjob->options = pcrs_parse_perl_options(options, &flags);
newjob->flags = flags;
}
+ /*
+ * Determine the number of capturing subpatterns.
+ * This is needed for handling $+ in the substitute.
+ */
+ if (0 > (*errptr = pcre_fullinfo(newjob->pattern, newjob->hints, PCRE_INFO_CAPTURECOUNT, &capturecount)))
+ {
+ pcrs_free_job(newjob);
+ return NULL;
+ }
+
+
/*
* Compile the substitute
*/
- if (NULL == (newjob->substitute = pcrs_compile_replacement(substitute, newjob->flags & PCRS_TRIVIAL, errptr)))
+ if (NULL == (newjob->substitute = pcrs_compile_replacement(substitute, newjob->flags & PCRS_TRIVIAL, capturecount, errptr)))
{
pcrs_free_job(newjob);
return NULL;
* INCLUDING the terminating zero, if string!
* 4 : result = char** for returning the result
* 5 : result_length = int* for returning the result's length
+ * 6 : max_matches = maximum number of matches in global searches
*
* Returns : the number of substitutions that were made. May be > 1
* if job->flags contained PCRS_GLOBAL
offset, i, k,
matches_found,
newsize,
- submatches;
- pcrs_match matches[PCRS_MAX_MATCHES];
+ submatches,
+ max_matches = PCRS_MAX_MATCH_INIT;
+ pcrs_match *matches, *dummy;
char *result_offset;
offset = i = k = 0;
/*
- * Sanity check
+ * Sanity check & memory allocation
*/
if (job == NULL || job->pattern == NULL || job->substitute == NULL)
{
return(PCRS_ERR_BADJOB);
}
-
+ if (NULL == (matches = (pcrs_match *)malloc(max_matches * sizeof(pcrs_match))))
+ {
+ *result = NULL;
+ return(PCRS_ERR_NOMEM);
+ }
+ memset(matches, '\0', max_matches * sizeof(pcrs_match));
+
+
/*
* Find the pattern and calculate the space
- * requirements for the result (newsize)
+ * requirements for the result
*/
newsize=subject_length;
{
job->flags |= PCRS_SUCCESS;
matches[i].submatches = submatches;
+
for (k=0; k < submatches; k++)
{
matches[i].submatch_offset[k] = offsets[2 * k];
/* plus replacement text size minus match text size */
newsize += strlen(job->substitute->text) - matches[i].submatch_length[0];
+ /* chunk before match */
+ matches[i].submatch_offset[PCRS_MAX_SUBMATCHES] = 0;
+ matches[i].submatch_length[PCRS_MAX_SUBMATCHES] = offsets[0];
+ newsize += offsets[0] * job->substitute->backref_count[PCRS_MAX_SUBMATCHES];
+
+ /* chunk after match */
+ matches[i].submatch_offset[PCRS_MAX_SUBMATCHES + 1] = offsets[1];
+ matches[i].submatch_length[PCRS_MAX_SUBMATCHES + 1] = subject_length - offsets[1] - 1;
+ newsize += (subject_length - offsets[1])* job->substitute->backref_count[PCRS_MAX_SUBMATCHES + 1];
+
/* Non-global search or limit reached? */
- if (++i >= PCRS_MAX_MATCHES || !(job->flags & PCRS_GLOBAL) ) break;
+ if (!(job->flags & PCRS_GLOBAL)) break;
+
+ /* Storage for matches exhausted? -> Extend! */
+ if (++i >= max_matches)
+ {
+ max_matches *= PCRS_MAX_MATCH_GROW;
+ if (NULL == (dummy = (pcrs_match *)realloc(matches, max_matches * sizeof(pcrs_match))))
+ {
+ free(matches);
+ *result = NULL;
+ return(PCRS_ERR_NOMEM);
+ }
+ matches = dummy;
+ }
/* Don't loop on empty matches */
if (offsets[1] == offset)
offset = offsets[1];
}
/* Pass pcre error through if failiure */
- if (submatches < -1) return submatches;
+ if (submatches < -1)
+ {
+ free(matches);
+ return submatches;
+ }
matches_found = i;
*/
if ((*result = (char *)malloc(newsize)) == NULL) /* must be free()d by caller */
{
+ free(matches);
return PCRS_ERR_NOMEM;
}
/* ..plus, if it's not the last chunk, i.e.: There *is* a backref.. */
if (k != job->substitute->backrefs
/* ..in legal range.. */
- && job->substitute->backref[k] <= PCRS_MAX_SUBMATCHES
+ && job->substitute->backref[k] < PCRS_MAX_SUBMATCHES + 2
/* ..and referencing a nonempty match.. */
&& matches[i].submatch_length[job->substitute->backref[k]] > 0)
{
memcpy(result_offset, subject + offset, subject_length - offset);
*result_length = newsize;
+ free(matches);
return matches_found;
}
projects / privoxy.git / commitdiff