-const char pcrs_rcs[] = "$Id: pcrs.c,v 1.22 2006/12/24 17:34:20 fabiankeil Exp $";
-
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $
* <ph10@cam.ac.uk> and adds Perl-style substitution. That
* is, it mimics Perl's 's' operator. See pcrs(3) for details.
*
+ * WARNING: This file contains additional functions and bug
+ * fixes that aren't part of the latest official pcrs package
+ * (which apparently is no longer maintained).
*
* Copyright : Written and Copyright (C) 2000, 2001 by Andreas S. Oesterhelt
* <andreas@oesterhelt.org>
*
- * This program is free software; you can redistribute it
- * and/or modify it under the terms of the GNU Lesser
- * General Public License (LGPL), version 2.1, which should
- * be included in this distribution (see LICENSE.txt), with
- * the exception that the permission to replace that license
- * with the GNU General Public License (GPL) given in section
- * 3 is restricted to version 2 of the GPL.
+ * Copyright (C) 2006, 2007 Fabian Keil <fk@fabiankeil.de>
+ *
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General
+ * Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at
+ * your option) any later version.
*
* This program is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A
- * PARTICULAR PURPOSE. See the license for more details.
+ * PARTICULAR PURPOSE. See the GNU General Public
+ * License for more details.
*
- * The GNU Lesser General Public License should be included
- * with this file. If not, you can view it at
- * http://www.gnu.org/licenses/lgpl.html
+ * The GNU General Public License should be included with
+ * this file. If not, you can view it at
+ * http://www.gnu.org/copyleft/gpl.html
* or write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
- * Revisions :
- * $Log: pcrs.c,v $
- * Revision 1.22 2006/12/24 17:34:20 fabiankeil
- * Add pcrs_strerror() message for PCRE_ERROR_MATCHLIMIT
- * and give a hint why an error code might be unknown.
- *
- * Catch NULL subjects early in pcrs_execute().
- *
- * Revision 1.21 2006/07/18 14:48:47 david__schmidt
- * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
- * with what was really the latest development (the v_3_0_branch branch)
- *
- * Revision 1.19.2.4 2005/05/07 21:50:55 david__schmidt
- * A few memory leaks plugged (mostly on error paths)
- *
- * Revision 1.19.2.3 2003/12/04 12:32:45 oes
- * Append a trailing nullbyte to result to facilitate string processing
- *
- * Revision 1.19.2.2 2002/10/08 16:22:28 oes
- * Bugfix: Need to check validity of backreferences explicitly,
- * because when max_matches are reached and matches is expanded,
- * realloc() does not zero the memory. Fixes Bug # 606227
- *
- * Revision 1.19.2.1 2002/08/10 11:23:40 oes
- * Include prce.h via project.h, where the appropriate
- * source will have been selected
- *
- * Revision 1.19 2002/03/08 14:47:48 oes
- * Cosmetics
- *
- * Revision 1.18 2002/03/08 14:17:14 oes
- * Fixing -Wconversion warnings
- *
- * Revision 1.17 2002/03/08 13:45:48 oes
- * Hiding internal functions
- *
- * Revision 1.16 2001/11/30 21:32:14 jongfoster
- * Fixing signed/unsigned comparison (Andreas please check this!)
- * One tab->space
- *
- * Revision 1.15 2001/09/20 16:11:06 steudten
- *
- * Add casting for some string functions.
- *
- * Revision 1.14 2001/09/09 21:41:57 oes
- * Fixing yet another silly bug
- *
- * Revision 1.13 2001/09/06 14:05:59 oes
- * Fixed silly bug
- *
- * Revision 1.12 2001/08/18 11:35:00 oes
- * - Introduced pcrs_strerror()
- * - made some NULL arguments non-fatal
- * - added support for \n \r \e \b \t \f \a \0 in substitute
- * - made quoting adhere to standard rules
- * - added warning for bad backrefs
- * - added pcrs_execute_list()
- * - fixed comments
- * - bugfix & cosmetics
- *
- * Revision 1.11 2001/08/15 15:32:03 oes
- * - Added support for Perl's special variables $+, $' and $`
- * - Improved the substitute parser
- * - Replaced the hard limit for the maximum number of matches
- * by dynamic reallocation
- *
- * 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
- *
- * Revision 1.8 2001/06/29 21:45:41 oes
- * Indentation, CRLF->LF, Tab-> Space
- *
- * Revision 1.7 2001/06/29 13:33:04 oes
- * - Cleaned up, renamed and reordered functions,
- * improved comments
- * - Removed my_strsep
- * - Replaced globalflag with a general flags int
- * that holds PCRS_GLOBAL, PCRS_SUCCESS, and PCRS_TRIVIAL
- * - Introduced trivial option that will prevent pcrs
- * from honouring backreferences in the substitute,
- * which is useful for large substitutes that are
- * red in from somewhere and saves the pain of escaping
- * the backrefs
- * - Introduced convenience function pcrs_free_joblist()
- * - Split pcrs_make_job() into pcrs_compile(), which still
- * takes a complete s/// comand as argument and parses it,
- * and a new function pcrs_make_job, which takes the
- * three separate components. This should make for a
- * much friendlier frontend.
- * - Removed create_pcrs_job() which was useless
- * - Fixed a bug in pcrs_execute
- * - Success flag is now handled by pcrs instead of user
- *
- * Revision 1.6 2001/06/03 19:12:45 oes
- * added FIXME
- *
- * Revision 1.5 2001/05/29 09:50:24 jongfoster
- * (Fixed one int -> size_t)
- *
- * Revision 1.4 2001/05/25 14:12:40 oes
- * Fixed bug: Empty substitutes now detected
- *
- * Revision 1.3 2001/05/25 11:03:55 oes
- * Added sanity check for NULL jobs to pcrs_exec_substitution
- *
- * Revision 1.2 2001/05/22 18:46:04 oes
- *
- * 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 (!).
- *
- * Revision 1.1.1.1 2001/05/15 13:59:02 oes
- * Initial import of version 2.9.3 source tree
- *
- *
*********************************************************************/
-\f
+
+
+#include <string.h>
+#include <ctype.h>
+#include <assert.h>
/*
* Include project.h just so that the right pcre.h gets
*/
#include "project.h"
-#include <string.h>
-#include <ctype.h>
+/* For snprintf only */
+#include "miscutil.h"
+/* For xtoi */
+#include "encode.h"
#include "pcrs.h"
-const char pcrs_h_rcs[] = PCRS_H_VERSION;
-
/*
* Internal prototypes
*/
static int pcrs_parse_perl_options(const char *optstring, int *flags);
static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag,
int capturecount, int *errptr);
+static int is_hex_sequence(const char *sequence);
/*********************************************************************
*
* Function : pcrs_strerror
*
* Description : Return a string describing a given error code.
- *
+ *
* Parameters :
* 1 : error = the error code
*
*********************************************************************/
const char *pcrs_strerror(const int error)
{
- if (error < 0)
+ static char buf[100];
+
+ if (error != 0)
{
switch (error)
{
case PCRE_ERROR_UNKNOWN_NODE: return "(pcre:) Bad node in pattern";
/* Can't happen / not passed: */
- case PCRE_ERROR_NOSUBSTRING: return "(pcre:) Fire in power supply";
+ case PCRE_ERROR_NOSUBSTRING: return "(pcre:) Fire in power supply";
case PCRE_ERROR_NOMATCH: return "(pcre:) Water in power supply";
#ifdef PCRE_ERROR_MATCHLIMIT
case PCRS_ERR_STUDY: return "(pcrs:) PCRE error while studying the pattern";
case PCRS_ERR_BADJOB: return "(pcrs:) Bad job - NULL job, pattern or substitute";
case PCRS_WARN_BADREF: return "(pcrs:) Backreference out of range";
+ case PCRS_WARN_TRUNCATION:
+ return "(pcrs:) At least one variable was too big and has been truncated before compilation";
- /*
+ /*
* XXX: With the exception of PCRE_ERROR_MATCHLIMIT we
* only catch PCRE errors that can happen with our internal
* version. If Privoxy is linked against a newer
* PCRE version all bets are off ...
*/
- default: return "Unknown error. Privoxy out of sync with PCRE?";
+ default:
+ snprintf(buf, sizeof(buf),
+ "Error code %d. For details, check the pcre documentation.",
+ error);
+ return buf;
}
}
/* error >= 0: No error */
* 'T' (trivial) options but pcrs needs them, the corresponding
* flags are set if 'g'or 'T' is encountered.
* Note: The 'T' and 'U' options do not conform to Perl.
- *
+ *
* Parameters :
* 1 : optstring = string with options in perl syntax
* 2 : flags = see description
*
- * Returns : option integer suitable for pcre
+ * Returns : option integer suitable for pcre
*
*********************************************************************/
static int pcrs_parse_perl_options(const char *optstring, int *flags)
case 'o': break;
case 's': rc |= PCRE_DOTALL; break;
case 'x': rc |= PCRE_EXTENDED; break;
+ case 'D': *flags |= PCRS_DYNAMIC; break;
case 'U': rc |= PCRE_UNGREEDY; break;
case 'T': *flags |= PCRS_TRIVIAL; break;
default: break;
}
+#ifdef FUZZ
+/*********************************************************************
+ *
+ * Function : pcrs_compile_fuzzed_replacement
+ *
+ * Description : Wrapper around pcrs_compile_replacement() for
+ * fuzzing purposes.
+ *
+ * Parameters :
+ * 1 : replacement = replacement part of s/// operator
+ * in perl syntax
+ * 2 : errptr = pointer to an integer in which error
+ * conditions can be returned.
+ *
+ * Returns : pcrs_substitute data structure, or NULL if an
+ * error is encountered. In that case, *errptr has
+ * the reason.
+ *
+ *********************************************************************/
+extern pcrs_substitute *pcrs_compile_fuzzed_replacement(const char *replacement, int *errptr)
+{
+ int capturecount = PCRS_MAX_SUBMATCHES; /* XXX: fuzzworthy? */
+ int trivial_flag = 0; /* We don't want to fuzz strncpy() */
+
+ *errptr = 0; /* XXX: Should pcrs_compile_replacement() do this? */
+
+ return pcrs_compile_replacement(replacement, trivial_flag, capturecount, errptr);
+
+}
+#endif
+
+
/*********************************************************************
*
* Function : pcrs_compile_replacement
static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr)
{
int i, k, l, quoted;
- size_t length;
char *text;
pcrs_substitute *r;
-
+#ifndef FUZZ
+ size_t length;
+#else
+ static size_t length;
+#endif
i = k = l = quoted = 0;
/*
return NULL;
}
memset(text, '\0', length + 1);
-
+
/*
* In trivial mode, just copy the substitute text
*/
if (trivialflag)
{
- text = strncpy(text, replacement, length + 1);
+ strlcpy(text, replacement, length + 1);
k = (int)length;
}
}
i++;
}
+ else if (is_hex_sequence(&replacement[i]))
+ {
+ /*
+ * Replace a hex sequence with a single
+ * character with the sequence's ascii value.
+ * e.g.: '\x7e' => '~'
+ */
+ const int ascii_value = xtoi(&replacement[i+2]);
+
+ assert(ascii_value >= 0);
+ assert(ascii_value < 256);
+ text[k++] = (char)ascii_value;
+ i += 4;
+ }
else
{
quoted = 1;
if (replacement[i] == '$' && !quoted && i < (int)(length - 1))
{
char *symbol, symbols[] = "'`+&";
+ if (l >= PCRS_MAX_SUBMATCHES)
+ {
+ freez(text);
+ freez(r);
+ *errptr = PCRS_WARN_BADREF;
+ return NULL;
+ }
r->block_length[l] = (size_t)(k - r->block_offset[l]);
/* Numerical backreferences */
}
if (r->backref[l] > capturecount)
{
+ freez(text);
+ freez(r);
*errptr = PCRS_WARN_BADREF;
+ return NULL;
}
}
/* Symbolic backreferences: */
else if (NULL != (symbol = strchr(symbols, replacement[i + 1])))
{
-
+
if (symbol - symbols == 2) /* $+ */
{
r->backref[l] = capturecount;
}
else /* $' or $` */
{
- r->backref[l] = PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols);
+ r->backref[l] = (int)(PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols));
}
i += 2;
}
goto plainchar;
}
+ assert(r->backref[l] < PCRS_MAX_SUBMATCHES + 2);
/* Valid and in range? -> record */
- if (r->backref[l] < PCRS_MAX_SUBMATCHES + 2)
+ if ((0 <= r->backref[l]) &&
+ (r->backref[l] < PCRS_MAX_SUBMATCHES + 2) &&
+ (l < PCRS_MAX_SUBMATCHES - 1))
{
r->backref_count[r->backref[l]] += 1;
r->block_offset[++l] = k;
}
else
{
+ freez(text);
+ freez(r);
*errptr = PCRS_WARN_BADREF;
- }
+ return NULL;
+ }
continue;
}
-
+
plainchar:
/* Plain chars are copied */
text[k++] = replacement[i++];
*/
r->text = text;
r->backrefs = l;
+ r->length = (size_t)k;
r->block_length[l] = (size_t)(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.
+ * dependent structures.
*
* Parameters :
* 1 : job = pointer to the pcrs_job structure to be freed
*
* Returns : a pointer to the next job, if there was any, or
- * NULL otherwise.
+ * NULL otherwise.
*
*********************************************************************/
pcrs_job *pcrs_free_job(pcrs_job *job)
{
next = job->next;
if (job->pattern != NULL) free(job->pattern);
- if (job->hints != NULL) free(job->hints);
+ if (job->hints != NULL)
+ {
+#ifdef PCRE_CONFIG_JIT
+ pcre_free_study(job->hints);
+#else
+ free(job->hints);
+#endif
+ }
if (job->substitute != NULL)
{
if (job->substitute->text != NULL) free(job->substitute->text);
*********************************************************************/
void pcrs_free_joblist(pcrs_job *joblist)
{
- while ( NULL != (joblist = pcrs_free_job(joblist)) ) {};
+ while (NULL != (joblist = pcrs_free_job(joblist))) {};
return;
*
* Function : pcrs_compile_command
*
- * Description : Parses a string with a Perl-style s/// command,
+ * Description : Parses a string with a Perl-style s/// command,
* calls pcrs_compile, and returns a corresponding
* pcrs_job, or NULL if parsing or compiling the job
* fails.
int i, k, l, quoted = FALSE;
size_t limit;
char delimiter;
- char *tokens[4];
+ char *tokens[4];
pcrs_job *newjob;
-
- i = k = l = 0;
-
+
+ k = l = 0;
+
/*
* Tokenize the perl command
*/
for (i = 0; i <= (int)limit; i++)
{
-
+
if (command[i] == delimiter && !quoted)
{
if (l == 3)
tokens[++l] = tokens[0] + k;
continue;
}
-
+
else if (command[i] == '\\' && !quoted)
{
quoted = TRUE;
free(tokens[0]);
return NULL;
}
-
+
newjob = pcrs_compile(tokens[1], tokens[2], tokens[3], errptr);
free(tokens[0]);
return newjob;
-
+
}
int flags;
int capturecount;
const char *error;
+ int pcre_study_options = 0;
*errptr = 0;
- /*
+ /*
* Handle NULL arguments
*/
if (pattern == NULL) pattern = "";
if (substitute == NULL) substitute = "";
- /*
+ /*
* Get and init memory
*/
if (NULL == (newjob = (pcrs_job *)malloc(sizeof(pcrs_job))))
}
+#ifdef PCRE_STUDY_JIT_COMPILE
+ if (!(flags & PCRS_DYNAMIC))
+ {
+ pcre_study_options = PCRE_STUDY_JIT_COMPILE;
+ }
+#endif
+
/*
* Generate hints. This has little overhead, since the
* hints will be NULL for a boring pattern anyway.
*/
- newjob->hints = pcre_study(newjob->pattern, 0, &error);
+ newjob->hints = pcre_study(newjob->pattern, pcre_study_options, &error);
if (error != NULL)
{
*errptr = PCRS_ERR_STUDY;
pcrs_free_job(newjob);
return NULL;
}
-
- /*
- * Determine the number of capturing subpatterns.
+
+ /*
+ * 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
pcrs_free_job(newjob);
return NULL;
}
-
+
return newjob;
}
* the joblist to the subject.
* The subject itself is left untouched, memory for the result
* is malloc()ed and it is the caller's responsibility to free
- * the result when it's no longer needed.
+ * the result when it's no longer needed.
*
* Note: For convenient string handling, a null byte is
* appended to the result. It does not count towards the
* Parameters :
* 1 : joblist = the chained list of pcrs_jobs to be executed
* 2 : subject = the subject string
- * 3 : subject_length = the subject's length
- * 4 : result = char** for returning the result
+ * 3 : subject_length = the subject's length
+ * 4 : result = char** for returning the result
* 5 : result_length = size_t* for returning the result's length
*
* Returns : On success, the number of substitutions that were made.
pcrs_job *job;
char *old, *new = NULL;
int hits, total_hits;
-
+
old = subject;
*result_length = subject_length;
- hits = total_hits = 0;
+ total_hits = 0;
for (job = joblist; job != NULL; job = job->next)
{
* Parameters :
* 1 : job = the pcrs_job to be executed
* 2 : subject = the subject (== original) string
- * 3 : subject_length = the subject's length
- * 4 : result = char** for returning the result
+ * 3 : subject_length = the subject's length
+ * 4 : result = char** for returning the result (NULL on error)
* 5 : result_length = size_t* for returning the result's length
*
* Returns : On success, the number of substitutions that were made.
* failure, which may be translated to text using pcrs_strerror().
*
*********************************************************************/
-int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **result, size_t *result_length)
+int pcrs_execute(pcrs_job *job, const char *subject, size_t subject_length, char **result, size_t *result_length)
{
int offsets[3 * PCRS_MAX_SUBMATCHES],
offset,
pcrs_match *matches, *dummy;
char *result_offset;
- offset = i = k = 0;
+ offset = i = 0;
+ *result = NULL;
- /*
+ /*
* Sanity check & memory allocation
*/
if (job == NULL || job->pattern == NULL || job->substitute == NULL || NULL == subject)
{
- *result = NULL;
return(PCRS_ERR_BADJOB);
}
if (NULL == (matches = (pcrs_match *)malloc((size_t)max_matches * sizeof(pcrs_match))))
{
- *result = NULL;
return(PCRS_ERR_NOMEM);
}
memset(matches, '\0', (size_t)max_matches * sizeof(pcrs_match));
matches[i].submatch_offset[k] = offsets[2 * k];
/* Note: Non-found optional submatches have length -1-(-1)==0 */
- matches[i].submatch_length[k] = (size_t)(offsets[2 * k + 1] - offsets[2 * k]);
+ matches[i].submatch_length[k] = (size_t)(offsets[2 * k + 1] - offsets[2 * k]);
/* reserve mem for each submatch as often as it is ref'd */
newsize += matches[i].submatch_length[k] * (size_t)job->substitute->backref_count[k];
}
/* plus replacement text size minus match text size */
- newsize += strlen(job->substitute->text) - matches[i].submatch_length[0];
+ newsize += job->substitute->length - matches[i].submatch_length[0];
/* chunk before match */
matches[i].submatch_offset[PCRS_MAX_SUBMATCHES] = 0;
if (NULL == (dummy = (pcrs_match *)realloc(matches, (size_t)max_matches * sizeof(pcrs_match))))
{
free(matches);
- *result = NULL;
return(PCRS_ERR_NOMEM);
}
matches = dummy;
else
offset = offsets[1];
}
- /* Pass pcre error through if (bad) failiure */
+ /* Pass pcre error through if (bad) failure */
if (submatches < PCRE_ERROR_NOMATCH)
{
free(matches);
- return submatches;
+ return submatches;
}
matches_found = i;
- /*
+ /*
* Get memory for the result (must be freed by caller!)
* and append terminating null byte.
*/
}
- /*
+ /*
* Replace
*/
offset = 0;
for (i = 0; i < matches_found; i++)
{
/* copy the chunk preceding the match */
- memcpy(result_offset, subject + offset, (size_t)(matches[i].submatch_offset[0] - offset));
+ memcpy(result_offset, subject + offset, (size_t)(matches[i].submatch_offset[0] - offset));
result_offset += matches[i].submatch_offset[0] - offset;
/* For every segment of the substitute.. */
}
+#define is_hex_digit(x) ((x) && strchr("0123456789ABCDEF", toupper(x)))
+
+/*********************************************************************
+ *
+ * Function : is_hex_sequence
+ *
+ * Description : Checks the first four characters of a string
+ * and decides if they are a valid hex sequence
+ * (like '\x40').
+ *
+ * Parameters :
+ * 1 : sequence = The string to check
+ *
+ * Returns : Non-zero if it's valid sequence, or
+ * Zero if it isn't.
+ *
+ *********************************************************************/
+static int is_hex_sequence(const char *sequence)
+{
+ return (sequence[0] == '\\' &&
+ sequence[1] == 'x' &&
+ is_hex_digit(sequence[2]) &&
+ is_hex_digit(sequence[3]));
+}
+
+
+/*
+ * Functions below this line are only part of the pcrs version
+ * included in Privoxy. If you use any of them you should not
+ * try to dynamically link against external pcrs versions.
+ */
+
+/*********************************************************************
+ *
+ * Function : pcrs_job_is_dynamic
+ *
+ * Description : Checks if a job has the "D" (dynamic) option set.
+ *
+ * Parameters :
+ * 1 : job = The job to check
+ *
+ * Returns : TRUE if the job is indeed dynamic, otherwise
+ * FALSE
+ *
+ *********************************************************************/
+int pcrs_job_is_dynamic(char *job)
+{
+ const char delimiter = job[1];
+ const size_t length = strlen(job);
+ char *option;
+
+ if (length < 5)
+ {
+ /*
+ * The shortest valid (but useless)
+ * dynamic pattern is "s@@@D"
+ */
+ return FALSE;
+ }
+
+ /*
+ * Everything between the last character
+ * and the last delimiter is an option ...
+ */
+ for (option = job + length; *option != delimiter; option--)
+ {
+ if (*option == 'D')
+ {
+ /*
+ * ... and if said option is 'D' the job is dynamic.
+ */
+ return TRUE;
+ }
+ }
+ return FALSE;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : pcrs_get_delimiter
+ *
+ * Description : Tries to find a character that is safe to
+ * be used as a pcrs delimiter for a certain string.
+ *
+ * Parameters :
+ * 1 : string = The string to search in
+ *
+ * Returns : A safe delimiter if one was found, otherwise '\0'.
+ *
+ *********************************************************************/
+char pcrs_get_delimiter(const char *string)
+{
+ /*
+ * Some characters that are unlikely to
+ * be part of pcrs replacement strings.
+ */
+ static const char delimiters[] = "><#+*~%^-:;!@";
+ const char *d = delimiters;
+
+ /* Take the first delimiter that isn't part of the string */
+ while (*d && NULL != strchr(string, *d))
+ {
+ d++;
+ }
+ return *d;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : pcrs_execute_single_command
+ *
+ * Description : Apply single pcrs command to the subject.
+ * The subject itself is left untouched, memory for the result
+ * is malloc()ed and it is the caller's responsibility to free
+ * the result when it's no longer needed.
+ *
+ * Parameters :
+ * 1 : subject = the subject (== original) string
+ * 2 : pcrs_command = the pcrs command as string (s@foo@bar@)
+ * 3 : hits = int* for returning the number of modifications
+ *
+ * Returns : NULL in case of errors, otherwise the
+ * result of the pcrs command.
+ *
+ *********************************************************************/
+char *pcrs_execute_single_command(const char *subject, const char *pcrs_command, int *hits)
+{
+ size_t size;
+ char *result = NULL;
+ pcrs_job *job;
+
+ assert(subject);
+ assert(pcrs_command);
+
+ *hits = 0;
+ size = strlen(subject);
+
+ job = pcrs_compile_command(pcrs_command, hits);
+ if (NULL != job)
+ {
+ *hits = pcrs_execute(job, subject, size, &result, &size);
+ if (*hits < 0)
+ {
+ freez(result);
+ }
+ pcrs_free_job(job);
+ }
+ return result;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : pcrs_compile_dynamic_command
+ *
+ * Description : Takes a dynamic pcrs command, fills in the
+ * values of the variables and compiles it.
+ *
+ * Parameters :
+ * 1 : pcrs_command = The dynamic pcrs command to compile
+ * 2 : v = NULL terminated array of variables and their values.
+ * 3 : error = pcrs error code
+ *
+ * Returns : NULL in case of hard errors, otherwise the
+ * compiled pcrs job.
+ *
+ *********************************************************************/
+pcrs_job *pcrs_compile_dynamic_command(char *pcrs_command, const struct pcrs_variable v[], int *error)
+{
+ char buf[PCRS_BUFFER_SIZE];
+ const char *original_pcrs_command = pcrs_command;
+ char *pcrs_command_tmp = NULL;
+ pcrs_job *job = NULL;
+ int truncation = 0;
+ char d;
+ int ret;
+
+ while ((NULL != v->name) && (NULL != pcrs_command))
+ {
+ assert(NULL != v->value);
+
+ if (NULL == strstr(pcrs_command, v->name))
+ {
+ /*
+ * Skip the substitution if the variable
+ * name isn't part of the pattern.
+ */
+ v++;
+ continue;
+ }
+
+ /* Use pcrs to replace the variable with its value. */
+ d = pcrs_get_delimiter(v->value);
+ if ('\0' == d)
+ {
+ /* No proper delimiter found */
+ *error = PCRS_ERR_CMDSYNTAX;
+ freez(pcrs_command_tmp);
+ return NULL;
+ }
+
+ /*
+ * Variable names are supposed to contain alpha
+ * numerical characters plus '_' only.
+ */
+ assert(NULL == strchr(v->name, d));
+
+ ret = snprintf(buf, sizeof(buf), "s%c\\$%s%c%s%cDgT", d, v->name, d, v->value, d);
+ assert(ret >= 0);
+ if (ret >= sizeof(buf))
+ {
+ /*
+ * Value didn't completely fit into buffer,
+ * overwrite the end of the substitution text
+ * with a truncation message and close the pattern
+ * properly.
+ */
+ static const char warning[] = "... [too long, truncated]";
+ const size_t trailer_size = sizeof(warning) + 4; /* 4 for d + "DgT" */
+ char *trailer_start = buf + sizeof(buf) - trailer_size;
+
+ ret = snprintf(trailer_start, trailer_size, "%s%cDgT", warning, d);
+ assert(ret == trailer_size - 1);
+ assert(sizeof(buf) == strlen(buf) + 1);
+ truncation = 1;
+ }
+
+ pcrs_command_tmp = pcrs_execute_single_command(pcrs_command, buf, error);
+ if (NULL == pcrs_command_tmp)
+ {
+ return NULL;
+ }
+
+ if (pcrs_command != original_pcrs_command)
+ {
+ freez(pcrs_command);
+ }
+ pcrs_command = pcrs_command_tmp;
+
+ v++;
+ }
+
+ job = pcrs_compile_command(pcrs_command, error);
+ if (pcrs_command != original_pcrs_command)
+ {
+ freez(pcrs_command);
+ }
+
+ if (truncation)
+ {
+ *error = PCRS_WARN_TRUNCATION;
+ }
+
+ return job;
+
+}
+
+
/*
Local Variables:
tab-width: 3
projects / privoxy.git / blobdiff