-const char pcrs_rcs[] = "$Id: pcrs.c,v 1.22 2006/12/24 17:34:20 fabiankeil Exp $";
-
+const char pcrs_rcs[] = "$Id: pcrs.c,v 1.32 2009/05/19 17:44:22 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+ * (which apparently is no longer maintained).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>
*
+ * 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 Lesser
* General Public License (LGPL), version 2.1, which should
* 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"
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);
/*********************************************************************
*
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
}
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;
*/
r->text = text;
r->backrefs = l;
+ r->length = (size_t)k;
r->block_length[l] = (size_t)(k - r->block_offset[l]);
return r;
char *tokens[4];
pcrs_job *newjob;
- i = k = l = 0;
+ k = l = 0;
/*
* Tokenize the perl command
old = subject;
*result_length = subject_length;
- hits = total_hits = 0;
+ total_hits = 0;
for (job = joblist; job != NULL; job = job->next)
{
* 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;
/*
* Sanity check & memory allocation
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;
}
+#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.
+ */
+ char delimiters[] = "><§#+*~%^°-:;µ!@";
+ 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;
+
+}
+
+
+static const char warning[] = "... [too long, truncated]";
+/*********************************************************************
+ *
+ * Function : pcrs_compile_dynamic_command
+ *
+ * Description : Takes a dynamic pcrs command, fills in the
+ * values of the variables and compiles it.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : pcrs_command = The dynamic pcrs command to compile
+ * 3 : v = NULL terminated array of variables and their values.
+ * 4 : 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;
+ 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%cgT", 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.
+ */
+ const size_t trailer_size = sizeof(warning) + 3; /* 3 for d + "gT" */
+ char *trailer_start = buf + sizeof(buf) - trailer_size;
+
+ ret = snprintf(trailer_start, trailer_size, "%s%cgT", 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