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- /*********************************************************************
- *
- * File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $
- *
- * Purpose : pcrs is a supplement to the pcre library by Philip Hazel
- * <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- * (which apparently is no longer maintained).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 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 GNU General Public
- * License for more details.
- *
- * 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.
- *
- *********************************************************************/
- #include <string.h>
- #include <ctype.h>
- #include <assert.h>
- /*
- * Include project.h just so that the right pcre.h gets
- * included from there
- */
- #include "project.h"
- /* For snprintf only */
- #include "miscutil.h"
- /* For xtoi */
- #include "encode.h"
- #include "pcrs.h"
- /*
- * 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
- *
- * Returns : char * to the descriptive string
- *
- *********************************************************************/
- const char *pcrs_strerror(const int error)
- {
- static char buf[100];
- if (error != 0)
- {
- switch (error)
- {
- /* Passed-through PCRE error: */
- case PCRE_ERROR_NOMEMORY: return "(pcre:) No memory";
- /* Shouldn't happen unless PCRE or PCRS bug, or user messed with compiled job: */
- case PCRE_ERROR_NULL: return "(pcre:) NULL code or subject or ovector";
- case PCRE_ERROR_BADOPTION: return "(pcre:) Unrecognized option bit";
- case PCRE_ERROR_BADMAGIC: return "(pcre:) Bad magic number in code";
- 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_NOMATCH: return "(pcre:) Water in power supply";
- #ifdef PCRE_ERROR_MATCHLIMIT
- /*
- * Only reported by PCRE versions newer than our own.
- */
- case PCRE_ERROR_MATCHLIMIT: return "(pcre:) Match limit reached";
- #endif /* def PCRE_ERROR_MATCHLIMIT */
- /* PCRS errors: */
- case PCRS_ERR_NOMEM: return "(pcrs:) No memory";
- case PCRS_ERR_CMDSYNTAX: return "(pcrs:) Syntax error while parsing command";
- 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:
- snprintf(buf, sizeof(buf),
- "Error code %d. For details, check the pcre documentation.",
- error);
- return buf;
- }
- }
- /* error >= 0: No error */
- return "(pcrs:) Everything's just fine. Thanks for asking.";
- }
- /*********************************************************************
- *
- * 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
- * pcre equivalent of the symbolic optstring.
- * Since pcre doesn't know about Perl's 'g' (global) or pcrs',
- * '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
- *
- *********************************************************************/
- static int pcrs_parse_perl_options(const char *optstring, int *flags)
- {
- size_t i;
- int rc = 0;
- *flags = 0;
- if (NULL == optstring) return 0;
- for (i = 0; i < strlen(optstring); i++)
- {
- switch(optstring[i])
- {
- case 'e': break; /* ToDo ;-) */
- case 'g': *flags |= PCRS_GLOBAL; break;
- case 'i': rc |= PCRE_CASELESS; break;
- case 'm': rc |= PCRE_MULTILINE; break;
- 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;
- }
- }
- return rc;
- }
- #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
- *
- * Description : This function takes a Perl-style replacement (2nd argument
- * to the s/// operator and returns a compiled pcrs_substitute,
- * or NULL if memory allocation for the substitute structure
- * fails.
- *
- * Parameters :
- * 1 : replacement = replacement part of s/// operator
- * in perl syntax
- * 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
- * error is encountered. In that case, *errptr has
- * the reason.
- *
- *********************************************************************/
- static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr)
- {
- int i, k, l, quoted;
- char *text;
- pcrs_substitute *r;
- #ifndef FUZZ
- size_t length;
- #else
- static size_t length;
- #endif
- i = k = l = quoted = 0;
- /*
- * Sanity check
- */
- if (NULL == replacement)
- {
- replacement = "";
- }
- /*
- * Get memory or fail
- */
- if (NULL == (r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute))))
- {
- *errptr = PCRS_ERR_NOMEM;
- 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(text, '\0', length + 1);
- /*
- * In trivial mode, just copy the substitute text
- */
- if (trivialflag)
- {
- text = strncpy(text, replacement, length + 1);
- k = (int)length;
- }
- /*
- * Else, parse, cut out and record all backreferences
- */
- else
- {
- while (i < (int)length)
- {
- /* Quoting */
- if (replacement[i] == '\\')
- {
- if (quoted)
- {
- text[k++] = replacement[i++];
- quoted = 0;
- }
- else
- {
- if (replacement[i+1] && strchr("tnrfae0", replacement[i+1]))
- {
- switch (replacement[++i])
- {
- case 't':
- text[k++] = '\t';
- break;
- case 'n':
- text[k++] = '\n';
- break;
- case 'r':
- text[k++] = '\r';
- break;
- case 'f':
- text[k++] = '\f';
- break;
- case 'a':
- text[k++] = 7;
- break;
- case 'e':
- text[k++] = 27;
- break;
- case '0':
- text[k++] = '\0';
- break;
- }
- 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;
- i++;
- }
- }
- continue;
- }
- /* Backreferences */
- 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 (isdigit((int)replacement[i + 1]))
- {
- while (i < (int)length && isdigit((int)replacement[++i]))
- {
- r->backref[l] = r->backref[l] * 10 + replacement[i] - 48;
- }
- 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 if (symbol - symbols == 3) /* $& */
- {
- r->backref[l] = 0;
- }
- else /* $' or $` */
- {
- r->backref[l] = (int)(PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols));
- }
- i += 2;
- }
- /* Invalid backref -> plain '$' */
- else
- {
- goto plainchar;
- }
- assert(r->backref[l] < PCRS_MAX_SUBMATCHES + 2);
- /* Valid and in range? -> record */
- 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++];
- quoted = 0;
- }
- } /* -END- if (!trivialflag) */
- /*
- * Finish & return
- */
- 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
- * 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.
- *
- *********************************************************************/
- pcrs_job *pcrs_free_job(pcrs_job *job)
- {
- pcrs_job *next;
- if (job == NULL)
- {
- return NULL;
- }
- else
- {
- next = job->next;
- if (job->pattern != NULL) free(job->pattern);
- 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);
- free(job->substitute);
- }
- free(job);
- }
- return next;
- }
- /*********************************************************************
- *
- * Function : pcrs_free_joblist
- *
- * Description : Iterates through a chained list of pcrs_job's and
- * frees them using pcrs_free_job.
- *
- * Parameters :
- * 1 : joblist = pointer to the first pcrs_job structure to
- * be freed
- *
- * Returns : N/A
- *
- *********************************************************************/
- void pcrs_free_joblist(pcrs_job *joblist)
- {
- while (NULL != (joblist = pcrs_free_job(joblist))) {};
- return;
- }
- /*********************************************************************
- *
- * Function : pcrs_compile_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.
- *
- * Parameters :
- * 1 : command = string with perl-style s/// command
- * 2 : errptr = pointer to an integer in which error
- * conditions can be returned.
- *
- * Returns : a corresponding pcrs_job data structure, or NULL
- * if an error was encountered. In that case, *errptr
- * has the reason.
- *
- *********************************************************************/
- pcrs_job *pcrs_compile_command(const char *command, int *errptr)
- {
- int i, k, l, quoted = FALSE;
- size_t limit;
- char delimiter;
- char *tokens[4];
- pcrs_job *newjob;
- k = l = 0;
- /*
- * Tokenize the perl command
- */
- limit = strlen(command);
- if (limit < 4)
- {
- *errptr = PCRS_ERR_CMDSYNTAX;
- return NULL;
- }
- else
- {
- delimiter = command[1];
- }
- tokens[l] = (char *) malloc(limit + 1);
- for (i = 0; i <= (int)limit; i++)
- {
- if (command[i] == delimiter && !quoted)
- {
- if (l == 3)
- {
- l = -1;
- break;
- }
- tokens[0][k++] = '\0';
- tokens[++l] = tokens[0] + k;
- continue;
- }
- else if (command[i] == '\\' && !quoted)
- {
- quoted = TRUE;
- if (command[i+1] == delimiter) continue;
- }
- else
- {
- quoted = FALSE;
- }
- tokens[0][k++] = command[i];
- }
- /*
- * Syntax error ?
- */
- if (l != 3)
- {
- *errptr = PCRS_ERR_CMDSYNTAX;
- free(tokens[0]);
- return NULL;
- }
- newjob = pcrs_compile(tokens[1], tokens[2], tokens[3], errptr);
- free(tokens[0]);
- return newjob;
- }
- /*********************************************************************
- *
- * Function : pcrs_compile
- *
- * Description : Takes the three arguments to a perl s/// command
- * and compiles a pcrs_job structure from them.
- *
- * Parameters :
- * 1 : pattern = string with perl-style pattern
- * 2 : substitute = string with perl-style substitute
- * 3 : options = string with perl-style options
- * 4 : errptr = pointer to an integer in which error
- * conditions can be returned.
- *
- * Returns : a corresponding pcrs_job data structure, or NULL
- * if an error was encountered. In that case, *errptr
- * has the reason.
- *
- *********************************************************************/
- pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char *options, int *errptr)
- {
- pcrs_job *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))))
- {
- *errptr = PCRS_ERR_NOMEM;
- return NULL;
- }
- memset(newjob, '\0', sizeof(pcrs_job));
- /*
- * Evaluate the options
- */
- newjob->options = pcrs_parse_perl_options(options, &flags);
- newjob->flags = flags;
- /*
- * Compile the pattern
- */
- newjob->pattern = pcre_compile(pattern, newjob->options, &error, errptr, NULL);
- if (newjob->pattern == NULL)
- {
- pcrs_free_job(newjob);
- return NULL;
- }
- #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, pcre_study_options, &error);
- if (error != NULL)
- {
- *errptr = PCRS_ERR_STUDY;
- pcrs_free_job(newjob);
- return NULL;
- }
- /*
- * 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, capturecount, errptr)))
- {
- pcrs_free_job(newjob);
- return NULL;
- }
- return newjob;
- }
- /*********************************************************************
- *
- * Function : pcrs_execute_list
- *
- * Description : This is a multiple job wrapper for pcrs_execute().
- * Apply the regular substitutions defined by the jobs in
- * 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.
- *
- * Note: For convenient string handling, a null byte is
- * appended to the result. It does not count towards the
- * result_length, though.
- *
- *
- * 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
- * 5 : result_length = size_t* for returning the result's length
- *
- * Returns : On success, the number of substitutions that were made.
- * May be > 1 if job->flags contained PCRS_GLOBAL
- * On failure, the (negative) pcre error code describing the
- * failure, which may be translated to text using pcrs_strerror().
- *
- *********************************************************************/
- int pcrs_execute_list(pcrs_job *joblist, char *subject, size_t subject_length, char **result, size_t *result_length)
- {
- pcrs_job *job;
- char *old, *new = NULL;
- int hits, total_hits;
- old = subject;
- *result_length = subject_length;
- total_hits = 0;
- for (job = joblist; job != NULL; job = job->next)
- {
- hits = pcrs_execute(job, old, *result_length, &new, result_length);
- if (old != subject) free(old);
- if (hits < 0)
- {
- return(hits);
- }
- else
- {
- total_hits += hits;
- old = new;
- }
- }
- *result = new;
- return(total_hits);
- }
- /*********************************************************************
- *
- * Function : pcrs_execute
- *
- * Description : Apply the regular substitution defined by the job 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.
- *
- * Note: For convenient string handling, a null byte is
- * appended to the result. It does not count towards the
- * result_length, though.
- *
- * 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 (NULL on error)
- * 5 : result_length = size_t* for returning the result's length
- *
- * Returns : On success, the number of substitutions that were made.
- * May be > 1 if job->flags contained PCRS_GLOBAL
- * On failure, the (negative) pcre error code describing the
- * failure, which may be translated to text using pcrs_strerror().
- *
- *********************************************************************/
- 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,
- i, k,
- matches_found,
- submatches,
- max_matches = PCRS_MAX_MATCH_INIT;
- size_t newsize;
- pcrs_match *matches, *dummy;
- char *result_offset;
- offset = i = 0;
- *result = NULL;
- /*
- * Sanity check & memory allocation
- */
- if (job == NULL || job->pattern == NULL || job->substitute == NULL || NULL == subject)
- {
- return(PCRS_ERR_BADJOB);
- }
- if (NULL == (matches = (pcrs_match *)malloc((size_t)max_matches * sizeof(pcrs_match))))
- {
- return(PCRS_ERR_NOMEM);
- }
- memset(matches, '\0', (size_t)max_matches * sizeof(pcrs_match));
- /*
- * Find the pattern and calculate the space
- * requirements for the result
- */
- newsize = subject_length;
- while ((submatches = pcre_exec(job->pattern, job->hints, subject, (int)subject_length, offset, 0, offsets, 3 * PCRS_MAX_SUBMATCHES)) > 0)
- {
- job->flags |= PCRS_SUCCESS;
- matches[i].submatches = submatches;
- for (k = 0; k < submatches; k++)
- {
- 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]);
- /* 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 += job->substitute->length - matches[i].submatch_length[0];
- /* chunk before match */
- matches[i].submatch_offset[PCRS_MAX_SUBMATCHES] = 0;
- matches[i].submatch_length[PCRS_MAX_SUBMATCHES] = (size_t)offsets[0];
- newsize += (size_t)offsets[0] * (size_t)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 - (size_t)offsets[1] - 1;
- newsize += (subject_length - (size_t)offsets[1]) * (size_t)job->substitute->backref_count[PCRS_MAX_SUBMATCHES + 1];
- /* Storage for matches exhausted? -> Extend! */
- if (++i >= max_matches)
- {
- max_matches = (int)(max_matches * PCRS_MAX_MATCH_GROW);
- if (NULL == (dummy = (pcrs_match *)realloc(matches, (size_t)max_matches * sizeof(pcrs_match))))
- {
- free(matches);
- return(PCRS_ERR_NOMEM);
- }
- matches = dummy;
- }
- /* Non-global search or limit reached? */
- if (!(job->flags & PCRS_GLOBAL)) break;
- /* Don't loop on empty matches */
- if (offsets[1] == offset)
- if ((size_t)offset < subject_length)
- offset++;
- else
- break;
- /* Go find the next one */
- else
- offset = offsets[1];
- }
- /* Pass pcre error through if (bad) failure */
- if (submatches < PCRE_ERROR_NOMATCH)
- {
- free(matches);
- return submatches;
- }
- matches_found = i;
- /*
- * Get memory for the result (must be freed by caller!)
- * and append terminating null byte.
- */
- if ((*result = (char *)malloc(newsize + 1)) == NULL)
- {
- free(matches);
- return PCRS_ERR_NOMEM;
- }
- else
- {
- (*result)[newsize] = '\0';
- }
- /*
- * Replace
- */
- offset = 0;
- result_offset = *result;
- 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));
- result_offset += matches[i].submatch_offset[0] - offset;
- /* For every segment of the substitute.. */
- for (k = 0; k <= job->substitute->backrefs; k++)
- {
- /* ...copy its text.. */
- memcpy(result_offset, job->substitute->text + job->substitute->block_offset[k], job->substitute->block_length[k]);
- result_offset += job->substitute->block_length[k];
- /* ..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 + 2
- /* ..and referencing a real submatch.. */
- && job->substitute->backref[k] < matches[i].submatches
- /* ..that is nonempty.. */
- && matches[i].submatch_length[job->substitute->backref[k]] > 0)
- {
- /* ..copy the submatch that is ref'd. */
- memcpy(
- result_offset,
- subject + matches[i].submatch_offset[job->substitute->backref[k]],
- matches[i].submatch_length[job->substitute->backref[k]]
- );
- result_offset += matches[i].submatch_length[job->substitute->backref[k]];
- }
- }
- offset = matches[i].submatch_offset[0] + (int)matches[i].submatch_length[0];
- }
- /* Copy the rest. */
- memcpy(result_offset, subject + offset, subject_length - (size_t)offset);
- *result_length = newsize;
- free(matches);
- return matches_found;
- }
- #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
- end:
- */
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