X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=pcrs.c;h=6da82255508c4d9a4b46f660e151712b673ed9d3;hp=aecf206456b7edc53fc920a28fc8be16dfa56227;hb=e8baaf115bce6043896ba5ce07f90ab1f4c56617;hpb=e1fcf9e251441c56e4a81962a268feee59568dfa diff --git a/pcrs.c b/pcrs.c index aecf2064..6da82255 100644 --- a/pcrs.c +++ b/pcrs.c @@ -1,24 +1,21 @@ -const char pcrs_rcs[] = "$Id: pcrs.c,v 1.11 2001/08/15 15:32:03 oes Exp $"; - /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $ * - * Purpose : pcrs is a supplement to the brilliant pcre library by Philip - * Hazel and adds Perl-style substitution. That - * is, it mimics Perl's 's' operator. - * - * Currently, there's no documentation besides comments and the - * source itself :-( + * Purpose : pcrs is a supplement to the pcre library by Philip Hazel + * and adds Perl-style substitution. That + * is, it mimics Perl's 's' operator. See pcrs(3) for details. * - * Note: In addition to perl's options, 'U' for ungreedy and 'T' - * for trivial (i.e.: ignore backrefs in the substitute) are - * supported. + * 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additional functions and bug + * fixes that aren't part of the latest official pcrs package + * (which apparently is no longer maintained).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 * * - * This program is free software; you can redistribute it + * Copyright (C) 2006, 2007 Fabian Keil + * + * 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 @@ -36,84 +33,41 @@ const char pcrs_rcs[] = "$Id: pcrs.c,v 1.11 2001/08/15 15:32:03 oes Exp $"; * or write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * - * Revisions : - * $Log: pcrs.c,v $ - * Revision 1.11 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 - * - * *********************************************************************/ - -#include + #include +#include +#include + +/* + * 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" -#include -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 * @@ -122,7 +76,9 @@ const char pcrs_h_rcs[] = PCRS_H_VERSION; *********************************************************************/ const char *pcrs_strerror(const int error) { - if (error < 0) + static char buf[100]; + + if (error != 0) { switch (error) { @@ -136,21 +92,39 @@ const char *pcrs_strerror(const int 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 + /* + * 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"; - - /* What's that? */ - default: return "Unknown error"; + 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 */ + /* error >= 0: No error */ return "(pcrs:) Everything's just fine. Thanks for asking."; } @@ -167,15 +141,15 @@ const char *pcrs_strerror(const int 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 * *********************************************************************/ -int pcrs_parse_perl_options(const char *optstring, int *flags) +static int pcrs_parse_perl_options(const char *optstring, int *flags) { size_t i; int rc = 0; @@ -183,7 +157,7 @@ int pcrs_parse_perl_options(const char *optstring, int *flags) if (NULL == optstring) return 0; - for (i=0; i < strlen(optstring); i++) + for (i = 0; i < strlen(optstring); i++) { switch(optstring[i]) { @@ -195,7 +169,7 @@ int pcrs_parse_perl_options(const char *optstring, int *flags) case 's': rc |= PCRE_DOTALL; break; case 'x': rc |= PCRE_EXTENDED; break; case 'U': rc |= PCRE_UNGREEDY; break; - case 'T': *flags |= PCRS_TRIVIAL; break; + case 'T': *flags |= PCRS_TRIVIAL; break; default: break; } } @@ -204,6 +178,38 @@ int pcrs_parse_perl_options(const char *optstring, int *flags) } +#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 @@ -228,12 +234,16 @@ int pcrs_parse_perl_options(const char *optstring, int *flags) * the reason. * *********************************************************************/ -pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr) +static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr) { - int length, i, k, l, quoted; + 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; /* @@ -262,8 +272,8 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl *errptr = PCRS_ERR_NOMEM; return NULL; } - memset(r, '\0', length + 1); - + memset(text, '\0', length + 1); + /* * In trivial mode, just copy the substitute text @@ -271,7 +281,7 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl if (trivialflag) { text = strncpy(text, replacement, length + 1); - k = length; + k = (int)length; } /* @@ -279,7 +289,7 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl */ else { - while(i < length) + while (i < (int)length) { /* Quoting */ if (replacement[i] == '\\') @@ -293,7 +303,7 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl { if (replacement[i+1] && strchr("tnrfae0", replacement[i+1])) { - switch(replacement[++i]) + switch (replacement[++i]) { case 't': text[k++] = '\t'; @@ -308,7 +318,7 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl text[k++] = '\f'; break; case 'a': - text[k++] = '\a'; + text[k++] = 7; break; case 'e': text[k++] = 27; @@ -319,6 +329,20 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl } 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; @@ -329,28 +353,38 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl } /* Backreferences */ - if (replacement[i] == '$' && !quoted && i < length - 1) + if (replacement[i] == '$' && !quoted && i < (int)(length - 1)) { char *symbol, symbols[] = "'`+&"; - r->block_length[l] = k - r->block_offset[l]; + 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(replacement[i + 1])) + if (isdigit((int)replacement[i + 1])) { - while (i < length && isdigit(replacement[++i])) + 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; @@ -361,7 +395,7 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl } else /* $' or $` */ { - r->backref[l] = PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols); + r->backref[l] = (int)(PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols)); } i += 2; } @@ -372,19 +406,25 @@ pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialfl 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++]; @@ -397,7 +437,8 @@ plainchar: */ r->text = text; r->backrefs = l; - r->block_length[l] = k - r->block_offset[l]; + r->length = (size_t)k; + r->block_length[l] = (size_t)(k - r->block_offset[l]); return r; @@ -409,13 +450,13 @@ plainchar: * 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) @@ -459,7 +500,7 @@ pcrs_job *pcrs_free_job(pcrs_job *job) *********************************************************************/ void pcrs_free_joblist(pcrs_job *joblist) { - while ( NULL != (joblist = pcrs_free_job(joblist)) ) {}; + while (NULL != (joblist = pcrs_free_job(joblist))) {}; return; @@ -470,7 +511,7 @@ void pcrs_free_joblist(pcrs_job *joblist) * * 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. @@ -487,13 +528,14 @@ void pcrs_free_joblist(pcrs_job *joblist) *********************************************************************/ pcrs_job *pcrs_compile_command(const char *command, int *errptr) { - int i, k, l, limit, quoted = FALSE; + 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 */ @@ -510,9 +552,9 @@ pcrs_job *pcrs_compile_command(const char *command, int *errptr) tokens[l] = (char *) malloc(limit + 1); - for (i=0; i <= limit; i++) + for (i = 0; i <= (int)limit; i++) { - + if (command[i] == delimiter && !quoted) { if (l == 3) @@ -524,7 +566,7 @@ pcrs_job *pcrs_compile_command(const char *command, int *errptr) tokens[++l] = tokens[0] + k; continue; } - + else if (command[i] == '\\' && !quoted) { quoted = TRUE; @@ -546,11 +588,11 @@ pcrs_job *pcrs_compile_command(const char *command, int *errptr) free(tokens[0]); return NULL; } - + newjob = pcrs_compile(tokens[1], tokens[2], tokens[3], errptr); free(tokens[0]); return newjob; - + } @@ -582,14 +624,14 @@ pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char * *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)))) @@ -629,10 +671,10 @@ pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char * 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))) @@ -640,7 +682,7 @@ pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char * pcrs_free_job(newjob); return NULL; } - + /* * Compile the substitute @@ -650,7 +692,7 @@ pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char * pcrs_free_job(newjob); return NULL; } - + return newjob; } @@ -667,37 +709,42 @@ pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char * * 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 - * INCLUDING the terminating zero, if string! - * 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. * May be > 1 if job->flags contained PCRS_GLOBAL - * On failiure, the (negative) pcre error code describing the - * failiure, which may be translated to text using pcrs_strerror(). + * 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; + char *old, *new = NULL; int hits, total_hits; - + old = subject; *result_length = subject_length; - hits = 0; + 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) { - *result = NULL; return(hits); } else @@ -708,7 +755,8 @@ int pcrs_execute_list(pcrs_job *joblist, char *subject, size_t subject_length, c } *result = new; - return(hits); + return(total_hits); + } @@ -722,92 +770,94 @@ int pcrs_execute_list(pcrs_job *joblist, char *subject, size_t subject_length, c * 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 - * INCLUDING the terminating zero, if string! - * 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. * May be > 1 if job->flags contained PCRS_GLOBAL - * On failiure, the (negative) pcre error code describing the - * failiure, which may be translated to text using pcrs_strerror(). + * 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, 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, i, k, + offset, + i, k, matches_found, - newsize, submatches, max_matches = PCRS_MAX_MATCH_INIT; + size_t newsize; 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) + if (job == NULL || job->pattern == NULL || job->substitute == NULL || NULL == subject) { - *result = NULL; return(PCRS_ERR_BADJOB); } - if (NULL == (matches = (pcrs_match *)malloc(max_matches * sizeof(pcrs_match)))) + if (NULL == (matches = (pcrs_match *)malloc((size_t)max_matches * sizeof(pcrs_match)))) { - *result = NULL; return(PCRS_ERR_NOMEM); } - memset(matches, '\0', max_matches * sizeof(pcrs_match)); + memset(matches, '\0', (size_t)max_matches * sizeof(pcrs_match)); /* * Find the pattern and calculate the space * requirements for the result */ - newsize=subject_length; + newsize = subject_length; - while ((submatches = pcre_exec(job->pattern, job->hints, subject, subject_length, offset, 0, offsets, 3 * PCRS_MAX_SUBMATCHES)) > 0) + 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++) + 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] = 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] * job->substitute->backref_count[k]; + 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; - matches[i].submatch_length[PCRS_MAX_SUBMATCHES] = offsets[0]; - newsize += offsets[0] * job->substitute->backref_count[PCRS_MAX_SUBMATCHES]; + 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 - offsets[1] - 1; - newsize += (subject_length - offsets[1]) * job->substitute->backref_count[PCRS_MAX_SUBMATCHES + 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 *= PCRS_MAX_MATCH_GROW; - if (NULL == (dummy = (pcrs_match *)realloc(matches, max_matches * sizeof(pcrs_match)))) + 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); - *result = NULL; return(PCRS_ERR_NOMEM); } matches = dummy; @@ -818,7 +868,7 @@ int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **res /* Don't loop on empty matches */ if (offsets[1] == offset) - if (offset < subject_length) + if ((size_t)offset < subject_length) offset++; else break; @@ -826,39 +876,44 @@ int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **res 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 + /* + * Get memory for the result (must be freed by caller!) + * and append terminating null byte. */ - if ((*result = (char *)malloc(newsize)) == NULL) /* must be free()d by caller */ + 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++) + for (i = 0; i < matches_found; i++) { /* copy the chunk preceding the match */ - memcpy(result_offset, subject + offset, 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.. */ - for (k=0; k <= job->substitute->backrefs; k++) + 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]); @@ -868,7 +923,9 @@ int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **res if (k != job->substitute->backrefs /* ..in legal range.. */ && job->substitute->backref[k] < PCRS_MAX_SUBMATCHES + 2 - /* ..and referencing a nonempty match.. */ + /* ..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. */ @@ -880,11 +937,11 @@ int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **res result_offset += matches[i].submatch_length[job->substitute->backref[k]]; } } - offset = matches[i].submatch_offset[0] + matches[i].submatch_length[0]; + offset = matches[i].submatch_offset[0] + (int)matches[i].submatch_length[0]; } /* Copy the rest. */ - memcpy(result_offset, subject + offset, subject_length - offset); + memcpy(result_offset, subject + offset, subject_length - (size_t)offset); *result_length = newsize; free(matches); @@ -893,6 +950,269 @@ int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **res } +#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; + +} + + +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 : 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%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