/* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla Communicator client code, released * March 31, 1998. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 1998-1999 * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Alternatively, the contents of this file may be used under the terms of * either of the GNU General Public License Version 2 or later (the "GPL"), * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ #include "ldap-int.h" #if defined( macintosh ) || defined( DOS ) || defined( _WINDOWS ) || defined( NEED_BSDREGEX ) || defined( XP_OS2) #include "regex.h" /* * regex - Regular expression pattern matching and replacement * * By: Ozan S. Yigit (oz) * Dept. of Computer Science * York University * * These routines are the PUBLIC DOMAIN equivalents of regex * routines as found in 4.nBSD UN*X, with minor extensions. * * These routines are derived from various implementations found * in software tools books, and Conroy's grep. They are NOT derived * from licensed/restricted software. * For more interesting/academic/complicated implementations, * see Henry Spencer's regexp routines, or GNU Emacs pattern * matching module. * * Use the actual CCL code in the CLO * section of pmatch. No need for a recursive * pmatch call. * * Use a bitmap table to set char bits in an * 8-bit chunk. * * Interfaces: * re_comp: compile a regular expression into a NFA. * * char *re_comp(s) * char *s; * * re_exec: execute the NFA to match a pattern. * * int re_exec(s) * char *s; * * re_modw change re_exec's understanding of what a "word" * looks like (for \< and \>) by adding into the * hidden word-syntax table. * * void re_modw(s) * char *s; * * re_subs: substitute the matched portions in a new string. * * int re_subs(src, dst) * char *src; * char *dst; * * re_fail: failure routine for re_exec. * * void re_fail(msg, op) * char *msg; * char op; * * Regular Expressions: * * [1] char matches itself, unless it is a special * character (metachar): . \ [ ] * + ^ $ * * [2] . matches any character. * * [3] \ matches the character following it, except * when followed by a left or right round bracket, * a digit 1 to 9 or a left or right angle bracket. * (see [7], [8] and [9]) * It is used as an escape character for all * other meta-characters, and itself. When used * in a set ([4]), it is treated as an ordinary * character. * * [4] [set] matches one of the characters in the set. * If the first character in the set is "^", * it matches a character NOT in the set, i.e. * complements the set. A shorthand S-E is * used to specify a set of characters S upto * E, inclusive. The special characters "]" and * "-" have no special meaning if they appear * as the first chars in the set. * examples: match: * * [a-z] any lowercase alpha * * [^]-] any char except ] and - * * [^A-Z] any char except uppercase * alpha * * [a-zA-Z] any alpha * * [5] * any regular expression form [1] to [4], followed by * closure char (*) matches zero or more matches of * that form. * * [6] + same as [5], except it matches one or more. * * [7] a regular expression in the form [1] to [10], enclosed * as \(form\) matches what form matches. The enclosure * creates a set of tags, used for [8] and for * pattern substution. The tagged forms are numbered * starting from 1. * * [8] a \ followed by a digit 1 to 9 matches whatever a * previously tagged regular expression ([7]) matched. * * [9] \< a regular expression starting with a \< construct * \> and/or ending with a \> construct, restricts the * pattern matching to the beginning of a word, and/or * the end of a word. A word is defined to be a character * string beginning and/or ending with the characters * A-Z a-z 0-9 and _. It must also be preceded and/or * followed by any character outside those mentioned. * * [10] a composite regular expression xy where x and y * are in the form [1] to [10] matches the longest * match of x followed by a match for y. * * [11] ^ a regular expression starting with a ^ character * $ and/or ending with a $ character, restricts the * pattern matching to the beginning of the line, * or the end of line. [anchors] Elsewhere in the * pattern, ^ and $ are treated as ordinary characters. * * * Acknowledgements: * * HCR's Hugh Redelmeier has been most helpful in various * stages of development. He convinced me to include BOW * and EOW constructs, originally invented by Rob Pike at * the University of Toronto. * * References: * Software tools Kernighan & Plauger * Software tools in Pascal Kernighan & Plauger * Grep [rsx-11 C dist] David Conroy * ed - text editor Un*x Programmer's Manual * Advanced editing on Un*x B. W. Kernighan * RegExp routines Henry Spencer * * Notes: * * This implementation uses a bit-set representation for character * classes for speed and compactness. Each character is represented * by one bit in a 128-bit block. Thus, CCL always takes a * constant 16 bytes in the internal nfa, and re_exec does a single * bit comparison to locate the character in the set. * * Examples: * * pattern: foo*.* * compile: CHR f CHR o CLO CHR o END CLO ANY END END * matches: fo foo fooo foobar fobar foxx ... * * pattern: fo[ob]a[rz] * compile: CHR f CHR o CCL bitset CHR a CCL bitset END * matches: fobar fooar fobaz fooaz * * pattern: foo\\+ * compile: CHR f CHR o CHR o CHR \ CLO CHR \ END END * matches: foo\ foo\\ foo\\\ ... * * pattern: \(foo\)[1-3]\1 (same as foo[1-3]foo) * compile: BOT 1 CHR f CHR o CHR o EOT 1 CCL bitset REF 1 END * matches: foo1foo foo2foo foo3foo * * pattern: \(fo.*\)-\1 * compile: BOT 1 CHR f CHR o CLO ANY END EOT 1 CHR - REF 1 END * matches: foo-foo fo-fo fob-fob foobar-foobar ... */ #define MAXNFA 1024 #define MAXTAG 10 #define OKP 1 #define NOP 0 #define CHR 1 #define ANY 2 #define CCL 3 #define BOL 4 #define EOL 5 #define BOT 6 #define EOT 7 #define BOW 8 #define EOW 9 #define REF 10 #define CLO 11 #define END 0 /* * The following defines are not meant to be changeable. * They are for readability only. */ #define MAXCHR 128 #define CHRBIT 8 #define BITBLK MAXCHR/CHRBIT #define BLKIND 0170 #define BITIND 07 #define ASCIIB 0177 /* Plain char, on the other hand, may be signed or unsigned; it depends on * the platform and perhaps a compiler option. A hard fact of life, in C. * * 6-April-1999 mcs@netscape.com: replaced CHAR with REGEXCHAR to avoid * conflicts with system types on Win32. Changed typedef * for REGEXCHAR to always be unsigned, which seems right. */ typedef unsigned char REGEXCHAR; static int tagstk[MAXTAG]; /* subpat tag stack..*/ static REGEXCHAR nfa[MAXNFA]; /* automaton.. */ static int sta = NOP; /* status of lastpat */ static REGEXCHAR bittab[BITBLK]; /* bit table for CCL */ /* pre-set bits... */ static REGEXCHAR bitarr[] = {1,2,4,8,16,32,64,128}; static void chset(REGEXCHAR c) { bittab[((c) & (unsigned)BLKIND) >> 3] |= bitarr[(c) & BITIND]; } #define badpat(x) (*nfa = END, x) #define store(x) *mp++ = x char * LDAP_CALL re_comp( const char *pat ) { register REGEXCHAR *p; /* pattern pointer */ register REGEXCHAR *mp=nfa; /* nfa pointer */ register REGEXCHAR *lp; /* saved pointer.. */ register REGEXCHAR *sp=nfa; /* another one.. */ register int tagi = 0; /* tag stack index */ register int tagc = 1; /* actual tag count */ register int n; register REGEXCHAR mask; /* xor mask -CCL/NCL */ int c1, c2; if (!pat || !*pat) { if (sta) { return 0; } else { return badpat("No previous regular expression"); } } sta = NOP; for (p = (REGEXCHAR*)pat; *p; p++) { lp = mp; switch(*p) { case '.': /* match any char.. */ store(ANY); break; case '^': /* match beginning.. */ if (p == (REGEXCHAR*)pat) store(BOL); else { store(CHR); store(*p); } break; case '$': /* match endofline.. */ if (!*(p+1)) store(EOL); else { store(CHR); store(*p); } break; case '[': /* match char class..*/ store(CCL); if (*++p == '^') { mask = 0377; p++; } else mask = 0; if (*p == '-') /* real dash */ chset(*p++); if (*p == ']') /* real brac */ chset(*p++); while (*p && *p != ']') { if (*p == '-' && *(p+1) && *(p+1) != ']') { p++; c1 = *(p-2) + 1; c2 = *p++; while (c1 <= c2) chset((REGEXCHAR)c1++); } #ifdef EXTEND else if (*p == '\\' && *(p+1)) { p++; chset(*p++); } #endif else chset(*p++); } if (!*p) return badpat("Missing ]"); for (n = 0; n < BITBLK; bittab[n++] = (REGEXCHAR) 0) store(mask ^ bittab[n]); break; case '*': /* match 0 or more.. */ case '+': /* match 1 or more.. */ if (p == (REGEXCHAR*)pat) return badpat("Empty closure"); lp = sp; /* previous opcode */ if (*lp == CLO) /* equivalence.. */ break; switch(*lp) { case BOL: case BOT: case EOT: case BOW: case EOW: case REF: return badpat("Illegal closure"); default: break; } if (*p == '+') for (sp = mp; lp < sp; lp++) store(*lp); store(END); store(END); sp = mp; while (--mp > lp) *mp = mp[-1]; store(CLO); mp = sp; break; case '\\': /* tags, backrefs .. */ switch(*++p) { case '(': if (tagc < MAXTAG) { tagstk[++tagi] = tagc; store(BOT); store(tagc++); } else return badpat("Too many \\(\\) pairs"); break; case ')': if (*sp == BOT) return badpat("Null pattern inside \\(\\)"); if (tagi > 0) { store(EOT); store(tagstk[tagi--]); } else return badpat("Unmatched \\)"); break; case '<': store(BOW); break; case '>': if (*sp == BOW) return badpat("Null pattern inside \\<\\>"); store(EOW); break; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': n = *p-'0'; if (tagi > 0 && tagstk[tagi] == n) return badpat("Cyclical reference"); if (tagc > n) { store(REF); store(n); } else return badpat("Undetermined reference"); break; #ifdef EXTEND case 'b': store(CHR); store('\b'); break; case 'n': store(CHR); store('\n'); break; case 'f': store(CHR); store('\f'); break; case 'r': store(CHR); store('\r'); break; case 't': store(CHR); store('\t'); break; #endif default: store(CHR); store(*p); } break; default : /* an ordinary char */ store(CHR); store(*p); break; } sp = lp; } if (tagi > 0) return badpat("Unmatched \\("); store(END); sta = OKP; return 0; } static REGEXCHAR *bol; static REGEXCHAR *bopat[MAXTAG]; static REGEXCHAR *eopat[MAXTAG]; #ifdef NEEDPROTOS static REGEXCHAR *pmatch( REGEXCHAR *lp, REGEXCHAR *ap ); #else /* NEEDPROTOS */ static REGEXCHAR *pmatch(); #endif /* NEEDPROTOS */ /* * re_exec: * execute nfa to find a match. * * special cases: (nfa[0]) * BOL * Match only once, starting from the * beginning. * CHR * First locate the character without * calling pmatch, and if found, call * pmatch for the remaining string. * END * re_comp failed, poor luser did not * check for it. Fail fast. * * If a match is found, bopat[0] and eopat[0] are set * to the beginning and the end of the matched fragment, * respectively. * */ int LDAP_CALL re_exec( const char *lp ) { register REGEXCHAR c; register REGEXCHAR *ep = 0; register REGEXCHAR *ap = nfa; bol = (REGEXCHAR*)lp; bopat[0] = 0; bopat[1] = 0; bopat[2] = 0; bopat[3] = 0; bopat[4] = 0; bopat[5] = 0; bopat[6] = 0; bopat[7] = 0; bopat[8] = 0; bopat[9] = 0; switch(*ap) { case BOL: /* anchored: match from BOL only */ ep = pmatch((REGEXCHAR*)lp,ap); break; case CHR: /* ordinary char: locate it fast */ c = *(ap+1); while (*lp && *(REGEXCHAR*)lp != c) lp++; if (!*lp) /* if EOS, fail, else fall thru. */ return 0; default: /* regular matching all the way. */ do { if ((ep = pmatch((REGEXCHAR*)lp,ap))) break; lp++; } while (*lp); break; case END: /* munged automaton. fail always */ return 0; } if (!ep) return 0; bopat[0] = (REGEXCHAR*)lp; eopat[0] = ep; return 1; } /* * pmatch: internal routine for the hard part * * This code is partly snarfed from an early grep written by * David Conroy. The backref and tag stuff, and various other * innovations are by oz. * * special case optimizations: (nfa[n], nfa[n+1]) * CLO ANY * We KNOW .* will match everything upto the * end of line. Thus, directly go to the end of * line, without recursive pmatch calls. As in * the other closure cases, the remaining pattern * must be matched by moving backwards on the * string recursively, to find a match for xy * (x is ".*" and y is the remaining pattern) * where the match satisfies the LONGEST match for * x followed by a match for y. * CLO CHR * We can again scan the string forward for the * single char and at the point of failure, we * execute the remaining nfa recursively, same as * above. * * At the end of a successful match, bopat[n] and eopat[n] * are set to the beginning and end of subpatterns matched * by tagged expressions (n = 1 to 9). * */ #ifndef re_fail extern void re_fail(); #endif /* re_fail */ /* * character classification table for word boundary operators BOW * and EOW. the reason for not using ctype macros is that we can * let the user add into our own table. see re_modw. This table * is not in the bitset form, since we may wish to extend it in the * future for other character classifications. * * TRUE for 0-9 A-Z a-z _ */ static char chrtyp[MAXCHR] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 }; #define HIBIT 0200 #define inascii(x) (0177&(x)) #define iswordc(x) chrtyp[inascii(x)] #define isinset(x,y) (((y)&HIBIT)?0:((x)[((y)&BLKIND)>>3] & bitarr[(y)&BITIND])) /* * skip values for CLO XXX to skip past the closure */ #define ANYSKIP 2 /* [CLO] ANY END ... */ #define CHRSKIP 3 /* [CLO] CHR chr END ... */ #define CCLSKIP 18 /* [CLO] CCL 16bytes END ... */ static REGEXCHAR * pmatch( REGEXCHAR *lp, REGEXCHAR *ap) { register int op, c, n; register REGEXCHAR *e; /* extra pointer for CLO */ register REGEXCHAR *bp; /* beginning of subpat.. */ register REGEXCHAR *ep; /* ending of subpat.. */ REGEXCHAR *are; /* to save the line ptr. */ while ((op = *ap++) != END) switch(op) { case CHR: if (*lp++ != *ap++) return 0; break; case ANY: if (!*lp++) return 0; break; case CCL: c = *lp++; if (!isinset(ap,c)) return 0; ap += BITBLK; break; case BOL: if (lp != bol) return 0; break; case EOL: if (*lp) return 0; break; case BOT: bopat[*ap++] = lp; break; case EOT: eopat[*ap++] = lp; break; case BOW: if ((lp!=bol && iswordc(lp[-1])) || !iswordc(*lp)) return 0; break; case EOW: if (lp==bol || !iswordc(lp[-1]) || iswordc(*lp)) return 0; break; case REF: n = *ap++; bp = bopat[n]; ep = eopat[n]; while (bp < ep) if (*bp++ != *lp++) return 0; break; case CLO: are = lp; switch(*ap) { case ANY: while (*lp) lp++; n = ANYSKIP; break; case CHR: c = *(ap+1); while (*lp && c == *lp) lp++; n = CHRSKIP; break; case CCL: while ((c = *lp) && isinset(ap+1,c)) lp++; n = CCLSKIP; break; default: re_fail("closure: bad nfa.", *ap); return 0; } ap += n; while (lp >= are) { if ((e = pmatch(lp, ap))) return e; --lp; } return 0; default: re_fail("re_exec: bad nfa.", op); return 0; } return lp; } /* * re_modw: * add new characters into the word table to change re_exec's * understanding of what a word should look like. Note that we * only accept additions into the word definition. * * If the string parameter is 0 or null string, the table is * reset back to the default containing A-Z a-z 0-9 _. [We use * the compact bitset representation for the default table] */ static REGEXCHAR deftab[16] = { 0, 0, 0, 0, 0, 0, 0377, 003, 0376, 0377, 0377, 0207, 0376, 0377, 0377, 007 }; void LDAP_CALL re_modw( char *s ) { register int i; if (!s || !*s) { for (i = 0; i < MAXCHR; i++) if (!isinset(deftab,i)) iswordc(i) = 0; } else while(*s) iswordc(*s++) = 1; } /* * re_subs: * substitute the matched portions of the src in dst. * * & substitute the entire matched pattern. * * \digit substitute a subpattern, with the given tag number. * Tags are numbered from 1 to 9. If the particular * tagged subpattern does not exist, null is substituted. */ int LDAP_CALL re_subs( char *src, char *dst) { register char c; register int pin; register REGEXCHAR *bp; register REGEXCHAR *ep; if (!*src || !bopat[0]) return 0; while ((c = *src++)) { switch(c) { case '&': pin = 0; break; case '\\': c = *src++; if (c >= '0' && c <= '9') { pin = c - '0'; break; } default: *dst++ = c; continue; } if ((bp = bopat[pin]) && (ep = eopat[pin])) { while (*bp && bp < ep) *dst++ = *(char*)bp++; if (bp < ep) return 0; } } *dst = (char) 0; return 1; } #ifdef DEBUG /* No printf or exit in 16-bit Windows */ #if defined( _WINDOWS ) && !defined( _WIN32 ) static int LDAP_C printf( const char* pszFormat, ...) { char buf[1024]; va_list arglist; va_start(arglist, pszFormat); vsprintf(buf, pszFormat, arglist); va_end(arglist); OutputDebugString(buf); return 0; } #define exit(v) return #endif /* 16-bit Windows */ #ifdef REGEX_DEBUG static void nfadump( REGEXCHAR *ap); /* * symbolic - produce a symbolic dump of the nfa */ void symbolic( char *s ) { printf("pattern: %s\n", s); printf("nfacode:\n"); nfadump(nfa); } static void nfadump( REGEXCHAR *ap) { register int n; while (*ap != END) switch(*ap++) { case CLO: printf("CLOSURE"); nfadump(ap); switch(*ap) { case CHR: n = CHRSKIP; break; case ANY: n = ANYSKIP; break; case CCL: n = CCLSKIP; break; } ap += n; break; case CHR: printf("\tCHR %c\n",*ap++); break; case ANY: printf("\tANY .\n"); break; case BOL: printf("\tBOL -\n"); break; case EOL: printf("\tEOL -\n"); break; case BOT: printf("BOT: %d\n",*ap++); break; case EOT: printf("EOT: %d\n",*ap++); break; case BOW: printf("BOW\n"); break; case EOW: printf("EOW\n"); break; case REF: printf("REF: %d\n",*ap++); break; case CCL: printf("\tCCL ["); for (n = 0; n < MAXCHR; n++) if (isinset(ap,(REGEXCHAR)n)) { if (n < ' ') printf("^%c", n ^ 0x040); else printf("%c", n); } printf("]\n"); ap += BITBLK; break; default: printf("bad nfa. opcode %o\n", ap[-1]); exit(1); break; } } #endif /* REGEX_DEBUG */ #endif /* DEBUG */ #endif /* macintosh or DOS or _WINDOWS or NEED_BSDREGEX */