/*-
  * This code is derived from OpenBSD's libc/regex, original license follows:
  *
  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
  * Copyright (c) 1992, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Henry Spencer.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	@(#)regerror.c	8.4 (Berkeley) 3/20/94
  */
 
 #include <sys/types.h>
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>
 #include <limits.h>
 #include <stdlib.h>

 #include "clamav.h"

 #include "others.h"
 #include "regex.h"
 
 #include "utils.h"
 
 static const char *regatoi(const regex_t *, char *, int);
 
 static struct rerr {
 	int code;
 	const char *name;
 	const char *explain;
 } rerrs[] = {
 	{ REG_NOMATCH,	"REG_NOMATCH",	"cli_regexec() failed to match" },
 	{ REG_BADPAT,	"REG_BADPAT",	"invalid regular expression" },
 	{ REG_ECOLLATE,	"REG_ECOLLATE",	"invalid collating element" },
 	{ REG_ECTYPE,	"REG_ECTYPE",	"invalid character class" },
 	{ REG_EESCAPE,	"REG_EESCAPE",	"trailing backslash (\\)" },
 	{ REG_ESUBREG,	"REG_ESUBREG",	"invalid backreference number" },
 	{ REG_EBRACK,	"REG_EBRACK",	"brackets ([ ]) not balanced" },
 	{ REG_EPAREN,	"REG_EPAREN",	"parentheses not balanced" },
 	{ REG_EBRACE,	"REG_EBRACE",	"braces not balanced" },
 	{ REG_BADBR,	"REG_BADBR",	"invalid repetition count(s)" },
 	{ REG_ERANGE,	"REG_ERANGE",	"invalid character range" },
 	{ REG_ESPACE,	"REG_ESPACE",	"out of memory" },
 	{ REG_BADRPT,	"REG_BADRPT",	"repetition-operator operand invalid" },
 	{ REG_EMPTY,	"REG_EMPTY",	"empty (sub)expression" },
 	{ REG_ASSERT,	"REG_ASSERT",	"\"can't happen\" -- you found a bug" },
 	{ REG_INVARG,	"REG_INVARG",	"invalid argument to regex routine" },
 	{ 0,		"",		"*** unknown regexp error code ***" }
 };
 
 /*
  - cli_regerror - the interface to error numbers
  = extern size_t cli_regerror(int, const regex_t *, char *, size_t);
  */
 /* ARGSUSED */
 size_t
 cli_regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
 {
 	struct rerr *r;
 	size_t len;
 	int target = errcode &~ REG_ITOA;
 	const char *s;
 	char convbuf[50];
 
 	if (errcode == REG_ATOI)
 		s = regatoi(preg, convbuf, sizeof convbuf);
 	else {
 		for (r = rerrs; r->code != 0; r++)
 			if (r->code == target)
 				break;
 	
 		if (errcode&REG_ITOA) {
 			if (r->code != 0) {
 				assert(strlen(r->name) < sizeof(convbuf));
 				(void) cli_strlcpy(convbuf, r->name, sizeof convbuf);
 			} else
 				(void)snprintf(convbuf, sizeof convbuf,
 				    "REG_0x%x", target);
 			s = convbuf;
 		} else
 			s = r->explain;
 	}
 
 	len = strlen(s) + 1;
 	if (errbuf_size > 0) {
 		cli_strlcpy(errbuf, s, errbuf_size);
 	}
 
 	return(len);
 }
 
 /*
  - regatoi - internal routine to implement REG_ATOI
  */
 static const char *
 regatoi(const regex_t *preg, char *localbuf, int localbufsize)
 {
 	struct rerr *r;
 
 	for (r = rerrs; r->code != 0; r++)
 		if (strcmp(r->name, preg->re_endp) == 0)
 			break;
 	if (r->code == 0)
 		return("0");
 
 	(void)snprintf(localbuf, localbufsize, "%d", r->code);
 	return(localbuf);
 }