file/src/file.h

/*
 * Copyright (c) Ian F. Darwin 1986-1995.
 * Software written by Ian F. Darwin and others;
 * maintained 1995-present by Christos Zoulas and others.
 * 
 * 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 immediately at the beginning of the file, without modification,
 *    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.
 *  
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */
/*
 * file.h - definitions for file(1) program
 * @(#)$File: file.h,v 1.91 2007/03/25 03:13:47 christos Exp $
 */

#ifndef __file_h__
#define __file_h__

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>	/* Include that here, to make sure __P gets defined */
#include <errno.h>
#include <fcntl.h>	/* For open and flags */
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#include <regex.h>
#include <sys/types.h>
/* Do this here and now, because struct stat gets re-defined on solaris */
#include <sys/stat.h>

#define ENABLE_CONDITIONALS

#ifndef MAGIC
#define MAGIC "/etc/magic"
#endif

#ifdef __EMX__
#define PATHSEP	';'
#else
#define PATHSEP	':'
#endif

#define private static
#ifndef protected
#define protected
#endif
#define public

#ifndef __GNUC_PREREQ__
#ifdef __GNUC__
#define	__GNUC_PREREQ__(x, y)						\
	((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) ||			\
	 (__GNUC__ > (x)))
#else
#define	__GNUC_PREREQ__(x, y)	0
#endif
#endif

#ifndef MIN
#define	MIN(a,b)	(((a) < (b)) ? (a) : (b))
#endif

#ifndef HOWMANY
# define HOWMANY (256 * 1024)	/* how much of the file to look at */
#endif
#define MAXMAGIS 8192		/* max entries in /etc/magic */
#define MAXDESC	64		/* max leng of text description */
#define MAXstring 32		/* max leng of "string" types */

#define MAGICNO		0xF11E041C
#define VERSIONNO	4
#define FILE_MAGICSIZE	(32 * 4)

#define	FILE_LOAD	0
#define FILE_CHECK	1
#define FILE_COMPILE	2

struct magic {
	/* Word 1 */
	uint16_t cont_level;	/* level of ">" */
	uint8_t nospflag;	/* supress space character */
	uint8_t flag;
#define INDIR		1	/* if '(...)' appears */
#define OFFADD		2	/* if '>&' or '>...(&' appears */
#define INDIROFFADD	4	/* if '>&(' appears */
#define	UNSIGNED	8	/* comparison is unsigned */

	/* Word 2 */
	uint8_t reln;		/* relation (0=eq, '>'=gt, etc) */
	uint8_t vallen;		/* length of string value, if any */
	uint8_t type;		/* int, short, long or string. */
	uint8_t in_type;	/* type of indirrection */
#define 			FILE_INVALID	0
#define 			FILE_BYTE	1
#define				FILE_SHORT	2
#define				FILE_DEFAULT	3
#define				FILE_LONG	4
#define				FILE_STRING	5
#define				FILE_DATE	6
#define				FILE_BESHORT	7
#define				FILE_BELONG	8
#define				FILE_BEDATE	9
#define				FILE_LESHORT	10
#define				FILE_LELONG	11
#define				FILE_LEDATE	12
#define				FILE_PSTRING	13
#define				FILE_LDATE	14
#define				FILE_BELDATE	15
#define				FILE_LELDATE	16
#define				FILE_REGEX	17
#define				FILE_BESTRING16	18
#define				FILE_LESTRING16	19
#define				FILE_SEARCH	20
#define				FILE_MEDATE	21
#define				FILE_MELDATE	22
#define				FILE_MELONG	23
#define				FILE_QUAD	24
#define				FILE_LEQUAD	25
#define				FILE_BEQUAD	26
#define				FILE_QDATE	27
#define				FILE_LEQDATE	28
#define				FILE_BEQDATE	29
#define				FILE_QLDATE	30
#define				FILE_LEQLDATE	31
#define				FILE_BEQLDATE	32
#define				FILE_NAMES_SIZE	33/* size of array to contain all names */

#define IS_STRING(t) \
	((t) == FILE_STRING || \
	 (t) == FILE_PSTRING || \
	 (t) == FILE_BESTRING16 || \
	 (t) == FILE_LESTRING16 || \
	 (t) == FILE_REGEX || \
	 (t) == FILE_SEARCH || \
	 (t) == FILE_DEFAULT)

#define FILE_FMT_NONE 0
#define FILE_FMT_NUM  1 /* "cduxXi" */
#define FILE_FMT_STR  2 /* "s" */
#define FILE_FMT_QUAD 3 /* "ll" */

	/* Word 3 */
	uint8_t in_op;		/* operator for indirection */
	uint8_t mask_op;	/* operator for mask */
#ifdef ENABLE_CONDITIONALS
	uint8_t cond;		/* conditional type */
	uint8_t dummy1;	
#else
	uint8_t dummy1;	
	uint8_t dummy2;	
#endif

#define				FILE_OPS	"&|^+-*/%"
#define				FILE_OPAND	0
#define				FILE_OPOR	1
#define				FILE_OPXOR	2
#define				FILE_OPADD	3
#define				FILE_OPMINUS	4
#define				FILE_OPMULTIPLY	5
#define				FILE_OPDIVIDE	6
#define				FILE_OPMODULO	7
#define				FILE_OPS_MASK	0x07 /* mask for above ops */
#define				FILE_UNUSED_1	0x08
#define				FILE_UNUSED_2	0x10
#define				FILE_UNUSED_3	0x20
#define				FILE_OPINVERSE	0x40
#define				FILE_OPINDIRECT	0x80

#ifdef ENABLE_CONDITIONALS
#define				COND_NONE	0
#define				COND_IF		1
#define				COND_ELIF	2
#define				COND_ELSE	3
#endif /* ENABLE_CONDITIONALS */

	/* Word 4 */
	uint32_t offset;	/* offset to magic number */
	/* Word 5 */
	int32_t in_offset;	/* offset from indirection */
	/* Word 6 */
	uint32_t lineno;	/* line number in magic file */
	/* Word 7,8 */
	union {
		uint64_t _mask;	/* for use with numeric and date types */
		struct {
			uint32_t _count;	/* repeat/line count */
			uint32_t _flags;	/* modifier flags */
		} _s;		/* for use with string types */
	} _u;
#define num_mask _u._mask
#define str_count _u._s._count
#define str_flags _u._s._flags

	/* Words 9-16 */
	union VALUETYPE {
		uint8_t b;
		uint16_t h;
		uint32_t l;
		uint64_t q;
		uint8_t hs[2];	/* 2 bytes of a fixed-endian "short" */
		uint8_t hl[4];	/* 4 bytes of a fixed-endian "long" */
		uint8_t hq[8];	/* 8 bytes of a fixed-endian "quad" */
		char s[MAXstring];	/* the search string or regex pattern */
	} value;		/* either number or string */
	/* Words 17..31 */
	char desc[MAXDESC];	/* description */
};

#define BIT(A)   (1 << (A))
#define STRING_COMPACT_BLANK		BIT(0)
#define STRING_COMPACT_OPTIONAL_BLANK	BIT(1)
#define STRING_IGNORE_LOWERCASE		BIT(2)
#define STRING_IGNORE_UPPERCASE		BIT(3)
#define REGEX_OFFSET_START		BIT(4)
#define CHAR_COMPACT_BLANK		'B'
#define CHAR_COMPACT_OPTIONAL_BLANK	'b'
#define CHAR_IGNORE_LOWERCASE		'c'
#define CHAR_IGNORE_UPPERCASE		'C'
#define CHAR_REGEX_OFFSET_START		's'
#define STRING_IGNORE_CASE		(STRING_IGNORE_LOWERCASE|STRING_IGNORE_UPPERCASE)


/* list of magic entries */
struct mlist {
	struct magic *magic;		/* array of magic entries */
	uint32_t nmagic;			/* number of entries in array */
	int mapped;  /* allocation type: 0 => apprentice_file
		      *                  1 => apprentice_map + malloc
		      *                  2 => apprentice_map + mmap */
	struct mlist *next, *prev;
};

struct magic_set {
	struct mlist *mlist;
	struct cont {
		size_t len;
		struct level_info {
			int32_t off;
			int got_match;
#ifdef ENABLE_CONDITIONALS
			int last_match;
			int last_cond;	/* used for error checking by parse() */
#endif
		} *li;
	} c;
	struct out {
		/* Accumulation buffer */
		char *buf;
		char *ptr;
		size_t left;
		size_t size;
		/* Printable buffer */
		char *pbuf;
		size_t psize;
	} o;
	uint32_t offset;
	int error;
	int flags;
	int haderr;
	const char *file;
	size_t line;			/* current magic line number */

	/* data for searches */
	struct {
		const char *s;		/* start of search in original source */
		size_t s_len;		/* length of search region */
		size_t offset;		/* starting offset in source: XXX - should this be off_t? */
		size_t rm_len;		/* match length */
	} search;

	union VALUETYPE ms_value;	/* either number or string */
};

struct stat;
protected const char *file_fmttime(uint32_t, int);
protected int file_buffer(struct magic_set *, int, const char *, const void *,
    size_t);
protected int file_fsmagic(struct magic_set *, const char *, struct stat *);
protected int file_pipe2file(struct magic_set *, int, const void *, size_t);
protected int file_printf(struct magic_set *, const char *, ...);
protected int file_reset(struct magic_set *);
protected int file_tryelf(struct magic_set *, int, const unsigned char *,
    size_t);
protected int file_zmagic(struct magic_set *, int, const char *,
    const unsigned char *, size_t);
protected int file_ascmagic(struct magic_set *, const unsigned char *, size_t);
protected int file_is_tar(struct magic_set *, const unsigned char *, size_t);
protected int file_softmagic(struct magic_set *, const unsigned char *, size_t);
protected struct mlist *file_apprentice(struct magic_set *, const char *, int);
protected uint64_t file_signextend(struct magic_set *, struct magic *,
    uint64_t);
protected void file_delmagic(struct magic *, int type, size_t entries);
protected void file_badread(struct magic_set *);
protected void file_badseek(struct magic_set *);
protected void file_oomem(struct magic_set *, size_t);
protected void file_error(struct magic_set *, int, const char *, ...);
protected void file_magerror(struct magic_set *, const char *, ...);
protected void file_magwarn(struct magic_set *, const char *, ...);
protected void file_mdump(struct magic *);
protected void file_showstr(FILE *, const char *, size_t);
protected size_t file_mbswidth(const char *);
protected const char *file_getbuffer(struct magic_set *);
protected ssize_t sread(int, void *, size_t, int);
protected int file_check_mem(struct magic_set *, unsigned int);

#ifndef COMPILE_ONLY
extern const char *file_names[];
extern const size_t file_nnames;
#endif

#ifndef HAVE_STRERROR
extern int sys_nerr;
extern char *sys_errlist[];
#define strerror(e) \
	(((e) >= 0 && (e) < sys_nerr) ? sys_errlist[(e)] : "Unknown error")
#endif

#ifndef HAVE_STRTOUL
#define strtoul(a, b, c)	strtol(a, b, c)
#endif

#ifndef HAVE_SNPRINTF
int snprintf(char *, size_t, const char *, ...);
#endif

#if defined(HAVE_MMAP) && defined(HAVE_SYS_MMAN_H) && !defined(QUICK)
#define QUICK
#endif

#ifndef O_BINARY
#define O_BINARY	0
#endif

#define FILE_RCSID(id) \
static const char *rcsid(const char *p) { \
	return rcsid(p = id); \
}

#endif /* __file_h__ */