-/*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
- * Reserved. This file contains Original Code and/or Modifications of
- * Original Code as defined in and that are subject to the Apple Public
- * Source License Version 1.1 (the "License"). You may not use this file
- * except in compliance with the License. Please obtain a copy of the
- * License at http://www.apple.com/publicsource and read it before using
- * this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-/* $OpenBSD: softmagic.c,v 1.3 1997/02/09 23:58:36 millert Exp $ */
-
-/*
- * softmagic - interpret variable magic from /etc/magic
- *
- * Copyright (c) Ian F. Darwin, 1987.
- * Written by Ian F. Darwin.
- *
- * This software is not subject to any license of the American Telephone
- * and Telegraph Company or of the Regents of the University of California.
- *
- * Permission is granted to anyone to use this software for any purpose on
- * any computer system, and to alter it and redistribute it freely, subject
- * to the following restrictions:
- *
- * 1. The author is not responsible for the consequences of use of this
- * software, no matter how awful, even if they arise from flaws in it.
- *
- * 2. The origin of this software must not be misrepresented, either by
- * explicit claim or by omission. Since few users ever read sources,
- * credits must appear in the documentation.
- *
- * 3. Altered versions must be plainly marked as such, and must not be
- * misrepresented as being the original software. Since few users
- * ever read sources, credits must appear in the documentation.
- *
- * 4. This notice may not be removed or altered.
- */
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <time.h>
-#include <sys/types.h>
-
-#include "file.h"
-
-#ifndef lint
-#if 0
-static char *moduleid = "$OpenBSD: softmagic.c,v 1.3 1997/02/09 23:58:36 millert Exp $";
-#endif
-#endif /* lint */
-
-static int match __P((unsigned char *, int));
-static int mget __P((union VALUETYPE *,
- unsigned char *, struct magic *, int));
-static int mcheck __P((union VALUETYPE *, struct magic *));
-static int32 mprint __P((union VALUETYPE *, struct magic *));
-static void mdebug __P((int32, char *, int));
-static int mconvert __P((union VALUETYPE *, struct magic *));
-
-/*
- * softmagic - lookup one file in database
- * (already read from /etc/magic by apprentice.c).
- * Passed the name and FILE * of one file to be typed.
- */
-/*ARGSUSED1*/ /* nbytes passed for regularity, maybe need later */
-int
-softmagic(buf, nbytes)
-unsigned char *buf;
-int nbytes;
-{
- if (match(buf, nbytes))
- return 1;
-
- return 0;
-}
-
-/*
- * Go through the whole list, stopping if you find a match. Process all
- * the continuations of that match before returning.
- *
- * We support multi-level continuations:
- *
- * At any time when processing a successful top-level match, there is a
- * current continuation level; it represents the level of the last
- * successfully matched continuation.
- *
- * Continuations above that level are skipped as, if we see one, it
- * means that the continuation that controls them - i.e, the
- * lower-level continuation preceding them - failed to match.
- *
- * Continuations below that level are processed as, if we see one,
- * it means we've finished processing or skipping higher-level
- * continuations under the control of a successful or unsuccessful
- * lower-level continuation, and are now seeing the next lower-level
- * continuation and should process it. The current continuation
- * level reverts to the level of the one we're seeing.
- *
- * Continuations at the current level are processed as, if we see
- * one, there's no lower-level continuation that may have failed.
- *
- * If a continuation matches, we bump the current continuation level
- * so that higher-level continuations are processed.
- */
-static int
-match(s, nbytes)
-unsigned char *s;
-int nbytes;
-{
- int magindex = 0;
- int cont_level = 0;
- int need_separator = 0;
- union VALUETYPE p;
- static int32 *tmpoff = NULL;
- static size_t tmplen = 0;
- int32 oldoff = 0;
-
- if (tmpoff == NULL)
- if ((tmpoff = (int32 *) malloc(tmplen = 20)) == NULL)
- error("out of memory\n");
-
- for (magindex = 0; magindex < nmagic; magindex++) {
- /* if main entry matches, print it... */
- if (!mget(&p, s, &magic[magindex], nbytes) ||
- !mcheck(&p, &magic[magindex])) {
- /*
- * main entry didn't match,
- * flush its continuations
- */
- while (magindex < nmagic &&
- magic[magindex + 1].cont_level != 0)
- magindex++;
- continue;
- }
-
- tmpoff[cont_level] = mprint(&p, &magic[magindex]);
- /*
- * If we printed something, we'll need to print
- * a blank before we print something else.
- */
- if (magic[magindex].desc[0])
- need_separator = 1;
- /* and any continuations that match */
- if (++cont_level >= tmplen)
- if ((tmpoff = (int32 *) realloc(tmpoff,
- tmplen += 20)) == NULL)
- error("out of memory\n");
- while (magic[magindex+1].cont_level != 0 &&
- ++magindex < nmagic) {
- if (cont_level >= magic[magindex].cont_level) {
- if (cont_level > magic[magindex].cont_level) {
- /*
- * We're at the end of the level
- * "cont_level" continuations.
- */
- cont_level = magic[magindex].cont_level;
- }
- if (magic[magindex].flag & ADD) {
- oldoff=magic[magindex].offset;
- magic[magindex].offset += tmpoff[cont_level-1];
- }
- if (mget(&p, s, &magic[magindex], nbytes) &&
- mcheck(&p, &magic[magindex])) {
- /*
- * This continuation matched.
- * Print its message, with
- * a blank before it if
- * the previous item printed
- * and this item isn't empty.
- */
- /* space if previous printed */
- if (need_separator
- && (magic[magindex].nospflag == 0)
- && (magic[magindex].desc[0] != '\0')
- ) {
- (void) putchar(' ');
- need_separator = 0;
- }
- tmpoff[cont_level] = mprint(&p, &magic[magindex]);
- if (magic[magindex].desc[0])
- need_separator = 1;
-
- /*
- * If we see any continuations
- * at a higher level,
- * process them.
- */
- if (++cont_level >= tmplen)
- if ((tmpoff =
- (int32 *) realloc(tmpoff,
- tmplen += 20)) == NULL)
- error("out of memory\n");
- }
- if (magic[magindex].flag & ADD) {
- magic[magindex].offset = oldoff;
- }
- }
- }
- return 1; /* all through */
- }
- return 0; /* no match at all */
-}
-
-static int32
-mprint(p, m)
-union VALUETYPE *p;
-struct magic *m;
-{
- char *pp, *rt;
- uint32 v;
- int32 t=0 ;
-
-
- switch (m->type) {
- case BYTE:
- v = p->b;
- v = signextend(m, v) & m->mask;
- (void) printf(m->desc, (unsigned char) v);
- t = m->offset + sizeof(char);
- break;
-
- case SHORT:
- case BESHORT:
- case LESHORT:
- v = p->h;
- v = signextend(m, v) & m->mask;
- (void) printf(m->desc, (unsigned short) v);
- t = m->offset + sizeof(short);
- break;
-
- case LONG:
- case BELONG:
- case LELONG:
- v = p->l;
- v = signextend(m, v) & m->mask;
- (void) printf(m->desc, (uint32) v);
- t = m->offset + sizeof(int32);
- break;
-
- case STRING:
- if (m->reln == '=') {
- (void) printf(m->desc, m->value.s);
- t = m->offset + strlen(m->value.s);
- }
- else {
- if (*m->value.s == '\0') {
- char *cp = strchr(p->s,'\n');
- if (cp)
- *cp = '\0';
- }
- (void) printf(m->desc, p->s);
- t = m->offset + strlen(p->s);
- }
- break;
-
- case DATE:
- case BEDATE:
- case LEDATE:
- pp = ctime((time_t*) &p->l);
- if ((rt = strchr(pp, '\n')) != NULL)
- *rt = '\0';
- (void) printf(m->desc, pp);
- t = m->offset + sizeof(time_t);
- break;
-
- default:
- error("invalid m->type (%d) in mprint().\n", m->type);
- /*NOTREACHED*/
- }
- return(t);
-}
-
-/*
- * Convert the byte order of the data we are looking at
- */
-static int
-mconvert(p, m)
-union VALUETYPE *p;
-struct magic *m;
-{
- switch (m->type) {
- case BYTE:
- case SHORT:
- case LONG:
- case DATE:
- return 1;
- case STRING:
- {
- char *ptr;
-
- /* Null terminate and eat the return */
- p->s[sizeof(p->s) - 1] = '\0';
- if ((ptr = strchr(p->s, '\n')) != NULL)
- *ptr = '\0';
- return 1;
- }
- case BESHORT:
- p->h = (short)((p->hs[0]<<8)|(p->hs[1]));
- return 1;
- case BELONG:
- case BEDATE:
- p->l = (int32)
- ((p->hl[0]<<24)|(p->hl[1]<<16)|(p->hl[2]<<8)|(p->hl[3]));
- return 1;
- case LESHORT:
- p->h = (short)((p->hs[1]<<8)|(p->hs[0]));
- return 1;
- case LELONG:
- case LEDATE:
- p->l = (int32)
- ((p->hl[3]<<24)|(p->hl[2]<<16)|(p->hl[1]<<8)|(p->hl[0]));
- return 1;
- default:
- error("invalid type %d in mconvert().\n", m->type);
- return 0;
- }
-}
-
-
-static void
-mdebug(offset, str, len)
-int32 offset;
-char *str;
-int len;
-{
- (void) fprintf(stderr, "mget @%d: ", offset);
- showstr(stderr, (char *) str, len);
- (void) fputc('\n', stderr);
- (void) fputc('\n', stderr);
-}
-
-static int
-mget(p, s, m, nbytes)
-union VALUETYPE* p;
-unsigned char *s;
-struct magic *m;
-int nbytes;
-{
- int32 offset = m->offset;
-
- if (offset + sizeof(union VALUETYPE) <= nbytes)
- memcpy(p, s + offset, sizeof(union VALUETYPE));
- else {
- /*
- * the usefulness of padding with zeroes eludes me, it
- * might even cause problems
- */
- int32 have = nbytes - offset;
- memset(p, 0, sizeof(union VALUETYPE));
- if (have > 0)
- memcpy(p, s + offset, have);
- }
-
-
- if (debug) {
- mdebug(offset, (char *) p, sizeof(union VALUETYPE));
- mdump(m);
- }
-
- if (!mconvert(p, m))
- return 0;
-
- if (m->flag & INDIR) {
-
- switch (m->in.type) {
- case BYTE:
- offset = p->b + m->in.offset;
- break;
- case SHORT:
- offset = p->h + m->in.offset;
- break;
- case LONG:
- offset = p->l + m->in.offset;
- break;
- }
-
- if (offset + sizeof(union VALUETYPE) > nbytes)
- return 0;
-
- memcpy(p, s + offset, sizeof(union VALUETYPE));
-
- if (debug) {
- mdebug(offset, (char *) p, sizeof(union VALUETYPE));
- mdump(m);
- }
-
- if (!mconvert(p, m))
- return 0;
- }
- return 1;
-}
-
-static int
-mcheck(p, m)
-union VALUETYPE* p;
-struct magic *m;
-{
- register uint32 l = m->value.l;
- register uint32 v;
- int matched;
-
- if ( (m->value.s[0] == 'x') && (m->value.s[1] == '\0') ) {
- fprintf(stderr, "BOINK");
- return 1;
- }
-
-
- switch (m->type) {
- case BYTE:
- v = p->b;
- break;
-
- case SHORT:
- case BESHORT:
- case LESHORT:
- v = p->h;
- break;
-
- case LONG:
- case BELONG:
- case LELONG:
- case DATE:
- case BEDATE:
- case LEDATE:
- v = p->l;
- break;
-
- case STRING:
- l = 0;
- /* What we want here is:
- * v = strncmp(m->value.s, p->s, m->vallen);
- * but ignoring any nulls. bcmp doesn't give -/+/0
- * and isn't universally available anyway.
- */
- v = 0;
- {
- register unsigned char *a = (unsigned char*)m->value.s;
- register unsigned char *b = (unsigned char*)p->s;
- register int len = m->vallen;
-
- while (--len >= 0)
- if ((v = *b++ - *a++) != '\0')
- break;
- }
- break;
- default:
- error("invalid type %d in mcheck().\n", m->type);
- return 0;/*NOTREACHED*/
- }
-
- v = signextend(m, v) & m->mask;
-
- switch (m->reln) {
- case 'x':
- if (debug)
- (void) fprintf(stderr, "%u == *any* = 1\n", v);
- matched = 1;
- break;
-
- case '!':
- matched = v != l;
- if (debug)
- (void) fprintf(stderr, "%u != %u = %d\n",
- v, l, matched);
- break;
-
- case '=':
- matched = v == l;
- if (debug)
- (void) fprintf(stderr, "%u == %u = %d\n",
- v, l, matched);
- break;
-
- case '>':
- if (m->flag & UNSIGNED) {
- matched = v > l;
- if (debug)
- (void) fprintf(stderr, "%u > %u = %d\n",
- v, l, matched);
- }
- else {
- matched = (int32) v > (int32) l;
- if (debug)
- (void) fprintf(stderr, "%d > %d = %d\n",
- v, l, matched);
- }
- break;
-
- case '<':
- if (m->flag & UNSIGNED) {
- matched = v < l;
- if (debug)
- (void) fprintf(stderr, "%u < %u = %d\n",
- v, l, matched);
- }
- else {
- matched = (int32) v < (int32) l;
- if (debug)
- (void) fprintf(stderr, "%d < %d = %d\n",
- v, l, matched);
- }
- break;
-
- case '&':
- matched = (v & l) == l;
- if (debug)
- (void) fprintf(stderr, "((%x & %x) == %x) = %d\n",
- v, l, l, matched);
- break;
-
- case '^':
- matched = (v & l) != l;
- if (debug)
- (void) fprintf(stderr, "((%x & %x) != %x) = %d\n",
- v, l, l, matched);
- break;
-
- default:
- matched = 0;
- error("mcheck: can't happen: invalid relation %d.\n", m->reln);
- break;/*NOTREACHED*/
- }
-
- return matched;
-}
projects / apple / file_cmds.git / blobdiff