file/src/softmagic.c

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/*@-compdef@*/
/*@-evalorder@*/
/*@-sizeoftype@*/
/*@-uniondef@*/
/*@-usereleased@*/
/*
 * 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.
 */
/*
 * softmagic - interpret variable magic from MAGIC
 */

#include "file.h"
#include "magic.h"
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>
#include <regex.h>


#ifndef lint
FILE_RCSID("@(#)$Id: softmagic.c,v 1.76 2005/10/17 19:04:36 christos Exp $")
#endif  /* lint */

private int match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
    const unsigned char *s, size_t nbytes)
        /*@globals fileSystem @*/
        /*@modifies ms, magic, fileSystem @*/;
private int mget(struct magic_set *ms, union VALUETYPE *p, const unsigned char *s,
    struct magic *m, size_t nbytes, unsigned int cont_level)
        /*@globals fileSystem @*/
        /*@modifies ms, p, m, fileSystem @*/;
private int mymcheck(struct magic_set *ms, union VALUETYPE *p, struct magic *m)
        /*@globals fileSystem @*/
        /*@modifies ms, p, m, fileSystem @*/;
private int32_t mprint(struct magic_set *ms, union VALUETYPE *p, struct magic *m)       
        /*@globals fileSystem @*/
        /*@modifies ms, p, fileSystem @*/;
private void mdebug(uint32_t offset, const char *str, size_t len)
        /*@globals fileSystem @*/
        /*@modifies fileSystem @*/;
private int mcopy(struct magic_set *ms, union VALUETYPE *p, int type, int indir,
    const unsigned char *s, size_t offset, size_t nbytes)
        /*@modifies ms, p @*/;
private int mconvert(struct magic_set *ms, union VALUETYPE *p, struct magic *m)
        /*@modifies ms, p @*/;
private int check_mem(struct magic_set *ms, unsigned int level)
        /*@modifies ms @*/;

/*
 * softmagic - lookup one file in database 
 * (already read from MAGIC by apprentice.c).
 * Passed the name and FILE * of one file to be typed.
 */
/*ARGSUSED1*/           /* nbytes passed for regularity, maybe need later */
protected int
file_softmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes)
{
        struct mlist *ml;
        for (ml = ms->mlist->next; ml != ms->mlist; ml = ml->next)
                if (match(ms, ml->magic, ml->nmagic, 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.
 */
private int
match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
    const unsigned char *s, size_t nbytes)
{
        uint32_t magindex = 0;
        unsigned int cont_level = 0;
        int need_separator = 0;
        union VALUETYPE p;
        int32_t oldoff = 0;
        int returnval = 0; /* if a match is found it is set to 1*/
        int firstline = 1; /* a flag to print X\n  X\n- X */

        if (check_mem(ms, cont_level) == -1)
                return -1;

        for (magindex = 0; magindex < nmagic; magindex++) {
                /* if main entry matches, print it... */
                int flush = !mget(ms, &p, s, &magic[magindex], nbytes,
                    cont_level);
                if (flush) {
                        if (magic[magindex].reln == '!') flush = 0;
                } else {        
                        switch (mymcheck(ms, &p, &magic[magindex])) {
                        case -1:
                                return -1;
                        case 0:
                                flush++;
                                /*@switchbreak@*/ break;
                        default:
                                /*@switchbreak@*/ break;
                        }
                }
                if (flush) {
                        /* 
                         * main entry didn't match,
                         * flush its continuations
                         */
                        while (magindex < nmagic - 1 &&
                               magic[magindex + 1].cont_level != 0)
                               magindex++;
                        continue;
                }

                if (!firstline) { /* we found another match */
                        /* put a newline and '-' to do some simple formatting*/
                        if (file_printf(ms, "\n- ") == -1)
                                return -1;
                }

                if ((ms->c.off[cont_level] = mprint(ms, &p, &magic[magindex]))
                    == -1)
                        return -1;
                /*
                 * 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 (check_mem(ms, ++cont_level) == -1)
                        return -1;

                while (magic[magindex+1].cont_level != 0 && 
                       ++magindex < nmagic) {
                        if (cont_level < magic[magindex].cont_level)
                                /*@innercontinue@*/ continue;
                        if (cont_level > magic[magindex].cont_level) {
                                /*
                                 * We're at the end of the level
                                 * "cont_level" continuations.
                                 */
                                cont_level = magic[magindex].cont_level;
                        }
                        oldoff = magic[magindex].offset;
                        if (magic[magindex].flag & OFFADD) {
                                magic[magindex].offset +=
                                    ms->c.off[cont_level - 1];
                        }

                        flush = !mget(ms, &p, s, &magic[magindex], nbytes,
                            cont_level);
                        if (flush && magic[magindex].reln != '!')
                                goto done;
                                
                        switch (flush ? 1 : mymcheck(ms, &p, &magic[magindex])) {
                        case -1:
                                return -1;
                        case 0:
                                /*@switchbreak@*/ break;
                        default:
                                /*
                                 * 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')) {
                                        if (file_printf(ms, " ") == -1)
                                                return -1;
                                        need_separator = 0;
                                }
                                if ((ms->c.off[cont_level] = mprint(ms, &p,
                                    &magic[magindex])) == -1)
                                        return -1;
                                if (magic[magindex].desc[0])
                                        need_separator = 1;

                                /*
                                 * If we see any continuations
                                 * at a higher level,
                                 * process them.
                                 */
                                if (check_mem(ms, ++cont_level) == -1)
                                        return -1;
                        }
done:
                        magic[magindex].offset = oldoff;
                }
                firstline = 0;
                returnval = 1;
                if ((ms->flags & MAGIC_CONTINUE) == 0) {
                        return 1; /* don't keep searching */
                }                       
        }
        return returnval;  /* This is hit if -k is set or there is no match */
}

private int
check_mem(struct magic_set *ms, unsigned int level)
{
        size_t len;

        if (level < ms->c.len)
                return 0;

        len = (ms->c.len += 20) * sizeof(*ms->c.off);
        ms->c.off = (ms->c.off == NULL) ? malloc(len) : realloc(ms->c.off, len);
        if (ms->c.off != NULL)
                return 0;
        file_oomem(ms);
        return -1;
}

private int32_t
mprint(struct magic_set *ms, union VALUETYPE *p, struct magic *m)
{
        uint32_t v;
        int32_t t=0 ;


        switch (m->type) {
        case FILE_BYTE:
                v = file_signextend(ms, m, (size_t)p->b);
                if (file_printf(ms, m->desc, (unsigned char) v) == -1)
                        return -1;
                t = m->offset + sizeof(char);
                break;

        case FILE_SHORT:
        case FILE_BESHORT:
        case FILE_LESHORT:
                v = file_signextend(ms, m, (size_t)p->h);
                if (file_printf(ms, m->desc, (unsigned short) v) == -1)
                        return -1;
                t = m->offset + sizeof(short);
                break;

        case FILE_LONG:
        case FILE_BELONG:
        case FILE_LELONG:
                v = file_signextend(ms, m, p->l);
                if (file_printf(ms, m->desc, (uint32_t) v) == -1)
                        return -1;
                t = m->offset + sizeof(int32_t);
                break;

        case FILE_STRING:
        case FILE_PSTRING:
        case FILE_BESTRING16:
        case FILE_LESTRING16:
                if (m->reln == '=' || m->reln == '!') {
                        if (file_printf(ms, m->desc, m->value.s) == -1)
                                return -1;
                        t = m->offset + m->vallen;
                }
                else {
                        if (*m->value.s == '\0') {
                                char *cp = strchr(p->s,'\n');
                                if (cp)
                                        *cp = '\0';
                        }
                        if (file_printf(ms, m->desc, p->s) == -1)
                                return -1;
                        t = m->offset + strlen(p->s);
                }
                break;

        case FILE_DATE:
        case FILE_BEDATE:
        case FILE_LEDATE:
                if (file_printf(ms, m->desc, file_fmttime(p->l, 1)) == -1)
                        return -1;
                t = m->offset + sizeof(time_t);
                break;

        case FILE_LDATE:
        case FILE_BELDATE:
        case FILE_LELDATE:
                if (file_printf(ms, m->desc, file_fmttime(p->l, 0)) == -1)
                        return -1;
                t = m->offset + sizeof(time_t);
                break;
        case FILE_REGEX:
                if (file_printf(ms, m->desc, p->s) == -1)
                        return -1;
                t = m->offset + strlen(p->s);
                break;
        case FILE_SEARCH:
                if (file_printf(ms, m->desc, m->value.s) == -1)
                        return -1;
                t = m->offset + m->vallen;
                break;

        default:
                file_error(ms, 0, "invalid m->type (%d) in mprint()", m->type);
                return -1;
        }
        return(t);
}

/*
 * Convert the byte order of the data we are looking at
 * While we're here, let's apply the mask operation
 * (unless you have a better idea)
 */
private int
mconvert(struct magic_set *ms, union VALUETYPE *p, struct magic *m)
{
        switch (m->type) {
        case FILE_BYTE:
                if (m->mask)
                        switch (m->mask_op & 0x7F) {
                        case FILE_OPAND:
                                p->b &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->b |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->b ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->b += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->b -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->b *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->b /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->b %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->b = ~p->b;
                return 1;
        case FILE_SHORT:
                if (m->mask)
                        switch (m->mask_op & 0x7F) {
                        case FILE_OPAND:
                                p->h &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->h |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->h ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->h += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->h -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->h *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->h /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->h %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->h = ~p->h;
                return 1;
        case FILE_LONG:
        case FILE_DATE:
        case FILE_LDATE:
                if (m->mask)
                        switch (m->mask_op & 0x7F) {
                        case FILE_OPAND:
                                p->l &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->l |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->l ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->l += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->l -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->l *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->l /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->l %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->l = ~p->l;
                return 1;
        case FILE_STRING:
        case FILE_BESTRING16:
        case FILE_LESTRING16:
                {
                        size_t len;

                        /* Null terminate and eat *trailing* return */
                        p->s[sizeof(p->s) - 1] = '\0';
                        len = strlen(p->s);
                        if (len-- && p->s[len] == '\n')
                                p->s[len] = '\0';
                        return 1;
                }
        case FILE_PSTRING:
                {
                        char *ptr1 = p->s, *ptr2 = ptr1 + 1;
                        size_t len = *p->s;
                        if (len >= sizeof(p->s))
                                len = sizeof(p->s) - 1;
                        while (len--)
                                *ptr1++ = *ptr2++;
                        *ptr1 = '\0';
                        len = strlen(p->s);
                        if (len-- && p->s[len] == '\n')
                                p->s[len] = '\0';
                        return 1;
                }
        case FILE_BESHORT:
                p->h = (short)((p->hs[0]<<8)|(p->hs[1]));
                if (m->mask)
                        switch (m->mask_op&0x7F) {
                        case FILE_OPAND:
                                p->h &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->h |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->h ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->h += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->h -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->h *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->h /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->h %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->h = ~p->h;
                return 1;
        case FILE_BELONG:
        case FILE_BEDATE:
        case FILE_BELDATE:
                p->l = (int32_t)
                    ((p->hl[0]<<24)|(p->hl[1]<<16)|(p->hl[2]<<8)|(p->hl[3]));
                if (m->mask)
                        switch (m->mask_op&0x7F) {
                        case FILE_OPAND:
                                p->l &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->l |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->l ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->l += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->l -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->l *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->l /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->l %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->l = ~p->l;
                return 1;
        case FILE_LESHORT:
                p->h = (short)((p->hs[1]<<8)|(p->hs[0]));
                if (m->mask)
                        switch (m->mask_op&0x7F) {
                        case FILE_OPAND:
                                p->h &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->h |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->h ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->h += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->h -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->h *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->h /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->h %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->h = ~p->h;
                return 1;
        case FILE_LELONG:
        case FILE_LEDATE:
        case FILE_LELDATE:
                p->l = (int32_t)
                    ((p->hl[3]<<24)|(p->hl[2]<<16)|(p->hl[1]<<8)|(p->hl[0]));
                if (m->mask)
                        switch (m->mask_op&0x7F) {
                        case FILE_OPAND:
                                p->l &= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPOR:
                                p->l |= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPXOR:
                                p->l ^= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPADD:
                                p->l += m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMINUS:
                                p->l -= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMULTIPLY:
                                p->l *= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPDIVIDE:
                                p->l /= m->mask;
                                /*@innerbreak@*/ break;
                        case FILE_OPMODULO:
                                p->l %= m->mask;
                                /*@innerbreak@*/ break;
                        }
                if (m->mask_op & FILE_OPINVERSE)
                        p->l = ~p->l;
                return 1;
        case FILE_REGEX:
        case FILE_SEARCH:
                return 1;
        default:
                file_error(ms, 0, "invalid type %d in mconvert()", m->type);
                return 0;
        }
}


private void
mdebug(uint32_t offset, const char *str, size_t len)
{
        (void) fprintf(stderr, "mget @%d: ", offset);
        file_showstr(stderr, str, len);
        (void) fputc('\n', stderr);
        (void) fputc('\n', stderr);
}

private int
mcopy(struct magic_set *ms, union VALUETYPE *p, int type, int indir,
    const unsigned char *s, size_t offset, size_t nbytes)
{
        if (type == FILE_REGEX && indir == 0) {
                /*
                 * offset is interpreted as last line to search,
                 * (starting at 1), not as bytes-from start-of-file
                 */
                char *b, *c, *last = NULL;
                if ((p->search.buf = strdup((const char *)s)) == NULL) {
                        file_oomem(ms);
                        return -1;
                }
                for (b = p->search.buf; offset && 
                    ((b = strchr(c = b, '\n')) != NULL || (b = strchr(c, '\r')) != NULL);
                    offset--, b++) {
                        last = b;
                        if (b[0] == '\r' && b[1] == '\n') b++;
                }
                if (last != NULL)
                        *last = '\0';
                p->search.buflen = last - p->search.buf;
                return 0;
        }

        if (indir == 0 && (type == FILE_BESTRING16 || type == FILE_LESTRING16))
        {
                const unsigned char *src = s + offset;
                const unsigned char *esrc = s + nbytes;
                char *dst = p->s, *edst = &p->s[sizeof(p->s) - 1];

                if (type == FILE_BESTRING16)
                        src++;

                for (;src < esrc; src++, dst++) {
                        if (dst < edst)
                                *dst = *src++;
                        else
                                break;
                        if (*dst == '\0')
                                *dst = ' ';
                }
                *edst = '\0';
                return 0;
        }

        if (offset >= nbytes) {
                (void)memset(p, '\0', sizeof(*p));
                return 0;
        }
        if (nbytes - offset < sizeof(*p))
                nbytes = nbytes - offset;
        else
                nbytes = sizeof(*p);

        (void)memcpy(p, s + offset, nbytes);

        /*
         * the usefulness of padding with zeroes eludes me, it
         * might even cause problems
         */
        if (nbytes < sizeof(*p))
                (void)memset(((char *)(void *)p) + nbytes, '\0',
                    sizeof(*p) - nbytes);
        return 0;
}

private int
mget(struct magic_set *ms, union VALUETYPE *p, const unsigned char *s,
    struct magic *m, size_t nbytes, unsigned int cont_level)
{
        uint32_t offset = m->offset;

        if (mcopy(ms, p, m->type, m->flag & INDIR, s, offset, nbytes) == -1)
                return -1;

        if ((ms->flags & MAGIC_DEBUG) != 0) {
                mdebug(offset, (char *)(void *)p, sizeof(union VALUETYPE));
                file_mdump(m);
        }

        if (m->flag & INDIR) {
                int off = m->in_offset;
                if (m->in_op & FILE_OPINDIRECT) {
                        const union VALUETYPE *q =
                            ((const void *)(s + offset + off));
                        switch (m->in_type) {
                        case FILE_BYTE:
                                off = q->b;
                                break;
                        case FILE_SHORT:
                                off = q->h;
                                break;
                        case FILE_BESHORT:
                                off = (short)((q->hs[0]<<8)|(q->hs[1]));
                                break;
                        case FILE_LESHORT:
                                off = (short)((q->hs[1]<<8)|(q->hs[0]));
                                break;
                        case FILE_LONG:
                                off = q->l;
                                break;
                        case FILE_BELONG:
                                off = (int32_t)((q->hl[0]<<24)|(q->hl[1]<<16)|
                                                 (q->hl[2]<<8)|(q->hl[3]));
                                break;
                        case FILE_LELONG:
                                off = (int32_t)((q->hl[3]<<24)|(q->hl[2]<<16)|
                                                 (q->hl[1]<<8)|(q->hl[0]));
                                break;
                        }
                }
                switch (m->in_type) {
                case FILE_BYTE:
                        if (nbytes < (offset + 1)) return 0;
                        if (off) {
                                switch (m->in_op & 0x3F) {
                                case FILE_OPAND:
                                        offset = p->b & off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = p->b | off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = p->b ^ off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = p->b + off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = p->b - off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = p->b * off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = p->b / off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = p->b % off;
                                        /*@innerbreak@*/ break;
                                }
                        } else
                                offset = p->b;
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_BESHORT:
                        if (nbytes < (offset + 2))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) &
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) |
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) ^
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) +
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) -
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) *
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) /
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = (short)((p->hs[0]<<8)|
                                                         (p->hs[1])) %
                                                 off;
                                        /*@innerbreak@*/ break;
                                }
                        } else
                                offset = (short)((p->hs[0]<<8)|
                                                 (p->hs[1]));
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_LESHORT:
                        if (nbytes < (offset + 2))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) &
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) |
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) ^
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) +
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) -
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) *
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) /
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = (short)((p->hs[1]<<8)|
                                                         (p->hs[0])) %
                                                 off;
                                        /*@innerbreak@*/ break;
                                }
                        } else
                                offset = (short)((p->hs[1]<<8)|
                                                 (p->hs[0]));
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_SHORT:
                        if (nbytes < (offset + 2))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = p->h & off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = p->h | off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = p->h ^ off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = p->h + off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = p->h - off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = p->h * off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = p->h / off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = p->h % off;
                                        /*@innerbreak@*/ break;
                                }
                        }
                        else
                                offset = p->h;
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_BELONG:
                        if (nbytes < (offset + 4))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) &
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) |
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) ^
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) +
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) -
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) *
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) /
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = (int32_t)((p->hl[0]<<24)|
                                                         (p->hl[1]<<16)|
                                                         (p->hl[2]<<8)|
                                                         (p->hl[3])) %
                                                 off;
                                        /*@innerbreak@*/ break;
                                }
                        } else
                                offset = (int32_t)((p->hl[0]<<24)|
                                                 (p->hl[1]<<16)|
                                                 (p->hl[2]<<8)|
                                                 (p->hl[3]));
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_LELONG:
                        if (nbytes < (offset + 4))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) &
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) |
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) ^
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) +
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) -
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) *
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) /
                                                 off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = (int32_t)((p->hl[3]<<24)|
                                                         (p->hl[2]<<16)|
                                                         (p->hl[1]<<8)|
                                                         (p->hl[0])) %
                                                 off;
                                        /*@innerbreak@*/ break;
                                }
                        } else
                                offset = (int32_t)((p->hl[3]<<24)|
                                                 (p->hl[2]<<16)|
                                                 (p->hl[1]<<8)|
                                                 (p->hl[0]));
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                case FILE_LONG:
                        if (nbytes < (offset + 4))
                                return 0;
                        if (off) {
                                switch (m->in_op & 0x7F) {
                                case FILE_OPAND:
                                        offset = p->l & off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPOR:
                                        offset = p->l | off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPXOR:
                                        offset = p->l ^ off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPADD:
                                        offset = p->l + off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMINUS:
                                        offset = p->l - off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMULTIPLY:
                                        offset = p->l * off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPDIVIDE:
                                        offset = p->l / off;
                                        /*@innerbreak@*/ break;
                                case FILE_OPMODULO:
                                        offset = p->l % off;
                                        /*@innerbreak@*/ break;
                        /*      case TOOMANYSWITCHBLOCKS:
                         *              ugh = p->eye % m->strain;
                         *              rub;
                         *      case BEER:
                         *              off = p->tab & m->in_gest;
                         *              sleep;
                         */
                                }
                        } else
                                offset = p->l;
                        if (m->in_op & FILE_OPINVERSE)
                                offset = ~offset;
                        break;
                }

                if (m->flag & INDIROFFADD) offset += ms->c.off[cont_level-1];
                if (mcopy(ms, p, m->type, 0, s, offset, nbytes) == -1)
                        return -1;
                m->offset = offset;

                if ((ms->flags & MAGIC_DEBUG) != 0) {
                        mdebug(offset, (char *)(void *)p,
                            sizeof(union VALUETYPE));
                        file_mdump(m);
                }
        }

        /* Verify we have enough data to match magic type */
        switch (m->type) {
                case FILE_BYTE:
                        if (nbytes < (offset + 1)) /* should alway be true */
                                return 0;
                        break;

                case FILE_SHORT:
                case FILE_BESHORT:
                case FILE_LESHORT:
                        if (nbytes < (offset + 2))
                                return 0;
                        break;

                case FILE_LONG:
                case FILE_BELONG:
                case FILE_LELONG:
                case FILE_DATE:
                case FILE_BEDATE:
                case FILE_LEDATE:
                case FILE_LDATE:
                case FILE_BELDATE:
                case FILE_LELDATE:
                        if (nbytes < (offset + 4))
                                return 0;
                        break;

                case FILE_STRING:
                case FILE_PSTRING:
                case FILE_SEARCH:
                        if (nbytes < (offset + m->vallen))
                                return 0;
                        break;
                default: break;
        }

        if (m->type == FILE_SEARCH) {
                size_t mlen = m->mask + m->vallen;
                size_t flen = nbytes - offset;
                if (flen < mlen)
                        mlen = flen;
                p->search.buflen = mlen;
                p->search.buf = malloc(mlen + 1);
                if (p->search.buf == NULL) {
                        file_error(ms, errno, "Cannot allocate search buffer");
                        return 0;
                }
                (void)memcpy(p->search.buf, s + offset, mlen);
                p->search.buf[mlen] = '\0';
        }
        if (!mconvert(ms, p, m))
                return 0;
        return 1;
}

private int
mymcheck(struct magic_set *ms, union VALUETYPE *p, struct magic *m)
{
        uint32_t l = m->value.l;
        uint32_t v;
        int matched;

        if ( (m->value.s[0] == 'x') && (m->value.s[1] == '\0') ) {
                return 1;
        }


        switch (m->type) {
        case FILE_BYTE:
                v = p->b;
                break;

        case FILE_SHORT:
        case FILE_BESHORT:
        case FILE_LESHORT:
                v = p->h;
                break;

        case FILE_LONG:
        case FILE_BELONG:
        case FILE_LELONG:
        case FILE_DATE:
        case FILE_BEDATE:
        case FILE_LEDATE:
        case FILE_LDATE:
        case FILE_BELDATE:
        case FILE_LELDATE:
                v = p->l;
                break;

        case FILE_STRING:
        case FILE_BESTRING16:
        case FILE_LESTRING16:
        case FILE_PSTRING:
        {
                /*
                 * 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.
                 */
                unsigned char *a = (unsigned char*)m->value.s;
                unsigned char *b = (unsigned char*)p->s;
                int len = m->vallen;
                l = 0;
                v = 0;
                if (0L == m->mask) { /* normal string: do it fast */
                        while (--len >= 0)
                                if ((v = *b++ - *a++) != '\0')
                                        /*@loopbreak@*/ break; 
                } else { /* combine the others */
                        while (--len >= 0) {
                                if ((m->mask & STRING_IGNORE_LOWERCASE) &&
                                    islower(*a)) {
                                        if ((v = tolower(*b++) - *a++) != '\0')
                                                /*@loopbreak@*/ break;
                                } else if ((m->mask & STRING_COMPACT_BLANK) && 
                                    isspace(*a)) { 
                                        a++;
                                        if (isspace(*b++)) {
                                                while (isspace(*b))
                                                        b++;
                                        } else {
                                                v = 1;
                                                /*@loopbreak@*/ break;
                                        }
                                } else if (isspace(*a) &&
                                    (m->mask & STRING_COMPACT_OPTIONAL_BLANK)) {
                                        a++;
                                        while (isspace(*b))
                                                b++;
                                } else {
                                        if ((v = *b++ - *a++) != '\0')
                                                /*@loopbreak@*/ break;
                                }
                        }
                }
                break;
        }
        case FILE_REGEX:
        {
                int rc;
                regex_t rx;
                char errmsg[512];

                if (p->search.buf == NULL)
                        return 0;

                rc = regcomp(&rx, m->value.s,
                    REG_EXTENDED|REG_NOSUB|REG_NEWLINE|
                    ((m->mask & STRING_IGNORE_LOWERCASE) ? REG_ICASE : 0));
                if (rc) {
                        free(p->search.buf);
                        p->search.buf = NULL;
                        (void) regerror(rc, &rx, errmsg, sizeof(errmsg));
                        file_error(ms, 0, "regex error %d, (%s)", rc, errmsg);
                        return -1;
                } else {
/*@i@*/                 rc = regexec(&rx, p->search.buf, 0, 0, 0);
/*@i@*/                 regfree(&rx);
                        free(p->search.buf);
                        p->search.buf = NULL;
                        return !rc;
                }
        }
        case FILE_SEARCH:
        {
                /*
                 * search for a string in a certain range
                 */
                unsigned char *a = (unsigned char*)m->value.s;
                unsigned char *b = (unsigned char*)p->search.buf;
                size_t len, slen = m->vallen;
                size_t range = 0;
                if (slen > sizeof(m->value.s))
                        slen = sizeof(m->value.s);
                l = 0;
                v = 0;
                if (b == NULL)
                        return 0;
                len = slen;
                while (++range <= m->mask) {
                        while (len-- > 0 && (v = *b++ - *a++) == 0)
                                /*@innercontinue@*/ continue;
                        if (!v) {
                                m->offset += range - 1;
                                /*@loopbreak@*/ break;
                        }
                        if (range + slen >= p->search.buflen)
                                /*@loopbreak@*/ break;
                        len = slen;
                        a = (unsigned char*)m->value.s;
                        b = (unsigned char*)p->search.buf + range;
                }
                free(p->search.buf);
                p->search.buf = NULL;
                break;
        }
        default:
                file_error(ms, 0, "invalid type %d in mcheck()", m->type);
                return -1;
        }

        if (m->type != FILE_STRING && m->type != FILE_PSTRING)
                v = file_signextend(ms, m, v);

        switch (m->reln) {
        case 'x':
                if ((ms->flags & MAGIC_DEBUG) != 0)
                        (void) fprintf(stderr, "%u == *any* = 1\n", v);
                matched = 1;
                break;

        case '!':
                matched = v != l;
                if ((ms->flags & MAGIC_DEBUG) != 0)
                        (void) fprintf(stderr, "%u != %u = %d\n",
                                       v, l, matched);
                break;

        case '=':
                matched = v == l;
                if ((ms->flags & MAGIC_DEBUG) != 0)
                        (void) fprintf(stderr, "%u == %u = %d\n",
                                       v, l, matched);
                break;

        case '>':
                if (m->flag & UNSIGNED) {
                        matched = v > l;
                        if ((ms->flags & MAGIC_DEBUG) != 0)
                                (void) fprintf(stderr, "%u > %u = %d\n",
                                               v, l, matched);
                }
                else {
                        matched = (int32_t) v > (int32_t) l;
                        if ((ms->flags & MAGIC_DEBUG) != 0)
                                (void) fprintf(stderr, "%d > %d = %d\n",
                                               v, l, matched);
                }
                break;

        case '<':
                if (m->flag & UNSIGNED) {
                        matched = v < l;
                        if ((ms->flags & MAGIC_DEBUG) != 0)
                                (void) fprintf(stderr, "%u < %u = %d\n",
                                               v, l, matched);
                }
                else {
                        matched = (int32_t) v < (int32_t) l;
                        if ((ms->flags & MAGIC_DEBUG) != 0)
                                (void) fprintf(stderr, "%d < %d = %d\n",
                                               v, l, matched);
                }
                break;

        case '&':
                matched = (v & l) == l;
                if ((ms->flags & MAGIC_DEBUG) != 0)
                        (void) fprintf(stderr, "((%x & %x) == %x) = %d\n",
                                       v, l, l, matched);
                break;

        case '^':
                matched = (v & l) != l;
                if ((ms->flags & MAGIC_DEBUG) != 0)
                        (void) fprintf(stderr, "((%x & %x) != %x) = %d\n",
                                       v, l, l, matched);
                break;

        default:
                matched = 0;
                file_error(ms, 0, "cannot happen: invalid relation `%c'",
                    m->reln);
                return -1;
        }

        return matched;
}
/*@=usereleased@*/
/*@=uniondef@*/
/*@=sizeoftype@*/
/*@=evalorder@*/
/*@=compdef@*/ 

---