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freebsd-dev/contrib/file/apprentice.c
David E. O'Brien 88a5e5ac7b Virgin import of Christos Zoulas's FILE 4.17.
2006-06-19 07:52:15 +00:00

1411 lines
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/*
* 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.
*/
/*
* apprentice - make one pass through /etc/magic, learning its secrets.
*/
#include "file.h"
#include "magic.h"
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/param.h>
#ifdef QUICK
#include <sys/mman.h>
#endif
#ifndef lint
FILE_RCSID("@(#)$Id: apprentice.c,v 1.87 2006/03/02 22:08:57 christos Exp $")
#endif /* lint */
#define EATAB {while (isascii((unsigned char) *l) && \
isspace((unsigned char) *l)) ++l;}
#define LOWCASE(l) (isupper((unsigned char) (l)) ? \
tolower((unsigned char) (l)) : (l))
/*
* Work around a bug in headers on Digital Unix.
* At least confirmed for: OSF1 V4.0 878
*/
#if defined(__osf__) && defined(__DECC)
#ifdef MAP_FAILED
#undef MAP_FAILED
#endif
#endif
#ifndef MAP_FAILED
#define MAP_FAILED (void *) -1
#endif
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
#ifndef MAXPATHLEN
#define MAXPATHLEN 1024
#endif
#define IS_PLAINSTRING(t) ((t) == FILE_STRING || (t) == FILE_PSTRING || \
(t) == FILE_BESTRING16 || (t) == FILE_LESTRING16)
#define IS_STRING(t) (IS_PLAINSTRING(t) || (t) == FILE_REGEX || \
(t) == FILE_SEARCH)
struct magic_entry {
struct magic *mp;
uint32_t cont_count;
uint32_t max_count;
};
private int getvalue(struct magic_set *ms, struct magic *, const char **);
private int hextoint(int);
private const char *getstr(struct magic_set *, const char *, char *, int,
int *);
private int parse(struct magic_set *, struct magic_entry **, uint32_t *,
const char *, int);
private void eatsize(const char **);
private int apprentice_1(struct magic_set *, const char *, int, struct mlist *);
private size_t apprentice_magic_strength(const struct magic *);
private int apprentice_sort(const void *, const void *);
private int apprentice_file(struct magic_set *, struct magic **, uint32_t *,
const char *, int);
private void byteswap(struct magic *, uint32_t);
private void bs1(struct magic *);
private uint16_t swap2(uint16_t);
private uint32_t swap4(uint32_t);
private char *mkdbname(const char *, char *, size_t, int);
private int apprentice_map(struct magic_set *, struct magic **, uint32_t *,
const char *);
private int apprentice_compile(struct magic_set *, struct magic **, uint32_t *,
const char *);
private int check_format(struct magic_set *, struct magic *);
private size_t maxmagic = 0;
private size_t magicsize = sizeof(struct magic);
#ifdef COMPILE_ONLY
int main(int, char *[]);
int
main(int argc, char *argv[])
{
int ret;
struct magic_set *ms;
char *progname;
if ((progname = strrchr(argv[0], '/')) != NULL)
progname++;
else
progname = argv[0];
if (argc != 2) {
(void)fprintf(stderr, "Usage: %s file\n", progname);
return 1;
}
if ((ms = magic_open(MAGIC_CHECK)) == NULL) {
(void)fprintf(stderr, "%s: %s\n", progname, strerror(errno));
return 1;
}
ret = magic_compile(ms, argv[1]) == -1 ? 1 : 0;
if (ret == 1)
(void)fprintf(stderr, "%s: %s\n", progname, magic_error(ms));
magic_close(ms);
return ret;
}
#endif /* COMPILE_ONLY */
/*
* Handle one file.
*/
private int
apprentice_1(struct magic_set *ms, const char *fn, int action,
struct mlist *mlist)
{
struct magic *magic = NULL;
uint32_t nmagic = 0;
struct mlist *ml;
int rv = -1;
int mapped;
if (magicsize != FILE_MAGICSIZE) {
file_error(ms, 0, "magic element size %lu != %lu",
(unsigned long)sizeof(*magic),
(unsigned long)FILE_MAGICSIZE);
return -1;
}
if (action == FILE_COMPILE) {
rv = apprentice_file(ms, &magic, &nmagic, fn, action);
if (rv != 0)
return -1;
rv = apprentice_compile(ms, &magic, &nmagic, fn);
free(magic);
return rv;
}
#ifndef COMPILE_ONLY
if ((rv = apprentice_map(ms, &magic, &nmagic, fn)) == -1) {
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms, "using regular magic file `%s'", fn);
rv = apprentice_file(ms, &magic, &nmagic, fn, action);
if (rv != 0)
return -1;
mapped = 0;
}
if (rv == -1)
return rv;
mapped = rv;
if (magic == NULL || nmagic == 0) {
file_delmagic(magic, mapped, nmagic);
return -1;
}
if ((ml = malloc(sizeof(*ml))) == NULL) {
file_delmagic(magic, mapped, nmagic);
file_oomem(ms);
return -1;
}
ml->magic = magic;
ml->nmagic = nmagic;
ml->mapped = mapped;
mlist->prev->next = ml;
ml->prev = mlist->prev;
ml->next = mlist;
mlist->prev = ml;
return 0;
#endif /* COMPILE_ONLY */
}
protected void
file_delmagic(struct magic *p, int type, size_t entries)
{
if (p == NULL)
return;
switch (type) {
case 2:
p--;
(void)munmap((void *)p, sizeof(*p) * (entries + 1));
break;
case 1:
p--;
/*FALLTHROUGH*/
case 0:
free(p);
break;
default:
abort();
}
}
/* const char *fn: list of magic files */
protected struct mlist *
file_apprentice(struct magic_set *ms, const char *fn, int action)
{
char *p, *mfn, *afn = NULL;
int file_err, errs = -1;
struct mlist *mlist;
if (fn == NULL)
fn = getenv("MAGIC");
if (fn == NULL)
fn = MAGIC;
if ((fn = mfn = strdup(fn)) == NULL) {
file_oomem(ms);
return NULL;
}
if ((mlist = malloc(sizeof(*mlist))) == NULL) {
free(mfn);
file_oomem(ms);
return NULL;
}
mlist->next = mlist->prev = mlist;
while (fn) {
p = strchr(fn, PATHSEP);
if (p)
*p++ = '\0';
if (*fn == '\0')
break;
if (ms->flags & MAGIC_MIME) {
if ((afn = malloc(strlen(fn) + 5 + 1)) == NULL) {
free(mfn);
free(mlist);
file_oomem(ms);
return NULL;
}
(void)strcpy(afn, fn);
(void)strcat(afn, ".mime");
fn = afn;
}
file_err = apprentice_1(ms, fn, action, mlist);
if (file_err > errs)
errs = file_err;
if (afn) {
free(afn);
afn = NULL;
}
fn = p;
}
if (errs == -1) {
free(mfn);
free(mlist);
mlist = NULL;
file_error(ms, 0, "could not find any magic files!");
return NULL;
}
free(mfn);
return mlist;
}
private size_t
apprentice_magic_strength(const struct magic *m)
{
switch (m->type) {
case FILE_BYTE:
return 1;
case FILE_SHORT:
case FILE_LESHORT:
case FILE_BESHORT:
return 2;
case FILE_LONG:
case FILE_LELONG:
case FILE_BELONG:
case FILE_MELONG:
return 4;
case FILE_PSTRING:
case FILE_STRING:
case FILE_REGEX:
case FILE_BESTRING16:
case FILE_LESTRING16:
case FILE_SEARCH:
return m->vallen;
case FILE_DATE:
case FILE_LEDATE:
case FILE_BEDATE:
case FILE_MEDATE:
return 4;
case FILE_LDATE:
case FILE_LELDATE:
case FILE_BELDATE:
case FILE_MELDATE:
return 8;
default:
return 0;
}
}
private int
apprentice_sort(const void *a, const void *b)
{
const struct magic_entry *ma = a;
const struct magic_entry *mb = b;
size_t sa = apprentice_magic_strength(ma->mp);
size_t sb = apprentice_magic_strength(mb->mp);
if (sa == sb)
return 0;
else if (sa > sb)
return -1;
else
return 1;
}
/*
* parse from a file
* const char *fn: name of magic file
*/
private int
apprentice_file(struct magic_set *ms, struct magic **magicp, uint32_t *nmagicp,
const char *fn, int action)
{
private const char hdr[] =
"cont\toffset\ttype\topcode\tmask\tvalue\tdesc";
FILE *f;
char line[BUFSIZ+1];
int errs = 0;
struct magic_entry *marray;
uint32_t marraycount, i, mentrycount;
f = fopen(ms->file = fn, "r");
if (f == NULL) {
if (errno != ENOENT)
file_error(ms, errno, "cannot read magic file `%s'",
fn);
return -1;
}
maxmagic = MAXMAGIS;
if ((marray = malloc(maxmagic * sizeof(*marray))) == NULL) {
(void)fclose(f);
file_oomem(ms);
return -1;
}
marraycount = 0;
/* print silly verbose header for USG compat. */
if (action == FILE_CHECK)
(void)fprintf(stderr, "%s\n", hdr);
/* parse it */
for (ms->line = 1; fgets(line, BUFSIZ, f) != NULL; ms->line++) {
size_t len;
if (line[0] == '#') /* comment, do not parse */
continue;
len = strlen(line);
if (len < 2) /* null line, garbage, etc */
continue;
if (line[len - 1] == '\n')
line[len - 1] = '\0'; /* delete newline */
if (parse(ms, &marray, &marraycount, line, action) != 0)
errs++;
}
(void)fclose(f);
if (errs)
goto out;
#ifndef NOORDER
qsort(marray, marraycount, sizeof(*marray), apprentice_sort);
#endif
for (i = 0, mentrycount = 0; i < marraycount; i++)
mentrycount += marray[i].cont_count;
if ((*magicp = malloc(sizeof(**magicp) * mentrycount)) == NULL) {
file_oomem(ms);
errs++;
goto out;
}
mentrycount = 0;
for (i = 0; i < marraycount; i++) {
(void)memcpy(*magicp + mentrycount, marray[i].mp,
marray[i].cont_count * sizeof(**magicp));
mentrycount += marray[i].cont_count;
}
out:
for (i = 0; i < marraycount; i++)
free(marray[i].mp);
free(marray);
if (errs) {
*magicp = NULL;
*nmagicp = 0;
return errs;
} else {
*nmagicp = mentrycount;
return 0;
}
}
/*
* extend the sign bit if the comparison is to be signed
*/
protected uint32_t
file_signextend(struct magic_set *ms, struct magic *m, uint32_t v)
{
if (!(m->flag & UNSIGNED))
switch(m->type) {
/*
* Do not remove the casts below. They are
* vital. When later compared with the data,
* the sign extension must have happened.
*/
case FILE_BYTE:
v = (char) v;
break;
case FILE_SHORT:
case FILE_BESHORT:
case FILE_LESHORT:
v = (short) v;
break;
case FILE_DATE:
case FILE_BEDATE:
case FILE_LEDATE:
case FILE_MEDATE:
case FILE_LDATE:
case FILE_BELDATE:
case FILE_LELDATE:
case FILE_MELDATE:
case FILE_LONG:
case FILE_BELONG:
case FILE_LELONG:
case FILE_MELONG:
v = (int32_t) v;
break;
case FILE_STRING:
case FILE_PSTRING:
case FILE_BESTRING16:
case FILE_LESTRING16:
case FILE_REGEX:
case FILE_SEARCH:
break;
default:
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms, "cannot happen: m->type=%d\n",
m->type);
return ~0U;
}
return v;
}
/*
* parse one line from magic file, put into magic[index++] if valid
*/
private int
parse(struct magic_set *ms, struct magic_entry **mentryp, uint32_t *nmentryp,
const char *line, int action)
{
int i = 0;
struct magic_entry *me;
struct magic *m;
const char *l = line;
char *t;
private const char *fops = FILE_OPS;
uint32_t val;
uint32_t cont_level, cont_count;
cont_level = 0;
while (*l == '>') {
++l; /* step over */
cont_level++;
}
#define ALLOC_CHUNK (size_t)10
#define ALLOC_INCR (size_t)200
if (cont_level != 0) {
if (*nmentryp == 0) {
file_error(ms, 0, "No current entry for continuation");
return -1;
}
me = &(*mentryp)[*nmentryp - 1];
if (me->cont_count == me->max_count) {
struct magic *nm;
size_t cnt = me->max_count + ALLOC_CHUNK;
if ((nm = realloc(me->mp, sizeof(*nm) * cnt)) == NULL) {
file_oomem(ms);
return -1;
}
me->mp = m = nm;
me->max_count = cnt;
}
m = &me->mp[me->cont_count++];
memset(m, 0, sizeof(*m));
m->cont_level = cont_level;
} else {
if (*nmentryp == maxmagic) {
struct magic_entry *mp;
maxmagic += ALLOC_INCR;
if ((mp = realloc(*mentryp, sizeof(*mp) * maxmagic)) ==
NULL) {
file_oomem(ms);
return -1;
}
(void)memset(&mp[*nmentryp], 0, sizeof(*mp) *
ALLOC_INCR);
*mentryp = mp;
}
me = &(*mentryp)[*nmentryp];
if (me->mp == NULL) {
if ((m = malloc(sizeof(*m) * ALLOC_CHUNK)) == NULL) {
file_oomem(ms);
return -1;
}
me->mp = m;
me->max_count = ALLOC_CHUNK;
} else
m = me->mp;
memset(m, 0, sizeof(*m));
m->cont_level = 0;
me->cont_count = 1;
}
if (m->cont_level != 0 && *l == '&') {
++l; /* step over */
m->flag |= OFFADD;
}
if (m->cont_level != 0 && *l == '(') {
++l; /* step over */
m->flag |= INDIR;
if (m->flag & OFFADD)
m->flag = (m->flag & ~OFFADD) | INDIROFFADD;
}
if (m->cont_level != 0 && *l == '&') {
++l; /* step over */
m->flag |= OFFADD;
}
/* get offset, then skip over it */
m->offset = (uint32_t)strtoul(l, &t, 0);
if (l == t)
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms, "offset `%s' invalid", l);
l = t;
if (m->flag & INDIR) {
m->in_type = FILE_LONG;
m->in_offset = 0;
/*
* read [.lbs][+-]nnnnn)
*/
if (*l == '.') {
l++;
switch (*l) {
case 'l':
m->in_type = FILE_LELONG;
break;
case 'L':
m->in_type = FILE_BELONG;
break;
case 'm':
m->in_type = FILE_MELONG;
break;
case 'h':
case 's':
m->in_type = FILE_LESHORT;
break;
case 'H':
case 'S':
m->in_type = FILE_BESHORT;
break;
case 'c':
case 'b':
case 'C':
case 'B':
m->in_type = FILE_BYTE;
break;
default:
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms,
"indirect offset type `%c' invalid",
*l);
break;
}
l++;
}
if (*l == '~') {
m->in_op |= FILE_OPINVERSE;
l++;
}
switch (*l) {
case '&':
m->in_op |= FILE_OPAND;
l++;
break;
case '|':
m->in_op |= FILE_OPOR;
l++;
break;
case '^':
m->in_op |= FILE_OPXOR;
l++;
break;
case '+':
m->in_op |= FILE_OPADD;
l++;
break;
case '-':
m->in_op |= FILE_OPMINUS;
l++;
break;
case '*':
m->in_op |= FILE_OPMULTIPLY;
l++;
break;
case '/':
m->in_op |= FILE_OPDIVIDE;
l++;
break;
case '%':
m->in_op |= FILE_OPMODULO;
l++;
break;
}
if (*l == '(') {
m->in_op |= FILE_OPINDIRECT;
l++;
}
if (isdigit((unsigned char)*l) || *l == '-') {
m->in_offset = (int32_t)strtol(l, &t, 0);
l = t;
}
if (*l++ != ')' ||
((m->in_op & FILE_OPINDIRECT) && *l++ != ')'))
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms,
"missing ')' in indirect offset");
}
while (isascii((unsigned char)*l) && isdigit((unsigned char)*l))
++l;
EATAB;
#define NBYTE 4
#define NSHORT 5
#define NLONG 4
#define NSTRING 6
#define NDATE 4
#define NBESHORT 7
#define NBELONG 6
#define NBEDATE 6
#define NLESHORT 7
#define NLELONG 6
#define NMELONG 6
#define NLEDATE 6
#define NMEDATE 6
#define NPSTRING 7
#define NLDATE 5
#define NBELDATE 7
#define NLELDATE 7
#define NMELDATE 7
#define NREGEX 5
#define NBESTRING16 10
#define NLESTRING16 10
#define NSEARCH 6
if (*l == 'u') {
++l;
m->flag |= UNSIGNED;
}
/* get type, skip it */
if (strncmp(l, "char", NBYTE)==0) { /* HP/UX compat */
m->type = FILE_BYTE;
l += NBYTE;
} else if (strncmp(l, "byte", NBYTE)==0) {
m->type = FILE_BYTE;
l += NBYTE;
} else if (strncmp(l, "short", NSHORT)==0) {
m->type = FILE_SHORT;
l += NSHORT;
} else if (strncmp(l, "long", NLONG)==0) {
m->type = FILE_LONG;
l += NLONG;
} else if (strncmp(l, "string", NSTRING)==0) {
m->type = FILE_STRING;
l += NSTRING;
} else if (strncmp(l, "date", NDATE)==0) {
m->type = FILE_DATE;
l += NDATE;
} else if (strncmp(l, "beshort", NBESHORT)==0) {
m->type = FILE_BESHORT;
l += NBESHORT;
} else if (strncmp(l, "belong", NBELONG)==0) {
m->type = FILE_BELONG;
l += NBELONG;
} else if (strncmp(l, "bedate", NBEDATE)==0) {
m->type = FILE_BEDATE;
l += NBEDATE;
} else if (strncmp(l, "leshort", NLESHORT)==0) {
m->type = FILE_LESHORT;
l += NLESHORT;
} else if (strncmp(l, "lelong", NLELONG)==0) {
m->type = FILE_LELONG;
l += NLELONG;
} else if (strncmp(l, "melong", NMELONG)==0) {
m->type = FILE_MELONG;
l += NMELONG;
} else if (strncmp(l, "ledate", NLEDATE)==0) {
m->type = FILE_LEDATE;
l += NLEDATE;
} else if (strncmp(l, "medate", NMEDATE)==0) {
m->type = FILE_MEDATE;
l += NMEDATE;
} else if (strncmp(l, "pstring", NPSTRING)==0) {
m->type = FILE_PSTRING;
l += NPSTRING;
} else if (strncmp(l, "ldate", NLDATE)==0) {
m->type = FILE_LDATE;
l += NLDATE;
} else if (strncmp(l, "beldate", NBELDATE)==0) {
m->type = FILE_BELDATE;
l += NBELDATE;
} else if (strncmp(l, "leldate", NLELDATE)==0) {
m->type = FILE_LELDATE;
l += NLELDATE;
} else if (strncmp(l, "meldate", NMELDATE)==0) {
m->type = FILE_MELDATE;
l += NMELDATE;
} else if (strncmp(l, "regex", NREGEX)==0) {
m->type = FILE_REGEX;
l += NREGEX;
} else if (strncmp(l, "bestring16", NBESTRING16)==0) {
m->type = FILE_BESTRING16;
l += NBESTRING16;
} else if (strncmp(l, "lestring16", NLESTRING16)==0) {
m->type = FILE_LESTRING16;
l += NLESTRING16;
} else if (strncmp(l, "search", NSEARCH)==0) {
m->type = FILE_SEARCH;
l += NSEARCH;
} else {
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms, "type `%s' invalid", l);
return -1;
}
/* New-style anding: "0 byte&0x80 =0x80 dynamically linked" */
/* New and improved: ~ & | ^ + - * / % -- exciting, isn't it? */
if (*l == '~') {
if (!IS_STRING(m->type))
m->mask_op |= FILE_OPINVERSE;
++l;
}
if ((t = strchr(fops, *l)) != NULL) {
uint32_t op = (uint32_t)(t - fops);
if (op != FILE_OPDIVIDE || !IS_PLAINSTRING(m->type)) {
++l;
m->mask_op |= op;
val = (uint32_t)strtoul(l, &t, 0);
l = t;
m->mask = file_signextend(ms, m, val);
eatsize(&l);
} else {
m->mask = 0L;
while (!isspace((unsigned char)*++l)) {
switch (*l) {
case CHAR_IGNORE_LOWERCASE:
m->mask |= STRING_IGNORE_LOWERCASE;
break;
case CHAR_COMPACT_BLANK:
m->mask |= STRING_COMPACT_BLANK;
break;
case CHAR_COMPACT_OPTIONAL_BLANK:
m->mask |=
STRING_COMPACT_OPTIONAL_BLANK;
break;
default:
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms,
"string extension `%c' invalid",
*l);
return -1;
}
}
++l;
}
}
/*
* We used to set mask to all 1's here, instead let's just not do
* anything if mask = 0 (unless you have a better idea)
*/
EATAB;
switch (*l) {
case '>':
case '<':
/* Old-style anding: "0 byte &0x80 dynamically linked" */
case '&':
case '^':
case '=':
m->reln = *l;
++l;
if (*l == '=') {
/* HP compat: ignore &= etc. */
++l;
}
break;
case '!':
m->reln = *l;
++l;
break;
default:
if (*l == 'x' && ((isascii((unsigned char)l[1]) &&
isspace((unsigned char)l[1])) || !l[1])) {
m->reln = *l;
++l;
goto GetDesc; /* Bill The Cat */
}
m->reln = '=';
break;
}
EATAB;
if (getvalue(ms, m, &l))
return -1;
/*
* TODO finish this macro and start using it!
* #define offsetcheck {if (offset > HOWMANY-1)
* magwarn("offset too big"); }
*/
/*
* now get last part - the description
*/
GetDesc:
EATAB;
if (l[0] == '\b') {
++l;
m->nospflag = 1;
} else if ((l[0] == '\\') && (l[1] == 'b')) {
++l;
++l;
m->nospflag = 1;
} else
m->nospflag = 0;
while ((m->desc[i++] = *l++) != '\0' && i < MAXDESC)
/* NULLBODY */;
if (ms->flags & MAGIC_CHECK) {
if (!check_format(ms, m))
return -1;
}
#ifndef COMPILE_ONLY
if (action == FILE_CHECK) {
file_mdump(m);
}
#endif
if (m->cont_level == 0)
++(*nmentryp); /* make room for next */
return 0;
}
/*
* Check that the optional printf format in description matches
* the type of the magic.
*/
private int
check_format(struct magic_set *ms, struct magic *m)
{
static const char *formats[] = { FILE_FORMAT_STRING };
static const char *names[] = { FILE_FORMAT_NAME };
char *ptr;
for (ptr = m->desc; *ptr; ptr++)
if (*ptr == '%')
break;
if (*ptr == '\0') {
/* No format string; ok */
return 1;
}
if (m->type >= sizeof(formats)/sizeof(formats[0])) {
file_magwarn(ms, "Internal error inconsistency between m->type"
" and format strings");
return 0;
}
if (formats[m->type] == NULL) {
file_magwarn(ms, "No format string for `%s' with description "
"`%s'", m->desc, names[m->type]);
return 0;
}
for (; *ptr; ptr++) {
if (*ptr == 'l' || *ptr == 'h') {
/* XXX: we should really fix this one day */
continue;
}
if (islower((unsigned char)*ptr) || *ptr == 'X')
break;
}
if (*ptr == '\0') {
/* Missing format string; bad */
file_magwarn(ms, "Invalid format `%s' for type `%s'",
m->desc, names[m->type]);
return 0;
}
if (strchr(formats[m->type], *ptr) == NULL) {
file_magwarn(ms, "Printf format `%c' is not valid for type `%s'"
" in description `%s'",
*ptr, names[m->type], m->desc);
return 0;
}
return 1;
}
/*
* Read a numeric value from a pointer, into the value union of a magic
* pointer, according to the magic type. Update the string pointer to point
* just after the number read. Return 0 for success, non-zero for failure.
*/
private int
getvalue(struct magic_set *ms, struct magic *m, const char **p)
{
int slen;
switch (m->type) {
case FILE_BESTRING16:
case FILE_LESTRING16:
case FILE_STRING:
case FILE_PSTRING:
case FILE_REGEX:
case FILE_SEARCH:
*p = getstr(ms, *p, m->value.s, sizeof(m->value.s), &slen);
if (*p == NULL) {
if (ms->flags & MAGIC_CHECK)
file_magwarn(ms, "cannot get string from `%s'",
m->value.s);
return -1;
}
m->vallen = slen;
return 0;
default:
if (m->reln != 'x') {
char *ep;
m->value.l = file_signextend(ms, m,
(uint32_t)strtoul(*p, &ep, 0));
*p = ep;
eatsize(p);
}
return 0;
}
}
/*
* Convert a string containing C character escapes. Stop at an unescaped
* space or tab.
* Copy the converted version to "p", returning its length in *slen.
* Return updated scan pointer as function result.
*/
private const char *
getstr(struct magic_set *ms, const char *s, char *p, int plen, int *slen)
{
const char *origs = s;
char *origp = p;
char *pmax = p + plen - 1;
int c;
int val;
while ((c = *s++) != '\0') {
if (isspace((unsigned char) c))
break;
if (p >= pmax) {
file_error(ms, 0, "string too long: `%s'", origs);
return NULL;
}
if(c == '\\') {
switch(c = *s++) {
case '\0':
goto out;
default:
*p++ = (char) c;
break;
case 'n':
*p++ = '\n';
break;
case 'r':
*p++ = '\r';
break;
case 'b':
*p++ = '\b';
break;
case 't':
*p++ = '\t';
break;
case 'f':
*p++ = '\f';
break;
case 'v':
*p++ = '\v';
break;
/* \ and up to 3 octal digits */
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
val = c - '0';
c = *s++; /* try for 2 */
if(c >= '0' && c <= '7') {
val = (val<<3) | (c - '0');
c = *s++; /* try for 3 */
if(c >= '0' && c <= '7')
val = (val<<3) | (c-'0');
else
--s;
}
else
--s;
*p++ = (char)val;
break;
/* \x and up to 2 hex digits */
case 'x':
val = 'x'; /* Default if no digits */
c = hextoint(*s++); /* Get next char */
if (c >= 0) {
val = c;
c = hextoint(*s++);
if (c >= 0)
val = (val << 4) + c;
else
--s;
} else
--s;
*p++ = (char)val;
break;
}
} else
*p++ = (char)c;
}
out:
*p = '\0';
*slen = p - origp;
return s;
}
/* Single hex char to int; -1 if not a hex char. */
private int
hextoint(int c)
{
if (!isascii((unsigned char) c))
return -1;
if (isdigit((unsigned char) c))
return c - '0';
if ((c >= 'a')&&(c <= 'f'))
return c + 10 - 'a';
if (( c>= 'A')&&(c <= 'F'))
return c + 10 - 'A';
return -1;
}
/*
* Print a string containing C character escapes.
*/
protected void
file_showstr(FILE *fp, const char *s, size_t len)
{
char c;
for (;;) {
c = *s++;
if (len == ~0U) {
if (c == '\0')
break;
}
else {
if (len-- == 0)
break;
}
if(c >= 040 && c <= 0176) /* TODO isprint && !iscntrl */
(void) fputc(c, fp);
else {
(void) fputc('\\', fp);
switch (c) {
case '\n':
(void) fputc('n', fp);
break;
case '\r':
(void) fputc('r', fp);
break;
case '\b':
(void) fputc('b', fp);
break;
case '\t':
(void) fputc('t', fp);
break;
case '\f':
(void) fputc('f', fp);
break;
case '\v':
(void) fputc('v', fp);
break;
default:
(void) fprintf(fp, "%.3o", c & 0377);
break;
}
}
}
}
/*
* eatsize(): Eat the size spec from a number [eg. 10UL]
*/
private void
eatsize(const char **p)
{
const char *l = *p;
if (LOWCASE(*l) == 'u')
l++;
switch (LOWCASE(*l)) {
case 'l': /* long */
case 's': /* short */
case 'h': /* short */
case 'b': /* char/byte */
case 'c': /* char/byte */
l++;
/*FALLTHROUGH*/
default:
break;
}
*p = l;
}
/*
* handle a compiled file.
*/
private int
apprentice_map(struct magic_set *ms, struct magic **magicp, uint32_t *nmagicp,
const char *fn)
{
int fd;
struct stat st;
uint32_t *ptr;
uint32_t version;
int needsbyteswap;
char buf[MAXPATHLEN];
char *dbname = mkdbname(fn, buf, sizeof(buf), 0);
void *mm = NULL;
if (dbname == NULL)
return -1;
if ((fd = open(dbname, O_RDONLY|O_BINARY)) == -1)
return -1;
if (fstat(fd, &st) == -1) {
file_error(ms, errno, "cannot stat `%s'", dbname);
goto error;
}
if (st.st_size < 16) {
file_error(ms, 0, "file `%s' is too small", dbname);
goto error;
}
#ifdef QUICK
if ((mm = mmap(0, (size_t)st.st_size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FILE, fd, (off_t)0)) == MAP_FAILED) {
file_error(ms, errno, "cannot map `%s'", dbname);
goto error;
}
#define RET 2
#else
if ((mm = malloc((size_t)st.st_size)) == NULL) {
file_oomem(ms);
goto error;
}
if (read(fd, mm, (size_t)st.st_size) != (size_t)st.st_size) {
file_badread(ms);
goto error;
}
#define RET 1
#endif
*magicp = mm;
(void)close(fd);
fd = -1;
ptr = (uint32_t *)(void *)*magicp;
if (*ptr != MAGICNO) {
if (swap4(*ptr) != MAGICNO) {
file_error(ms, 0, "bad magic in `%s'");
goto error;
}
needsbyteswap = 1;
} else
needsbyteswap = 0;
if (needsbyteswap)
version = swap4(ptr[1]);
else
version = ptr[1];
if (version != VERSIONNO) {
file_error(ms, 0, "version mismatch (%d != %d) in `%s'",
version, VERSIONNO, dbname);
goto error;
}
*nmagicp = (uint32_t)(st.st_size / sizeof(struct magic)) - 1;
(*magicp)++;
if (needsbyteswap)
byteswap(*magicp, *nmagicp);
return RET;
error:
if (fd != -1)
(void)close(fd);
if (mm) {
#ifdef QUICK
(void)munmap((void *)mm, (size_t)st.st_size);
#else
free(mm);
#endif
} else {
*magicp = NULL;
*nmagicp = 0;
}
return -1;
}
private const uint32_t ar[] = {
MAGICNO, VERSIONNO
};
/*
* handle an mmaped file.
*/
private int
apprentice_compile(struct magic_set *ms, struct magic **magicp,
uint32_t *nmagicp, const char *fn)
{
int fd;
char buf[MAXPATHLEN];
char *dbname = mkdbname(fn, buf, sizeof(buf), 1);
if (dbname == NULL)
return -1;
if ((fd = open(dbname, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644)) == -1) {
file_error(ms, errno, "cannot open `%s'", dbname);
return -1;
}
if (write(fd, ar, sizeof(ar)) != (ssize_t)sizeof(ar)) {
file_error(ms, errno, "error writing `%s'", dbname);
return -1;
}
if (lseek(fd, (off_t)sizeof(struct magic), SEEK_SET)
!= sizeof(struct magic)) {
file_error(ms, errno, "error seeking `%s'", dbname);
return -1;
}
if (write(fd, *magicp, (sizeof(struct magic) * *nmagicp))
!= (ssize_t)(sizeof(struct magic) * *nmagicp)) {
file_error(ms, errno, "error writing `%s'", dbname);
return -1;
}
(void)close(fd);
return 0;
}
private const char ext[] = ".mgc";
/*
* make a dbname
*/
private char *
mkdbname(const char *fn, char *buf, size_t bufsiz, int strip)
{
if (strip) {
const char *p;
if ((p = strrchr(fn, '/')) != NULL)
fn = ++p;
}
(void)snprintf(buf, bufsiz, "%s%s", fn, ext);
return buf;
}
/*
* Byteswap an mmap'ed file if needed
*/
private void
byteswap(struct magic *magic, uint32_t nmagic)
{
uint32_t i;
for (i = 0; i < nmagic; i++)
bs1(&magic[i]);
}
/*
* swap a short
*/
private uint16_t
swap2(uint16_t sv)
{
uint16_t rv;
uint8_t *s = (uint8_t *)(void *)&sv;
uint8_t *d = (uint8_t *)(void *)&rv;
d[0] = s[1];
d[1] = s[0];
return rv;
}
/*
* swap an int
*/
private uint32_t
swap4(uint32_t sv)
{
uint32_t rv;
uint8_t *s = (uint8_t *)(void *)&sv;
uint8_t *d = (uint8_t *)(void *)&rv;
d[0] = s[3];
d[1] = s[2];
d[2] = s[1];
d[3] = s[0];
return rv;
}
/*
* byteswap a single magic entry
*/
private void
bs1(struct magic *m)
{
m->cont_level = swap2(m->cont_level);
m->offset = swap4((uint32_t)m->offset);
m->in_offset = swap4((uint32_t)m->in_offset);
if (!IS_STRING(m->type))
m->value.l = swap4(m->value.l);
m->mask = swap4(m->mask);
}
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