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FILE5_47
src/apprentice.c
3 788 строк
81 KB
Christos Zoulas
PR/683: hgarrereyn: Fix use after free by invalidating the ms->file pointer
08 окт 2025, 19:40
08 окт 2025, 19:40
5a089c7
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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" #ifndef lint FILE_RCSID("@(#)$File: apprentice.c,v 1.369 2025/10/08 16:40:52 christos Exp $") #endif /* lint */ #include "magic.h" #include <stdlib.h> #ifdef HAVE_UNISTD_H #include <unistd.h> #endif #include <stddef.h> #include <string.h> #include <assert.h> #include <ctype.h> #include <fcntl.h> #ifdef QUICK #include <sys/mman.h> #endif #include <dirent.h> #include <limits.h> #ifdef HAVE_BYTESWAP_H #include <byteswap.h> #endif #ifdef HAVE_SYS_BSWAP_H #include <sys/bswap.h> #endif #define EATAB {while (*l && isascii(CAST(unsigned char, *l)) && \ isspace(CAST(unsigned char, *l))) ++l;} #define LOWCASE(l) (isupper(CAST(unsigned char, l)) ? \ tolower(CAST(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 #define ALLOC_CHUNK CAST(size_t, 10) #define ALLOC_INCR CAST(size_t, 200) #define MAP_TYPE_USER 0 #define MAP_TYPE_MALLOC 1 #define MAP_TYPE_MMAP 2 struct magic_entry { struct magic *mp; uint32_t cont_count; uint32_t max_count; }; struct magic_entry_set { struct magic_entry *me; uint32_t count; uint32_t max; }; struct magic_map { void *p; size_t len; int type; struct magic *magic[MAGIC_SETS]; uint32_t nmagic[MAGIC_SETS]; }; file_private int file_formats[FILE_NAMES_SIZE]; file_private const size_t file_nformats = FILE_NAMES_SIZE; file_protected const char *file_names[FILE_NAMES_SIZE]; file_protected const size_t file_nnames = FILE_NAMES_SIZE; file_private int getvalue(struct magic_set *ms, struct magic *, const char **, int); file_private int hextoint(int); file_private const char *getstr(struct magic_set *, struct magic *, const char *, int); file_private int parse(struct magic_set *, struct magic_entry *, const char *, const char *, size_t, int); file_private void eatsize(const char **); file_private int apprentice_1(struct magic_set *, const char *, int); file_private ssize_t apprentice_magic_strength_1(const struct magic *); file_private int apprentice_sort(const void *, const void *); file_private void apprentice_list(struct mlist *, int ); file_private struct magic_map *apprentice_load(struct magic_set *, const char *, int); file_private struct mlist *mlist_alloc(void); file_private void mlist_free_all(struct magic_set *); file_private void mlist_free(struct mlist *); file_private void byteswap(struct magic *, uint32_t); file_private void bs1(struct magic *); #if defined(HAVE_BYTESWAP_H) #define swap2(x) bswap_16(x) #define swap4(x) bswap_32(x) #define swap8(x) bswap_64(x) #elif defined(HAVE_SYS_BSWAP_H) #define swap2(x) bswap16(x) #define swap4(x) bswap32(x) #define swap8(x) bswap64(x) #else file_private uint16_t swap2(uint16_t); file_private uint32_t swap4(uint32_t); file_private uint64_t swap8(uint64_t); #endif file_private char *mkdbname(struct magic_set *, const char *, int); file_private struct magic_map *apprentice_buf(struct magic_set *, struct magic *, size_t); file_private struct magic_map *apprentice_map(struct magic_set *, const char *); file_private int check_buffer(struct magic_set *, struct magic_map *, const char *); file_private void apprentice_unmap(struct magic_map *); file_private int apprentice_compile(struct magic_set *, struct magic_map *, const char *); file_private int check_format_type(const char *, int, const char **); file_private int check_format(struct magic_set *, struct magic *); file_private int get_op(char); file_private int parse_mime(struct magic_set *, struct magic_entry *, const char *, size_t); file_private int parse_strength(struct magic_set *, struct magic_entry *, const char *, size_t); file_private int parse_apple(struct magic_set *, struct magic_entry *, const char *, size_t); file_private int parse_ext(struct magic_set *, struct magic_entry *, const char *, size_t); file_private size_t magicsize = sizeof(struct magic); file_private const char usg_hdr[] = "cont\toffset\ttype\topcode\tmask\tvalue\tdesc"; file_private struct { const char *name; size_t len; int (*fun)(struct magic_set *, struct magic_entry *, const char *, size_t); } bang[] = { #define DECLARE_FIELD(name) { # name, sizeof(# name) - 1, parse_ ## name } DECLARE_FIELD(mime), DECLARE_FIELD(apple), DECLARE_FIELD(ext), DECLARE_FIELD(strength), #undef DECLARE_FIELD { NULL, 0, NULL } }; #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 */ struct type_tbl_s { const char name[16]; const size_t len; const int type; const int format; }; /* * XXX - the actual Single UNIX Specification says that "long" means "long", * as in the C data type, but we treat it as meaning "4-byte integer". * Given that the OS X version of file 5.04 did the same, I guess that passes * the actual test; having "long" be dependent on how big a "long" is on * the machine running "file" is silly. */ static const struct type_tbl_s type_tbl[] = { # define XX(s) s, (sizeof(s) - 1) # define XX_NULL "", 0 { XX("invalid"), FILE_INVALID, FILE_FMT_NONE }, { XX("byte"), FILE_BYTE, FILE_FMT_NUM }, { XX("short"), FILE_SHORT, FILE_FMT_NUM }, { XX("default"), FILE_DEFAULT, FILE_FMT_NONE }, { XX("long"), FILE_LONG, FILE_FMT_NUM }, { XX("string"), FILE_STRING, FILE_FMT_STR }, { XX("date"), FILE_DATE, FILE_FMT_STR }, { XX("beshort"), FILE_BESHORT, FILE_FMT_NUM }, { XX("belong"), FILE_BELONG, FILE_FMT_NUM }, { XX("bedate"), FILE_BEDATE, FILE_FMT_STR }, { XX("leshort"), FILE_LESHORT, FILE_FMT_NUM }, { XX("lelong"), FILE_LELONG, FILE_FMT_NUM }, { XX("ledate"), FILE_LEDATE, FILE_FMT_STR }, { XX("pstring"), FILE_PSTRING, FILE_FMT_STR }, { XX("ldate"), FILE_LDATE, FILE_FMT_STR }, { XX("beldate"), FILE_BELDATE, FILE_FMT_STR }, { XX("leldate"), FILE_LELDATE, FILE_FMT_STR }, { XX("regex"), FILE_REGEX, FILE_FMT_STR }, { XX("bestring16"), FILE_BESTRING16, FILE_FMT_STR }, { XX("lestring16"), FILE_LESTRING16, FILE_FMT_STR }, { XX("search"), FILE_SEARCH, FILE_FMT_STR }, { XX("medate"), FILE_MEDATE, FILE_FMT_STR }, { XX("meldate"), FILE_MELDATE, FILE_FMT_STR }, { XX("melong"), FILE_MELONG, FILE_FMT_NUM }, { XX("quad"), FILE_QUAD, FILE_FMT_QUAD }, { XX("lequad"), FILE_LEQUAD, FILE_FMT_QUAD }, { XX("bequad"), FILE_BEQUAD, FILE_FMT_QUAD }, { XX("qdate"), FILE_QDATE, FILE_FMT_STR }, { XX("leqdate"), FILE_LEQDATE, FILE_FMT_STR }, { XX("beqdate"), FILE_BEQDATE, FILE_FMT_STR }, { XX("qldate"), FILE_QLDATE, FILE_FMT_STR }, { XX("leqldate"), FILE_LEQLDATE, FILE_FMT_STR }, { XX("beqldate"), FILE_BEQLDATE, FILE_FMT_STR }, { XX("float"), FILE_FLOAT, FILE_FMT_FLOAT }, { XX("befloat"), FILE_BEFLOAT, FILE_FMT_FLOAT }, { XX("lefloat"), FILE_LEFLOAT, FILE_FMT_FLOAT }, { XX("double"), FILE_DOUBLE, FILE_FMT_DOUBLE }, { XX("bedouble"), FILE_BEDOUBLE, FILE_FMT_DOUBLE }, { XX("ledouble"), FILE_LEDOUBLE, FILE_FMT_DOUBLE }, { XX("leid3"), FILE_LEID3, FILE_FMT_NUM }, { XX("beid3"), FILE_BEID3, FILE_FMT_NUM }, { XX("indirect"), FILE_INDIRECT, FILE_FMT_NUM }, { XX("qwdate"), FILE_QWDATE, FILE_FMT_STR }, { XX("leqwdate"), FILE_LEQWDATE, FILE_FMT_STR }, { XX("beqwdate"), FILE_BEQWDATE, FILE_FMT_STR }, { XX("name"), FILE_NAME, FILE_FMT_NONE }, { XX("use"), FILE_USE, FILE_FMT_NONE }, { XX("clear"), FILE_CLEAR, FILE_FMT_NONE }, { XX("der"), FILE_DER, FILE_FMT_STR }, { XX("guid"), FILE_GUID, FILE_FMT_STR }, { XX("offset"), FILE_OFFSET, FILE_FMT_QUAD }, { XX("bevarint"), FILE_BEVARINT, FILE_FMT_STR }, { XX("levarint"), FILE_LEVARINT, FILE_FMT_STR }, { XX("msdosdate"), FILE_MSDOSDATE, FILE_FMT_STR }, { XX("lemsdosdate"), FILE_LEMSDOSDATE, FILE_FMT_STR }, { XX("bemsdosdate"), FILE_BEMSDOSDATE, FILE_FMT_STR }, { XX("msdostime"), FILE_MSDOSTIME, FILE_FMT_STR }, { XX("lemsdostime"), FILE_LEMSDOSTIME, FILE_FMT_STR }, { XX("bemsdostime"), FILE_BEMSDOSTIME, FILE_FMT_STR }, { XX("octal"), FILE_OCTAL, FILE_FMT_STR }, { XX_NULL, FILE_INVALID, FILE_FMT_NONE }, }; /* * These are not types, and cannot be preceded by "u" to make them * unsigned. */ static const struct type_tbl_s special_tbl[] = { { XX("der"), FILE_DER, FILE_FMT_STR }, { XX("name"), FILE_NAME, FILE_FMT_STR }, { XX("use"), FILE_USE, FILE_FMT_STR }, { XX("octal"), FILE_OCTAL, FILE_FMT_STR }, { XX_NULL, FILE_INVALID, FILE_FMT_NONE }, }; # undef XX # undef XX_NULL file_private int get_type(const struct type_tbl_s *tbl, const char *l, const char **t) { const struct type_tbl_s *p; for (p = tbl; p->len; p++) { if (strncmp(l, p->name, p->len) == 0) { if (t) *t = l + p->len; break; } } return p->type; } file_private off_t maxoff_t(void) { if (/*CONSTCOND*/sizeof(off_t) == sizeof(int)) return CAST(off_t, INT_MAX); if (/*CONSTCOND*/sizeof(off_t) == sizeof(long)) return CAST(off_t, LONG_MAX); return 0x7fffffff; } file_private int get_standard_integer_type(const char *l, const char **t) { int type; if (l[0] == '\0') return FILE_INVALID; if (l[1] == '\0') return FILE_INVALID; else if (isalpha(CAST(unsigned char, l[1]))) { switch (l[1]) { case 'C': /* "dC" and "uC" */ type = FILE_BYTE; break; case 'S': /* "dS" and "uS" */ type = FILE_SHORT; break; case 'I': case 'L': /* * "dI", "dL", "uI", and "uL". * * XXX - the actual Single UNIX Specification says * that "L" means "long", as in the C data type, * but we treat it as meaning "4-byte integer". * Given that the OS X version of file 5.04 did * the same, I guess that passes the actual SUS * validation suite; having "dL" be dependent on * how big a "long" is on the machine running * "file" is silly. */ type = FILE_LONG; break; case 'Q': /* "dQ" and "uQ" */ type = FILE_QUAD; break; default: /* "d{anything else}", "u{anything else}" */ return FILE_INVALID; } l += 2; } else if (isdigit(CAST(unsigned char, l[1]))) { /* * "d{num}" and "u{num}"; we only support {num} values * of 1, 2, 4, and 8 - the Single UNIX Specification * doesn't say anything about whether arbitrary * values should be supported, but both the Solaris 10 * and OS X Mountain Lion versions of file passed the * Single UNIX Specification validation suite, and * neither of them support values bigger than 8 or * non-power-of-2 values. */ if (isdigit(CAST(unsigned char, l[2]))) { /* Multi-digit, so > 9 */ return FILE_INVALID; } switch (l[1]) { case '1': type = FILE_BYTE; break; case '2': type = FILE_SHORT; break; case '4': type = FILE_LONG; break; case '8': type = FILE_QUAD; break; default: /* XXX - what about 3, 5, 6, or 7? */ return FILE_INVALID; } l += 2; } else { /* * "d" or "u" by itself. */ type = FILE_LONG; ++l; } if (t) *t = l; return type; } file_private void init_file_tables(void) { static int done = 0; const struct type_tbl_s *p; if (done) return; done++; for (p = type_tbl; p->len; p++) { assert(p->type < FILE_NAMES_SIZE); file_names[p->type] = p->name; file_formats[p->type] = p->format; } assert(p - type_tbl == FILE_NAMES_SIZE); } file_private int add_mlist(struct mlist *mlp, struct magic_map *map, size_t idx) { struct mlist *ml; mlp->map = NULL; if ((ml = CAST(struct mlist *, malloc(sizeof(*ml)))) == NULL) return -1; ml->map = idx == 0 ? map : NULL; ml->magic = map->magic[idx]; ml->nmagic = map->nmagic[idx]; if (ml->nmagic) { ml->magic_rxcomp = CAST(file_regex_t **, calloc(ml->nmagic, sizeof(*ml->magic_rxcomp))); if (ml->magic_rxcomp == NULL) { free(ml); return -1; } } else ml->magic_rxcomp = NULL; mlp->prev->next = ml; ml->prev = mlp->prev; ml->next = mlp; mlp->prev = ml; return 0; } /* * Handle one file or directory. */ file_private int apprentice_1(struct magic_set *ms, const char *fn, int action) { struct magic_map *map; #ifndef COMPILE_ONLY size_t i; #endif if (magicsize != FILE_MAGICSIZE) { file_error(ms, 0, "magic element size %lu != %lu", CAST(unsigned long, sizeof(*map->magic[0])), CAST(unsigned long, FILE_MAGICSIZE)); return -1; } if (action == FILE_COMPILE) { map = apprentice_load(ms, fn, action); if (map == NULL) return -1; return apprentice_compile(ms, map, fn); } #ifndef COMPILE_ONLY map = apprentice_map(ms, fn); if (map == NULL) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "using regular magic file `%s'", fn); map = apprentice_load(ms, fn, action); if (map == NULL) return -1; } for (i = 0; i < MAGIC_SETS; i++) { if (add_mlist(ms->mlist[i], map, i) == -1) { /* failed to add to any list, free explicitly */ if (i == 0) apprentice_unmap(map); else mlist_free_all(ms); file_oomem(ms, sizeof(*ms->mlist[0])); return -1; } } if (action == FILE_LIST) { for (i = 0; i < MAGIC_SETS; i++) { printf("Set %" SIZE_T_FORMAT "u:\nBinary patterns:\n", i); apprentice_list(ms->mlist[i], BINTEST); printf("Text patterns:\n"); apprentice_list(ms->mlist[i], TEXTTEST); } } return 0; #else return 0; #endif /* COMPILE_ONLY */ } file_protected void file_ms_free(struct magic_set *ms) { size_t i; if (ms == NULL) return; for (i = 0; i < MAGIC_SETS; i++) mlist_free(ms->mlist[i]); free(ms->o.pbuf); free(ms->o.buf); free(ms->c.li); free(ms->fnamebuf); #ifdef USE_C_LOCALE freelocale(ms->c_lc_ctype); #endif free(ms); } file_protected struct magic_set * file_ms_alloc(int flags) { struct magic_set *ms; size_t i, len; if ((ms = CAST(struct magic_set *, calloc(CAST(size_t, 1u), sizeof(*ms)))) == NULL) return NULL; if (magic_setflags(ms, flags) == -1) { errno = EINVAL; goto free; } ms->o.buf = ms->o.pbuf = NULL; ms->o.blen = 0; len = (ms->c.len = 10) * sizeof(*ms->c.li); if ((ms->c.li = CAST(struct level_info *, malloc(len))) == NULL) goto free; ms->event_flags = 0; ms->error = -1; for (i = 0; i < MAGIC_SETS; i++) ms->mlist[i] = NULL; ms->fnamebuf = NULL; ms->file = "unknown"; ms->line = 0; ms->magwarn = 0; ms->indir_max = FILE_INDIR_MAX; ms->name_max = FILE_NAME_MAX; ms->elf_shnum_max = FILE_ELF_SHNUM_MAX; ms->elf_shsize_max = FILE_ELF_SHSIZE_MAX; ms->elf_phnum_max = FILE_ELF_PHNUM_MAX; ms->elf_notes_max = FILE_ELF_NOTES_MAX; ms->regex_max = FILE_REGEX_MAX; ms->bytes_max = FILE_BYTES_MAX; ms->encoding_max = FILE_ENCODING_MAX; ms->magwarn_max = FILE_MAGWARN_MAX; #ifdef USE_C_LOCALE ms->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0); assert(ms->c_lc_ctype != NULL); #endif return ms; free: free(ms); return NULL; } file_private void apprentice_unmap(struct magic_map *map) { size_t i; char *p; if (map == NULL) return; switch (map->type) { case MAP_TYPE_USER: break; case MAP_TYPE_MALLOC: p = CAST(char *, map->p); for (i = 0; i < MAGIC_SETS; i++) { char *b = RCAST(char *, map->magic[i]); if (p != NULL && b >= p && b <= p + map->len) continue; free(b); } free(p); break; #ifdef QUICK case MAP_TYPE_MMAP: if (map->p && map->p != MAP_FAILED) (void)munmap(map->p, map->len); break; #endif default: fprintf(stderr, "Bad map type %d", map->type); abort(); } free(map); } file_private struct mlist * mlist_alloc(void) { struct mlist *mlist; if ((mlist = CAST(struct mlist *, calloc(1, sizeof(*mlist)))) == NULL) { return NULL; } mlist->next = mlist->prev = mlist; return mlist; } file_private void mlist_free_all(struct magic_set *ms) { size_t i; for (i = 0; i < MAGIC_SETS; i++) { mlist_free(ms->mlist[i]); ms->mlist[i] = NULL; } } file_private void mlist_free_one(struct mlist *ml) { size_t i; if (ml->map) apprentice_unmap(CAST(struct magic_map *, ml->map)); for (i = 0; i < ml->nmagic; ++i) { if (ml->magic_rxcomp[i]) { file_regfree(ml->magic_rxcomp[i]); free(ml->magic_rxcomp[i]); ml->magic_rxcomp[i] = NULL; } } free(ml->magic_rxcomp); ml->magic_rxcomp = NULL; free(ml); } file_private void mlist_free(struct mlist *mlist) { struct mlist *ml, *next; if (mlist == NULL) return; for (ml = mlist->next; ml != mlist;) { next = ml->next; mlist_free_one(ml); ml = next; } mlist_free_one(mlist); } #ifndef COMPILE_ONLY /* void **bufs: an array of compiled magic files */ file_protected int buffer_apprentice(struct magic_set *ms, struct magic **bufs, size_t *sizes, size_t nbufs) { size_t i, j; struct magic_map *map; if (nbufs == 0) return -1; (void)file_reset(ms, 0); init_file_tables(); for (i = 0; i < MAGIC_SETS; i++) { mlist_free(ms->mlist[i]); if ((ms->mlist[i] = mlist_alloc()) == NULL) { file_oomem(ms, sizeof(*ms->mlist[0])); goto fail; } } for (i = 0; i < nbufs; i++) { map = apprentice_buf(ms, bufs[i], sizes[i]); if (map == NULL) goto fail; for (j = 0; j < MAGIC_SETS; j++) { if (add_mlist(ms->mlist[j], map, j) == -1) { file_oomem(ms, sizeof(*ms->mlist[0])); goto fail; } } } return 0; fail: mlist_free_all(ms); return -1; } #endif /* const char *fn: list of magic files and directories */ file_protected int file_apprentice(struct magic_set *ms, const char *fn, int action) { char *p; int fileerr, errs = -1; size_t i, j; (void)file_reset(ms, 0); if ((fn = magic_getpath(fn, action)) == NULL) return -1; init_file_tables(); free(ms->fnamebuf); ms->file = NULL; if ((ms->fnamebuf = strdup(fn)) == NULL) { file_oomem(ms, strlen(fn)); return -1; } for (i = 0; i < MAGIC_SETS; i++) { mlist_free(ms->mlist[i]); if ((ms->mlist[i] = mlist_alloc()) == NULL) { file_oomem(ms, sizeof(*ms->mlist[0])); for (j = 0; j < i; j++) { mlist_free(ms->mlist[j]); ms->mlist[j] = NULL; } return -1; } } fn = ms->fnamebuf; while (fn) { p = CCAST(char *, strchr(fn, PATHSEP)); if (p) *p++ = '\0'; if (*fn == '\0') break; fileerr = apprentice_1(ms, fn, action); errs = MAX(errs, fileerr); fn = p; } if (errs == -1) { for (i = 0; i < MAGIC_SETS; i++) { mlist_free(ms->mlist[i]); ms->mlist[i] = NULL; } file_error(ms, 0, "could not find any valid magic files!"); return -1; } #if 0 /* * Always leave the database loaded */ if (action == FILE_LOAD) return 0; for (i = 0; i < MAGIC_SETS; i++) { mlist_free(ms->mlist[i]); ms->mlist[i] = NULL; } #endif switch (action) { case FILE_LOAD: case FILE_COMPILE: case FILE_CHECK: case FILE_LIST: return 0; default: file_error(ms, 0, "Invalid action %d", action); return -1; } } /* * Compute the real length of a magic expression, for the purposes * of determining how "strong" a magic expression is (approximating * how specific its matches are): * - magic characters count 0 unless escaped. * - [] expressions count 1 * - {} expressions count 0 * - regular characters or escaped magic characters count 1 * - 0 length expressions count as one */ file_private size_t nonmagic(const char *str) { const char *p; size_t rv = 0; for (p = str; *p; p++) switch (*p) { case '\\': /* Escaped anything counts 1 */ if (!*++p) p--; rv++; continue; case '?': /* Magic characters count 0 */ case '*': case '.': case '+': case '^': case '$': continue; case '[': /* Bracketed expressions count 1 the ']' */ while (*p && *p != ']') p++; p--; continue; case '{': /* Braced expressions count 0 */ while (*p && *p != '}') p++; if (!*p) p--; continue; default: /* Anything else counts 1 */ rv++; continue; } return rv == 0 ? 1 : rv; /* Return at least 1 */ } file_private size_t typesize(int type) { switch (type) { case FILE_BYTE: return 1; case FILE_SHORT: case FILE_LESHORT: case FILE_BESHORT: case FILE_MSDOSDATE: case FILE_BEMSDOSDATE: case FILE_LEMSDOSDATE: case FILE_MSDOSTIME: case FILE_BEMSDOSTIME: case FILE_LEMSDOSTIME: return 2; case FILE_LONG: case FILE_LELONG: case FILE_BELONG: case FILE_MELONG: return 4; case FILE_DATE: case FILE_LEDATE: case FILE_BEDATE: case FILE_MEDATE: case FILE_LDATE: case FILE_LELDATE: case FILE_BELDATE: case FILE_MELDATE: case FILE_FLOAT: case FILE_BEFLOAT: case FILE_LEFLOAT: case FILE_BEID3: case FILE_LEID3: return 4; case FILE_QUAD: case FILE_BEQUAD: case FILE_LEQUAD: case FILE_QDATE: case FILE_LEQDATE: case FILE_BEQDATE: case FILE_QLDATE: case FILE_LEQLDATE: case FILE_BEQLDATE: case FILE_QWDATE: case FILE_LEQWDATE: case FILE_BEQWDATE: case FILE_DOUBLE: case FILE_BEDOUBLE: case FILE_LEDOUBLE: case FILE_OFFSET: case FILE_BEVARINT: case FILE_LEVARINT: return 8; case FILE_GUID: return 16; default: return FILE_BADSIZE; } } /* * Get weight of this magic entry, for sorting purposes. */ file_private ssize_t apprentice_magic_strength_1(const struct magic *m) { #define MULT 10U size_t ts, v; ssize_t val = 2 * MULT; /* baseline strength */ switch (m->type) { case FILE_DEFAULT: /* make sure this sorts last */ if (m->factor_op != FILE_FACTOR_OP_NONE) { file_magwarn1("Unsupported factor_op in default %d", m->factor_op); } return 0; case FILE_BYTE: case FILE_SHORT: case FILE_LESHORT: case FILE_BESHORT: case FILE_LONG: case FILE_LELONG: case FILE_BELONG: case FILE_MELONG: case FILE_DATE: case FILE_LEDATE: case FILE_BEDATE: case FILE_MEDATE: case FILE_LDATE: case FILE_LELDATE: case FILE_BELDATE: case FILE_MELDATE: case FILE_FLOAT: case FILE_BEFLOAT: case FILE_LEFLOAT: case FILE_QUAD: case FILE_BEQUAD: case FILE_LEQUAD: case FILE_QDATE: case FILE_LEQDATE: case FILE_BEQDATE: case FILE_QLDATE: case FILE_LEQLDATE: case FILE_BEQLDATE: case FILE_QWDATE: case FILE_LEQWDATE: case FILE_BEQWDATE: case FILE_DOUBLE: case FILE_BEDOUBLE: case FILE_LEDOUBLE: case FILE_BEVARINT: case FILE_LEVARINT: case FILE_GUID: case FILE_BEID3: case FILE_LEID3: case FILE_OFFSET: case FILE_MSDOSDATE: case FILE_BEMSDOSDATE: case FILE_LEMSDOSDATE: case FILE_MSDOSTIME: case FILE_BEMSDOSTIME: case FILE_LEMSDOSTIME: ts = typesize(m->type); if (ts == FILE_BADSIZE) { (void)fprintf(stderr, "Bad size for type %d\n", m->type); abort(); } val += ts * MULT; break; case FILE_PSTRING: case FILE_STRING: case FILE_OCTAL: val += m->vallen * MULT; break; case FILE_BESTRING16: case FILE_LESTRING16: val += m->vallen * MULT / 2; break; case FILE_SEARCH: if (m->vallen == 0) break; val += m->vallen * MAX(MULT / m->vallen, 1); break; case FILE_REGEX: v = nonmagic(m->value.s); val += v * MAX(MULT / v, 1); break; case FILE_INDIRECT: case FILE_NAME: case FILE_USE: case FILE_CLEAR: break; case FILE_DER: val += MULT; break; default: (void)fprintf(stderr, "Bad type %d\n", m->type); abort(); } switch (m->reln) { case 'x': /* matches anything penalize */ case '!': /* matches almost anything penalize */ val = 0; break; case '=': /* Exact match, prefer */ val += MULT; break; case '>': case '<': /* comparison match reduce strength */ val -= 2 * MULT; break; case '^': case '&': /* masking bits, we could count them too */ val -= MULT; break; default: (void)fprintf(stderr, "Bad relation %c\n", m->reln); abort(); } return val; } /*ARGSUSED*/ file_protected size_t file_magic_strength(const struct magic *m, size_t nmagic __attribute__((__unused__))) { ssize_t val = apprentice_magic_strength_1(m); #ifdef notyet if (m->desc[0] == '\0') { size_t i; /* * Magic entries with no description get their continuations * added */ for (i = 1; m[i].cont_level != 0 && i < MIN(nmagic, 3); i++) { ssize_t v = apprentice_magic_strength_1(&m[i]) >> (i + 1); val += v; if (m[i].desc[0] != '\0') break; } } #endif switch (m->factor_op) { case FILE_FACTOR_OP_NONE: break; case FILE_FACTOR_OP_PLUS: val += m->factor; break; case FILE_FACTOR_OP_MINUS: val -= m->factor; break; case FILE_FACTOR_OP_TIMES: val *= m->factor; break; case FILE_FACTOR_OP_DIV: val /= m->factor; break; default: (void)fprintf(stderr, "Bad factor_op %u\n", m->factor_op); abort(); } if (val <= 0) /* ensure we only return 0 for FILE_DEFAULT */ val = 1; #ifndef notyet /* * Magic entries with no description get a bonus because they depend * on subsequent magic entries to print something. */ if (m->desc[0] == '\0') val++; #endif return val; } /* * Sort callback for sorting entries by "strength" (basically length) */ file_private int apprentice_sort(const void *a, const void *b) { const struct magic_entry *ma = CAST(const struct magic_entry *, a); const struct magic_entry *mb = CAST(const struct magic_entry *, b); size_t sa = file_magic_strength(ma->mp, ma->cont_count); size_t sb = file_magic_strength(mb->mp, mb->cont_count); if (sa == sb) { struct magic mpa = *ma->mp; struct magic mpb = *mb->mp; mpa.lineno = mpb.lineno = 0; int x = memcmp(&mpa, &mpb, sizeof(mpa)); if (x == 0) { // Don't warn for DER if (mpa.type == FILE_DER) return 0; file_magwarn1("Duplicate magic entry `%s'", ma->mp->desc); #ifndef COMPILE_ONLY file_mdump(ma->mp); file_mdump(mb->mp); #endif return 0; } return x > 0 ? -1 : 1; } return sa > sb ? -1 : 1; } /* * Shows sorted patterns list in the order which is used for the matching */ file_private void apprentice_list(struct mlist *mlist, int mode) { uint32_t magindex, descindex, mimeindex, lineindex; struct mlist *ml; for (ml = mlist->next; ml != mlist; ml = ml->next) { for (magindex = 0; magindex < ml->nmagic; magindex++) { struct magic *m = &ml->magic[magindex]; if ((m->flag & mode) != mode) { /* Skip sub-tests */ while (magindex + 1 < ml->nmagic && ml->magic[magindex + 1].cont_level != 0) ++magindex; continue; /* Skip to next top-level test*/ } /* * Try to iterate over the tree until we find item with * description/mimetype. */ lineindex = descindex = mimeindex = magindex; for (; magindex + 1 < ml->nmagic && ml->magic[magindex + 1].cont_level != 0; magindex++) { uint32_t mi = magindex + 1; if (*ml->magic[descindex].desc == '\0' && *ml->magic[mi].desc) descindex = mi; if (*ml->magic[mimeindex].mimetype == '\0' && *ml->magic[mi].mimetype) mimeindex = mi; } printf("Strength = %3" SIZE_T_FORMAT "u@%u: %s [%s]\n", file_magic_strength(m, ml->nmagic - magindex), ml->magic[lineindex].lineno, ml->magic[descindex].desc, ml->magic[mimeindex].mimetype); } } } file_private void set_test_type(struct magic *mstart, struct magic *m) { switch (m->type) { case FILE_BYTE: case FILE_SHORT: case FILE_LONG: case FILE_DATE: case FILE_BESHORT: case FILE_BELONG: case FILE_BEDATE: case FILE_LESHORT: case FILE_LELONG: case FILE_LEDATE: case FILE_LDATE: case FILE_BELDATE: case FILE_LELDATE: case FILE_MEDATE: case FILE_MELDATE: case FILE_MELONG: case FILE_QUAD: case FILE_LEQUAD: case FILE_BEQUAD: case FILE_QDATE: case FILE_LEQDATE: case FILE_BEQDATE: case FILE_QLDATE: case FILE_LEQLDATE: case FILE_BEQLDATE: case FILE_QWDATE: case FILE_LEQWDATE: case FILE_BEQWDATE: case FILE_FLOAT: case FILE_BEFLOAT: case FILE_LEFLOAT: case FILE_DOUBLE: case FILE_BEDOUBLE: case FILE_LEDOUBLE: case FILE_BEVARINT: case FILE_LEVARINT: case FILE_DER: case FILE_GUID: case FILE_OFFSET: case FILE_MSDOSDATE: case FILE_BEMSDOSDATE: case FILE_LEMSDOSDATE: case FILE_MSDOSTIME: case FILE_BEMSDOSTIME: case FILE_LEMSDOSTIME: case FILE_OCTAL: mstart->flag |= BINTEST; break; case FILE_STRING: case FILE_PSTRING: case FILE_BESTRING16: case FILE_LESTRING16: case FILE_REGEX: case FILE_SEARCH: /* Check for override */ if (mstart->str_flags & STRING_BINTEST) mstart->flag |= BINTEST; if (mstart->str_flags & STRING_TEXTTEST) mstart->flag |= TEXTTEST; if (mstart->flag & (TEXTTEST|BINTEST)) break; /* * XXX: Compatibility: For string types assume binary match * in reality it is better in the long term to change all * the magic to be string/b where appropriate */ if (m->type != FILE_REGEX && m->type != FILE_SEARCH) { mstart->flag |= BINTEST; break; } /* binary test if pattern is not text */ if (file_looks_utf8(m->value.us, CAST(size_t, m->vallen), NULL, NULL) <= 0) mstart->flag |= BINTEST; else mstart->flag |= TEXTTEST; break; case FILE_DEFAULT: /* can't deduce anything; we shouldn't see this at the top level anyway */ break; case FILE_INVALID: default: /* invalid search type, but no need to complain here */ break; } } file_private int addentry(struct magic_set *ms, struct magic_entry *me, struct magic_entry_set *mset) { size_t i = me->mp->type == FILE_NAME ? 1 : 0; if (mset[i].me == NULL || mset[i].count == mset[i].max) { struct magic_entry *mp; size_t incr = mset[i].max + ALLOC_INCR; if ((mp = CAST(struct magic_entry *, realloc(mset[i].me, sizeof(*mp) * incr))) == NULL) { file_oomem(ms, sizeof(*mp) * incr); return -1; } (void)memset(&mp[mset[i].count], 0, sizeof(*mp) * ALLOC_INCR); mset[i].me = mp; mset[i].max = CAST(uint32_t, incr); assert(mset[i].max == incr); } mset[i].me[mset[i].count++] = *me; memset(me, 0, sizeof(*me)); return 0; } /* * Load and parse one file. */ file_private void load_1(struct magic_set *ms, int action, const char *fn, int *errs, struct magic_entry_set *mset) { size_t lineno = 0, llen = 0; char *line = NULL; ssize_t len; struct magic_entry me; FILE *f = fopen(ms->file = fn, "r"); if (f == NULL) { if (errno != ENOENT) file_error(ms, errno, "cannot read magic file `%s'", fn); (*errs)++; return; } memset(&me, 0, sizeof(me)); /* read and parse this file */ for (ms->line = 1; (len = getline(&line, &llen, f)) != -1; ms->line++) { if (ms->magwarn >= ms->magwarn_max) break; if (len == 0) /* null line, garbage, etc */ continue; if (line[len - 1] == '\n') { lineno++; line[len - 1] = '\0'; /* delete newline */ } switch (line[0]) { case '\0': /* empty, do not parse */ case '#': /* comment, do not parse */ continue; case '!': if (line[1] == ':') { size_t i; for (i = 0; bang[i].name != NULL; i++) { if (CAST(size_t, len - 2) > bang[i].len && memcmp(bang[i].name, line + 2, bang[i].len) == 0) break; } if (bang[i].name == NULL) { file_error(ms, 0, "Unknown !: entry `%s'", line); (*errs)++; continue; } if (me.mp == NULL) { file_error(ms, 0, "No current entry for :!%s type", bang[i].name); (*errs)++; continue; } if ((*bang[i].fun)(ms, &me, line + bang[i].len + 2, len - bang[i].len - 2) != 0) { (*errs)++; continue; } continue; } /*FALLTHROUGH*/ default: again: switch (parse(ms, &me, fn, line, lineno, action)) { case 0: continue; case 1: (void)addentry(ms, &me, mset); goto again; default: (*errs)++; break; } } } if (me.mp) (void)addentry(ms, &me, mset); free(line); (void)fclose(f); } /* * parse a file or directory of files * const char *fn: name of magic file or directory */ file_private int cmpstrp(const void *p1, const void *p2) { return strcmp(*RCAST(char *const *, p1), *RCAST(char *const *, p2)); } file_private uint32_t set_text_binary(struct magic_set *ms, struct magic_entry *me, uint32_t nme, uint32_t starttest) { static const char text[] = "text"; static const char binary[] = "binary"; static const size_t len = sizeof(text); uint32_t i = starttest; do { set_test_type(me[starttest].mp, me[i].mp); if ((ms->flags & MAGIC_DEBUG) == 0) continue; (void)fprintf(stderr, "%s%s%s: %s\n", me[i].mp->mimetype, me[i].mp->mimetype[0] == '\0' ? "" : "; ", me[i].mp->desc[0] ? me[i].mp->desc : "(no description)", me[i].mp->flag & BINTEST ? binary : text); if (me[i].mp->flag & BINTEST) { char *p = strstr(me[i].mp->desc, text); if (p && (p == me[i].mp->desc || isspace(CAST(unsigned char, p[-1]))) && (p + len - me[i].mp->desc == MAXstring || (p[len] == '\0' || isspace(CAST(unsigned char, p[len]))))) (void)fprintf(stderr, "*** Possible " "binary test for text type\n"); } } while (++i < nme && me[i].mp->cont_level != 0); return i; } file_private void set_last_default(struct magic_set *ms, struct magic_entry *me, uint32_t nme) { uint32_t i; for (i = 0; i < nme; i++) { if (me[i].mp->cont_level == 0 && me[i].mp->type == FILE_DEFAULT) { while (++i < nme) if (me[i].mp->cont_level == 0) break; if (i != nme) { /* XXX - Ugh! */ ms->line = me[i].mp->lineno; file_magwarn(ms, "level 0 \"default\" did not sort last"); } return; } } } file_private int coalesce_entries(struct magic_set *ms, struct magic_entry *me, uint32_t nme, struct magic **ma, uint32_t *nma) { uint32_t i, mentrycount = 0; size_t slen; for (i = 0; i < nme; i++) mentrycount += me[i].cont_count; if (mentrycount == 0) { *ma = NULL; *nma = 0; return 0; } slen = sizeof(**ma) * mentrycount; if ((*ma = CAST(struct magic *, malloc(slen))) == NULL) { file_oomem(ms, slen); return -1; } mentrycount = 0; for (i = 0; i < nme; i++) { (void)memcpy(*ma + mentrycount, me[i].mp, me[i].cont_count * sizeof(**ma)); mentrycount += me[i].cont_count; } *nma = mentrycount; return 0; } file_private void magic_entry_free(struct magic_entry *me, uint32_t nme) { uint32_t i; if (me == NULL) return; for (i = 0; i < nme; i++) free(me[i].mp); free(me); } file_private struct magic_map * apprentice_load(struct magic_set *ms, const char *fn, int action) { int errs = 0; uint32_t i, j; size_t files = 0, maxfiles = 0; char **filearr = NULL, *mfn; struct stat st; struct magic_map *map; struct magic_entry_set mset[MAGIC_SETS]; DIR *dir; struct dirent *d; memset(mset, 0, sizeof(mset)); ms->flags |= MAGIC_CHECK; /* Enable checks for parsed files */ if ((map = CAST(struct magic_map *, calloc(1, sizeof(*map)))) == NULL) { file_oomem(ms, sizeof(*map)); return NULL; } map->type = MAP_TYPE_MALLOC; /* print silly verbose header for USG compat. */ if (action == FILE_CHECK) (void)fprintf(stderr, "%s\n", usg_hdr); /* load directory or file */ if (stat(fn, &st) == 0 && S_ISDIR(st.st_mode)) { dir = opendir(fn); if (!dir) { errs++; goto out; } while ((d = readdir(dir)) != NULL) { if (d->d_name[0] == '.') continue; if (asprintf(&mfn, "%s/%s", fn, d->d_name) < 0) { file_oomem(ms, strlen(fn) + strlen(d->d_name) + 2); errs++; closedir(dir); goto out; } if (stat(mfn, &st) == -1 || !S_ISREG(st.st_mode)) { free(mfn); continue; } if (files >= maxfiles) { size_t mlen; char **nfilearr; maxfiles = (maxfiles + 1) * 2; mlen = maxfiles * sizeof(*filearr); if ((nfilearr = CAST(char **, realloc(filearr, mlen))) == NULL) { file_oomem(ms, mlen); free(mfn); closedir(dir); errs++; goto out; } filearr = nfilearr; } filearr[files++] = mfn; } closedir(dir); if (filearr) { qsort(filearr, files, sizeof(*filearr), cmpstrp); for (i = 0; i < files; i++) { load_1(ms, action, filearr[i], &errs, mset); free(filearr[i]); } free(filearr); filearr = NULL; } } else load_1(ms, action, fn, &errs, mset); if (errs) goto out; for (j = 0; j < MAGIC_SETS; j++) { /* Set types of tests */ for (i = 0; i < mset[j].count; ) { if (mset[j].me[i].mp->cont_level != 0) { i++; continue; } i = set_text_binary(ms, mset[j].me, mset[j].count, i); } if (mset[j].me) qsort(mset[j].me, mset[j].count, sizeof(*mset[0].me), apprentice_sort); /* * Make sure that any level 0 "default" line is last * (if one exists). */ set_last_default(ms, mset[j].me, mset[j].count); /* coalesce per file arrays into a single one, if needed */ if (mset[j].count == 0) continue; if (coalesce_entries(ms, mset[j].me, mset[j].count, &map->magic[j], &map->nmagic[j]) == -1) { errs++; goto out; } } out: free(filearr); for (j = 0; j < MAGIC_SETS; j++) magic_entry_free(mset[j].me, mset[j].count); if (errs) { apprentice_unmap(map); return NULL; } return map; } /* * extend the sign bit if the comparison is to be signed */ file_protected uint64_t file_signextend(struct magic_set *ms, struct magic *m, uint64_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 = CAST(signed char, v); break; case FILE_SHORT: case FILE_BESHORT: case FILE_LESHORT: v = CAST(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: case FILE_FLOAT: case FILE_BEFLOAT: case FILE_LEFLOAT: case FILE_MSDOSDATE: case FILE_BEMSDOSDATE: case FILE_LEMSDOSDATE: case FILE_MSDOSTIME: case FILE_BEMSDOSTIME: case FILE_LEMSDOSTIME: v = CAST(int32_t, v); break; case FILE_QUAD: case FILE_BEQUAD: case FILE_LEQUAD: case FILE_QDATE: case FILE_QLDATE: case FILE_QWDATE: case FILE_BEQDATE: case FILE_BEQLDATE: case FILE_BEQWDATE: case FILE_LEQDATE: case FILE_LEQLDATE: case FILE_LEQWDATE: case FILE_DOUBLE: case FILE_BEDOUBLE: case FILE_LEDOUBLE: case FILE_OFFSET: case FILE_BEVARINT: case FILE_LEVARINT: v = CAST(int64_t, v); break; case FILE_STRING: case FILE_PSTRING: case FILE_BESTRING16: case FILE_LESTRING16: case FILE_REGEX: case FILE_SEARCH: case FILE_DEFAULT: case FILE_INDIRECT: case FILE_NAME: case FILE_USE: case FILE_CLEAR: case FILE_DER: case FILE_GUID: case FILE_OCTAL: break; default: if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "cannot happen: m->type=%d\n", m->type); return FILE_BADSIZE; } } return v; } file_private int string_modifier_check(struct magic_set *ms, struct magic *m) { if ((ms->flags & MAGIC_CHECK) == 0) return 0; if ((m->type != FILE_REGEX || (m->str_flags & REGEX_LINE_COUNT) == 0) && (m->type != FILE_PSTRING && (m->str_flags & PSTRING_LEN) != 0)) { file_magwarn(ms, "'/BHhLl' modifiers are only allowed for pascal strings\n"); return -1; } switch (m->type) { case FILE_BESTRING16: case FILE_LESTRING16: if (m->str_flags != 0) { file_magwarn(ms, "no modifiers allowed for 16-bit strings\n"); return -1; } break; case FILE_STRING: case FILE_PSTRING: if ((m->str_flags & REGEX_OFFSET_START) != 0) { file_magwarn(ms, "'/%c' only allowed on regex and search\n", CHAR_REGEX_OFFSET_START); return -1; } break; case FILE_SEARCH: if (m->str_range == 0) { file_magwarn(ms, "missing range; defaulting to %d\n", STRING_DEFAULT_RANGE); m->str_range = STRING_DEFAULT_RANGE; return -1; } break; case FILE_REGEX: if ((m->str_flags & STRING_COMPACT_WHITESPACE) != 0) { file_magwarn(ms, "'/%c' not allowed on regex\n", CHAR_COMPACT_WHITESPACE); return -1; } if ((m->str_flags & STRING_COMPACT_OPTIONAL_WHITESPACE) != 0) { file_magwarn(ms, "'/%c' not allowed on regex\n", CHAR_COMPACT_OPTIONAL_WHITESPACE); return -1; } if ((m->str_flags & STRING_IGNORE_LOWERCASE) != 0) { file_magwarn(ms, "'/%c' not allowed on regex\n", CHAR_IGNORE_LOWERCASE); return -1; } if ((m->str_flags & STRING_IGNORE_UPPERCASE) != 0) { file_magwarn(ms, "'/%c' not allowed on regex\n", CHAR_IGNORE_UPPERCASE); return -1; } break; default: file_magwarn(ms, "coding error: m->type=%d\n", m->type); return -1; } return 0; } file_private int get_op(char c) { switch (c) { case '&': return FILE_OPAND; case '|': return FILE_OPOR; case '^': return FILE_OPXOR; case '+': return FILE_OPADD; case '-': return FILE_OPMINUS; case '*': return FILE_OPMULTIPLY; case '/': return FILE_OPDIVIDE; case '%': return FILE_OPMODULO; default: return -1; } } #ifdef ENABLE_CONDITIONALS file_private int get_cond(const char *l, const char **t) { static const struct cond_tbl_s { char name[8]; size_t len; int cond; } cond_tbl[] = { { "if", 2, COND_IF }, { "elif", 4, COND_ELIF }, { "else", 4, COND_ELSE }, { "", 0, COND_NONE }, }; const struct cond_tbl_s *p; for (p = cond_tbl; p->len; p++) { if (strncmp(l, p->name, p->len) == 0 && isspace(CAST(unsigned char, l[p->len]))) { if (t) *t = l + p->len; break; } } return p->cond; } file_private int check_cond(struct magic_set *ms, int cond, uint32_t cont_level) { int last_cond; last_cond = ms->c.li[cont_level].last_cond; switch (cond) { case COND_IF: if (last_cond != COND_NONE && last_cond != COND_ELIF) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "syntax error: `if'"); return -1; } last_cond = COND_IF; break; case COND_ELIF: if (last_cond != COND_IF && last_cond != COND_ELIF) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "syntax error: `elif'"); return -1; } last_cond = COND_ELIF; break; case COND_ELSE: if (last_cond != COND_IF && last_cond != COND_ELIF) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "syntax error: `else'"); return -1; } last_cond = COND_NONE; break; case COND_NONE: last_cond = COND_NONE; break; } ms->c.li[cont_level].last_cond = last_cond; return 0; } #endif /* ENABLE_CONDITIONALS */ file_private int parse_indirect_modifier(struct magic_set *ms, struct magic *m, const char **lp) { const char *l = *lp; while (!isspace(CAST(unsigned char, *++l))) switch (*l) { case CHAR_INDIRECT_RELATIVE: m->str_flags |= INDIRECT_RELATIVE; break; default: if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "indirect modifier `%c' " "invalid", *l); *lp = l; return -1; } *lp = l; return 0; } file_private void parse_op_modifier(struct magic_set *ms, struct magic *m, const char **lp, int op) { const char *l = *lp; char *t; uint64_t val; ++l; m->mask_op |= op; val = CAST(uint64_t, strtoull(l, &t, 0)); l = t; m->num_mask = file_signextend(ms, m, val); eatsize(&l); *lp = l; } file_private int parse_string_modifier(struct magic_set *ms, struct magic *m, const char **lp) { const char *l = *lp; char *t; int have_range = 0; while (!isspace(CAST(unsigned char, *++l))) { switch (*l) { case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (have_range && (ms->flags & MAGIC_CHECK)) file_magwarn(ms, "multiple ranges"); have_range = 1; m->str_range = CAST(uint32_t, strtoul(l, &t, 0)); if (m->str_range == 0) file_magwarn(ms, "zero range"); l = t - 1; break; case CHAR_COMPACT_WHITESPACE: m->str_flags |= STRING_COMPACT_WHITESPACE; break; case CHAR_COMPACT_OPTIONAL_WHITESPACE: m->str_flags |= STRING_COMPACT_OPTIONAL_WHITESPACE; break; case CHAR_IGNORE_LOWERCASE: m->str_flags |= STRING_IGNORE_LOWERCASE; break; case CHAR_IGNORE_UPPERCASE: m->str_flags |= STRING_IGNORE_UPPERCASE; break; case CHAR_REGEX_OFFSET_START: m->str_flags |= REGEX_OFFSET_START; break; case CHAR_BINTEST: m->str_flags |= STRING_BINTEST; break; case CHAR_TEXTTEST: m->str_flags |= STRING_TEXTTEST; break; case CHAR_TRIM: m->str_flags |= STRING_TRIM; break; case CHAR_FULL_WORD: m->str_flags |= STRING_FULL_WORD; break; case CHAR_PSTRING_1_LE: #define SET_LENGTH(a) m->str_flags = (m->str_flags & ~PSTRING_LEN) | (a) if (m->type != FILE_PSTRING) goto bad; SET_LENGTH(PSTRING_1_LE); break; case CHAR_PSTRING_2_BE: if (m->type != FILE_PSTRING) goto bad; SET_LENGTH(PSTRING_2_BE); break; case CHAR_PSTRING_2_LE: if (m->type != FILE_PSTRING) goto bad; SET_LENGTH(PSTRING_2_LE); break; case CHAR_PSTRING_4_BE: if (m->type != FILE_PSTRING) goto bad; SET_LENGTH(PSTRING_4_BE); break; case CHAR_PSTRING_4_LE: switch (m->type) { case FILE_PSTRING: case FILE_REGEX: break; default: goto bad; } SET_LENGTH(PSTRING_4_LE); break; case CHAR_PSTRING_LENGTH_INCLUDES_ITSELF: if (m->type != FILE_PSTRING) goto bad; m->str_flags |= PSTRING_LENGTH_INCLUDES_ITSELF; break; default: bad: if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "string modifier `%c' " "invalid", *l); goto out; } /* allow multiple '/' for readability */ if (l[1] == '/' && !isspace(CAST(unsigned char, l[2]))) l++; } if (string_modifier_check(ms, m) == -1) goto out; *lp = l; return 0; out: *lp = l; return -1; } /* * parse one line from magic file, put into magic[index++] if valid */ file_private int parse(struct magic_set *ms, struct magic_entry *me, const char *file, const char *line, size_t lineno, int action) { #ifdef ENABLE_CONDITIONALS static uint32_t last_cont_level = 0; #endif size_t i; struct magic *m; const char *l = line; char *t; int op; uint32_t cont_level; int32_t diff; cont_level = 0; /* * Parse the offset. */ while (*l == '>') { ++l; /* step over */ cont_level++; } #ifdef ENABLE_CONDITIONALS if (cont_level == 0 || cont_level > last_cont_level) if (file_check_mem(ms, cont_level) == -1) return -1; last_cont_level = cont_level; #endif if (cont_level != 0) { if (me->mp == NULL) { file_magerror(ms, "No current entry for continuation"); return -1; } if (me->cont_count == 0) { file_magerror(ms, "Continuations present with 0 count"); return -1; } m = &me->mp[me->cont_count - 1]; diff = CAST(int32_t, cont_level) - CAST(int32_t, m->cont_level); if (diff > 1) file_magwarn(ms, "New continuation level %u is more " "than one larger than current level %u", cont_level, m->cont_level); if (me->cont_count == me->max_count) { struct magic *nm; size_t cnt = me->max_count + ALLOC_CHUNK; if ((nm = CAST(struct magic *, realloc(me->mp, sizeof(*nm) * cnt))) == NULL) { file_oomem(ms, sizeof(*nm) * cnt); return -1; } me->mp = nm; me->max_count = CAST(uint32_t, cnt); } m = &me->mp[me->cont_count++]; (void)memset(m, 0, sizeof(*m)); m->cont_level = cont_level; } else { static const size_t len = sizeof(*m) * ALLOC_CHUNK; if (me->mp != NULL) return 1; if ((m = CAST(struct magic *, malloc(len))) == NULL) { file_oomem(ms, len); return -1; } me->mp = m; me->max_count = ALLOC_CHUNK; (void)memset(m, 0, sizeof(*m)); m->factor_op = FILE_FACTOR_OP_NONE; m->cont_level = 0; me->cont_count = 1; } m->lineno = CAST(uint32_t, lineno); if (*l == '&') { /* m->cont_level == 0 checked below. */ ++l; /* step over */ m->flag |= OFFADD; } if (*l == '(') { ++l; /* step over */ m->flag |= INDIR; if (m->flag & OFFADD) m->flag = (m->flag & ~OFFADD) | INDIROFFADD; if (*l == '&') { /* m->cont_level == 0 checked below */ ++l; /* step over */ m->flag |= OFFADD; } } /* Indirect offsets are not valid at level 0. */ if (m->cont_level == 0 && (m->flag & (OFFADD | INDIROFFADD))) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "relative offset at level 0"); return -1; } /* get offset, then skip over it */ if (*l == '-' || *l == '+') { ++l; /* step over */ m->flag |= l[-1] == '-' ? OFFNEGATIVE : OFFPOSITIVE; } m->offset = CAST(int32_t, strtol(l, &t, 0)); if (l == t) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "offset `%s' invalid", l); return -1; } l = t; if (m->flag & INDIR) { m->in_type = FILE_LONG; m->in_offset = 0; m->in_op = 0; /* * read [.,lbs][+-]nnnnn) */ if (*l == '.' || *l == ',') { if (*l == ',') m->in_op |= FILE_OPSIGNED; 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; case 'e': case 'f': case 'g': m->in_type = FILE_LEDOUBLE; break; case 'E': case 'F': case 'G': m->in_type = FILE_BEDOUBLE; break; case 'i': m->in_type = FILE_LEID3; break; case 'I': m->in_type = FILE_BEID3; break; case 'o': m->in_type = FILE_OCTAL; break; case 'q': m->in_type = FILE_LEQUAD; break; case 'Q': m->in_type = FILE_BEQUAD; break; default: if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "indirect offset type `%c' invalid", *l); return -1; } l++; } if (*l == '~') { m->in_op |= FILE_OPINVERSE; l++; } if ((op = get_op(*l)) != -1) { m->in_op |= op; l++; } if (*l == '(') { m->in_op |= FILE_OPINDIRECT; l++; } if (isdigit(CAST(unsigned char, *l)) || *l == '-') { m->in_offset = CAST(int32_t, strtol(l, &t, 0)); if (l == t) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "in_offset `%s' invalid", l); return -1; } l = t; } if (*l++ != ')' || ((m->in_op & FILE_OPINDIRECT) && *l++ != ')')) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "missing ')' in indirect offset"); return -1; } } EATAB; #ifdef ENABLE_CONDITIONALS m->cond = get_cond(l, &l); if (check_cond(ms, m->cond, cont_level) == -1) return -1; EATAB; #endif /* * Parse the type. */ if (*l == 'u') { /* * Try it as a keyword type prefixed by "u"; match what * follows the "u". If that fails, try it as an SUS * integer type. */ m->type = get_type(type_tbl, l + 1, &l); if (m->type == FILE_INVALID) { /* * Not a keyword type; parse it as an SUS type, * 'u' possibly followed by a number or C/S/L. */ m->type = get_standard_integer_type(l, &l); } /* It's unsigned. */ if (m->type != FILE_INVALID) m->flag |= UNSIGNED; } else { /* * Try it as a keyword type. If that fails, try it as * an SUS integer type if it begins with "d" or as an * SUS string type if it begins with "s". In any case, * it's not unsigned. */ m->type = get_type(type_tbl, l, &l); if (m->type == FILE_INVALID) { /* * Not a keyword type; parse it as an SUS type, * either 'd' possibly followed by a number or * C/S/L, or just 's'. */ if (*l == 'd') m->type = get_standard_integer_type(l, &l); else if (*l == 's' && !isalpha(CAST(unsigned char, l[1]))) { m->type = FILE_STRING; ++l; } } } if (m->type == FILE_INVALID) { /* Not found - try it as a special keyword. */ m->type = get_type(special_tbl, l, &l); } if (m->type == FILE_INVALID) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "type `%s' invalid", l); return -1; } if (m->type == FILE_NAME && cont_level != 0) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "`name%s' entries can only be " "declared at top level", l); return -1; } /* New-style anding: "0 byte&0x80 =0x80 dynamically linked" */ /* New and improved: ~ & | ^ + - * / % -- exciting, isn't it? */ m->mask_op = 0; if (*l == '~') { if (!IS_STRING(m->type)) m->mask_op |= FILE_OPINVERSE; else if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "'~' invalid for string types"); ++l; } m->str_range = 0; m->str_flags = m->type == FILE_PSTRING ? PSTRING_1_LE : 0; if ((op = get_op(*l)) != -1) { if (IS_STRING(m->type)) { int r; if (op != FILE_OPDIVIDE) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "invalid string/indirect op: " "`%c'", *t); return -1; } if (m->type == FILE_INDIRECT) r = parse_indirect_modifier(ms, m, &l); else r = parse_string_modifier(ms, m, &l); if (r == -1) return -1; } else parse_op_modifier(ms, m, &l, op); } /* * 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 '<': m->reln = *l; ++l; if (*l == '=') { if (ms->flags & MAGIC_CHECK) { file_magwarn(ms, "%c= not supported", m->reln); return -1; } ++l; } break; /* 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: m->reln = '='; /* the default relation */ if (*l == 'x' && ((isascii(CAST(unsigned char, l[1])) && isspace(CAST(unsigned char, l[1]))) || !l[1])) { m->reln = *l; ++l; } break; } /* * Grab the value part, except for an 'x' reln. */ if (m->reln != 'x') { if (*l == '\0') { file_magwarn(ms, "incomplete magic `%s'", line); return -1; } if (getvalue(ms, m, &l, action)) return -1; } /* * TODO finish this macro and start using it! * #define offsetcheck {if (offset > ms->bytes_max -1) * magwarn("offset too big"); } */ /* * Now get last part - the description */ EATAB; if (l[0] == '\b') { ++l; m->flag |= NOSPACE; } else if ((l[0] == '\\') && (l[1] == 'b')) { ++l; ++l; m->flag |= NOSPACE; } for (i = 0; i < sizeof(m->desc) && (m->desc[i++] = *l++) != '\0';) continue; if (m->desc[0] == '\0') { // Tuck in the filename for debugging. strlcpy(m->desc + 1, file, sizeof(m->desc) - 1); } if (i == sizeof(m->desc)) { m->desc[sizeof(m->desc) - 1] = '\0'; if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "description `%s' truncated", m->desc); } /* * We only do this check while compiling, or if any of the magic * files were not compiled. */ if (ms->flags & MAGIC_CHECK) { if (check_format(ms, m) == -1) return -1; } #ifndef COMPILE_ONLY if (action == FILE_CHECK) { file_mdump(m); } #endif m->mimetype[0] = '\0'; /* initialise MIME type to none */ return 0; } /* * parse a STRENGTH annotation line from magic file, put into magic[index - 1] * if valid */ /*ARGSUSED*/ file_private int parse_strength(struct magic_set *ms, struct magic_entry *me, const char *line, size_t len __attribute__((__unused__))) { const char *l = line; char *el; unsigned long factor; char sbuf[512]; struct magic *m = &me->mp[0]; if (m->factor_op != FILE_FACTOR_OP_NONE) { file_magwarn(ms, "Current entry already has a strength type: %c %d", m->factor_op, m->factor); return -1; } if (m->type == FILE_NAME) { file_magwarn(ms, "%s: Strength setting is not supported in " "\"name\" magic entries", file_printable(ms, sbuf, sizeof(sbuf), m->value.s, sizeof(m->value.s))); return -1; } EATAB; switch (*l) { case FILE_FACTOR_OP_NONE: break; case FILE_FACTOR_OP_PLUS: case FILE_FACTOR_OP_MINUS: case FILE_FACTOR_OP_TIMES: case FILE_FACTOR_OP_DIV: m->factor_op = *l++; break; default: file_magwarn(ms, "Unknown factor op `%c'", *l); return -1; } EATAB; factor = strtoul(l, &el, 0); if (factor > 255) { file_magwarn(ms, "Too large factor `%lu'", factor); goto out; } if (*el && !isspace(CAST(unsigned char, *el))) { file_magwarn(ms, "Bad factor `%s'", l); goto out; } m->factor = CAST(uint8_t, factor); if (m->factor == 0 && m->factor_op == FILE_FACTOR_OP_DIV) { file_magwarn(ms, "Cannot have factor op `%c' and factor %u", m->factor_op, m->factor); goto out; } return 0; out: m->factor_op = FILE_FACTOR_OP_NONE; m->factor = 0; return -1; } file_private int goodchar(unsigned char x, const char *extra) { return (isascii(x) && isalnum(x)) || strchr(extra, x); } file_private int parse_extra(struct magic_set *ms, struct magic_entry *me, const char *line, size_t llen, off_t off, size_t len, const char *name, const char *extra, int nt) { size_t i; const char *l = line; struct magic *m = &me->mp[me->cont_count == 0 ? 0 : me->cont_count - 1]; char *buf = CAST(char *, CAST(void *, m)) + off; if (buf[0] != '\0') { len = nt ? strlen(buf) : len; file_magwarn(ms, "Current entry already has a %s type " "`%.*s', new type `%s'", name, CAST(int, len), buf, l); return -1; } if (*m->desc == '\0') { file_magwarn(ms, "Current entry does not yet have a " "description for adding a %s type", name); return -1; } EATAB; for (i = 0; *l && i < llen && i < len && goodchar(*l, extra); buf[i++] = *l++) continue; if (i == len && *l) { if (nt) buf[len - 1] = '\0'; if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "%s type `%s' truncated %" SIZE_T_FORMAT "u", name, line, i); } else { if (!isspace(CAST(unsigned char, *l)) && !goodchar(*l, extra)) file_magwarn(ms, "%s type `%s' has bad char '%c'", name, line, *l); if (nt) buf[i] = '\0'; } if (i > 0) return 0; file_magerror(ms, "Bad magic entry '%s'", line); return -1; } /* * Parse an Apple CREATOR/TYPE annotation from magic file and put it into * magic[index - 1] */ file_private int parse_apple(struct magic_set *ms, struct magic_entry *me, const char *line, size_t len) { return parse_extra(ms, me, line, len, CAST(off_t, offsetof(struct magic, apple)), sizeof(me->mp[me->cont_count - 1].apple), "APPLE", "!+-./?", 0); } /* * Parse a comma-separated list of extensions */ file_private int parse_ext(struct magic_set *ms, struct magic_entry *me, const char *line, size_t len) { return parse_extra(ms, me, line, len, CAST(off_t, offsetof(struct magic, ext)), sizeof(me->mp[me->cont_count - 1].ext), "EXTENSION", ",!+-/@?_$&~", 0); /* & for b&w */ /* ~ for journal~ */ } /* * parse a MIME annotation line from magic file, put into magic[index - 1] * if valid */ file_private int parse_mime(struct magic_set *ms, struct magic_entry *me, const char *line, size_t len) { return parse_extra(ms, me, line, len, CAST(off_t, offsetof(struct magic, mimetype)), sizeof(me->mp[me->cont_count - 1].mimetype), "MIME", "+-/.$?:{};=", 1); } file_private int check_format_type(const char *ptr, int type, const char **estr) { int quad = 0, h; size_t len, cnt; if (*ptr == '\0') { /* Missing format string; bad */ *estr = "missing format spec"; return -1; } switch (file_formats[type]) { case FILE_FMT_QUAD: quad = 1; /*FALLTHROUGH*/ case FILE_FMT_NUM: if (quad == 0) { switch (type) { case FILE_BYTE: h = 2; break; case FILE_SHORT: case FILE_BESHORT: case FILE_LESHORT: h = 1; break; case FILE_LONG: case FILE_BELONG: case FILE_LELONG: case FILE_MELONG: case FILE_LEID3: case FILE_BEID3: case FILE_INDIRECT: h = 0; break; default: fprintf(stderr, "Bad number format %d", type); abort(); } } else h = 0; while (*ptr && strchr("+-.#", *ptr) != NULL) ptr++; #define CHECKLEN() do { \ for (len = cnt = 0; isdigit(CAST(unsigned char, *ptr)); ptr++, cnt++) \ len = len * 10 + (*ptr - '0'); \ if (cnt > 5 || len > 1024) \ goto toolong; \ } while (/*CONSTCOND*/0) CHECKLEN(); if (*ptr == '.') ptr++; CHECKLEN(); if (quad) { if (*ptr++ != 'l') goto invalid; if (*ptr++ != 'l') goto invalid; } switch (*ptr++) { #ifdef STRICT_FORMAT /* "long" formats are int formats for us */ /* so don't accept the 'l' modifier */ case 'l': switch (*ptr++) { case 'i': case 'd': case 'u': case 'o': case 'x': case 'X': if (h == 0) return 0; /*FALLTHROUGH*/ default: goto invalid; } /* * Don't accept h and hh modifiers. They make writing * magic entries more complicated, for very little benefit */ case 'h': if (h-- <= 0) goto invalid; switch (*ptr++) { case 'h': if (h-- <= 0) goto invalid; switch (*ptr++) { case 'i': case 'd': case 'u': case 'o': case 'x': case 'X': return 0; default: goto invalid; } case 'i': case 'd': case 'u': case 'o': case 'x': case 'X': if (h == 0) return 0; /*FALLTHROUGH*/ default: goto invalid; } #endif case 'c': if (h == 2) return 0; goto invalid; case 'i': case 'd': case 'u': case 'o': case 'x': case 'X': #ifdef STRICT_FORMAT if (h == 0) return 0; /*FALLTHROUGH*/ #else return 0; #endif default: goto invalid; } case FILE_FMT_FLOAT: case FILE_FMT_DOUBLE: if (*ptr == '-') ptr++; if (*ptr == '.') ptr++; CHECKLEN(); if (*ptr == '.') ptr++; CHECKLEN(); switch (*ptr++) { case 'e': case 'E': case 'f': case 'F': case 'g': case 'G': return 0; default: goto invalid; } case FILE_FMT_STR: if (*ptr == '-') ptr++; while (isdigit(CAST(unsigned char, *ptr))) ptr++; if (*ptr == '.') { ptr++; while (isdigit(CAST(unsigned char , *ptr))) ptr++; } switch (*ptr++) { case 's': return 0; default: goto invalid; } default: /* internal error */ fprintf(stderr, "Bad file format %d", type); abort(); } invalid: *estr = "not valid"; return -1; toolong: *estr = "too long"; return -1; } /* * Check that the optional printf format in description matches * the type of the magic. */ file_private int check_format(struct magic_set *ms, struct magic *m) { char *ptr; const char *estr; for (ptr = m->desc; *ptr; ptr++) if (*ptr == '%') break; if (*ptr == '\0') { /* No format string; ok */ return 1; } assert(file_nformats == file_nnames); if (m->type >= file_nformats) { file_magwarn(ms, "Internal error inconsistency between " "m->type and format strings"); return -1; } if (file_formats[m->type] == FILE_FMT_NONE) { file_magwarn(ms, "No format string for `%s' with description " "`%s'", m->desc, file_names[m->type]); return -1; } ptr++; if (check_format_type(ptr, m->type, &estr) == -1) { /* * TODO: this error message is unhelpful if the format * string is not one character long */ file_magwarn(ms, "Printf format is %s for type " "`%s' in description `%s'", estr, file_names[m->type], m->desc); return -1; } for (; *ptr; ptr++) { if (*ptr == '%') { file_magwarn(ms, "Too many format strings (should have at most one) " "for `%s' with description `%s'", file_names[m->type], m->desc); return -1; } } return 0; } /* * 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. */ file_no_overflow file_private int getvalue(struct magic_set *ms, struct magic *m, const char **p, int action) { char *ep; uint64_t ull; int y; switch (m->type) { case FILE_BESTRING16: case FILE_LESTRING16: case FILE_STRING: case FILE_PSTRING: case FILE_REGEX: case FILE_SEARCH: case FILE_NAME: case FILE_USE: case FILE_DER: case FILE_OCTAL: *p = getstr(ms, m, *p, action == FILE_COMPILE); if (*p == NULL) { if (ms->flags & MAGIC_CHECK) file_magwarn(ms, "cannot get string from `%s'", m->value.s); return -1; } if (m->type == FILE_REGEX) { file_regex_t rx; int rc = file_regcomp(ms, &rx, m->value.s, REG_EXTENDED); if (rc == 0) { file_regfree(&rx); } return rc ? -1 : 0; } return 0; default: if (m->reln == 'x') return 0; break; } switch (m->type) { case FILE_FLOAT: case FILE_BEFLOAT: case FILE_LEFLOAT: errno = 0; #ifdef HAVE_STRTOF m->value.f = strtof(*p, &ep); #else m->value.f = (float)strtod(*p, &ep); #endif if (errno == 0) *p = ep; return 0; case FILE_DOUBLE: case FILE_BEDOUBLE: case FILE_LEDOUBLE: errno = 0; m->value.d = strtod(*p, &ep); if (errno == 0) *p = ep; return 0; case FILE_GUID: if (file_parse_guid(*p, m->value.guid) == -1) { file_magwarn(ms, "Error parsing guid `%s'", *p); return -1; } *p += FILE_GUID_SIZE - 1; return 0; default: errno = 0; ull = CAST(uint64_t, strtoull(*p, &ep, 0)); m->value.q = file_signextend(ms, m, ull); if (*p == ep) { file_magwarn(ms, "Unparsable number `%s'", *p); return -1; } else { size_t ts = typesize(m->type); uint64_t x; const char *q; if (ts == FILE_BADSIZE) { file_magwarn(ms, "Expected numeric type got `%s'", type_tbl[m->type].name); return -1; } for (q = *p; isspace(CAST(unsigned char, *q)); q++) continue; if (*q == '-' && ull != UINT64_MAX) ull = -CAST(int64_t, ull); switch (ts) { case 1: x = CAST(uint64_t, ull & ~0xffULL); y = (x & ~0xffULL) != ~0xffULL; break; case 2: x = CAST(uint64_t, ull & ~0xffffULL); y = (x & ~0xffffULL) != ~0xffffULL; break; case 4: x = CAST(uint64_t, ull & ~0xffffffffULL); y = (x & ~0xffffffffULL) != ~0xffffffffULL; break; case 8: x = 0; y = 0; break; default: fprintf(stderr, "Bad width %zu", ts); abort(); } if (x && y) { file_magwarn(ms, "Overflow for numeric" " type `%s' value %#" PRIx64, type_tbl[m->type].name, ull); return -1; } } if (errno == 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 "m->value.s", and the length in m->vallen. * Return updated scan pointer as function result. Warn if set. */ file_private const char * getstr(struct magic_set *ms, struct magic *m, const char *s, int warn) { const char *origs = s; char *p = m->value.s; size_t plen = sizeof(m->value.s); char *origp = p; char *pmax = p + plen - 1; int c; int val; size_t bracket_nesting = 0; while ((c = *s++) != '\0') { if (isspace(CAST(unsigned char, c))) break; if (p >= pmax) { file_error(ms, 0, "string too long: `%s'", origs); return NULL; } if (c != '\\') { if (c == '[') { bracket_nesting++; } if (c == ']' && bracket_nesting > 0) { bracket_nesting--; } *p++ = CAST(char, c); continue; } switch(c = *s++) { case '\0': if (warn) file_magwarn(ms, "incomplete escape"); s--; goto out; case '.': if (m->type == FILE_REGEX && bracket_nesting == 0 && warn) { file_magwarn(ms, "escaped dot ('.') found, " "use \\\\. instead"); } warn = 0; /* already did */ /*FALLTHROUGH*/ case '\t': if (warn) { file_magwarn(ms, "escaped tab found, use \\\\t instead"); warn = 0; /* already did */ } /*FALLTHROUGH*/ default: if (warn) { if (isprint(CAST(unsigned char, c))) { /* Allow escaping of * ``relations'' */ if (strchr("<>&^=!", c) == NULL && (m->type != FILE_REGEX || strchr("[]().*?^$|{}", c) == NULL)) { file_magwarn(ms, "no " "need to escape " "`%c'", c); } } else { file_magwarn(ms, "unknown escape sequence: " "\\%03o", c); } } /*FALLTHROUGH*/ /* space, perhaps force people to use \040? */ case ' ': #if 0 /* * Other things people escape, but shouldn't need to, * so we disallow them */ case '\'': case '"': case '?': #endif /* Relations */ case '>': case '<': case '&': case '^': case '=': case '!': /* and backslash itself */ case '\\': *p++ = CAST(char, c); break; case 'a': *p++ = '\a'; break; case 'b': *p++ = '\b'; break; case 'f': *p++ = '\f'; break; case 'n': *p++ = '\n'; break; case 'r': *p++ = '\r'; break; case 't': *p++ = '\t'; 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++ = CAST(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++ = CAST(char, val); break; } } --s; out: *p = '\0'; m->vallen = CAST(unsigned char, (p - origp)); if (m->type == FILE_PSTRING) { size_t l = file_pstring_length_size(ms, m); if (l == FILE_BADSIZE) return NULL; m->vallen += CAST(unsigned char, l); } return s; } /* Single hex char to int; -1 if not a hex char. */ file_private int hextoint(int c) { if (!isascii(CAST(unsigned char, c))) return -1; if (isdigit(CAST(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. */ file_protected void file_showstr(FILE *fp, const char *s, size_t len) { char c; for (;;) { if (len == FILE_BADSIZE) { c = *s++; if (c == '\0') break; } else { if (len-- == 0) break; c = *s++; } if (c >= 040 && c <= 0176) /* TODO isprint && !iscntrl */ (void) fputc(c, fp); else { (void) fputc('\\', fp); switch (c) { case '\a': (void) fputc('a', fp); break; case '\b': (void) fputc('b', fp); break; case '\f': (void) fputc('f', fp); break; case '\n': (void) fputc('n', fp); break; case '\r': (void) fputc('r', fp); break; case '\t': (void) fputc('t', 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] */ file_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 buffer containing a compiled file. */ file_private struct magic_map * apprentice_buf(struct magic_set *ms, struct magic *buf, size_t len) { struct magic_map *map; if ((map = CAST(struct magic_map *, calloc(1, sizeof(*map)))) == NULL) { file_oomem(ms, sizeof(*map)); return NULL; } map->len = len; map->p = buf; map->type = MAP_TYPE_USER; if (check_buffer(ms, map, "buffer") != 0) { apprentice_unmap(map); return NULL; } return map; } /* * handle a compiled file. */ file_private struct magic_map * apprentice_map(struct magic_set *ms, const char *fn) { int fd; struct stat st; char *dbname = NULL; struct magic_map *map; struct magic_map *rv = NULL; fd = -1; if ((map = CAST(struct magic_map *, calloc(1, sizeof(*map)))) == NULL) { file_oomem(ms, sizeof(*map)); goto error; } map->type = MAP_TYPE_USER; /* unspecified */ dbname = mkdbname(ms, fn, 0); if (dbname == NULL) goto error; if ((fd = open(dbname, O_RDONLY|O_BINARY)) == -1) goto error; if (fstat(fd, &st) == -1) { file_error(ms, errno, "cannot stat `%s'", dbname); goto error; } if (st.st_size < 8 || st.st_size > maxoff_t()) { file_error(ms, 0, "file `%s' is too %s", dbname, st.st_size < 8 ? "small" : "large"); goto error; } map->len = CAST(size_t, st.st_size); #ifdef QUICK map->type = MAP_TYPE_MMAP; if ((map->p = mmap(0, CAST(size_t, st.st_size), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FILE, fd, CAST(off_t, 0))) == MAP_FAILED) { file_error(ms, errno, "cannot map `%s'", dbname); goto error; } #else map->type = MAP_TYPE_MALLOC; if ((map->p = CAST(void *, malloc(map->len))) == NULL) { file_oomem(ms, map->len); goto error; } if (read(fd, map->p, map->len) != (ssize_t)map->len) { file_badread(ms); goto error; } #endif (void)close(fd); fd = -1; if (check_buffer(ms, map, dbname) != 0) { goto error; } #ifdef QUICK if (mprotect(map->p, CAST(size_t, st.st_size), PROT_READ) == -1) { file_error(ms, errno, "cannot mprotect `%s'", dbname); goto error; } #endif free(dbname); return map; error: if (fd != -1) (void)close(fd); apprentice_unmap(map); free(dbname); return rv; } file_private int check_buffer(struct magic_set *ms, struct magic_map *map, const char *dbname) { uint32_t *ptr; uint32_t entries, nentries; uint32_t version; int i, needsbyteswap; entries = CAST(uint32_t, map->len / sizeof(struct magic)); if (entries < MAGIC_SETS) { file_error(ms, 0, "Too few magic entries %u in `%s'", entries, dbname); return -1; } if ((entries * sizeof(struct magic)) != map->len) { file_error(ms, 0, "Size of `%s' %" SIZE_T_FORMAT "u is not " "a multiple of %" SIZE_T_FORMAT "u", dbname, map->len, sizeof(struct magic)); return -1; } ptr = CAST(uint32_t *, map->p); if (*ptr != MAGICNO) { if (swap4(*ptr) != MAGICNO) { file_error(ms, 0, "bad magic in `%s'", dbname); return -1; } needsbyteswap = 1; } else needsbyteswap = 0; if (needsbyteswap) version = swap4(ptr[1]); else version = ptr[1]; if (version != VERSIONNO) { file_error(ms, 0, "File %s supports only version %d magic " "files. `%s' is version %d", VERSION, VERSIONNO, dbname, version); return -1; } map->magic[0] = CAST(struct magic *, map->p) + 1; nentries = 0; for (i = 0; i < MAGIC_SETS; i++) { if (needsbyteswap) map->nmagic[i] = swap4(ptr[i + 2]); else map->nmagic[i] = ptr[i + 2]; if (i != MAGIC_SETS - 1) map->magic[i + 1] = map->magic[i] + map->nmagic[i]; nentries += map->nmagic[i]; } if (entries != nentries + 1) { file_error(ms, 0, "Inconsistent entries in `%s' %u != %u", dbname, entries, nentries + 1); return -1; } if (needsbyteswap) for (i = 0; i < MAGIC_SETS; i++) byteswap(map->magic[i], map->nmagic[i]); return 0; } /* * handle an mmaped file. */ file_private int apprentice_compile(struct magic_set *ms, struct magic_map *map, const char *fn) { static const size_t nm = sizeof(*map->nmagic) * MAGIC_SETS; static const size_t m = sizeof(**map->magic); int fd = -1; size_t len; char *dbname; int rv = -1; uint32_t i; union { struct magic m; uint32_t h[2 + MAGIC_SETS]; } hdr; dbname = mkdbname(ms, fn, 1); if (dbname == NULL) goto out; if ((fd = open(dbname, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644)) == -1) { file_error(ms, errno, "cannot open `%s'", dbname); goto out; } memset(&hdr, 0, sizeof(hdr)); hdr.h[0] = MAGICNO; hdr.h[1] = VERSIONNO; memcpy(hdr.h + 2, map->nmagic, nm); if (write(fd, &hdr, sizeof(hdr)) != CAST(ssize_t, sizeof(hdr))) { file_error(ms, errno, "error writing `%s'", dbname); goto out2; } for (i = 0; i < MAGIC_SETS; i++) { len = m * map->nmagic[i]; if (write(fd, map->magic[i], len) != CAST(ssize_t, len)) { file_error(ms, errno, "error writing `%s'", dbname); goto out2; } } rv = 0; out2: if (fd != -1) (void)close(fd); out: apprentice_unmap(map); free(dbname); return rv; } file_private const char ext[] = ".mgc"; /* * make a dbname */ file_private char * mkdbname(struct magic_set *ms, const char *fn, int strip) { const char *p, *q; char *buf; if (strip) { if ((p = strrchr(fn, '/')) != NULL) fn = ++p; } for (q = fn; *q; q++) continue; /* Look for .mgc */ for (p = ext + sizeof(ext) - 1; p >= ext && q >= fn; p--, q--) if (*p != *q) break; /* Did not find .mgc, restore q */ if (p >= ext) for (q = fn; *q; q++) continue; q++; /* Compatibility with old code that looked in .mime */ if (ms->flags & MAGIC_MIME) { if (asprintf(&buf, "%.*s.mime%s", CAST(int, q - fn), fn, ext) < 0) return NULL; if (access(buf, R_OK) != -1) { ms->flags &= MAGIC_MIME_TYPE; return buf; } free(buf); } if (asprintf(&buf, "%.*s%s", CAST(int, q - fn), fn, ext) < 0) return NULL; /* Compatibility with old code that looked in .mime */ if (strstr(fn, ".mime") != NULL) ms->flags &= MAGIC_MIME_TYPE; return buf; } /* * Byteswap an mmap'ed file if needed */ file_private void byteswap(struct magic *magic, uint32_t nmagic) { uint32_t i; for (i = 0; i < nmagic; i++) bs1(&magic[i]); } #if !defined(HAVE_BYTESWAP_H) && !defined(HAVE_SYS_BSWAP_H) /* * swap a short */ file_private uint16_t swap2(uint16_t sv) { uint16_t rv; uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); d[0] = s[1]; d[1] = s[0]; return rv; } /* * swap an int */ file_private uint32_t swap4(uint32_t sv) { uint32_t rv; uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); d[0] = s[3]; d[1] = s[2]; d[2] = s[1]; d[3] = s[0]; return rv; } /* * swap a quad */ file_private uint64_t swap8(uint64_t sv) { uint64_t rv; uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); # if 0 d[0] = s[3]; d[1] = s[2]; d[2] = s[1]; d[3] = s[0]; d[4] = s[7]; d[5] = s[6]; d[6] = s[5]; d[7] = s[4]; # else d[0] = s[7]; d[1] = s[6]; d[2] = s[5]; d[3] = s[4]; d[4] = s[3]; d[5] = s[2]; d[6] = s[1]; d[7] = s[0]; # endif return rv; } #endif file_protected uintmax_t file_varint2uintmax_t(const unsigned char *us, int t, size_t *l) { uintmax_t x = 0; const unsigned char *c; if (t == FILE_LEVARINT) { for (c = us; *c; c++) { if ((*c & 0x80) == 0) break; } if (l) *l = c - us + 1; for (; c >= us; c--) { x |= *c & 0x7f; x <<= 7; } } else { for (c = us; *c; c++) { x |= *c & 0x7f; if ((*c & 0x80) == 0) break; x <<= 7; } if (l) *l = c - us + 1; } return x; } /* * byteswap a single magic entry */ file_private void bs1(struct magic *m) { m->flag = swap2(m->flag); m->offset = swap4(CAST(uint32_t, m->offset)); m->in_offset = swap4(CAST(uint32_t, m->in_offset)); m->lineno = swap4(CAST(uint32_t, m->lineno)); if (IS_STRING(m->type)) { m->str_range = swap4(m->str_range); m->str_flags = swap4(m->str_flags); } else { m->value.q = swap8(m->value.q); m->num_mask = swap8(m->num_mask); } } file_protected size_t file_pstring_length_size(struct magic_set *ms, const struct magic *m) { switch (m->str_flags & PSTRING_LEN) { case PSTRING_1_LE: return 1; case PSTRING_2_LE: case PSTRING_2_BE: return 2; case PSTRING_4_LE: case PSTRING_4_BE: return 4; default: file_error(ms, 0, "corrupt magic file " "(bad pascal string length %d)", m->str_flags & PSTRING_LEN); return FILE_BADSIZE; } } file_protected size_t file_pstring_get_length(struct magic_set *ms, const struct magic *m, const char *ss) { size_t len = 0; const unsigned char *s = RCAST(const unsigned char *, ss); unsigned int s3, s2, s1, s0; switch (m->str_flags & PSTRING_LEN) { case PSTRING_1_LE: len = *s; break; case PSTRING_2_LE: s0 = s[0]; s1 = s[1]; len = (s1 << 8) | s0; break; case PSTRING_2_BE: s0 = s[0]; s1 = s[1]; len = (s0 << 8) | s1; break; case PSTRING_4_LE: s0 = s[0]; s1 = s[1]; s2 = s[2]; s3 = s[3]; len = (s3 << 24) | (s2 << 16) | (s1 << 8) | s0; break; case PSTRING_4_BE: s0 = s[0]; s1 = s[1]; s2 = s[2]; s3 = s[3]; len = (s0 << 24) | (s1 << 16) | (s2 << 8) | s3; break; default: file_error(ms, 0, "corrupt magic file " "(bad pascal string length %d)", m->str_flags & PSTRING_LEN); return FILE_BADSIZE; } if (m->str_flags & PSTRING_LENGTH_INCLUDES_ITSELF) { size_t l = file_pstring_length_size(ms, m); if (l == FILE_BADSIZE) return l; len -= l; } return len; } file_protected int file_magicfind(struct magic_set *ms, const char *name, struct mlist *v) { uint32_t i, j; struct mlist *mlist, *ml; mlist = ms->mlist[1]; for (ml = mlist->next; ml != mlist; ml = ml->next) { struct magic *ma = ml->magic; for (i = 0; i < ml->nmagic; i++) { if (ma[i].type != FILE_NAME) continue; if (strcmp(ma[i].value.s, name) == 0) { v->magic = &ma[i]; v->magic_rxcomp = &(ml->magic_rxcomp[i]); for (j = i + 1; j < ml->nmagic; j++) if (ma[j].cont_level == 0) break; v->nmagic = j - i; return 0; } } } return -1; }