示例#1
0
/*
 * parse one line from magic file, put into magic[index++] if valid
 */
static int parse(RMagic *ms, struct r_magic_entry **mentryp, ut32 *nmentryp, const char *line, size_t lineno, int action) {
	static ut32 last_cont_level = 0;
	size_t i;
	struct r_magic_entry *me;
	struct r_magic *m;
	const char *l = line;
	char *t;
	int op;
	ut32 cont_level = 0;

	for (; *l == '>'; l++, cont_level++);
	if (cont_level == 0 || cont_level > last_cont_level)
		if (file_check_mem (ms, cont_level) == -1)
			return -1;
	last_cont_level = 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 r_magic *nm;
			size_t cnt = me->max_count + ALLOC_CHUNK;
			if (!(nm = realloc(me->mp, sizeof (*nm) * cnt))) {
				file_oomem(ms, sizeof (*nm) * cnt);
				return -1;
			}
			me->mp = nm;
			me->max_count = cnt;
		}
		m = &me->mp[me->cont_count++];
		(void)memset(m, 0, sizeof (*m));
		m->cont_level = cont_level;
	} else {
		if (*nmentryp == maxmagic) {
			struct r_magic_entry *mp;

			maxmagic += ALLOC_INCR;
			if (!(mp = realloc (*mentryp, sizeof (*mp) * maxmagic))) {
				file_oomem (ms, sizeof (*mp) * maxmagic);
				return -1;
			}
			(void)memset(&mp[*nmentryp], 0, sizeof (*mp) *
			    ALLOC_INCR);
			*mentryp = mp;
		}
		me = &(*mentryp)[*nmentryp];
		if (!me->mp) {
			if (!(m = malloc (sizeof (*m) * ALLOC_CHUNK))) {
				file_oomem (ms, sizeof (*m) * ALLOC_CHUNK);
				return -1;
			}
			me->mp = m;
			me->max_count = ALLOC_CHUNK;
		} else
			m = me->mp;
		(void)memset(m, 0, sizeof (*m));
		m->cont_level = 0;
		me->cont_count = 1;
	}
	m->lineno = 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 & R_MAGIC_CHECK)
			file_magwarn(ms, "relative offset at level 0");

	/* get offset, then skip over it */
	m->offset = (ut32)strtoul(l, &t, 0);
        if ((l == t) && (ms->flags & R_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;
			case 'e':
			case 'f':
			case 'g':
				m->in_type = FILE_LEDOUBLE;
				break;
			case 'E':
			case 'F':
			case 'G':
				m->in_type = FILE_BEDOUBLE;
				break;
			default:
				if (ms->flags & R_MAGIC_CHECK)
					file_magwarn(ms,
					    "indirect offset type `%c' invalid",
					    *l);
				break;
			}
			l++;
		}

		m->in_op = 0;
		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((ut8)*l) || *l == '-') {
			m->in_offset = (int32_t)strtol(l, &t, 0);
			if (l == t)
				if (ms->flags & R_MAGIC_CHECK)
					file_magwarn(ms,
					    "in_offset `%s' invalid", l);
			l = t;
		}
		if (*l++ != ')' ||
		    ((m->in_op & FILE_OPINDIRECT) && *l++ != ')'))
			if (ms->flags & R_MAGIC_CHECK)
				file_magwarn(ms,
				    "missing ')' in indirect offset");
	}
	EATAB;

	m->cond = get_cond(l, &l);
	if (check_cond(ms, m->cond, cont_level) == -1)
		return -1;
	EATAB;

	if (*l == 'u') {
		++l;
		m->flag |= UNSIGNED;
	}

	m->type = get_type(l, &l);
	if (m->type == FILE_INVALID) {
		if (ms->flags & R_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? */

	m->mask_op = 0;
	if (*l == '~') {
		if (!MAGIC_IS_STRING (m->type))
			m->mask_op |= FILE_OPINVERSE;
		else if (ms->flags & R_MAGIC_CHECK)
			file_magwarn (ms, "'~' invalid for string types");
		++l;
	}
	m->str_range = 0;
	m->str_flags = 0;
	m->num_mask = 0;
	if ((op = get_op (*l)) != -1) {
		if (!MAGIC_IS_STRING (m->type)) {
			ut64 val;
			++l;
			m->mask_op |= op;
			val = (ut64)strtoull (l, &t, 0);
			l = t;
			m->num_mask = file_signextend (ms, m, val);
			eatsize (&l);
		}
		else if (op == FILE_OPDIVIDE) {
			int have_range = 0;
			while (!isspace ((ut8)*++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 & R_MAGIC_CHECK))
						file_magwarn(ms,
						    "multiple ranges");
					have_range = 1;
					m->str_range = strtoul(l, &t, 0);
					if (m->str_range == 0)
						file_magwarn(ms,
						    "zero range");
					l = t - 1;
					break;
				case CHAR_COMPACT_BLANK:
					m->str_flags |= STRING_COMPACT_BLANK;
					break;
				case CHAR_COMPACT_OPTIONAL_BLANK:
					m->str_flags |=
					    STRING_COMPACT_OPTIONAL_BLANK;
					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;
				default:
					if (ms->flags & R_MAGIC_CHECK)
						file_magwarn(ms,
						"string extension `%c' invalid",
						*l);
					return -1;
				}
				/* allow multiple '/' for readability */
				if (l[1] == '/' && !isspace ((ut8)l[2]))
					l++;
			}
			if (string_modifier_check(ms, m) == -1)
				return -1;
		} else {
			if (ms->flags & R_MAGIC_CHECK)
				file_magwarn(ms, "invalid string op: %c", *t);
			return -1;
		}
	}
	/*
	 * 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:
  		m->reln = '=';	/* the default relation */
		if (*l == 'x' && ((isascii((ut8)l[1]) &&
				isspace ((ut8)l[1])) || !l[1])) {
			m->reln = *l;
			++l;
		}
		break;
	}
	/*
	 * Grab the value part, except for an 'x' reln.
	 */
	if (m->reln != 'x' && getvalue (ms, m, &l, action))
		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
	 */
	EATAB;
	if (l[0] == '\b') {
		++l;
		m->flag |= NOSPACE;
	} else if ((l[0] == '\\') && (l[1] == 'b')) {
		++l;
		++l;
		m->flag |= NOSPACE;
	}
	for (i = 0; (m->desc[i++] = *l++) != '\0' && i < sizeof (m->desc); )
		continue;
	if (i == sizeof (m->desc)) {
		m->desc[sizeof (m->desc) - 1] = '\0';
		if (ms->flags & R_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 & R_MAGIC_CHECK)
		if (check_format (ms, m) == -1)
			return -1;
	if (action == FILE_CHECK)
		file_mdump (m);
	m->mimetype[0] = '\0';		/* initialise MIME type to none */
	if (m->cont_level == 0)
		++(*nmentryp);		/* make room for next */
	return 0;
}
示例#2
0
/*
 * Go through the whole list, stopping if you find a match.  Process all
 * the continuations of that match before returning.
 *
 * We support multi-level continuations:
 *
 *	At any time when processing a successful top-level match, there is a
 *	current continuation level; it represents the level of the last
 *	successfully matched continuation.
 *
 *	Continuations above that level are skipped as, if we see one, it
 *	means that the continuation that controls them - i.e, the
 *	lower-level continuation preceding them - failed to match.
 *
 *	Continuations below that level are processed as, if we see one,
 *	it means we've finished processing or skipping higher-level
 *	continuations under the control of a successful or unsuccessful
 *	lower-level continuation, and are now seeing the next lower-level
 *	continuation and should process it.  The current continuation
 *	level reverts to the level of the one we're seeing.
 *
 *	Continuations at the current level are processed as, if we see
 *	one, there's no lower-level continuation that may have failed.
 *
 *	If a continuation matches, we bump the current continuation level
 *	so that higher-level continuations are processed.
 */
static int match(RMagic *ms, struct r_magic *magic, ut32 nmagic, const ut8 *s, size_t nbytes, int mode) {
    ut32 magindex = 0;
    unsigned int cont_level = 0;
    int need_separator = 0;
    int returnval = 0; /* if a match is found it is set to 1*/
    int firstline = 1; /* a flag to print X\n  X\n- X */
    int printed_something = 0;

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

    for (magindex = 0; magindex < nmagic; magindex++) {
        int flush;
        struct r_magic *m = &magic[magindex];

        if ((m->flag & BINTEST) != mode) {
            /* Skip sub-tests */
            while (magic[magindex + 1].cont_level != 0 &&
                    ++magindex < nmagic - 1)
                continue;
            continue; /* Skip to next top-level test*/
        }

        ms->offset = m->offset;
        ms->line = m->lineno;

        /* if main entry matches, print it... */
        flush = !mget(ms, s, m, nbytes, cont_level);
        if (flush) {
            if (m->reln == '!')
                flush = 0;
        } else {
            int ret = magiccheck (ms, m);
            if (ret == -1) return -1;
            if (!ret) flush++;
        }
        if (flush) {
            /*
             * main entry didn't match,
             * flush its continuations
             */
            while (magindex < nmagic - 1 && magic[magindex + 1].cont_level)
                magindex++;
            continue;
        }

        /*
         * If we are going to print something, we'll need to print
         * a blank before we print something else.
         */
        if (*R_MAGIC_DESC) {
            need_separator = 1;
            printed_something = 1;
            if (print_sep(ms, firstline) == -1)
                return -1;
        }

        if ((ms->c.li[cont_level].off = mprint(ms, m)) == -1)
            return -1;

        /* and any continuations that match */
        if (file_check_mem(ms, ++cont_level) == -1)
            return -1;

        while (++magindex < nmagic - 1 && magic[magindex].cont_level != 0) {
            m = &magic[magindex];
            ms->line = m->lineno; /* for messages */

            if (cont_level < m->cont_level)
                continue;
            if (cont_level > m->cont_level) {
                /*
                 * We're at the end of the level
                 * "cont_level" continuations.
                 */
                cont_level = m->cont_level;
            }
            ms->offset = m->offset;
            if (m->flag & OFFADD)
                ms->offset += ms->c.li[cont_level - 1].off;

            if (m->cond == COND_ELSE || m->cond == COND_ELIF) {
                if (ms->c.li[cont_level].last_match == 1)
                    continue;
            }
            flush = !mget(ms, s, m, nbytes, cont_level);
            if (flush && m->reln != '!')
                continue;

            switch (flush ? 1 : magiccheck(ms, m)) {
            case -1:
                return -1;
            case 0:
                ms->c.li[cont_level].last_match = 0;
                break;
            default:
                ms->c.li[cont_level].last_match = 1;
                if (m->type != FILE_DEFAULT)
                    ms->c.li[cont_level].got_match = 1;
                else if (ms->c.li[cont_level].got_match) {
                    ms->c.li[cont_level].got_match = 0;
                    break;
                }
                /*
                 * If we are going to print something,
                 * make sure that we have a separator first.
                 */
                if (*R_MAGIC_DESC) {
                    printed_something = 1;
                    if (print_sep(ms, firstline) == -1)
                        return -1;
                }
                /*
                 * This continuation matched.  Print
                 * its message, with a blank before it
                 * if the previous item printed and
                 * this item isn't empty.
                 */
                /* space if previous printed */
                if (need_separator
                        && ((m->flag & NOSPACE) == 0)
                        && *R_MAGIC_DESC) {
                    if (file_printf (ms, " ") == -1)
                        return -1;
                    need_separator = 0;
                }
                if ((ms->c.li[cont_level].off = mprint(ms, m)) == -1)
                    return -1;
                if (*R_MAGIC_DESC)
                    need_separator = 1;

                /*
                 * If we see any continuations
                 * at a higher level,
                 * process them.
                 */
                if (file_check_mem(ms, ++cont_level) == -1)
                    return -1;
                break;
            }
        }
        if (printed_something) {
            firstline = 0;
            returnval = 1;
        }
        if ((ms->flags & R_MAGIC_CONTINUE) == 0 && printed_something)
            return 1; /* don't keep searching */
    }
    return returnval;  /* This is hit if -k is set or there is no match */
}