mod_mime_magic.c

apache简化版

	    ++errs;
    }

    (void) ap_pfclose(p, f);

#if MIME_MAGIC_DEBUG
    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, s,
		MODNAME ": apprentice conf=%x file=%s m=%s m->next=%s last=%s",
		conf,
		conf->magicfile ? conf->magicfile : "NULL",
		conf->magic ? "set" : "NULL",
		(conf->magic && conf->magic->next) ? "set" : "NULL",
		conf->last ? "set" : "NULL");
    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, s,
		MODNAME ": apprentice read %d lines, %d rules, %d errors",
		lineno, rule, errs);
#endif

#if MIME_MAGIC_DEBUG
    prevm = 0;
    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, s,
		MODNAME ": apprentice test");
    for (m = conf->magic; m; m = m->next) {
	if (ap_isprint((((unsigned long) m) >> 24) & 255) &&
	    ap_isprint((((unsigned long) m) >> 16) & 255) &&
	    ap_isprint((((unsigned long) m) >> 8) & 255) &&
	    ap_isprint(((unsigned long) m) & 255)) {
	    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, s,
			MODNAME ": apprentice: POINTER CLOBBERED! "
			"m=\"%c%c%c%c\" line=%d",
			(((unsigned long) m) >> 24) & 255,
			(((unsigned long) m) >> 16) & 255,
			(((unsigned long) m) >> 8) & 255,
			((unsigned long) m) & 255,
			prevm ? prevm->lineno : -1);
	    break;
	}
	prevm = m;
    }
#endif

    return (errs ? -1 : 0);
}

/*
 * extend the sign bit if the comparison is to be signed
 */
static unsigned long signextend(server_rec *s, struct magic *m, unsigned long 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 BYTE:
	    v = (char) v;
	    break;
	case SHORT:
	case BESHORT:
	case LESHORT:
	    v = (short) v;
	    break;
	case DATE:
	case BEDATE:
	case LEDATE:
	case LONG:
	case BELONG:
	case LELONG:
	    v = (long) v;
	    break;
	case STRING:
	    break;
	default:
	    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, s,
			MODNAME ": can't happen: m->type=%d", m->type);
	    return -1;
	}
    return v;
}

/*
 * parse one line from magic file, put into magic[index++] if valid
 */
static int parse(server_rec *serv, pool *p, char *l, int lineno)
{
    struct magic *m;
    char *t, *s;
    magic_server_config_rec *conf = (magic_server_config_rec *)
		    ap_get_module_config(serv->module_config, &mime_magic_module);

    /* allocate magic structure entry */
    m = (struct magic *) ap_pcalloc(p, sizeof(struct magic));

    /* append to linked list */
    m->next = NULL;
    if (!conf->magic || !conf->last) {
	conf->magic = conf->last = m;
    }
    else {
	conf->last->next = m;
	conf->last = m;
    }

    /* set values in magic structure */
    m->flag = 0;
    m->cont_level = 0;
    m->lineno = lineno;

    while (*l == '>') {
	++l;			/* step over */
	m->cont_level++;
    }

    if (m->cont_level != 0 && *l == '(') {
	++l;			/* step over */
	m->flag |= INDIR;
    }

    /* get offset, then skip over it */
    m->offset = (int) strtol(l, &t, 0);
    if (l == t) {
	ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, serv,
		    MODNAME ": offset %s invalid", l);
    }
    l = t;

    if (m->flag & INDIR) {
	m->in.type = LONG;
	m->in.offset = 0;
	/*
	 * read [.lbs][+-]nnnnn)
	 */
	if (*l == '.') {
	    switch (*++l) {
	    case 'l':
		m->in.type = LONG;
		break;
	    case 's':
		m->in.type = SHORT;
		break;
	    case 'b':
		m->in.type = BYTE;
		break;
	    default:
		ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, serv,
			MODNAME ": indirect offset type %c invalid", *l);
		break;
	    }
	    l++;
	}
	s = l;
	if (*l == '+' || *l == '-')
	    l++;
	if (ap_isdigit((unsigned char) *l)) {
	    m->in.offset = strtol(l, &t, 0);
	    if (*s == '-')
		m->in.offset = -m->in.offset;
	}
	else
	    t = l;
	if (*t++ != ')') {
	    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, serv,
			MODNAME ": missing ')' in indirect offset");
	}
	l = t;
    }


    while (ap_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 NLEDATE         6

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

    /* get type, skip it */
    if (strncmp(l, "byte", NBYTE) == 0) {
	m->type = BYTE;
	l += NBYTE;
    }
    else if (strncmp(l, "short", NSHORT) == 0) {
	m->type = SHORT;
	l += NSHORT;
    }
    else if (strncmp(l, "long", NLONG) == 0) {
	m->type = LONG;
	l += NLONG;
    }
    else if (strncmp(l, "string", NSTRING) == 0) {
	m->type = STRING;
	l += NSTRING;
    }
    else if (strncmp(l, "date", NDATE) == 0) {
	m->type = DATE;
	l += NDATE;
    }
    else if (strncmp(l, "beshort", NBESHORT) == 0) {
	m->type = BESHORT;
	l += NBESHORT;
    }
    else if (strncmp(l, "belong", NBELONG) == 0) {
	m->type = BELONG;
	l += NBELONG;
    }
    else if (strncmp(l, "bedate", NBEDATE) == 0) {
	m->type = BEDATE;
	l += NBEDATE;
    }
    else if (strncmp(l, "leshort", NLESHORT) == 0) {
	m->type = LESHORT;
	l += NLESHORT;
    }
    else if (strncmp(l, "lelong", NLELONG) == 0) {
	m->type = LELONG;
	l += NLELONG;
    }
    else if (strncmp(l, "ledate", NLEDATE) == 0) {
	m->type = LEDATE;
	l += NLEDATE;
    }
    else {
	ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, serv,
		    MODNAME ": type %s invalid", l);
	return -1;
    }
    /* New-style anding: "0 byte&0x80 =0x80 dynamically linked" */
    if (*l == '&') {
	++l;
	m->mask = signextend(serv, m, strtol(l, &l, 0));
    }
    else
	m->mask = ~0L;
    EATAB;

    switch (*l) {
    case '>':
    case '<':
	/* Old-style anding: "0 byte &0x80 dynamically linked" */
    case '&':
    case '^':
    case '=':
	m->reln = *l;
	++l;
	break;
    case '!':
	if (m->type != STRING) {
	    m->reln = *l;
	    ++l;
	    break;
	}
	/* FALL THROUGH */
    default:
	if (*l == 'x' && ap_isspace((unsigned char) l[1])) {
	    m->reln = *l;
	    ++l;
	    goto GetDesc;	/* Bill The Cat */
	}
	m->reln = '=';
	break;
    }
    EATAB;

    if (getvalue(serv, m, &l))
	return -1;
    /*
     * 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;
    strncpy(m->desc, l, sizeof(m->desc) - 1);
    m->desc[sizeof(m->desc) - 1] = '\0';

#if MIME_MAGIC_DEBUG
    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, serv,
		MODNAME ": parse line=%d m=%x next=%x cont=%d desc=%s",
		lineno, m, m->next, m->cont_level, m->desc);
#endif /* MIME_MAGIC_DEBUG */

    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.
 */
static int getvalue(server_rec *s, struct magic *m, char **p)
{
    int slen;

    if (m->type == STRING) {
	*p = getstr(s, *p, m->value.s, sizeof(m->value.s), &slen);
	m->vallen = slen;
    }
    else if (m->reln != 'x')
	m->value.l = signextend(s, m, strtol(*p, p, 0));
    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.
 */
static char *getstr(server_rec *serv, register char *s, register char *p,
		    int plen, int *slen)
{
    char *origs = s, *origp = p;
    char *pmax = p + plen - 1;
    register int c;
    register int val;

    while ((c = *s++) != '\0') {
	if (ap_isspace((unsigned char) c))
	    break;
	if (p >= pmax) {
	    ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, serv,
			MODNAME ": string too long: %s", origs);
	    break;
	}
	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 3 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;
			c = hextoint(*s++);
			if (c >= 0) {
			    val = (val << 4) + c;
			}
			else
			    --s;
		    }
		    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. */
static int hextoint(int c)
{
    if (ap_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;
}


/*
 * return DONE to indicate it's been handled
 * return OK to indicate it's a regular file still needing handling
 * other returns indicate a failure of some sort
 */
static int fsmagic(request_rec *r, const char *fn)
{
    switch (r->finfo.st_mode & S_IFMT) {
    case S_IFDIR:
	magic_rsl_puts(r, DIR_MAGIC_TYPE);
	return DONE;
    case S_IFCHR:
	/*
	 * (void) magic_rsl_printf(r,"character special (%d/%d)",
	 * major(sb->st_rdev), minor(sb->st_rdev));
	 */
	(void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
	return DONE;
#ifdef S_IFBLK
    case S_IFBLK:
	/*
	 * (void) magic_rsl_printf(r,"block special (%d/%d)",
	 * major(sb->st_rdev), minor(sb->st_rdev));
	 */
	(void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
	return DONE;
	/* TODO add code to handle V7 MUX and Blit MUX files */
#endif
#ifdef    S_IFIFO
    case S_IFIFO:
	/*
	 * magic_rsl_puts(r,"fifo (named pipe)");
	 */
	(void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
	return DONE;
#endif
#ifdef    S_IFLNK
    case S_IFLNK:
	/* We used stat(), the only possible reason for this is that the
	 * symlink is broken.
	 */
	ap_log_rerror(APLOG_MARK, APLOG_NOERRNO | APLOG_ERR, r,