mime_magic.c

php-4.4.7学习linux时下载的源代码

static long from_oct(int digs, char *where)
{
    register long value;

    while (isspace(*where)) {	/* Skip spaces */
		where++;
		if (--digs <= 0)
			return -1;		/* All blank field */
    }
    value = 0;
    while (digs > 0 && isodigit(*where)) {	/* Scan til nonoctal */
		value = (value << 3) | (*where++ - '0');
		--digs;
    }

    if (digs > 0 && *where && !isspace(*where))
		return -1;		/* Ended on non-space/nul */

    return value;
}

static int mget(union VALUETYPE *p, unsigned char *s,
				struct magic *m, int nbytes)
{
    long offset = m->offset;

    if (offset + sizeof(union VALUETYPE) > nbytes)
		return 0;

    memcpy(p, s + offset, sizeof(union VALUETYPE));

    if (!mconvert(p, m))
		return 0;

    if (m->flag & INDIR) {

		switch (m->in.type) {
		case BYTE:
			offset = p->b + m->in.offset;
			break;
		case SHORT:
			offset = p->h + m->in.offset;
			break;
		case LONG:
			offset = p->l + m->in.offset;
			break;
		}

		if (offset + sizeof(union VALUETYPE) > nbytes)
			return 0;

		memcpy(p, s + offset, sizeof(union VALUETYPE));

		if (!mconvert(p, m))
			return 0;
    }
    return 1;
}

static int mcheck(union VALUETYPE *p, struct magic *m)
{
    register unsigned long l = m->value.l;
    register unsigned long v;
    int matched;

    if ((m->value.s[0] == 'x') && (m->value.s[1] == '\0')) {
		php_error(E_WARNING,
					  MODNAME ": BOINK");
		return 1;
    }

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

    case SHORT:
    case BESHORT:
    case LESHORT:
		v = p->h;
		break;

    case LONG:
    case BELONG:
    case LELONG:
    case DATE:
    case BEDATE:
    case LEDATE:
		v = p->l;
		break;

    case STRING:
		l = 0;
		/*
		 * What we want here is: v = strncmp(m->value.s, p->s, m->vallen);
		 * but ignoring any nulls.  bcmp doesn't give -/+/0 and isn't
		 * universally available anyway.
		 */
		v = 0;
		{
			register unsigned char *a = (unsigned char *) m->value.s;
			register unsigned char *b = (unsigned char *) p->s;
			register int len = m->vallen;

			while (--len >= 0)
				if ((v = *b++ - *a++) != 0)
					break;
		}
		break;
    default:
		/*  bogosity, pretend that it just wasn't a match */
		php_error(E_WARNING,
					  MODNAME ": invalid type %d in mcheck().", m->type);
		return 0;
    }

    v = signextend(m, v) & m->mask;

    switch (m->reln) {
    case 'x':
		matched = 1;
		break;

    case '!':
		matched = v != l;
		break;

    case '=':
		matched = v == l;
		break;

    case '>':
		if (m->flag & UNSIGNED) {
			matched = v > l;
		}
		else {
			matched = (long) v > (long) l;
		}
		break;

    case '<':
		if (m->flag & UNSIGNED) {
			matched = v < l;
		}
		else {
			matched = (long) v < (long) l;
		}
		break;

    case '&':
		matched = (v & l) == l;
		break;

    case '^':
		matched = (v & l) != l;
		break;

    default:
		/* bogosity, pretend it didn't match */
		matched = 0;
		php_error(E_WARNING,
					  MODNAME ": mcheck: can't happen: invalid relation %d.",
					  m->reln);
		break;
    }

    return matched;
}

#if HAVE_ZLIB && !defined(COMPILE_DL_ZLIB)
/*
 * compress routines: zmagic() - returns 0 if not recognized, uncompresses
 * and prints information if recognized uncompress(s, method, old, n, newch)
 * - uncompress old into new, using method, return sizeof new
 */

static int zmagic(unsigned char *buf, int nbytes)
{
	if (buf[0] != 0x1f) return 0;

	switch(buf[1]) {
	case 0x9d: /* .Z "x-compress" */
		break; /* not yet supportet */

	case 0x8b: /* .gz "x-gzip" */
#if 0
		if ((newsize = magic_uncompress(i, &newbuf, nbytes)) > 0) {
			tryit(newbuf, newsize, 0);
			
			/* set encoding type in the request record */
			/* TODO r->content_encoding = compr[i].encoding; */
		}
#endif
		break; /* not yet supported */
		
	case 0x1e: /* simply packed ? */
		break; /* not yet supported */
    }

	return 0;
}
#endif 

static void mprint(union VALUETYPE *p, struct magic *m)
{
    char *pp, *rt;
    unsigned long v;

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

    case SHORT:
    case BESHORT:
    case LESHORT:
		v = p->h;
		break;

    case LONG:
    case BELONG:
    case LELONG:
		v = p->l;
		break;

    case STRING:
		if (m->reln == '=') {
			(void) magic_rsl_printf(m->desc, m->value.s);
		}
		else {
			(void) magic_rsl_printf(m->desc, p->s);
		}
		return;

    case DATE:
    case BEDATE:
    case LEDATE:
		/* XXX: not multithread safe */
		pp = ctime((time_t *) & p->l);
		if ((rt = strchr(pp, '\n')) != NULL)
			*rt = '\0';
		(void) magic_rsl_printf(m->desc, pp);
		return;
    default:
		php_error(E_WARNING,
					  MODNAME ": invalid m->type (%d) in mprint().",
					  m->type);
		return;
    }

    v = signextend(m, v) & m->mask;
    (void) magic_rsl_printf(m->desc, (unsigned long) v);
}

/*
 * Convert the byte order of the data we are looking at
 */
static int mconvert(union VALUETYPE *p, struct magic *m)
{
    char *rt;

    switch (m->type) {
    case BYTE:
    case SHORT:
    case LONG:
    case DATE:
		return 1;
    case STRING:
		/* Null terminate and eat the return */
		p->s[sizeof(p->s) - 1] = '\0';
		if ((rt = strchr(p->s, '\n')) != NULL)
			*rt = '\0';
		return 1;
    case BESHORT:
		p->h = (short) ((p->hs[0] << 8) | (p->hs[1]));
		return 1;
    case BELONG:
    case BEDATE:
		p->l = (long)
			((p->hl[0] << 24) | (p->hl[1] << 16) | (p->hl[2] << 8) | (p->hl[3]));
		return 1;
    case LESHORT:
		p->h = (short) ((p->hs[1] << 8) | (p->hs[0]));
		return 1;
    case LELONG:
    case LEDATE:
		p->l = (long)
			((p->hl[3] << 24) | (p->hl[2] << 16) | (p->hl[1] << 8) | (p->hl[0]));
		return 1;
    default:
		php_error(E_WARNING,
					  MODNAME ": invalid type %d in mconvert().", m->type);
		return 0;
    }
}


/* states for the state-machine algorithm in magic_rsl_to_request() */
typedef enum {
    rsl_leading_space, rsl_type, rsl_subtype, rsl_separator, rsl_encoding
} rsl_states;

/* process the RSL and set the MIME info in the request record */
static int magic_rsl_get(char **content_type, char **content_encoding)
{
    int cur_frag,		/* current fragment number/counter */
        cur_pos,		/* current position within fragment */
        type_frag,		/* content type starting point: fragment */
        type_pos,		/* content type starting point: position */
        type_len,		/* content type length */
        encoding_frag,		/* content encoding starting point: fragment */
        encoding_pos,		/* content encoding starting point: position */
        encoding_len;		/* content encoding length */

    magic_rsl *frag;		/* list-traversal pointer */
    rsl_states state;

    magic_req_rec *req_dat;

	TSRMLS_FETCH();

    req_dat = MIME_MAGIC_G(req_dat);

    /* check if we have a result */
    if (!req_dat || !req_dat->head) {
		/* empty - no match, we defer to other Apache modules */
		return MIME_MAGIC_DECLINED;
    }

    /* start searching for the type and encoding */
    state = rsl_leading_space;
    type_frag = type_pos = type_len = 0;
    encoding_frag = encoding_pos = encoding_len = 0;
    for (frag = req_dat->head, cur_frag = 0;
		 frag && frag->next;
		 frag = frag->next, cur_frag++) {
		/* loop through the characters in the fragment */
		for (cur_pos = 0; frag->str[cur_pos]; cur_pos++) {
			if (isspace(frag->str[cur_pos])) {
				/* process whitespace actions for each state */
				if (state == rsl_leading_space) {
					/* eat whitespace in this state */
					continue;
				}
				else if (state == rsl_type) {
					/* whitespace: type has no slash! */
					return MIME_MAGIC_DECLINED;
				}
				else if (state == rsl_subtype) {
					/* whitespace: end of MIME type */
					state++;
					continue;
				}
				else if (state == rsl_separator) {
					/* eat whitespace in this state */
					continue;
				}
				else if (state == rsl_encoding) {
					/* whitespace: end of MIME encoding */
					/* we're done */
					frag = req_dat->tail;
					break;
				}
				else {
					/* should not be possible */
					/* abandon malfunctioning module */
					php_error(E_WARNING,
								  MODNAME ": bad state %d (ws)", state);
					return MIME_MAGIC_DECLINED;
				}
				/* NOTREACHED */
			}
			else if (state == rsl_type &&
					 frag->str[cur_pos] == '/') {
				/* copy the char and go to rsl_subtype state */
				type_len++;
				state++;
			}
			else {
				/* process non-space actions for each state */
				if (state == rsl_leading_space) {
					/* non-space: begin MIME type */
					state++;
					type_frag = cur_frag;
					type_pos = cur_pos;
					type_len = 1;
					continue;
				}
				else if (state == rsl_type ||
						 state == rsl_subtype) {
					/* non-space: adds to type */
					type_len++;
					continue;
				}
				else if (state == rsl_separator) {
					/* non-space: begin MIME encoding */
					state++;
					encoding_frag = cur_frag;
					encoding_pos = cur_pos;
					encoding_len = 1;
					continue;
				}
				else if (state == rsl_encoding) {
					/* non-space: adds to encoding */
					encoding_len++;
					continue;
				}
				else {
					/* should not be possible */
					/* abandon malfunctioning module */
					php_error(E_WARNING,
								  MODNAME ": bad state %d (ns)", state);
					return MIME_MAGIC_DECLINED;
				}
				/* NOTREACHED */
			}
			/* NOTREACHED */
		}
    }

    /* if we ended prior to state rsl_subtype, we had incomplete info */
    if (state != rsl_subtype && state != rsl_separator &&
		state != rsl_encoding) {
		/* defer to other modules */
		return MIME_MAGIC_DECLINED;
    }

    /* save the info in the request record */
    if (state == rsl_subtype || state == rsl_encoding ||
		state == rsl_encoding) {
        char *tmp;
		tmp = rsl_strdup(type_frag, type_pos, type_len);
		/* XXX: this could be done at config time I'm sure... but I'm
		 * confused by all this magic_rsl stuff. -djg */
		/* TODO ap_content_type_tolower(tmp); */
		*content_type = tmp;
    }
    if (state == rsl_encoding) {
        char *tmp;
		tmp = rsl_strdup(encoding_frag,
						 encoding_pos, encoding_len);
		/* XXX: this could be done at config time I'm sure... but I'm
		 * confused by all this magic_rsl stuff. -djg */
		/* TODO ap_str_tolower(tmp); */
		*content_encoding = tmp;
    }

    /* detect memory allocation errors */
    if (!content_type || !(*content_type) || (state == rsl_encoding && !*content_encoding)) {
	return MIME_MAGIC_ERROR;
    }

    /* success! */
    return MIME_MAGIC_OK;
}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */