uri.c

SIP 1.5.0源代码

        return(0);

    /*
     * failed, fallback to reg_name
     */
    if (!IS_REG_NAME(cur)) {
	return(5);
    }
    NEXT(cur);
    while (IS_REG_NAME(cur)) NEXT(cur);
    if (uri != NULL) {
	if (uri->server != NULL) xmlFree(uri->server);
	uri->server = NULL;
	if (uri->user != NULL) xmlFree(uri->user);
	uri->user = NULL;
	if (uri->authority != NULL) xmlFree(uri->authority);
	uri->authority = xmlURIUnescapeString(*str, cur - *str, NULL);
    }
    *str = cur;
    return(0);
}

/**
 * xmlParseURIHierPart:
 * @uri:  pointer to an URI structure
 * @str:  pointer to the string to analyze
 *
 * Parse an URI hirarchical part
 * 
 * hier_part = ( net_path | abs_path ) [ "?" query ]
 * abs_path = "/"  path_segments
 * net_path = "//" authority [ abs_path ]
 *
 * Returns 0 or the error code
 */
int
xmlParseURIHierPart(xmlURIPtr uri, const char **str) {
    int ret;
    const char *cur;

    if (str == NULL)
	return(-1);
    
    cur = *str;

    if ((cur[0] == '/') && (cur[1] == '/')) {
	cur += 2;
	ret = xmlParseURIAuthority(uri, &cur);
	if (ret != 0)
	    return(ret);
	if (cur[0] == '/') {
	    cur++;
	    ret = xmlParseURIPathSegments(uri, &cur, 1);
	}
    } else if (cur[0] == '/') {
	cur++;
	ret = xmlParseURIPathSegments(uri, &cur, 1);
    } else {
	return(4);
    }
    if (ret != 0)
	return(ret);
    if (*cur == '?') {
	cur++;
	ret = xmlParseURIQuery(uri, &cur);
	if (ret != 0)
	    return(ret);
    }
    *str = cur;
    return(0);
}

/**
 * xmlParseAbsoluteURI:
 * @uri:  pointer to an URI structure
 * @str:  pointer to the string to analyze
 *
 * Parse an URI reference string and fills in the appropriate fields
 * of the @uri structure
 * 
 * absoluteURI   = scheme ":" ( hier_part | opaque_part )
 *
 * Returns 0 or the error code
 */
int
xmlParseAbsoluteURI(xmlURIPtr uri, const char **str) {
    int ret;

    if (str == NULL)
	return(-1);
    
    ret = xmlParseURIScheme(uri, str);
    if (ret != 0) return(ret);
    if (**str != ':')
	return(1);
    (*str)++;
    if (**str == '/')
	return(xmlParseURIHierPart(uri, str));
    return(xmlParseURIOpaquePart(uri, str));
}

/**
 * xmlParseRelativeURI:
 * @uri:  pointer to an URI structure
 * @str:  pointer to the string to analyze
 *
 * Parse an relative URI string and fills in the appropriate fields
 * of the @uri structure
 * 
 * relativeURI = ( net_path | abs_path | rel_path ) [ "?" query ]
 * abs_path = "/"  path_segments
 * net_path = "//" authority [ abs_path ]
 * rel_path = rel_segment [ abs_path ]
 *
 * Returns 0 or the error code
 */
int
xmlParseRelativeURI(xmlURIPtr uri, const char **str) {
    int ret = 0;
    const char *cur;

    if (str == NULL)
	return(-1);
    
    cur = *str;
    if ((cur[0] == '/') && (cur[1] == '/')) {
	cur += 2;
	ret = xmlParseURIAuthority(uri, &cur);
	if (ret != 0)
	    return(ret);
	if (cur[0] == '/') {
	    cur++;
	    ret = xmlParseURIPathSegments(uri, &cur, 1);
	}
    } else if (cur[0] == '/') {
	cur++;
	ret = xmlParseURIPathSegments(uri, &cur, 1);
    } else {
	ret = xmlParseURIRelSegment(uri, &cur);
	if (ret != 0)
	    return(ret);
	if (cur[0] == '/') {
	    cur++;
	    ret = xmlParseURIPathSegments(uri, &cur, 1);
	}
    }
    if (ret != 0)
	return(ret);
    if (*cur == '?') {
	cur++;
	ret = xmlParseURIQuery(uri, &cur);
	if (ret != 0)
	    return(ret);
    }
    *str = cur;
    return(ret);
}

/**
 * xmlParseURIReference:
 * @uri:  pointer to an URI structure
 * @str:  the string to analyze
 *
 * Parse an URI reference string and fills in the appropriate fields
 * of the @uri structure
 * 
 * URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
 *
 * Returns 0 or the error code
 */
int
xmlParseURIReference(xmlURIPtr uri, const char *str) {
    int ret;
    const char *tmp = str;

    if (str == NULL)
	return(-1);
    xmlCleanURI(uri);

    /*
     * Try first to parse aboslute refs, then fallback to relative if
     * it fails.
     */
    ret = xmlParseAbsoluteURI(uri, &str);
    if (ret != 0) {
	xmlCleanURI(uri);
	str = tmp;
        ret = xmlParseRelativeURI(uri, &str);
    }
    if (ret != 0) {
	xmlCleanURI(uri);
	return(ret);
    }

    if (*str == '#') {
	str++;
	ret = xmlParseURIFragment(uri, &str);
	if (ret != 0) return(ret);
    }
    if (*str != 0) {
	xmlCleanURI(uri);
	return(1);
    }
    return(0);
}

/**
 * xmlNormalizeURIPath:
 * @path:  pointer to the path string
 *
 * applies the 5 normalization steps to a path string
 * Normalization occurs directly on the string, no new allocation is done
 *
 * Returns 0 or an error code
 */
int
xmlNormalizeURIPath(char *path) {
    int cur, out;

    if (path == NULL)
	return(-1);
    cur = 0;
    out = 0;
    while ((path[cur] != 0) && (path[cur] != '/')) cur++;
    if (path[cur] == 0)
	return(0);

    /* we are positionned at the beginning of the first segment */
    cur++;
    out = cur;

    /*
     * Analyze each segment in sequence.
     */
    while (path[cur] != 0) {
	/*
	 * c) All occurrences of "./", where "." is a complete path segment,
	 *    are removed from the buffer string.
	 */
	if ((path[cur] == '.') && (path[cur + 1] == '/')) {
	    cur += 2;
	    continue;
	}

	/*
	 * d) If the buffer string ends with "." as a complete path segment,
	 *    that "." is removed.
	 */
	if ((path[cur] == '.') && (path[cur + 1] == 0)) {
	    path[out] = 0;
	    break;
	}

	/* read the segment */
	while ((path[cur] != 0) && (path[cur] != '/')) {
	    path[out++] = path[cur++];
	}
	path[out++] = path[cur];
	if (path[cur] != 0) {
	    cur++;
	}
    }

    cur = 0;
    out = 0;
    while ((path[cur] != 0) && (path[cur] != '/')) cur++;
    if (path[cur] == 0)
	return(0);
    /* we are positionned at the beginning of the first segment */
    cur++;
    out = cur;
    /*
     * Analyze each segment in sequence.
     */
    while (path[cur] != 0) {
	/*
	 * e) All occurrences of "<segment>/../", where <segment> is a
	 *    complete path segment not equal to "..", are removed from the
	 *    buffer string.  Removal of these path segments is performed
	 *    iteratively, removing the leftmost matching pattern on each
	 *    iteration, until no matching pattern remains.
	 */
	if ((cur > 1) && (out > 1) &&
	    (path[cur] == '/') && (path[cur + 1] == '.') &&
	    (path[cur + 2] == '.') && (path[cur + 3] == '/') &&
	    ((path[out] != '.') || (path[out - 1] != '.') ||
	     (path[out - 2] != '/'))) {
	    cur += 3;
	    out --;
	    while ((out > 0) && (path[out] != '/')) { out --; }
	    path[out] = 0;
            continue;
	}

	/*
	 * f) If the buffer string ends with "<segment>/..", where <segment>
	 *    is a complete path segment not equal to "..", that
	 *    "<segment>/.." is removed.
	 */
	if ((path[cur] == '/') && (path[cur + 1] == '.') &&
	    (path[cur + 2] == '.') && (path[cur + 3] == 0) &&
	    ((path[out] != '.') || (path[out - 1] != '.') ||
	     (path[out - 2] != '/'))) {
	    cur += 4;
	    out --;
	    while ((out > 0) && (path[out - 1] != '/')) { out --; }
	    path[out] = 0;
            continue;
	}
        
	path[out++] = path[cur++]; /* / or 0 */
    }
    path[out] = 0;

    /*
     * g) If the resulting buffer string still begins with one or more
     *    complete path segments of "..", then the reference is 
     *    considered to be in error. Implementations may handle this
     *    error by retaining these components in the resolved path (i.e.,
     *    treating them as part of the final URI), by removing them from
     *    the resolved path (i.e., discarding relative levels above the
     *    root), or by avoiding traversal of the reference.
     *
     * We discard them from the final path.
     */
    cur = 0;
    while ((path[cur] == '/') && (path[cur + 1] == '.') &&
	   (path[cur + 2] == '.'))
	cur += 3;
    if (cur != 0) {
	out = 0;
	while (path[cur] != 0) path[out++] = path[cur++];
	path[out] = 0;
    }
    return(0);
}

/**
 * xmlBuildURI:
 * @URI:  the URI instance found in the document
 * @base:  the base value
 *
 * Computes he final URI of the reference done by checking that
 * the given URI is valid, and building the final URI using the
 * base URI. This is processed according to section 5.2 of the 
 * RFC 2396
 *
 * 5.2. Resolving Relative References to Absolute Form
 *
 * Returns a new URI string (to be freed by the caller) or NULL in case
 *         of error.
 */
xmlChar *
xmlBuildURI(const xmlChar *URI, const xmlChar *base) {
    xmlChar *val = NULL;
    int ret, len, index, cur, out;
    xmlURIPtr ref = NULL;
    xmlURIPtr bas = NULL;
    xmlURIPtr res = NULL;


    /*
     * 1) The URI reference is parsed into the potential four components and
     *    fragment identifier, as described in Section 4.3.
     */
    ref = xmlCreateURI();
    if (ref == NULL)
	goto done;
    ret = xmlParseURIReference(ref, (const char *) URI);
    if (ret != 0)
	goto done;
    bas = xmlCreateURI();
    if (bas == NULL)
	goto done;
    ret = xmlParseURIReference(bas, (const char *) base);
    if (ret != 0)
	goto done;

    /*
     * 2) If the path component is empty and the scheme, authority, and
     *    query components are undefined, then it is a reference to the
     *    current document and we are done.  Otherwise, the reference URI's
     *    query and fragment components are defined as found (or not found)
     *    within the URI reference and not inherited from the base URI.
     */
    res = xmlCreateURI();
    if (res == NULL)
	goto done;
    if ((ref->scheme == NULL) && (ref->path == NULL) &&
	((ref->authority == NULL) && (ref->server == NULL)) &&
	(ref->query == NULL)) {
	if (ref->fragment == NULL)
	    goto done;
        res->fragment = xmlMemStrdup(ref->fragment);
	val = xmlSaveUri(res);
	goto done;
    }

    /*
     * 3) If the scheme component is defined, indicating that the reference
     *    starts with a scheme name, then the reference is interpreted as an
     *    absolute URI and we are done.  Otherwise, the reference URI's
     *    scheme is inherited from the base URI's scheme component.
     */
    if (ref->scheme != NULL) {
	val = xmlSaveUri(ref);
	goto done;
    }
    res->scheme = xmlMemStrdup(bas->scheme);

    /*
     * 4) If the authority component is defined, then the reference is a
     *    network-path and we skip to step 7.  Otherwise, the reference
     *    URI's authority is inherited from the base URI's authority
     *    component, which will also be undefined if the URI scheme does not
     *    use an authority component.
     */
    if ((ref->authority != NULL) || (ref->server != NULL)) {
	if (ref->authority != NULL)
	    res->authority = xmlMemStrdup(ref->authority);
	else {
	    res->server = xmlMemStrdup(ref->server);
	    if (ref->user != NULL)
		res->user = xmlMemStrdup(ref->user);
            res->port = ref->port;		
	}
	if (ref->path != NULL)
	    res->path = xmlMemStrdup(ref->path);
	if (ref->query != NULL)
	    res->query = xmlMemStrdup(ref->query);
	if (ref->fragment != NULL)
	    res->fragment = xmlMemStrdup(ref->fragment);
	goto step_7;
    }
    if (bas->authority != NULL)
	res->authority = xmlMemStrdup(bas->authority);
    else if (bas->server != NULL) {
	res->server = xmlMemStrdup(bas->server);
	if (bas->user != NULL)
	    res->user = xmlMemStrdup(bas->user);
	res->port = bas->port;		
    }

    /*
     * 5) If the path component begins with a slash character ("/"), then
     *    the reference is an absolute-path and we skip to step 7.
     */
    if ((ref->path != NULL) && (ref->path[0] == '/')) {
	res->path = xmlMemStrdup(ref->path);
	if (ref->query != NULL)
	    res->query = xmlMemStrdup(ref->query);
	if (ref->fragment != NULL)
	    res->fragment = xmlMemStrdup(ref->fragment);
	goto step_7;
    }


    /*
     * 6) If this step is reached, then we are resolving a relative-path
     *    reference.  The relative path needs to be merged with the base
     *    URI's path.  Although there are many ways to do this, we will
     *    describe a simple method using a separate string buffer.
     *
     * Allocate a buffer large enough for the result string.
     */
    len = 2; /* extra / and 0 */
    if (ref->path != NULL)
	len += strlen(ref->path);
    if (bas->path != NULL)
	len += strlen(bas->path);
    res->path = (char *) xmlMalloc(len);
    if (res->path == NULL) {
	fprintf(stderr, "xmlBuildURI: out of memory\n");
	goto done;
    }
    res->path[0] = 0;

    /*
     * a) All but the last segment of the base URI's path component is
     *    copied to the buffer.  In other words, any characters after the
     *    last (right-most) slash character, if any, are excluded.
     */
    cur = 0;
    out = 0;
    if (bas->path != NULL) {
	while (bas->path[cur] != 0) {
	    while ((bas->path[cur] != 0) && (bas->path[cur] != '/'))
		cur++;
	    if (bas->path[cur] == 0)
		break;

	    cur++;
	    while (out < cur) {
		res->path[out] = bas->path[out];
		out++;
	    }
	}
    }
    res->path[out] = 0;

    /*
     * b) The reference's path component is appended to the buffer
     *    string.
     */
    if (ref->path != NULL) {
	index = 0;
	while (ref->path[index] != 0) {
	    res->path[out++] = ref->path[index++];
	}
    }
    res->path[out] = 0;

    /*
     * Steps c) to h) are really path normalization steps
     */
    xmlNormalizeURIPath(res->path);

step_7:

    /*
     * 7) The resulting URI components, including any inherited from the
     *    base URI, are recombined to give the absolute form of the URI
     *    reference.
     */
    val = xmlSaveUri(res);

done:
    if (ref != NULL)
	xmlFreeURI(ref);
    if (base != NULL)
	xmlFreeURI(bas);
    if (res != NULL)
	xmlFreeURI(res);
    return(val);
}