request.c

来自「Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相」· C语言 代码 · 共 1,783 行 · 第 1/5 页

    /* Merge our cache->dir_conf_merged construct with the r->per_dir_configs,
     * and note the end result to (potentially) skip this step next time.
     */
    if (now_merged) {
        r->per_dir_config = ap_merge_per_dir_configs(r->pool,
                                                     r->per_dir_config,
                                                     now_merged);
    }
    cache->per_dir_result = r->per_dir_config;

    return OK;
}

/*****************************************************************
 *
 * The sub_request mechanism.
 *
 * Fns to look up a relative URI from, e.g., a map file or SSI document.
 * These do all access checks, etc., but don't actually run the transaction
 * ... use run_sub_req below for that.  Also, be sure to use destroy_sub_req
 * as appropriate if you're likely to be creating more than a few of these.
 * (An early Apache version didn't destroy the sub_reqs used in directory
 * indexing.  The result, when indexing a directory with 800-odd files in
 * it, was massively excessive storage allocation).
 *
 * Note more manipulation of protocol-specific vars in the request
 * structure...
 */

static request_rec *make_sub_request(const request_rec *r,
                                     ap_filter_t *next_filter)
{
    apr_pool_t *rrp;
    request_rec *rnew;

    apr_pool_create(&rrp, r->pool);
    apr_pool_tag(rrp, "subrequest");
    rnew = apr_pcalloc(rrp, sizeof(request_rec));
    rnew->pool = rrp;

    rnew->hostname       = r->hostname;
    rnew->request_time   = r->request_time;
    rnew->connection     = r->connection;
    rnew->server         = r->server;

    rnew->request_config = ap_create_request_config(rnew->pool);

    /* Start a clean config from this subrequest's vhost.  Optimization in
     * Location/File/Dir walks from the parent request assure that if the
     * config blocks of the subrequest match the parent request, no merges
     * will actually occur (and generally a minimal number of merges are
     * required, even if the parent and subrequest aren't quite identical.)
     */
    rnew->per_dir_config = r->server->lookup_defaults;

    rnew->htaccess = r->htaccess;
    rnew->allowed_methods = ap_make_method_list(rnew->pool, 2);

    /* make a copy of the allowed-methods list */
    ap_copy_method_list(rnew->allowed_methods, r->allowed_methods);

    /* start with the same set of output filters */
    if (next_filter) {
        /* while there are no input filters for a subrequest, we will
         * try to insert some, so if we don't have valid data, the code
         * will seg fault.
         */
        rnew->input_filters = r->input_filters;
        rnew->proto_input_filters = r->proto_input_filters;
        rnew->output_filters = next_filter;
        rnew->proto_output_filters = r->proto_output_filters;
        ap_add_output_filter_handle(ap_subreq_core_filter_handle,
                                    NULL, rnew, rnew->connection);
    }
    else {
        /* If NULL - we are expecting to be internal_fast_redirect'ed
         * to this subrequest - or this request will never be invoked.
         * Ignore the original request filter stack entirely, and
         * drill the input and output stacks back to the connection.
         */
        rnew->proto_input_filters = r->proto_input_filters;
        rnew->proto_output_filters = r->proto_output_filters;

        rnew->input_filters = r->proto_input_filters;
        rnew->output_filters = r->proto_output_filters;
    }

    /* no input filters for a subrequest */

    ap_set_sub_req_protocol(rnew, r);

    /* We have to run this after we fill in sub req vars,
     * or the r->main pointer won't be setup
     */
    ap_run_create_request(rnew);

    return rnew;
}

AP_CORE_DECLARE_NONSTD(apr_status_t) ap_sub_req_output_filter(ap_filter_t *f,
                                                              apr_bucket_brigade *bb)
{
    apr_bucket *e = APR_BRIGADE_LAST(bb);

    if (APR_BUCKET_IS_EOS(e)) {
        apr_bucket_delete(e);
    }

    if (!APR_BRIGADE_EMPTY(bb)) {
        return ap_pass_brigade(f->next, bb);
    }

    return APR_SUCCESS;
}


AP_DECLARE(int) ap_some_auth_required(request_rec *r)
{
    /* Is there a require line configured for the type of *this* req? */

    const apr_array_header_t *reqs_arr = ap_requires(r);
    require_line *reqs;
    int i;

    if (!reqs_arr) {
        return 0;
    }

    reqs = (require_line *) reqs_arr->elts;

    for (i = 0; i < reqs_arr->nelts; ++i) {
        if (reqs[i].method_mask & (AP_METHOD_BIT << r->method_number)) {
            return 1;
        }
    }

    return 0;
}


AP_DECLARE(request_rec *) ap_sub_req_method_uri(const char *method,
                                                const char *new_uri,
                                                const request_rec *r,
                                                ap_filter_t *next_filter)
{
    request_rec *rnew;
    int res;
    char *udir;

    rnew = make_sub_request(r, next_filter);

    /* would be nicer to pass "method" to ap_set_sub_req_protocol */
    rnew->method = method;
    rnew->method_number = ap_method_number_of(method);

    if (new_uri[0] == '/') {
        ap_parse_uri(rnew, new_uri);
    }
    else {
        udir = ap_make_dirstr_parent(rnew->pool, r->uri);
        udir = ap_escape_uri(rnew->pool, udir);    /* re-escape it */
        ap_parse_uri(rnew, ap_make_full_path(rnew->pool, udir, new_uri));
    }

    /* We cannot return NULL without violating the API. So just turn this
     * subrequest into a 500 to indicate the failure. */
    if (ap_is_recursion_limit_exceeded(r)) {
        rnew->status = HTTP_INTERNAL_SERVER_ERROR;
        return rnew;
    }

    /* lookup_uri 
     * If the content can be served by the quick_handler, we can
     * safely bypass request_internal processing.
     */
    res = ap_run_quick_handler(rnew, 1);

    if (res != OK) {
        if ((res = ap_process_request_internal(rnew))) {
            rnew->status = res;
        }
    } 

    return rnew;
}

AP_DECLARE(request_rec *) ap_sub_req_lookup_uri(const char *new_uri,
                                                const request_rec *r,
                                                ap_filter_t *next_filter)
{
    return ap_sub_req_method_uri("GET", new_uri, r, next_filter);
}

AP_DECLARE(request_rec *) ap_sub_req_lookup_dirent(const apr_finfo_t *dirent,
                                                   const request_rec *r,
                                                   int subtype,
                                                   ap_filter_t *next_filter)
{
    request_rec *rnew;
    int res;
    char *fdir;
    char *udir;

    rnew = make_sub_request(r, next_filter);

    /* Special case: we are looking at a relative lookup in the same directory.
     * This is 100% safe, since dirent->name just came from the filesystem.
     */
    if (r->path_info && *r->path_info) {
        /* strip path_info off the end of the uri to keep it in sync
         * with r->filename, which has already been stripped by directory_walk,
         * merge the dirent->name, and then, if the caller wants us to remerge
         * the original path info, do so.  Note we never fix the path_info back
         * to r->filename, since dir_walk would do so (but we don't expect it
         * to happen in the usual cases)
         */
        udir = apr_pstrdup(rnew->pool, r->uri);
        udir[ap_find_path_info(udir, r->path_info)] = '\0';
        udir = ap_make_dirstr_parent(rnew->pool, udir);

        rnew->uri = ap_make_full_path(rnew->pool, udir, dirent->name);
        if (subtype == AP_SUBREQ_MERGE_ARGS) {
            rnew->uri = ap_make_full_path(rnew->pool, rnew->uri, r->path_info + 1);
            rnew->path_info = apr_pstrdup(rnew->pool, r->path_info);
        }
        rnew->uri = ap_escape_uri(rnew->pool, rnew->uri);
    }
    else {
        udir = ap_make_dirstr_parent(rnew->pool, r->uri);
        rnew->uri = ap_escape_uri(rnew->pool, ap_make_full_path(rnew->pool,
                                                                udir,
                                                                dirent->name));
    }

    fdir = ap_make_dirstr_parent(rnew->pool, r->filename);
    rnew->filename = ap_make_full_path(rnew->pool, fdir, dirent->name);
    if (r->canonical_filename == r->filename) {
        rnew->canonical_filename = rnew->filename;
    }

    /* XXX This is now less relevant; we will do a full location walk
     * these days for this case.  Preserve the apr_stat results, and
     * perhaps we also tag that symlinks were tested and/or found for
     * r->filename.
     */
    rnew->per_dir_config = r->server->lookup_defaults;

    if ((dirent->valid & APR_FINFO_MIN) != APR_FINFO_MIN) {
        /*
         * apr_dir_read isn't very complete on this platform, so
         * we need another apr_lstat (or simply apr_stat if we allow
         * all symlinks here.)  If this is an APR_LNK that resolves
         * to an APR_DIR, then we will rerun everything anyways...
         * this should be safe.
         */
        apr_status_t rv;
        if (ap_allow_options(rnew) & OPT_SYM_LINKS) {
            if (((rv = apr_stat(&rnew->finfo, rnew->filename,
                                APR_FINFO_MIN, rnew->pool)) != APR_SUCCESS)
                && (rv != APR_INCOMPLETE)) {
                rnew->finfo.filetype = 0;
            }
        }
        else {
            if (((rv = apr_lstat(&rnew->finfo, rnew->filename,
                                 APR_FINFO_MIN, rnew->pool)) != APR_SUCCESS)
                && (rv != APR_INCOMPLETE)) {
                rnew->finfo.filetype = 0;
            }
        }
    }
    else {
        memcpy(&rnew->finfo, dirent, sizeof(apr_finfo_t));
    }

    if (rnew->finfo.filetype == APR_LNK) {
        /*
         * Resolve this symlink.  We should tie this back to dir_walk's cache
         */
        if ((res = resolve_symlink(rnew->filename, &rnew->finfo,
                                   ap_allow_options(rnew), rnew->pool))
            != OK) {
            rnew->status = res;
            return rnew;
        }
    }

    if (rnew->finfo.filetype == APR_DIR) {
        /* ap_make_full_path overallocated the buffers
         * by one character to help us out here.
         */
        strcpy(rnew->filename + strlen(rnew->filename), "/");
        if (!rnew->path_info || !*rnew->path_info) {
            strcpy(rnew->uri  + strlen(rnew->uri ), "/");
        }
    }

    /* fill in parsed_uri values
     */
    if (r->args && *r->args && (subtype == AP_SUBREQ_MERGE_ARGS)) {
        ap_parse_uri(rnew, apr_pstrcat(r->pool, rnew->uri, "?",
                                       r->args, NULL));
    }
    else {
        ap_parse_uri(rnew, rnew->uri);
    }

    /* We cannot return NULL without violating the API. So just turn this
     * subrequest into a 500. */
    if (ap_is_recursion_limit_exceeded(r)) {
        rnew->status = HTTP_INTERNAL_SERVER_ERROR;
        return rnew;
    }

    if ((res = ap_process_request_internal(rnew))) {
        rnew->status = res;
    }

    return rnew;
}

AP_DECLARE(request_rec *) ap_sub_req_lookup_file(const char *new_file,
                                                 const request_rec *r,
                                                 ap_filter_t *next_filter)
{
    request_rec *rnew;
    int res;
    char *fdir;
    apr_size_t fdirlen;

    rnew = make_sub_request(r, next_filter);

    fdir = ap_make_dirstr_parent(rnew->pool, r->filename);
    fdirlen = strlen(fdir);

    /* Translate r->filename, if it was canonical, it stays canonical
     */
    if (r->canonical_filename == r->filename) {
        rnew->canonical_filename = (char*)(1);
    }

    if (apr_filepath_merge(&rnew->filename, fdir, new_file,
                           APR_FILEPATH_TRUENAME, rnew->pool) != APR_SUCCESS) {
        rnew->status = HTTP_FORBIDDEN;
        return rnew;
    }

    if (rnew->canonical_filename) {
        rnew->canonical_filename = rnew->filename;
    }

    /*
     * Check for a special case... if there are no '/' characters in new_file
     * at all, and the path was the same, then we