diff options
Diffstat (limited to 'modules/proxy/mod_proxy_scgi.c')
| -rw-r--r-- | modules/proxy/mod_proxy_scgi.c | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/modules/proxy/mod_proxy_scgi.c b/modules/proxy/mod_proxy_scgi.c new file mode 100644 index 0000000..11f75de --- /dev/null +++ b/modules/proxy/mod_proxy_scgi.c @@ -0,0 +1,674 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * mod_proxy_scgi.c + * Proxy backend module for the SCGI protocol + * (http://python.ca/scgi/protocol.txt) + * + * Andr� Malo (nd/perlig.de), August 2007 + */ + +#define APR_WANT_MEMFUNC +#define APR_WANT_STRFUNC +#include "apr_strings.h" +#include "ap_hooks.h" +#include "apr_optional_hooks.h" +#include "apr_buckets.h" + +#include "httpd.h" +#include "http_config.h" +#include "http_log.h" +#include "http_protocol.h" +#include "http_request.h" +#include "util_script.h" + +#include "mod_proxy.h" +#include "scgi.h" + + +#define SCHEME "scgi" +#define PROXY_FUNCTION "SCGI" +#define SCGI_MAGIC "SCGI" +#define SCGI_PROTOCOL_VERSION "1" + +/* just protect from typos */ +#define CONTENT_LENGTH "CONTENT_LENGTH" +#define GATEWAY_INTERFACE "GATEWAY_INTERFACE" + +module AP_MODULE_DECLARE_DATA proxy_scgi_module; + + +typedef enum { + scgi_internal_redirect, + scgi_sendfile +} scgi_request_type; + +typedef struct { + const char *location; /* target URL */ + scgi_request_type type; /* type of request */ +} scgi_request_config; + +const char *scgi_sendfile_off = "off"; +const char *scgi_sendfile_on = "X-Sendfile"; +const char *scgi_internal_redirect_off = "off"; +const char *scgi_internal_redirect_on = "Location"; + +typedef struct { + const char *sendfile; + const char *internal_redirect; +} scgi_config; + + +/* + * We create our own bucket type, which is actually derived (c&p) from the + * socket bucket. + * Maybe some time this should be made more abstract (like passing an + * interception function to read or something) and go into the ap_ or + * even apr_ namespace. + */ + +typedef struct { + apr_socket_t *sock; + apr_off_t *counter; +} socket_ex_data; + +static apr_bucket *bucket_socket_ex_create(socket_ex_data *data, + apr_bucket_alloc_t *list); + + +static apr_status_t bucket_socket_ex_read(apr_bucket *a, const char **str, + apr_size_t *len, + apr_read_type_e block) +{ + socket_ex_data *data = a->data; + apr_socket_t *p = data->sock; + char *buf; + apr_status_t rv; + apr_interval_time_t timeout; + + if (block == APR_NONBLOCK_READ) { + apr_socket_timeout_get(p, &timeout); + apr_socket_timeout_set(p, 0); + } + + *str = NULL; + *len = APR_BUCKET_BUFF_SIZE; + buf = apr_bucket_alloc(*len, a->list); + + rv = apr_socket_recv(p, buf, len); + + if (block == APR_NONBLOCK_READ) { + apr_socket_timeout_set(p, timeout); + } + + if (rv != APR_SUCCESS && rv != APR_EOF) { + apr_bucket_free(buf); + return rv; + } + + if (*len > 0) { + apr_bucket_heap *h; + + /* count for stats */ + *data->counter += *len; + + /* Change the current bucket to refer to what we read */ + a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free); + h = a->data; + h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */ + *str = buf; + APR_BUCKET_INSERT_AFTER(a, bucket_socket_ex_create(data, a->list)); + } + else { + apr_bucket_free(buf); + a = apr_bucket_immortal_make(a, "", 0); + *str = a->data; + } + return APR_SUCCESS; +} + +static const apr_bucket_type_t bucket_type_socket_ex = { + "SOCKET_EX", 5, APR_BUCKET_DATA, + apr_bucket_destroy_noop, + bucket_socket_ex_read, + apr_bucket_setaside_notimpl, + apr_bucket_split_notimpl, + apr_bucket_copy_notimpl +}; + +static apr_bucket *bucket_socket_ex_make(apr_bucket *b, socket_ex_data *data) +{ + b->type = &bucket_type_socket_ex; + b->length = (apr_size_t)(-1); + b->start = -1; + b->data = data; + return b; +} + +static apr_bucket *bucket_socket_ex_create(socket_ex_data *data, + apr_bucket_alloc_t *list) +{ + apr_bucket *b = apr_bucket_alloc(sizeof(*b), list); + + APR_BUCKET_INIT(b); + b->free = apr_bucket_free; + b->list = list; + return bucket_socket_ex_make(b, data); +} + + +/* + * Canonicalize scgi-like URLs. + */ +static int scgi_canon(request_rec *r, char *url) +{ + char *host, sport[sizeof(":65535")]; + const char *err, *path; + apr_port_t port, def_port; + + if (strncasecmp(url, SCHEME "://", sizeof(SCHEME) + 2)) { + return DECLINED; + } + url += sizeof(SCHEME); /* Keep slashes */ + + port = def_port = SCGI_DEF_PORT; + + err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port); + if (err) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00857) + "error parsing URL %s: %s", url, err); + return HTTP_BAD_REQUEST; + } + + if (port != def_port) { + apr_snprintf(sport, sizeof(sport), ":%u", port); + } + else { + sport[0] = '\0'; + } + + if (ap_strchr(host, ':')) { /* if literal IPv6 address */ + host = apr_pstrcat(r->pool, "[", host, "]", NULL); + } + + path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, 0, + r->proxyreq); + if (!path) { + return HTTP_BAD_REQUEST; + } + + r->filename = apr_pstrcat(r->pool, "proxy:" SCHEME "://", host, sport, "/", + path, NULL); + + if (apr_table_get(r->subprocess_env, "proxy-scgi-pathinfo")) { + r->path_info = apr_pstrcat(r->pool, "/", path, NULL); + } + + return OK; +} + + +/* + * Send a block of data, ensure, everything is sent + */ +static int sendall(proxy_conn_rec *conn, const char *buf, apr_size_t length, + request_rec *r) +{ + apr_status_t rv; + apr_size_t written; + + while (length > 0) { + written = length; + if ((rv = apr_socket_send(conn->sock, buf, &written)) != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00858) + "sending data to %s:%u failed", + conn->hostname, conn->port); + return HTTP_SERVICE_UNAVAILABLE; + } + + /* count for stats */ + conn->worker->s->transferred += written; + buf += written; + length -= written; + } + + return OK; +} + + +/* + * Send SCGI header block + */ +static int send_headers(request_rec *r, proxy_conn_rec *conn) +{ + char *buf, *cp, *bodylen; + const char *ns_len; + const apr_array_header_t *env_table; + const apr_table_entry_t *env; + int j; + apr_size_t len, bodylen_size; + apr_size_t headerlen = sizeof(CONTENT_LENGTH) + + sizeof(SCGI_MAGIC) + + sizeof(SCGI_PROTOCOL_VERSION); + + ap_add_common_vars(r); + ap_add_cgi_vars(r); + + /* + * The header blob basically takes the environment and concatenates + * keys and values using 0 bytes. There are special treatments here: + * - GATEWAY_INTERFACE and SCGI_MAGIC are dropped + * - CONTENT_LENGTH is always set and must be sent as the very first + * variable + * + * Additionally it's wrapped into a so-called netstring (see SCGI spec) + */ + env_table = apr_table_elts(r->subprocess_env); + env = (apr_table_entry_t *)env_table->elts; + for (j = 0; j < env_table->nelts; ++j) { + if ( (!strcmp(env[j].key, GATEWAY_INTERFACE)) + || (!strcmp(env[j].key, CONTENT_LENGTH)) + || (!strcmp(env[j].key, SCGI_MAGIC))) { + continue; + } + headerlen += strlen(env[j].key) + strlen(env[j].val) + 2; + } + bodylen = apr_psprintf(r->pool, "%" APR_OFF_T_FMT, r->remaining); + bodylen_size = strlen(bodylen) + 1; + headerlen += bodylen_size; + + ns_len = apr_psprintf(r->pool, "%" APR_SIZE_T_FMT ":", headerlen); + len = strlen(ns_len); + headerlen += len + 1; /* 1 == , */ + cp = buf = apr_palloc(r->pool, headerlen); + memcpy(cp, ns_len, len); + cp += len; + + memcpy(cp, CONTENT_LENGTH, sizeof(CONTENT_LENGTH)); + cp += sizeof(CONTENT_LENGTH); + memcpy(cp, bodylen, bodylen_size); + cp += bodylen_size; + memcpy(cp, SCGI_MAGIC, sizeof(SCGI_MAGIC)); + cp += sizeof(SCGI_MAGIC); + memcpy(cp, SCGI_PROTOCOL_VERSION, sizeof(SCGI_PROTOCOL_VERSION)); + cp += sizeof(SCGI_PROTOCOL_VERSION); + + for (j = 0; j < env_table->nelts; ++j) { + if ( (!strcmp(env[j].key, GATEWAY_INTERFACE)) + || (!strcmp(env[j].key, CONTENT_LENGTH)) + || (!strcmp(env[j].key, SCGI_MAGIC))) { + continue; + } + len = strlen(env[j].key) + 1; + memcpy(cp, env[j].key, len); + cp += len; + len = strlen(env[j].val) + 1; + memcpy(cp, env[j].val, len); + cp += len; + } + *cp++ = ','; + + return sendall(conn, buf, headerlen, r); +} + + +/* + * Send request body (if any) + */ +static int send_request_body(request_rec *r, proxy_conn_rec *conn) +{ + if (ap_should_client_block(r)) { + char *buf = apr_palloc(r->pool, AP_IOBUFSIZE); + int status; + long readlen; + + readlen = ap_get_client_block(r, buf, AP_IOBUFSIZE); + while (readlen > 0) { + status = sendall(conn, buf, (apr_size_t)readlen, r); + if (status != OK) { + return HTTP_SERVICE_UNAVAILABLE; + } + readlen = ap_get_client_block(r, buf, AP_IOBUFSIZE); + } + if (readlen == -1) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00859) + "receiving request body failed"); + return HTTP_INTERNAL_SERVER_ERROR; + } + } + + return OK; +} + + +/* + * Fetch response from backend and pass back to the front + */ +static int pass_response(request_rec *r, proxy_conn_rec *conn) +{ + apr_bucket_brigade *bb; + apr_bucket *b; + const char *location; + scgi_config *conf; + socket_ex_data *sock_data; + int status; + + sock_data = apr_palloc(r->pool, sizeof(*sock_data)); + sock_data->sock = conn->sock; + sock_data->counter = &conn->worker->s->read; + + bb = apr_brigade_create(r->pool, r->connection->bucket_alloc); + b = bucket_socket_ex_create(sock_data, r->connection->bucket_alloc); + APR_BRIGADE_INSERT_TAIL(bb, b); + b = apr_bucket_eos_create(r->connection->bucket_alloc); + APR_BRIGADE_INSERT_TAIL(bb, b); + + status = ap_scan_script_header_err_brigade_ex(r, bb, NULL, + APLOG_MODULE_INDEX); + if (status != OK) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00860) + "error reading response headers from %s:%u", + conn->hostname, conn->port); + r->status_line = NULL; + apr_brigade_destroy(bb); + return status; + } + + conf = ap_get_module_config(r->per_dir_config, &proxy_scgi_module); + if (conf->sendfile && conf->sendfile != scgi_sendfile_off) { + short err = 1; + + location = apr_table_get(r->err_headers_out, conf->sendfile); + if (!location) { + err = 0; + location = apr_table_get(r->headers_out, conf->sendfile); + } + if (location) { + scgi_request_config *req_conf = apr_palloc(r->pool, + sizeof(*req_conf)); + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00861) + "Found %s: %s - preparing subrequest.", + conf->sendfile, location); + + if (err) { + apr_table_unset(r->err_headers_out, conf->sendfile); + } + else { + apr_table_unset(r->headers_out, conf->sendfile); + } + req_conf->location = location; + req_conf->type = scgi_sendfile; + ap_set_module_config(r->request_config, &proxy_scgi_module, + req_conf); + apr_brigade_destroy(bb); + return OK; + } + } + + if (r->status == HTTP_OK + && (!conf->internal_redirect /* default === On */ + || conf->internal_redirect != scgi_internal_redirect_off)) { + short err = 1; + const char *location_header = conf->internal_redirect ? + conf->internal_redirect : scgi_internal_redirect_on; + + location = apr_table_get(r->err_headers_out, location_header); + if (!location) { + err = 0; + location = apr_table_get(r->headers_out, location_header); + } + if (location && *location == '/') { + scgi_request_config *req_conf = apr_palloc(r->pool, + sizeof(*req_conf)); + if (strcasecmp(location_header, "Location")) { + if (err) { + apr_table_unset(r->err_headers_out, location_header); + } + else { + apr_table_unset(r->headers_out, location_header); + } + } + req_conf->location = location; + req_conf->type = scgi_internal_redirect; + ap_set_module_config(r->request_config, &proxy_scgi_module, + req_conf); + apr_brigade_destroy(bb); + return OK; + } + } + + if (ap_pass_brigade(r->output_filters, bb)) { + return AP_FILTER_ERROR; + } + + return OK; +} + +/* + * Internal redirect / subrequest handler, working on request_status hook + */ +static int scgi_request_status(int *status, request_rec *r) +{ + scgi_request_config *req_conf; + + if ( (*status == OK) + && (req_conf = ap_get_module_config(r->request_config, + &proxy_scgi_module))) { + switch (req_conf->type) { + case scgi_internal_redirect: + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00862) + "Internal redirect to %s", req_conf->location); + + r->status_line = NULL; + if (r->method_number != M_GET) { + /* keep HEAD, which is passed around as M_GET, too */ + r->method = "GET"; + r->method_number = M_GET; + } + apr_table_unset(r->headers_in, "Content-Length"); + ap_internal_redirect_handler(req_conf->location, r); + return OK; + /* break; */ + + case scgi_sendfile: + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00863) + "File subrequest to %s", req_conf->location); + do { + request_rec *rr; + + rr = ap_sub_req_lookup_file(req_conf->location, r, + r->output_filters); + if (rr->status == HTTP_OK && rr->finfo.filetype != APR_NOFILE) { + /* + * We don't touch Content-Length here. It might be + * borked (there's plenty of room for a race condition). + * Either the backend sets it or it's gonna be chunked. + */ + ap_run_sub_req(rr); + } + else { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00864) + "Subrequest to file '%s' not possible. " + "(rr->status=%d, rr->finfo.filetype=%d)", + req_conf->location, rr->status, + rr->finfo.filetype); + *status = HTTP_INTERNAL_SERVER_ERROR; + return *status; + } + } while (0); + + return OK; + /* break; */ + } + } + + return DECLINED; +} + + +/* + * This handles scgi:(dest) URLs + */ +static int scgi_handler(request_rec *r, proxy_worker *worker, + proxy_server_conf *conf, char *url, + const char *proxyname, apr_port_t proxyport) +{ + int status; + proxy_conn_rec *backend = NULL; + apr_pool_t *p = r->pool; + apr_uri_t *uri; + char dummy; + + if (strncasecmp(url, SCHEME "://", sizeof(SCHEME) + 2)) { + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00865) + "declining URL %s", url); + return DECLINED; + } + + /* Create space for state information */ + status = ap_proxy_acquire_connection(PROXY_FUNCTION, &backend, worker, + r->server); + if (status != OK) { + goto cleanup; + } + backend->is_ssl = 0; + + /* Step One: Determine Who To Connect To */ + uri = apr_palloc(p, sizeof(*uri)); + status = ap_proxy_determine_connection(p, r, conf, worker, backend, + uri, &url, proxyname, proxyport, + &dummy, 1); + if (status != OK) { + goto cleanup; + } + + /* Step Two: Make the Connection */ + if (ap_proxy_connect_backend(PROXY_FUNCTION, backend, worker, r->server)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00866) + "failed to make connection to backend: %s:%u", + backend->hostname, backend->port); + status = HTTP_SERVICE_UNAVAILABLE; + goto cleanup; + } + + /* Step Three: Process the Request */ + if ( ((status = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR)) != OK) + || ((status = send_headers(r, backend)) != OK) + || ((status = send_request_body(r, backend)) != OK) + || ((status = pass_response(r, backend)) != OK)) { + goto cleanup; + } + +cleanup: + if (backend) { + backend->close = 1; /* always close the socket */ + ap_proxy_release_connection(PROXY_FUNCTION, backend, r->server); + } + return status; +} + + +static void *create_scgi_config(apr_pool_t *p, char *dummy) +{ + scgi_config *conf=apr_palloc(p, sizeof(*conf)); + + conf->sendfile = NULL; /* === default (off) */ + conf->internal_redirect = NULL; /* === default (on) */ + + return conf; +} + + +static void *merge_scgi_config(apr_pool_t *p, void *base_, void *add_) +{ + scgi_config *base=base_, *add=add_, *conf=apr_palloc(p, sizeof(*conf)); + + conf->sendfile = add->sendfile ? add->sendfile: base->sendfile; + conf->internal_redirect = add->internal_redirect + ? add->internal_redirect + : base->internal_redirect; + return conf; +} + + +static const char *scgi_set_send_file(cmd_parms *cmd, void *mconfig, + const char *arg) +{ + scgi_config *conf=mconfig; + + if (!strcasecmp(arg, "Off")) { + conf->sendfile = scgi_sendfile_off; + } + else if (!strcasecmp(arg, "On")) { + conf->sendfile = scgi_sendfile_on; + } + else { + conf->sendfile = arg; + } + return NULL; +} + + +static const char *scgi_set_internal_redirect(cmd_parms *cmd, void *mconfig, + const char *arg) +{ + scgi_config *conf = mconfig; + + if (!strcasecmp(arg, "Off")) { + conf->internal_redirect = scgi_internal_redirect_off; + } + else if (!strcasecmp(arg, "On")) { + conf->internal_redirect = scgi_internal_redirect_on; + } + else { + conf->internal_redirect = arg; + } + return NULL; +} + + +static const command_rec scgi_cmds[] = +{ + AP_INIT_TAKE1("ProxySCGISendfile", scgi_set_send_file, NULL, + RSRC_CONF|ACCESS_CONF, + "The name of the X-Sendfile pseudo response header or " + "On or Off"), + AP_INIT_TAKE1("ProxySCGIInternalRedirect", scgi_set_internal_redirect, NULL, + RSRC_CONF|ACCESS_CONF, + "The name of the pseudo response header or On or Off"), + {NULL} +}; + + +static void register_hooks(apr_pool_t *p) +{ + proxy_hook_scheme_handler(scgi_handler, NULL, NULL, APR_HOOK_FIRST); + proxy_hook_canon_handler(scgi_canon, NULL, NULL, APR_HOOK_FIRST); + APR_OPTIONAL_HOOK(proxy, request_status, scgi_request_status, NULL, NULL, + APR_HOOK_MIDDLE); +} + + +AP_DECLARE_MODULE(proxy_scgi) = { + STANDARD20_MODULE_STUFF, + create_scgi_config, /* create per-directory config structure */ + merge_scgi_config, /* merge per-directory config structures */ + NULL, /* create per-server config structure */ + NULL, /* merge per-server config structures */ + scgi_cmds, /* command table */ + register_hooks /* register hooks */ +}; |