/* 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. */ /* HTTP routines for Apache proxy */ #include "mod_proxy.h" #include "ap_regex.h" module AP_MODULE_DECLARE_DATA proxy_http_module; static apr_status_t ap_proxy_http_cleanup(const char *scheme, request_rec *r, proxy_conn_rec *backend); /* * Canonicalise http-like URLs. * scheme is the scheme for the URL * url is the URL starting with the first '/' * def_port is the default port for this scheme. */ static int proxy_http_canon(request_rec *r, char *url) { char *host, *path, sport[7]; char *search = NULL; const char *err; const char *scheme; apr_port_t port, def_port; /* ap_port_of_scheme() */ if (strncasecmp(url, "http:", 5) == 0) { url += 5; scheme = "http"; } else if (strncasecmp(url, "https:", 6) == 0) { url += 6; scheme = "https"; } else { return DECLINED; } def_port = apr_uri_port_of_scheme(scheme); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: HTTP: canonicalising URL %s", url); /* do syntatic check. * We break the URL into host, port, path, search */ port = 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, "error parsing URL %s: %s", url, err); return HTTP_BAD_REQUEST; } /* * now parse path/search args, according to rfc1738: * process the path. * * In a reverse proxy, our URL has been processed, so canonicalise * unless proxy-nocanon is set to say it's raw * In a forward proxy, we have and MUST NOT MANGLE the original. */ switch (r->proxyreq) { default: /* wtf are we doing here? */ case PROXYREQ_REVERSE: if (apr_table_get(r->notes, "proxy-nocanon")) { path = url; /* this is the raw path */ } else { path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, 0, r->proxyreq); search = r->args; } break; case PROXYREQ_PROXY: path = url; break; } if (path == NULL) return HTTP_BAD_REQUEST; if (port != def_port) apr_snprintf(sport, sizeof(sport), ":%d", port); else sport[0] = '\0'; if (ap_strchr_c(host, ':')) { /* if literal IPv6 address */ host = apr_pstrcat(r->pool, "[", host, "]", NULL); } r->filename = apr_pstrcat(r->pool, "proxy:", scheme, "://", host, sport, "/", path, (search) ? "?" : "", (search) ? search : "", NULL); return OK; } /* Clear all connection-based headers from the incoming headers table */ typedef struct header_dptr { apr_pool_t *pool; apr_table_t *table; apr_time_t time; } header_dptr; static ap_regex_t *warn_rx; static int clean_warning_headers(void *data, const char *key, const char *val) { apr_table_t *headers = ((header_dptr*)data)->table; apr_pool_t *pool = ((header_dptr*)data)->pool; char *warning; char *date; apr_time_t warn_time; const int nmatch = 3; ap_regmatch_t pmatch[3]; if (headers == NULL) { ((header_dptr*)data)->table = headers = apr_table_make(pool, 2); } /* * Parse this, suckers! * * Warning = "Warning" ":" 1#warning-value * * warning-value = warn-code SP warn-agent SP warn-text * [SP warn-date] * * warn-code = 3DIGIT * warn-agent = ( host [ ":" port ] ) | pseudonym * ; the name or pseudonym of the server adding * ; the Warning header, for use in debugging * warn-text = quoted-string * warn-date = <"> HTTP-date <"> * * Buggrit, use a bloomin' regexp! * (\d{3}\s+\S+\s+\".*?\"(\s+\"(.*?)\")?) --> whole in $1, date in $3 */ while (!ap_regexec(warn_rx, val, nmatch, pmatch, 0)) { warning = apr_pstrndup(pool, val+pmatch[0].rm_so, pmatch[0].rm_eo - pmatch[0].rm_so); warn_time = 0; if (pmatch[2].rm_eo > pmatch[2].rm_so) { /* OK, we have a date here */ date = apr_pstrndup(pool, val+pmatch[2].rm_so, pmatch[2].rm_eo - pmatch[2].rm_so); warn_time = apr_date_parse_http(date); } if (!warn_time || (warn_time == ((header_dptr*)data)->time)) { apr_table_addn(headers, key, warning); } val += pmatch[0].rm_eo; } return 1; } static apr_table_t *ap_proxy_clean_warnings(apr_pool_t *p, apr_table_t *headers) { header_dptr x; x.pool = p; x.table = NULL; x.time = apr_date_parse_http(apr_table_get(headers, "Date")); apr_table_do(clean_warning_headers, &x, headers, "Warning", NULL); if (x.table != NULL) { apr_table_unset(headers, "Warning"); return apr_table_overlay(p, headers, x.table); } else { return headers; } } static int clear_conn_headers(void *data, const char *key, const char *val) { apr_table_t *headers = ((header_dptr*)data)->table; apr_pool_t *pool = ((header_dptr*)data)->pool; const char *name; char *next = apr_pstrdup(pool, val); while (*next) { name = next; while (*next && !apr_isspace(*next) && (*next != ',')) { ++next; } while (*next && (apr_isspace(*next) || (*next == ','))) { *next++ = '\0'; } apr_table_unset(headers, name); } return 1; } static void ap_proxy_clear_connection(apr_pool_t *p, apr_table_t *headers) { header_dptr x; x.pool = p; x.table = headers; apr_table_unset(headers, "Proxy-Connection"); apr_table_do(clear_conn_headers, &x, headers, "Connection", NULL); apr_table_unset(headers, "Connection"); } static void add_te_chunked(apr_pool_t *p, apr_bucket_alloc_t *bucket_alloc, apr_bucket_brigade *header_brigade) { apr_bucket *e; char *buf; const char te_hdr[] = "Transfer-Encoding: chunked" CRLF; buf = apr_pmemdup(p, te_hdr, sizeof(te_hdr)-1); ap_xlate_proto_to_ascii(buf, sizeof(te_hdr)-1); e = apr_bucket_pool_create(buf, sizeof(te_hdr)-1, p, bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); } static void add_cl(apr_pool_t *p, apr_bucket_alloc_t *bucket_alloc, apr_bucket_brigade *header_brigade, const char *cl_val) { apr_bucket *e; char *buf; buf = apr_pstrcat(p, "Content-Length: ", cl_val, CRLF, NULL); ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), p, bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); } #define ASCII_CRLF "\015\012" #define ASCII_ZERO "\060" static void terminate_headers(apr_bucket_alloc_t *bucket_alloc, apr_bucket_brigade *header_brigade) { apr_bucket *e; /* add empty line at the end of the headers */ e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); } static int pass_brigade(apr_bucket_alloc_t *bucket_alloc, request_rec *r, proxy_conn_rec *conn, conn_rec *origin, apr_bucket_brigade *bb, int flush) { apr_status_t status; apr_off_t transferred; if (flush) { apr_bucket *e = apr_bucket_flush_create(bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); } apr_brigade_length(bb, 0, &transferred); if (transferred != -1) conn->worker->s->transferred += transferred; status = ap_pass_brigade(origin->output_filters, bb); if (status != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: pass request body failed to %pI (%s)", conn->addr, conn->hostname); if (origin->aborted) { return APR_STATUS_IS_TIMEUP(status) ? HTTP_GATEWAY_TIME_OUT : HTTP_BAD_GATEWAY; } else { return HTTP_BAD_REQUEST; } } apr_brigade_cleanup(bb); return OK; } #define MAX_MEM_SPOOL 16384 static int stream_reqbody_chunked(apr_pool_t *p, request_rec *r, proxy_conn_rec *p_conn, conn_rec *origin, apr_bucket_brigade *header_brigade, apr_bucket_brigade *input_brigade) { int seen_eos = 0, rv = OK; apr_size_t hdr_len; apr_off_t bytes; apr_status_t status; apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc; apr_bucket_brigade *bb; apr_bucket *e; add_te_chunked(p, bucket_alloc, header_brigade); terminate_headers(bucket_alloc, header_brigade); while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade))) { char chunk_hdr[20]; /* must be here due to transient bucket. */ /* If this brigade contains EOS, either stop or remove it. */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) { seen_eos = 1; /* We can't pass this EOS to the output_filters. */ e = APR_BRIGADE_LAST(input_brigade); apr_bucket_delete(e); } apr_brigade_length(input_brigade, 1, &bytes); hdr_len = apr_snprintf(chunk_hdr, sizeof(chunk_hdr), "%" APR_UINT64_T_HEX_FMT CRLF, (apr_uint64_t)bytes); ap_xlate_proto_to_ascii(chunk_hdr, hdr_len); e = apr_bucket_transient_create(chunk_hdr, hdr_len, bucket_alloc); APR_BRIGADE_INSERT_HEAD(input_brigade, e); /* * Append the end-of-chunk CRLF */ e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc); APR_BRIGADE_INSERT_TAIL(input_brigade, e); if (header_brigade) { /* we never sent the header brigade, so go ahead and * take care of that now */ bb = header_brigade; /* * Save input_brigade in bb brigade. (At least) in the SSL case * input_brigade contains transient buckets whose data would get * overwritten during the next call of ap_get_brigade in the loop. * ap_save_brigade ensures these buckets to be set aside. * Calling ap_save_brigade with NULL as filter is OK, because * bb brigade already has been created and does not need to get * created by ap_save_brigade. */ status = ap_save_brigade(NULL, &bb, &input_brigade, p); if (status != APR_SUCCESS) { return HTTP_INTERNAL_SERVER_ERROR; } header_brigade = NULL; } else { bb = input_brigade; } /* The request is flushed below this loop with chunk EOS header */ rv = pass_brigade(bucket_alloc, r, p_conn, origin, bb, 0); if (rv != OK) { return rv; } if (seen_eos) { break; } status = ap_get_brigade(r->input_filters, input_brigade, AP_MODE_READBYTES, APR_BLOCK_READ, HUGE_STRING_LEN); if (status != APR_SUCCESS) { return HTTP_BAD_REQUEST; } } if (header_brigade) { /* we never sent the header brigade because there was no request body; * send it now */ bb = header_brigade; } else { if (!APR_BRIGADE_EMPTY(input_brigade)) { /* input brigade still has an EOS which we can't pass to the output_filters. */ e = APR_BRIGADE_LAST(input_brigade); AP_DEBUG_ASSERT(APR_BUCKET_IS_EOS(e)); apr_bucket_delete(e); } bb = input_brigade; } e = apr_bucket_immortal_create(ASCII_ZERO ASCII_CRLF /* <trailers> */ ASCII_CRLF, 5, bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); /* Now we have headers-only, or the chunk EOS mark; flush it */ rv = pass_brigade(bucket_alloc, r, p_conn, origin, bb, 1); return rv; } static int stream_reqbody_cl(apr_pool_t *p, request_rec *r, proxy_conn_rec *p_conn, conn_rec *origin, apr_bucket_brigade *header_brigade, apr_bucket_brigade *input_brigade, const char *old_cl_val) { int seen_eos = 0, rv = 0; apr_status_t status = APR_SUCCESS; apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc; apr_bucket_brigade *bb; apr_bucket *e; apr_off_t cl_val = 0; apr_off_t bytes; apr_off_t bytes_streamed = 0; if (old_cl_val) { add_cl(p, bucket_alloc, header_brigade, old_cl_val); if (APR_SUCCESS != (status = apr_strtoff(&cl_val, old_cl_val, NULL, 0))) { return HTTP_INTERNAL_SERVER_ERROR; } } terminate_headers(bucket_alloc, header_brigade); while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade))) { apr_brigade_length(input_brigade, 1, &bytes); bytes_streamed += bytes; /* If this brigade contains EOS, either stop or remove it. */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) { seen_eos = 1; /* We can't pass this EOS to the output_filters. */ e = APR_BRIGADE_LAST(input_brigade); apr_bucket_delete(e); } /* C-L < bytes streamed?!? * We will error out after the body is completely * consumed, but we can't stream more bytes at the * back end since they would in part be interpreted * as another request! If nothing is sent, then * just send nothing. * * Prevents HTTP Response Splitting. */ if (bytes_streamed > cl_val) continue; if (header_brigade) { /* we never sent the header brigade, so go ahead and * take care of that now */ bb = header_brigade; /* * Save input_brigade in bb brigade. (At least) in the SSL case * input_brigade contains transient buckets whose data would get * overwritten during the next call of ap_get_brigade in the loop. * ap_save_brigade ensures these buckets to be set aside. * Calling ap_save_brigade with NULL as filter is OK, because * bb brigade already has been created and does not need to get * created by ap_save_brigade. */ status = ap_save_brigade(NULL, &bb, &input_brigade, p); if (status != APR_SUCCESS) { return HTTP_INTERNAL_SERVER_ERROR; } header_brigade = NULL; } else { bb = input_brigade; } /* Once we hit EOS, we are ready to flush. */ rv = pass_brigade(bucket_alloc, r, p_conn, origin, bb, seen_eos); if (rv != OK) { return rv ; } if (seen_eos) { break; } status = ap_get_brigade(r->input_filters, input_brigade, AP_MODE_READBYTES, APR_BLOCK_READ, HUGE_STRING_LEN); if (status != APR_SUCCESS) { return HTTP_BAD_REQUEST; } } if (bytes_streamed != cl_val) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, "proxy: client %s given Content-Length did not match" " number of body bytes read", r->connection->remote_ip); return HTTP_BAD_REQUEST; } if (header_brigade) { /* we never sent the header brigade since there was no request * body; send it now with the flush flag */ bb = header_brigade; return(pass_brigade(bucket_alloc, r, p_conn, origin, bb, 1)); } return OK; } static int spool_reqbody_cl(apr_pool_t *p, request_rec *r, proxy_conn_rec *p_conn, conn_rec *origin, apr_bucket_brigade *header_brigade, apr_bucket_brigade *input_brigade, int force_cl) { int seen_eos = 0; apr_status_t status; apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc; apr_bucket_brigade *body_brigade; apr_bucket *e; apr_off_t bytes, bytes_spooled = 0, fsize = 0; apr_file_t *tmpfile = NULL; body_brigade = apr_brigade_create(p, bucket_alloc); while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade))) { /* If this brigade contains EOS, either stop or remove it. */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) { seen_eos = 1; /* We can't pass this EOS to the output_filters. */ e = APR_BRIGADE_LAST(input_brigade); apr_bucket_delete(e); } apr_brigade_length(input_brigade, 1, &bytes); if (bytes_spooled + bytes > MAX_MEM_SPOOL) { /* can't spool any more in memory; write latest brigade to disk */ if (tmpfile == NULL) { const char *temp_dir; char *template; status = apr_temp_dir_get(&temp_dir, p); if (status != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: search for temporary directory failed"); return HTTP_INTERNAL_SERVER_ERROR; } apr_filepath_merge(&template, temp_dir, "modproxy.tmp.XXXXXX", APR_FILEPATH_NATIVE, p); status = apr_file_mktemp(&tmpfile, template, 0, p); if (status != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: creation of temporary file in directory %s failed", temp_dir); return HTTP_INTERNAL_SERVER_ERROR; } } for (e = APR_BRIGADE_FIRST(input_brigade); e != APR_BRIGADE_SENTINEL(input_brigade); e = APR_BUCKET_NEXT(e)) { const char *data; apr_size_t bytes_read, bytes_written; apr_bucket_read(e, &data, &bytes_read, APR_BLOCK_READ); status = apr_file_write_full(tmpfile, data, bytes_read, &bytes_written); if (status != APR_SUCCESS) { const char *tmpfile_name; if (apr_file_name_get(&tmpfile_name, tmpfile) != APR_SUCCESS) { tmpfile_name = "(unknown)"; } ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: write to temporary file %s failed", tmpfile_name); return HTTP_INTERNAL_SERVER_ERROR; } AP_DEBUG_ASSERT(bytes_read == bytes_written); fsize += bytes_written; } apr_brigade_cleanup(input_brigade); } else { /* * Save input_brigade in body_brigade. (At least) in the SSL case * input_brigade contains transient buckets whose data would get * overwritten during the next call of ap_get_brigade in the loop. * ap_save_brigade ensures these buckets to be set aside. * Calling ap_save_brigade with NULL as filter is OK, because * body_brigade already has been created and does not need to get * created by ap_save_brigade. */ status = ap_save_brigade(NULL, &body_brigade, &input_brigade, p); if (status != APR_SUCCESS) { return HTTP_INTERNAL_SERVER_ERROR; } } bytes_spooled += bytes; if (seen_eos) { break; } status = ap_get_brigade(r->input_filters, input_brigade, AP_MODE_READBYTES, APR_BLOCK_READ, HUGE_STRING_LEN); if (status != APR_SUCCESS) { return HTTP_BAD_REQUEST; } } if (bytes_spooled || force_cl) { add_cl(p, bucket_alloc, header_brigade, apr_off_t_toa(p, bytes_spooled)); } terminate_headers(bucket_alloc, header_brigade); APR_BRIGADE_CONCAT(header_brigade, body_brigade); if (tmpfile) { /* For platforms where the size of the file may be larger than * that which can be stored in a single bucket (where the * length field is an apr_size_t), split it into several * buckets: */ if (sizeof(apr_off_t) > sizeof(apr_size_t) && fsize > AP_MAX_SENDFILE) { e = apr_bucket_file_create(tmpfile, 0, AP_MAX_SENDFILE, p, bucket_alloc); while (fsize > AP_MAX_SENDFILE) { apr_bucket *ce; apr_bucket_copy(e, &ce); APR_BRIGADE_INSERT_TAIL(header_brigade, ce); e->start += AP_MAX_SENDFILE; fsize -= AP_MAX_SENDFILE; } e->length = (apr_size_t)fsize; /* Resize just the last bucket */ } else { e = apr_bucket_file_create(tmpfile, 0, (apr_size_t)fsize, p, bucket_alloc); } APR_BRIGADE_INSERT_TAIL(header_brigade, e); } /* This is all a single brigade, pass with flush flagged */ return(pass_brigade(bucket_alloc, r, p_conn, origin, header_brigade, 1)); } static int ap_proxy_http_request(apr_pool_t *p, request_rec *r, proxy_conn_rec *p_conn, conn_rec *origin, proxy_server_conf *conf, apr_uri_t *uri, char *url, char *server_portstr) { conn_rec *c = r->connection; apr_bucket_alloc_t *bucket_alloc = c->bucket_alloc; apr_bucket_brigade *header_brigade; apr_bucket_brigade *input_brigade; apr_bucket_brigade *temp_brigade; apr_bucket *e; char *buf; const apr_array_header_t *headers_in_array; const apr_table_entry_t *headers_in; int counter; apr_status_t status; enum rb_methods {RB_INIT, RB_STREAM_CL, RB_STREAM_CHUNKED, RB_SPOOL_CL}; enum rb_methods rb_method = RB_INIT; const char *old_cl_val = NULL; const char *old_te_val = NULL; apr_off_t bytes_read = 0; apr_off_t bytes; int force10, rv; apr_table_t *headers_in_copy; header_brigade = apr_brigade_create(p, origin->bucket_alloc); /* * Send the HTTP/1.1 request to the remote server */ if (apr_table_get(r->subprocess_env, "force-proxy-request-1.0")) { buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.0" CRLF, NULL); force10 = 1; /* * According to RFC 2616 8.2.3 we are not allowed to forward an * Expect: 100-continue to an HTTP/1.0 server. Instead we MUST return * a HTTP_EXPECTATION_FAILED */ if (r->expecting_100) { return HTTP_EXPECTATION_FAILED; } p_conn->close++; } else { buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.1" CRLF, NULL); force10 = 0; } if (apr_table_get(r->subprocess_env, "proxy-nokeepalive")) { origin->keepalive = AP_CONN_CLOSE; p_conn->close++; } ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); if (conf->preserve_host == 0) { if (uri->port_str && uri->port != DEFAULT_HTTP_PORT) { buf = apr_pstrcat(p, "Host: ", uri->hostname, ":", uri->port_str, CRLF, NULL); } else { buf = apr_pstrcat(p, "Host: ", uri->hostname, CRLF, NULL); } } else { /* don't want to use r->hostname, as the incoming header might have a * port attached */ const char* hostname = apr_table_get(r->headers_in,"Host"); if (!hostname) { hostname = r->server->server_hostname; ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, "proxy: no HTTP 0.9 request (with no host line) " "on incoming request and preserve host set " "forcing hostname to be %s for uri %s", hostname, r->uri ); } buf = apr_pstrcat(p, "Host: ", hostname, CRLF, NULL); } ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); /* handle Via */ if (conf->viaopt == via_block) { /* Block all outgoing Via: headers */ apr_table_unset(r->headers_in, "Via"); } else if (conf->viaopt != via_off) { const char *server_name = ap_get_server_name(r); /* If USE_CANONICAL_NAME_OFF was configured for the proxy virtual host, * then the server name returned by ap_get_server_name() is the * origin server name (which does make too much sense with Via: headers) * so we use the proxy vhost's name instead. */ if (server_name == r->hostname) server_name = r->server->server_hostname; /* Create a "Via:" request header entry and merge it */ /* Generate outgoing Via: header with/without server comment: */ apr_table_mergen(r->headers_in, "Via", (conf->viaopt == via_full) ? apr_psprintf(p, "%d.%d %s%s (%s)", HTTP_VERSION_MAJOR(r->proto_num), HTTP_VERSION_MINOR(r->proto_num), server_name, server_portstr, AP_SERVER_BASEVERSION) : apr_psprintf(p, "%d.%d %s%s", HTTP_VERSION_MAJOR(r->proto_num), HTTP_VERSION_MINOR(r->proto_num), server_name, server_portstr) ); } /* X-Forwarded-*: handling * * XXX Privacy Note: * ----------------- * * These request headers are only really useful when the mod_proxy * is used in a reverse proxy configuration, so that useful info * about the client can be passed through the reverse proxy and on * to the backend server, which may require the information to * function properly. * * In a forward proxy situation, these options are a potential * privacy violation, as information about clients behind the proxy * are revealed to arbitrary servers out there on the internet. * * The HTTP/1.1 Via: header is designed for passing client * information through proxies to a server, and should be used in * a forward proxy configuation instead of X-Forwarded-*. See the * ProxyVia option for details. */ if (PROXYREQ_REVERSE == r->proxyreq) { const char *buf; /* Add X-Forwarded-For: so that the upstream has a chance to * determine, where the original request came from. */ apr_table_mergen(r->headers_in, "X-Forwarded-For", c->remote_ip); /* Add X-Forwarded-Host: so that upstream knows what the * original request hostname was. */ if ((buf = apr_table_get(r->headers_in, "Host"))) { apr_table_mergen(r->headers_in, "X-Forwarded-Host", buf); } /* Add X-Forwarded-Server: so that upstream knows what the * name of this proxy server is (if there are more than one) * XXX: This duplicates Via: - do we strictly need it? */ apr_table_mergen(r->headers_in, "X-Forwarded-Server", r->server->server_hostname); } proxy_run_fixups(r); /* * Make a copy of the headers_in table before clearing the connection * headers as we need the connection headers later in the http output * filter to prepare the correct response headers. * * Note: We need to take r->pool for apr_table_copy as the key / value * pairs in r->headers_in have been created out of r->pool and * p might be (and actually is) a longer living pool. * This would trigger the bad pool ancestry abort in apr_table_copy if * apr is compiled with APR_POOL_DEBUG. */ headers_in_copy = apr_table_copy(r->pool, r->headers_in); ap_proxy_clear_connection(p, headers_in_copy); /* send request headers */ headers_in_array = apr_table_elts(headers_in_copy); headers_in = (const apr_table_entry_t *) headers_in_array->elts; for (counter = 0; counter < headers_in_array->nelts; counter++) { if (headers_in[counter].key == NULL || headers_in[counter].val == NULL /* Already sent */ || !strcasecmp(headers_in[counter].key, "Host") /* Clear out hop-by-hop request headers not to send * RFC2616 13.5.1 says we should strip these headers */ || !strcasecmp(headers_in[counter].key, "Keep-Alive") || !strcasecmp(headers_in[counter].key, "TE") || !strcasecmp(headers_in[counter].key, "Trailer") || !strcasecmp(headers_in[counter].key, "Upgrade") ) { continue; } /* Do we want to strip Proxy-Authorization ? * If we haven't used it, then NO * If we have used it then MAYBE: RFC2616 says we MAY propagate it. * So let's make it configurable by env. */ if (!strcasecmp(headers_in[counter].key,"Proxy-Authorization")) { if (r->user != NULL) { /* we've authenticated */ if (!apr_table_get(r->subprocess_env, "Proxy-Chain-Auth")) { continue; } } } /* Skip Transfer-Encoding and Content-Length for now. */ if (!strcasecmp(headers_in[counter].key, "Transfer-Encoding")) { old_te_val = headers_in[counter].val; continue; } if (!strcasecmp(headers_in[counter].key, "Content-Length")) { old_cl_val = headers_in[counter].val; continue; } /* for sub-requests, ignore freshness/expiry headers */ if (r->main) { if ( !strcasecmp(headers_in[counter].key, "If-Match") || !strcasecmp(headers_in[counter].key, "If-Modified-Since") || !strcasecmp(headers_in[counter].key, "If-Range") || !strcasecmp(headers_in[counter].key, "If-Unmodified-Since") || !strcasecmp(headers_in[counter].key, "If-None-Match")) { continue; } } buf = apr_pstrcat(p, headers_in[counter].key, ": ", headers_in[counter].val, CRLF, NULL); ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); } /* We have headers, let's figure out our request body... */ input_brigade = apr_brigade_create(p, bucket_alloc); /* sub-requests never use keepalives, and mustn't pass request bodies. * Because the new logic looks at input_brigade, we will self-terminate * input_brigade and jump past all of the request body logic... * Reading anything with ap_get_brigade is likely to consume the * main request's body or read beyond EOS - which would be unplesant. */ if (r->main) { /* XXX: Why DON'T sub-requests use keepalives? */ p_conn->close++; if (old_cl_val) { old_cl_val = NULL; apr_table_unset(r->headers_in, "Content-Length"); } if (old_te_val) { old_te_val = NULL; apr_table_unset(r->headers_in, "Transfer-Encoding"); } rb_method = RB_STREAM_CL; e = apr_bucket_eos_create(input_brigade->bucket_alloc); APR_BRIGADE_INSERT_TAIL(input_brigade, e); goto skip_body; } /* WE only understand chunked. Other modules might inject * (and therefore, decode) other flavors but we don't know * that the can and have done so unless they they remove * their decoding from the headers_in T-E list. * XXX: Make this extensible, but in doing so, presume the * encoding has been done by the extensions' handler, and * do not modify add_te_chunked's logic */ if (old_te_val && strcmp(old_te_val, "chunked") != 0) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, "proxy: %s Transfer-Encoding is not supported", old_te_val); return HTTP_INTERNAL_SERVER_ERROR; } if (old_cl_val && old_te_val) { ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_ENOTIMPL, r->server, "proxy: client %s (%s) requested Transfer-Encoding " "chunked body with Content-Length (C-L ignored)", c->remote_ip, c->remote_host ? c->remote_host: ""); apr_table_unset(r->headers_in, "Content-Length"); old_cl_val = NULL; origin->keepalive = AP_CONN_CLOSE; p_conn->close++; } /* Prefetch MAX_MEM_SPOOL bytes * * This helps us avoid any election of C-L v.s. T-E * request bodies, since we are willing to keep in * memory this much data, in any case. This gives * us an instant C-L election if the body is of some * reasonable size. */ temp_brigade = apr_brigade_create(p, bucket_alloc); do { status = ap_get_brigade(r->input_filters, temp_brigade, AP_MODE_READBYTES, APR_BLOCK_READ, MAX_MEM_SPOOL - bytes_read); if (status != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: prefetch request body failed to %pI (%s)" " from %s (%s)", p_conn->addr, p_conn->hostname ? p_conn->hostname: "", c->remote_ip, c->remote_host ? c->remote_host: ""); return HTTP_BAD_REQUEST; } apr_brigade_length(temp_brigade, 1, &bytes); bytes_read += bytes; /* * Save temp_brigade in input_brigade. (At least) in the SSL case * temp_brigade contains transient buckets whose data would get * overwritten during the next call of ap_get_brigade in the loop. * ap_save_brigade ensures these buckets to be set aside. * Calling ap_save_brigade with NULL as filter is OK, because * input_brigade already has been created and does not need to get * created by ap_save_brigade. */ status = ap_save_brigade(NULL, &input_brigade, &temp_brigade, p); if (status != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server, "proxy: processing prefetched request body failed" " to %pI (%s) from %s (%s)", p_conn->addr, p_conn->hostname ? p_conn->hostname: "", c->remote_ip, c->remote_host ? c->remote_host: ""); return HTTP_INTERNAL_SERVER_ERROR; } /* Ensure we don't hit a wall where we have a buffer too small * for ap_get_brigade's filters to fetch us another bucket, * surrender once we hit 80 bytes less than MAX_MEM_SPOOL * (an arbitrary value.) */ } while ((bytes_read < MAX_MEM_SPOOL - 80) && !APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))); /* Use chunked request body encoding or send a content-length body? * * Prefer C-L when: * * We have no request body (handled by RB_STREAM_CL) * * We have a request body length <= MAX_MEM_SPOOL * * The administrator has setenv force-proxy-request-1.0 * * The client sent a C-L body, and the administrator has * not setenv proxy-sendchunked or has set setenv proxy-sendcl * * The client sent a T-E body, and the administrator has * setenv proxy-sendcl, and not setenv proxy-sendchunked * * If both proxy-sendcl and proxy-sendchunked are set, the * behavior is the same as if neither were set, large bodies * that can't be read will be forwarded in their original * form of C-L, or T-E. * * To ensure maximum compatibility, setenv proxy-sendcl * To reduce server resource use, setenv proxy-sendchunked * * Then address specific servers with conditional setenv * options to restore the default behavior where desireable. * * We have to compute content length by reading the entire request * body; if request body is not small, we'll spool the remaining * input to a temporary file. Chunked is always preferable. * * We can only trust the client-provided C-L if the T-E header * is absent, and the filters are unchanged (the body won't * be resized by another content filter). */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) { /* The whole thing fit, so our decision is trivial, use * the filtered bytes read from the client for the request * body Content-Length. * * If we expected no body, and read no body, do not set * the Content-Length. */ if (old_cl_val || old_te_val || bytes_read) { old_cl_val = apr_off_t_toa(r->pool, bytes_read); } rb_method = RB_STREAM_CL; } else if (old_te_val) { if (force10 || (apr_table_get(r->subprocess_env, "proxy-sendcl") && !apr_table_get(r->subprocess_env, "proxy-sendchunks") && !apr_table_get(r->subprocess_env, "proxy-sendchunked"))) { rb_method = RB_SPOOL_CL; } else { rb_method = RB_STREAM_CHUNKED; } } else if (old_cl_val) { if (r->input_filters == r->proto_input_filters) { rb_method = RB_STREAM_CL; } else if (!force10 && (apr_table_get(r->subprocess_env, "proxy-sendchunks") || apr_table_get(r->subprocess_env, "proxy-sendchunked")) && !apr_table_get(r->subprocess_env, "proxy-sendcl")) { rb_method = RB_STREAM_CHUNKED; } else { rb_method = RB_SPOOL_CL; } } else { /* This is an appropriate default; very efficient for no-body * requests, and has the behavior that it will not add any C-L * when the old_cl_val is NULL. */ rb_method = RB_SPOOL_CL; } /* Yes I hate gotos. This is the subrequest shortcut */ skip_body: /* * Handle Connection: header if we do HTTP/1.1 request: * If we plan to close the backend connection sent Connection: close * otherwise sent Connection: Keep-Alive. */ if (!force10) { if (p_conn->close || p_conn->close_on_recycle) { buf = apr_pstrdup(p, "Connection: close" CRLF); } else { buf = apr_pstrdup(p, "Connection: Keep-Alive" CRLF); } ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(header_brigade, e); } /* send the request body, if any. */ switch(rb_method) { case RB_STREAM_CHUNKED: rv = stream_reqbody_chunked(p, r, p_conn, origin, header_brigade, input_brigade); break; case RB_STREAM_CL: rv = stream_reqbody_cl(p, r, p_conn, origin, header_brigade, input_brigade, old_cl_val); break; case RB_SPOOL_CL: rv = spool_reqbody_cl(p, r, p_conn, origin, header_brigade, input_brigade, (old_cl_val != NULL) || (old_te_val != NULL) || (bytes_read > 0)); break; default: /* shouldn't be possible */ rv = HTTP_INTERNAL_SERVER_ERROR ; break; } if (rv != OK) { /* apr_errno value has been logged in lower level method */ ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, "proxy: pass request body failed to %pI (%s)" " from %s (%s)", p_conn->addr, p_conn->hostname ? p_conn->hostname: "", c->remote_ip, c->remote_host ? c->remote_host: ""); return rv; } return OK; } static void process_proxy_header(request_rec* r, proxy_dir_conf* c, const char* key, const char* value) { static const char* date_hdrs[] = { "Date", "Expires", "Last-Modified", NULL } ; static const struct { const char* name; ap_proxy_header_reverse_map_fn func; } transform_hdrs[] = { { "Location", ap_proxy_location_reverse_map } , { "Content-Location", ap_proxy_location_reverse_map } , { "URI", ap_proxy_location_reverse_map } , { "Destination", ap_proxy_location_reverse_map } , { "Set-Cookie", ap_proxy_cookie_reverse_map } , { NULL, NULL } } ; int i ; for ( i = 0 ; date_hdrs[i] ; ++i ) { if ( !strcasecmp(date_hdrs[i], key) ) { apr_table_add(r->headers_out, key, ap_proxy_date_canon(r->pool, value)) ; return ; } } for ( i = 0 ; transform_hdrs[i].name ; ++i ) { if ( !strcasecmp(transform_hdrs[i].name, key) ) { apr_table_add(r->headers_out, key, (*transform_hdrs[i].func)(r, c, value)) ; return ; } } apr_table_add(r->headers_out, key, value) ; return ; } /* * Note: pread_len is the length of the response that we've mistakenly * read (assuming that we don't consider that an error via * ProxyBadHeader StartBody). This depends on buffer actually being * local storage to the calling code in order for pread_len to make * any sense at all, since we depend on buffer still containing * what was read by ap_getline() upon return. */ static void ap_proxy_read_headers(request_rec *r, request_rec *rr, char *buffer, int size, conn_rec *c, int *pread_len) { int len; char *value, *end; char field[MAX_STRING_LEN]; int saw_headers = 0; void *sconf = r->server->module_config; proxy_server_conf *psc; proxy_dir_conf *dconf; dconf = ap_get_module_config(r->per_dir_config, &proxy_module); psc = (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module); r->headers_out = apr_table_make(r->pool, 20); *pread_len = 0; /* * Read header lines until we get the empty separator line, a read error, * the connection closes (EOF), or we timeout. */ while ((len = ap_getline(buffer, size, rr, 1)) > 0) { if (!(value = strchr(buffer, ':'))) { /* Find the colon separator */ /* We may encounter invalid headers, usually from buggy * MS IIS servers, so we need to determine just how to handle * them. We can either ignore them, assume that they mark the * start-of-body (eg: a missing CRLF) or (the default) mark * the headers as totally bogus and return a 500. The sole * exception is an extra "HTTP/1.0 200, OK" line sprinkled * in between the usual MIME headers, which is a favorite * IIS bug. */ /* XXX: The mask check is buggy if we ever see an HTTP/1.10 */ if (!apr_date_checkmask(buffer, "HTTP/#.# ###*")) { if (psc->badopt == bad_error) { /* Nope, it wasn't even an extra HTTP header. Give up. */ r->headers_out = NULL; return ; } else if (psc->badopt == bad_body) { /* if we've already started loading headers_out, then * return what we've accumulated so far, in the hopes * that they are useful; also note that we likely pre-read * the first line of the response. */ if (saw_headers) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server, "proxy: Starting body due to bogus non-header in headers " "returned by %s (%s)", r->uri, r->method); *pread_len = len; return ; } else { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server, "proxy: No HTTP headers " "returned by %s (%s)", r->uri, r->method); return ; } } } /* this is the psc->badopt == bad_ignore case */ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server, "proxy: Ignoring bogus HTTP header " "returned by %s (%s)", r->uri, r->method); continue; } *value = '\0'; ++value; /* XXX: RFC2068 defines only SP and HT as whitespace, this test is * wrong... and so are many others probably. */ while (apr_isspace(*value)) ++value; /* Skip to start of value */ /* should strip trailing whitespace as well */ for (end = &value[strlen(value)-1]; end > value && apr_isspace(*end); -- end) *end = '\0'; /* make sure we add so as not to destroy duplicated headers * Modify headers requiring canonicalisation and/or affected * by ProxyPassReverse and family with process_proxy_header */ process_proxy_header(r, dconf, buffer, value) ; saw_headers = 1; /* the header was too long; at the least we should skip extra data */ if (len >= size - 1) { while ((len = ap_getline(field, MAX_STRING_LEN, rr, 1)) >= MAX_STRING_LEN - 1) { /* soak up the extra data */ } if (len == 0) /* time to exit the larger loop as well */ break; } } } static int addit_dammit(void *v, const char *key, const char *val) { apr_table_addn(v, key, val); return 1; } static apr_status_t ap_proxygetline(apr_bucket_brigade *bb, char *s, int n, request_rec *r, int fold, int *writen) { char *tmp_s = s; apr_status_t rv; apr_size_t len; rv = ap_rgetline(&tmp_s, n, &len, r, fold, bb); apr_brigade_cleanup(bb); if (rv == APR_SUCCESS) { *writen = (int) len; } else if (rv == APR_ENOSPC) { *writen = n; } else { *writen = -1; } return rv; } /* * Limit the number of interim respones we sent back to the client. Otherwise * we suffer from a memory build up. Besides there is NO sense in sending back * an unlimited number of interim responses to the client. Thus if we cross * this limit send back a 502 (Bad Gateway). */ #ifndef AP_MAX_INTERIM_RESPONSES #define AP_MAX_INTERIM_RESPONSES 10 #endif static apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r, proxy_conn_rec *backend, conn_rec *origin, proxy_server_conf *conf, char *server_portstr) { conn_rec *c = r->connection; char buffer[HUGE_STRING_LEN]; const char *buf; char keepchar; request_rec *rp; apr_bucket *e; apr_bucket_brigade *bb, *tmp_bb; int len, backasswards; int interim_response = 0; /* non-zero whilst interim 1xx responses * are being read. */ int pread_len = 0; apr_table_t *save_table; int backend_broke = 0; static const char *hop_by_hop_hdrs[] = {"Keep-Alive", "Proxy-Authenticate", "TE", "Trailer", "Upgrade", NULL}; int i; const char *te = NULL; bb = apr_brigade_create(p, c->bucket_alloc); /* Get response from the remote server, and pass it up the * filter chain */ rp = ap_proxy_make_fake_req(origin, r); /* In case anyone needs to know, this is a fake request that is really a * response. */ rp->proxyreq = PROXYREQ_RESPONSE; tmp_bb = apr_brigade_create(p, c->bucket_alloc); do { apr_status_t rc; apr_brigade_cleanup(bb); rc = ap_proxygetline(tmp_bb, buffer, sizeof(buffer), rp, 0, &len); if (len == 0) { /* handle one potential stray CRLF */ rc = ap_proxygetline(tmp_bb, buffer, sizeof(buffer), rp, 0, &len); } if (len <= 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, rc, r, "proxy: error reading status line from remote " "server %s", backend->hostname); if (rc == APR_TIMEUP) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "proxy: read timeout"); } /* * If we are a reverse proxy request shutdown the connection * WITHOUT ANY response to trigger a retry by the client * if allowed (as for idempotent requests). * BUT currently we should not do this if the request is the * first request on a keepalive connection as browsers like * seamonkey only display an empty page in this case and do * not do a retry. We should also not do this on a * connection which times out; instead handle as * we normally would handle timeouts */ if (r->proxyreq == PROXYREQ_REVERSE && c->keepalives && rc != APR_TIMEUP) { apr_bucket *eos; ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "proxy: Closing connection to client because" " reading from backend server %s failed. Number" " of keepalives %i", backend->hostname, c->keepalives); ap_proxy_backend_broke(r, bb); /* * Add an EOC bucket to signal the ap_http_header_filter * that it should get out of our way, BUT ensure that the * EOC bucket is inserted BEFORE an EOS bucket in bb as * some resource filters like mod_deflate pass everything * up to the EOS down the chain immediately and sent the * remainder of the brigade later (or even never). But in * this case the ap_http_header_filter does not get out of * our way soon enough. */ e = ap_bucket_eoc_create(c->bucket_alloc); eos = APR_BRIGADE_LAST(bb); while ((APR_BRIGADE_SENTINEL(bb) != eos) && !APR_BUCKET_IS_EOS(eos)) { eos = APR_BUCKET_PREV(eos); } if (eos == APR_BRIGADE_SENTINEL(bb)) { APR_BRIGADE_INSERT_TAIL(bb, e); } else { APR_BUCKET_INSERT_BEFORE(eos, e); } ap_pass_brigade(r->output_filters, bb); /* Need to return OK to avoid sending an error message */ return OK; } else if (!c->keepalives) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "proxy: NOT Closing connection to client" " although reading from backend server %s" " failed.", backend->hostname); } return ap_proxyerror(r, HTTP_BAD_GATEWAY, "Error reading from remote server"); } /* XXX: Is this a real headers length send from remote? */ backend->worker->s->read += len; /* Is it an HTTP/1 response? * This is buggy if we ever see an HTTP/1.10 */ if (apr_date_checkmask(buffer, "HTTP/#.# ###*")) { int major, minor; if (2 != sscanf(buffer, "HTTP/%u.%u", &major, &minor)) { major = 1; minor = 1; } /* If not an HTTP/1 message or * if the status line was > 8192 bytes */ else if ((buffer[5] != '1') || (len >= sizeof(buffer)-1)) { return ap_proxyerror(r, HTTP_BAD_GATEWAY, apr_pstrcat(p, "Corrupt status line returned by remote " "server: ", buffer, NULL)); } backasswards = 0; keepchar = buffer[12]; buffer[12] = '\0'; r->status = atoi(&buffer[9]); if (keepchar != '\0') { buffer[12] = keepchar; } else { /* 2616 requires the space in Status-Line; the origin * server may have sent one but ap_rgetline_core will * have stripped it. */ buffer[12] = ' '; buffer[13] = '\0'; } r->status_line = apr_pstrdup(p, &buffer[9]); /* read the headers. */ /* N.B. for HTTP/1.0 clients, we have to fold line-wrapped headers*/ /* Also, take care with headers with multiple occurences. */ /* First, tuck away all already existing cookies */ save_table = apr_table_make(r->pool, 2); apr_table_do(addit_dammit, save_table, r->headers_out, "Set-Cookie", NULL); /* shove the headers direct into r->headers_out */ ap_proxy_read_headers(r, rp, buffer, sizeof(buffer), origin, &pread_len); if (r->headers_out == NULL) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server, "proxy: bad HTTP/%d.%d header " "returned by %s (%s)", major, minor, r->uri, r->method); backend->close += 1; /* * ap_send_error relies on a headers_out to be present. we * are in a bad position here.. so force everything we send out * to have nothing to do with the incoming packet */ r->headers_out = apr_table_make(r->pool,1); r->status = HTTP_BAD_GATEWAY; r->status_line = "bad gateway"; return r->status; } /* Now, add in the just read cookies */ apr_table_do(addit_dammit, save_table, r->headers_out, "Set-Cookie", NULL); /* and now load 'em all in */ if (!apr_is_empty_table(save_table)) { apr_table_unset(r->headers_out, "Set-Cookie"); r->headers_out = apr_table_overlay(r->pool, r->headers_out, save_table); } /* can't have both Content-Length and Transfer-Encoding */ if (apr_table_get(r->headers_out, "Transfer-Encoding") && apr_table_get(r->headers_out, "Content-Length")) { /* * 2616 section 4.4, point 3: "if both Transfer-Encoding * and Content-Length are received, the latter MUST be * ignored"; * * To help mitigate HTTP Splitting, unset Content-Length * and shut down the backend server connection * XXX: We aught to treat such a response as uncachable */ apr_table_unset(r->headers_out, "Content-Length"); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: server %s returned Transfer-Encoding" " and Content-Length", backend->hostname); backend->close += 1; } /* * Save a possible Transfer-Encoding header as we need it later for * ap_http_filter to know where to end. */ te = apr_table_get(r->headers_out, "Transfer-Encoding"); /* strip connection listed hop-by-hop headers from response */ backend->close += ap_proxy_liststr(apr_table_get(r->headers_out, "Connection"), "close"); ap_proxy_clear_connection(p, r->headers_out); if ((buf = apr_table_get(r->headers_out, "Content-Type"))) { ap_set_content_type(r, apr_pstrdup(p, buf)); } if (!ap_is_HTTP_INFO(r->status)) { ap_proxy_pre_http_request(origin, rp); } /* Clear hop-by-hop headers */ for (i=0; hop_by_hop_hdrs[i]; ++i) { apr_table_unset(r->headers_out, hop_by_hop_hdrs[i]); } /* Delete warnings with wrong date */ r->headers_out = ap_proxy_clean_warnings(p, r->headers_out); /* handle Via header in response */ if (conf->viaopt != via_off && conf->viaopt != via_block) { const char *server_name = ap_get_server_name(r); /* If USE_CANONICAL_NAME_OFF was configured for the proxy virtual host, * then the server name returned by ap_get_server_name() is the * origin server name (which does make too much sense with Via: headers) * so we use the proxy vhost's name instead. */ if (server_name == r->hostname) server_name = r->server->server_hostname; /* create a "Via:" response header entry and merge it */ apr_table_addn(r->headers_out, "Via", (conf->viaopt == via_full) ? apr_psprintf(p, "%d.%d %s%s (%s)", HTTP_VERSION_MAJOR(r->proto_num), HTTP_VERSION_MINOR(r->proto_num), server_name, server_portstr, AP_SERVER_BASEVERSION) : apr_psprintf(p, "%d.%d %s%s", HTTP_VERSION_MAJOR(r->proto_num), HTTP_VERSION_MINOR(r->proto_num), server_name, server_portstr) ); } /* cancel keepalive if HTTP/1.0 or less */ if ((major < 1) || (minor < 1)) { backend->close += 1; origin->keepalive = AP_CONN_CLOSE; } } else { /* an http/0.9 response */ backasswards = 1; r->status = 200; r->status_line = "200 OK"; backend->close += 1; } if (ap_is_HTTP_INFO(r->status)) { interim_response++; } else { interim_response = 0; } if (interim_response) { /* RFC2616 tells us to forward this. * * OTOH, an interim response here may mean the backend * is playing sillybuggers. The Client didn't ask for * it within the defined HTTP/1.1 mechanisms, and if * it's an extension, it may also be unsupported by us. * * There's also the possibility that changing existing * behaviour here might break something. * * So let's make it configurable. */ const char *policy = apr_table_get(r->subprocess_env, "proxy-interim-response"); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL, "proxy: HTTP: received interim %d response", r->status); if (!policy || !strcasecmp(policy, "RFC")) { ap_send_interim_response(r, 1); } /* FIXME: refine this to be able to specify per-response-status * policies and maybe also add option to bail out with 502 */ else if (strcasecmp(policy, "Suppress")) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, NULL, "undefined proxy interim response policy"); } } /* Moved the fixups of Date headers and those affected by * ProxyPassReverse/etc from here to ap_proxy_read_headers */ if ((r->status == 401) && (conf->error_override)) { const char *buf; const char *wa = "WWW-Authenticate"; if ((buf = apr_table_get(r->headers_out, wa))) { apr_table_set(r->err_headers_out, wa, buf); } else { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: origin server sent 401 without WWW-Authenticate header"); } } r->sent_bodyct = 1; /* * Is it an HTTP/0.9 response or did we maybe preread the 1st line of * the response? If so, load the extra data. These are 2 mutually * exclusive possibilities, that just happen to require very * similar behavior. */ if (backasswards || pread_len) { apr_ssize_t cntr = (apr_ssize_t)pread_len; if (backasswards) { /*@@@FIXME: * At this point in response processing of a 0.9 response, * we don't know yet whether data is binary or not. * mod_charset_lite will get control later on, so it cannot * decide on the conversion of this buffer full of data. * However, chances are that we are not really talking to an * HTTP/0.9 server, but to some different protocol, therefore * the best guess IMHO is to always treat the buffer as "text/x": */ ap_xlate_proto_to_ascii(buffer, len); cntr = (apr_ssize_t)len; } e = apr_bucket_heap_create(buffer, cntr, NULL, c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); } /* send body - but only if a body is expected */ if ((!r->header_only) && /* not HEAD request */ !interim_response && /* not any 1xx response */ (r->status != HTTP_NO_CONTENT) && /* not 204 */ (r->status != HTTP_NOT_MODIFIED)) { /* not 304 */ /* We need to copy the output headers and treat them as input * headers as well. BUT, we need to do this before we remove * TE, so that they are preserved accordingly for * ap_http_filter to know where to end. */ rp->headers_in = apr_table_copy(r->pool, r->headers_out); /* * Restore Transfer-Encoding header from response if we saved * one before and there is none left. We need it for the * ap_http_filter. See above. */ if (te && !apr_table_get(rp->headers_in, "Transfer-Encoding")) { apr_table_add(rp->headers_in, "Transfer-Encoding", te); } apr_table_unset(r->headers_out,"Transfer-Encoding"); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: start body send"); /* * if we are overriding the errors, we can't put the content * of the page into the brigade */ if (!conf->error_override || !ap_is_HTTP_ERROR(r->status)) { /* read the body, pass it to the output filters */ apr_read_type_e mode = APR_NONBLOCK_READ; int finish = FALSE; do { apr_off_t readbytes; apr_status_t rv; rv = ap_get_brigade(rp->input_filters, bb, AP_MODE_READBYTES, mode, conf->io_buffer_size); /* ap_get_brigade will return success with an empty brigade * for a non-blocking read which would block: */ if (APR_STATUS_IS_EAGAIN(rv) || (rv == APR_SUCCESS && APR_BRIGADE_EMPTY(bb))) { /* flush to the client and switch to blocking mode */ e = apr_bucket_flush_create(c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); if (ap_pass_brigade(r->output_filters, bb) || c->aborted) { backend->close = 1; break; } apr_brigade_cleanup(bb); mode = APR_BLOCK_READ; continue; } else if (rv == APR_EOF) { break; } else if (rv != APR_SUCCESS) { /* In this case, we are in real trouble because * our backend bailed on us. Pass along a 502 error * error bucket */ ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c, "proxy: error reading response"); ap_proxy_backend_broke(r, bb); ap_pass_brigade(r->output_filters, bb); backend_broke = 1; backend->close = 1; break; } /* next time try a non-blocking read */ mode = APR_NONBLOCK_READ; apr_brigade_length(bb, 0, &readbytes); backend->worker->s->read += readbytes; #if DEBUGGING { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy (PID %d): readbytes: %#x", getpid(), readbytes); } #endif /* sanity check */ if (APR_BRIGADE_EMPTY(bb)) { apr_brigade_cleanup(bb); break; } /* found the last brigade? */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(bb))) { /* signal that we must leave */ finish = TRUE; } /* try send what we read */ if (ap_pass_brigade(r->output_filters, bb) != APR_SUCCESS || c->aborted) { /* Ack! Phbtt! Die! User aborted! */ backend->close = 1; /* this causes socket close below */ finish = TRUE; } /* make sure we always clean up after ourselves */ apr_brigade_cleanup(bb); } while (!finish); } ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: end body send"); } else if (!interim_response) { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: header only"); /* Pass EOS bucket down the filter chain. */ e = apr_bucket_eos_create(c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); if (ap_pass_brigade(r->output_filters, bb) != APR_SUCCESS || c->aborted) { /* Ack! Phbtt! Die! User aborted! */ backend->close = 1; /* this causes socket close below */ } apr_brigade_cleanup(bb); } } while (interim_response && (interim_response < AP_MAX_INTERIM_RESPONSES)); /* See define of AP_MAX_INTERIM_RESPONSES for why */ if (interim_response >= AP_MAX_INTERIM_RESPONSES) { return ap_proxyerror(r, HTTP_BAD_GATEWAY, apr_psprintf(p, "Too many (%d) interim responses from origin server", interim_response)); } /* If our connection with the client is to be aborted, return DONE. */ if (c->aborted || backend_broke) { return DONE; } if (conf->error_override) { /* the code above this checks for 'OK' which is what the hook expects */ if (!ap_is_HTTP_ERROR(r->status)) return OK; else { /* clear r->status for override error, otherwise ErrorDocument * thinks that this is a recursive error, and doesn't find the * custom error page */ int status = r->status; r->status = HTTP_OK; /* Discard body, if one is expected */ if (!r->header_only && /* not HEAD request */ (status != HTTP_NO_CONTENT) && /* not 204 */ (status != HTTP_NOT_MODIFIED)) { /* not 304 */ ap_discard_request_body(rp); } return status; } } else return OK; } static apr_status_t ap_proxy_http_cleanup(const char *scheme, request_rec *r, proxy_conn_rec *backend) { ap_proxy_release_connection(scheme, backend, r->server); return OK; } /* * This handles http:// URLs, and other URLs using a remote proxy over http * If proxyhost is NULL, then contact the server directly, otherwise * go via the proxy. * Note that if a proxy is used, then URLs other than http: can be accessed, * also, if we have trouble which is clearly specific to the proxy, then * we return DECLINED so that we can try another proxy. (Or the direct * route.) */ static int proxy_http_handler(request_rec *r, proxy_worker *worker, proxy_server_conf *conf, char *url, const char *proxyname, apr_port_t proxyport) { int status; char server_portstr[32]; char *scheme; const char *proxy_function; const char *u; proxy_conn_rec *backend = NULL; int is_ssl = 0; /* Note: Memory pool allocation. * A downstream keepalive connection is always connected to the existence * (or not) of an upstream keepalive connection. If this is not done then * load balancing against multiple backend servers breaks (one backend * server ends up taking 100% of the load), and the risk is run of * downstream keepalive connections being kept open unnecessarily. This * keeps webservers busy and ties up resources. * * As a result, we allocate all sockets out of the upstream connection * pool, and when we want to reuse a socket, we check first whether the * connection ID of the current upstream connection is the same as that * of the connection when the socket was opened. */ apr_pool_t *p = r->connection->pool; conn_rec *c = r->connection; apr_uri_t *uri = apr_palloc(r->connection->pool, sizeof(*uri)); /* find the scheme */ u = strchr(url, ':'); if (u == NULL || u[1] != '/' || u[2] != '/' || u[3] == '\0') return DECLINED; if ((u - url) > 14) return HTTP_BAD_REQUEST; scheme = apr_pstrndup(c->pool, url, u - url); /* scheme is lowercase */ ap_str_tolower(scheme); /* is it for us? */ if (strcmp(scheme, "https") == 0) { if (!ap_proxy_ssl_enable(NULL)) { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: HTTPS: declining URL %s" " (mod_ssl not configured?)", url); return DECLINED; } is_ssl = 1; proxy_function = "HTTPS"; } else if (!(strcmp(scheme, "http") == 0 || (strcmp(scheme, "ftp") == 0 && proxyname))) { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: HTTP: declining URL %s", url); return DECLINED; /* only interested in HTTP, or FTP via proxy */ } else { if (*scheme == 'h') proxy_function = "HTTP"; else proxy_function = "FTP"; } ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "proxy: HTTP: serving URL %s", url); /* create space for state information */ if ((status = ap_proxy_acquire_connection(proxy_function, &backend, worker, r->server)) != OK) goto cleanup; backend->is_ssl = is_ssl; if (is_ssl) { ap_proxy_ssl_connection_cleanup(backend, r); } /* * In the case that we are handling a reverse proxy connection and this * is not a request that is coming over an already kept alive connection * with the client, do NOT reuse the connection to the backend, because * we cannot forward a failure to the client in this case as the client * does NOT expects this in this situation. * Yes, this creates a performance penalty. */ if ((r->proxyreq == PROXYREQ_REVERSE) && (!c->keepalives) && (apr_table_get(r->subprocess_env, "proxy-initial-not-pooled"))) { backend->close = 1; } /* Step One: Determine Who To Connect To */ if ((status = ap_proxy_determine_connection(p, r, conf, worker, backend, uri, &url, proxyname, proxyport, server_portstr, sizeof(server_portstr))) != OK) goto cleanup; /* Step Two: Make the Connection */ if (ap_proxy_connect_backend(proxy_function, backend, worker, r->server)) { if (r->proxyreq == PROXYREQ_PROXY) status = HTTP_NOT_FOUND; else status = HTTP_SERVICE_UNAVAILABLE; goto cleanup; } /* Step Three: Create conn_rec */ if (!backend->connection) { if ((status = ap_proxy_connection_create(proxy_function, backend, c, r->server)) != OK) goto cleanup; } /* Step Four: Send the Request */ if ((status = ap_proxy_http_request(p, r, backend, backend->connection, conf, uri, url, server_portstr)) != OK) goto cleanup; /* Step Five: Receive the Response */ if ((status = ap_proxy_http_process_response(p, r, backend, backend->connection, conf, server_portstr)) != OK) goto cleanup; /* Step Six: Clean Up */ cleanup: if (backend) { if (status != OK) backend->close = 1; ap_proxy_http_cleanup(proxy_function, r, backend); } return status; } static apr_status_t warn_rx_free(void *p) { ap_pregfree((apr_pool_t*)p, warn_rx); return APR_SUCCESS; } static void ap_proxy_http_register_hook(apr_pool_t *p) { proxy_hook_scheme_handler(proxy_http_handler, NULL, NULL, APR_HOOK_FIRST); proxy_hook_canon_handler(proxy_http_canon, NULL, NULL, APR_HOOK_FIRST); warn_rx = ap_pregcomp(p, "[0-9]{3}[ \t]+[^ \t]+[ \t]+\"[^\"]*\"([ \t]+\"([^\"]+)\")?", 0); apr_pool_cleanup_register(p, p, warn_rx_free, apr_pool_cleanup_null); } module AP_MODULE_DECLARE_DATA proxy_http_module = { STANDARD20_MODULE_STUFF, NULL, /* create per-directory config structure */ NULL, /* merge per-directory config structures */ NULL, /* create per-server config structure */ NULL, /* merge per-server config structures */ NULL, /* command apr_table_t */ ap_proxy_http_register_hook/* register hooks */ };
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