/* 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 int (*ap_proxy_clear_connection_fn)(request_rec *r, apr_table_t *headers) = NULL; static apr_status_t ap_proxy_http_cleanup(const char *scheme, request_rec *r, proxy_conn_rec *backend); static apr_status_t ap_proxygetline(apr_bucket_brigade *bb, char *s, int n, request_rec *r, int flags, int *read); static const char *get_url_scheme(const char **url, int *is_ssl) { const char *u = *url; switch (u[0]) { case 'h': case 'H': if (strncasecmp(u + 1, "ttp", 3) == 0) { if (u[4] == ':') { *is_ssl = 0; *url = u + 5; return "http"; } if (apr_tolower(u[4]) == 's' && u[5] == ':') { *is_ssl = 1; *url = u + 6; return "https"; } } break; case 'w': case 'W': if (apr_tolower(u[1]) == 's') { if (u[2] == ':') { *is_ssl = 0; *url = u + 3; return "ws"; } if (apr_tolower(u[2]) == 's' && u[3] == ':') { *is_ssl = 1; *url = u + 4; return "wss"; } } break; } *is_ssl = 0; return NULL; } /* * Canonicalise http-like URLs. * scheme is the scheme for the URL * url is the URL starting with the first '/' */ static int proxy_http_canon(request_rec *r, char *url) { const char *base_url = url; char *host, *path, sport[7]; char *search = NULL; const char *err; const char *scheme; apr_port_t port, def_port; int is_ssl = 0; scheme = get_url_scheme((const char **)&url, &is_ssl); if (!scheme) { return DECLINED; } port = def_port = (is_ssl) ? DEFAULT_HTTPS_PORT : DEFAULT_HTTP_PORT; ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "HTTP: canonicalising URL %s", base_url); /* do syntatic check. * We break the URL into host, port, path, search */ err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port); if (err) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01083) "error parsing URL %s: %s", base_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 if (apr_table_get(r->notes, "proxy-noencode")) { path = url; /* this is the encoded path already */ search = r->args; } else { core_dir_config *d = ap_get_core_module_config(r->per_dir_config); int flags = d->allow_encoded_slashes && !d->decode_encoded_slashes ? PROXY_CANONENC_NOENCODEDSLASHENCODING : 0; path = ap_proxy_canonenc_ex(r->pool, url, strlen(url), enc_path, flags, r->proxyreq); if (!path) { return HTTP_BAD_REQUEST; } search = r->args; } break; case PROXYREQ_PROXY: path = url; break; } /* * If we have a raw control character or a ' ' in nocanon path or * r->args, correct encoding was missed. */ if (path == url && *ap_scan_vchar_obstext(path)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10415) "To be forwarded path contains control " "characters or spaces"); return HTTP_FORBIDDEN; } if (search && *ap_scan_vchar_obstext(search)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10408) "To be forwarded query string contains control " "characters or spaces"); return HTTP_FORBIDDEN; } 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, 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 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); } #ifndef CRLF_ASCII #define CRLF_ASCII "\015\012" #endif #ifndef ZERO_ASCII #define ZERO_ASCII "\060" #endif #define MAX_MEM_SPOOL 16384 typedef enum { RB_INIT = 0, RB_STREAM_CL, RB_STREAM_CHUNKED, RB_SPOOL_CL } rb_methods; typedef struct { apr_pool_t *p; request_rec *r; const char *proto; proxy_worker *worker; proxy_server_conf *sconf; char server_portstr[32]; proxy_conn_rec *backend; conn_rec *origin; apr_bucket_alloc_t *bucket_alloc; apr_bucket_brigade *header_brigade; apr_bucket_brigade *input_brigade; char *old_cl_val, *old_te_val; apr_off_t cl_val; rb_methods rb_method; const char *upgrade; unsigned int do_100_continue :1, prefetch_nonblocking :1, force10 :1; } proxy_http_req_t; static int stream_reqbody(proxy_http_req_t *req) { request_rec *r = req->r; int seen_eos = 0, rv = OK; apr_size_t hdr_len; char chunk_hdr[20]; /* must be here due to transient bucket. */ conn_rec *origin = req->origin; proxy_conn_rec *p_conn = req->backend; apr_bucket_alloc_t *bucket_alloc = req->bucket_alloc; apr_bucket_brigade *header_brigade = req->header_brigade; apr_bucket_brigade *input_brigade = req->input_brigade; rb_methods rb_method = req->rb_method; apr_off_t bytes, bytes_streamed = 0; apr_bucket *e; do { if (APR_BRIGADE_EMPTY(input_brigade) && APR_BRIGADE_EMPTY(header_brigade)) { rv = ap_proxy_read_input(r, p_conn, input_brigade, HUGE_STRING_LEN); if (rv != OK) { return rv; } } if (!APR_BRIGADE_EMPTY(input_brigade)) { /* If this brigade contains EOS, remove it and be done. */ 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); bytes_streamed += bytes; if (rb_method == RB_STREAM_CHUNKED) { if (bytes) { /* * Prepend the size of the chunk */ 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(CRLF_ASCII, 2, bucket_alloc); APR_BRIGADE_INSERT_TAIL(input_brigade, e); } if (seen_eos) { /* * Append the tailing 0-size chunk */ e = apr_bucket_immortal_create(ZERO_ASCII CRLF_ASCII /* */ CRLF_ASCII, 5, bucket_alloc); APR_BRIGADE_INSERT_TAIL(input_brigade, e); } } else if (rb_method == RB_STREAM_CL && (bytes_streamed > req->cl_val || (seen_eos && bytes_streamed < req->cl_val))) { /* C-L != bytes streamed?!? * * Prevent HTTP Request/Response Splitting. * * We can't stream more (or less) bytes at the back end since * they could be interpreted in separate requests (more bytes * now would start a new request, less bytes would make the * first bytes of the next request be part of the current one). * * It can't happen from the client connection here thanks to * ap_http_filter(), but some module's filter may be playing * bad games, hence the HTTP_INTERNAL_SERVER_ERROR. */ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01086) "read %s bytes of request body than expected " "(got %" APR_OFF_T_FMT ", expected " "%" APR_OFF_T_FMT ")", bytes_streamed > req->cl_val ? "more" : "less", bytes_streamed, req->cl_val); return HTTP_INTERNAL_SERVER_ERROR; } if (seen_eos && apr_table_get(r->subprocess_env, "proxy-sendextracrlf")) { e = apr_bucket_immortal_create(CRLF_ASCII, 2, bucket_alloc); APR_BRIGADE_INSERT_TAIL(input_brigade, e); } } /* If we never sent the header brigade, go ahead and take care of * that now by prepending it (once only since header_brigade will be * empty afterward). */ APR_BRIGADE_PREPEND(input_brigade, header_brigade); /* Flush here on EOS because we won't ap_proxy_read_input() again. */ rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, input_brigade, seen_eos); if (rv != OK) { return rv; } } while (!seen_eos); return OK; } static void terminate_headers(proxy_http_req_t *req) { apr_bucket_alloc_t *bucket_alloc = req->bucket_alloc; apr_bucket *e; char *buf; /* * 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 (!req->force10) { if (req->upgrade) { buf = apr_pstrdup(req->p, "Connection: Upgrade" CRLF); ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), req->p, bucket_alloc); APR_BRIGADE_INSERT_TAIL(req->header_brigade, e); /* Tell the backend that it can upgrade the connection. */ buf = apr_pstrcat(req->p, "Upgrade: ", req->upgrade, CRLF, NULL); } else if (ap_proxy_connection_reusable(req->backend)) { buf = apr_pstrdup(req->p, "Connection: Keep-Alive" CRLF); } else { buf = apr_pstrdup(req->p, "Connection: close" CRLF); } ap_xlate_proto_to_ascii(buf, strlen(buf)); e = apr_bucket_pool_create(buf, strlen(buf), req->p, bucket_alloc); APR_BRIGADE_INSERT_TAIL(req->header_brigade, e); } /* add empty line at the end of the headers */ e = apr_bucket_immortal_create(CRLF_ASCII, 2, bucket_alloc); APR_BRIGADE_INSERT_TAIL(req->header_brigade, e); } static int ap_proxy_http_prefetch(proxy_http_req_t *req, apr_uri_t *uri, char *url) { apr_pool_t *p = req->p; request_rec *r = req->r; conn_rec *c = r->connection; proxy_conn_rec *p_conn = req->backend; apr_bucket_alloc_t *bucket_alloc = req->bucket_alloc; apr_bucket_brigade *header_brigade = req->header_brigade; apr_bucket_brigade *input_brigade = req->input_brigade; apr_bucket *e; apr_off_t bytes_read = 0; apr_off_t bytes; int rv; rv = ap_proxy_create_hdrbrgd(p, header_brigade, r, p_conn, req->worker, req->sconf, uri, url, req->server_portstr, &req->old_cl_val, &req->old_te_val); if (rv != OK) { return rv; } /* 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 unpleasant. * * An exception: when a kept_body is present, then subrequest CAN use * pass request bodies, and we DONT skip the body. */ if (!r->kept_body && r->main) { /* XXX: Why DON'T sub-requests use keepalives? */ p_conn->close = 1; req->old_te_val = NULL; req->old_cl_val = NULL; req->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 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 (req->old_te_val && ap_cstr_casecmp(req->old_te_val, "chunked") != 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01093) "%s Transfer-Encoding is not supported", req->old_te_val); return HTTP_INTERNAL_SERVER_ERROR; } if (req->old_cl_val && req->old_te_val) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01094) "client %s (%s) requested Transfer-Encoding " "chunked body with Content-Length (C-L ignored)", c->client_ip, c->remote_host ? c->remote_host: ""); req->old_cl_val = NULL; p_conn->close = 1; } rv = ap_proxy_prefetch_input(r, req->backend, input_brigade, req->prefetch_nonblocking ? APR_NONBLOCK_READ : APR_BLOCK_READ, &bytes_read, MAX_MEM_SPOOL); if (rv != OK) { return rv; } /* 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 desirable. * * 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_BRIGADE_EMPTY(input_brigade) && 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 (req->old_cl_val || req->old_te_val || bytes_read) { req->old_cl_val = apr_off_t_toa(r->pool, bytes_read); req->cl_val = bytes_read; } req->rb_method = RB_STREAM_CL; } else if (req->old_te_val) { if (req->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"))) { req->rb_method = RB_SPOOL_CL; } else { req->rb_method = RB_STREAM_CHUNKED; } } else if (req->old_cl_val) { if (r->input_filters == r->proto_input_filters) { if (!ap_parse_strict_length(&req->cl_val, req->old_cl_val)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01085) "could not parse request Content-Length (%s)", req->old_cl_val); return HTTP_BAD_REQUEST; } req->rb_method = RB_STREAM_CL; } else if (!req->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")) { req->rb_method = RB_STREAM_CHUNKED; } else { req->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. */ req->rb_method = RB_SPOOL_CL; } switch (req->rb_method) { case RB_STREAM_CHUNKED: add_te_chunked(req->p, bucket_alloc, header_brigade); break; case RB_STREAM_CL: if (req->old_cl_val) { add_cl(req->p, bucket_alloc, header_brigade, req->old_cl_val); } break; default: /* => RB_SPOOL_CL */ /* If we have to spool the body, do it now, before connecting or * reusing the backend connection. */ rv = ap_proxy_spool_input(r, p_conn, input_brigade, &bytes, MAX_MEM_SPOOL); if (rv != OK) { return rv; } if (bytes || req->old_te_val || req->old_cl_val) { add_cl(p, bucket_alloc, header_brigade, apr_off_t_toa(p, bytes)); } } /* Yes I hate gotos. This is the subrequest shortcut */ skip_body: terminate_headers(req); return OK; } static int ap_proxy_http_request(proxy_http_req_t *req) { int rv; request_rec *r = req->r; /* send the request header/body, if any. */ switch (req->rb_method) { case RB_SPOOL_CL: case RB_STREAM_CL: case RB_STREAM_CHUNKED: if (req->do_100_continue) { rv = ap_proxy_pass_brigade(req->bucket_alloc, r, req->backend, req->origin, req->header_brigade, 1); } else { rv = stream_reqbody(req); } break; default: /* shouldn't be possible */ rv = HTTP_INTERNAL_SERVER_ERROR; break; } if (rv != OK) { conn_rec *c = r->connection; /* apr_status_t value has been logged in lower level method */ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01097) "pass request body failed to %pI (%s) from %s (%s)", req->backend->addr, req->backend->hostname ? req->backend->hostname: "", c->client_ip, c->remote_host ? c->remote_host: ""); return rv; } return OK; } /* * If the date is a valid RFC 850 date or asctime() date, then it * is converted to the RFC 1123 format. */ static const char *date_canon(apr_pool_t *p, const char *date) { apr_status_t rv; char* ndate; apr_time_t time = apr_date_parse_http(date); if (!time) { return date; } ndate = apr_palloc(p, APR_RFC822_DATE_LEN); rv = apr_rfc822_date(ndate, time); if (rv != APR_SUCCESS) { return date; } return ndate; } static request_rec *make_fake_req(conn_rec *c, request_rec *r) { apr_pool_t *pool; request_rec *rp; apr_pool_create(&pool, c->pool); apr_pool_tag(pool, "proxy_http_rp"); rp = apr_pcalloc(pool, sizeof(*r)); rp->pool = pool; rp->status = HTTP_OK; rp->headers_in = apr_table_make(pool, 50); rp->trailers_in = apr_table_make(pool, 5); rp->subprocess_env = apr_table_make(pool, 50); rp->headers_out = apr_table_make(pool, 12); rp->trailers_out = apr_table_make(pool, 5); rp->err_headers_out = apr_table_make(pool, 5); rp->notes = apr_table_make(pool, 5); rp->server = r->server; rp->log = r->log; rp->proxyreq = r->proxyreq; rp->request_time = r->request_time; rp->connection = c; rp->output_filters = c->output_filters; rp->input_filters = c->input_filters; rp->proto_output_filters = c->output_filters; rp->proto_input_filters = c->input_filters; rp->useragent_ip = c->client_ip; rp->useragent_addr = c->client_addr; rp->request_config = ap_create_request_config(pool); proxy_run_create_req(r, rp); return rp; } 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 (!ap_cstr_casecmp(date_hdrs[i], key)) { apr_table_add(r->headers_out, key, date_canon(r->pool, value)); return; } } for (i = 0; transform_hdrs[i].name; ++i) { if (!ap_cstr_casecmp(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); } /* * 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 apr_status_t 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; int saw_headers = 0; void *sconf = r->server->module_config; proxy_server_conf *psc; proxy_dir_conf *dconf; apr_status_t rc; apr_bucket_brigade *tmp_bb; 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); r->trailers_out = apr_table_make(r->pool, 5); *pread_len = 0; /* * Read header lines until we get the empty separator line, a read error, * the connection closes (EOF), or we timeout. */ ap_log_rerror(APLOG_MARK, APLOG_TRACE4, 0, r, "Headers received from backend:"); tmp_bb = apr_brigade_create(r->pool, c->bucket_alloc); while (1) { rc = ap_proxygetline(tmp_bb, buffer, size, rr, AP_GETLINE_FOLD | AP_GETLINE_NOSPC_EOL, &len); if (rc != APR_SUCCESS) { if (APR_STATUS_IS_ENOSPC(rc)) { int trunc = (len > 128 ? 128 : len) / 2; ap_log_rerror(APLOG_MARK, APLOG_WARNING, rc, r, APLOGNO(10124) "header size is over the limit allowed by " "ResponseFieldSize (%d bytes). " "Bad response header: '%.*s[...]%s'", size, trunc, buffer, buffer + len - trunc); } else { ap_log_rerror(APLOG_MARK, APLOG_WARNING, rc, r, APLOGNO(10404) "Error reading headers from backend"); } r->headers_out = NULL; return rc; } if (len <= 0) { break; } else { ap_log_rerror(APLOG_MARK, APLOG_TRACE4, 0, r, "%s", buffer); } 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 APR_EINVAL; } 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_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01098) "Starting body due to bogus non-header " "in headers returned by %s (%s)", r->uri, r->method); *pread_len = len; return APR_SUCCESS; } else { ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01099) "No HTTP headers returned by %s (%s)", r->uri, r->method); return APR_SUCCESS; } } } /* this is the psc->badopt == bad_ignore case */ ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01100) "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; } return APR_SUCCESS; } 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 flags, int *read) { apr_status_t rv; apr_size_t len; rv = ap_rgetline(&s, n, &len, r, flags, bb); apr_brigade_cleanup(bb); if (rv == APR_SUCCESS || APR_STATUS_IS_ENOSPC(rv)) { *read = (int)len; } else { *read = -1; } return rv; } /* * Limit the number of interim responses 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 int add_trailers(void *data, const char *key, const char *val) { if (val) { apr_table_add((apr_table_t*)data, key, val); } return 1; } static int send_continue_body(proxy_http_req_t *req) { int status; /* Send the request body (fully). */ switch(req->rb_method) { case RB_SPOOL_CL: case RB_STREAM_CL: case RB_STREAM_CHUNKED: status = stream_reqbody(req); break; default: /* Shouldn't happen */ status = HTTP_INTERNAL_SERVER_ERROR; break; } if (status != OK) { conn_rec *c = req->r->connection; ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req->r, APLOGNO(10154) "pass request body failed " "to %pI (%s) from %s (%s) with status %i", req->backend->addr, req->backend->hostname ? req->backend->hostname : "", c->client_ip, c->remote_host ? c->remote_host : "", status); req->backend->close = 1; } return status; } static int ap_proxy_http_process_response(proxy_http_req_t *req) { apr_pool_t *p = req->p; request_rec *r = req->r; conn_rec *c = r->connection; proxy_worker *worker = req->worker; proxy_conn_rec *backend = req->backend; conn_rec *origin = req->origin; int do_100_continue = req->do_100_continue; int status; char *buffer; char fixed_buffer[HUGE_STRING_LEN]; const char *buf; char keepchar; apr_bucket *e; apr_bucket_brigade *bb; apr_bucket_brigade *pass_bb; int len, backasswards; int interim_response = 0; /* non-zero whilst interim 1xx responses * are being read. */ apr_size_t response_field_size = 0; 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; int original_status = r->status; int proxy_status = OK; const char *original_status_line = r->status_line; const char *proxy_status_line = NULL; apr_interval_time_t old_timeout = 0; proxy_dir_conf *dconf; dconf = ap_get_module_config(r->per_dir_config, &proxy_module); bb = apr_brigade_create(p, c->bucket_alloc); pass_bb = apr_brigade_create(p, c->bucket_alloc); /* Only use dynamically sized buffer if user specifies ResponseFieldSize */ if(backend->worker->s->response_field_size_set) { response_field_size = backend->worker->s->response_field_size; if (response_field_size != HUGE_STRING_LEN) buffer = apr_pcalloc(p, response_field_size); else buffer = fixed_buffer; } else { response_field_size = HUGE_STRING_LEN; buffer = fixed_buffer; } /* Setup for 100-Continue timeout if appropriate */ if (do_100_continue && worker->s->ping_timeout_set) { apr_socket_timeout_get(backend->sock, &old_timeout); if (worker->s->ping_timeout != old_timeout) { apr_status_t rc; rc = apr_socket_timeout_set(backend->sock, worker->s->ping_timeout); if (rc != APR_SUCCESS) { ap_log_rerror(APLOG_MARK, APLOG_ERR, rc, r, APLOGNO(01101) "could not set 100-Continue timeout"); } } } /* Get response from the remote server, and pass it up the * filter chain */ backend->r = make_fake_req(origin, r); /* In case anyone needs to know, this is a fake request that is really a * response. */ backend->r->proxyreq = PROXYREQ_RESPONSE; apr_table_setn(r->notes, "proxy-source-port", apr_psprintf(r->pool, "%hu", origin->local_addr->port)); do { apr_status_t rc; const char *upgrade = NULL; int major = 0, minor = 0; int toclose = 0; apr_brigade_cleanup(bb); rc = ap_proxygetline(backend->tmp_bb, buffer, response_field_size, backend->r, 0, &len); if (len == 0) { /* handle one potential stray CRLF */ rc = ap_proxygetline(backend->tmp_bb, buffer, response_field_size, backend->r, 0, &len); } if (len <= 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, rc, r, APLOGNO(01102) "error reading status line from remote " "server %s:%d", backend->hostname, backend->port); if (APR_STATUS_IS_TIMEUP(rc)) { apr_table_setn(r->notes, "proxy_timedout", "1"); ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01103) "read timeout"); if (do_100_continue) { return ap_proxyerror(r, HTTP_SERVICE_UNAVAILABLE, "Timeout on 100-Continue"); } } /* * 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 && !APR_STATUS_IS_TIMEUP(rc)) { apr_bucket *eos; ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01104) "Closing connection to client because" " reading from backend server %s:%d failed." " Number of keepalives %i", backend->hostname, backend->port, 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); /* Mark the backend connection for closing */ backend->close = 1; if (origin->keepalives) { /* We already had a request on this backend connection and * might just have run into a keepalive race. Hence we * think positive and assume that the backend is fine and * we do not need to signal an error on backend side. */ return OK; } /* * This happened on our first request on this connection to the * backend. This indicates something fishy with the backend. * Return HTTP_INTERNAL_SERVER_ERROR to signal an unrecoverable * server error. We do not worry about r->status code and a * possible error response here as the ap_http_outerror_filter * will fix all of this for us. */ return HTTP_INTERNAL_SERVER_ERROR; } if (!c->keepalives) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01105) "NOT Closing connection to client" " although reading from backend server %s:%d" " failed.", backend->hostname, backend->port); } 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/#.# ###*")) { major = buffer[5] - '0'; minor = buffer[7] - '0'; /* If not an HTTP/1 message or * if the status line was > 8192 bytes */ if ((major != 1) || (len >= response_field_size - 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'; proxy_status = atoi(&buffer[9]); apr_table_setn(r->notes, "proxy-status", apr_pstrdup(r->pool, &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'; } proxy_status_line = apr_pstrdup(p, &buffer[9]); /* The status out of the front is the same as the status coming in * from the back, until further notice. */ r->status = proxy_status; r->status_line = proxy_status_line; ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, "Status from backend: %d", proxy_status); /* read the headers. */ /* N.B. for HTTP/1.0 clients, we have to fold line-wrapped headers*/ /* Also, take care with headers with multiple occurrences. */ /* 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 */ rc = ap_proxy_read_headers(r, backend->r, buffer, response_field_size, origin, &pread_len); if (rc != APR_SUCCESS || r->headers_out == NULL) { ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01106) "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); } /* * 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"); /* can't have both Content-Length and Transfer-Encoding */ if (te && 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_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01107) "server %s:%d returned Transfer-Encoding" " and Content-Length", backend->hostname, backend->port); backend->close = 1; } upgrade = apr_table_get(r->headers_out, "Upgrade"); if (proxy_status == HTTP_SWITCHING_PROTOCOLS) { if (!upgrade || !req->upgrade || (strcasecmp(req->upgrade, upgrade) != 0)) { return ap_proxyerror(r, HTTP_BAD_GATEWAY, apr_pstrcat(p, "Unexpected Upgrade: ", upgrade ? upgrade : "n/a", " (expecting ", req->upgrade ? req->upgrade : "n/a", ")", NULL)); } backend->close = 1; } /* strip connection listed hop-by-hop headers from response */ toclose = ap_proxy_clear_connection_fn(r, r->headers_out); if (toclose) { backend->close = 1; if (toclose < 0) { return ap_proxyerror(r, HTTP_BAD_GATEWAY, "Malformed connection header"); } } if ((buf = apr_table_get(r->headers_out, "Content-Type"))) { ap_set_content_type(r, apr_pstrdup(p, buf)); } if (!ap_is_HTTP_INFO(proxy_status)) { ap_proxy_pre_http_request(origin, backend->r); } /* 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 (req->sconf->viaopt != via_off && req->sconf->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", (req->sconf->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, req->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, req->server_portstr) ); } /* cancel keepalive if HTTP/1.0 or less */ if ((major < 1) || (minor < 1)) { backend->close = 1; origin->keepalive = AP_CONN_CLOSE; } else { /* * Keep track of the number of keepalives we processed on this * connection. */ origin->keepalives++; } } else { /* an http/0.9 response */ backasswards = 1; r->status = proxy_status = 200; r->status_line = "200 OK"; backend->close = 1; } if (ap_is_HTTP_INFO(proxy_status)) { const char *policy = NULL; /* 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. * * We need to force "r->expecting_100 = 1" for RFC behaviour * otherwise ap_send_interim_response() does nothing when * the client did not ask for 100-continue. * * 101 Switching Protocol has its own configuration which * shouldn't be interfered by "proxy-interim-response". */ if (proxy_status != HTTP_SWITCHING_PROTOCOLS) { policy = apr_table_get(r->subprocess_env, "proxy-interim-response"); } ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "HTTP: received interim %d response (policy: %s)", r->status, policy ? policy : "n/a"); if (!policy || (!strcasecmp(policy, "RFC") && (proxy_status != HTTP_CONTINUE || (r->expecting_100 = 1)))) { switch (proxy_status) { case HTTP_SWITCHING_PROTOCOLS: AP_DEBUG_ASSERT(upgrade != NULL); apr_table_setn(r->headers_out, "Connection", "Upgrade"); apr_table_setn(r->headers_out, "Upgrade", apr_pstrdup(p, upgrade)); break; } 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_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01108) "undefined proxy interim response policy"); } interim_response++; } else { interim_response = 0; } /* If we still do 100-continue (end-to-end or ping), either the * current response is the expected "100 Continue" and we are done * with this mode, or this is another interim response and we'll wait * for the next one, or this is a final response and hence the backend * did not honor our expectation. */ if (do_100_continue && (!interim_response || proxy_status == HTTP_CONTINUE)) { /* RFC 7231 - Section 5.1.1 - Expect - Requirement for servers * A server that responds with a final status code before * reading the entire message body SHOULD indicate in that * response whether it intends to close the connection or * continue reading and discarding the request message. * * So, if this response is not an interim 100 Continue, we can * avoid sending the request body if the backend responded with * "Connection: close" or HTTP < 1.1, and either let the core * discard it or the caller try another balancer member with the * same body (given status 503, though not implemented yet). */ int do_send_body = (proxy_status == HTTP_CONTINUE || (!toclose && major > 0 && minor > 0)); /* Reset to old timeout iff we've adjusted it. */ if (worker->s->ping_timeout_set) { apr_socket_timeout_set(backend->sock, old_timeout); } ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(10153) "HTTP: %s100 continue sent by %pI (%s): " "%ssending body (response: HTTP/%i.%i %s)", proxy_status != HTTP_CONTINUE ? "no " : "", backend->addr, backend->hostname ? backend->hostname : "", do_send_body ? "" : "not ", major, minor, proxy_status_line); if (do_send_body) { status = send_continue_body(req); if (status != OK) { return status; } } else { /* If we don't read the client connection any further, since * there are pending data it should be "Connection: close"d to * prevent reuse. We don't exactly c->keepalive = AP_CONN_CLOSE * here though, because error_override or a potential retry on * another backend could finally read that data and finalize * the request processing, making keep-alive possible. So what * we do is leaving r->expecting_100 alone, ap_set_keepalive() * will do the right thing according to the final response and * any later update of r->expecting_100. */ } /* Once only! */ do_100_continue = 0; } if (proxy_status == HTTP_SWITCHING_PROTOCOLS) { apr_status_t rv; proxy_tunnel_rec *tunnel; apr_interval_time_t client_timeout = -1, backend_timeout = -1; /* If we didn't send the full body yet, do it now */ if (do_100_continue) { r->expecting_100 = 0; status = send_continue_body(req); if (status != OK) { return status; } } ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(10239) "HTTP: tunneling protocol %s", upgrade); rv = ap_proxy_tunnel_create(&tunnel, r, origin, upgrade); if (rv != APR_SUCCESS) { ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(10240) "can't create tunnel for %s", upgrade); return HTTP_INTERNAL_SERVER_ERROR; } /* Set timeout to the highest configured for client or backend */ apr_socket_timeout_get(backend->sock, &backend_timeout); apr_socket_timeout_get(ap_get_conn_socket(c), &client_timeout); if (backend_timeout >= 0 && backend_timeout > client_timeout) { tunnel->timeout = backend_timeout; } else { tunnel->timeout = client_timeout; } /* Let proxy tunnel forward everything */ status = ap_proxy_tunnel_run(tunnel); /* We are done with both connections */ return DONE; } if (interim_response) { /* Already forwarded above, read next response */ continue; } /* Moved the fixups of Date headers and those affected by * ProxyPassReverse/etc from here to ap_proxy_read_headers */ /* PR 41646: get HEAD right with ProxyErrorOverride */ if (ap_proxy_should_override(dconf, proxy_status)) { if (proxy_status == HTTP_UNAUTHORIZED) { 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_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01109) "origin server sent 401 without " "WWW-Authenticate header"); } } /* clear r->status for override error, otherwise ErrorDocument * thinks that this is a recursive error, and doesn't find the * custom error page */ r->status = HTTP_OK; /* Discard body, if one is expected */ if (!r->header_only && !AP_STATUS_IS_HEADER_ONLY(proxy_status)) { const char *tmp; /* Add minimal headers needed to allow http_in filter * detecting end of body without waiting for a timeout. */ if ((tmp = apr_table_get(r->headers_out, "Transfer-Encoding"))) { apr_table_set(backend->r->headers_in, "Transfer-Encoding", tmp); } else if ((tmp = apr_table_get(r->headers_out, "Content-Length"))) { apr_table_set(backend->r->headers_in, "Content-Length", tmp); } else if (te) { apr_table_set(backend->r->headers_in, "Transfer-Encoding", te); } ap_discard_request_body(backend->r); } /* * prevent proxy_handler() from treating this as an * internal error. */ apr_table_setn(r->notes, "proxy-error-override", "1"); return proxy_status; } /* Forward back Upgrade header if it matches the configured one(s), it * may be an HTTP_UPGRADE_REQUIRED response or some other status where * Upgrade makes sense to negotiate the protocol by other means. */ if (upgrade && ap_proxy_worker_can_upgrade(p, worker, upgrade, (*req->proto == 'w') ? "WebSocket" : NULL)) { apr_table_setn(r->headers_out, "Connection", "Upgrade"); apr_table_setn(r->headers_out, "Upgrade", apr_pstrdup(p, upgrade)); } 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 */ (proxy_status != HTTP_NO_CONTENT) && /* not 204 */ (proxy_status != HTTP_NOT_MODIFIED)) { /* not 304 */ apr_read_type_e mode; int finish; /* 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. */ backend->r->headers_in = apr_table_clone(backend->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(backend->r->headers_in, "Transfer-Encoding")) { apr_table_add(backend->r->headers_in, "Transfer-Encoding", te); } apr_table_unset(r->headers_out,"Transfer-Encoding"); ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, "start body send"); /* read the body, pass it to the output filters */ /* Handle the case where the error document is itself reverse * proxied and was successful. We must maintain any previous * error status so that an underlying error (eg HTTP_NOT_FOUND) * doesn't become an HTTP_OK. */ if (ap_proxy_should_override(dconf, original_status)) { r->status = original_status; r->status_line = original_status_line; } mode = APR_NONBLOCK_READ; finish = FALSE; do { apr_off_t readbytes; apr_status_t rv; rv = ap_get_brigade(backend->r->input_filters, bb, AP_MODE_READBYTES, mode, req->sconf->io_buffer_size); /* ap_get_brigade will return success with an empty brigade * for a non-blocking read which would block: */ if (mode == APR_NONBLOCK_READ && (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) { backend->close = 1; 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_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01110) "error reading response"); apr_brigade_cleanup(bb); 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; if (!apr_is_empty_table(backend->r->trailers_in)) { apr_table_do(add_trailers, r->trailers_out, backend->r->trailers_in, NULL); apr_table_clear(backend->r->trailers_in); } apr_brigade_length(bb, 0, &readbytes); backend->worker->s->read += readbytes; #if DEBUGGING { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01111) "readbytes: %#x", readbytes); } #endif /* sanity check */ if (APR_BRIGADE_EMPTY(bb)) { break; } /* Switch the allocator lifetime of the buckets */ ap_proxy_buckets_lifetime_transform(r, bb, pass_bb); /* found the last brigade? */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(pass_bb))) { /* signal that we must leave */ finish = TRUE; /* the brigade may contain transient buckets that contain * data that lives only as long as the backend connection. * Force a setaside so these transient buckets become heap * buckets that live as long as the request. */ for (e = APR_BRIGADE_FIRST(pass_bb); e != APR_BRIGADE_SENTINEL(pass_bb); e = APR_BUCKET_NEXT(e)) { apr_bucket_setaside(e, r->pool); } /* finally it is safe to clean up the brigade from the * connection pool, as we have forced a setaside on all * buckets. */ apr_brigade_cleanup(bb); /* make sure we release the backend connection as soon * as we know we are done, so that the backend isn't * left waiting for a slow client to eventually * acknowledge the data. */ ap_proxy_release_connection(backend->worker->s->scheme, backend, r->server); /* Ensure that the backend is not reused */ req->backend = NULL; } /* try send what we read */ if (ap_pass_brigade(r->output_filters, pass_bb) != APR_SUCCESS || c->aborted) { /* Ack! Phbtt! Die! User aborted! */ /* Only close backend if we haven't got all from the * backend. Furthermore if req->backend is NULL it is no * longer safe to fiddle around with backend as it might * be already in use by another thread. */ if (req->backend) { /* this causes socket close below */ req->backend->close = 1; } finish = TRUE; } /* make sure we always clean up after ourselves */ apr_brigade_cleanup(pass_bb); apr_brigade_cleanup(bb); } while (!finish); ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "end body send"); } else { ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "header only"); /* make sure we release the backend connection as soon * as we know we are done, so that the backend isn't * left waiting for a slow client to eventually * acknowledge the data. */ ap_proxy_release_connection(backend->worker->s->scheme, backend, r->server); /* Ensure that the backend is not reused */ req->backend = NULL; /* Pass EOS bucket down the filter chain. */ e = apr_bucket_eos_create(c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, e); ap_pass_brigade(r->output_filters, bb); apr_brigade_cleanup(bb); } } while (interim_response && (interim_response < AP_MAX_INTERIM_RESPONSES)); /* We have to cleanup bb brigade, because buckets inserted to it could be * created from scpool and this pool can be freed before this brigade. */ apr_brigade_cleanup(bb); /* 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; } 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; const char *scheme; const char *u = url; proxy_http_req_t *req = NULL; proxy_conn_rec *backend = NULL; apr_bucket_brigade *input_brigade = NULL; int is_ssl = 0; conn_rec *c = r->connection; proxy_dir_conf *dconf; int retry = 0; char *locurl = url; int toclose = 0; /* * Use a shorter-lived pool to reduce memory usage * and avoid a memory leak */ apr_pool_t *p = r->pool; apr_uri_t *uri; scheme = get_url_scheme(&u, &is_ssl); if (!scheme && proxyname && strncasecmp(url, "ftp:", 4) == 0) { u = url + 4; scheme = "ftp"; is_ssl = 0; } if (!scheme || u[0] != '/' || u[1] != '/' || u[2] == '\0') { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01113) "HTTP: declining URL %s", url); return DECLINED; /* only interested in HTTP, WS or FTP via proxy */ } if (is_ssl && !ap_ssl_has_outgoing_handlers()) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01112) "HTTP: declining URL %s (mod_ssl not configured?)", url); return DECLINED; } ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "HTTP: serving URL %s", url); /* create space for state information */ if ((status = ap_proxy_acquire_connection(scheme, &backend, worker, r->server)) != OK) { return status; } backend->is_ssl = is_ssl; req = apr_pcalloc(p, sizeof(*req)); req->p = p; req->r = r; req->sconf = conf; req->worker = worker; req->backend = backend; req->proto = scheme; req->bucket_alloc = c->bucket_alloc; req->rb_method = RB_INIT; dconf = ap_get_module_config(r->per_dir_config, &proxy_module); if (apr_table_get(r->subprocess_env, "force-proxy-request-1.0")) { req->force10 = 1; } else if (*worker->s->upgrade || *req->proto == 'w') { /* Forward Upgrade header if it matches the configured one(s), * the default being "WebSocket" for ws[s] schemes. */ const char *upgrade = apr_table_get(r->headers_in, "Upgrade"); if (upgrade && ap_proxy_worker_can_upgrade(p, worker, upgrade, (*req->proto == 'w') ? "WebSocket" : NULL)) { req->upgrade = upgrade; } } /* We possibly reuse input data prefetched in previous call(s), e.g. for a * balancer fallback scenario, and in this case the 100 continue settings * should be consistent between balancer members. If not, we need to ignore * Proxy100Continue on=>off once we tried to prefetch already, otherwise * the HTTP_IN filter won't send 100 Continue for us anymore, and we might * deadlock with the client waiting for each other. Note that off=>on is * not an issue because in this case r->expecting_100 is false (the 100 * Continue is out already), but we make sure that prefetch will be * nonblocking to avoid passing more time there. */ apr_pool_userdata_get((void **)&input_brigade, "proxy-req-input", p); /* Should we handle end-to-end or ping 100-continue? */ if (!req->force10 && ((r->expecting_100 && (dconf->forward_100_continue || input_brigade)) || PROXY_SHOULD_PING_100_CONTINUE(worker, r))) { /* Tell ap_proxy_create_hdrbrgd() to preserve/add the Expect header */ apr_table_setn(r->notes, "proxy-100-continue", "1"); req->do_100_continue = 1; } /* Should we block while prefetching the body or try nonblocking and flush * data to the backend ASAP? */ if (input_brigade || req->do_100_continue || apr_table_get(r->subprocess_env, "proxy-prefetch-nonblocking")) { req->prefetch_nonblocking = 1; } /* * 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 expect 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 */ uri = apr_palloc(p, sizeof(*uri)); if ((status = ap_proxy_determine_connection(p, r, conf, worker, backend, uri, &locurl, proxyname, proxyport, req->server_portstr, sizeof(req->server_portstr)))) goto cleanup; /* The header is always (re-)built since it depends on worker settings, * but the body can be fetched only once (even partially), so it's saved * in between proxy_http_handler() calls should we come back here. */ req->header_brigade = apr_brigade_create(p, req->bucket_alloc); if (input_brigade == NULL) { input_brigade = apr_brigade_create(p, req->bucket_alloc); apr_pool_userdata_setn(input_brigade, "proxy-req-input", NULL, p); } req->input_brigade = input_brigade; /* Prefetch (nonlocking) the request body so to increase the chance to get * the whole (or enough) body and determine Content-Length vs chunked or * spooled. By doing this before connecting or reusing the backend, we want * to minimize the delay between this connection is considered alive and * the first bytes sent (should the client's link be slow or some input * filter retain the data). This is a best effort to prevent the backend * from closing (from under us) what it thinks is an idle connection, hence * to reduce to the minimum the unavoidable local is_socket_connected() vs * remote keepalive race condition. */ if ((status = ap_proxy_http_prefetch(req, uri, locurl)) != OK) goto cleanup; /* We need to reset backend->close now, since ap_proxy_http_prefetch() set * it to disable the reuse of the connection *after* this request (no keep- * alive), not to close any reusable connection before this request. However * assure what is expected later by using a local flag and do the right thing * when ap_proxy_connect_backend() below provides the connection to close. */ toclose = backend->close; backend->close = 0; while (retry < 2) { if (retry) { char *newurl = url; /* Step One (again): (Re)Determine Who To Connect To */ if ((status = ap_proxy_determine_connection(p, r, conf, worker, backend, uri, &newurl, proxyname, proxyport, req->server_portstr, sizeof(req->server_portstr)))) break; /* The code assumes locurl is not changed during the loop, or * ap_proxy_http_prefetch() would have to be called every time, * and header_brigade be changed accordingly... */ AP_DEBUG_ASSERT(strcmp(newurl, locurl) == 0); } /* Step Two: Make the Connection */ if (ap_proxy_check_connection(scheme, backend, r->server, 1, PROXY_CHECK_CONN_EMPTY) && ap_proxy_connect_backend(scheme, backend, worker, r->server)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01114) "HTTP: failed to make connection to backend: %s", backend->hostname); status = HTTP_SERVICE_UNAVAILABLE; break; } /* Step Three: Create conn_rec */ if ((status = ap_proxy_connection_create_ex(scheme, backend, r)) != OK) break; req->origin = backend->connection; /* Don't recycle the connection if prefetch (above) told not to do so */ if (toclose) { backend->close = 1; req->origin->keepalive = AP_CONN_CLOSE; } /* Step Four: Send the Request * On the off-chance that we forced a 100-Continue as a * kinda HTTP ping test, allow for retries */ status = ap_proxy_http_request(req); if (status != OK) { if (req->do_100_continue && status == HTTP_SERVICE_UNAVAILABLE) { ap_log_rerror(APLOG_MARK, APLOG_INFO, status, r, APLOGNO(01115) "HTTP: 100-Continue failed to %pI (%s:%d)", worker->cp->addr, worker->s->hostname_ex, (int)worker->s->port); backend->close = 1; retry++; continue; } break; } /* Step Five: Receive the Response... Fall thru to cleanup */ status = ap_proxy_http_process_response(req); break; } /* Step Six: Clean Up */ cleanup: if (req->backend) { if (status != OK) req->backend->close = 1; ap_proxy_http_cleanup(scheme, r, req->backend); } return status; } /* post_config hook: */ static int proxy_http_post_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) { /* proxy_http_post_config() will be called twice during startup. So, don't * set up the static data the 1st time through. */ if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) { return OK; } ap_proxy_clear_connection_fn = APR_RETRIEVE_OPTIONAL_FN(ap_proxy_clear_connection); if (!ap_proxy_clear_connection_fn) { ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02477) "mod_proxy must be loaded for mod_proxy_http"); return !OK; } return OK; } static void ap_proxy_http_register_hook(apr_pool_t *p) { ap_hook_post_config(proxy_http_post_config, NULL, NULL, APR_HOOK_MIDDLE); 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); } AP_DECLARE_MODULE(proxy_http) = { 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 */ };