diff options
Diffstat (limited to 'modules/proxy/mod_proxy_http.c')
| -rw-r--r-- | modules/proxy/mod_proxy_http.c | 2145 |
1 files changed, 2145 insertions, 0 deletions
diff --git a/modules/proxy/mod_proxy_http.c b/modules/proxy/mod_proxy_http.c new file mode 100644 index 0000000..1842c49 --- /dev/null +++ b/modules/proxy/mod_proxy_http.c @@ -0,0 +1,2145 @@ +/* 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 + /* <trailers> */ + 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 */ +}; + |