Pull out duplicated code to proxy_util...

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1453875 13f79535-47bb-0310-9956-ffa450edef68

modules/proxy/proxy_util.c

@@ -2954,3 +2954,329 @@ void proxy_util_register_hooks(apr_pool_t *p)
 {
     APR_REGISTER_OPTIONAL_FN(ap_proxy_retry_worker);
 }
+
+/* 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 int clear_conn_headers(void *data, const char *key, const char *val)
+{
+    apr_table_t *headers = ((header_dptr*)data)->table;
+    apr_pool_t *pool = ((header_dptr*)data)->pool;
+    const char *name;
+    char *next = apr_pstrdup(pool, val);
+    while (*next) {
+        name = next;
+        while (*next && !apr_isspace(*next) && (*next != ',')) {
+            ++next;
+        }
+        while (*next && (apr_isspace(*next) || (*next == ','))) {
+            *next++ = '\0';
+        }
+        apr_table_unset(headers, name);
+    }
+    return 1;
+}
+
+static void proxy_clear_connection(apr_pool_t *p, apr_table_t *headers)
+{
+    header_dptr x;
+    x.pool = p;
+    x.table = headers;
+    apr_table_unset(headers, "Proxy-Connection");
+    apr_table_do(clear_conn_headers, &x, headers, "Connection", NULL);
+    apr_table_unset(headers, "Connection");
+}
+
+PROXY_DECLARE(int) ap_proxy_create_hdrbrgd(apr_pool_t *p,
+                                            apr_bucket_brigade *header_brigade,
+                                            request_rec *r,
+                                            proxy_conn_rec *p_conn,
+                                            proxy_worker *worker,
+                                            proxy_server_conf *conf,
+                                            apr_uri_t *uri,
+                                            char *url, char *server_portstr,
+                                            char **old_cl_val,
+                                            char **old_te_val)
+{
+    conn_rec *c = r->connection;
+    int counter;
+    char *buf;
+    const apr_array_header_t *headers_in_array;
+    const apr_table_entry_t *headers_in;
+    apr_table_t *headers_in_copy;
+    apr_bucket *e;
+    int do_100_continue;
+    conn_rec *origin = p_conn->connection;
+    proxy_dir_conf *dconf = ap_get_module_config(r->per_dir_config, &proxy_module);
+
+    /*
+     * To be compliant, we only use 100-Continue for requests with bodies.
+     * We also make sure we won't be talking HTTP/1.0 as well.
+     */
+    do_100_continue = (worker->s->ping_timeout_set
+                       && ap_request_has_body(r)
+                       && (PROXYREQ_REVERSE == r->proxyreq)
+                       && !(apr_table_get(r->subprocess_env, "force-proxy-request-1.0")));
+
+    if (apr_table_get(r->subprocess_env, "force-proxy-request-1.0")) {
+        /*
+         * According to RFC 2616 8.2.3 we are not allowed to forward an
+         * Expect: 100-continue to an HTTP/1.0 server. Instead we MUST return
+         * a HTTP_EXPECTATION_FAILED
+         */
+        if (r->expecting_100) {
+            return HTTP_EXPECTATION_FAILED;
+        }
+        buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.0" CRLF, NULL);
+        p_conn->close = 1;
+    } else {
+        buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.1" CRLF, NULL);
+    }
+    if (apr_table_get(r->subprocess_env, "proxy-nokeepalive")) {
+        origin->keepalive = AP_CONN_CLOSE;
+        p_conn->close = 1;
+    }
+    ap_xlate_proto_to_ascii(buf, strlen(buf));
+    e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
+    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
+    if (dconf->preserve_host == 0) {
+        if (ap_strchr_c(uri->hostname, ':')) { /* if literal IPv6 address */
+            if (uri->port_str && uri->port != DEFAULT_HTTP_PORT) {
+                buf = apr_pstrcat(p, "Host: [", uri->hostname, "]:",
+                                  uri->port_str, CRLF, NULL);
+            } else {
+                buf = apr_pstrcat(p, "Host: [", uri->hostname, "]", CRLF, NULL);
+            }
+        } else {
+            if (uri->port_str && uri->port != DEFAULT_HTTP_PORT) {
+                buf = apr_pstrcat(p, "Host: ", uri->hostname, ":",
+                                  uri->port_str, CRLF, NULL);
+            } else {
+                buf = apr_pstrcat(p, "Host: ", uri->hostname, CRLF, NULL);
+            }
+        }
+    }
+    else {
+        /* don't want to use r->hostname, as the incoming header might have a
+         * port attached
+         */
+        const char* hostname = apr_table_get(r->headers_in,"Host");
+        if (!hostname) {
+            hostname =  r->server->server_hostname;
+            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01092)
+                          "no HTTP 0.9 request (with no host line) "
+                          "on incoming request and preserve host set "
+                          "forcing hostname to be %s for uri %s",
+                          hostname, r->uri);
+        }
+        buf = apr_pstrcat(p, "Host: ", hostname, CRLF, NULL);
+    }
+    ap_xlate_proto_to_ascii(buf, strlen(buf));
+    e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
+    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
+
+    /* handle Via */
+    if (conf->viaopt == via_block) {
+        /* Block all outgoing Via: headers */
+        apr_table_unset(r->headers_in, "Via");
+    } else if (conf->viaopt != via_off) {
+        const char *server_name = ap_get_server_name(r);
+        /* If USE_CANONICAL_NAME_OFF was configured for the proxy virtual host,
+         * then the server name returned by ap_get_server_name() is the
+         * origin server name (which does make too much sense with Via: headers)
+         * so we use the proxy vhost's name instead.
+         */
+        if (server_name == r->hostname)
+            server_name = r->server->server_hostname;
+        /* Create a "Via:" request header entry and merge it */
+        /* Generate outgoing Via: header with/without server comment: */
+        apr_table_mergen(r->headers_in, "Via",
+                         (conf->viaopt == via_full)
+                         ? apr_psprintf(p, "%d.%d %s%s (%s)",
+                                        HTTP_VERSION_MAJOR(r->proto_num),
+                                        HTTP_VERSION_MINOR(r->proto_num),
+                                        server_name, server_portstr,
+                                        AP_SERVER_BASEVERSION)
+                         : apr_psprintf(p, "%d.%d %s%s",
+                                        HTTP_VERSION_MAJOR(r->proto_num),
+                                        HTTP_VERSION_MINOR(r->proto_num),
+                                        server_name, server_portstr)
+                         );
+    }
+
+    /* Use HTTP/1.1 100-Continue as quick "HTTP ping" test
+     * to backend
+     */
+    if (do_100_continue) {
+        apr_table_mergen(r->headers_in, "Expect", "100-Continue");
+        r->expecting_100 = 1;
+    }
+
+    /* X-Forwarded-*: handling
+     *
+     * XXX Privacy Note:
+     * -----------------
+     *
+     * These request headers are only really useful when the mod_proxy
+     * is used in a reverse proxy configuration, so that useful info
+     * about the client can be passed through the reverse proxy and on
+     * to the backend server, which may require the information to
+     * function properly.
+     *
+     * In a forward proxy situation, these options are a potential
+     * privacy violation, as information about clients behind the proxy
+     * are revealed to arbitrary servers out there on the internet.
+     *
+     * The HTTP/1.1 Via: header is designed for passing client
+     * information through proxies to a server, and should be used in
+     * a forward proxy configuation instead of X-Forwarded-*. See the
+     * ProxyVia option for details.
+     */
+    if (dconf->add_forwarded_headers) {
+        if (PROXYREQ_REVERSE == r->proxyreq) {
+            const char *buf;
+
+            /* Add X-Forwarded-For: so that the upstream has a chance to
+             * determine, where the original request came from.
+             */
+            apr_table_mergen(r->headers_in, "X-Forwarded-For",
+                             r->useragent_ip);
+
+            /* Add X-Forwarded-Host: so that upstream knows what the
+             * original request hostname was.
+             */
+            if ((buf = apr_table_get(r->headers_in, "Host"))) {
+                apr_table_mergen(r->headers_in, "X-Forwarded-Host", buf);
+            }
+
+            /* Add X-Forwarded-Server: so that upstream knows what the
+             * name of this proxy server is (if there are more than one)
+             * XXX: This duplicates Via: - do we strictly need it?
+             */
+            apr_table_mergen(r->headers_in, "X-Forwarded-Server",
+                             r->server->server_hostname);
+        }
+    }
+
+    proxy_run_fixups(r);
+    /*
+     * Make a copy of the headers_in table before clearing the connection
+     * headers as we need the connection headers later in the http output
+     * filter to prepare the correct response headers.
+     *
+     * Note: We need to take r->pool for apr_table_copy as the key / value
+     * pairs in r->headers_in have been created out of r->pool and
+     * p might be (and actually is) a longer living pool.
+     * This would trigger the bad pool ancestry abort in apr_table_copy if
+     * apr is compiled with APR_POOL_DEBUG.
+     */
+    headers_in_copy = apr_table_copy(r->pool, r->headers_in);
+    proxy_clear_connection(p, headers_in_copy);
+    /* send request headers */
+    headers_in_array = apr_table_elts(headers_in_copy);
+    headers_in = (const apr_table_entry_t *) headers_in_array->elts;
+    for (counter = 0; counter < headers_in_array->nelts; counter++) {
+        if (headers_in[counter].key == NULL
+            || headers_in[counter].val == NULL
+
+            /* Already sent */
+            || !strcasecmp(headers_in[counter].key, "Host")
+
+            /* Clear out hop-by-hop request headers not to send
+             * RFC2616 13.5.1 says we should strip these headers
+             */
+            || !strcasecmp(headers_in[counter].key, "Keep-Alive")
+            || !strcasecmp(headers_in[counter].key, "TE")
+            || !strcasecmp(headers_in[counter].key, "Trailer")
+            || !strcasecmp(headers_in[counter].key, "Upgrade")
+
+            ) {
+            continue;
+        }
+        /* Do we want to strip Proxy-Authorization ?
+         * If we haven't used it, then NO
+         * If we have used it then MAYBE: RFC2616 says we MAY propagate it.
+         * So let's make it configurable by env.
+         */
+        if (!strcasecmp(headers_in[counter].key,"Proxy-Authorization")) {
+            if (r->user != NULL) { /* we've authenticated */
+                if (!apr_table_get(r->subprocess_env, "Proxy-Chain-Auth")) {
+                    continue;
+                }
+            }
+        }
+
+        /* Skip Transfer-Encoding and Content-Length for now.
+         */
+        if (!strcasecmp(headers_in[counter].key, "Transfer-Encoding")) {
+            *old_te_val = headers_in[counter].val;
+            continue;
+        }
+        if (!strcasecmp(headers_in[counter].key, "Content-Length")) {
+            *old_cl_val = headers_in[counter].val;
+            continue;
+        }
+
+        /* for sub-requests, ignore freshness/expiry headers */
+        if (r->main) {
+            if (    !strcasecmp(headers_in[counter].key, "If-Match")
+                || !strcasecmp(headers_in[counter].key, "If-Modified-Since")
+                || !strcasecmp(headers_in[counter].key, "If-Range")
+                || !strcasecmp(headers_in[counter].key, "If-Unmodified-Since")
+                || !strcasecmp(headers_in[counter].key, "If-None-Match")) {
+                continue;
+            }
+        }
+
+        buf = apr_pstrcat(p, headers_in[counter].key, ": ",
+                          headers_in[counter].val, CRLF,
+                          NULL);
+        ap_xlate_proto_to_ascii(buf, strlen(buf));
+        e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
+        APR_BRIGADE_INSERT_TAIL(header_brigade, e);
+    }
+    return OK;
+}
+
+PROXY_DECLARE(int) ap_proxy_pass_brigade(apr_bucket_alloc_t *bucket_alloc,
+                                         request_rec *r, proxy_conn_rec *p_conn,
+                                         conn_rec *origin, apr_bucket_brigade *bb,
+                                         int flush)
+{
+    apr_status_t status;
+    apr_off_t transferred;
+
+    if (flush) {
+        apr_bucket *e = apr_bucket_flush_create(bucket_alloc);
+        APR_BRIGADE_INSERT_TAIL(bb, e);
+    }
+    apr_brigade_length(bb, 0, &transferred);
+    if (transferred != -1)
+        p_conn->worker->s->transferred += transferred;
+    status = ap_pass_brigade(origin->output_filters, bb);
+    if (status != APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01084)
+                      "pass request body failed to %pI (%s)",
+                      p_conn->addr, p_conn->hostname);
+        if (origin->aborted) {
+            const char *ssl_note;
+
+            if (((ssl_note = apr_table_get(origin->notes, "SSL_connect_rv"))
+                 != NULL) && (strcmp(ssl_note, "err") == 0)) {
+                return ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
+                                     "Error during SSL Handshake with"
+                                     " remote server");
+            }
+            return APR_STATUS_IS_TIMEUP(status) ? HTTP_GATEWAY_TIME_OUT : HTTP_BAD_GATEWAY;
+        }
+        else {
+            return HTTP_BAD_REQUEST;
+        }
+    }
+    apr_brigade_cleanup(bb);
+    return OK;
+}