Adding upstream version 2.4.38.upstream/2.4.38upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 674 insertions, 0 deletions

diff --git a/modules/http2/mod_proxy_http2.c b/modules/http2/mod_proxy_http2.c
new file mode 100644
index 0000000..a7e0dcd
--- /dev/null
+++ b/modules/http2/mod_proxy_http2.c
@@ -0,0 +1,674 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <nghttp2/nghttp2.h>
+
+#include <httpd.h>
+#include <mod_proxy.h>
+#include "mod_http2.h"
+
+
+#include "mod_proxy_http2.h"
+#include "h2_request.h"
+#include "h2_proxy_util.h"
+#include "h2_version.h"
+#include "h2_proxy_session.h"
+
+#define H2MIN(x,y) ((x) < (y) ? (x) : (y))
+
+static void register_hook(apr_pool_t *p);
+
+AP_DECLARE_MODULE(proxy_http2) = {
+    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 */
+    register_hook,     /* register hooks */
+#if defined(AP_MODULE_FLAG_NONE)
+    AP_MODULE_FLAG_ALWAYS_MERGE
+#endif
+};
+
+/* Optional functions from mod_http2 */
+static int (*is_h2)(conn_rec *c);
+static apr_status_t (*req_engine_push)(const char *name, request_rec *r, 
+                                       http2_req_engine_init *einit);
+static apr_status_t (*req_engine_pull)(h2_req_engine *engine, 
+                                       apr_read_type_e block, 
+                                       int capacity, 
+                                       request_rec **pr);
+static void (*req_engine_done)(h2_req_engine *engine, conn_rec *r_conn,
+                               apr_status_t status);
+                                       
+typedef struct h2_proxy_ctx {
+    conn_rec *owner;
+    apr_pool_t *pool;
+    request_rec *rbase;
+    server_rec *server;
+    const char *proxy_func;
+    char server_portstr[32];
+    proxy_conn_rec *p_conn;
+    proxy_worker *worker;
+    proxy_server_conf *conf;
+    
+    h2_req_engine *engine;
+    const char *engine_id;
+    const char *engine_type;
+    apr_pool_t *engine_pool;    
+    apr_size_t req_buffer_size;
+    h2_proxy_fifo *requests;
+    int capacity;
+    
+    unsigned standalone : 1;
+    unsigned is_ssl : 1;
+    unsigned flushall : 1;
+    
+    apr_status_t r_status;     /* status of our first request work */
+    h2_proxy_session *session; /* current http2 session against backend */
+} h2_proxy_ctx;
+
+static int h2_proxy_post_config(apr_pool_t *p, apr_pool_t *plog,
+                                apr_pool_t *ptemp, server_rec *s)
+{
+    void *data = NULL;
+    const char *init_key = "mod_proxy_http2_init_counter";
+    nghttp2_info *ngh2;
+    apr_status_t status = APR_SUCCESS;
+    (void)plog;(void)ptemp;
+    
+    apr_pool_userdata_get(&data, init_key, s->process->pool);
+    if ( data == NULL ) {
+        apr_pool_userdata_set((const void *)1, init_key,
+                              apr_pool_cleanup_null, s->process->pool);
+        return APR_SUCCESS;
+    }
+    
+    ngh2 = nghttp2_version(0);
+    ap_log_error( APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(03349)
+                 "mod_proxy_http2 (v%s, nghttp2 %s), initializing...",
+                 MOD_HTTP2_VERSION, ngh2? ngh2->version_str : "unknown");
+    
+    is_h2 = APR_RETRIEVE_OPTIONAL_FN(http2_is_h2);
+    req_engine_push = APR_RETRIEVE_OPTIONAL_FN(http2_req_engine_push);
+    req_engine_pull = APR_RETRIEVE_OPTIONAL_FN(http2_req_engine_pull);
+    req_engine_done = APR_RETRIEVE_OPTIONAL_FN(http2_req_engine_done);
+    
+    /* we need all of them */
+    if (!req_engine_push || !req_engine_pull || !req_engine_done) {
+        req_engine_push = NULL;
+        req_engine_pull = NULL;
+        req_engine_done = NULL;
+    }
+    
+    return status;
+}
+
+/**
+ * canonicalize the url into the request, if it is meant for us.
+ * slightly modified copy from mod_http
+ */
+static int proxy_http2_canon(request_rec *r, char *url)
+{
+    char *host, *path, sport[7];
+    char *search = NULL;
+    const char *err;
+    const char *scheme;
+    const char *http_scheme;
+    apr_port_t port, def_port;
+
+    /* ap_port_of_scheme() */
+    if (ap_cstr_casecmpn(url, "h2c:", 4) == 0) {
+        url += 4;
+        scheme = "h2c";
+        http_scheme = "http";
+    }
+    else if (ap_cstr_casecmpn(url, "h2:", 3) == 0) {
+        url += 3;
+        scheme = "h2";
+        http_scheme = "https";
+    }
+    else {
+        return DECLINED;
+    }
+    port = def_port = ap_proxy_port_of_scheme(http_scheme);
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                  "HTTP2: canonicalising URL %s", 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(03350)
+                      "error parsing URL %s: %s", url, err);
+        return HTTP_BAD_REQUEST;
+    }
+
+    /*
+     * now parse path/search args, according to rfc1738:
+     * process the path.
+     *
+     * In a reverse proxy, our URL has been processed, so canonicalise
+     * unless proxy-nocanon is set to say it's raw
+     * In a forward proxy, we have and MUST NOT MANGLE the original.
+     */
+    switch (r->proxyreq) {
+    default: /* wtf are we doing here? */
+    case PROXYREQ_REVERSE:
+        if (apr_table_get(r->notes, "proxy-nocanon")) {
+            path = url;   /* this is the raw path */
+        }
+        else {
+            path = ap_proxy_canonenc(r->pool, url, (int)strlen(url),
+                                     enc_path, 0, r->proxyreq);
+            search = r->args;
+        }
+        break;
+    case PROXYREQ_PROXY:
+        path = url;
+        break;
+    }
+
+    if (path == NULL) {
+        return HTTP_BAD_REQUEST;
+    }
+
+    if (port != def_port) {
+        apr_snprintf(sport, sizeof(sport), ":%d", port);
+    }
+    else {
+        sport[0] = '\0';
+    }
+
+    if (ap_strchr_c(host, ':')) { /* if literal IPv6 address */
+        host = apr_pstrcat(r->pool, "[", host, "]", NULL);
+    }
+    r->filename = apr_pstrcat(r->pool, "proxy:", scheme, "://", host, sport,
+            "/", path, (search) ? "?" : "", (search) ? search : "", NULL);
+    return OK;
+}
+
+static void out_consumed(void *baton, conn_rec *c, apr_off_t bytes)
+{
+    h2_proxy_ctx *ctx = baton;
+    
+    if (ctx->session) {
+        h2_proxy_session_update_window(ctx->session, c, bytes);
+    }
+}
+
+static apr_status_t proxy_engine_init(h2_req_engine *engine, 
+                                        const char *id, 
+                                        const char *type,
+                                        apr_pool_t *pool, 
+                                        apr_size_t req_buffer_size,
+                                        request_rec *r,
+                                        http2_output_consumed **pconsumed,
+                                        void **pctx)
+{
+    h2_proxy_ctx *ctx = ap_get_module_config(r->connection->conn_config, 
+                                             &proxy_http2_module);
+    if (!ctx) {
+        ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(03368)
+                      "h2_proxy_session, engine init, no ctx found");
+        return APR_ENOTIMPL;
+    }
+    
+    ctx->pool = pool;
+    ctx->engine = engine;
+    ctx->engine_id = id;
+    ctx->engine_type = type;
+    ctx->engine_pool = pool;
+    ctx->req_buffer_size = req_buffer_size;
+    ctx->capacity = H2MIN(100, h2_proxy_fifo_capacity(ctx->requests));
+    
+    *pconsumed = out_consumed;
+    *pctx = ctx;
+    return APR_SUCCESS;
+}
+
+static apr_status_t add_request(h2_proxy_session *session, request_rec *r)
+{
+    h2_proxy_ctx *ctx = session->user_data;
+    const char *url;
+    apr_status_t status;
+
+    url = apr_table_get(r->notes, H2_PROXY_REQ_URL_NOTE);
+    apr_table_setn(r->notes, "proxy-source-port", apr_psprintf(r->pool, "%hu",
+                   ctx->p_conn->connection->local_addr->port));
+    status = h2_proxy_session_submit(session, url, r, ctx->standalone);
+    if (status != APR_SUCCESS) {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, status, r->connection, APLOGNO(03351)
+                      "pass request body failed to %pI (%s) from %s (%s)",
+                      ctx->p_conn->addr, ctx->p_conn->hostname ? 
+                      ctx->p_conn->hostname: "", session->c->client_ip, 
+                      session->c->remote_host ? session->c->remote_host: "");
+    }
+    return status;
+}
+
+static void request_done(h2_proxy_ctx *ctx, request_rec *r,
+                         apr_status_t status, int touched)
+{   
+    const char *task_id = apr_table_get(r->connection->notes, H2_TASK_ID_NOTE);
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, status, r->connection, 
+                  "h2_proxy_session(%s): request done %s, touched=%d",
+                  ctx->engine_id, task_id, touched);
+    if (status != APR_SUCCESS) {
+        if (!touched) {
+            /* untouched request, need rescheduling */
+            status = h2_proxy_fifo_push(ctx->requests, r);
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, r->connection, 
+                          APLOGNO(03369)
+                          "h2_proxy_session(%s): rescheduled request %s",
+                          ctx->engine_id, task_id);
+            return;
+        }
+        else {
+            const char *uri;
+            uri = apr_uri_unparse(r->pool, &r->parsed_uri, 0);
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, r->connection, 
+                          APLOGNO(03471) "h2_proxy_session(%s): request %s -> %s "
+                          "not complete, cannot repeat", 
+                          ctx->engine_id, task_id, uri);
+        }
+    }
+    
+    if (r == ctx->rbase) {
+        ctx->r_status = ((status == APR_SUCCESS)? APR_SUCCESS
+                         : HTTP_SERVICE_UNAVAILABLE);
+    }
+    
+    if (req_engine_done && ctx->engine) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, r->connection, 
+                      APLOGNO(03370)
+                      "h2_proxy_session(%s): finished request %s",
+                      ctx->engine_id, task_id);
+        req_engine_done(ctx->engine, r->connection, status);
+    }
+}    
+
+static void session_req_done(h2_proxy_session *session, request_rec *r,
+                             apr_status_t status, int touched)
+{
+    request_done(session->user_data, r, status, touched);
+}
+
+static apr_status_t next_request(h2_proxy_ctx *ctx, int before_leave)
+{
+    if (h2_proxy_fifo_count(ctx->requests) > 0) {
+        return APR_SUCCESS;
+    }
+    else if (req_engine_pull && ctx->engine) {
+        apr_status_t status;
+        request_rec *r = NULL;
+        
+        status = req_engine_pull(ctx->engine, before_leave? 
+                                 APR_BLOCK_READ: APR_NONBLOCK_READ, 
+                                 ctx->capacity, &r);
+        if (status == APR_SUCCESS && r) {
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE3, status, ctx->owner, 
+                          "h2_proxy_engine(%s): pulled request (%s) %s", 
+                          ctx->engine_id, 
+                          before_leave? "before leave" : "regular", 
+                          r->the_request);
+            h2_proxy_fifo_push(ctx->requests, r);
+        }
+        return APR_STATUS_IS_EAGAIN(status)? APR_SUCCESS : status;
+    }
+    return APR_EOF;
+}
+
+static apr_status_t proxy_engine_run(h2_proxy_ctx *ctx) {
+    apr_status_t status = OK;
+    int h2_front;
+    request_rec *r;
+    
+    /* Step Four: Send the Request in a new HTTP/2 stream and
+     * loop until we got the response or encounter errors.
+     */
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, ctx->owner, 
+                  "eng(%s): setup session", ctx->engine_id);
+    h2_front = is_h2? is_h2(ctx->owner) : 0;
+    ctx->session = h2_proxy_session_setup(ctx->engine_id, ctx->p_conn, ctx->conf,
+                                          h2_front, 30, 
+                                          h2_proxy_log2((int)ctx->req_buffer_size), 
+                                          session_req_done);
+    if (!ctx->session) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->owner, 
+                      APLOGNO(03372) "session unavailable");
+        return HTTP_SERVICE_UNAVAILABLE;
+    }
+    
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->owner, APLOGNO(03373)
+                  "eng(%s): run session %s", ctx->engine_id, ctx->session->id);
+    ctx->session->user_data = ctx;
+    
+    while (!ctx->owner->aborted) {
+        if (APR_SUCCESS == h2_proxy_fifo_try_pull(ctx->requests, (void**)&r)) {
+            add_request(ctx->session, r);
+        }
+        
+        status = h2_proxy_session_process(ctx->session);
+        
+        if (status == APR_SUCCESS) {
+            apr_status_t s2;
+            /* ongoing processing, call again */
+            if (ctx->session->remote_max_concurrent > 0
+                && ctx->session->remote_max_concurrent != ctx->capacity) {
+                ctx->capacity = H2MIN((int)ctx->session->remote_max_concurrent, 
+                                      h2_proxy_fifo_capacity(ctx->requests));
+            }
+            s2 = next_request(ctx, 0);
+            if (s2 == APR_ECONNABORTED) {
+                /* master connection gone */
+                ap_log_cerror(APLOG_MARK, APLOG_DEBUG, s2, ctx->owner, 
+                              APLOGNO(03374) "eng(%s): pull request", 
+                              ctx->engine_id);
+                /* give notice that we're leaving and cancel all ongoing
+                 * streams. */
+                next_request(ctx, 1); 
+                h2_proxy_session_cancel_all(ctx->session);
+                h2_proxy_session_process(ctx->session);
+                status = ctx->r_status = APR_SUCCESS;
+                break;
+            }
+            if ((h2_proxy_fifo_count(ctx->requests) == 0) 
+                && h2_proxy_ihash_empty(ctx->session->streams)) {
+                break;
+            }
+        }
+        else {
+            /* end of processing, maybe error */
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, ctx->owner, 
+                          APLOGNO(03375) "eng(%s): end of session %s", 
+                          ctx->engine_id, ctx->session->id);
+            /*
+             * Any open stream of that session needs to
+             * a) be reopened on the new session iff safe to do so
+             * b) reported as done (failed) otherwise
+             */
+            h2_proxy_session_cleanup(ctx->session, session_req_done);
+            break;
+        }
+    }
+    
+    ctx->session->user_data = NULL;
+    ctx->session = NULL;
+    
+    return status;
+}
+
+static apr_status_t push_request_somewhere(h2_proxy_ctx *ctx, request_rec *r)
+{
+    conn_rec *c = ctx->owner;
+    const char *engine_type, *hostname;
+    
+    hostname = (ctx->p_conn->ssl_hostname? 
+                ctx->p_conn->ssl_hostname : ctx->p_conn->hostname);
+    engine_type = apr_psprintf(ctx->pool, "proxy_http2 %s%s", hostname, 
+                               ctx->server_portstr);
+    
+    if (c->master && req_engine_push && r && is_h2 && is_h2(c)) {
+        /* If we are have req_engine capabilities, push the handling of this
+         * request (e.g. slave connection) to a proxy_http2 engine which 
+         * uses the same backend. We may be called to create an engine 
+         * ourself. */
+        if (req_engine_push(engine_type, r, proxy_engine_init) == APR_SUCCESS) {
+            if (ctx->engine == NULL) {
+                /* request has been assigned to an engine in another thread */
+                return SUSPENDED;
+            }
+        }
+    }
+    
+    if (!ctx->engine) {
+        /* No engine was available or has been initialized, handle this
+         * request just by ourself. */
+        ctx->engine_id = apr_psprintf(ctx->pool, "eng-proxy-%ld", c->id);
+        ctx->engine_type = engine_type;
+        ctx->engine_pool = ctx->pool;
+        ctx->req_buffer_size = (32*1024);
+        ctx->standalone = 1;
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, 
+                      "h2_proxy_http2(%ld): setup standalone engine for type %s", 
+                      c->id, engine_type);
+    }
+    else {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, 
+                      "H2: hosting engine %s", ctx->engine_id);
+    }
+
+    return h2_proxy_fifo_push(ctx->requests, r);
+}
+
+static int proxy_http2_handler(request_rec *r, 
+                               proxy_worker *worker,
+                               proxy_server_conf *conf,
+                               char *url, 
+                               const char *proxyname,
+                               apr_port_t proxyport)
+{
+    const char *proxy_func;
+    char *locurl = url, *u;
+    apr_size_t slen;
+    int is_ssl = 0;
+    apr_status_t status;
+    h2_proxy_ctx *ctx;
+    apr_uri_t uri;
+    int reconnects = 0;
+    
+    /* find the scheme */
+    if ((url[0] != 'h' && url[0] != 'H') || url[1] != '2') {
+       return DECLINED;
+    }
+    u = strchr(url, ':');
+    if (u == NULL || u[1] != '/' || u[2] != '/' || u[3] == '\0') {
+       return DECLINED;
+    }
+    slen = (u - url);
+    switch(slen) {
+        case 2:
+            proxy_func = "H2";
+            is_ssl = 1;
+            break;
+        case 3:
+            if (url[2] != 'c' && url[2] != 'C') {
+                return DECLINED;
+            }
+            proxy_func = "H2C";
+            break;
+        default:
+            return DECLINED;
+    }
+    
+    ctx = apr_pcalloc(r->pool, sizeof(*ctx));
+    ctx->owner      = r->connection;
+    ctx->pool       = r->pool;
+    ctx->rbase      = r;
+    ctx->server     = r->server;
+    ctx->proxy_func = proxy_func;
+    ctx->is_ssl     = is_ssl;
+    ctx->worker     = worker;
+    ctx->conf       = conf;
+    ctx->flushall   = apr_table_get(r->subprocess_env, "proxy-flushall")? 1 : 0;
+    ctx->r_status   = HTTP_SERVICE_UNAVAILABLE;
+    
+    h2_proxy_fifo_set_create(&ctx->requests, ctx->pool, 100);
+    
+    ap_set_module_config(ctx->owner->conn_config, &proxy_http2_module, ctx);
+
+    /* scheme says, this is for us. */
+    apr_table_setn(ctx->rbase->notes, H2_PROXY_REQ_URL_NOTE, url);
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, ctx->rbase, 
+                  "H2: serving URL %s", url);
+    
+run_connect:    
+    /* Get a proxy_conn_rec from the worker, might be a new one, might
+     * be one still open from another request, or it might fail if the
+     * worker is stopped or in error. */
+    if ((status = ap_proxy_acquire_connection(ctx->proxy_func, &ctx->p_conn,
+                                              ctx->worker, ctx->server)) != OK) {
+        goto cleanup;
+    }
+
+    ctx->p_conn->is_ssl = ctx->is_ssl;
+    if (ctx->is_ssl && ctx->p_conn->connection) {
+        /* If there are some metadata on the connection (e.g. TLS alert),
+         * let mod_ssl detect them, and create a new connection below.
+         */ 
+        apr_bucket_brigade *tmp_bb;
+        tmp_bb = apr_brigade_create(ctx->rbase->pool, 
+                                    ctx->rbase->connection->bucket_alloc);
+        status = ap_get_brigade(ctx->p_conn->connection->input_filters, tmp_bb,
+                                AP_MODE_SPECULATIVE, APR_NONBLOCK_READ, 1);
+        if (status != APR_SUCCESS && !APR_STATUS_IS_EAGAIN(status)) {
+            ctx->p_conn->close = 1;
+        }
+        apr_brigade_cleanup(tmp_bb);
+    }   
+
+    /* Step One: Determine the URL to connect to (might be a proxy),
+     * initialize the backend accordingly and determine the server 
+     * port string we can expect in responses. */
+    if ((status = ap_proxy_determine_connection(ctx->pool, ctx->rbase, conf, worker, 
+                                                ctx->p_conn, &uri, &locurl, 
+                                                proxyname, proxyport, 
+                                                ctx->server_portstr,
+                                                sizeof(ctx->server_portstr))) != OK) {
+        goto cleanup;
+    }
+    
+    /* If we are not already hosting an engine, try to push the request 
+     * to an already existing engine or host a new engine here. */
+    if (r && !ctx->engine) {
+        ctx->r_status = push_request_somewhere(ctx, r);
+        r = NULL;
+        if (ctx->r_status == SUSPENDED) {
+            /* request was pushed to another thread, leave processing here */
+            goto cleanup;
+        }
+    }
+    
+    /* Step Two: Make the Connection (or check that an already existing
+     * socket is still usable). On success, we have a socket connected to
+     * backend->hostname. */
+    if (ap_proxy_connect_backend(ctx->proxy_func, ctx->p_conn, ctx->worker, 
+                                 ctx->server)) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->owner, APLOGNO(03352)
+                      "H2: failed to make connection to backend: %s",
+                      ctx->p_conn->hostname);
+        goto reconnect;
+    }
+    
+    /* Step Three: Create conn_rec for the socket we have open now. */
+    if (!ctx->p_conn->connection) {
+        status = ap_proxy_connection_create_ex(ctx->proxy_func,
+                                               ctx->p_conn, ctx->rbase);
+        if (status != OK) {
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, ctx->owner, APLOGNO(03353)
+                          "setup new connection: is_ssl=%d %s %s %s", 
+                          ctx->p_conn->is_ssl, ctx->p_conn->ssl_hostname, 
+                          locurl, ctx->p_conn->hostname);
+            goto reconnect;
+        }
+        
+        if (!ctx->p_conn->data) {
+            /* New conection: set a note on the connection what CN is
+             * requested and what protocol we want */
+            if (ctx->p_conn->ssl_hostname) {
+                ap_log_cerror(APLOG_MARK, APLOG_TRACE1, status, ctx->owner, 
+                              "set SNI to %s for (%s)", 
+                              ctx->p_conn->ssl_hostname, 
+                              ctx->p_conn->hostname);
+                apr_table_setn(ctx->p_conn->connection->notes,
+                               "proxy-request-hostname", ctx->p_conn->ssl_hostname);
+            }
+            if (ctx->is_ssl) {
+                apr_table_setn(ctx->p_conn->connection->notes,
+                               "proxy-request-alpn-protos", "h2");
+            }
+        }
+    }
+
+run_session:
+    status = proxy_engine_run(ctx);
+    if (status == APR_SUCCESS) {
+        /* session and connection still ok */
+        if (next_request(ctx, 1) == APR_SUCCESS) {
+            /* more requests, run again */
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->owner, APLOGNO(03376)
+                          "run_session, again");
+            goto run_session;
+        }
+        /* done */
+        ctx->engine = NULL;
+    }
+
+reconnect:
+    if (next_request(ctx, 1) == APR_SUCCESS) {
+        /* Still more to do, tear down old conn and start over */
+        if (ctx->p_conn) {
+            ctx->p_conn->close = 1;
+            /*only in trunk so far */
+            /*proxy_run_detach_backend(r, ctx->p_conn);*/
+            ap_proxy_release_connection(ctx->proxy_func, ctx->p_conn, ctx->server);
+            ctx->p_conn = NULL;
+        }
+        ++reconnects;
+        if (reconnects < 5 && !ctx->owner->aborted) {
+            goto run_connect;
+        } 
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->owner, APLOGNO(10023)
+                      "giving up after %d reconnects, %d requests todo",
+                      reconnects, h2_proxy_fifo_count(ctx->requests));
+    }
+    
+cleanup:
+    if (ctx->p_conn) {
+        if (status != APR_SUCCESS) {
+            /* close socket when errors happened or session shut down (EOF) */
+            ctx->p_conn->close = 1;
+        }
+        /*only in trunk so far */
+        /*proxy_run_detach_backend(ctx->rbase, ctx->p_conn);*/
+        ap_proxy_release_connection(ctx->proxy_func, ctx->p_conn, ctx->server);
+        ctx->p_conn = NULL;
+    }
+
+    /* Any requests will still have need to fail */
+    while (APR_SUCCESS == h2_proxy_fifo_try_pull(ctx->requests, (void**)&r)) {
+        request_done(ctx, r, HTTP_SERVICE_UNAVAILABLE, 1);
+    }
+    
+    ap_set_module_config(ctx->owner->conn_config, &proxy_http2_module, NULL);
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, ctx->owner, 
+                  APLOGNO(03377) "leaving handler");
+    return ctx->r_status;
+}
+
+static void register_hook(apr_pool_t *p)
+{
+    ap_hook_post_config(h2_proxy_post_config, NULL, NULL, APR_HOOK_MIDDLE);
+
+    proxy_hook_scheme_handler(proxy_http2_handler, NULL, NULL, APR_HOOK_FIRST);
+    proxy_hook_canon_handler(proxy_http2_canon, NULL, NULL, APR_HOOK_FIRST);
+}
+