Merging upstream version 2.4.59.

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

1 files changed, 362 insertions, 0 deletions

diff --git a/modules/http2/h2_ws.c b/modules/http2/h2_ws.c
new file mode 100644
index 0000000..396e6e1
--- /dev/null
+++ b/modules/http2/h2_ws.c
@@ -0,0 +1,362 @@
+/* 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 <assert.h>
+
+#include "apr.h"
+#include "apr_strings.h"
+#include "apr_lib.h"
+#include "apr_sha1.h"
+#include "apr_strmatch.h"
+
+#include <ap_mmn.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_connection.h>
+#include <http_protocol.h>
+#include <http_request.h>
+#include <http_log.h>
+#include <http_ssl.h>
+#include <http_vhost.h>
+#include <util_filter.h>
+#include <ap_mpm.h>
+
+#include "h2_private.h"
+#include "h2_config.h"
+#include "h2_conn_ctx.h"
+#include "h2_headers.h"
+#include "h2_request.h"
+#include "h2_ws.h"
+
+#if H2_USE_WEBSOCKETS
+
+#include "apr_encode.h" /* H2_USE_WEBSOCKETS is conditional on APR 1.6+ */
+
+static ap_filter_rec_t *c2_ws_out_filter_handle;
+
+struct ws_filter_ctx {
+    const char *ws_accept_base64;
+    int has_final_response;
+    int override_body;
+};
+
+/**
+ * Generate the "Sec-WebSocket-Accept" header field for the given key
+ * (base64 encoded) as defined in RFC 6455 ch. 4.2.2 step 5.3
+ */
+static const char *gen_ws_accept(conn_rec *c, const char *key_base64)
+{
+    apr_byte_t dgst[APR_SHA1_DIGESTSIZE];
+    const char ws_guid[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+    apr_sha1_ctx_t sha1_ctx;
+
+    apr_sha1_init(&sha1_ctx);
+    apr_sha1_update(&sha1_ctx, key_base64, (unsigned int)strlen(key_base64));
+    apr_sha1_update(&sha1_ctx, ws_guid, (unsigned int)strlen(ws_guid));
+    apr_sha1_final(dgst, &sha1_ctx);
+
+    return apr_pencode_base64_binary(c->pool, dgst, sizeof(dgst),
+                                     APR_ENCODE_NONE, NULL);
+}
+
+const h2_request *h2_ws_rewrite_request(const h2_request *req,
+                                        conn_rec *c2, int no_body)
+{
+    h2_conn_ctx_t *conn_ctx = h2_conn_ctx_get(c2);
+    h2_request *wsreq;
+    unsigned char key_raw[16];
+    const char *key_base64, *accept_base64;
+    struct ws_filter_ctx *ws_ctx;
+    apr_status_t rv;
+
+    if (!conn_ctx || !req->protocol || strcmp("websocket", req->protocol))
+        return req;
+
+    if (ap_cstr_casecmp("CONNECT", req->method)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                      "h2_c2(%s-%d): websocket request with method %s",
+                      conn_ctx->id, conn_ctx->stream_id, req->method);
+        return req;
+    }
+    if (!req->scheme) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                      "h2_c2(%s-%d): websocket CONNECT without :scheme",
+                      conn_ctx->id, conn_ctx->stream_id);
+        return req;
+    }
+    if (!req->path) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                      "h2_c2(%s-%d): websocket CONNECT without :path",
+                      conn_ctx->id, conn_ctx->stream_id);
+        return req;
+    }
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                  "h2_c2(%s-%d): websocket CONNECT for %s",
+                  conn_ctx->id, conn_ctx->stream_id, req->path);
+    /* Transform the HTTP/2 extended CONNECT to an internal GET using
+     * the HTTP/1.1 version of websocket connection setup. */
+    wsreq = h2_request_clone(c2->pool, req);
+    wsreq->method = "GET";
+    wsreq->protocol = NULL;
+    apr_table_set(wsreq->headers, "Upgrade", "websocket");
+    apr_table_add(wsreq->headers, "Connection", "Upgrade");
+    /* add Sec-WebSocket-Key header */
+    rv = apr_generate_random_bytes(key_raw, sizeof(key_raw));
+    if (rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(10461)
+                     "error generating secret");
+        return NULL;
+    }
+    key_base64 = apr_pencode_base64_binary(c2->pool, key_raw, sizeof(key_raw),
+                                           APR_ENCODE_NONE, NULL);
+    apr_table_set(wsreq->headers, "Sec-WebSocket-Key", key_base64);
+    /* This is now the request to process internally */
+
+    /* When this request gets processed and delivers a 101 response,
+     * we expect it to carry a "Sec-WebSocket-Accept" header with
+     * exactly the following value, as per RFC 6455. */
+    accept_base64 = gen_ws_accept(c2, key_base64);
+    /* Add an output filter that intercepts generated responses:
+     * - if a valid WebSocket negotiation happens, transform the
+     *   101 response to a 200
+     * - if a 2xx response happens, that does not pass the Accept test,
+     *   return a 502 indicating that the URI seems not support the websocket
+     *   protocol (RFC 8441 does not define this, but it seems the best
+     *   choice)
+     * - if a 3xx, 4xx or 5xx response happens, forward this unchanged.
+     */
+    ws_ctx = apr_pcalloc(c2->pool, sizeof(*ws_ctx));
+    ws_ctx->ws_accept_base64 = accept_base64;
+    /* insert our filter just before the C2 core filter */
+    ap_remove_output_filter_byhandle(c2->output_filters, "H2_C2_NET_OUT");
+    ap_add_output_filter("H2_C2_WS_OUT", ws_ctx, NULL, c2);
+    ap_add_output_filter("H2_C2_NET_OUT", NULL, NULL, c2);
+    /* Mark the connection as being an Upgrade, with some special handling
+     * since the request needs an EOS, without the stream being closed  */
+    conn_ctx->is_upgrade = 1;
+
+    return wsreq;
+}
+
+static apr_bucket *make_valid_resp(conn_rec *c2, int status,
+                                   apr_table_t *headers, apr_table_t *notes)
+{
+    apr_table_t *nheaders, *nnotes;
+
+    ap_assert(headers);
+    nheaders = apr_table_clone(c2->pool, headers);
+    apr_table_unset(nheaders, "Connection");
+    apr_table_unset(nheaders, "Upgrade");
+    apr_table_unset(nheaders, "Sec-WebSocket-Accept");
+    nnotes = notes? apr_table_clone(c2->pool, notes) :
+                    apr_table_make(c2->pool, 10);
+#if AP_HAS_RESPONSE_BUCKETS
+    return ap_bucket_response_create(status, NULL, nheaders, nnotes,
+                                     c2->pool, c2->bucket_alloc);
+#else
+    return h2_bucket_headers_create(c2->bucket_alloc,
+                                    h2_headers_create(status, nheaders,
+                                                      nnotes, 0, c2->pool));
+#endif
+}
+
+static apr_bucket *make_invalid_resp(conn_rec *c2, int status,
+                                     apr_table_t *notes)
+{
+    apr_table_t *nheaders, *nnotes;
+
+    nheaders = apr_table_make(c2->pool, 10);
+    apr_table_setn(nheaders, "Content-Length", "0");
+    nnotes = notes? apr_table_clone(c2->pool, notes) :
+                    apr_table_make(c2->pool, 10);
+#if AP_HAS_RESPONSE_BUCKETS
+    return ap_bucket_response_create(status, NULL, nheaders, nnotes,
+                                     c2->pool, c2->bucket_alloc);
+#else
+    return h2_bucket_headers_create(c2->bucket_alloc,
+                                    h2_headers_create(status, nheaders,
+                                                      nnotes, 0, c2->pool));
+#endif
+}
+
+static void ws_handle_resp(conn_rec *c2, h2_conn_ctx_t *conn_ctx,
+                           struct ws_filter_ctx *ws_ctx, apr_bucket *b)
+{
+#if AP_HAS_RESPONSE_BUCKETS
+    ap_bucket_response *resp = b->data;
+#else /* AP_HAS_RESPONSE_BUCKETS */
+    h2_headers *resp = h2_bucket_headers_get(b);
+#endif /* !AP_HAS_RESPONSE_BUCKETS */
+    apr_bucket *b_override = NULL;
+    int is_final = 0;
+    int override_body = 0;
+
+    if (ws_ctx->has_final_response) {
+        /* already did, nop */
+        return;
+    }
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c2,
+                  "h2_c2(%s-%d): H2_C2_WS_OUT inspecting response %d",
+                  conn_ctx->id, conn_ctx->stream_id, resp->status);
+    if (resp->status == HTTP_SWITCHING_PROTOCOLS) {
+        /* The resource agreed to switch protocol. But this is only valid
+         * if it send back the correct Sec-WebSocket-Accept header value */
+        const char *hd = apr_table_get(resp->headers, "Sec-WebSocket-Accept");
+        if (hd && !strcmp(ws_ctx->ws_accept_base64, hd)) {
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                          "h2_c2(%s-%d): websocket CONNECT, valid 101 Upgrade"
+                          ", converting to 200 response",
+                          conn_ctx->id, conn_ctx->stream_id);
+            b_override = make_valid_resp(c2, HTTP_OK, resp->headers, resp->notes);
+            is_final = 1;
+        }
+        else {
+            if (!hd) {
+                /* This points to someone being confused */
+                ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, c2, APLOGNO(10462)
+                              "h2_c2(%s-%d): websocket CONNECT, got 101 response "
+                              "without Sec-WebSocket-Accept header",
+                              conn_ctx->id, conn_ctx->stream_id);
+            }
+            else {
+                /* This points to a bug, either in our WebSockets negotiation
+                 * or in the request processings implementation of WebSockets */
+                ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c2, APLOGNO(10463)
+                              "h2_c2(%s-%d): websocket CONNECT, 101 response "
+                              "with 'Sec-WebSocket-Accept: %s' but expected %s",
+                              conn_ctx->id, conn_ctx->stream_id, hd,
+                              ws_ctx->ws_accept_base64);
+            }
+            b_override = make_invalid_resp(c2, HTTP_BAD_GATEWAY, resp->notes);
+            override_body = is_final = 1;
+        }
+    }
+    else if (resp->status < 200) {
+        /* other intermediate response, pass through */
+    }
+    else if (resp->status < 300) {
+        /* Failure, we might be talking to a plain http resource */
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
+                      "h2_c2(%s-%d): websocket CONNECT, invalid response %d",
+                      conn_ctx->id, conn_ctx->stream_id, resp->status);
+        b_override = make_invalid_resp(c2, HTTP_BAD_GATEWAY, resp->notes);
+        override_body = is_final = 1;
+    }
+    else {
+        /* error response, pass through. */
+        ws_ctx->has_final_response = 1;
+    }
+
+    if (b_override) {
+        APR_BUCKET_INSERT_BEFORE(b, b_override);
+        apr_bucket_delete(b);
+        b = b_override;
+    }
+    if (override_body) {
+        APR_BUCKET_INSERT_AFTER(b, apr_bucket_eos_create(c2->bucket_alloc));
+        ws_ctx->override_body = 1;
+    }
+    if (is_final) {
+        ws_ctx->has_final_response = 1;
+        conn_ctx->has_final_response = 1;
+    }
+}
+
+static apr_status_t h2_c2_ws_filter_out(ap_filter_t* f, apr_bucket_brigade* bb)
+{
+    struct ws_filter_ctx *ws_ctx = f->ctx;
+    h2_conn_ctx_t *conn_ctx = h2_conn_ctx_get(f->c);
+    apr_bucket *b, *bnext;
+
+    ap_assert(conn_ctx);
+    if (ws_ctx->override_body) {
+        /* We have overridden the original response and also its body.
+         * If this filter is called again, we signal a hard abort to
+         * allow processing to terminate at the earliest. */
+        f->c->aborted = 1;
+        return APR_ECONNABORTED;
+    }
+
+    /* Inspect the brigade, looking for RESPONSE/HEADER buckets.
+     * Remember, this filter is only active for client websocket CONNECT
+     * requests that we translated to an internal GET with websocket
+     * headers.
+     * We inspect the repsone to see if the internal resource actually
+     * agrees to talk websocket or is "just" a normal HTTP resource that
+     * ignored the websocket request headers. */
+    for (b = APR_BRIGADE_FIRST(bb);
+         b != APR_BRIGADE_SENTINEL(bb);
+         b = bnext)
+    {
+        bnext = APR_BUCKET_NEXT(b);
+        if (APR_BUCKET_IS_METADATA(b)) {
+#if AP_HAS_RESPONSE_BUCKETS
+            if (AP_BUCKET_IS_RESPONSE(b)) {
+#else
+            if (H2_BUCKET_IS_HEADERS(b)) {
+#endif /* !AP_HAS_RESPONSE_BUCKETS */
+                ws_handle_resp(f->c, conn_ctx, ws_ctx, b);
+                continue;
+            }
+        }
+        else if (ws_ctx->override_body) {
+            apr_bucket_delete(b);
+        }
+    }
+    return ap_pass_brigade(f->next, bb);
+}
+
+static int ws_post_read(request_rec *r)
+{
+
+    if (r->connection->master) {
+        h2_conn_ctx_t *conn_ctx = h2_conn_ctx_get(r->connection);
+        if (conn_ctx && conn_ctx->is_upgrade &&
+            !h2_config_sgeti(r->server, H2_CONF_WEBSOCKETS)) {
+            return HTTP_NOT_IMPLEMENTED;
+        }
+    }
+    return DECLINED;
+}
+
+void h2_ws_register_hooks(void)
+{
+    ap_hook_post_read_request(ws_post_read, NULL, NULL, APR_HOOK_MIDDLE);
+    c2_ws_out_filter_handle =
+        ap_register_output_filter("H2_C2_WS_OUT", h2_c2_ws_filter_out,
+                                  NULL, AP_FTYPE_NETWORK);
+}
+
+#else /* H2_USE_WEBSOCKETS */
+
+const h2_request *h2_ws_rewrite_request(const h2_request *req,
+                                        conn_rec *c2, int no_body)
+{
+    (void)c2;
+    (void)no_body;
+    /* no rewriting */
+    return req;
+}
+
+void h2_ws_register_hooks(void)
+{
+    /*  NOP */
+}
+
+#endif /* H2_USE_WEBSOCKETS (else part) */