ssltunnel.c revision 253895 
1/* Copyright 2011 Justin Erenkrantz and Greg Stein
2 *
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16/*** Setup a SSL tunnel over a HTTP proxy, according to RFC 2817. ***/
17
18#include <apr_pools.h>
19#include <apr_strings.h>
20
21#include "serf.h"
22#include "serf_private.h"
23
24
25/* Structure passed around as baton for the CONNECT request and respone. */
26typedef struct {
27    apr_pool_t *pool;
28    const char *uri;
29} req_ctx_t;
30
31/* forward declaration. */
32static apr_status_t setup_request(serf_request_t *request,
33                                  void *setup_baton,
34                                  serf_bucket_t **req_bkt,
35                                  serf_response_acceptor_t *acceptor,
36                                  void **acceptor_baton,
37                                  serf_response_handler_t *handler,
38                                  void **handler_baton,
39                                  apr_pool_t *pool);
40
41static serf_bucket_t* accept_response(serf_request_t *request,
42                                      serf_bucket_t *stream,
43                                      void *acceptor_baton,
44                                      apr_pool_t *pool)
45{
46    serf_bucket_t *c;
47    serf_bucket_alloc_t *bkt_alloc;
48#if 0
49    req_ctx_t *ctx = acceptor_baton;
50#endif
51
52    /* get the per-request bucket allocator */
53    bkt_alloc = serf_request_get_alloc(request);
54
55    /* Create a barrier so the response doesn't eat us! */
56    c = serf_bucket_barrier_create(stream, bkt_alloc);
57
58    return serf_bucket_response_create(c, bkt_alloc);
59}
60
61/* If a 200 OK was received for the CONNECT request, consider the connection
62   as ready for use. */
63static apr_status_t handle_response(serf_request_t *request,
64                                    serf_bucket_t *response,
65                                    void *handler_baton,
66                                    apr_pool_t *pool)
67{
68    apr_status_t status;
69    serf_status_line sl;
70    req_ctx_t *ctx = handler_baton;
71
72    if (! response) {
73        serf_connection_request_create(request->conn,
74                                       setup_request,
75                                       ctx);
76        return APR_SUCCESS;
77    }
78
79    status = serf_bucket_response_status(response, &sl);
80    if (SERF_BUCKET_READ_ERROR(status)) {
81        return status;
82    }
83    if (!sl.version && (APR_STATUS_IS_EOF(status) ||
84                      APR_STATUS_IS_EAGAIN(status)))
85    {
86        return status;
87    }
88
89    status = serf_bucket_response_wait_for_headers(response);
90    if (status && !APR_STATUS_IS_EOF(status)) {
91        return status;
92    }
93
94    /* RFC 2817:  Any successful (2xx) response to a CONNECT request indicates
95       that the proxy has established a connection to the requested host and
96       port, and has switched to tunneling the current connection to that server
97       connection.
98    */
99    if (sl.code >= 200 && sl.code < 300) {
100        request->conn->state = SERF_CONN_CONNECTED;
101
102        /* Body is supposed to be empty. */
103        apr_pool_destroy(ctx->pool);
104        serf_bucket_destroy(request->conn->ssltunnel_ostream);
105        request->conn->stream = NULL;
106        ctx = NULL;
107
108        serf__log(CONN_VERBOSE, __FILE__,
109                  "successfully set up ssl tunnel on connection 0x%x\n",
110                  request->conn);
111
112        return APR_EOF;
113    }
114
115    /* Authentication failure and 2xx Ok are handled at this point,
116       the rest are errors. */
117    return SERF_ERROR_SSLTUNNEL_SETUP_FAILED;
118}
119
120/* Prepare the CONNECT request. */
121static apr_status_t setup_request(serf_request_t *request,
122                                  void *setup_baton,
123                                  serf_bucket_t **req_bkt,
124                                  serf_response_acceptor_t *acceptor,
125                                  void **acceptor_baton,
126                                  serf_response_handler_t *handler,
127                                  void **handler_baton,
128                                  apr_pool_t *pool)
129{
130    req_ctx_t *ctx = setup_baton;
131
132    *req_bkt =
133        serf_request_bucket_request_create(request,
134                                           "CONNECT", ctx->uri,
135                                           NULL,
136                                           serf_request_get_alloc(request));
137    *acceptor = accept_response;
138    *acceptor_baton = ctx;
139    *handler = handle_response;
140    *handler_baton = ctx;
141
142    return APR_SUCCESS;
143}
144
145static apr_status_t detect_eof(void *baton, serf_bucket_t *aggregate_bucket)
146{
147    serf_connection_t *conn = baton;
148    conn->hit_eof = 1;
149    return APR_EAGAIN;
150}
151
152/* SSL tunnel is needed, push a CONNECT request on the connection. */
153apr_status_t serf__ssltunnel_connect(serf_connection_t *conn)
154{
155    req_ctx_t *ctx;
156    apr_pool_t *ssltunnel_pool;
157
158    apr_pool_create(&ssltunnel_pool, conn->pool);
159
160    ctx = apr_palloc(ssltunnel_pool, sizeof(*ctx));
161    ctx->pool = ssltunnel_pool;
162    ctx->uri = apr_psprintf(ctx->pool, "%s:%d", conn->host_info.hostname,
163                            conn->host_info.port);
164
165    conn->ssltunnel_ostream = serf__bucket_stream_create(conn->allocator,
166                                                         detect_eof,
167                                                         conn);
168
169    serf__ssltunnel_request_create(conn,
170                                   setup_request,
171                                   ctx);
172
173    conn->state = SERF_CONN_SETUP_SSLTUNNEL;
174    serf__log(CONN_VERBOSE, __FILE__,
175              "setting up ssl tunnel on connection 0x%x\n", conn);
176
177    return APR_SUCCESS;
178}
179