summaryrefslogtreecommitdiffstats
path: root/web/server/h2o/libh2o/lib/websocket.c
blob: 2886acda631d5b30ddc5b3cf08eac7926baf3d7d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/*
 * Copyright (c) 2014 DeNA Co., Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <openssl/sha.h>
#include "h2o/websocket.h"

#define WS_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

static void create_accept_key(char *dst, const char *client_key)
{
    uint8_t sha1buf[20], key_src[60];

    memcpy(key_src, client_key, 24);
    memcpy(key_src + 24, WS_GUID, 36);
    SHA1(key_src, sizeof(key_src), sha1buf);
    h2o_base64_encode(dst, sha1buf, sizeof(sha1buf), 0);
    dst[28] = '\0';
}

static void on_close(h2o_websocket_conn_t *conn)
{
    (*conn->cb)(conn, NULL);
}

static void on_recv(h2o_socket_t *sock, const char *err)
{
    h2o_websocket_conn_t *conn = sock->data;

    if (err != NULL) {
        on_close(conn);
        return;
    }
    h2o_websocket_proceed(conn);
}

static void on_write_complete(h2o_socket_t *sock, const char *err)
{
    h2o_websocket_conn_t *conn = sock->data;

    if (err != NULL) {
        on_close(conn);
        return;
    }
    h2o_websocket_proceed(conn);
}

static ssize_t recv_callback(wslay_event_context_ptr ctx, uint8_t *buf, size_t len, int flags, void *_conn)
{
    h2o_websocket_conn_t *conn = _conn;

    /* return WOULDBLOCK if no data */
    if (conn->sock->input->size == 0) {
        wslay_event_set_error(conn->ws_ctx, WSLAY_ERR_WOULDBLOCK);
        return -1;
    }

    if (conn->sock->input->size < len)
        len = conn->sock->input->size;
    memcpy(buf, conn->sock->input->bytes, len);
    h2o_buffer_consume(&conn->sock->input, len);
    return len;
}

static ssize_t send_callback(wslay_event_context_ptr ctx, const uint8_t *data, size_t len, int flags, void *_conn)
{
    h2o_websocket_conn_t *conn = _conn;
    h2o_iovec_t buf;

    /* return WOULDBLOCK if pending (TODO: queue fixed number of chunks, instead of only one) */
    if (h2o_socket_is_writing(conn->sock)) {
        wslay_event_set_error(conn->ws_ctx, WSLAY_ERR_WOULDBLOCK);
        return -1;
    }

    /* copy data */
    conn->_write_buf = h2o_mem_realloc(conn->_write_buf, len);
    memcpy(conn->_write_buf, data, len);

    /* write */
    buf.base = conn->_write_buf;
    buf.len = len;
    h2o_socket_write(conn->sock, &buf, 1, on_write_complete);

    return len;
}

static void on_msg_callback(wslay_event_context_ptr ctx, const struct wslay_event_on_msg_recv_arg *arg, void *_conn)
{
    h2o_websocket_conn_t *conn = _conn;
    (*conn->cb)(conn, arg);
}

static void on_complete(void *user_data, h2o_socket_t *sock, size_t reqsize)
{
    h2o_websocket_conn_t *conn = user_data;

    /* close the connection on error */
    if (sock == NULL) {
        (*conn->cb)(conn, NULL);
        return;
    }

    conn->sock = sock;
    sock->data = conn;
    h2o_buffer_consume(&sock->input, reqsize);
    h2o_websocket_proceed(conn);
}

h2o_websocket_conn_t *h2o_upgrade_to_websocket(h2o_req_t *req, const char *client_key, void *data, h2o_websocket_msg_callback cb)
{
    h2o_websocket_conn_t *conn = h2o_mem_alloc(sizeof(*conn));
    char accept_key[29];

    /* only for http1 connection */
    assert(req->version < 0x200);

    /* setup the context */
    memset(conn, 0, sizeof(*conn));
    // conn->sock = sock; set by on_complete
    conn->ws_callbacks.recv_callback = recv_callback;
    conn->ws_callbacks.send_callback = send_callback;
    conn->ws_callbacks.on_msg_recv_callback = on_msg_callback;
    conn->data = data;
    conn->cb = cb;

    wslay_event_context_server_init(&conn->ws_ctx, &conn->ws_callbacks, conn);

    /* build response */
    create_accept_key(accept_key, client_key);
    req->res.status = 101;
    req->res.reason = "Switching Protocols";
    h2o_add_header(&req->pool, &req->res.headers, H2O_TOKEN_UPGRADE, NULL, H2O_STRLIT("websocket"));
    h2o_add_header_by_str(&req->pool, &req->res.headers, H2O_STRLIT("sec-websocket-accept"), 0, NULL, accept_key,
                          strlen(accept_key));

    /* send */
    h2o_http1_upgrade(req, NULL, 0, on_complete, conn);

    return conn;
}

int h2o_is_websocket_handshake(h2o_req_t *req, const char **ws_client_key)
{
    ssize_t key_header_index;

    *ws_client_key = NULL;

    /* method */
    if (h2o_memis(req->input.method.base, req->input.method.len, H2O_STRLIT("GET"))) {
        /* ok */
    } else {
        return 0;
    }

    /* upgrade header */
    if (req->upgrade.base != NULL && h2o_lcstris(req->upgrade.base, req->upgrade.len, H2O_STRLIT("websocket"))) {
        /* ok */
    } else {
        return 0;
    }
    /* sec-websocket-key header */
    if ((key_header_index = h2o_find_header_by_str(&req->headers, H2O_STRLIT("sec-websocket-key"), -1)) != -1) {
        if (req->headers.entries[key_header_index].value.len != 24) {
            return -1;
        }
    } else {
        return 0;
    }

    *ws_client_key = req->headers.entries[key_header_index].value.base;
    return 0;
}

void h2o_websocket_close(h2o_websocket_conn_t *conn)
{
    if (conn->sock != NULL)
        h2o_socket_close(conn->sock);
    free(conn->_write_buf);
    wslay_event_context_free(conn->ws_ctx);
    free(conn);
}

void h2o_websocket_proceed(h2o_websocket_conn_t *conn)
{
    int handled;

    /* run the loop until getting to a point where no more progress can be achieved */
    do {
        handled = 0;
        if (!h2o_socket_is_writing(conn->sock) && wslay_event_want_write(conn->ws_ctx)) {
            if (wslay_event_send(conn->ws_ctx) != 0) {
                goto Close;
            }
            handled = 1;
        }
        if (conn->sock->input->size != 0 && wslay_event_want_read(conn->ws_ctx)) {
            if (wslay_event_recv(conn->ws_ctx) != 0) {
                goto Close;
            }
            handled = 1;
        }
    } while (handled);

    if (wslay_event_want_read(conn->ws_ctx)) {
        h2o_socket_read_start(conn->sock, on_recv);
    } else if (h2o_socket_is_writing(conn->sock) || wslay_event_want_write(conn->ws_ctx)) {
        h2o_socket_read_stop(conn->sock);
    } else {
        /* nothing is going on... close the socket */
        goto Close;
    }

    return;

Close:
    on_close(conn);
}