2 * Copyright 2016 IoT.bzh
3 * Author: José Bollo <jose.bollo@iot.bzh>
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
26 #include <sys/types.h>
27 #include <sys/socket.h>
32 /**************** WebSocket handshake ****************************/
34 static const char *compkeys[32] = {
35 "lYKr2sn9+ILcLpkqdrE2VQ==", "G5J7ncQnmS/MubIYcqKWM+E6k8I=",
36 "gjN6eOU/6Yy7dBTJ+EaQSw==", "P5QzN7mRt4DeRWxKdG7s4/NCEwk=",
37 "ziLin6OQ0/a1+cGaI9Mupg==", "yvpxcFJAGam6huL77vz34CdShyU=",
38 "KMfd2bHKah0U5mk2Kg/LIg==", "lyYxfDP5YunhkBF+nAWb/w6K4yg=",
39 "fQ/ISF1mNCPRMyAj3ucqNg==", "91YY1EUelb4eMU24Z8WHhJ9cHmc=",
40 "RHlfiVVE1lM1AJnErI8dFg==", "UdZQc0JaihQJV5ETCZ84Av88pxQ=",
41 "NVy3L2ujXN7v3KEJwK92ww==", "+dE7iITxhExjBtf06VYNWChHqx8=",
42 "cCNAgttlgELfbDDIfhujww==", "W2JiswqbTAXx5u84EtjbtqAW2Bg=",
43 "K+oQvEDWJP+WXzRS5BJDFw==", "szgW10a9AuD+HtfS4ylaqWfzWAs=",
44 "nmg43S4DpVaxye+oQv9KTw==", "8XK74jB9xFfTzzl0wTqW04k3tPE=",
45 "LIqZ23sEppbF4YJR9LQ4/w==", "f8lJBQEbR8QmmvPHZpA0smlIeeA=",
46 "WY1vvvY2j/3V9DAGW3ZZcA==", "lROlE4vL4cjU1Vnk6rISc9gVKN0=",
47 "Ia+dgHnA9QaBrbxuqh4wgQ==", "GiGjxFdSaF0EGTl2cjvFsVmJnfM=",
48 "MfpIVG082jFTV7SxTNNijQ==", "f5I2h53hBsT5ES3EHhnxAJ2nqsw=",
49 "kFumnAw5d/WctG0yAUHPiQ==", "aQQmOjoABl7mrbliTPS1bOkndOs=",
50 "MHiEc+Qc8w/SJ3zMHEM8pA==", "FVCxLBmoil3gY0jSX3aNJ6kR/t4="
53 static const char websocket_s[] = "websocket";
54 static const char sec_websocket_key_s[] = "Sec-WebSocket-Key";
55 static const char sec_websocket_version_s[] = "Sec-WebSocket-Version";
56 static const char sec_websocket_accept_s[] = "Sec-WebSocket-Accept";
57 static const char sec_websocket_protocol_s[] = "Sec-WebSocket-Protocol";
59 static const char vseparators[] = " \t,";
61 /* get randomly a pair of key/accept value */
62 static void getkeypair(const char **key, const char **ack)
67 r = (r & 15) + (r >> 4);
73 /* joins the strings using the separator */
74 static char *strjoin(int count, const char **strings, const char *separ)
80 /* creates the count if needed */
82 for(count = 0 ; strings[count] != NULL ; count++);
84 /* compute the length of the result */
89 /* allocates the result */
90 result = malloc(length + 1);
94 /* create the result */
96 iter = stpcpy(result, strings[idx = 0]);
98 iter = stpcpy(stpcpy(iter, separ), strings[idx]);
99 // assert(iter - result == length);
106 /* creates the http message for the request */
107 static int make_request(char **request, const char *path, const char *key, const char *protocols)
109 int rc = asprintf(request,
111 "Upgrade: websocket\r\n"
112 "Connection: Upgrade\r\n"
113 "Sec-WebSocket-Version: 13\r\n"
114 "Sec-WebSocket-Key: %s\r\n"
115 "Sec-WebSocket-Protocol: %s\r\n"
116 "Content-Length: 0\r\n"
130 /* create the request and send it to fd, returns the expected accept string */
131 static const char *send_request(int fd, const char **protocols, const char *path)
133 const char *key, *ack;
134 char *protolist, *request;
137 /* make the list of accepted protocols */
138 protolist = strjoin(-1, protocols, ", ");
139 if (protolist == NULL)
142 /* create the request */
143 getkeypair(&key, &ack);
144 length = make_request(&request, path, key, protolist);
149 /* send the request */
150 do { rc = (int)write(fd, request, length); } while(rc < 0 && errno == EINTR);
152 return rc < 0 ? NULL : ack;
155 /* read a line not efficiently but without buffering */
156 static int receive_line(int fd, char *line, int size)
158 int rc, length = 0, cr = 0;
160 if (length >= size) {
164 do { rc = (int)read(fd, line + length, 1); } while (rc < 0 && errno == EINTR);
167 if (line[length] == '\r')
169 else if (cr != 0 && line[length] == '\n') {
179 static inline int isheader(const char *head, size_t klen, const char *key)
181 return strncasecmp(head, key, klen) == 0 && key[klen] == 0;
184 /* receives and scan the response */
185 static int receive_response(int fd, const char **protocols, const char *ack)
187 char line[4096], *it;
188 int rc, haserr, result = -1;
191 /* check the header line to be something like: "HTTP/1.1 101 Switching Protocols" */
192 rc = receive_line(fd, line, (int)sizeof(line));
195 len = strcspn(line, " ");
196 if (len != 8 || 0 != strncmp(line, "HTTP/1.1", 8))
199 len = strspn(line, " ");
203 len = strcspn(line, " ");
204 if (len != 3 || 0 != strncmp(line, "101", 3))
207 /* reads the rest of the response until empty line */
211 rc = receive_line(fd, line, (int)sizeof(line));
216 len = strcspn(line, ": ");
217 if (len != 0 && line[len] == ':') {
218 /* checks the headers values */
220 it += strspn(it, " ,");
221 it[strcspn(it, " ,")] = 0;
222 if (isheader(line, len, "Sec-WebSocket-Accept")) {
223 if (strcmp(it, ack) != 0)
225 } else if (isheader(line, len, "Sec-WebSocket-Protocol")) {
227 while(protocols[result] != NULL && strcmp(it, protocols[result]) != 0)
229 } else if (isheader(line, len, "Upgrade")) {
230 if (strcmp(it, "websocket") != 0)
232 } else if (isheader(line, len, "Content-Length")) {
238 /* skips the remaining of the message */
239 while (clen >= sizeof line) {
240 while (read(fd, line, sizeof line) < 0 && errno == EINTR);
244 while (read(fd, line, len) < 0 && errno == EINTR);
248 else if (result < 0) {
250 while(protocols[result] != NULL)
257 static int negociate(int fd, const char **protocols, const char *path)
259 const char *ack = send_request(fd, protocols, path);
260 return ack == NULL ? -1 : receive_response(fd, protocols, ack);
263 /* tiny parse a "standard" websock uri ws://host:port/path... */
264 static int parse_uri(const char *uri, char **host, char **service, const char **path)
270 if (strncmp(uri, "ws://", 5) == 0)
275 hlen = strcspn(h, ":/");
280 /* the port (optional) */
283 plen = strcspn(p, "/");
296 /* make the result */
297 *host = strndup(h, hlen);
300 *service = plen ? strndup(h, hlen) : strdup("http");
301 if (*service != NULL) {
319 static const char *proto_json1[2] = { "x-afb-ws-json1", NULL };
321 struct afb_wsj1 *afb_ws_client_connect_wsj1(const char *uri, struct afb_wsj1_itf *itf, void *closure)
324 char *host, *service;
326 struct addrinfo hint, *rai, *iai;
327 struct afb_wsj1 *result;
330 rc = parse_uri(uri, &host, &service, &path);
335 memset(&hint, 0, sizeof hint);
336 hint.ai_family = AF_INET;
337 hint.ai_socktype = SOCK_STREAM;
338 rc = getaddrinfo(host, service, &hint, &rai);
349 while (iai != NULL) {
350 fd = socket(iai->ai_family, iai->ai_socktype, iai->ai_protocol);
352 rc = connect(fd, iai->ai_addr, iai->ai_addrlen);
354 rc = negociate(fd, proto_json1, path);
356 result = afb_wsj1_create(fd, itf, closure);
370 /* compute the queried path */
371 static char *makequery(const char *path, const char *uuid, const char *token)
380 rc = asprintf(&result, "/%s", path);
382 rc = asprintf(&result, "/%s?x-afb-token=%s", path, token);
385 rc = asprintf(&result, "/%s?x-afb-uuid=%s", path, uuid);
387 rc = asprintf(&result, "/%s?x-afb-uuid=%s&x-afb-token=%s", path, uuid, token);