1 /*
2 * lws-minimal-raw-adopt-tcp
3 *
4 * Written in 2010-2019 by Andy Green <andy@warmcat.com>
5 *
6 * This file is made available under the Creative Commons CC0 1.0
7 * Universal Public Domain Dedication.
8 *
9 * This demonstrates integrating somebody else's connected tcp
10 * socket into the lws event loop as a RAW wsi. It's interesting in
11 * the kind of situation where you already have a connected socket
12 * in your application, and you need to hand it over to lws to deal with.
13 *
14 * Lws supports "adopting" these foreign sockets.
15 *
16 * If you simply want a connected client raw socket using lws alone, you
17 * can just use lws_client_connect_via_info() with info.method = "RAW".
18 *
19 */
20
21 #include <libwebsockets.h>
22 #include <string.h>
23 #include <signal.h>
24 #if !defined(WIN32)
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <netdb.h>
28 #include <arpa/inet.h>
29 #endif
30 #include <sys/types.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <stdlib.h>
34 #include <unistd.h>
35 #include <errno.h>
36
37 static int
callback_raw_test(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)38 callback_raw_test(struct lws *wsi, enum lws_callback_reasons reason,
39 void *user, void *in, size_t len)
40 {
41
42 switch (reason) {
43
44 /* callbacks related to raw socket descriptor */
45
46 case LWS_CALLBACK_RAW_ADOPT:
47 lwsl_user("LWS_CALLBACK_RAW_ADOPT\n");
48 lws_callback_on_writable(wsi);
49 break;
50
51 case LWS_CALLBACK_RAW_CLOSE:
52 lwsl_user("LWS_CALLBACK_RAW_CLOSE\n");
53 break;
54
55 case LWS_CALLBACK_RAW_RX:
56 lwsl_user("LWS_CALLBACK_RAW_RX (%d)\n", (int)len);
57 lwsl_hexdump_level(LLL_NOTICE, in, len);
58 break;
59
60 case LWS_CALLBACK_RAW_WRITEABLE:
61 if (lws_write(wsi,
62 (uint8_t *)"GET / HTTP/1.1\xd\xa\xd\xa", 18,
63 LWS_WRITE_RAW) != 18) {
64 lwsl_notice("%s: raw write failed\n", __func__);
65 return 1;
66 }
67 break;
68
69 default:
70 break;
71 }
72
73 return 0;
74 }
75
76 static struct lws_protocols protocols[] = {
77 { "raw-test", callback_raw_test, 0, 0 },
78 { NULL, NULL, 0, 0 } /* terminator */
79 };
80
81 static int interrupted;
82
sigint_handler(int sig)83 void sigint_handler(int sig)
84 {
85 interrupted = 1;
86 }
87
main(int argc,const char ** argv)88 int main(int argc, const char **argv)
89 {
90 struct lws_context_creation_info info;
91 struct lws_context *context;
92 lws_sock_file_fd_type sock;
93 struct addrinfo h, *r, *rp;
94 struct lws_vhost *vhost;
95 const char *p;
96 int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
97 /* for LLL_ verbosity above NOTICE to be built into lws,
98 * lws must have been configured and built with
99 * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
100 /* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */
101 /* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */
102 /* | LLL_DEBUG */;
103
104 signal(SIGINT, sigint_handler);
105
106 if ((p = lws_cmdline_option(argc, argv, "-d")))
107 logs = atoi(p);
108
109 lws_set_log_level(logs, NULL);
110 lwsl_user("LWS minimal raw adopt tcp\n");
111
112 memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
113 info.options = LWS_SERVER_OPTION_EXPLICIT_VHOSTS;
114
115 context = lws_create_context(&info);
116 if (!context) {
117 lwsl_err("lws init failed\n");
118 return 1;
119 }
120
121 info.port = CONTEXT_PORT_NO_LISTEN_SERVER;
122 info.protocols = protocols;
123
124 vhost = lws_create_vhost(context, &info);
125 if (!vhost) {
126 lwsl_err("lws vhost creation failed\n");
127 goto bail;
128 }
129
130 /*
131 * Connect our own "foreign" socket to libwebsockets.org:80
132 *
133 * Normally you would do this with lws_client_connect_via_info() inside
134 * the lws event loop, hiding all this detail. But this example
135 * demonstrates how to integrate an externally-connected "foreign"
136 * socket, so we create one by hand.
137 */
138
139 memset(&h, 0, sizeof(h));
140 h.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
141 h.ai_socktype = SOCK_STREAM;
142 h.ai_protocol = IPPROTO_TCP;
143
144 n = getaddrinfo("libwebsockets.org", "80", &h, &r);
145 if (n) {
146 lwsl_err("%s: problem resolving libwebsockets.org: %s\n", __func__, gai_strerror(n));
147 return 1;
148 }
149
150 for (rp = r; rp; rp = rp->ai_next) {
151 sock.sockfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
152 if (sock.sockfd != LWS_SOCK_INVALID)
153 break;
154 }
155 if (!rp) {
156 lwsl_err("%s: unable to create INET socket\n", __func__);
157 freeaddrinfo(r);
158
159 return 1;
160 }
161
162 lwsl_user("Starting connect...\n");
163 if (connect(sock.sockfd, rp->ai_addr, sizeof(*rp->ai_addr)) < 0) {
164 lwsl_err("%s: unable to connect to libwebsockets.org:80\n", __func__);
165 freeaddrinfo(r);
166 return 1;
167 }
168
169 freeaddrinfo(r);
170 signal(SIGINT, sigint_handler);
171 lwsl_user("Connected...\n");
172
173 /* our foreign socket is connected... adopt it into lws */
174
175 if (!lws_adopt_descriptor_vhost(vhost, LWS_ADOPT_SOCKET, sock,
176 protocols[0].name, NULL)) {
177 lwsl_err("%s: foreign socket adoption failed\n", __func__);
178 goto bail;
179 }
180
181 while (n >= 0 && !interrupted)
182 n = lws_service(context, 0);
183
184 bail:
185 lws_context_destroy(context);
186
187 return 0;
188 }
189