1*1c60b9acSAndroid Build Coastguard Worker /*
2*1c60b9acSAndroid Build Coastguard Worker  * lws-minimal-http-server-h2-long-poll
3*1c60b9acSAndroid Build Coastguard Worker  *
4*1c60b9acSAndroid Build Coastguard Worker  * Written in 2010-2019 by Andy Green <[email protected]>
5*1c60b9acSAndroid Build Coastguard Worker  *
6*1c60b9acSAndroid Build Coastguard Worker  * This file is made available under the Creative Commons CC0 1.0
7*1c60b9acSAndroid Build Coastguard Worker  * Universal Public Domain Dedication.
8*1c60b9acSAndroid Build Coastguard Worker  *
9*1c60b9acSAndroid Build Coastguard Worker  * This demonstrates an h2 server that supports "long poll"
10*1c60b9acSAndroid Build Coastguard Worker  * immortal client connections.  For simplicity it doesn't serve
11*1c60b9acSAndroid Build Coastguard Worker  * any regular files, you can add a mount to do it if you want.
12*1c60b9acSAndroid Build Coastguard Worker  *
13*1c60b9acSAndroid Build Coastguard Worker  * The protocol keeps the long poll h2 stream open, and sends
14*1c60b9acSAndroid Build Coastguard Worker  * the time on the stream once per minute.  Normally idle h2
15*1c60b9acSAndroid Build Coastguard Worker  * connections are closed by default within 30s, so this demonstrates
16*1c60b9acSAndroid Build Coastguard Worker  * the stream and network connection are operating as "immortal"
17*1c60b9acSAndroid Build Coastguard Worker  * on both sides.
18*1c60b9acSAndroid Build Coastguard Worker  *
19*1c60b9acSAndroid Build Coastguard Worker  * See http-client/minimal-http-client-h2-long-poll for the
20*1c60b9acSAndroid Build Coastguard Worker  * client example that connects and transitions the stream to the
21*1c60b9acSAndroid Build Coastguard Worker  * immortal long poll mode.
22*1c60b9acSAndroid Build Coastguard Worker  */
23*1c60b9acSAndroid Build Coastguard Worker 
24*1c60b9acSAndroid Build Coastguard Worker #include <libwebsockets.h>
25*1c60b9acSAndroid Build Coastguard Worker #include <string.h>
26*1c60b9acSAndroid Build Coastguard Worker #include <signal.h>
27*1c60b9acSAndroid Build Coastguard Worker 
28*1c60b9acSAndroid Build Coastguard Worker static int interrupted;
29*1c60b9acSAndroid Build Coastguard Worker 
30*1c60b9acSAndroid Build Coastguard Worker struct pss {
31*1c60b9acSAndroid Build Coastguard Worker 	struct lws *wsi;
32*1c60b9acSAndroid Build Coastguard Worker 	lws_sorted_usec_list_t sul;
33*1c60b9acSAndroid Build Coastguard Worker 	char pending;
34*1c60b9acSAndroid Build Coastguard Worker };
35*1c60b9acSAndroid Build Coastguard Worker 
36*1c60b9acSAndroid Build Coastguard Worker static const lws_retry_bo_t retry = {
37*1c60b9acSAndroid Build Coastguard Worker 	.secs_since_valid_ping = 5,
38*1c60b9acSAndroid Build Coastguard Worker 	.secs_since_valid_hangup = 10,
39*1c60b9acSAndroid Build Coastguard Worker };
40*1c60b9acSAndroid Build Coastguard Worker 
41*1c60b9acSAndroid Build Coastguard Worker static void
sul_cb(lws_sorted_usec_list_t * sul)42*1c60b9acSAndroid Build Coastguard Worker sul_cb(lws_sorted_usec_list_t *sul)
43*1c60b9acSAndroid Build Coastguard Worker {
44*1c60b9acSAndroid Build Coastguard Worker 	struct pss *pss = (struct pss *)lws_container_of(sul, struct pss, sul);
45*1c60b9acSAndroid Build Coastguard Worker 
46*1c60b9acSAndroid Build Coastguard Worker 	pss->pending = 1;
47*1c60b9acSAndroid Build Coastguard Worker 	lws_callback_on_writable(pss->wsi);
48*1c60b9acSAndroid Build Coastguard Worker 	/* interval 1min... longer than any normal timeout */
49*1c60b9acSAndroid Build Coastguard Worker 	lws_sul_schedule(lws_get_context(pss->wsi), 0, &pss->sul, sul_cb,
50*1c60b9acSAndroid Build Coastguard Worker 				60 * LWS_US_PER_SEC);
51*1c60b9acSAndroid Build Coastguard Worker }
52*1c60b9acSAndroid Build Coastguard Worker 
53*1c60b9acSAndroid Build Coastguard Worker static int
callback_http(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)54*1c60b9acSAndroid Build Coastguard Worker callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
55*1c60b9acSAndroid Build Coastguard Worker 	      void *in, size_t len)
56*1c60b9acSAndroid Build Coastguard Worker {
57*1c60b9acSAndroid Build Coastguard Worker 	struct pss * pss = (struct pss *)user;
58*1c60b9acSAndroid Build Coastguard Worker 	uint8_t buf[LWS_PRE + LWS_RECOMMENDED_MIN_HEADER_SPACE],
59*1c60b9acSAndroid Build Coastguard Worker 		*start = &buf[LWS_PRE], *p = start,
60*1c60b9acSAndroid Build Coastguard Worker 		*end = p + sizeof(buf) - LWS_PRE;
61*1c60b9acSAndroid Build Coastguard Worker 	int m, n;
62*1c60b9acSAndroid Build Coastguard Worker 
63*1c60b9acSAndroid Build Coastguard Worker 	switch (reason) {
64*1c60b9acSAndroid Build Coastguard Worker 	case LWS_CALLBACK_HTTP:
65*1c60b9acSAndroid Build Coastguard Worker 		lwsl_user("%s: connect\n", __func__);
66*1c60b9acSAndroid Build Coastguard Worker 		pss->wsi = wsi;
67*1c60b9acSAndroid Build Coastguard Worker 
68*1c60b9acSAndroid Build Coastguard Worker 		if (lws_add_http_common_headers(wsi, HTTP_STATUS_OK,
69*1c60b9acSAndroid Build Coastguard Worker 				"text/html",
70*1c60b9acSAndroid Build Coastguard Worker 				LWS_ILLEGAL_HTTP_CONTENT_LEN, /* no content len */
71*1c60b9acSAndroid Build Coastguard Worker 				&p, end))
72*1c60b9acSAndroid Build Coastguard Worker 			return 1;
73*1c60b9acSAndroid Build Coastguard Worker 		if (lws_finalize_write_http_header(wsi, start, &p, end))
74*1c60b9acSAndroid Build Coastguard Worker 			return 1;
75*1c60b9acSAndroid Build Coastguard Worker 
76*1c60b9acSAndroid Build Coastguard Worker 		sul_cb(&pss->sul);
77*1c60b9acSAndroid Build Coastguard Worker 		return 0;
78*1c60b9acSAndroid Build Coastguard Worker 
79*1c60b9acSAndroid Build Coastguard Worker 	case LWS_CALLBACK_CLOSED_HTTP:
80*1c60b9acSAndroid Build Coastguard Worker 		if (!pss)
81*1c60b9acSAndroid Build Coastguard Worker 			break;
82*1c60b9acSAndroid Build Coastguard Worker 		lws_sul_cancel(&pss->sul);
83*1c60b9acSAndroid Build Coastguard Worker 		break;
84*1c60b9acSAndroid Build Coastguard Worker 
85*1c60b9acSAndroid Build Coastguard Worker 	case LWS_CALLBACK_HTTP_WRITEABLE:
86*1c60b9acSAndroid Build Coastguard Worker 		if (!pss->pending)
87*1c60b9acSAndroid Build Coastguard Worker 			break;
88*1c60b9acSAndroid Build Coastguard Worker 		n = lws_snprintf((char *)p, sizeof(buf) - LWS_PRE, "%llu",
89*1c60b9acSAndroid Build Coastguard Worker 				 (unsigned long long)lws_now_usecs());
90*1c60b9acSAndroid Build Coastguard Worker 		m = lws_write(wsi, p, (unsigned int)n, LWS_WRITE_HTTP);
91*1c60b9acSAndroid Build Coastguard Worker 		if (m < n) {
92*1c60b9acSAndroid Build Coastguard Worker 			lwsl_err("ERROR %d writing to socket\n", n);
93*1c60b9acSAndroid Build Coastguard Worker 			return -1;
94*1c60b9acSAndroid Build Coastguard Worker 		}
95*1c60b9acSAndroid Build Coastguard Worker 		break;
96*1c60b9acSAndroid Build Coastguard Worker 	default:
97*1c60b9acSAndroid Build Coastguard Worker 		break;
98*1c60b9acSAndroid Build Coastguard Worker 	}
99*1c60b9acSAndroid Build Coastguard Worker 
100*1c60b9acSAndroid Build Coastguard Worker 	return lws_callback_http_dummy(wsi, reason, user, in, len);
101*1c60b9acSAndroid Build Coastguard Worker }
102*1c60b9acSAndroid Build Coastguard Worker 
103*1c60b9acSAndroid Build Coastguard Worker static struct lws_protocols protocols[] = {
104*1c60b9acSAndroid Build Coastguard Worker 	{ "http", callback_http, sizeof(struct pss), 0, 0, NULL, 0 },
105*1c60b9acSAndroid Build Coastguard Worker 	LWS_PROTOCOL_LIST_TERM
106*1c60b9acSAndroid Build Coastguard Worker };
107*1c60b9acSAndroid Build Coastguard Worker 
108*1c60b9acSAndroid Build Coastguard Worker 
sigint_handler(int sig)109*1c60b9acSAndroid Build Coastguard Worker void sigint_handler(int sig)
110*1c60b9acSAndroid Build Coastguard Worker {
111*1c60b9acSAndroid Build Coastguard Worker 	interrupted = 1;
112*1c60b9acSAndroid Build Coastguard Worker }
113*1c60b9acSAndroid Build Coastguard Worker 
main(int argc,const char ** argv)114*1c60b9acSAndroid Build Coastguard Worker int main(int argc, const char **argv)
115*1c60b9acSAndroid Build Coastguard Worker {
116*1c60b9acSAndroid Build Coastguard Worker 	struct lws_context_creation_info info;
117*1c60b9acSAndroid Build Coastguard Worker 	struct lws_context *context;
118*1c60b9acSAndroid Build Coastguard Worker 	const char *p;
119*1c60b9acSAndroid Build Coastguard Worker 	int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE;
120*1c60b9acSAndroid Build Coastguard Worker 
121*1c60b9acSAndroid Build Coastguard Worker 	signal(SIGINT, sigint_handler);
122*1c60b9acSAndroid Build Coastguard Worker 
123*1c60b9acSAndroid Build Coastguard Worker 	if ((p = lws_cmdline_option(argc, argv, "-d")))
124*1c60b9acSAndroid Build Coastguard Worker 		logs = atoi(p);
125*1c60b9acSAndroid Build Coastguard Worker 
126*1c60b9acSAndroid Build Coastguard Worker 	lws_set_log_level(logs, NULL);
127*1c60b9acSAndroid Build Coastguard Worker 	lwsl_user("LWS minimal http server h2 long poll\n");
128*1c60b9acSAndroid Build Coastguard Worker 
129*1c60b9acSAndroid Build Coastguard Worker 	memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
130*1c60b9acSAndroid Build Coastguard Worker 	info.port = 7681;
131*1c60b9acSAndroid Build Coastguard Worker #if defined(LWS_WITH_TLS)
132*1c60b9acSAndroid Build Coastguard Worker 	info.ssl_cert_filepath = "localhost-100y.cert";
133*1c60b9acSAndroid Build Coastguard Worker 	info.ssl_private_key_filepath = "localhost-100y.key";
134*1c60b9acSAndroid Build Coastguard Worker #endif
135*1c60b9acSAndroid Build Coastguard Worker 	info.protocols = protocols;
136*1c60b9acSAndroid Build Coastguard Worker 	info.options =
137*1c60b9acSAndroid Build Coastguard Worker 		LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT |
138*1c60b9acSAndroid Build Coastguard Worker 		LWS_SERVER_OPTION_VH_H2_HALF_CLOSED_LONG_POLL |
139*1c60b9acSAndroid Build Coastguard Worker 		LWS_SERVER_OPTION_HTTP_HEADERS_SECURITY_BEST_PRACTICES_ENFORCE;
140*1c60b9acSAndroid Build Coastguard Worker 
141*1c60b9acSAndroid Build Coastguard Worker 	/* the default validity check is 5m / 5m10s... -v = 5s / 10s */
142*1c60b9acSAndroid Build Coastguard Worker 
143*1c60b9acSAndroid Build Coastguard Worker 	if (lws_cmdline_option(argc, argv, "-v"))
144*1c60b9acSAndroid Build Coastguard Worker 		info.retry_and_idle_policy = &retry;
145*1c60b9acSAndroid Build Coastguard Worker 
146*1c60b9acSAndroid Build Coastguard Worker 	context = lws_create_context(&info);
147*1c60b9acSAndroid Build Coastguard Worker 	if (!context) {
148*1c60b9acSAndroid Build Coastguard Worker 		lwsl_err("lws init failed\n");
149*1c60b9acSAndroid Build Coastguard Worker 		return 1;
150*1c60b9acSAndroid Build Coastguard Worker 	}
151*1c60b9acSAndroid Build Coastguard Worker 
152*1c60b9acSAndroid Build Coastguard Worker 	while (n >= 0 && !interrupted)
153*1c60b9acSAndroid Build Coastguard Worker 		n = lws_service(context, 0);
154*1c60b9acSAndroid Build Coastguard Worker 
155*1c60b9acSAndroid Build Coastguard Worker 	lws_context_destroy(context);
156*1c60b9acSAndroid Build Coastguard Worker 
157*1c60b9acSAndroid Build Coastguard Worker 	return 0;
158*1c60b9acSAndroid Build Coastguard Worker }
159