1 /*
2 * lws-minimal-http-client-h2-rxflow
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 the a minimal http client using lws.
10 *
11 * It visits https://warmcat.com/ and receives the html page there. You
12 * can dump the page data by changing the #if 0 below.
13 */
14
15 #include <libwebsockets.h>
16 #include <string.h>
17 #include <signal.h>
18
19 static int interrupted, bad = 1, status, each = 1024;
20 static struct lws *client_wsi;
21
22 static const lws_retry_bo_t retry = {
23 .secs_since_valid_ping = 3,
24 .secs_since_valid_hangup = 10,
25 };
26
27 struct pss {
28 lws_sorted_usec_list_t sul;
29 struct lws *wsi;
30 };
31
32 /*
33 * Once we're established, we ask the server for another 1KB every 250ms
34 * until we have it all.
35 */
36
37 static void
drain_cb(lws_sorted_usec_list_t * sul)38 drain_cb(lws_sorted_usec_list_t *sul)
39 {
40 struct pss *pss = lws_container_of(sul, struct pss, sul);
41
42 lws_wsi_tx_credit(pss->wsi, LWSTXCR_PEER_TO_US, each);
43
44 lws_sul_schedule(lws_get_context(pss->wsi), 0, &pss->sul, drain_cb,
45 250 * LWS_US_PER_MS);
46 }
47
48
49 static int
callback_http(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)50 callback_http(struct lws *wsi, enum lws_callback_reasons reason,
51 void *user, void *in, size_t len)
52 {
53 struct pss *pss = (struct pss *)user;
54
55 switch (reason) {
56
57 /* because we are protocols[0] ... */
58 case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
59 lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
60 in ? (char *)in : "(null)");
61 interrupted = 1;
62 break;
63
64 case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:
65 {
66 char buf[128];
67
68 lws_get_peer_simple(wsi, buf, sizeof(buf));
69 status = (int)lws_http_client_http_response(wsi);
70
71 lwsl_user("Connected to %s, http response: %d\n",
72 buf, status);
73 }
74 pss->wsi = wsi;
75 lws_sul_schedule(lws_get_context(wsi), 0, &pss->sul, drain_cb,
76 250 * LWS_US_PER_MS);
77 break;
78
79 /* chunks of chunked content, with header removed */
80 case LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ:
81 lwsl_user("RECEIVE_CLIENT_HTTP_READ: read %d\n", (int)len);
82
83 #if 0 /* enable to dump the html */
84 {
85 const char *p = in;
86
87 while (len--)
88 if (*p < 0x7f)
89 putchar(*p++);
90 else
91 putchar('.');
92 }
93 #endif
94 return 0; /* don't passthru */
95
96 /* uninterpreted http content */
97 case LWS_CALLBACK_RECEIVE_CLIENT_HTTP:
98 {
99 char buffer[1024 + LWS_PRE];
100 char *px = buffer + LWS_PRE;
101 int lenx = sizeof(buffer) - LWS_PRE;
102
103 if (lws_http_client_read(wsi, &px, &lenx) < 0)
104 return -1;
105 }
106 return 0; /* don't passthru */
107
108 case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:
109 lwsl_user("LWS_CALLBACK_COMPLETED_CLIENT_HTTP\n");
110 interrupted = 1;
111 bad = status != 200;
112 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
113 break;
114
115 case LWS_CALLBACK_CLOSED_CLIENT_HTTP:
116 interrupted = 1;
117 bad = status != 200;
118 lws_sul_cancel(&pss->sul);
119 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
120 break;
121
122 default:
123 break;
124 }
125
126 return lws_callback_http_dummy(wsi, reason, user, in, len);
127 }
128
129 static const struct lws_protocols protocols[] = {
130 {
131 "http",
132 callback_http,
133 sizeof(struct pss),
134 0, 0, NULL, 0
135 },
136 LWS_PROTOCOL_LIST_TERM
137 };
138
139 static void
sigint_handler(int sig)140 sigint_handler(int sig)
141 {
142 interrupted = 1;
143 }
144
145 struct args {
146 int argc;
147 const char **argv;
148 };
149
150 static int
system_notify_cb(lws_state_manager_t * mgr,lws_state_notify_link_t * link,int current,int target)151 system_notify_cb(lws_state_manager_t *mgr, lws_state_notify_link_t *link,
152 int current, int target)
153 {
154 struct lws_context *context = mgr->parent;
155 struct lws_client_connect_info i;
156 struct args *a = lws_context_user(context);
157 const char *p;
158
159 if (current != LWS_SYSTATE_OPERATIONAL || target != LWS_SYSTATE_OPERATIONAL)
160 return 0;
161
162 lwsl_info("%s: operational\n", __func__);
163
164 memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */
165 i.context = context;
166 if (!lws_cmdline_option(a->argc, a->argv, "-n"))
167 i.ssl_connection = LCCSCF_USE_SSL;
168
169 if (lws_cmdline_option(a->argc, a->argv, "-l")) {
170 i.port = 7681;
171 i.address = "localhost";
172 i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
173 } else {
174 i.port = 443;
175 i.address = "warmcat.com";
176 }
177
178 if (lws_cmdline_option(a->argc, a->argv, "--nossl"))
179 i.ssl_connection = 0;
180
181 i.ssl_connection |= LCCSCF_H2_QUIRK_OVERFLOWS_TXCR |
182 LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM;
183
184 i.alpn = "h2";
185 if (lws_cmdline_option(a->argc, a->argv, "--h1"))
186 i.alpn = "http/1.1";
187
188 if ((p = lws_cmdline_option(a->argc, a->argv, "-p")))
189 i.port = atoi(p);
190
191 if (lws_cmdline_option(a->argc, a->argv, "-j"))
192 i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
193
194 if (lws_cmdline_option(a->argc, a->argv, "-k"))
195 i.ssl_connection |= LCCSCF_ALLOW_INSECURE;
196
197 if (lws_cmdline_option(a->argc, a->argv, "-m"))
198 i.ssl_connection |= LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK;
199
200 if (lws_cmdline_option(a->argc, a->argv, "-e"))
201 i.ssl_connection |= LCCSCF_ALLOW_EXPIRED;
202
203 if ((p = lws_cmdline_option(a->argc, a->argv, "-f"))) {
204 i.ssl_connection |= LCCSCF_H2_MANUAL_RXFLOW;
205 i.manual_initial_tx_credit = atoi(p);
206 lwsl_notice("%s: manual peer tx credit %d\n", __func__,
207 i.manual_initial_tx_credit);
208 }
209
210 if ((p = lws_cmdline_option(a->argc, a->argv, "--each")))
211 each = atoi(p);
212
213 /* the default validity check is 5m / 5m10s... -v = 3s / 10s */
214
215 if (lws_cmdline_option(a->argc, a->argv, "-v"))
216 i.retry_and_idle_policy = &retry;
217
218 if ((p = lws_cmdline_option(a->argc, a->argv, "--server")))
219 i.address = p;
220
221 if ((p = lws_cmdline_option(a->argc, a->argv, "--path")))
222 i.path = p;
223 else
224 i.path = "/";
225
226 i.host = i.address;
227 i.origin = i.address;
228 i.method = "GET";
229
230 i.protocol = protocols[0].name;
231 i.pwsi = &client_wsi;
232
233 return !lws_client_connect_via_info(&i);
234 }
235
main(int argc,const char ** argv)236 int main(int argc, const char **argv)
237 {
238 lws_state_notify_link_t notifier = { { NULL, NULL, NULL },
239 system_notify_cb, "app" };
240 lws_state_notify_link_t *na[] = { ¬ifier, NULL };
241 struct lws_context_creation_info info;
242 struct lws_context *context;
243 struct args args;
244 int n = 0;
245 // uint8_t memcert[4096];
246
247 args.argc = argc;
248 args.argv = argv;
249
250 signal(SIGINT, sigint_handler);
251
252 memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
253 lws_cmdline_option_handle_builtin(argc, argv, &info);
254
255 lwsl_user("LWS minimal http client [-d<verbosity>] [-l] [--h1]\n");
256
257 info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
258 info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */
259 info.protocols = protocols;
260 info.user = &args;
261 info.register_notifier_list = na;
262 info.timeout_secs = 10;
263 info.connect_timeout_secs = 30;
264
265 /*
266 * since we know this lws context is only ever going to be used with
267 * one client wsis / fds / sockets at a time, let lws know it doesn't
268 * have to use the default allocations for fd tables up to ulimit -n.
269 * It will just allocate for 1 internal and 1 (+ 1 http2 nwsi) that we
270 * will use.
271 */
272 info.fd_limit_per_thread = 1 + 1 + 1;
273
274 #if defined(LWS_WITH_MBEDTLS) || defined(USE_WOLFSSL)
275 /*
276 * OpenSSL uses the system trust store. mbedTLS has to be told which
277 * CA to trust explicitly.
278 */
279 info.client_ssl_ca_filepath = "./warmcat.com.cer";
280 #endif
281 #if 0
282 n = open("./warmcat.com.cer", O_RDONLY);
283 if (n >= 0) {
284 info.client_ssl_ca_mem_len = read(n, memcert, sizeof(memcert));
285 info.client_ssl_ca_mem = memcert;
286 close(n);
287 n = 0;
288 memcert[info.client_ssl_ca_mem_len++] = '\0';
289 }
290 #endif
291 context = lws_create_context(&info);
292 if (!context) {
293 lwsl_err("lws init failed\n");
294 return 1;
295 }
296
297 while (n >= 0 && !interrupted)
298 n = lws_service(context, 0);
299
300 lws_context_destroy(context);
301 lwsl_user("Completed: %s\n", bad ? "failed" : "OK");
302
303 return bad;
304 }
305