1 /*
2 * lws-minimal-http-client hugeurl
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/?fakeparam=<2KB> and receives the html
12 * page there. You 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;
20 static struct lws *client_wsi;
21
22 static const char * const uri =
23 "/?fakeparam="
24 "00000000000000000000000000000000000000000000000000"
25 "00000000000000000000000000000000000000000000000000"
26 "00000000000000000000000000000000000000000000000000"
27 "00000000000000000000000000000000000000000000000000"
28 "00000000000000000000000000000000000000000000000000"
29 "00000000000000000000000000000000000000000000000000"
30 "00000000000000000000000000000000000000000000000000"
31 "00000000000000000000000000000000000000000000000000"
32 "00000000000000000000000000000000000000000000000000"
33 "00000000000000000000000000000000000000000000000000" /* 500 */
34 "11111111111111111111111111111111111111111111111111"
35 "11111111111111111111111111111111111111111111111111"
36 "11111111111111111111111111111111111111111111111111"
37 "11111111111111111111111111111111111111111111111111"
38 "11111111111111111111111111111111111111111111111111"
39 "11111111111111111111111111111111111111111111111111"
40 "11111111111111111111111111111111111111111111111111"
41 "11111111111111111111111111111111111111111111111111"
42 "11111111111111111111111111111111111111111111111111"
43 "11111111111111111111111111111111111111111111111111" /* 1000 */
44 "22222222222222222222222222222222222222222222222222"
45 "22222222222222222222222222222222222222222222222222"
46 "22222222222222222222222222222222222222222222222222"
47 "22222222222222222222222222222222222222222222222222"
48 "22222222222222222222222222222222222222222222222222"
49 "22222222222222222222222222222222222222222222222222"
50 "22222222222222222222222222222222222222222222222222"
51 "22222222222222222222222222222222222222222222222222"
52 "22222222222222222222222222222222222222222222222222"
53 "22222222222222222222222222222222222222222222222222" /* 1500 */
54 "33333333333333333333333333333333333333333333333333"
55 "33333333333333333333333333333333333333333333333333"
56 "33333333333333333333333333333333333333333333333333"
57 "33333333333333333333333333333333333333333333333333"
58 "33333333333333333333333333333333333333333333333333"
59 "33333333333333333333333333333333333333333333333333"
60 "33333333333333333333333333333333333333333333333333"
61 "33333333333333333333333333333333333333333333333333"
62 "33333333333333333333333333333333333333333333333333"
63 "33333333333333333333333333333333333333333333333333" /* 2000 */
64 ;
65
66 static int
callback_http(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)67 callback_http(struct lws *wsi, enum lws_callback_reasons reason,
68 void *user, void *in, size_t len)
69 {
70 switch (reason) {
71
72 /* because we are protocols[0] ... */
73 case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
74 lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
75 in ? (char *)in : "(null)");
76 client_wsi = NULL;
77 break;
78
79 case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:
80 status = lws_http_client_http_response(wsi);
81 lwsl_user("Connected with server response: %d\n", status);
82 break;
83
84 /* chunks of chunked content, with header removed */
85 case LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ:
86 lwsl_user("RECEIVE_CLIENT_HTTP_READ: read %d\n", (int)len);
87 #if 0 /* enable to dump the html */
88 {
89 const char *p = in;
90
91 while (len--)
92 if (*p < 0x7f)
93 putchar(*p++);
94 else
95 putchar('.');
96 }
97 #endif
98 return 0; /* don't passthru */
99
100 /* uninterpreted http content */
101 case LWS_CALLBACK_RECEIVE_CLIENT_HTTP:
102 {
103 char buffer[1024 + LWS_PRE];
104 char *px = buffer + LWS_PRE;
105 int lenx = sizeof(buffer) - LWS_PRE;
106
107 if (lws_http_client_read(wsi, &px, &lenx) < 0)
108 return -1;
109 }
110 return 0; /* don't passthru */
111
112 case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:
113 client_wsi = NULL;
114 bad = status != 200;
115 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
116 break;
117
118 case LWS_CALLBACK_CLOSED_CLIENT_HTTP:
119 client_wsi = NULL;
120 bad = status != 200;
121 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
122 break;
123
124 default:
125 break;
126 }
127
128 return lws_callback_http_dummy(wsi, reason, user, in, len);
129 }
130
131 static const struct lws_protocols protocols[] = {
132 {
133 "http",
134 callback_http,
135 0,
136 0,
137 },
138 { NULL, NULL, 0, 0 }
139 };
140
141 static void
sigint_handler(int sig)142 sigint_handler(int sig)
143 {
144 interrupted = 1;
145 }
146
main(int argc,const char ** argv)147 int main(int argc, const char **argv)
148 {
149 struct lws_context_creation_info info;
150 struct lws_client_connect_info i;
151 struct lws_context *context;
152 const char *p;
153 int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
154 /* for LLL_ verbosity above NOTICE to be built into lws,
155 * lws must have been configured and built with
156 * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
157 /* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */
158 /* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */
159 /* | LLL_DEBUG */;
160
161 if ((p = lws_cmdline_option(argc, argv, "-d")))
162 logs = atoi(p);
163
164 signal(SIGINT, sigint_handler);
165 lws_set_log_level(logs, NULL);
166 lwsl_user("LWS minimal http client hugeurl [-d <verbosity>] [-l] [--h1]\n");
167
168 memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
169 info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
170 info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */
171 info.protocols = protocols;
172 info.pt_serv_buf_size = 8192;
173 /*
174 * since we know this lws context is only ever going to be used with
175 * one client wsis / fds / sockets at a time, let lws know it doesn't
176 * have to use the default allocations for fd tables up to ulimit -n.
177 * It will just allocate for 1 internal and 1 (+ 1 http2 nwsi) that we
178 * will use.
179 */
180 info.fd_limit_per_thread = 1 + 1 + 1;
181
182 #if defined(LWS_WITH_MBEDTLS)
183 /*
184 * OpenSSL uses the system trust store. mbedTLS has to be told which
185 * CA to trust explicitly.
186 */
187 info.client_ssl_ca_filepath = "./warmcat.com.cer";
188 #endif
189
190 context = lws_create_context(&info);
191 if (!context) {
192 lwsl_err("lws init failed\n");
193 return 1;
194 }
195
196 memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */
197 i.context = context;
198 i.ssl_connection = LCCSCF_USE_SSL;
199
200 if (lws_cmdline_option(argc, argv, "-l")) {
201 i.port = 7681;
202 i.address = "localhost";
203 i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
204 } else {
205 i.port = 443;
206 i.address = "warmcat.com";
207 }
208
209 if (lws_cmdline_option(argc, argv, "--h1"))
210 i.alpn = "http/1.1";
211
212 i.path = uri;
213 i.host = i.address;
214 i.origin = i.address;
215 i.method = "GET";
216 i.protocol = protocols[0].name;
217 i.pwsi = &client_wsi;
218
219 lws_client_connect_via_info(&i);
220
221 while (n >= 0 && client_wsi && !interrupted)
222 n = lws_service(context, 0);
223
224 lws_context_destroy(context);
225 lwsl_user("Completed: %s\n", bad? "failed": "OK");
226
227 return bad;
228 }
229