review.tizen.org Git - platform/upstream/libwebsockets.git/blob

   1 /*
   2  * lws-minimal-http-client
   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;
  20 static struct lws *client_wsi;
  21
  22 static int
  23 callback_http(struct lws *wsi, enum lws_callback_reasons reason,
  24               void *user, void *in, size_t len)
  25 {
  26         char val[32];
  27         int n;
  28
  29         switch (reason) {
  30
  31         /* because we are protocols[0] ... */
  32         case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
  33                 lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
  34                          in ? (char *)in : "(null)");
  35                 client_wsi = NULL;
  36                 break;
  37
  38         case LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER:
  39         {
  40                  unsigned char **p = (unsigned char **)in, *end = (*p) + len;
  41
  42                  /*
  43                   * How to send a custom header in the request to the server
  44                   */
  45
  46                  if (lws_add_http_header_by_name(wsi,
  47                                  (const unsigned char *)"dnt",
  48                                  (const unsigned char *)"1", 1, p, end))
  49                          return -1;
  50                 break;
  51         }
  52
  53         case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:
  54                 status = lws_http_client_http_response(wsi);
  55                 lwsl_user("Connected with server response: %d\n", status);
  56
  57                 /*
  58                  * How to query custom headers (http 1.x only at the momemnt)
  59                  *
  60                  * warmcat.com sends a custom header "test-custom-header" for
  61                  * testing, it has the fixed value "hello".
  62                  */
  63
  64                 n = lws_hdr_custom_length(wsi, "test-custom-header:", 19);
  65                 if (n < 0)
  66                         lwsl_notice("%s: Can't find test-custom-header\n",
  67                                     __func__);
  68                 else {
  69                         if (lws_hdr_custom_copy(wsi, val, sizeof(val),
  70                                                 "test-custom-header:", 19) < 0)
  71                                 lwsl_notice("%s: custom header too long\n",
  72                                             __func__);
  73                         else
  74                                 lwsl_notice("%s: custom header: '%s'\n",
  75                                                 __func__, val);
  76                 }
  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 #if 0  /* enable to dump the html */
  83                 {
  84                         const char *p = in;
  85
  86                         while (len--)
  87                                 if (*p < 0x7f)
  88                                         putchar(*p++);
  89                                 else
  90                                         putchar('.');
  91                 }
  92 #endif
  93                 return 0; /* don't passthru */
  94
  95         /* uninterpreted http content */
  96         case LWS_CALLBACK_RECEIVE_CLIENT_HTTP:
  97                 {
  98                         char buffer[1024 + LWS_PRE];
  99                         char *px = buffer + LWS_PRE;
 100                         int lenx = sizeof(buffer) - LWS_PRE;
 101
 102                         if (lws_http_client_read(wsi, &px, &lenx) < 0)
 103                                 return -1;
 104                 }
 105                 return 0; /* don't passthru */
 106
 107         case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:
 108                 lwsl_user("LWS_CALLBACK_COMPLETED_CLIENT_HTTP\n");
 109                 client_wsi = NULL;
 110                 bad = status != 200;
 111                 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
 112                 break;
 113
 114         case LWS_CALLBACK_CLOSED_CLIENT_HTTP:
 115                 client_wsi = NULL;
 116                 bad = status != 200;
 117                 lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
 118                 break;
 119
 120         default:
 121                 break;
 122         }
 123
 124         return lws_callback_http_dummy(wsi, reason, user, in, len);
 125 }
 126
 127 static const struct lws_protocols protocols[] = {
 128         {
 129                 "http",
 130                 callback_http,
 131                 0,
 132                 0,
 133         },
 134         { NULL, NULL, 0, 0 }
 135 };
 136
 137 static void
 138 sigint_handler(int sig)
 139 {
 140         interrupted = 1;
 141 }
 142
 143 int main(int argc, const char **argv)
 144 {
 145         struct lws_context_creation_info info;
 146         struct lws_client_connect_info i;
 147         struct lws_context *context;
 148         const char *p;
 149         int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
 150                    /*
 151                     * For LLL_ verbosity above NOTICE to be built into lws,
 152                     * lws must have been configured and built with
 153                     * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE
 154                     *
 155                     * | LLL_INFO   | LLL_PARSER  | LLL_HEADER | LLL_EXT |
 156                     *   LLL_CLIENT | LLL_LATENCY | LLL_DEBUG
 157                     */ ;
 158
 159         signal(SIGINT, sigint_handler);
 160
 161         if ((p = lws_cmdline_option(argc, argv, "-d")))
 162                 logs = atoi(p);
 163
 164         lws_set_log_level(logs, NULL);
 165         lwsl_user("LWS minimal http client Custom Headers [-d<verbosity>] [-l] [--h1]\n");
 166
 167         memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
 168         info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
 169         info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */
 170         info.protocols = protocols;
 171         /*
 172          * since we know this lws context is only ever going to be used with
 173          * one client wsis / fds / sockets at a time, let lws know it doesn't
 174          * have to use the default allocations for fd tables up to ulimit -n.
 175          * It will just allocate for 1 internal and 1 (+ 1 http2 nwsi) that we
 176          * will use.
 177          */
 178         info.fd_limit_per_thread = 1 + 1 + 1;
 179
 180 #if defined(LWS_WITH_MBEDTLS)
 181         /*
 182          * OpenSSL uses the system trust store.  mbedTLS has to be told which
 183          * CA to trust explicitly.
 184          */
 185         info.client_ssl_ca_filepath = "./warmcat.com.cer";
 186 #endif
 187
 188         context = lws_create_context(&info);
 189         if (!context) {
 190                 lwsl_err("lws init failed\n");
 191                 return 1;
 192         }
 193
 194         memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */
 195         i.context = context;
 196
 197         if (!lws_cmdline_option(argc, argv, "-n"))
 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         /* currently custom headers receive only works with h1 */
 210         i.alpn = "http/1.1";
 211
 212         i.path = "/";
 213         i.host = i.address;
 214         i.origin = i.address;
 215         i.method = "GET";
 216
 217         i.protocol = protocols[0].name;
 218         i.pwsi = &client_wsi;
 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 }