/* * lws-minimal-ws-client * * Written in 2010-2019 by Andy Green * * This file is made available under the Creative Commons CC0 1.0 * Universal Public Domain Dedication. * * This demonstrates the a minimal ws client using lws. * * It connects to https://libwebsockets.org/ and makes a * wss connection to the dumb-increment protocol there. While * connected, it prints the numbers it is being sent by * dumb-increment protocol. */ #include #include #include static int interrupted, rx_seen, test; static struct lws *client_wsi; static int callback_dumb_increment(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len) { switch (reason) { /* because we are protocols[0] ... */ case LWS_CALLBACK_CLIENT_CONNECTION_ERROR: lwsl_err("CLIENT_CONNECTION_ERROR: %s\n", in ? (char *)in : "(null)"); client_wsi = NULL; break; case LWS_CALLBACK_CLIENT_ESTABLISHED: lwsl_user("%s: established\n", __func__); break; case LWS_CALLBACK_CLIENT_RECEIVE: lwsl_user("RX: %s\n", (const char *)in); rx_seen++; if (test && rx_seen == 10) interrupted = 1; break; case LWS_CALLBACK_CLIENT_CLOSED: client_wsi = NULL; break; default: break; } return lws_callback_http_dummy(wsi, reason, user, in, len); } static const struct lws_protocols protocols[] = { { "dumb-increment-protocol", callback_dumb_increment, 0, 0, }, { NULL, NULL, 0, 0 } }; static void sigint_handler(int sig) { interrupted = 1; } int main(int argc, const char **argv) { struct lws_context_creation_info info; struct lws_client_connect_info i; struct lws_context *context; const char *p; int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE /* for LLL_ verbosity above NOTICE to be built into lws, lws * must have been configured with -DCMAKE_BUILD_TYPE=DEBUG * instead of =RELEASE */ /* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */ /* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */ /* | LLL_DEBUG */; signal(SIGINT, sigint_handler); if ((p = lws_cmdline_option(argc, argv, "-d"))) logs = atoi(p); test = !!lws_cmdline_option(argc, argv, "-t"); lws_set_log_level(logs, NULL); lwsl_user("LWS minimal ws client rx [-d ] [--h2] [-t (test)]\n"); memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */ info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT; info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */ info.protocols = protocols; #if defined(LWS_WITH_MBEDTLS) /* * OpenSSL uses the system trust store. mbedTLS has to be told which * CA to trust explicitly. */ info.client_ssl_ca_filepath = "./libwebsockets.org.cer"; #endif /* * since we know this lws context is only ever going to be used with * one client wsis / fds / sockets at a time, let lws know it doesn't * have to use the default allocations for fd tables up to ulimit -n. * It will just allocate for 1 internal and 1 (+ 1 http2 nwsi) that we * will use. */ info.fd_limit_per_thread = 1 + 1 + 1; context = lws_create_context(&info); if (!context) { lwsl_err("lws init failed\n"); return 1; } memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */ i.context = context; i.port = 443; i.address = "libwebsockets.org"; i.path = "/"; i.host = i.address; i.origin = i.address; i.ssl_connection = LCCSCF_USE_SSL; i.protocol = protocols[0].name; /* "dumb-increment-protocol" */ i.pwsi = &client_wsi; if (lws_cmdline_option(argc, argv, "--h2")) i.alpn = "h2"; lws_client_connect_via_info(&i); while (n >= 0 && client_wsi && !interrupted) n = lws_service(context, 0); lws_context_destroy(context); lwsl_user("Completed %s\n", rx_seen > 10 ? "OK" : "Failed"); return rx_seen > 10; }