/* * lws-minimal-http-client * * Copyright (C) 2018 Andy Green * * This file is made available under the Creative Commons CC0 1.0 * Universal Public Domain Dedication. * * This demonstrates the a minimal http client using lws. * * It visits https://warmcat.com/ and receives the html page there. You * can dump the page data by changing the #if 0 below. */ #include #include #include static int interrupted; static struct lws *client_wsi; static int callback_http(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; /* chunks of chunked content, with header removed */ case LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ: lwsl_user("RECEIVE_CLIENT_HTTP_READ: read %d\n", (int)len); #if 0 /* enable to dump the html */ { const char *p = in; while (len--) if (*p < 0x7f) putchar(*p++); else putchar('.'); } #endif return 0; /* don't passthru */ /* uninterpreted http content */ case LWS_CALLBACK_RECEIVE_CLIENT_HTTP: { char buffer[1024 + LWS_PRE]; char *px = buffer + LWS_PRE; int lenx = sizeof(buffer) - LWS_PRE; if (lws_http_client_read(wsi, &px, &lenx) < 0) return -1; } return 0; /* don't passthru */ case LWS_CALLBACK_COMPLETED_CLIENT_HTTP: lwsl_user("LWS_CALLBACK_COMPLETED_CLIENT_HTTP\n"); client_wsi = NULL; break; default: break; } return lws_callback_http_dummy(wsi, reason, user, in, len); } static const struct lws_protocols protocols[] = { { "http", callback_http, 0, 0, }, { NULL, NULL, 0, 0 } }; static void sigint_handler(int sig) { interrupted = 1; } static int findswitch(int argc, char **argv, const char *val) { while (--argc > 0) { if (!strcmp(argv[argc], val)) return argc; } return 0; } int main(int argc, char **argv) { struct lws_context_creation_info info; struct lws_client_connect_info i; struct lws_context *context; int logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE /* * For LLL_ verbosity above NOTICE to be built into lws, * lws must have been configured and built with * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE * * | LLL_INFO | LLL_PARSER | LLL_HEADER | LLL_EXT | * LLL_CLIENT | LLL_LATENCY | LLL_DEBUG */ ; int n = 0, m; signal(SIGINT, sigint_handler); /* you can set the log level on commandline with, eg, -d 15 */ m = findswitch(argc, argv, "-d"); if (m && m + 1 < argc) logs = atoi(argv[m + 1]); lws_set_log_level(logs, NULL); lwsl_user("LWS minimal http client\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 = "./warmcat.com.cer"; #endif 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 = "warmcat.com"; i.path = "/"; i.host = i.address; i.origin = i.address; i.ssl_connection = /* LCCSCF_NOT_H2 | */ LCCSCF_USE_SSL; i.method = "GET"; i.protocol = protocols[0].name; i.pwsi = &client_wsi; lws_client_connect_via_info(&i); while (n >= 0 && client_wsi && !interrupted) n = lws_service(context, 1000); lws_context_destroy(context); lwsl_user("Completed\n"); return 0; }