Allow to load remote config files with curl

different samples of use:

  ccminer -c http://127.0.0.1/ccminer.json

or dynamically from a web application :
  ccminer -c http://127.0.0.1/ccminer/config.php?h=linux

Signed-off-by: Tanguy Pruvot <tanguy.pruvot@gmail.com>

README.txt

@@ -225,6 +225,7 @@ features.
 >>> RELEASE HISTORY <<<
 
   August 2015...
+                  Allow to load remote config with curl (-c http://...)
                   Add Lyra2REv2 algo (Vertcoin/Zoom)
                   Restore WhirlpoolX algo (VNL)
                   Drop Animecoin support

ccminer.cpp

@@ -2522,13 +2522,15 @@ void parse_arg(int key, char *arg)
 		break;
 	case 'c': {
 		json_error_t err;
-		if (opt_config)
+		if (opt_config) {
 			json_decref(opt_config);
-#if JANSSON_VERSION_HEX >= 0x020000
-		opt_config = json_load_file(arg, 0, &err);
-#else
-		opt_config = json_load_file(arg, &err);
-#endif
+			opt_config = NULL;
+		}
+		if (arg && strstr(arg, "://")) {
+			opt_config = json_load_url(arg, &err);
+		} else {
+			opt_config = JSON_LOADF(arg, &err);
+		}
 		if (!json_is_object(opt_config)) {
 			applog(LOG_ERR, "JSON decode of %s failed", arg);
 			proper_exit(EXIT_CODE_USAGE);

configure.ac

@@ -1,4 +1,4 @@
-AC_INIT([ccminer], [1.6.6-dev])
+AC_INIT([ccminer], [1.6.6])
 
 AC_PREREQ([2.59c])
 AC_CANONICAL_SYSTEM

miner.h

@@ -245,10 +245,14 @@ void aligned_free(void *ptr);
 
 #if JANSSON_MAJOR_VERSION >= 2
 #define JSON_LOADS(str, err_ptr) json_loads((str), 0, (err_ptr))
+#define JSON_LOADF(str, err_ptr) json_load_file((str), 0, (err_ptr))
 #else
 #define JSON_LOADS(str, err_ptr) json_loads((str), (err_ptr))
+#define JSON_LOADF(str, err_ptr) json_load_file((str), (err_ptr))
 #endif
 
+json_t * json_load_url(char* cfg_url, json_error_t *err);
+
 #define USER_AGENT PACKAGE_NAME "/" PACKAGE_VERSION
 
 void sha256_init(uint32_t *state);

util.cpp

@@ -603,6 +603,51 @@ json_t *json_rpc_longpoll(CURL *curl, char *lp_url, struct pool_infos *pool, con
 	return json_rpc_call(curl, lp_url, userpass, req, false, true, keepalive, curl_err);
 }
 
+json_t *json_load_url(char* cfg_url, json_error_t *err)
+{
+	char err_str[CURL_ERROR_SIZE] = { 0 };
+	struct data_buffer all_data = { 0 };
+	int rc = 0; json_t *cfg = NULL;
+	CURL *curl = curl_easy_init();
+	if (unlikely(!curl)) {
+		applog(LOG_ERR, "Remote config init failed!");
+		return NULL;
+	}
+	curl_easy_setopt(curl, CURLOPT_URL, cfg_url);
+	curl_easy_setopt(curl, CURLOPT_FRESH_CONNECT, 1);
+	curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 15);
+	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, err_str);
+	curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
+	curl_easy_setopt(curl, CURLOPT_TCP_NODELAY, 1);
+	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, all_data_cb);
+	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &all_data);
+	if (opt_proxy) {
+		curl_easy_setopt(curl, CURLOPT_PROXY, opt_proxy);
+		curl_easy_setopt(curl, CURLOPT_PROXYTYPE, opt_proxy_type);
+	} else if (getenv("http_proxy")) {
+		if (getenv("all_proxy"))
+			curl_easy_setopt(curl, CURLOPT_PROXY, getenv("all_proxy"));
+		else if (getenv("ALL_PROXY"))
+			curl_easy_setopt(curl, CURLOPT_PROXY, getenv("ALL_PROXY"));
+		else
+			curl_easy_setopt(curl, CURLOPT_PROXY, "");
+	}
+	rc = curl_easy_perform(curl);
+	if (rc) {
+		applog(LOG_ERR, "Remote config read failed: %s", err_str);
+		goto err_out;
+	}
+	if (!all_data.buf || !all_data.len) {
+		applog(LOG_ERR, "Empty data received for config");
+		goto err_out;
+	}
+
+	cfg = JSON_LOADS((char*)all_data.buf, err);
+err_out:
+	curl_easy_cleanup(curl);
+	return cfg;
+}
+
 /**
  * Unlike malloc, calloc set the memory to zero
  */