Adding files

.gitattributes

@@ -1,2 +1,6 @@
-# Auto detect text files and perform LF normalization
-* text=auto
+*.gitattributes   linguist-vendored
+util/mongoose.c   linguist-vendored
+util/mongoose.h   linguist-vendored
+
+.gitattributes	export-ignore
+util/*		export-ignore

util/websocket.c

@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2014 Cesanta Software Limited
+ * All rights reserved
+ */
+
+#include "mongoose.h"
+
+static sig_atomic_t s_signal_received = 0;
+static const char *s_http_port = "8000";
+static struct mg_serve_http_opts s_http_server_opts;
+static char server_pwd[100];
+static struct mg_connection *supernode_client = NULL;
+
+static void signal_handler(int sig_num) {
+  signal(sig_num, signal_handler);  // Reinstantiate signal handler
+  s_signal_received = sig_num;
+}
+
+//Display Message in console/terminal
+static void display(struct mg_connection *nc, char type[25]){
+  char addr[32];
+  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+  printf("%s\t%s\n", addr, type);
+}
+
+//Broadcast incoming message (from nc to all)
+static void broadcast(struct mg_connection *nc, const struct mg_str msg) {
+  char addr[32];
+  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+  printf("%s\tBroadcast\t[%d]\n", addr, (int)msg.len);
+  struct mg_connection *c;
+  for (c = mg_next(nc->mgr, NULL); c != NULL; c = mg_next(nc->mgr, c)) {
+    if (c == nc) continue; /* Don't send to the sender. */
+    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT,  msg.p, msg.len);
+  }
+}
+
+//Unicast message (to nc)
+static void unicast(struct mg_connection *nc, const struct mg_str msg) {
+  char addr[32];
+  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+  printf("%s\tUnicast\t[%d]\n", addr, (int)msg.len);
+  if(nc != NULL)
+    mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, msg.p, msg.len);
+}
+
+//Forward message (from nc to supernode)
+static void unicast_forward(struct mg_connection *nc, const struct mg_str msg) {
+  char addr[32];
+  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+  printf("%s\tForward\t[%d]\n", addr, (int)msg.len);
+  if(supernode_client != NULL)
+    mg_send_websocket_frame(supernode_client, WEBSOCKET_OP_TEXT, msg.p, msg.len);
+  else
+    printf("SuperNode client is offline!\n");
+}
+
+//Request message (from nc to supernode)
+static void unicast_request(struct mg_connection *nc, const struct mg_str msg) {
+  if(supernode_client == NULL){
+    printf("SuperNode client is offline!\n");
+    return;
+  }
+  char addr[32], buf[500];
+  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+  printf("%s\tRequest\t[%d]\n", addr, (int)msg.len-1);
+  snprintf(buf, sizeof(buf), "?%s %.*s", addr, (int) msg.len-1, msg.p+1);
+  mg_send_websocket_frame(supernode_client, WEBSOCKET_OP_TEXT, buf, strlen(buf));
+}
+
+//Reply message (from supernode)
+static void unicast_reply(const struct mg_str msg) {
+  if(supernode_client == NULL){
+    printf("SuperNode client is offline!\n");
+    return;
+  }
+  //Get receiver address from msg
+  char receiverAddr[32];
+  int index = (int)(strchr(msg.p, ' ') - msg.p) + 1;
+  snprintf(receiverAddr, sizeof(receiverAddr), "%.*s", index, msg.p);
+  printf("%s\tReply\t[%d]\n", receiverAddr, (int)msg.len - index);
+  //send msg to receiver
+  struct mg_connection *c;
+  for (c = mg_next(supernode_client->mgr, NULL); c != NULL; c = mg_next(supernode_client->mgr, c)) {
+    char addr[32];
+    mg_sock_addr_to_str(&c->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+    if (!strcmp(receiverAddr,addr)) 
+      mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT,  msg.p + index, msg.len - index);
+  }
+}
+
+static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
+  switch (ev) {
+    case MG_EV_WEBSOCKET_HANDSHAKE_DONE: {
+      /*New websocket connection*/
+      display(nc, "+Connected+");
+      break;
+    }
+    case MG_EV_WEBSOCKET_FRAME: {
+      struct websocket_message *wm = (struct websocket_message *) ev_data;
+      /* New websocket message*/
+      struct mg_str d = {(char *) wm->data, wm->size};
+      if (d.p[0] == '$'){
+        char pass[100];
+        snprintf(pass, sizeof(pass), "%.*s",(int)d.len-1, &d.p[1]);
+        if(!strcmp(pass,server_pwd)){
+          if(supernode_client!=NULL)
+            unicast(supernode_client,mg_mk_str("$Another login is encountered! Please close/refresh this window"));
+          supernode_client = nc;
+          unicast(supernode_client,mg_mk_str("$Access Granted!"));
+          display(nc, "*Became SuperNode*");
+        }else
+          unicast(nc,mg_mk_str("$Access Denied!"));
+      }
+      else if (d.p[0] == '?')
+        unicast_request(nc,d);
+      else if (nc == supernode_client)
+        unicast_reply(d);
+      else
+        unicast_forward(nc,d);
+      break;
+    }
+    case MG_EV_HTTP_REQUEST: {
+      mg_serve_http(nc, (struct http_message *) ev_data, s_http_server_opts);
+      break;
+    }
+    case MG_EV_CLOSE: {
+      /* Disconnect websocket*/
+      if(nc == supernode_client){
+        supernode_client = NULL;
+        display(nc,"!SuperNode Disconnected!");
+      }else
+        display(nc, "-Disconnected-");
+      break;
+    }
+  }
+}
+
+int main(int argc, char** argv) {
+
+  if(argc<=1){
+    printf("Enter server password : ");
+    scanf("%s",server_pwd);
+  }
+  else
+    strcpy(server_pwd,argv[1]);
+
+  struct mg_mgr mgr;
+  struct mg_connection *nc;
+
+  signal(SIGTERM, signal_handler);
+  signal(SIGINT, signal_handler);
+  setvbuf(stdout, NULL, _IOLBF, 0);
+  setvbuf(stderr, NULL, _IOLBF, 0);
+
+  mg_mgr_init(&mgr, NULL);
+
+  nc = mg_bind(&mgr, s_http_port, ev_handler);
+  mg_set_protocol_http_websocket(nc);
+  s_http_server_opts.document_root = ".";  // Serve current directory
+  s_http_server_opts.enable_directory_listing = "no";
+
+  printf("Started on port %s\n", s_http_port);
+  while (s_signal_received == 0) {
+    mg_mgr_poll(&mgr, 200);
+  }
+  mg_mgr_free(&mgr);
+
+  return 0;
+}