TCP Listening

src/coincerd.c

@@ -16,7 +16,7 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-
+#include <event2/event.h>
 
 #include "p2p.h"
 
@@ -40,9 +40,13 @@ int main(void)
 	 * - terminate on SIGTERM
 	 */
 
+	struct event_base *base;
+
 	int r;
-	if ((r = listen_init()) != 0)
+	if ((r = listen_init(&base)) != 0)
 		return r;
 
+	event_base_dispatch(base);
+
 	return 0;
 }

src/p2p.c

 #include <event2/listener.h>
 #include <event2/bufferevent.h>
+#include <event2/buffer.h>
+
 #include <arpa/inet.h>
 #include <string.h>
 #include <stdlib.h>
@@ -8,16 +10,36 @@
 
 #include "p2p.h"
 
+/**
+ * @brief callback for reading an input buffer
+ * @param bev buffer to read data from
+ * @param ctx optional programmer-defined data to be passed into this callback
+ */
 static void read_cb(struct bufferevent *bev, void *ctx)
 {
 
 	struct evbuffer *input = bufferevent_get_input(bev);
 	struct evbuffer *output = bufferevent_get_output(bev);
 
-	/* Copy all the data from the input buffer to the output buffer. */
+	/* FOR TESTING PURPOSES */
+
+	/* Display the input data */
+	size_t len = evbuffer_get_length(input);
+	char *data = (char *) malloc(len * sizeof(char));
+	evbuffer_copyout(input, data, len);
+	printf("Sending back: %s", data);
+	free(data);
+
+	/* Copy all the data from the input buffer to the output buffer */
 	evbuffer_add_buffer(output, input);
 }
 
+/**
+ * @brief callback for bufferevent event detection
+ * @param bev bufferevent on which the event occured
+ * @param events flags of the events occured
+ * @param ctx optional programmer-defined data to be passed into this callback
+ */
 static void event_cb(struct bufferevent *bev, short events, void *ctx)
 {
 
@@ -29,11 +51,19 @@ static void event_cb(struct bufferevent *bev, short events, void *ctx)
 	}
 }
 
+/**
+ * @brief callback for accepting a new connection
+ * @param listener incoming connection
+ * @param fd file descriptor for the new connection
+ * @param address routing information
+ * @param socklen size of address
+ * @param ctx optional programmer-defined data to be passed into this callback
+ */
 static void accept_conn_cb(struct evconnlistener *listener,
 	evutil_socket_t fd, struct sockaddr *address, int socklen,
 	void *ctx)
 {
-	/* Set up a bufferevent for a new connection. */
+	/* Set up a bufferevent for a new connection */
 	struct event_base *base = evconnlistener_get_base(listener);
 	struct bufferevent *bev = bufferevent_socket_new(
 		base, fd, BEV_OPT_CLOSE_ON_FREE);
@@ -41,8 +71,37 @@ static void accept_conn_cb(struct evconnlistener *listener,
 	bufferevent_setcb(bev, read_cb, NULL, event_cb, NULL);
 
 	bufferevent_enable(bev, EV_READ|EV_WRITE);
+
+
+	/* Display IP address of the one connecting to us */
+	char *s = NULL;
+
+	switch (address->sa_family) {
+		case AF_INET: {
+			struct sockaddr_in *addr_in = (struct sockaddr_in *) address;
+			s = malloc(INET_ADDRSTRLEN);
+			inet_ntop(AF_INET, &(addr_in->sin_addr), s, INET_ADDRSTRLEN);
+			break;
+		}
+		case AF_INET6: {
+			struct sockaddr_in6 *addr_in6 = (struct sockaddr_in6 *) address;
+			s = malloc(INET6_ADDRSTRLEN);
+			inet_ntop(AF_INET6, &(addr_in6->sin6_addr), s, INET6_ADDRSTRLEN);
+			break;
+		}
+		default:
+			break;
+	}
+
+	printf("%s has connected to you.\n", s);
+	free(s);
 }
 
+/**
+ * @brief callback for listener error detection
+ * @param listener listener on which the error occured
+ * @param ctx optional programmer-defined data to be passed into this callback
+ */
 static void accept_error_cb(struct evconnlistener *listener, void *ctx)
 {
 	struct event_base *base = evconnlistener_get_base(listener);
@@ -53,17 +112,16 @@ static void accept_error_cb(struct evconnlistener *listener, void *ctx)
 	event_base_loopexit(base, NULL);
 }
 
-int listen_init()
+int listen_init(struct event_base **base)
 {
 
-	struct event_base *base;
-	struct evconlistener *listener;
+	struct evconnlistener *listener;
 	struct sockaddr_in sin;
 
 	int port = 31070;
 
-	base = event_base_new();
-	if (!base) {
+	*base = event_base_new();
+	if (!*base) {
 		puts("Couldn't open event base");
 		return 1;
 	}
@@ -73,7 +131,7 @@ int listen_init()
 	sin.sin_addr.s_addr = htonl(0);
 	sin.sin_port = htons(port);
 
-	listener = evconnlistener_new_bind(base, accept_conn_cb, NULL,
+	listener = evconnlistener_new_bind(*base, accept_conn_cb, NULL,
 		LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,
 		(struct sockaddr*)&sin, sizeof(sin));
 	if (!listener) {
@@ -81,8 +139,6 @@ int listen_init()
 		return 1;
 	}
 	evconnlistener_set_error_cb(listener, accept_error_cb);
-
-	event_base_dispatch(base);
-
+	
 	return 0;
 }

src/p2p.h

 #ifndef P2P_H
 #define P2P_H
-int listen_init();
+
+#include <event2/event.h>
+
+/**
+ * @brief initialize listening and set up callbacks
+ * @param base event loop
+ * @return 1 if an error occured
+ * @return 0 if successfully initialized
+ */
+int listen_init(struct event_base **base);
 #endif