added initial server/client code

2 files changed, 167 insertions, 0 deletions

diff --git a/src/net.c b/src/net.c
new file mode 100644
index 0000000..627f2b0
--- /dev/null
+++ b/src/net.c
@@ -0,0 +1,157 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include "net.h"
+
+/**
+ * Server side function; start server on specified port
+ * @param[in] port Port on which server should listen
+ * @return Listening socket
+ */
+int server_start(const char* port)
+{
+	int status;
+	int serversock;
+	struct addrinfo hints, *result, *tmp;
+
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_family = AF_UNSPEC;		// IPv4 or IPv6
+	hints.ai_socktype = SOCK_STREAM;	// TCP socket
+	hints.ai_flags = AI_PASSIVE;		// wildcard IP
+	hints.ai_protocol = 0;			// any protocol
+
+	status = getaddrinfo(NULL, port, &hints, &result);
+	if(status != 0)
+	{
+		printf("getaddrinfo: %s\n", gai_strerror(status));
+		exit(EXIT_FAILURE);
+	}
+
+	// iterate over linked addrinfo list and use first useable entry
+	for(tmp = result; tmp != NULL; tmp = tmp->ai_next)
+	{
+		int yes=1;
+
+		// create socket
+		serversock = socket(tmp->ai_family, tmp->ai_socktype, tmp->ai_protocol);
+		if(serversock == -1)
+			continue;
+
+		// try to reuse still open sockets in TIME_WAIT state
+		setsockopt(serversock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
+
+		// try to bind to address/port
+		if(bind(serversock, tmp->ai_addr, tmp->ai_addrlen) == 0)
+			break; // Success!
+
+		close(serversock);
+	}
+
+	if(tmp == NULL)
+	{
+		printf("failed to bind\n");
+		exit(EXIT_FAILURE);
+	}
+	freeaddrinfo(result);
+
+	// start listening
+	status = listen(serversock, 1);
+	if(status == -1)
+	{
+		printf("listen: %s\n", strerror(status));
+		exit(EXIT_FAILURE);
+	}
+
+	return serversock;
+}
+
+/**
+ * Server side function; accepts connections from clients
+ * @param[in] serversock Socket on which server is listening
+ * @param[in] count Number of clients that should connect
+ * @return List of $count open sockets with connections to clients
+ */
+int* server_get_players(int serversock, const uint8_t count)
+{
+	int* clientsocks;
+	int i;
+
+	assert(count < MAX_PLAYERS && count > 0);
+
+	clientsocks = malloc(count*sizeof(int));
+	assert(clientsocks != NULL);
+
+	// accept connections
+	for(i=0; i<count; i++)
+	{
+		int sock;
+		struct sockaddr_storage addr;
+		socklen_t addrlen = sizeof(addr);
+		sock = accept(serversock, (struct sockaddr*) &addr, &addrlen);
+		if(sock == -1)
+		{
+			printf("accept: %s\n", strerror(sock));
+			exit(EXIT_FAILURE);
+		}
+		//printf("new client connected: %s\n", inet_ntop(sock.ss_family, get_in_addr((struct sockaddr*)&sock), INET6_ADDRSTRLEN));
+		printf("new client connected (%d/%d)\n", i+1, count);
+		clientsocks[i] = sock;
+	}
+
+	return clientsocks;
+}
+
+/**
+ * Client side function; connects to specified host:port
+ * @param[in] host Hostname of server
+ * @param[in] port Port of server
+ * @return Socket with open connection to server
+ */
+int client_connect_server(const char* host, const char* port)
+{
+	int status;
+	int sock;
+	struct addrinfo hints, *result, *tmp;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;		// IPv4 or IPv6
+	hints.ai_socktype = SOCK_STREAM;	// TCP socket
+
+	status = getaddrinfo(host, port, &hints, &result);
+	if(status != 0)
+	{
+		printf("getaddrinfo: %s\n", gai_strerror(status));
+		exit(EXIT_FAILURE);
+	}
+
+	// connect to first result in linked addrinfo list
+	for(tmp = result; tmp != NULL; tmp = tmp->ai_next)
+	{
+		// create socket
+		sock = socket(tmp->ai_family, tmp->ai_socktype, tmp->ai_protocol);
+		if(sock == -1)
+			continue;
+
+		// connect!
+		if(connect(sock, tmp->ai_addr, tmp->ai_addrlen) != -1)
+			break;	// Success!
+
+		close(sock);
+	}
+
+	if(tmp == NULL)
+	{
+		printf("failed to connect\n");
+		exit(EXIT_FAILURE);
+	}
+	freeaddrinfo(result);
+
+	return sock;
+}
+
+
diff --git a/src/net.h b/src/net.h
new file mode 100644
index 0000000..f29100a
--- /dev/null
+++ b/src/net.h
@@ -0,0 +1,10 @@
+#ifndef OXEN_NET_H
+#define OXEN_NET_H
+
+#define MAX_PLAYERS 10
+
+int server_start(const char* port);
+int* server_get_players(int serversock, const uint8_t count);
+int client_connect_server(const char* host, const char* port);
+
+#endif // OXEN_NET_H