From 642bf87cfd30394d4440c531f22e61ecce5bc49d Mon Sep 17 00:00:00 2001
From: Benjamin Franzke <benjaminfranzke@googlemail.com>
Date: Thu, 8 Nov 2012 21:21:30 +0100
Subject: Add a very simple prisoner dilemma server

---
 .gitignore  |  1 +
 Makefile    |  5 +++-
 pd_server.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 pd_server.c

diff --git a/.gitignore b/.gitignore
index 4007296..188150f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 tit4tat
 prisoners_dilemma
+pd_server
diff --git a/Makefile b/Makefile
index 9f8ad86..23902ff 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,11 @@
-all: tit4tat prisoners_dilemma
+all: pd_server tit4tat prisoners_dilemma
 
 tit4tat: tit4tat.c
 	gcc -std=c99 -Wall -o $@ $<
 
+pd_server: pd_server.c
+	gcc -o $@ $<
+
 prisoners_dilemma: prisoners_dilemma.pl
 	gplc -o $@ $<
 
diff --git a/pd_server.c b/pd_server.c
new file mode 100644
index 0000000..d0b2315
--- /dev/null
+++ b/pd_server.c
@@ -0,0 +1,83 @@
+#include <stdio.h> 
+#include <stdlib.h> 
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+enum {
+	COORPERATION = 'c',
+	DEFECTION = 'd'
+}; 
+
+int pay(int a, int b) 
+{ 
+        if (a == COORPERATION && b == DEFECTION)    return 1; 
+        if (a == DEFECTION    && b == DEFECTION)    return 2; 
+        if (a == COORPERATION && b == COORPERATION) return 3; 
+        if (a == DEFECTION    && b == COORPERATION) return 4; 
+
+        exit(EXIT_FAILURE); 
+} 
+
+int
+main(int argc, char *argv[])
+{
+	int sock, player[2], read_fd;
+	struct sockaddr_in serv_addr;
+	int port = 8068;
+	int rounds, i;
+	int optval = 1;
+
+	rounds = atoi(argv[1]);
+
+	sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock < 0)
+		return EXIT_FAILURE;
+	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+		   &optval, sizeof optval);
+	serv_addr.sin_family = AF_INET;
+	serv_addr.sin_addr.s_addr = INADDR_ANY;
+	serv_addr.sin_port = htons(port);
+	if (bind(sock, (struct sockaddr *) &serv_addr,
+		 sizeof(serv_addr)) < 0) {
+		fprintf(stderr, "Failed to bind: %s\n",
+			strerror(errno));
+		return EXIT_FAILURE;
+	}
+	listen(sock, 2);
+
+	for (i = 0; i < 2; ++i) {
+		player[i] = accept(sock, NULL, NULL);
+	}
+	int a_payment = 0, b_payment = 0;
+	for (i = 0; i < rounds; ++i) {
+		char a, b;
+		read(player[0], &a, 1);
+		read(player[1], &b, 1);
+
+		if (a != 'c' && a != 'd') {
+			printf("a sent incorrect char: %c\n", a);
+			continue;
+		}
+		if (b != 'c' && b != 'd') {
+			printf("b sent incorrect char: %c\n", b);
+			continue;
+		}
+
+                a_payment += pay(a, b); 
+                b_payment += pay(b, a); 
+
+                printf("A [%c]: %d Euro\tB [%c]: %d Euro\t\t\tA: %d\tB: %d\n", 
+                       a, pay(a, b), b, pay(b, a), a_payment, b_payment); 
+
+		write(player[0], &b, 1);
+		write(player[1], &a, 1);
+	}
+	close(player[0]);
+	close(player[1]);
+	close(sock);
+}
-- 
cgit