updated

tests/intercept/udp_server.c

@@ -0,0 +1,71 @@
+#include <stdio.h>      /* standard C i/o facilities */
+#include <stdlib.h>     /* needed for atoi() */
+#include <unistd.h>     /* defines STDIN_FILENO, system calls,etc */
+#include <sys/types.h>  /* system data type definitions */
+#include <sys/socket.h> /* socket specific definitions */
+#include <netinet/in.h> /* INET constants and stuff */
+#include <arpa/inet.h>  /* IP address conversion stuff */
+#include <netdb.h>      /* gethostbyname */
+
+/* this routine echos any messages (UDP datagrams) received */
+
+#define MAXBUF 1024*10
+
+void echo( int sd ) {
+  int len,n;
+  char bufin[MAXBUF];
+  struct sockaddr_in remote;
+
+  /* need to know how big address struct is, len must be set before the
+     call to recvfrom!!! */
+  len = sizeof(remote);
+  long count = 0;
+
+  while (1) {
+    sleep(1);
+    count++;
+
+    n=recvfrom(sd,bufin,MAXBUF,0,(struct sockaddr *)&remote,&len);
+
+    /* print out the address of the sender */
+    printf("Got a datagram from %s port %d\n",
+           inet_ntoa(remote.sin_addr), ntohs(remote.sin_port));
+
+    if (n<0) {
+      perror("Error receiving data");
+    } else {
+      printf("GOT %d BYTES (count = %d)\n",n, count);
+      sendto(sd,bufin,n,0,(struct sockaddr *)&remote,len);
+    }
+  }
+}
+
+int main() {
+  int ld, length;
+  struct sockaddr_in skaddr;
+
+  if ((ld = socket( PF_INET, SOCK_DGRAM, 0 )) < 0) {
+    printf("Problem creating socket\n");
+    exit(1);
+  }
+
+  skaddr.sin_family = AF_INET;
+  skaddr.sin_addr.s_addr = htonl(INADDR_ANY);
+  skaddr.sin_port = htons(8888);
+
+  if (bind(ld, (struct sockaddr *) &skaddr, sizeof(skaddr))<0) {
+    printf("Problem binding\n");
+    exit(0);
+  }
+/*
+  length = sizeof( skaddr );
+  if (getsockname(ld, (struct sockaddr *) &skaddr, &length)<0) {
+    printf("Error getsockname\n");
+    exit(1);
+  }
+  */
+  printf("The server UDP port number is %d\n",ntohs(skaddr.sin_port));
+  /* Go echo every datagram we get */
+  echo(ld);
+  return 0;
+}