[601] in linux-net channel archive
Inet Addresses in AF_INET UDP?
daemon@ATHENA.MIT.EDU (Chris Austin)
Fri Jun 30 13:46:10 1995
Date: Fri, 30 Jun 1995 08:05:38 +0000 ( )
From: Chris Austin <caustin@direct.ca>
To: linux-net@vger.rutgers.edu
Hi there,
I'm trying to get the address from a connectionless internet UDP socket
and I just can't seem to do it! I've included a small snippet of code
from what I've done so far. Here's the output I get everytime I run it :-
DEBUG: HOST = 5.0.0.0 PORT = 0
DEBUG: network order IP = 5 host order IP = 83886080
DEBUG: dotted-quad IP = 5.0.0.0
DEBUG: addr = 83886080 ipaddr = 5.0.0.0
If someone could please take a quick peek at this code and tell me what
I'm missing? Both the client and server are running thru loopback,
although I have tried it from a remote site and got pretty much the same
results. I have also tried this under kernel 1.2.9, 1.3.4 and 1.3.5.
Everything compiles fine with gcc 2.6.3 with -Wall, and I've included the
correct header files, ie arpa/inet.h, netinet/in.h etc etc
net_sockfd, mud_sockfd and shutdown are globals...
void server_loop(void)
{
fd_set input_set; /*, output_set, except_set;*/
while (!shutdown) {
FD_ZERO(&input_set);
FD_SET(net_sockfd, &input_set);
FD_SET(mud_sockfd, &input_set);
errno = 0;
if (select(mud_sockfd, &input_set, (fd_set *) 0, (fd_set *) 0, 0) < 0) {
fprintf(stderr, "Waking up to process signal\n");
}
else {
if (FD_ISSET(net_sockfd, &input_set))
recv_net_message();
if (FD_ISSET(mud_sockfd, &input_set))
recv_mud_message();
}
}
}
void recv_net_message(void)
{
struct sockaddr_in remote_address;
int numbytes, addr_len;
char message[MAX_NET_MESSAGE];
unsigned long addr;
char ipaddr[30];
numbytes = recvfrom(net_sockfd, message, MAX_NET_MESSAGE, 0, (struct sockaddr *) &remote_address, &addr_len);
if (numbytes < 0)
fprintf(stderr, "ZERO bytes received on net socket\n");
fprintf(stderr, "DEBUG: HOST = %s PORT = %d\n", inet_ntoa(remote_address.sin_addr), ntohs(remote_address.sin_port));
fprintf(stderr, "DEBUG: network hex IP = %lu host hex IP = %lu\n", remote_address.sin_addr.s_addr,
ntohl(remote_address.sin_addr.s_addr));
fprintf(stderr, "DEBUG: dotted-quad IP = %s\n", inet_ntoa(remote_address.sin_addr));
addr = ntohl(remote_address.sin_addr.s_addr);
sprintf(ipaddr, "%d.%d.%d.%d", (int) ((addr & 0xFF000000) >> 24),
(int) ((addr & 0x00FF0000) >> 16),
(int) ((addr & 0x0000FF00) >> 8),
(int) ((addr & 0x000000FF)));
fprintf(stderr, "DEBUG: addr = %lu ipaddr = %s\n", addr, ipaddr);
}
void init_net_socket(int port)
{
struct sockaddr_in serv_addr;
/* Open our Internet UDP socket */
if ((net_sockfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
fprintf(stderr, "Can't open internet datagram socket.\n");
exit(1);
}
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
serv_addr.sin_port = htons(port);
if (bind(net_sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
fprintf(stderr, "Can't bind local address, port = %d\n", port);
exit(1);
}
}
void init_mud_socket(void)
{
if ((mud_sockfd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
fprintf(stderr, "Can't open unix datagram socket.\n");
exit(1);
}
unlink(MUDSOCK_PATH);
bzero((char *) &mud_addr, sizeof(mud_addr));
mud_addr.sun_family = AF_UNIX;
strcpy(mud_addr.sun_path, MUDSOCK_PATH);
mudaddrlen = sizeof(mud_addr.sun_family) + strlen(mud_addr.sun_path);
if (bind(mud_sockfd, (struct sockaddr *) &mud_addr, mudaddrlen) < 0) {
fprintf(stderr, "Can't bind local mud socket\n");
exit(1);
}
}
