I am trying to set up a SilverLight policy server under MacOSX 10.7.2 (Lion). This requires that I create and bind a socket to port 943, since SilverLight requests the policy file on this port. Unfortunately, it seems I am unable to bind at that port, as the bind call fails with errno=49.
I suppose I do not have access to this port. Perhaps I need root privileges? Or do I need to forward this port to another one that I can bind? I'm a bit new to network programming, so any help is greatly appreciated! I've also attached my source code. Perhaps I'm doing something wrong, although it works fine if I use the SilverLight restricted ports 4502-4532, which SilverLight communicates on once the policy file is successfully served.
- (void) start {
CFSocketRef socket = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_STREAM, IPPROTO_TCP, 0, NULL, NULL);
if (!socket) {
[self errorWithName:@"Unable to create socket."];
return;
}
int reuse = true;
CFSocketNativeHandle fileDescriptor = CFSocketGetNative(socket);
if (setsockopt(fileDescriptor, SOL_SOCKET, SO_REUSEADDR,
(void *)&reuse, sizeof(int)) != 0) {
NSLog(@"Unable to set socket options.");
return;
}
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
address.sin_len = sizeof(address);
address.sin_family = AF_INET;
address.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
address.sin_port = htons(943);
CFDataRef addressData = CFDataCreate(NULL, (const UInt8 *)&address, sizeof(address));
[(id)addressData autorelease];
CFSocketError error = CFSocketSetAddress(socket, addressData);
if (error < 0) {
NSLog(@"Error bind %d\n", errno); //fails here for port 943.
return;
}
NSFileHandle *listeningHandle = [[NSFileHandle alloc]
initWithFileDescriptor:fileDescriptor
closeOnDealloc:YES];
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(receiveIncomingConnectionNotification:)
name:NSFileHandleConnectionAcceptedNotification
object:nil];
[listeningHandle acceptConnectionInBackgroundAndNotify];
}
Only root
has privileges for ports below 1024. Try running your code with sudo
and see if that fixes your issue.
Edit:
Also, check out man strerror
. It will take that relatively meaningless error code and give you a (slightly) more useful string.
#include <stdio.h>
#include <string.h>
int main (int argc, char const *argv[])
{
printf("%s\n", strerror(49) );
return 0;
}
Gives:
Can't assign requested address