How do I extract IP address and port number from NSData - objective-c

Question

- (void)readData{
int err;
int sock;
struct sockaddr_storage addr;
socklen_t addrLen;
uint8_t buffer[65536];
ssize_t bytesRead;
sock = CFSocketGetNative(self->_cfSocket);
addrLen = sizeof(addr);
bytesRead = recvfrom(sock, buffer, sizeof(buffer), 0, (struct sockaddr *) &addr, &addrLen);
if (bytesRead < 0) {
err = errno;
} else if (bytesRead == 0) {
err = EPIPE;
} else {
NSData * dataObj;
NSData * addrObj;
err = 0;
dataObj = [NSData dataWithBytes:buffer length:bytesRead];
addrObj = [NSData dataWithBytes:&addr length:addrLen ];
// Tell the delegate about the data.
NSLog(#"receive data");
if ( (self.delegate != nil) && [self.delegate respondsToSelector:#selector(socket:didReceiveData:fromAddress:)] ) {
[self.delegate socket:self didReceiveData:dataObj fromAddress:addrObj];
}
}
if (err != 0) {
NSLog(#"Did Receive Error");
}
}
addrObj is NSData, How do I extract IP address and port number from addrObj?

Answer 1

I think you don't need to use a NSData object to extract the address. I use the following code to extract the IP address and port from which I read:
- (void)readData
{
int sock = CFSocketGetNative(self.cfSocket);
struct sockaddr_storage address;
socklen_t len = sizeof(address);
uint8_t buffer[65536];
ssize_t bytesRead = recvfrom(sock, buffer, sizeof(buffer), 0,
(struct sockaddr *) &address, &len);
int error = (bytesRead < 0) ? errno : 0;
NSLog(#"%zi bytes read from %s:%d...", bytesRead,
inet_ntoa(((struct sockaddr_in*)&address)->sin_addr),
((struct sockaddr_in*)&address)->sin_port);
...
}
Sample output:
2011-05-04 10:41:57.051,-[myClass readData],5 bytes read from 10.112.15.81:37259...
2011-05-04 10:41:57.052,-[myClass readData] read:
"Hello"