UDPREAD(3)UDPREAD(3)

NAME
udpread, udpwrite – read and write UDP packets

SYNOPSIS
#include <u.h>
#include <libc.h>
#include <ip.h>
typedef struct Udphdr Udphdr;
struct Udphdr
{
uchar    raddr[IPaddrlen];/* remote address and port */
uchar    laddr[IPaddrlen];/* local address and port */
uchar    rport[2];
uchar    lport[2];
};
long       udpread(int fd, Udphdr *hdr, void *data, long n)
long udpwrite(int fd, Udphdr *hdr, void *data, long n)

DESCRIPTION
Udpread and udpwrite read and write UDP packets from the UDP network connection established on file descriptor fd.
Udpread reads at most n bytes of packet body into data , stores the header in hdr, and returns the number of bytes stored in data.
Udpwrite writes the n bytes stored in data in a UDP packet with header hdr.
Note that the Udphdr frames the addresses as local and remote instead of source and destination. Thus the hdr filled in for a packet read by udpread can be used unchanged in udpwrite to send a response back to the sender of the original packet.

SOURCE
/usr/local/plan9/src/lib9/udp.c

SEE ALSO
ip(3)

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