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