1 #include <u.h>
2 #define NOPLAN9DEFINES
3 #include <libc.h>
4 #include <ip.h>
5 
6 #include <sys/socket.h>
7 #include <netinet/in.h>
8 
9 long
10 udpread(int fd, Udphdr *hdr, void *buf, long n)
11 {
12 	struct sockaddr_in sin;
13 	socklen_t len;
14 
15 	len = sizeof sin;
16 	if(getsockname(fd, (struct sockaddr*)&sin, &len) < 0)
17 		return -1;
18 	if(len != sizeof sin){
19 		werrstr("getsockname acting weird");
20 		return -1;
21 	}
22 	memset(hdr, 0, sizeof *hdr);
23 	memmove(hdr->laddr, v4prefix, IPaddrlen);
24 	memmove(hdr->laddr+12, &sin.sin_addr, sizeof(u32int));
25 	memmove(hdr->lport, &sin.sin_port, sizeof(u16int));
26 
27 	len = sizeof sin;
28 	n = recvfrom(fd, buf, n, 0, (struct sockaddr*)&sin, &len);
29 	if(n < 0)
30 		return -1;
31 	if(len != sizeof sin){
32 		werrstr("recvfrom acting weird");
33 		return -1;
34 	}
35 	memmove(hdr->raddr, v4prefix, IPaddrlen);
36 	memmove(hdr->raddr+12, &sin.sin_addr, sizeof(u32int));
37 	memmove(hdr->rport, &sin.sin_port, sizeof(u16int));
38 
39 	return n;
40 }
41 
42 long
43 udpwrite(int fd, Udphdr *hdr, void *buf, long n)
44 {
45 	struct sockaddr_in sin;
46 
47 	memset(&sin, 0, sizeof sin);
48 	sin.sin_family = AF_INET;
49 	memmove(&sin.sin_addr, hdr->raddr+12, 4);
50 	memmove(&sin.sin_port, hdr->rport, 2);
51 	return sendto(fd, buf, n, 0, (struct sockaddr*)&sin, sizeof sin);
52 }