tudp.c - plan9port - [fork] Plan 9 from user space
HTML git clone git://src.adamsgaard.dk/plan9port
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
---
tudp.c (1093B)
---
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 /*
10 * prefix of all v4 addresses
11 * copied from libip because libc cannot depend on libip
12 */
13 static uchar v4prefix[IPaddrlen] = {
14 0, 0, 0, 0,
15 0, 0, 0, 0,
16 0, 0, 0xff, 0xff,
17 0, 0, 0, 0
18 };
19
20 long
21 udpread(int fd, Udphdr *hdr, void *buf, long n)
22 {
23 struct sockaddr_in sin;
24 socklen_t len;
25
26 len = sizeof sin;
27 n = recvfrom(fd, buf, n, 0, (struct sockaddr*)&sin, &len);
28 if(len != sizeof sin){
29 werrstr("recvfrom acting weird");
30 return -1;
31 }
32 if(n < 0)
33 return -1;
34 memset(hdr, 0, sizeof *hdr);
35 memmove(hdr->raddr, v4prefix, IPaddrlen);
36 *(u32int*)(hdr->raddr+12) = *(u32int*)&sin.sin_addr;
37 *(u16int*)hdr->rport = *(u16int*)&sin.sin_port;
38 return n;
39 }
40
41 long
42 udpwrite(int fd, Udphdr *hdr, void *buf, long n)
43 {
44 struct sockaddr_in sin;
45
46 memset(&sin, 0, sizeof sin);
47 sin.sin_family = AF_INET;
48 *(u32int*)&sin.sin_addr = *(u32int*)(hdr->raddr+12);
49 *(u16int*)&sin.sin_port = *(u16int*)hdr->rport;
50 return sendto(fd, buf, n, 0, (struct sockaddr*)&sin, sizeof sin);
51 }