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#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ip.h>
#include <ndb.h>
#include "ipconfig.h"
enum {
SOLICIT = 1,
ADVERTISE,
REQUEST,
CONFIRM,
RENEW,
REBIND,
REPLY,
RELEASE,
DECLINE,
RECONFIGURE,
INFOREQ,
RELAYFORW,
RELAYREPL,
};
static uchar v6dhcpservers[IPaddrlen] = {
0xff, 0x02, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 1, 0, 2,
};
static uchar sid[256];
static int sidlen;
static int
openlisten(void)
{
int n, fd, cfd;
char data[128], devdir[40];
sprint(data, "%s/udp!%I!546", conf.mpoint, conf.lladdr);
for (n = 0; (cfd = announce(data, devdir)) < 0; n++) {
if(!noconfig)
sysfatal("can't announce for dhcp: %r");
/* might be another client - wait and try again */
warning("can't announce %s: %r", data);
sleep(jitter());
if(n > 10)
return -1;
}
if(fprint(cfd, "headers") < 0)
sysfatal("can't set header mode: %r");
fprint(cfd, "ignoreadvice");
sprint(data, "%s/data", devdir);
fd = open(data, ORDWR);
if(fd < 0)
sysfatal("open %s: %r", data);
close(cfd);
return fd;
}
static int
transaction(int fd, int type, int timeout)
{
union {
Udphdr;
uchar buf[4096];
} ipkt, opkt;
uchar *p, *e, *x;
int tra, opt, len, sleepfor;
tra = lrand() & 0xFFFFFF;
ipmove(opkt.laddr, conf.lladdr);
ipmove(opkt.raddr, v6dhcpservers);
ipmove(opkt.ifcaddr, conf.lladdr);
hnputs(opkt.lport, 546);
hnputs(opkt.rport, 547);
p = opkt.buf + Udphdrsize;
*p++ = type;
*p++ = tra >> 16;
*p++ = tra >> 8;
*p++ = tra >> 0;
/* client identifier */
*p++ = 0x00; *p++ = 0x01;
/* len */
*p++ = conf.duidlen >> 8;
*p++ = conf.duidlen;
memmove(p, conf.duid, conf.duidlen);
p += conf.duidlen;
/* IA for non-temporary address */
len = 12;
if(validip(conf.laddr))
len += 4 + IPaddrlen + 2*4;
*p++ = 0x00; *p++ = 0x03;
*p++ = len >> 8;
*p++ = len;
/* IAID */
*p++ = 0x00; *p++ = 0x00; *p++ = 0x00; *p++ = 0x01;
/* T1, T2 */
*p++ = 0x00; *p++ = 0x00; *p++ = 0x00; *p++ = 0x00;
*p++ = 0x00; *p++ = 0x00; *p++ = 0x00; *p++ = 0x00;
if(len > 12){
*p++ = 0x00; *p++ = 0x05;
*p++ = 0x00; *p++ = IPaddrlen + 2*4;
memmove(p, conf.laddr, IPaddrlen);
p += IPaddrlen;
memset(p, 0xFF, 2*4);
p += 2*4;
}
/* Option Request */
*p++ = 0x00; *p++ = 0x06;
*p++ = 0x00; *p++ = 0x02;
*p++ = 0x00; *p++ = 0x17; /* DNS servers */
if(sidlen > 0){
*p++ = 0x00; *p++ = 0x02;
/* len */
*p++ = sidlen >> 8;
*p++ = sidlen;;
memmove(p, sid, sidlen);
p += sidlen;
}
len = -1;
for(sleepfor = 500; timeout > 0; sleepfor <<= 1){
DEBUG("sending dhcpv6 request %x", opkt.buf[Udphdrsize]);
alarm(sleepfor);
if(len < 0)
write(fd, opkt.buf, p - opkt.buf);
len = read(fd, ipkt.buf, sizeof(ipkt.buf));
timeout += alarm(0);
timeout -= sleepfor;
if(len == 0)
break;
if(len < Udphdrsize+4)
continue;
if(ipkt.buf[Udphdrsize+1] != ((tra>>16)&0xFF)
|| ipkt.buf[Udphdrsize+2] != ((tra>>8)&0xFF)
|| ipkt.buf[Udphdrsize+3] != ((tra>>0)&0xFF))
continue;
DEBUG("got dhcpv6 reply %x from %I on %I", ipkt.buf[Udphdrsize+0], ipkt.raddr, ipkt.ifcaddr);
type |= (int)ipkt.buf[Udphdrsize+0]<<8;
switch(type){
case ADVERTISE << 8 | SOLICIT:
case REPLY << 8 | REQUEST:
goto Response;
default:
return -1;
}
}
return -1;
Response:
for(p = ipkt.buf + Udphdrsize + 4, e = ipkt.buf + len; p < e; p = x) {
if (p+4 > e)
return -1;
opt = (int)p[0] << 8 | p[1];
len = (int)p[2] << 8 | p[3];
p += 4;
x = p+len;
if (x > e)
return -1;
DEBUG("got dhcpv6 option %x: [%d] %.*H", opt, len, len, p);
switch(opt){
case 0x01: /* client identifier */
continue;
case 0x02: /* server identifier */
if(len < 1 || len > sizeof(sid))
break;
sidlen = len;
memmove(sid, p, sidlen);
continue;
case 0x03: /* IA for non-temporary address */
if(p+12+4+IPaddrlen+2*4 > x)
break;
/* skip IAID, T1, T2 */
p += 12;
/* IA Addresss */
if(p[0] != 0x00 || p[1] != 0x05
|| p[2] != 0x00 || p[3] != IPaddrlen+2*4)
break;
p += 4;
memset(conf.mask, 0xFF, IPaddrlen);
memmove(conf.laddr, p, IPaddrlen);
continue;
case 0x17: /* dns servers */
if(len % IPaddrlen)
break;
addaddrs(conf.dns, sizeof(conf.dns), p, len);
continue;
default:
DEBUG("unknown dhcpv6 option %x", opt);
continue;
}
warning("dhcpv6: malformed option %x: [%d] %.*H", opt, len, len, x-len);
}
return 0;
}
void
dhcpv6query(void)
{
int fd;
fd = openlisten();
if(transaction(fd, SOLICIT, 5000) < 0)
goto out;
if(!validip(conf.laddr))
goto out;
if(transaction(fd, REQUEST, 10000) < 0)
goto out;
out:
close(fd);
}
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