ref: c4603260f8736dbea8d7f47c46e8db0cf1a23fa0
dir: /sys/src/cmd/ip/ipconfig/ipv6.c/
/*
* ipconfig for IPv6
* RS means Router Solicitation
* RA means Router Advertisement
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ip.h>
#include "ipconfig.h"
#include "../icmp.h"
#pragma varargck argpos ralog 1
#define RALOG "v6routeradv"
#define NetS(x) (((uchar*)x)[0]<< 8 | ((uchar*)x)[1])
#define NetL(x) (((uchar*)x)[0]<<24 | ((uchar*)x)[1]<<16 | \
((uchar*)x)[2]<< 8 | ((uchar*)x)[3])
enum {
ICMP6LEN= 4,
};
typedef struct Hdr Hdr;
struct Hdr /* ICMP v4 & v6 header */
{
uchar type;
uchar code;
uchar cksum[2]; /* Checksum */
uchar data[];
};
char *icmpmsg6[Maxtype6+1] =
{
[EchoReply] "EchoReply",
[UnreachableV6] "UnreachableV6",
[PacketTooBigV6] "PacketTooBigV6",
[TimeExceedV6] "TimeExceedV6",
[Redirect] "Redirect",
[EchoRequest] "EchoRequest",
[TimeExceed] "TimeExceed",
[InParmProblem] "InParmProblem",
[Timestamp] "Timestamp",
[TimestampReply] "TimestampReply",
[InfoRequest] "InfoRequest",
[InfoReply] "InfoReply",
[AddrMaskRequest] "AddrMaskRequest",
[AddrMaskReply] "AddrMaskReply",
[EchoRequestV6] "EchoRequestV6",
[EchoReplyV6] "EchoReplyV6",
[RouterSolicit] "RouterSolicit",
[RouterAdvert] "RouterAdvert",
[NbrSolicit] "NbrSolicit",
[NbrAdvert] "NbrAdvert",
[RedirectV6] "RedirectV6",
};
static char *icmp6opts[] =
{
[0] "unknown option",
[V6nd_srclladdr] "srcll_addr",
[V6nd_targlladdr] "targll_addr",
[V6nd_pfxinfo] "prefix",
[V6nd_redirhdr] "redirect",
[V6nd_mtu] "mtu",
[V6nd_home] "home",
[V6nd_srcaddrs] "src_addrs",
[V6nd_ip] "ip",
[V6nd_rdns] "rdns",
[V6nd_9fs] "9fs",
[V6nd_9auth] "9auth",
};
uchar v6allroutersL[IPaddrlen] = {
0xff, 0x02, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0x02
};
uchar v6allnodesL[IPaddrlen] = {
0xff, 0x02, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0x01
};
uchar v6Unspecified[IPaddrlen] = {
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0
};
uchar v6loopback[IPaddrlen] = {
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 1
};
uchar v6glunicast[IPaddrlen] = {
0x08, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0
};
uchar v6linklocal[IPaddrlen] = {
0xfe, 0x80, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0
};
uchar v6solpfx[IPaddrlen] = {
0xff, 0x02, 0, 0,
0, 0, 0, 0,
0, 0, 0, 1,
/* last 3 bytes filled with low-order bytes of addr being solicited */
0xff, 0, 0, 0,
};
uchar v6defmask[IPaddrlen] = {
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0, 0, 0, 0,
0, 0, 0, 0
};
enum
{
Vadd,
Vremove,
Vunbind,
Vaddpref6,
Vra6,
};
static void
ralog(char *fmt, ...)
{
char msg[512];
va_list arg;
va_start(arg, fmt);
vseprint(msg, msg+sizeof msg, fmt, arg);
va_end(arg);
syslog(debug, RALOG, msg);
}
void
ea2lla(uchar *lla, uchar *ea)
{
assert(IPaddrlen == 16);
memset(lla, 0, IPaddrlen);
lla[0] = 0xFE;
lla[1] = 0x80;
lla[8] = ea[0] ^ 0x2;
lla[9] = ea[1];
lla[10] = ea[2];
lla[11] = 0xFF;
lla[12] = 0xFE;
lla[13] = ea[3];
lla[14] = ea[4];
lla[15] = ea[5];
}
void
ipv62smcast(uchar *smcast, uchar *a)
{
assert(IPaddrlen == 16);
memset(smcast, 0, IPaddrlen);
smcast[0] = 0xFF;
smcast[1] = 0x02;
smcast[11] = 0x1;
smcast[12] = 0xFF;
smcast[13] = a[13];
smcast[14] = a[14];
smcast[15] = a[15];
}
void
v6paraminit(Conf *cf)
{
cf->sendra = cf->recvra = 0;
cf->mflag = 0;
cf->oflag = 0;
cf->maxraint = Maxv6initraintvl;
cf->minraint = Maxv6initraintvl / 4;
cf->linkmtu = 1500;
cf->reachtime = V6reachabletime;
cf->rxmitra = V6retranstimer;
cf->ttl = MAXTTL;
cf->routerlt = 0;
cf->prefixlen = 64;
cf->onlink = 0;
cf->autoflag = 0;
cf->validlt = cf->preflt = ~0L;
}
static char *
optname(unsigned opt)
{
static char buf[32];
if(opt >= nelem(icmp6opts) || icmp6opts[opt] == nil) {
snprint(buf, sizeof buf, "unknown option %d", opt);
return buf;
} else
return icmp6opts[opt];
}
static char*
opt_seprint(uchar *ps, uchar *pe, char *sps, char *spe)
{
int otype, osz, pktlen;
uchar *a;
char *p = sps, *e = spe;
a = ps;
for (pktlen = pe - ps; pktlen > 0; pktlen -= osz) {
otype = a[0];
osz = a[1] * 8;
switch (otype) {
default:
return seprint(p, e, " option=%s ", optname(otype));
case V6nd_srclladdr:
case V6nd_targlladdr:
if(pktlen < osz || osz != 8)
return seprint(p, e, " option=%s bad size=%d",
optname(otype), osz);
p = seprint(p, e, " option=%s maddr=%E", optname(otype),
a+2);
break;
case V6nd_pfxinfo:
if(pktlen < osz || osz != 32)
return seprint(p, e, " option=%s: bad size=%d",
optname(otype), osz);
p = seprint(p, e, " option=%s pref=%I preflen=%3.3d"
" lflag=%1.1d aflag=%1.1d unused1=%1.1d"
" validlt=%ud preflt=%ud unused2=%1.1d",
optname(otype), a+16, (int)(*(a+2)),
(*(a+3) & (1 << 7)) != 0,
(*(a+3) & (1 << 6)) != 0,
(*(a+3) & 63) != 0,
NetL(a+4), NetL(a+8), NetL(a+12)!=0);
break;
}
a += osz;
}
return p;
}
static void
catch(void *a, char *msg)
{
USED(a);
if(strstr(msg, "alarm"))
noted(NCONT);
else
noted(NDFLT);
}
static int
dialicmpv6(uchar *ip, int port)
{
char addr[128], local[128];
int fd, cfd;
snprint(addr, sizeof(addr), "%s/icmpv6!%I!%d!r", conf.mpoint, ip, port);
snprint(local, sizeof(local), "%I!%d", conf.laddr, port);
if((fd = dial(addr, local, nil, &cfd)) < 0)
sysfatal("dialicmp6: %r");
fprint(cfd, "headers");
fprint(cfd, "ignoreadvice");
if(ISIPV6MCAST(ip))
fprint(cfd, "addmulti %I", conf.laddr);
close(cfd);
return fd;
}
static int
arpenter(uchar *ip, uchar *mac)
{
char buf[256];
int fd, n;
if(!validip(ip))
return 0;
snprint(buf, sizeof buf, "%s/arp", conf.mpoint);
if((fd = open(buf, OWRITE)) < 0){
warning("couldn't open %s: %r", buf);
return -1;
}
n = snprint(buf, sizeof buf, "add %s %I %E %I\n", conf.type, ip, mac, conf.laddr);
if(write(fd, buf, n) != n) {
warning("arpenter: %s: %r", buf);
close(fd);
return 0;
}
close(fd);
return 1;
}
static int
arpcheck(uchar *ip)
{
char buf[256], *f[5], *p;
uchar addr[IPaddrlen];
Biobuf *bp;
int rv;
snprint(buf, sizeof buf, "%s/arp", conf.mpoint);
bp = Bopen(buf, OREAD);
if(bp == nil){
warning("couldn't open %s: %r", buf);
return -1;
}
rv = 0;
while((p = Brdline(bp, '\n')) != nil){
p[Blinelen(bp)-1] = 0;
if(tokenize(p, f, nelem(f)) < 3)
continue;
if(parseip(addr, f[2]) != -1)
continue;
if(ipcmp(addr, ip) == 0){
rv = 1;
break;
}
}
Bterm(bp);
return rv;
}
static int
masklen(uchar *mask)
{
int len;
for(len=0; len < 128; len += 8){
if(*mask != 255)
break;
mask++;
}
while(len < 128 && (*mask & (0x80 >> (len & 7))) != 0)
len++;
return len;
}
static void
genipmkask(uchar *mask, int len)
{
memset(mask, 0, IPaddrlen);
if(len < 0)
len = 0;
else if(len > 128)
len = 128;
for(; len >= 8; len -= 8)
*mask++ = 255;
if(len > 0)
*mask = ~((1<<(8-len))-1);
}
/* add ipv6 addr to an interface */
int
ip6cfg(void)
{
int tentative, n;
char buf[256];
if(!validip(conf.laddr) || isv4(conf.laddr))
return -1;
tentative = dupl_disc;
Again:
if(tentative)
n = sprint(buf, "try");
else
n = sprint(buf, "add");
n += snprint(buf+n, sizeof buf-n, " %I", conf.laddr);
if(!validip(conf.mask))
ipmove(conf.mask, v6defmask);
n += snprint(buf+n, sizeof buf-n, " %M", conf.mask);
if(validip(conf.raddr)){
n += snprint(buf+n, sizeof buf-n, " %I", conf.raddr);
if(conf.mtu != 0)
n += snprint(buf+n, sizeof buf-n, " %d", conf.mtu);
}
if(write(conf.cfd, buf, n) < 0){
warning("write(%s): %r", buf);
return -1;
}
if(!tentative){
if(validip(conf.gaddr) && !isv4(conf.gaddr))
adddefroute(conf.gaddr, conf.laddr, conf.laddr, conf.mask);
return 0;
}
sleep(1000);
if(arpcheck(conf.laddr) <= 0) {
tentative = 0;
goto Again;
}
warning("found dup entry in arp cache");
doremove();
return 0;
}
static int
recvra6on(Ipifc *ifc)
{
if(ifc == nil)
return 0;
else if(ifc->sendra6 > 0)
return IsRouter;
else if(ifc->recvra6 > 0)
return IsHostRecv;
else
return IsHostNoRecv;
}
static int
findllip(uchar *ip, Ipifc *ifc)
{
Iplifc *lifc;
for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
if(ISIPV6LINKLOCAL(lifc->ip)){
ipmove(ip, lifc->ip);
return 1;
}
}
ipmove(ip, v6Unspecified);
return 0;
}
static void
sendrs(int fd, uchar *dst)
{
Routersol *rs;
Lladdropt *llao;
uchar buf[1024];
int pktlen;
memset(buf, 0, sizeof buf);
rs = (Routersol *)buf;
rs->type = ICMP6_RS;
ipmove(rs->dst, dst);
ipmove(rs->src, conf.laddr);
pktlen = sizeof *rs;
if(conf.hwalen > 0){
llao = (Lladdropt *)&buf[pktlen];
llao->type = V6nd_srclladdr;
llao->len = (2+7+conf.hwalen)/8;
memmove(llao->lladdr, conf.hwa, conf.hwalen);
pktlen += 8 * llao->len;
}
if(write(fd, rs, pktlen) != pktlen)
ralog("sendrs: write failed, pkt size %d", pktlen);
else
ralog("sendrs: sent solicitation to %I from %I on %s",
rs->dst, rs->src, conf.dev);
}
/*
* a router receiving a router adv from another
* router calls this; it is basically supposed to
* log the information in the ra and raise a flag
* if any parameter value is different from its configured values.
*
* doing nothing for now since I don't know where to log this yet.
*/
static void
recvrarouter(uchar buf[], int pktlen)
{
USED(buf, pktlen);
}
/* host receiving a router advertisement calls this */
static void
ewrite(int fd, char *str)
{
int n;
if(fd < 0)
return;
n = strlen(str);
if(write(fd, str, n) != n)
ralog("write(%s) failed: %r", str);
}
static void
issuebasera6(Conf *cf)
{
char *cfg;
cfg = smprint("ra6 mflag %d oflag %d reachtime %d rxmitra %d "
"ttl %d routerlt %d",
cf->mflag, cf->oflag, cf->reachtime, cf->rxmitra,
cf->ttl, cf->routerlt);
ewrite(cf->cfd, cfg);
free(cfg);
}
static void
issuerara6(Conf *cf)
{
char *cfg;
cfg = smprint("ra6 sendra %d recvra %d maxraint %d minraint %d "
"linkmtu %d",
cf->sendra, cf->recvra, cf->maxraint, cf->minraint,
cf->linkmtu);
ewrite(cf->cfd, cfg);
free(cfg);
}
static void
issueadd6(Conf *cf)
{
char *cfg;
cfg = smprint("add6 %I %d %d %d %lud %lud", cf->v6pref, cf->prefixlen,
cf->onlink, cf->autoflag, cf->validlt, cf->preflt);
ewrite(cf->cfd, cfg);
free(cfg);
}
static void
recvrahost(uchar buf[], int pktlen)
{
int m, n, optype;
uchar src[IPaddrlen];
Lladdropt *llao;
Mtuopt *mtuo;
Prefixopt *prfo;
Routeradv *ra;
static int first = 1;
m = sizeof *ra;
ra = (Routeradv*)buf;
if(pktlen < m)
return;
if(!ISIPV6LINKLOCAL(ra->src))
return;
conf.ttl = ra->cttl;
conf.mflag = (MFMASK & ra->mor);
conf.oflag = (OCMASK & ra->mor);
conf.routerlt = nhgets(ra->routerlt);
conf.reachtime = nhgetl(ra->rchbltime);
conf.rxmitra = nhgetl(ra->rxmtimer);
issuebasera6(&conf);
while(pktlen - m >= 8) {
n = m;
optype = buf[n];
m += 8 * buf[n+1];
if(pktlen < m)
return;
switch (optype) {
case V6nd_srclladdr:
llao = (Lladdropt *)&buf[n];
if(llao->len == 1 && conf.hwalen == 6)
arpenter(ra->src, llao->lladdr);
break;
case V6nd_mtu:
mtuo = (Mtuopt*)&buf[n];
conf.linkmtu = nhgetl(mtuo->mtu);
break;
case V6nd_pfxinfo:
prfo = (Prefixopt*)&buf[n];
if(prfo->len != 4) {
ralog("illegal len (%d) for prefix option", prfo->len);
return;
}
if((prfo->plen & 127) == 0
|| !validip(prfo->pref)
|| isv4(prfo->pref)
|| ipcmp(prfo->pref, v6loopback) == 0
|| ISIPV6MCAST(prfo->pref)
|| ISIPV6LINKLOCAL(prfo->pref)){
ralog("igoring bogus prefix from %I on %s; pfx %I /%d",
ra->src, conf.dev, prfo->pref, prfo->plen);
break;
}
if(first) {
first = 0;
ralog("got initial RA from %I on %s; pfx %I /%d",
ra->src, conf.dev, prfo->pref, prfo->plen);
}
conf.prefixlen = prfo->plen & 127;
genipmkask(conf.mask, conf.prefixlen);
maskip(prfo->pref, conf.mask, conf.v6pref);
conf.onlink = ((prfo->lar & OLMASK) != 0);
conf.autoflag = ((prfo->lar & AFMASK) != 0);
conf.validlt = nhgetl(prfo->validlt);
conf.preflt = nhgetl(prfo->preflt);
issueadd6(&conf);
if(conf.routerlt == 0)
break;
if((prfo->lar & RFMASK) != 0)
ipmove(conf.gaddr, prfo->pref);
else
ipmove(conf.gaddr, ra->src);
memmove(src, conf.v6pref, 8);
memmove(src+8, conf.laddr+8, 8);
adddefroute(conf.gaddr, conf.laddr, src, conf.mask);
break;
}
}
}
/*
* daemon to receive router advertisements from routers
*/
void
recvra6(void)
{
int fd, n, sendrscnt, recvracnt, sleepfor;
uchar buf[4096];
Ipifc *ifc;
ifc = readipifc(conf.mpoint, nil, myifc);
if(ifc == nil)
sysfatal("can't read ipifc: %r");
if(!findllip(conf.laddr, ifc))
sysfatal("no link local address");
fd = dialicmpv6(v6allnodesL, ICMP6_RA);
if(fd < 0)
sysfatal("can't open icmp_ra connection: %r");
notify(catch);
sendrscnt = Maxv6rss;
recvracnt = 0;
switch(rfork(RFPROC|RFMEM|RFFDG|RFNOWAIT|RFNOTEG)){
case -1:
sysfatal("can't fork: %r");
default:
close(fd);
return;
case 0:
break;
}
procsetname("recvra6 on %s %I", conf.dev, conf.laddr);
ralog("recvra6 on %s", conf.dev);
sleepfor = Minv6interradelay;
for (;;) {
alarm(sleepfor);
n = read(fd, buf, sizeof buf);
sleepfor = alarm(0);
/* wait for alarm to expire */
if(sendrscnt < 0 && sleepfor > 100)
continue;
ifc = readipifc(conf.mpoint, ifc, myifc);
if(ifc == nil) {
ralog("recvra6: can't read router params on %s, quitting on %s",
conf.mpoint, conf.dev);
exits(nil);
}
if(n <= 0) {
if(sendrscnt > 0) {
sendrscnt--;
if(recvra6on(ifc) == IsHostRecv)
sendrs(fd, v6allroutersL);
sleepfor = V6rsintvl + nrand(100);
}
if(sendrscnt == 0) {
sendrscnt--;
sleepfor = 0;
ralog("recvra6: no router advs after %d sols on %s",
Maxv6rss, conf.dev);
}
continue;
}
/* got at least initial ra; no whining */
sendrscnt = -1;
sleepfor = 0;
if(++recvracnt >= Maxv6initras){
recvracnt = 0;
sleepfor = Maxv6radelay;
}
switch (recvra6on(ifc)) {
case IsRouter:
recvrarouter(buf, n);
break;
case IsHostRecv:
recvrahost(buf, n);
break;
case IsHostNoRecv:
ralog("recvra6: recvra off, quitting on %s", conf.dev);
exits(nil);
}
}
}
/*
* return -1 -- error, reading/writing some file,
* 0 -- no arp table updates
* 1 -- successful arp table update
*/
int
recvrs(uchar *buf, int pktlen, uchar *sol)
{
int n;
Routersol *rs;
Lladdropt *llao;
n = sizeof *rs + sizeof *llao;
rs = (Routersol *)buf;
if(pktlen < n)
return 0;
llao = (Lladdropt *)&buf[sizeof *rs];
if(llao->type != V6nd_srclladdr || llao->len != 1 || conf.hwalen != 6)
return 0;
if(!validip(rs->src)
|| isv4(rs->src)
|| ipcmp(rs->src, v6loopback) == 0
|| ISIPV6MCAST(rs->src))
return 0;
if((n = arpenter(rs->src, llao->lladdr)) <= 0)
return n;
ipmove(sol, rs->src);
return 1;
}
void
sendra(int fd, uchar *dst, int rlt, Ipifc *ifc)
{
uchar buf[1024];
Iplifc *lifc;
Lladdropt *llao;
Prefixopt *prfo;
Routeradv *ra;
int pktlen;
memset(buf, 0, sizeof buf);
ra = (Routeradv *)buf;
ipmove(ra->dst, dst);
ipmove(ra->src, conf.laddr);
ra->type = ICMP6_RA;
ra->cttl = conf.ttl;
if(conf.mflag > 0)
ra->mor |= MFMASK;
if(conf.oflag > 0)
ra->mor |= OCMASK;
if(rlt > 0)
hnputs(ra->routerlt, conf.routerlt);
else
hnputs(ra->routerlt, 0);
hnputl(ra->rchbltime, conf.reachtime);
hnputl(ra->rxmtimer, conf.rxmitra);
pktlen = sizeof *ra;
/*
* include link layer address (mac address for now) in
* link layer address option
*/
if(conf.hwalen > 0){
llao = (Lladdropt *)&buf[pktlen];
llao->type = V6nd_srclladdr;
llao->len = (2+7+conf.hwalen)/8;
memmove(llao->lladdr, conf.hwa, conf.hwalen);
pktlen += 8 * llao->len;
}
/* include all global unicast prefixes on interface in prefix options */
for (lifc = (ifc != nil? ifc->lifc: nil); lifc != nil; lifc = lifc->next) {
if(pktlen > sizeof buf - 4*8)
break;
if(!validip(lifc->ip)
|| isv4(lifc->ip)
|| ipcmp(lifc->ip, v6loopback) == 0
|| ISIPV6MCAST(lifc->ip)
|| ISIPV6LINKLOCAL(lifc->ip))
continue;
prfo = (Prefixopt *)&buf[pktlen];
prfo->type = V6nd_pfxinfo;
prfo->len = 4;
prfo->plen = masklen(lifc->mask) & 127;
if(prfo->plen == 0)
continue;
ipmove(prfo->pref, lifc->net);
prfo->lar = AFMASK|OLMASK;
hnputl(prfo->validlt, lifc->validlt);
hnputl(prfo->preflt, lifc->preflt);
pktlen += 8 * prfo->len;
}
write(fd, buf, pktlen);
}
/*
* daemon to send router advertisements to hosts
*/
void
sendra6(void)
{
int fd, n, sleepfor, nquitmsgs;
uchar buf[4096], dst[IPaddrlen];
Ipifc *ifc;
ifc = readipifc(conf.mpoint, nil, myifc);
if(ifc == nil)
sysfatal("can't read ipifc: %r");
if(!findllip(conf.laddr, ifc))
sysfatal("no link local address");
fd = dialicmpv6(v6allroutersL, ICMP6_RS);
if(fd < 0)
sysfatal("can't open icmp_rs connection: %r");
notify(catch);
nquitmsgs = Maxv6finalras;
switch(rfork(RFPROC|RFMEM|RFFDG|RFNOWAIT|RFNOTEG)){
case -1:
sysfatal("can't fork: %r");
default:
close(fd);
return;
case 0:
break;
}
procsetname("sendra6 on %s %I", conf.dev, conf.laddr);
ralog("sendra6 on %s", conf.dev);
sleepfor = 100 + jitter();
for (;;) {
alarm(sleepfor);
n = read(fd, buf, sizeof buf);
sleepfor = alarm(0);
if(n > 0 && recvrs(buf, n, dst) > 0)
sendra(fd, dst, 1, ifc);
/* wait for alarm to expire */
if(sleepfor > 100)
continue;
sleepfor = Minv6interradelay;
ifc = readipifc(conf.mpoint, ifc, myifc);
if(ifc == nil) {
ralog("sendra6: can't read router params on %s, quitting on %s",
conf.mpoint, conf.dev);
exits(nil);
}
if(ifc->sendra6 <= 0){
if(nquitmsgs > 0) {
nquitmsgs--;
sendra(fd, v6allnodesL, 0, ifc);
continue;
} else {
ralog("sendra6: sendra off, quitting on %s", conf.dev);
exits(nil);
}
}
sendra(fd, v6allnodesL, 1, ifc);
sleepfor = randint(ifc->rp.minraint, ifc->rp.maxraint);
}
}
void
startra6(void)
{
static char routeon[] = "iprouting 1";
mklladdr();
if(conf.recvra > 0)
recvra6();
if(conf.sendra > 0) {
if(write(conf.cfd, routeon, sizeof routeon - 1) < 0) {
warning("write (iprouting 1) failed: %r");
return;
}
sendra6();
if(conf.recvra <= 0)
recvra6();
}
}
void
doipv6(int what)
{
fprint(conf.rfd, "tag ra6");
switch (what) {
default:
sysfatal("unknown IPv6 verb");
case Vaddpref6:
issueadd6(&conf);
break;
case Vra6:
issuebasera6(&conf);
issuerara6(&conf);
dolog = 1;
startra6();
break;
}
}