ref: bdd385803dcbccdf2750f7259a1784744541dec4
dir: /sys/src/cmd/ip/dhcpd/dhcpd.c/
#include <u.h>
#include <libc.h>
#include <ip.h>
#include <bio.h>
#include <ndb.h>
#include "dat.h"
/*
* ala rfc2131
*/
enum {
Maxloglen = 1024,
};
typedef struct Req Req;
struct Req
{
int fd; /* for reply */
Bootp *bp;
Udphdr *up;
Ipifc *ifc;
uchar *e; /* end of received message */
uchar *p; /* options pointer */
uchar *max; /* max end of reply */
/* expanded to v6 */
uchar ciaddr[IPaddrlen];
uchar giaddr[IPaddrlen];
/* parsed options */
int p9request; /* flag: this is a bootp with plan9 options */
int genrequest; /* flag: this is a bootp with generic options */
int dhcptype; /* dhcp message type */
int leasetime; /* dhcp lease */
uchar ip[IPaddrlen]; /* requested address */
uchar server[IPaddrlen]; /* server address */
char msg[ERRMAX]; /* error message */
char vci[32]; /* vendor class id */
char *id; /* client id */
uchar requested[32]; /* requested params */
uchar vendorclass[32];
char cputype[32-3];
Info gii; /* about target network */
Info ii; /* about target system */
int staticbinding;
uchar buf[2*1024]; /* message buffer */
};
char *blog = "ipboot";
char *homedir = "/";
char *mysysname;
Ipifc *ipifcs;
int debug;
int nobootp;
long now;
int slowstat, slowdyn;
char net[256];
int pptponly; /* only answer request that came from the pptp server */
int mute, mutestat;
int minlease = MinLease;
int staticlease = StaticLease;
static int v6opts;
/* option magic */
char plan9opt[4] = { 'p', '9', ' ', ' ' };
char genericopt[4] = { 0x63, 0x82, 0x53, 0x63 };
/* well known addresses */
uchar zeros[Maxhwlen];
/* option debug buffer */
char optbuf[1024];
char *op;
char *oe = optbuf + sizeof(optbuf);
char *optname[256] =
{
[OBend] "end",
[OBpad] "pad",
[OBmask] "mask",
[OBtimeoff] "timeoff",
[OBrouter] "router",
[OBtimeserver] "time",
[OBnameserver] "name",
[OBdnserver] "dns",
[OBlogserver] "log",
[OBcookieserver] "cookie",
[OBlprserver] "lpr",
[OBimpressserver] "impress",
[OBrlserver] "rl",
[OBhostname] "host",
[OBbflen] "bflen",
[OBdumpfile] "dumpfile",
[OBdomainname] "dom",
[OBrootserver] "rootserver",
[OBrootpath] "rootpath",
[OBextpath] "extpath",
[OBipforward] "ipforward",
[OBnonlocal] "nonlocal",
[OBpolicyfilter] "policyfilter",
[OBmaxdatagram] "maxdatagram",
[OBttl] "ttl",
[OBpathtimeout] "pathtimeout",
[OBpathplateau] "pathplateau",
[OBmtu] "mtu",
[OBsubnetslocal] "subnetslocal",
[OBbaddr] "baddr",
[OBdiscovermask] "discovermask",
[OBsupplymask] "supplymask",
[OBdiscoverrouter] "discoverrouter",
[OBrsserver] "rsserver",
[OBstaticroutes] "staticroutes",
[OBtrailerencap] "trailerencap",
[OBarptimeout] "arptimeout",
[OBetherencap] "etherencap",
[OBtcpttl] "tcpttl",
[OBtcpka] "tcpka",
[OBtcpkag] "tcpkag",
[OBnisdomain] "nisdomain",
[OBniserver] "niserver",
[OBntpserver] "ntpserver",
[OBvendorinfo] "vendorinfo",
[OBnetbiosns] "NBns",
[OBnetbiosdds] "NBdds",
[OBnetbiostype] "NBtype",
[OBnetbiosscope] "NBscope",
[OBxfontserver] "xfont",
[OBxdispmanager] "xdisp",
[OBnisplusdomain] "NPdomain",
[OBnisplusserver] "NP",
[OBhomeagent] "homeagent",
[OBsmtpserver] "smtp",
[OBpop3server] "pop3",
[OBnntpserver] "nntp",
[OBwwwserver] "www",
[OBfingerserver] "finger",
[OBircserver] "ircserver",
[OBstserver] "stserver",
[OBstdaserver] "stdaserver",
/* dhcp options */
[ODipaddr] "ip",
[ODlease] "leas",
[ODoverload] "overload",
[ODtype] "typ",
[ODserverid] "sid",
[ODparams] "params",
[ODmessage] "message",
[ODmaxmsg] "maxmsg",
[ODrenewaltime] "renewaltime",
[ODrebindingtime] "rebindingtime",
[ODvendorclass] "vendorclass",
[ODclientid] "cid",
[ODtftpserver] "tftpserver",
[ODbootfile] "bf",
[ODdnsdomain] "dnsdomain",
};
void addropt(Req*, int, uchar*);
void addrsopt(Req*, int, uchar**, int);
void arpenter(uchar*, uchar*, uchar*);
void bootp(Req*);
void byteopt(Req*, int, uchar);
void dhcp(Req*);
void hexopt(Req*, int, char*);
void logdhcp(Req*);
void logdhcpout(Req *, char *);
void longopt(Req*, int, long);
void maskopt(Req*, int, uchar*);
void miscoptions(Req*, uchar*);
int openlisten(char *net);
void p9addrsopt(Req *rp, int t, uchar **ip, int i);
void dnsnamesopt(Req *rp, int t, char *attr, Ndbtuple *nt);
void parseoptions(Req*);
void proto(Req*, int);
void rcvdecline(Req*);
void rcvdiscover(Req*);
void rcvinform(Req*);
void rcvrelease(Req*);
void rcvrequest(Req*);
int readlast(int, uchar*, int);
char* readsysname(void);
void remrequested(Req*, int);
void sendack(Req*, uchar*, int, int);
void sendnak(Req*, uchar*, char*);
void sendoffer(Req*, uchar*, int);
void stringopt(Req*, int, char*);
void termopt(Req*);
int validip(uchar*);
void vectoropt(Req*, int, uchar*, int);
void
usage(void)
{
fprint(2, "usage: dhcp [-dmnprsSZ] [-h homedir] [-f ndbfile] [-M minlease] "
"[-x netmtpt] [-Z staticlease] addr n [addr n] ...\n");
exits("usage");
}
void
main(int argc, char **argv)
{
int i, n, fd;
uchar ip[IPaddrlen];
Req r;
setnetmtpt(net, sizeof net, nil);
fmtinstall('E', eipfmt);
fmtinstall('I', eipfmt);
fmtinstall('V', eipfmt);
fmtinstall('M', eipfmt);
fmtinstall('H', encodefmt);
ARGBEGIN {
case '6':
v6opts = 1;
break;
case 'd':
debug = 1;
break;
case 'f':
ndbfile = EARGF(usage());
break;
case 'h':
homedir = EARGF(usage());
break;
case 'm':
mute = 1;
break;
case 'M':
minlease = atoi(EARGF(usage()));
if(minlease <= 0)
minlease = MinLease;
break;
case 'n':
nobootp = 1;
break;
case 'p':
pptponly = 1;
break;
case 'r':
mutestat = 1;
break;
case 's':
slowstat = 1;
break;
case 'S':
slowdyn = 1;
break;
case 'x':
setnetmtpt(net, sizeof net, EARGF(usage()));
break;
case 'Z':
staticlease = atoi(EARGF(usage()));
if(staticlease <= 0)
staticlease = StaticLease;
break;
default:
usage();
break;
} ARGEND;
while(argc > 1){
if(parseip(ip, argv[0]) == -1 || !validip(ip))
usage();
n = atoi(argv[1]);
if(n <= 0)
usage();
initbinding(ip, n);
argc -= 2;
argv += 2;
}
/* for debugging */
for(i = 0; i < 256; i++)
if(optname[i] == 0)
optname[i] = smprint("%d", i);
/* what is my name? */
mysysname = readsysname();
/* put process in background */
if(!debug)
switch(rfork(RFNOTEG|RFPROC|RFFDG)) {
case -1:
fatal("fork: %r");
case 0:
break;
default:
exits(0);
}
if (chdir(homedir) < 0)
warning("can't change to directory %s: %r", homedir);
fd = openlisten(net);
for(;;){
memset(&r, 0, sizeof(r));
r.fd = fd;
n = readlast(r.fd, r.buf, sizeof(r.buf));
if(n < Udphdrsize)
fatal("error reading requests: %r");
op = optbuf;
*op = 0;
proto(&r, n);
}
}
void
proto(Req *rp, int n)
{
now = time(0);
rp->e = rp->buf + n;
rp->bp = (Bootp*)rp->buf;
rp->up = (Udphdr*)rp->buf;
rp->max = rp->buf + Udphdrsize + MINSUPPORTED - IPUDPHDRSIZE;
rp->p = rp->bp->optdata;
v4tov6(rp->giaddr, rp->bp->giaddr);
v4tov6(rp->ciaddr, rp->bp->ciaddr);
if(pptponly && rp->bp->htype != 0)
return;
if(rp->bp->op != Bootrequest){
warning("not bootrequest");
return;
}
if(!isv4(rp->up->laddr))
return;
ipifcs = readipifc(net, ipifcs, -1);
if((rp->ifc = findifc(rp->up->ifcaddr)) == nil){
warning("no interface");
return;
}
if(validip(rp->giaddr)){
/* info about gateway */
if(lookupip(rp->giaddr, nil, nil, &rp->gii, 1) < 0){
warning("unknown gateway %I", rp->giaddr);
return;
}
rp->gii.ifc = nil;
} else {
/* no gateway, directly connected */
if(ipcmp(rp->up->laddr, IPv4bcast) != 0
&& ipremoteonifc(rp->ifc, rp->up->laddr) == nil){
warning("wrong network %I->%I on %s",
rp->up->raddr, rp->up->laddr, rp->ifc->dev);
return;
}
memset(&rp->gii, 0, sizeof(rp->gii));
rp->gii.ifc = rp->ifc;
}
if(rp->e < (uchar*)rp->bp->sname){
warning("packet too short");
return;
}
if(rp->e >= rp->bp->optdata){
if(memcmp(rp->bp->optmagic, plan9opt, sizeof(rp->bp->optmagic)) == 0)
rp->p9request = 1;
if(memcmp(rp->bp->optmagic, genericopt, sizeof(rp->bp->optmagic)) == 0) {
rp->genrequest = 1;
parseoptions(rp);
}
}
rp->p = rp->bp->optdata;
/* If no id is specified, make one from the hardware address
* of the target. We assume all zeros is not a hardware address
* which could be a mistake.
*/
if(rp->id == nil){
static char hwaid[Maxstr];
if(rp->bp->hlen > Maxhwlen || memcmp(zeros, rp->bp->chaddr, rp->bp->hlen) == 0){
warning("no chaddr");
return;
}
snprint(hwaid, sizeof(hwaid), "hwa%2.2ux_%.*lH", rp->bp->htype, rp->bp->hlen, rp->bp->chaddr);
rp->id = hwaid;
}
/* info about target system */
if(lookup(rp->bp, &rp->ii, &rp->gii) == 0)
if(rp->ii.indb)
rp->staticbinding = 1;
if(rp->dhcptype)
dhcp(rp);
else
bootp(rp);
}
static void
slowdelay(Req *rp)
{
if(slowstat && rp->staticbinding || slowdyn && !rp->staticbinding)
sleep(2000);
}
void
dhcp(Req *rp)
{
logdhcp(rp);
switch(rp->dhcptype){
case Discover:
slowdelay(rp);
rcvdiscover(rp);
break;
case Request:
rcvrequest(rp);
break;
case Decline:
rcvdecline(rp);
break;
case Release:
rcvrelease(rp);
break;
case Inform:
rcvinform(rp);
break;
}
}
void
rcvdiscover(Req *rp)
{
Binding *b, *nb;
if(rp->staticbinding){
sendoffer(rp, rp->ii.ipaddr, (staticlease > minlease? staticlease: minlease));
return;
}
/*
* first look for an outstanding offer
*/
b = idtooffer(rp->id, &rp->gii);
/*
* rfc2131 says:
* If an address is available, the new address
* SHOULD be chosen as follows:
*
* o The client's current address as recorded in the client's current
* binding, ELSE
*
* o The client's previous address as recorded in the client's (now
* expired or released) binding, if that address is in the server's
* pool of available addresses and not already allocated, ELSE
*
* o The address requested in the 'Requested IP Address' option, if that
* address is valid and not already allocated, ELSE
*
* o A new address allocated from the server's pool of available
* addresses; the address is selected based on the subnet from which
* the message was received (if 'giaddr' is 0) or on the address of
* the relay agent that forwarded the message ('giaddr' when not 0).
*/
if(b == nil){
b = idtobinding(rp->id, &rp->gii, 1);
if(b && b->boundto && strcmp(b->boundto, rp->id) != 0)
if(validip(rp->ip) && samenet(rp->ip, &rp->gii)){
nb = iptobinding(rp->ip, 0);
if(nb && nb->lease < now)
b = nb;
}
}
if(b == nil){
warning("!Discover(%s via %I on %s): no binding %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
return;
}
mkoffer(b, rp->id, rp->leasetime);
sendoffer(rp, b->ip, b->offer);
}
void
rcvrequest(Req *rp)
{
Binding *b;
if(validip(rp->server)){
/* this is a reply to an offer - SELECTING */
/* check for hard assignment */
if(rp->staticbinding){
if(findifc(rp->server) != rp->ifc) {
warning("!Request(%s via %I on %s): for server %I not me",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->server);
} else
sendack(rp, rp->ii.ipaddr,
(staticlease > minlease? staticlease:
minlease), 1);
return;
}
b = idtooffer(rp->id, &rp->gii);
/* if we don't have an offer, nak */
if(b == nil){
warning("!Request(%s via %I on %s): no offer",
rp->id, rp->gii.ipaddr, rp->ifc->dev);
if(findifc(rp->server) == rp->ifc)
sendnak(rp, rp->server, "no offer for you");
return;
}
/* if not for me, retract offer */
if(findifc(rp->server) != rp->ifc){
b->expoffer = 0;
warning("!Request(%s via %I on %s): for server %I not me",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->server);
return;
}
/*
* if the client is confused about what we offered, nak.
* client really shouldn't be specifying this when selecting
*/
if(validip(rp->ip) && ipcmp(rp->ip, b->ip) != 0){
warning("!Request(%s via %I on %s): requests %I, not %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip, b->ip);
sendnak(rp, rp->ip, "bad ip address option");
return;
}
if(commitbinding(b) < 0){
warning("!Request(%s via %I on %s): can't commit %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, b->ip);
sendnak(rp, b->ip, "can't commit binding");
return;
}
sendack(rp, b->ip, b->offer, 1);
} else if(validip(rp->ip)){
/*
* checking address/net - INIT-REBOOT
*
* This is a rebooting client that remembers its old
* address.
*/
/* check for hard assignment */
if(rp->staticbinding){
if(ipcmp(rp->ip, rp->ii.ipaddr) != 0){
warning("!Request(%s via %I on %s): %I not valid for %E",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip, rp->bp->chaddr);
sendnak(rp, rp->ip, "not valid");
} else
sendack(rp, rp->ip, (staticlease > minlease?
staticlease: minlease), 1);
return;
}
/* make sure the network makes sense */
if(!samenet(rp->ip, &rp->gii)){
warning("!Request(%s via %I on %s): bad forward of %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
return;
}
b = iptobinding(rp->ip, 0);
if(b == nil){
warning("!Request(%s via %I on %s): no binding for %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
return;
}
if(ipcmp(rp->ip, b->ip) != 0 || now > b->lease){
warning("!Request(%s via %I on %s): %I not valid",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
sendnak(rp, rp->ip, "not valid");
return;
}
b->offer = b->lease - now;
sendack(rp, b->ip, b->offer, 1);
} else if(validip(rp->ciaddr)){
/*
* checking address - RENEWING or REBINDING
*
* these states are indistinguishable in our action. The only
* difference is how close to lease expiration the client is.
* If it is really close, it broadcasts the request hoping that
* some server will answer.
*/
/* check for hard assignment */
if(rp->staticbinding){
if(ipcmp(rp->ciaddr, rp->ii.ipaddr) != 0){
warning("!Request(%s via %I on %s): %I not valid",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ciaddr);
sendnak(rp, rp->ciaddr, "not valid");
} else
sendack(rp, rp->ciaddr, (staticlease > minlease?
staticlease: minlease), 1);
return;
}
/* make sure the network makes sense */
if(!samenet(rp->ciaddr, &rp->gii)){
warning("!Request(%s via %I on %s): bad forward of %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ciaddr);
return;
}
b = iptobinding(rp->ciaddr, 0);
if(b == nil){
warning("!Request(%s via %I on %s): no binding for %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ciaddr);
return;
}
if(ipcmp(rp->ciaddr, b->ip) != 0){
warning("!Request(%s via %I on %s): %I not valid",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ciaddr);
sendnak(rp, rp->ciaddr, "invalid ip address");
return;
}
mkoffer(b, rp->id, rp->leasetime);
if(commitbinding(b) < 0){
warning("!Request(%s via %I on %s): can't commit %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, b->ip);
sendnak(rp, b->ip, "can't commit binding");
return;
}
sendack(rp, b->ip, b->offer, 1);
}
}
void
rcvdecline(Req *rp)
{
Binding *b;
char buf[64];
if(rp->staticbinding)
return;
b = idtooffer(rp->id, &rp->gii);
if(b == nil){
warning("!Decline(%s via %I on %s): no binding",
rp->id, rp->gii.ipaddr, rp->ifc->dev);
return;
}
/* mark ip address as in use */
snprint(buf, sizeof(buf), "declined by %s", rp->id);
mkoffer(b, buf, 0x7fffffff);
commitbinding(b);
}
void
rcvrelease(Req *rp)
{
Binding *b;
if(rp->staticbinding)
return;
b = idtobinding(rp->id, &rp->gii, 0);
if(b == nil){
warning("!Release(%s via %I on %s): no binding",
rp->id, rp->gii.ipaddr, rp->ifc->dev);
return;
}
if(strcmp(rp->id, b->boundto) != 0){
warning("!Release(%s via %I on %s): invalid release of %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
return;
}
warning("Release(%s via %I on %s): releasing %I",
b->boundto, rp->gii.ipaddr, rp->ifc->dev, b->ip);
if(releasebinding(b, rp->id) < 0)
warning("release: couldn't release");
}
void
rcvinform(Req *rp)
{
Binding *b;
if(rp->staticbinding){
sendack(rp, rp->ii.ipaddr, 0, 0);
return;
}
b = iptobinding(rp->ciaddr, 0);
if(b == nil){
warning("!Inform(%s via %I on %s): no binding for %I",
rp->id, rp->gii.ipaddr, rp->ifc->dev, rp->ip);
return;
}
sendack(rp, b->ip, 0, 0);
}
int
setsiaddr(uchar *siaddr, uchar *saddr, uchar *laddr)
{
if(ipcmp(saddr, IPnoaddr) != 0){
v6tov4(siaddr, saddr);
return 0;
} else {
v6tov4(siaddr, laddr);
return 1;
}
}
int
ismuted(Req *rp)
{
return mute || (mutestat && rp->staticbinding);
}
void
sendoffer(Req *rp, uchar *ip, int offer)
{
int n;
ushort flags;
Bootp *bp;
Udphdr *up;
bp = rp->bp;
up = rp->up;
flags = nhgets(bp->flags);
if(validip(rp->giaddr)){
ipmove(up->raddr, rp->giaddr);
hnputs(up->rport, 67);
} else {
localip(up->laddr, ip, rp->ifc);
if(flags & Fbroadcast){
ipmove(up->raddr, IPv4bcast);
hnputs(up->rport, 68);
} else {
ipmove(up->raddr, ip);
if(bp->htype == 1)
arpenter(up->raddr, bp->chaddr, up->laddr);
hnputs(up->rport, 68);
}
}
/*
* fill in standard bootp part
*/
bp->op = Bootreply;
bp->hops = 0;
hnputs(bp->secs, 0);
memset(bp->ciaddr, 0, sizeof(bp->ciaddr));
v6tov4(bp->giaddr, rp->giaddr);
v6tov4(bp->yiaddr, ip);
setsiaddr(bp->siaddr, rp->ii.tftp, up->laddr);
strncpy(bp->sname, mysysname, sizeof(bp->sname));
strncpy(bp->file, rp->ii.bootf, sizeof(bp->file));
/*
* set options
*/
byteopt(rp, ODtype, Offer);
longopt(rp, ODlease, offer);
addropt(rp, ODserverid, up->laddr);
miscoptions(rp, ip);
termopt(rp);
logdhcpout(rp, "Offer");
/*
* send
*/
n = rp->p - rp->buf;
if(!ismuted(rp) && write(rp->fd, rp->buf, n) != n)
warning("offer: write failed: %r");
}
void
sendack(Req *rp, uchar *ip, int offer, int sendlease)
{
int n;
ushort flags;
Bootp *bp;
Udphdr *up;
bp = rp->bp;
up = rp->up;
flags = nhgets(bp->flags);
if(validip(rp->giaddr)){
ipmove(up->raddr, rp->giaddr);
hnputs(up->rport, 67);
} else {
localip(up->laddr, ip, rp->ifc);
if(flags & Fbroadcast){
ipmove(up->raddr, IPv4bcast);
hnputs(up->rport, 68);
} else {
ipmove(up->raddr, ip);
if(bp->htype == 1)
arpenter(up->raddr, bp->chaddr, up->laddr);
hnputs(up->rport, 68);
}
}
/*
* fill in standard bootp part
*/
bp->op = Bootreply;
bp->hops = 0;
hnputs(bp->secs, 0);
v6tov4(bp->giaddr, rp->giaddr);
v6tov4(bp->yiaddr, ip);
setsiaddr(bp->siaddr, rp->ii.tftp, up->laddr);
strncpy(bp->sname, mysysname, sizeof(bp->sname));
strncpy(bp->file, rp->ii.bootf, sizeof(bp->file));
/*
* set options
*/
byteopt(rp, ODtype, Ack);
if(sendlease){
longopt(rp, ODlease, offer);
}
addropt(rp, ODserverid, up->laddr);
miscoptions(rp, ip);
termopt(rp);
logdhcpout(rp, "Ack");
/*
* send
*/
n = rp->p - rp->buf;
if(!ismuted(rp) && write(rp->fd, rp->buf, n) != n)
warning("ack: write failed: %r");
}
void
sendnak(Req *rp, uchar *ip, char *msg)
{
int n;
Bootp *bp;
Udphdr *up;
bp = rp->bp;
up = rp->up;
/*
* set destination (always broadcast)
*/
if(validip(rp->giaddr)){
ipmove(up->raddr, rp->giaddr);
hnputs(up->rport, 67);
} else {
localip(up->laddr, ip, rp->ifc);
ipmove(up->raddr, IPv4bcast);
hnputs(up->rport, 68);
}
/*
* fill in standard bootp part
*/
bp->op = Bootreply;
bp->hops = 0;
hnputs(bp->secs, 0);
v6tov4(bp->giaddr, rp->giaddr);
memset(bp->ciaddr, 0, sizeof(bp->ciaddr));
memset(bp->yiaddr, 0, sizeof(bp->yiaddr));
memset(bp->siaddr, 0, sizeof(bp->siaddr));
/*
* set options
*/
byteopt(rp, ODtype, Nak);
addropt(rp, ODserverid, up->laddr);
if(msg)
stringopt(rp, ODmessage, msg);
if(strncmp(rp->id, "id", 2) == 0)
hexopt(rp, ODclientid, rp->id+2);
termopt(rp);
logdhcpout(rp, "Nak");
/*
* send nak
*/
n = rp->p - rp->buf;
if(!ismuted(rp) && write(rp->fd, rp->buf, n) != n)
warning("nak: write failed: %r");
}
void
bootp(Req *rp)
{
int n;
Bootp *bp;
Udphdr *up;
ushort flags;
Info *iip;
warning("bootp %s %I->%I from %s via %I on %s, file %s",
rp->genrequest? "generic": (rp->p9request? "p9": ""),
rp->up->raddr, rp->up->laddr,
rp->id, rp->gii.ipaddr, rp->ifc->dev,
rp->bp->file);
if(nobootp)
return;
bp = rp->bp;
up = rp->up;
iip = &rp->ii;
if(rp->staticbinding == 0){
warning("bootp from unknown %s via %I on %s",
rp->id, rp->gii.ipaddr, rp->ifc->dev);
return;
}
/* ignore if not for us */
if(*bp->sname){
if(strcmp(bp->sname, mysysname) != 0){
bp->sname[20] = 0;
warning("bootp for server %s", bp->sname);
return;
}
} else
slowdelay(rp);
/* ignore file for sgi arcs command bootp(); */
if(strcmp(bp->file, ";") == 0)
*bp->file = 0;
/* ignore if we don't know what file to load */
if(*bp->file == 0){
if(rp->genrequest && *iip->bootf2) /* if not plan 9 & have alternate file... */
strncpy(bp->file, iip->bootf2, sizeof(bp->file));
else if(*iip->bootf)
strncpy(bp->file, iip->bootf, sizeof(bp->file));
else if(*bp->sname) /* if we were asked, respond no matter what */
bp->file[0] = '\0';
else {
warning("no bootfile for %I", iip->ipaddr);
return;
}
}
/* ignore if the file is unreadable */
if(!rp->genrequest && bp->file[0] && access(bp->file, 4) < 0){
warning("inaccessible bootfile1 %s", bp->file);
return;
}
bp->op = Bootreply;
v6tov4(bp->yiaddr, iip->ipaddr);
if(rp->p9request){
warning("p9bootp: %I", iip->ipaddr);
memmove(bp->optmagic, plan9opt, 4);
rp->p += sprint((char*)rp->p, "%V %I %I %I",
iip->ipmask+IPv4off, iip->fsip, iip->auip, iip->gwip);
sprint(optbuf, "%s", (char*)(bp->optmagic));
} else if(rp->genrequest){
warning("genericbootp: %I", iip->ipaddr);
memmove(bp->optmagic, genericopt, 4);
miscoptions(rp, iip->ipaddr);
termopt(rp);
} else if(iip->vendor[0] != 0) {
warning("bootp vendor field: %s", iip->vendor);
memset(rp->p, 0, 128-4);
rp->p += sprint((char*)bp->optmagic, "%s", iip->vendor);
} else {
memset(rp->p, 0, 128-4);
rp->p += 128-4;
}
flags = nhgets(bp->flags);
if(validip(rp->giaddr)){
ipmove(up->raddr, rp->giaddr);
hnputs(up->rport, 67);
} else {
localip(up->laddr, iip->ipaddr, rp->ifc);
if(flags & Fbroadcast){
ipmove(up->raddr, IPv4bcast);
hnputs(up->rport, 68);
} else {
v4tov6(up->raddr, bp->yiaddr);
if(bp->htype == 1)
arpenter(up->raddr, bp->chaddr, up->laddr);
hnputs(up->rport, 68);
}
}
/*
* our identity
*/
strncpy(bp->sname, mysysname, sizeof(bp->sname));
/*
* set tftp server
*/
setsiaddr(bp->siaddr, iip->tftp, up->laddr);
if(rp->genrequest && *iip->bootf2)
setsiaddr(bp->siaddr, iip->tftp2, up->laddr);
/*
* RFC 1048 says that we must pad vendor field with
* zeros until we have a 64 byte field.
*/
n = rp->p - rp->bp->optdata;
if(n < 64-4) {
memset(rp->p, 0, (64-4)-n);
rp->p += (64-4)-n;
}
/*
* send
*/
n = rp->p - rp->buf;
if(!ismuted(rp) && write(rp->fd, rp->buf, n) != n)
warning("bootp: write failed: %r");
warning("bootp via %I: file %s xid(%ux)flag(%ux)ci(%V)gi(%V)yi(%V)si(%V) %s",
up->raddr, bp->file, nhgetl(bp->xid), nhgets(bp->flags),
bp->ciaddr, bp->giaddr, bp->yiaddr, bp->siaddr,
optbuf);
}
void
parseoptions(Req *rp)
{
int n, c, code;
uchar *o, *p;
p = rp->p;
while(p < rp->e){
code = *p++;
if(code == 255)
break;
if(code == 0)
continue;
/* ignore anything that's too long */
n = *p++;
o = p;
p += n;
if(p > rp->e)
return;
switch(code){
case ODipaddr: /* requested ip address */
if(n == IPv4addrlen)
v4tov6(rp->ip, o);
break;
case ODlease: /* requested lease time */
rp->leasetime = nhgetl(o);
if(rp->leasetime > MaxLease || rp->leasetime < 0)
rp->leasetime = MaxLease;
break;
case ODtype:
c = *o;
if(c < 10 && c > 0)
rp->dhcptype = c;
break;
case ODserverid:
if(n == IPv4addrlen)
v4tov6(rp->server, o);
break;
case ODmessage:
if(n > sizeof(rp->msg)-1)
n = sizeof(rp->msg)-1;
memmove(rp->msg, o, n);
rp->msg[n] = 0;
break;
case ODmaxmsg:
if(n < 2)
break;
c = nhgets(o);
c -= IPUDPHDRSIZE;
if(c <= 0)
break;
c += Udphdrsize;
if(c > sizeof(rp->buf))
c = sizeof(rp->buf);
rp->max = rp->buf + c;
break;
case ODclientid:
if(n <= 1)
break;
rp->id = toid(o, n);
break;
case ODparams:
if(n > sizeof(rp->requested))
n = sizeof(rp->requested);
memmove(rp->requested, o, n);
break;
case ODvendorclass:
if(n >= sizeof(rp->vendorclass))
n = sizeof(rp->vendorclass)-1;
memmove(rp->vendorclass, o, n);
rp->vendorclass[n] = 0;
if(strncmp((char*)rp->vendorclass, "p9-", 3) == 0)
strncpy(rp->cputype, (char*)rp->vendorclass+3, sizeof(rp->cputype));
break;
case OBend:
return;
}
}
}
void
remrequested(Req *rp, int opt)
{
uchar *p;
p = memchr(rp->requested, opt, sizeof(rp->requested));
if(p != nil)
*p = OBpad;
}
void
miscoptions(Req *rp, uchar *ip)
{
int i, j, na;
uchar *addrs[8];
uchar *op, *omax;
uchar x[nelem(addrs)*IPaddrlen], vopts[Maxoptlen];
char ip4str[16], *p, *attr[100], **a;
Ndbtuple *t;
Iplifc *lifc;
for(i=0; i<nelem(addrs); i++)
addrs[i] = &x[i*IPaddrlen];
/* always supply these */
if(validip(rp->ii.ipmask))
maskopt(rp, OBmask, rp->ii.ipmask);
else if(validip(rp->gii.ipmask))
maskopt(rp, OBmask, rp->gii.ipmask);
else if((lifc = ipremoteonifc(rp->ifc, ip)) != nil)
maskopt(rp, OBmask, lifc->mask);
if(validip(rp->ii.gwip)){
remrequested(rp, OBrouter);
addropt(rp, OBrouter, rp->ii.gwip);
} else if(validip(rp->gii.gwip)){
remrequested(rp, OBrouter);
addropt(rp, OBrouter, rp->gii.gwip);
} else if(validip(rp->giaddr)){
remrequested(rp, OBrouter);
addropt(rp, OBrouter, rp->giaddr);
}
/*
* OBhostname for the HP4000M switches
* (this causes NT to log infinite errors - tough shit)
*/
if(*rp->ii.domain){
remrequested(rp, OBhostname);
stringopt(rp, OBhostname, rp->ii.domain);
}
if(*rp->ii.rootpath)
stringopt(rp, OBrootpath, rp->ii.rootpath);
/* figure out what we need to lookup */
na = 0;
a = attr;
if(*rp->ii.domain == 0)
a[na++] = "dom";
a[na++] = "dnsdomain";
for(i = 0; i < sizeof(rp->requested); i++)
switch(rp->requested[i]){
case OBrouter:
a[na++] = "@ipgw";
break;
case OBdnserver:
a[na++] = "@dns";
break;
case OBnetbiosns:
a[na++] = "@wins";
break;
case OBrootserver:
a[na++] = "@rootserver";
break;
case OBsmtpserver:
a[na++] = "@smtp";
break;
case OBpop3server:
a[na++] = "@pop3";
break;
case OBwwwserver:
a[na++] = "@www";
break;
case OBntpserver:
a[na++] = "@ntp";
break;
case OBtimeserver:
a[na++] = "@time";
break;
}
if(strncmp((char*)rp->vendorclass, "plan9_", 6) == 0
|| strncmp((char*)rp->vendorclass, "p9-", 3) == 0){
a[na++] = "@fs";
a[na++] = "@auth";
}
t = lookupinfo(ip, a, na);
/* lookup anything we might be missing */
if(*rp->ii.domain == 0)
lookupname(rp->ii.domain, sizeof(rp->ii.domain), t);
/* add any requested ones that we know about */
for(i = 0; i < sizeof(rp->requested); i++)
switch(rp->requested[i]){
case OBrouter:
j = lookupserver("ipgw", addrs, nelem(addrs), t);
addrsopt(rp, OBrouter, addrs, j);
break;
case OBdnserver:
j = lookupserver("dns", addrs, nelem(addrs), t);
addrsopt(rp, OBdnserver, addrs, j);
break;
case OBhostname:
if(*rp->ii.domain)
stringopt(rp, OBhostname, rp->ii.domain);
break;
case OBdomainname:
p = strchr(rp->ii.domain, '.');
if(p != nil)
stringopt(rp, OBdomainname, p+1);
break;
case ODdnsdomain:
dnsnamesopt(rp, ODdnsdomain, "dnsdomain", t);
break;
case OBnetbiosns:
j = lookupserver("wins", addrs, nelem(addrs), t);
addrsopt(rp, OBnetbiosns, addrs, j);
break;
case OBnetbiostype:
/* p-node: peer to peer WINS queries */
byteopt(rp, OBnetbiostype, 0x2);
break;
case OBsmtpserver:
j = lookupserver("smtp", addrs, nelem(addrs), t);
addrsopt(rp, OBsmtpserver, addrs, j);
break;
case OBpop3server:
j = lookupserver("pop3", addrs, nelem(addrs), t);
addrsopt(rp, OBpop3server, addrs, j);
break;
case OBwwwserver:
j = lookupserver("www", addrs, nelem(addrs), t);
addrsopt(rp, OBwwwserver, addrs, j);
break;
case OBrootserver:
j = lookupserver("rootserver", addrs, nelem(addrs), t);
addrsopt(rp, OBrootserver, addrs, j);
break;
case OBntpserver:
j = lookupserver("ntp", addrs, nelem(addrs), t);
addrsopt(rp, OBntpserver, addrs, j);
break;
case OBtimeserver:
j = lookupserver("time", addrs, nelem(addrs), t);
addrsopt(rp, OBtimeserver, addrs, j);
break;
case OBttl:
byteopt(rp, OBttl, 255);
break;
case ODtftpserver:
/*
* This option actually should contain a hostname, BUT:
* It appears that Rpi4 PXE firmware ignores the siaddr
* and instead insists on this (DHCP option 66) to contain
* the IP address string of the TFTP server.
*/
snprint(ip4str, sizeof(ip4str), "%V", rp->bp->siaddr);
stringopt(rp, ODtftpserver, ip4str);
break;
case ODbootfile:
if(*rp->bp->file)
stringopt(rp, ODbootfile, rp->bp->file);
break;
}
if (*rp->vendorclass != '\0') {
/* point to temporary area */
op = rp->p;
omax = rp->max;
/* stash encoded options in vopts */
rp->p = vopts;
rp->max = vopts + sizeof(vopts) - 1;
if (*rp->ii.vendor != '\0')
stringopt(rp, OBvendorinfo, rp->ii.vendor);
/* add plan9 specific options */
if (strncmp((char*)rp->vendorclass, "p9-", 3) == 0
|| strncmp((char*)rp->vendorclass, "plan9_", 6) == 0){
/* emit old v4 addresses first to make sure that they fit */
addrsopt(rp, OP9fsv4, addrs, lookupserver("fs", addrs, nelem(addrs), t));
addrsopt(rp, OP9authv4, addrs, lookupserver("auth", addrs, nelem(addrs), t));
p9addrsopt(rp, OP9fs, addrs, lookupserver("fs", addrs, nelem(addrs), t));
p9addrsopt(rp, OP9auth, addrs, lookupserver("auth", addrs, nelem(addrs), t));
p9addrsopt(rp, OP9ipaddr, addrs, lookupserver("ip", addrs, nelem(addrs), t));
p9addrsopt(rp, OP9ipmask, addrs, lookupserver("ipmask", addrs, nelem(addrs), t));
p9addrsopt(rp, OP9ipgw, addrs, lookupserver("ipgw", addrs, nelem(addrs), t));
}
/* point back to packet, encapsulate vopts into packet */
j = rp->p - vopts;
rp->p = op;
rp->max = omax;
vectoropt(rp, OBvendorinfo, vopts, j);
}
ndbfree(t);
}
int
openlisten(char *net)
{
int fd, cfd;
char data[128], devdir[40];
sprint(data, "%s/udp!*!bootp", net);
cfd = announce(data, devdir);
if(cfd < 0)
fatal("can't announce: %r");
if(fprint(cfd, "headers") < 0)
fatal("can't set header mode: %r");
fprint(cfd, "ignoreadvice");
sprint(data, "%s/data", devdir);
fd = open(data, ORDWR);
if(fd < 0)
fatal("open udp data: %r");
return fd;
}
void
fatal(char *fmt, ...)
{
char buf[Maxloglen];
va_list arg;
va_start(arg, fmt);
vseprint(buf, buf+sizeof(buf), fmt, arg);
va_end(arg);
syslog(1, blog, "%s", buf);
exits(buf);
}
void
warning(char *fmt, ...)
{
char buf[Maxloglen];
va_list arg;
va_start(arg, fmt);
vseprint(buf, buf+sizeof(buf), fmt, arg);
va_end(arg);
syslog(0, blog, "%s", buf);
if(debug)
fprint(2, "%s\n", buf);
}
char*
readsysname(void)
{
static char name[128];
char *p;
int n, fd;
fd = open("/dev/sysname", OREAD);
if(fd >= 0){
n = read(fd, name, sizeof(name)-1);
close(fd);
if(n > 0){
name[n] = 0;
return name;
}
}
p = getenv("sysname");
if(p == nil || *p == 0)
return "unknown";
return p;
}
extern int
validip(uchar *ip)
{
if(ipcmp(ip, IPnoaddr) == 0)
return 0;
if(ipcmp(ip, v4prefix) == 0)
return 0;
return 1;
}
void
longopt(Req *rp, int t, long v)
{
if(rp->p + 6 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = 4;
hnputl(rp->p, v);
rp->p += 4;
op = seprint(op, oe, "%s(%ld)", optname[t], v);
}
void
addropt(Req *rp, int t, uchar *ip)
{
if(rp->p + 6 > rp->max)
return;
if (!isv4(ip)) {
if (debug)
warning("not a v4 %s server: %I", optname[t], ip);
return;
}
*rp->p++ = t;
*rp->p++ = 4;
memmove(rp->p, ip+IPv4off, 4);
rp->p += 4;
op = seprint(op, oe, "%s(%I)", optname[t], ip);
}
void
maskopt(Req *rp, int t, uchar *ip)
{
if(rp->p + 6 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = 4;
memmove(rp->p, ip+IPv4off, 4);
rp->p += 4;
op = seprint(op, oe, "%s(%M)", optname[t], ip);
}
void
addrsopt(Req *rp, int t, uchar **ip, int i)
{
int v4s, n;
if(i <= 0)
return;
if(rp->p + 2 + 4*i > rp->max)
return;
v4s = 0;
for(n = i; n-- > 0; )
if (isv4(ip[n]))
v4s++;
if (v4s <= 0) {
if (debug)
warning("no v4 %s servers", optname[t]);
return;
}
*rp->p++ = t;
*rp->p++ = 4*v4s;
op = seprint(op, oe, " %s(", optname[t]);
while(i-- > 0){
if (!isv4(*ip)) {
op = seprint(op, oe, " skipping %I ", *ip);
ip++;
continue;
}
v6tov4(rp->p, *ip);
rp->p += 4;
op = seprint(op, oe, "%I", *ip);
ip++;
if(i > 0)
op = seprint(op, oe, " ");
}
op = seprint(op, oe, ")");
}
void
p9addrsopt(Req *rp, int t, uchar **ip, int i)
{
char *pkt, *payload;
if(i <= 0 || !v6opts)
return;
pkt = (char *)rp->p;
*pkt++ = t; /* option */
pkt++; /* fill in payload length below */
payload = pkt;
*pkt++ = i; /* plan 9 address count */
op = seprint(op, oe, " %s(", optname[t]);
while(i-- > 0){
pkt = seprint(pkt, (char *)rp->max, "%I", *ip);
if ((uchar *)pkt+1 >= rp->max) {
op = seprint(op, oe, "<out of mem1>)");
return;
}
pkt++; /* leave NUL as terminator */
op = seprint(op, oe, "%I", *ip);
ip++;
if(i > 0)
op = seprint(op, oe, " ");
}
if ((uchar *)pkt - rp->p > 0377) {
op = seprint(op, oe, "<out of mem2>)");
return;
}
op = seprint(op, oe, ")");
rp->p[1] = pkt - payload; /* payload length */
rp->p = (uchar *)pkt;
}
void
byteopt(Req *rp, int t, uchar v)
{
if(rp->p + 3 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = 1;
*rp->p++ = v;
op = seprint(op, oe, "%s(%d)", optname[t], v);
}
void
termopt(Req *rp)
{
if(rp->p + 1 > rp->max)
return;
*rp->p++ = OBend;
}
void
stringopt(Req *rp, int t, char *str)
{
int n;
n = strlen(str);
if(n > 255)
n = 255;
if(rp->p+n+2 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = n;
memmove(rp->p, str, n);
rp->p += n;
op = seprint(op, oe, "%s(%s)", optname[t], str);
}
void
vectoropt(Req *rp, int t, uchar *v, int n)
{
int i;
if(n > 255) {
n = 255;
op = seprint(op, oe, "vectoropt len %d > 255 ", n);
}
if(rp->p+n+2 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = n;
memmove(rp->p, v, n);
rp->p += n;
op = seprint(op, oe, "%s(", optname[t]);
if(n > 0)
op = seprint(op, oe, "%ud", v[0]);
for(i = 1; i < n; i++)
op = seprint(op, oe, " %ud", v[i]);
op = seprint(op, oe, ")");
}
int
fromhex(int x)
{
if(x >= '0' && x <= '9')
return x - '0';
return x - 'a';
}
void
hexopt(Req *rp, int t, char *str)
{
int n;
n = strlen(str);
n /= 2;
if(n > 255)
n = 255;
if(rp->p+n+2 > rp->max)
return;
*rp->p++ = t;
*rp->p++ = n;
while(n-- > 0){
*rp->p++ = (fromhex(str[0])<<4)|fromhex(str[1]);
str += 2;
}
op = seprint(op, oe, "%s(%s)", optname[t], str);
}
void
dnsnamesopt(Req *rp, int t, char *attr, Ndbtuple *nt)
{
char val[Maxstr], *s;
uchar *d;
int n, l;
for(; nt != nil; nt = nt->entry){
if(strcmp(nt->attr, attr) != 0)
continue;
if(utf2idn(nt->val, val, sizeof(val)) <= 0)
continue;
d = &rp->p[2];
for(s = val; *s != 0; s++){
for(l = 0; *s != 0 && *s != '.'; l++)
s++;
if(l > 077)
goto Skip;
d += l+1;
if(d >= rp->max)
return;
d[-l-1] = l;
memmove(d-l, s-l, l);
if(*s != '.')
break;
}
*d++ = 0;
n = d - &rp->p[2];
if(n > 255)
continue;
rp->p[0] = t;
rp->p[1] = n;
rp->p = d;
op = seprint(op, oe, "%s(%s)", optname[t], val);
Skip:;
}
}
void
arpenter(uchar *ip, uchar *mac, uchar *src)
{
char buf[256];
int fd, n;
snprint(buf, sizeof buf, "%s/arp", net);
if((fd = open(buf, OWRITE)) < 0){
warning("couldn't open %s: %r", buf);
return;
}
n = snprint(buf, sizeof buf, "add ether %I %E %I\n", ip, mac, src);
if(write(fd, buf, n) != n)
warning("arpenter: %s: %r", buf);
close(fd);
}
char *dhcpmsgname[] =
{
[Discover] "Discover",
[Offer] "Offer",
[Request] "Request",
[Decline] "Decline",
[Ack] "Ack",
[Nak] "Nak",
[Release] "Release",
[Inform] "Inform",
};
void
logdhcp(Req *rp)
{
char buf[4096];
char *p, *e;
int i;
if(!debug)
return;
p = buf;
e = buf + sizeof(buf);
if(rp->dhcptype > 0 && rp->dhcptype <= Inform)
p = seprint(p, e, "%s(", dhcpmsgname[rp->dhcptype]);
else
p = seprint(p, e, "%d(", rp->dhcptype);
p = seprint(p, e, "%I->%I) xid(%ux)flag(%ux)", rp->up->raddr, rp->up->laddr,
nhgetl(rp->bp->xid), nhgets(rp->bp->flags));
if(rp->bp->htype == 1)
p = seprint(p, e, "ea(%E)", rp->bp->chaddr);
if(validip(rp->ciaddr))
p = seprint(p, e, "ci(%I)", rp->ciaddr);
if(validip(rp->giaddr))
p = seprint(p, e, "gi(%I)", rp->giaddr);
if(validip(rp->ip))
p = seprint(p, e, "ip(%I)", rp->ip);
if(rp->id != nil)
p = seprint(p, e, "id(%s)", rp->id);
if(rp->leasetime)
p = seprint(p, e, "leas(%d)", rp->leasetime);
if(validip(rp->server))
p = seprint(p, e, "sid(%I)", rp->server);
p = seprint(p, e, "need(");
for(i = 0; i < sizeof(rp->requested); i++)
if(rp->requested[i] != 0)
p = seprint(p, e, "%s ", optname[rp->requested[i]]);
p = seprint(p, e, ")");
USED(p);
fprint(2, "%s\n", buf);
}
void
logdhcpout(Req *rp, char *type)
{
if(!debug)
return;
fprint(2, "%s(%I->%I)id(%s)ci(%V)gi(%V)yi(%V)si(%V) %s\n",
type, rp->up->laddr, rp->up->raddr, rp->id,
rp->bp->ciaddr, rp->bp->giaddr, rp->bp->yiaddr, rp->bp->siaddr, optbuf);
}
/*
* if we get behind, it's useless to try answering since the sender
* will probably have retransmitted with a differnt sequence number.
* So dump all but the last message in the queue.
*/
void
ding(void*, char *msg)
{
if(strstr(msg, "alarm"))
noted(NCONT);
else
noted(NDFLT);
}
int
readlast(int fd, uchar *buf, int len)
{
int lastn, n;
notify(ding);
lastn = 0;
for(;;){
alarm(20);
n = read(fd, buf, len);
alarm(0);
if(n < 0){
if(lastn > 0)
return lastn;
break;
}
lastn = n;
}
return read(fd, buf, len);
}