ref: 44ce0097b612a1fefd754065bdf8d9d2e5ef60c8
dir: /appl/lib/dhcpserver.b/
implement Dhcpserver;
include "sys.m";
sys: Sys;
sprint: import sys;
include "ip.m";
ip: IP;
IPaddr: import ip;
include "encoding.m";
base16: Encoding;
include "lists.m";
lists: Lists;
include "ether.m";
ether: Ether;
include "dhcpserver.m";
debug: con 0;
tdnames := array[] of {
nil, "discover", "offer", "request", "decline", "ack", "nak", "release", "inform",
};
# option value types, for converting to text
OTstr, OTips, OTint16, OTint32, OTother: con iota;
optstring := array[] of {
Ohostname, Odomainname, Orootpath, Omessage, Otftpservername, Obootfile,
};
optips := array[] of {
Osubnetmask, Orouters, Odns, Obroadcast, Oreqipaddr, Oserverid,
};
optint16 := array[] of {
Omaxmsgsize,
};
optint32 := array[] of {
Oleasetime, Orenewaltime, Orebindingtime,
};
optnames := array[] of {
Opad => "pad",
Oend => "end",
Osubnetmask => "ipmask",
Orouters => "ipgw",
Odns => "dns",
Ohostname => "sys",
Odomainname => "dnsdomain",
Orootpath => "rootpath",
Obroadcast => "ipbroadcast",
Oreqipaddr => "reqipaddr",
Oleasetime => "leasetime",
Ooptionoverload => "optionoverload",
Odhcpmsgtype => "dhcpmsgtype",
Oserverid => "serverid",
Oparamreq => "paramreq",
Omessage => "message",
Omaxmsgsize => "maxmsgsize",
Orenewaltime => "renewaltime",
Orebindingtime => "rebindingtime",
Ovendorclass => "vendorclass",
Oclientid => "clientid",
Otftpservername => "tftp",
Obootfile => "bootf",
};
init()
{
sys = load Sys Sys->PATH;
ip = load IP IP->PATH;
ip->init();
base16 = load Encoding Encoding->BASE16PATH;
lists = load Lists Lists->PATH;
ether = load Ether Ether->PATH;
ether->init();
}
optsparse(d: array of byte): list of ref Opt
{
if(g32(d, 0).t0 != Moptions)
return nil;
l: list of ref Opt;
o := 4;
while(o < len d) {
code := int d[o++];
if(code == Oend)
break;
if(code == Opad)
continue;
if(o >= len d) {
say("bad options, length outside packet");
return nil;
}
n := int d[o++];
if(o+n > len d) {
say("bad options, value outside packet");
return nil;
}
l = ref Opt(code, d[o:o+n])::l;
o += n;
}
return lists->reverse(l);
}
optssize(l: list of ref Opt): int
{
o := 4;
for(; l != nil; l = tl l)
case (hd l).code {
Opad or
Oend =>
o += 1;
* =>
o += 1+1+len (hd l).v;
}
return o;
}
optspack(l: list of ref Opt, buf: array of byte)
{
if(l == nil)
return;
o := 0;
o = p32(buf, o, Moptions);
for(; l != nil; l = tl l) {
opt := hd l;
if(o >= len buf)
return warn("response options too long (code)");
buf[o++] = byte opt.code;
if(opt.code == Opad)
continue;
if(opt.code == Oend) {
if(len l != 1)
raise "option 'end' not last";
break;
}
if(o+1+len opt.v > len buf)
return warn("response options too long (len/value)");
buf[o++] = byte len opt.v;
buf[o:] = opt.v;
o += len opt.v;
}
}
optname(code: int): string
{
if(code >= 0 && code < len optnames)
s := optnames[code];
if(s == nil)
s = string code;
return s;
}
has(a: array of int, v: int): int
{
for(i := 0; i < len a; i++)
if(a[i] == v)
return 1;
return 0;
}
opttype(code: int): int
{
if(has(optstring, code))
return OTstr;
if(has(optips, code))
return OTips;
if(has(optint16, code))
return OTint16;
if(has(optint32, code))
return OTint32;
return OTother;
}
optstext(l: list of ref Opt): string
{
s := "";
for(; l != nil; l = tl l) {
o := hd l;
s += "\t\t"+optname(o.code);
if(o.v == nil) {
s += "\n";
continue;
}
s += "=";
ot := opttype(o.code);
if(o.code == Odhcpmsgtype && len o.v == 1 && (t := int o.v[0]) >= 0 && t < len tdnames && tdnames[t] != nil) {
s += sprint("%s", tdnames[t]);
} else if(ot == OTstr) {
s += sprint("\"%s\"", string o.v);
} else if(ot == OTips && len o.v % 4 == 0) {
v := o.v;
ips := "";
while(len v >= 4) {
ips += ","+IPaddr.newv4(v[:4]).text();
v = v[4:];
}
if(ips != nil)
ips = ips[1:];
s += sprint("%s", ips);
} else if(ot == OTint16 && len o.v == 2) {
s += sprint("%d", g16(o.v, 0).t0);
} else if(ot == OTint32 && len o.v == 4) {
s += sprint("%d", g32(o.v, 0).t0);
} else {
s += sprint("'%s'", base16->enc(o.v));
}
s += "\n";
}
return s;
}
Dhcpmsg.unpack(buf: array of byte): (ref Dhcpmsg, string)
{
if(len buf < Minmsglen)
return (nil, sprint("too short, %d < minimum %d", len buf, Minmsglen));
m := ref Dhcpmsg;
o := 0;
m.op = int buf[o++];
m.htype = int buf[o++];
m.hlen = int buf[o++];
if(m.hlen > 16)
return (nil, sprint("bad hlen %d", m.hlen));
m.hops = int buf[o++];
(m.xid, o) = g32(buf, o);
(m.secs, o) = g16(buf, o);
(m.flags, o) = g16(buf, o);
m.ciaddr = IPaddr.newv4(buf[o:o+4]);
o += 4;
m.yiaddr = IPaddr.newv4(buf[o:o+4]);
o += 4;
m.siaddr = IPaddr.newv4(buf[o:o+4]);
o += 4;
m.giaddr = IPaddr.newv4(buf[o:o+4]);
o += 4;
m.chaddr = buf[o:o+m.hlen];
o += 16;
m.sname = cstr(buf[o:o+64]);
o += 64;
m.file = cstr(buf[o:o+128]);
o += 128;
m.options = buf[o:];
m.opts = optsparse(m.options);
return (m, nil);
}
Dhcpmsg.pack(m: self ref Dhcpmsg): array of byte
{
size := 7*4+16+64+128;
# for dhcp, no minimum length. bootp needs 64 bytes options.
optsize := len m.options;
if(len m.options >= 4 && g32(m.options, 0).t0 == Moptions)
optsize = optssize(m.opts);
if(0 && optsize < 64)
optsize = 64;
size += optsize;
buf := array[size] of {* => byte 0};
o := 0;
buf[o++] = byte m.op;
buf[o++] = byte m.htype;
buf[o++] = byte m.hlen;
buf[o++] = byte m.hops;
o = p32(buf, o, m.xid);
o = p16(buf, o, m.secs);
o = p16(buf, o, m.flags);
o = pbuf(buf, o, m.ciaddr.v4());
o = pbuf(buf, o, m.yiaddr.v4());
o = pbuf(buf, o, m.siaddr.v4());
o = pbuf(buf, o, m.giaddr.v4());
buf[o:] = m.chaddr;
o += 16;
buf[o:] = array of byte m.sname;
o += 64;
buf[o:] = array of byte m.file;
o += 128;
if(len m.options >= 4 && g32(m.options, 0).t0 == Moptions)
optspack(m.opts, buf[o:]);
else if(m.options != nil)
buf[o:] = m.options;
return buf;
}
Dhcpmsg.text(m: self ref Dhcpmsg): string
{
s := "Dhcpmsg(\n";
s += sprint(" op=%d\n", int m.op);
s += sprint(" htype=%d\n", m.htype);
s += sprint(" hlen=%d\n", m.hlen);
s += sprint(" hops=%d\n", m.hops);
s += sprint(" xid=%ud\n", m.xid);
s += sprint(" secs=%ud\n", m.secs);
s += sprint(" ciaddr=%s\n", m.ciaddr.text());
s += sprint(" yiaddr=%s\n", m.yiaddr.text());
s += sprint(" siaddr=%s\n", m.siaddr.text());
s += sprint(" giaddr=%s\n", m.giaddr.text());
s += sprint(" hwaddr=%q\n", ether->text(m.chaddr));
s += sprint(" sname=%q\n", m.sname);
s += sprint(" file=%q\n", m.file);
if(len m.options >= 4) {
magic := g32(m.options, 0).t0;
s += sprint(" magic=%#ux\n", magic);
if(magic == Moptions) {
s += "\toptions=(\n";
s += optstext(m.opts);
s += "\t)\n";
} else if (magic == Mp9)
s += sprint("\toptions=%q\n", cstr(m.options[4:]));
}
s += ")";
return s;
}
cstr(buf: array of byte): string
{
for(i := 0; i < len buf; i++)
if(buf[i] == byte 0)
break;
return string buf[:i];
}
g32(d: array of byte, o: int): (int, int)
{
v := 0;
v |= int d[o++]<<24;
v |= int d[o++]<<16;
v |= int d[o++]<<8;
v |= int d[o++]<<0;
return (v, o);
}
g16(d: array of byte, o: int): (int, int)
{
v := 0;
v |= int d[o++]<<8;
v |= int d[o++]<<0;
return (v, o);
}
p32(d: array of byte, o: int, v: int): int
{
d[o++] = byte (v>>24);
d[o++] = byte (v>>16);
d[o++] = byte (v>>8);
d[o++] = byte (v>>0);
return o;
}
p16(d: array of byte, o: int, v: int): int
{
d[o++] = byte (v>>8);
d[o++] = byte (v>>0);
return o;
}
pbuf(d: array of byte, o: int, buf: array of byte): int
{
d[o:] = buf;
return o+len buf;
}
warn(s: string)
{
say(s);
}
say(s: string)
{
if(debug)
sys->fprint(sys->fildes(2), "%s\n", s);
}