ref: 7a29422cfefaf76315eafa82ca606f9ded9517b3
dir: /appl/cmd/ndb/cs.b/
implement Cs;
#
# Connection server translates net!machine!service into
# /net/tcp/clone 135.104.9.53!564
#
include "sys.m";
sys: Sys;
include "draw.m";
include "srv.m";
srv: Srv;
include "bufio.m";
include "attrdb.m";
attrdb: Attrdb;
Attr, Db, Dbentry, Tuples: import attrdb;
include "ip.m";
ip: IP;
include "ipattr.m";
ipattr: IPattr;
include "arg.m";
Cs: module
{
init: fn(nil: ref Draw->Context, nil: list of string);
};
# signature of dial-on-demand module
CSdial: module
{
init: fn(nil: ref Draw->Context): string;
connect: fn(): string;
};
Reply: adt
{
fid: int;
pid: int;
addrs: list of string;
err: string;
};
Cached: adt
{
expire: int;
query: string;
addrs: list of string;
};
Ncache: con 16;
cache:= array[Ncache] of ref Cached;
nextcache := 0;
rlist: list of ref Reply;
ndbfile := "/lib/ndb/local";
ndb: ref Db;
mntpt := "/net";
myname: string;
stderr: ref Sys->FD;
verbose := 0;
dialmod: CSdial;
init(ctxt: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
stderr = sys->fildes(2);
attrdb = load Attrdb Attrdb->PATH;
if(attrdb == nil)
cantload(Attrdb->PATH);
attrdb->init();
ip = load IP IP->PATH;
if(ip == nil)
cantload(IP->PATH);
ip->init();
ipattr = load IPattr IPattr->PATH;
if(ipattr == nil)
cantload(IPattr->PATH);
ipattr->init(attrdb, ip);
svcname := "#scs";
arg := load Arg Arg->PATH;
if (arg == nil)
cantload(Arg->PATH);
arg->init(args);
arg->setusage("cs [-v] [-x mntpt] [-f database] [-d dialmod]");
while((c := arg->opt()) != 0)
case c {
'v' or 'D' =>
verbose++;
'd' => # undocumented hack to replace svc/cs/cs
f := arg->arg();
if(f != nil){
dialmod = load CSdial f;
if(dialmod == nil)
cantload(f);
}
'f' =>
ndbfile = arg->earg();
'x' =>
mntpt = arg->earg();
svcname = "#scs"+svcpt(mntpt);
* =>
arg->usage();
}
if(arg->argv() != nil)
arg->usage();
arg = nil;
srv = load Srv Srv->PATH; # hosted Inferno only
if(srv != nil)
srv->init();
sys->remove(svcname+"/cs");
sys->unmount(svcname, mntpt);
publish(svcname);
if(sys->bind(svcname, mntpt, Sys->MBEFORE) < 0)
error(sys->sprint("can't bind #s on %s: %r", mntpt));
file := sys->file2chan(mntpt, "cs");
if(file == nil)
error(sys->sprint("can't make %s/cs: %r", mntpt));
sys->pctl(Sys->FORKFD|Sys->NEWPGRP, nil);
refresh();
if(dialmod != nil){
e := dialmod->init(ctxt);
if(e != nil)
error(sys->sprint("can't initialise dial-on-demand: %s", e));
}
spawn cs(file);
}
svcpt(s: string): string
{
for(i:=0; i<len s; i++)
if(s[i] == '/')
s[i] = '_';
return s;
}
publish(dir: string)
{
d := Sys->nulldir;
d.mode = 8r777;
if(sys->wstat(dir, d) < 0)
sys->fprint(sys->fildes(2), "cs: can't publish %s: %r\n", dir);
}
cantload(m: string)
{
error(sys->sprint("cannot load %s: %r", m));
}
error(s: string)
{
sys->fprint(sys->fildes(2), "cs: %s\n", s);
raise "fail:error";
}
refresh()
{
myname = sysname();
if(ndb == nil){
ndb2 := Db.open(ndbfile);
if(ndb2 == nil){
err := sys->sprint("%r");
ndb2 = Db.open("/lib/ndb/inferno"); # try to get service map at least
if(ndb2 == nil)
sys->fprint(sys->fildes(2), "cs: warning: can't open %s: %s\n", ndbfile, err); # continue without it
}
ndb = Db.open(mntpt+"/ndb");
if(ndb != nil)
ndb = ndb.append(ndb2);
else
ndb = ndb2;
}else
ndb.reopen();
}
sysname(): string
{
t := rf("/dev/sysname");
if(t != nil)
return t;
t = rf("#e/sysname");
if(t == nil){
s := rf(mntpt+"/ndb");
if(s != nil){
db := Db.sopen(s);
if(db != nil){
(e, nil) := db.find(nil, "sys");
if(e != nil)
t = e.findfirst("sys");
}
}
}
if(t != nil){
fd := sys->open("/dev/sysname", Sys->OWRITE);
if(fd != nil)
sys->fprint(fd, "%s", t);
}
return t;
}
rf(name: string): string
{
fd := sys->open(name, Sys->OREAD);
buf := array[512] of byte;
n := sys->read(fd, buf, len buf);
if(n <= 0)
return nil;
return string buf[0:n];
}
cs(file: ref Sys->FileIO)
{
pidc := chan of int;
donec := chan of ref Reply;
for (;;) {
alt {
(nil, buf, fid, wc) := <-file.write =>
cleanfid(fid); # each write cancels previous requests
if(dialmod != nil){
e := dialmod->connect();
if(e != nil){
if(len e > 5 && e[0:5]=="fail:")
e = e[5:];
if(e == "")
e = "unknown error";
wc <-= (0, "cs: dial on demand: "+e);
break;
}
}
if(wc != nil){
nbytes := len buf;
query := string buf;
if(query == "refresh"){
refresh();
wc <-= (nbytes, nil);
break;
}
now := time();
r := ref Reply;
r.fid = fid;
spawn request(r, query, nbytes, now, wc, pidc, donec);
r.pid = <-pidc;
rlist = r :: rlist;
}
(off, nbytes, fid, rc) := <-file.read =>
if(rc != nil){
r := findfid(fid);
if(r != nil)
reply(r, off, nbytes, rc);
else
rc <-= (nil, "unknown request");
} else
; # cleanfid(fid); # compensate for csendq in file2chan
r := <-donec =>
r.pid = 0;
}
}
}
findfid(fid: int): ref Reply
{
for(rl := rlist; rl != nil; rl = tl rl){
r := hd rl;
if(r.fid == fid)
return r;
}
return nil;
}
cleanfid(fid: int)
{
rl := rlist;
rlist = nil;
for(; rl != nil; rl = tl rl){
r := hd rl;
if(r.fid != fid)
rlist = r :: rlist;
else
killgrp(r.pid);
}
}
killgrp(pid: int)
{
if(pid != 0){
fd := sys->open("#p/"+string pid+"/ctl", Sys->OWRITE);
if(fd == nil || sys->fprint(fd, "killgrp") < 0)
sys->fprint(stderr, "cs: can't killgrp %d: %r\n", pid);
}
}
request(r: ref Reply, query: string, nbytes: int, now: int, wc: chan of (int, string), pidc: chan of int, donec: chan of ref Reply)
{
pidc <-= sys->pctl(Sys->NEWPGRP, nil);
if(query != nil && query[0] == '!'){
# general query
(r.addrs, r.err) = genquery(query[1:]);
}else{
(r.addrs, r.err) = xlate(query, now);
if(r.addrs == nil && r.err == nil)
r.err = "cs: can't translate address";
}
if(r.err != nil){
if(verbose)
sys->fprint(stderr, "cs: %s: %s\n", query, r.err);
wc <-= (0, r.err);
} else
wc <-= (nbytes, nil);
donec <-= r;
}
reply(r: ref Reply, off: int, nbytes: int, rc: chan of (array of byte, string))
{
if(r.err != nil){
rc <-= (nil, r.err);
return;
}
addr: string = nil;
if(r.addrs != nil){
addr = hd r.addrs;
r.addrs = tl r.addrs;
}
off = 0; # this version ignores offset
rc <-= reads(addr, off, nbytes);
}
#
# return the file2chan reply for a read of the given string
#
reads(str: string, off, nbytes: int): (array of byte, string)
{
bstr := array of byte str;
slen := len bstr;
if(off < 0 || off >= slen)
return (nil, nil);
if(off + nbytes > slen)
nbytes = slen - off;
if(nbytes <= 0)
return (nil, nil);
return (bstr[off:off+nbytes], nil);
}
lookcache(query: string, now: int): ref Cached
{
for(i:=0; i<len cache; i++){
c := cache[i];
if(c != nil && c.query == query && now < c.expire){
if(verbose)
sys->print("cache: %s -> %s\n", query, hd c.addrs);
return c;
}
}
return nil;
}
putcache(query: string, addrs: list of string, now: int)
{
ce := ref Cached;
ce.expire = now+120;
ce.query = query;
ce.addrs = addrs;
cache[nextcache] = ce;
nextcache = (nextcache+1)%Ncache;
}
xlate(address: string, now: int): (list of string, string)
{
n: int;
l, rl, results: list of string;
repl, netw, mach, service: string;
ce := lookcache(address, now);
if(ce != nil && ce.addrs != nil)
return (ce.addrs, nil);
(n, l) = sys->tokenize(address, "!\n");
if(n < 2)
return (nil, "bad format request");
netw = hd l;
if(netw == "net")
netw = "tcp"; # TO DO: better (needs lib/ndb)
if(!isnetwork(netw))
return (nil, "network unavailable "+netw);
l = tl l;
if(!isipnet(netw)) {
repl = mntpt + "/" + netw + "/clone ";
for(;;){
repl += hd l;
if((l = tl l) == nil)
break;
repl += "!";
}
return (repl :: nil, nil); # no need to cache
}
if(n != 3)
return (nil, "bad format request");
mach = hd l;
service = hd tl l;
if(!isnumeric(service)) {
s := xlatesvc(netw, service);
if(s == nil){
if(srv != nil)
s = srv->ipn2p(netw, service);
if(s == nil)
return (nil, "cs: can't translate service");
}
service = s;
}
attr := ipattr->dbattr(mach);
if(mach == "*")
l = "" :: nil;
else if(attr != "ip") {
# Symbolic server == "$SVC"
if(mach[0] == '$' && len mach > 1 && ndb != nil){
(s, nil) := ipattr->findnetattr(ndb, "sys", myname, mach[1:]);
if(s == nil){
names := dblook("infernosite", "", mach[1:]);
if(names == nil)
return (nil, "cs: can't translate "+mach);
s = hd names;
}
mach = s;
attr = ipattr->dbattr(mach);
}
if(attr == "sys"){
results = dblook("sys", mach, "ip");
if(results != nil)
attr = "ip";
}
if(attr != "ip"){
err: string;
(results, err) = querydns(mach, "ip");
if(err != nil)
return (nil, err);
}else if(results == nil)
results = mach :: nil;
l = results;
if(l == nil){
if(srv != nil)
l = srv->iph2a(mach);
if(l == nil)
return (nil, "cs: unknown host");
}
} else
l = mach :: nil;
while(l != nil) {
s := hd l;
l = tl l;
dnetw := netw;
if(s != nil){
(divert, err) := ipattr->findnetattr(ndb, "ip", s, "divert-"+netw);
if(err == nil && divert != nil){
dnetw = divert;
if(!isnetwork(dnetw))
return (nil, "network unavailable "+dnetw); # XXX should only give up if all addresses fail?
}
}
if(s != "")
s[len s] = '!';
s += service;
repl = mntpt+"/"+dnetw+"/clone "+s;
if(verbose)
sys->fprint(stderr, "cs: %s!%s!%s -> %s\n", netw, mach, service, repl);
rl = repl :: rl;
}
rl = reverse(rl);
putcache(address, rl, now);
return (rl, nil);
}
querydns(name: string, rtype: string): (list of string, string)
{
fd := sys->open(mntpt+"/dns", Sys->ORDWR);
if(fd == nil)
return (nil, nil);
if(sys->fprint(fd, "%s %s", name, rtype) < 0)
return (nil, sys->sprint("%r"));
rl: list of string;
buf := array[256] of byte;
sys->seek(fd, big 0, 0);
while((n := sys->read(fd, buf, len buf)) > 0){
# name rtype value
(nf, fld) := sys->tokenize(string buf[0:n], " \t");
if(nf != 3){
sys->fprint(stderr, "cs: odd result from dns: %s\n", string buf[0:n]);
continue;
}
rl = hd tl tl fld :: rl;
}
return (reverse(rl), nil);
}
dblook(attr: string, val: string, rattr: string): list of string
{
rl: list of string;
ptr: ref Attrdb->Dbptr;
for(;;){
e: ref Dbentry;
(e, ptr) = ndb.findbyattr(ptr, attr, val, rattr);
if(e == nil)
break;
for(l := e.findbyattr(attr, val, rattr); l != nil; l = tl l){
(nil, al) := hd l;
for(; al != nil; al = tl al)
if(!inlist((hd al).val, rl))
rl = (hd al).val :: rl;
}
}
return reverse(rl);
}
inlist(s: string, l: list of string): int
{
for(; l != nil; l = tl l)
if(hd l == s)
return 1;
return 0;
}
reverse(l: list of string): list of string
{
t: list of string;
for(; l != nil; l = tl l)
t = hd l :: t;
return t;
}
isnumeric(a: string): int
{
i, c: int;
for(i = 0; i < len a; i++) {
c = a[i];
if(c < '0' || c > '9')
return 0;
}
return 1;
}
nets: list of string;
isnetwork(s: string) : int
{
if(find(s, nets))
return 1;
(ok, nil) := sys->stat(mntpt+"/"+s+"/clone");
if(ok >= 0) {
nets = s :: nets;
return 1;
}
return 0;
}
find(e: string, l: list of string) : int
{
for(; l != nil; l = tl l)
if (e == hd l)
return 1;
return 0;
}
isipnet(s: string) : int
{
return s == "net" || s == "tcp" || s == "udp" || s == "il";
}
xlatesvc(proto: string, s: string): string
{
if(ndb == nil || s == nil || isnumeric(s))
return s;
(e, nil) := ndb.findbyattr(nil, proto, s, "port");
if(e == nil)
return nil;
matches := e.findbyattr(proto, s, "port");
if(matches == nil)
return nil;
(ts, al) := hd matches;
restricted := "";
if(ts.hasattr("restricted"))
restricted = "!r";
if(verbose > 1)
sys->print("%s=%q port=%s%s\n", proto, s, (hd al).val, restricted);
return (hd al).val+restricted;
}
time(): int
{
timefd := sys->open("/dev/time", Sys->OREAD);
if(timefd == nil)
return 0;
buf := array[128] of byte;
sys->seek(timefd, big 0, 0);
n := sys->read(timefd, buf, len buf);
if(n < 0)
return 0;
return int ((big string buf[0:n]) / big 1000000);
}
#
# general query: attr1=val1 attr2=val2 ... finds matching tuple(s)
# where attr1 is the key and val1 can't be *
#
genquery(query: string): (list of string, string)
{
(tups, err) := attrdb->parseline(query, 0);
if(err != nil)
return (nil, "bad query: "+err);
if(tups == nil)
return (nil, "bad query");
pairs := tups.pairs;
a0 := (hd pairs).attr;
if(a0 == "ipinfo")
return (nil, "ipinfo not yet supported");
v0 := (hd pairs).val;
# if((a0 == "dom" || a0 == "ip") && v0 != nil){
# query dns ...
# }
ptr: ref Attrdb->Dbptr;
e: ref Dbentry;
for(;;){
(e, ptr) = ndb.findpair(ptr, a0, v0);
if(e == nil)
break;
for(l := e.lines; l != nil; l = tl l)
if(qmatch(hd l, tl pairs)){
ls: list of string;
for(l = e.lines; l != nil; l = tl l)
ls = tuptext(hd l) :: ls;
return (reverse(ls), nil);
}
}
return (nil, "no match");
}
#
# see if set of tuples t contains every non-* attr/val pair
#
qmatch(t: ref Tuples, av: list of ref Attr): int
{
Match:
for(; av != nil; av = tl av){
a := hd av;
for(pl := t.pairs; pl != nil; pl = tl pl)
if((hd pl).attr == a.attr &&
(a.val == "*" || a.val == (hd pl).val))
continue Match;
return 0;
}
return 1;
}
tuptext(t: ref Tuples): string
{
s: string;
for(pl := t.pairs; pl != nil; pl = tl pl){
p := hd pl;
if(s != nil)
s[len s] = ' ';
s += sys->sprint("%s=%q", p.attr, p.val);
}
return s;
}