ref: 38c0cf0737de03906729054ad7b7b011dd1ca475
dir: /appl/lib/styx.b/
implement Styx;
include "sys.m";
sys: Sys;
include "styx.m";
STR: con BIT16SZ; # string length
TAG: con BIT16SZ;
FID: con BIT32SZ;
QID: con BIT8SZ+BIT32SZ+BIT64SZ;
LEN: con BIT16SZ; # stat and qid array lengths
COUNT: con BIT32SZ;
OFFSET: con BIT64SZ;
H: con BIT32SZ+BIT8SZ+BIT16SZ; # minimum header length: size[4] type tag[2]
#
# the following array could be shorter if it were indexed by (type-Tversion)
#
hdrlen := array[Tmax] of
{
Tversion => H+COUNT+STR, # size[4] Tversion tag[2] msize[4] version[s]
Rversion => H+COUNT+STR, # size[4] Rversion tag[2] msize[4] version[s]
Tauth => H+FID+STR+STR, # size[4] Tauth tag[2] afid[4] uname[s] aname[s]
Rauth => H+QID, # size[4] Rauth tag[2] aqid[13]
Rerror => H+STR, # size[4] Rerror tag[2] ename[s]
Tflush => H+TAG, # size[4] Tflush tag[2] oldtag[2]
Rflush => H, # size[4] Rflush tag[2]
Tattach => H+FID+FID+STR+STR, # size[4] Tattach tag[2] fid[4] afid[4] uname[s] aname[s]
Rattach => H+QID, # size[4] Rattach tag[2] qid[13]
Twalk => H+FID+FID+LEN, # size[4] Twalk tag[2] fid[4] newfid[4] nwname[2] nwname*(wname[s])
Rwalk => H+LEN, # size[4] Rwalk tag[2] nwqid[2] nwqid*(wqid[13])
Topen => H+FID+BIT8SZ, # size[4] Topen tag[2] fid[4] mode[1]
Ropen => H+QID+COUNT, # size[4] Ropen tag[2] qid[13] iounit[4]
Tcreate => H+FID+STR+BIT32SZ+BIT8SZ, # size[4] Tcreate tag[2] fid[4] name[s] perm[4] mode[1]
Rcreate => H+QID+COUNT, # size[4] Rcreate tag[2] qid[13] iounit[4]
Tread => H+FID+OFFSET+COUNT, # size[4] Tread tag[2] fid[4] offset[8] count[4]
Rread => H+COUNT, # size[4] Rread tag[2] count[4] data[count]
Twrite => H+FID+OFFSET+COUNT, # size[4] Twrite tag[2] fid[4] offset[8] count[4] data[count]
Rwrite => H+COUNT, # size[4] Rwrite tag[2] count[4]
Tclunk => H+FID, # size[4] Tclunk tag[2] fid[4]
Rclunk => H, # size[4] Rclunk tag[2]
Tremove => H+FID, # size[4] Tremove tag[2] fid[4]
Rremove => H, # size[4] Rremove tag[2]
Tstat => H+FID, # size[4] Tstat tag[2] fid[4]
Rstat => H+LEN, # size[4] Rstat tag[2] stat[n]
Twstat => H+FID+LEN, # size[4] Twstat tag[2] fid[4] stat[n]
Rwstat => H, # size[4] Rwstat tag[2]
};
init()
{
sys = load Sys Sys->PATH;
}
utflen(s: string): int
{
# the domain is 21-bit unicode
n := l := len s;
for(i:=0; i<l; i++)
if((c := s[i]) > 16r7F){
n++;
if(c > 16r7FF){
n++;
if(c > 16rFFFF)
n++;
}
}
return n;
}
packdirsize(d: Sys->Dir): int
{
return STATFIXLEN+utflen(d.name)+utflen(d.uid)+utflen(d.gid)+utflen(d.muid);
}
packdir(f: Sys->Dir): array of byte
{
ds := packdirsize(f);
a := array[ds] of byte;
# size[2]
a[0] = byte (ds-LEN);
a[1] = byte ((ds-LEN)>>8);
# type[2]
a[2] = byte f.dtype;
a[3] = byte (f.dtype>>8);
# dev[4]
a[4] = byte f.dev;
a[5] = byte (f.dev>>8);
a[6] = byte (f.dev>>16);
a[7] = byte (f.dev>>24);
# qid.type[1]
# qid.vers[4]
# qid.path[8]
pqid(a, 8, f.qid);
# mode[4]
a[21] = byte f.mode;
a[22] = byte (f.mode>>8);
a[23] = byte (f.mode>>16);
a[24] = byte (f.mode>>24);
# atime[4]
a[25] = byte f.atime;
a[26] = byte (f.atime>>8);
a[27] = byte (f.atime>>16);
a[28] = byte (f.atime>>24);
# mtime[4]
a[29] = byte f.mtime;
a[30] = byte (f.mtime>>8);
a[31] = byte (f.mtime>>16);
a[32] = byte (f.mtime>>24);
# length[8]
p64(a, 33, big f.length);
# name[s]
i := pstring(a, 33+BIT64SZ, f.name);
i = pstring(a, i, f.uid);
i = pstring(a, i, f.gid);
i = pstring(a, i, f.muid);
if(i != len a)
raise "assertion: Styx->packdir: bad count"; # can't happen unless packedsize is wrong
return a;
}
pqid(a: array of byte, o: int, q: Sys->Qid): int
{
a[o] = byte q.qtype;
v := q.vers;
a[o+1] = byte v;
a[o+2] = byte (v>>8);
a[o+3] = byte (v>>16);
a[o+4] = byte (v>>24);
v = int q.path;
a[o+5] = byte v;
a[o+6] = byte (v>>8);
a[o+7] = byte (v>>16);
a[o+8] = byte (v>>24);
v = int (q.path >> 32);
a[o+9] = byte v;
a[o+10] = byte (v>>8);
a[o+11] = byte (v>>16);
a[o+12] = byte (v>>24);
return o+QID;
}
pstring(a: array of byte, o: int, s: string): int
{
sa := array of byte s; # could do conversion ourselves
n := len sa;
a[o] = byte n;
a[o+1] = byte (n>>8);
a[o+2:] = sa;
return o+LEN+n;
}
p32(a: array of byte, o: int, v: int): int
{
a[o] = byte v;
a[o+1] = byte (v>>8);
a[o+2] = byte (v>>16);
a[o+3] = byte (v>>24);
return o+BIT32SZ;
}
p64(a: array of byte, o: int, b: big): int
{
i := int b;
a[o] = byte i;
a[o+1] = byte (i>>8);
a[o+2] = byte (i>>16);
a[o+3] = byte (i>>24);
i = int (b>>32);
a[o+4] = byte i;
a[o+5] = byte (i>>8);
a[o+6] = byte (i>>16);
a[o+7] = byte (i>>24);
return o+BIT64SZ;
}
unpackdir(a: array of byte): (int, Sys->Dir)
{
dir: Sys->Dir;
if(len a < STATFIXLEN)
return (0, dir);
# size[2]
sz := ((int a[1] << 8) | int a[0])+LEN; # bytes this packed dir should occupy
if(len a < sz)
return (0, dir);
# type[2]
dir.dtype = (int a[3]<<8) | int a[2];
# dev[4]
dir.dev = (((((int a[7] << 8) | int a[6]) << 8) | int a[5]) << 8) | int a[4];
# qid.type[1]
# qid.vers[4]
# qid.path[8]
dir.qid = gqid(a, 8);
# mode[4]
dir.mode = (((((int a[24] << 8) | int a[23]) << 8) | int a[22]) << 8) | int a[21];
# atime[4]
dir.atime = (((((int a[28] << 8) | int a[27]) << 8) | int a[26]) << 8) | int a[25];
# mtime[4]
dir.mtime = (((((int a[32] << 8) | int a[31]) << 8) | int a[30]) << 8) | int a[29];
# length[8]
v0 := (((((int a[36] << 8) | int a[35]) << 8) | int a[34]) << 8) | int a[33];
v1 := (((((int a[40] << 8) | int a[39]) << 8) | int a[38]) << 8) | int a[37];
dir.length = (big v1 << 32) | (big v0 & 16rFFFFFFFF);
# name[s], uid[s], gid[s], muid[s]
i: int;
(dir.name, i) = gstring(a, 41);
(dir.uid, i) = gstring(a, i);
(dir.gid, i) = gstring(a, i);
(dir.muid, i) = gstring(a, i);
if(i != sz)
return (0, dir);
return (i, dir);
}
gqid(f: array of byte, i: int): Sys->Qid
{
qtype := int f[i];
vers := (((((int f[i+4] << 8) | int f[i+3]) << 8) | int f[i+2]) << 8) | int f[i+1];
i += BIT8SZ+BIT32SZ;
path0 := (((((int f[i+3] << 8) | int f[i+2]) << 8) | int f[i+1]) << 8) | int f[i];
i += BIT32SZ;
path1 := (((((int f[i+3] << 8) | int f[i+2]) << 8) | int f[i+1]) << 8) | int f[i];
path := (big path1 << 32) | (big path0 & 16rFFFFFFFF);
return (path, vers, qtype);
}
g32(f: array of byte, i: int): int
{
return (((((int f[i+3] << 8) | int f[i+2]) << 8) | int f[i+1]) << 8) | int f[i];
}
g64(f: array of byte, i: int): big
{
b0 := (((((int f[i+3] << 8) | int f[i+2]) << 8) | int f[i+1]) << 8) | int f[i];
b1 := (((((int f[i+7] << 8) | int f[i+6]) << 8) | int f[i+5]) << 8) | int f[i+4];
return (big b1 << 32) | (big b0 & 16rFFFFFFFF);
}
gstring(a: array of byte, o: int): (string, int)
{
if(o < 0 || o+STR > len a)
return (nil, -1);
l := (int a[o+1] << 8) | int a[o];
o += STR;
e := o+l;
if(e > len a)
return (nil, -1);
return (string a[o:e], e);
}
ttag2type := array[] of {
tagof Tmsg.Readerror => 0,
tagof Tmsg.Version => Tversion,
tagof Tmsg.Auth => Tauth,
tagof Tmsg.Attach => Tattach,
tagof Tmsg.Flush => Tflush,
tagof Tmsg.Walk => Twalk,
tagof Tmsg.Open => Topen,
tagof Tmsg.Create => Tcreate,
tagof Tmsg.Read => Tread,
tagof Tmsg.Write => Twrite,
tagof Tmsg.Clunk => Tclunk,
tagof Tmsg.Stat => Tstat,
tagof Tmsg.Remove => Tremove,
tagof Tmsg.Wstat => Twstat,
};
Tmsg.mtype(t: self ref Tmsg): int
{
return ttag2type[tagof t];
}
Tmsg.packedsize(t: self ref Tmsg): int
{
mtype := ttag2type[tagof t];
if(mtype <= 0)
return 0;
ml := hdrlen[mtype];
pick m := t {
Version =>
ml += utflen(m.version);
Auth =>
ml += utflen(m.uname)+utflen(m.aname);
Attach =>
ml += utflen(m.uname)+utflen(m.aname);
Walk =>
for(i:=0; i<len m.names; i++)
ml += STR+utflen(m.names[i]);
Create =>
ml += utflen(m.name);
Write =>
ml += len m.data;
Wstat =>
ml += packdirsize(m.stat);
}
return ml;
}
Tmsg.pack(t: self ref Tmsg): array of byte
{
if(t == nil)
return nil;
ds := t.packedsize();
if(ds <= 0)
return nil;
d := array[ds] of byte;
d[0] = byte ds;
d[1] = byte (ds>>8);
d[2] = byte (ds>>16);
d[3] = byte (ds>>24);
d[4] = byte ttag2type[tagof t];
d[5] = byte t.tag;
d[6] = byte (t.tag >> 8);
pick m := t {
Version =>
p32(d, H, m.msize);
pstring(d, H+COUNT, m.version);
Auth =>
p32(d, H, m.afid);
o := pstring(d, H+FID, m.uname);
pstring(d, o, m.aname);
Flush =>
v := m.oldtag;
d[H] = byte v;
d[H+1] = byte (v>>8);
Attach =>
p32(d, H, m.fid);
p32(d, H+FID, m.afid);
o := pstring(d, H+2*FID, m.uname);
pstring(d, o, m.aname);
Walk =>
d[H] = byte m.fid;
d[H+1] = byte (m.fid>>8);
d[H+2] = byte (m.fid>>16);
d[H+3] = byte (m.fid>>24);
d[H+FID] = byte m.newfid;
d[H+FID+1] = byte (m.newfid>>8);
d[H+FID+2] = byte (m.newfid>>16);
d[H+FID+3] = byte (m.newfid>>24);
n := len m.names;
d[H+2*FID] = byte n;
d[H+2*FID+1] = byte (n>>8);
o := H+2*FID+LEN;
for(i := 0; i < n; i++)
o = pstring(d, o, m.names[i]);
Open =>
p32(d, H, m.fid);
d[H+FID] = byte m.mode;
Create =>
p32(d, H, m.fid);
o := pstring(d, H+FID, m.name);
p32(d, o, m.perm);
d[o+BIT32SZ] = byte m.mode;
Read =>
p32(d, H, m.fid);
p64(d, H+FID, m.offset);
p32(d, H+FID+OFFSET, m.count);
Write =>
p32(d, H, m.fid);
p64(d, H+FID, m.offset);
n := len m.data;
p32(d, H+FID+OFFSET, n);
d[H+FID+OFFSET+COUNT:] = m.data;
Clunk or Remove or Stat =>
p32(d, H, m.fid);
Wstat =>
p32(d, H, m.fid);
stat := packdir(m.stat);
n := len stat;
d[H+FID] = byte n;
d[H+FID+1] = byte (n>>8);
d[H+FID+LEN:] = stat;
* =>
raise sys->sprint("assertion: Styx->Tmsg.pack: bad tag: %d", tagof t);
}
return d;
}
Tmsg.unpack(f: array of byte): (int, ref Tmsg)
{
if(len f < H)
return (0, nil);
size := (int f[1] << 8) | int f[0];
size |= ((int f[3] << 8) | int f[2]) << 16;
if(len f != size){
if(len f < size)
return (0, nil); # need more data
f = f[0:size]; # trim to exact length
}
mtype := int f[4];
if(mtype >= len hdrlen || (mtype&1) != 0 || size < hdrlen[mtype])
return (-1, nil);
tag := (int f[6] << 8) | int f[5];
fid := 0;
if(hdrlen[mtype] >= H+FID)
fid = g32(f, H); # fid is always in same place: extract it once for all if there
# return out of each case body for a legal message;
# break out of the case for an illegal one
Decode:
case mtype {
* =>
sys->print("styx: Tmsg.unpack: bad type %d\n", mtype);
Tversion =>
msize := fid;
(version, o) := gstring(f, H+COUNT);
if(o <= 0)
break;
return (o, ref Tmsg.Version(tag, msize, version));
Tauth =>
(uname, o1) := gstring(f, H+FID);
(aname, o2) := gstring(f, o1);
if(o2 <= 0)
break;
return (o2, ref Tmsg.Auth(tag, fid, uname, aname));
Tflush =>
oldtag := (int f[H+1] << 8) | int f[H];
return (H+TAG, ref Tmsg.Flush(tag, oldtag));
Tattach =>
afid := g32(f, H+FID);
(uname, o1) := gstring(f, H+2*FID);
(aname, o2) := gstring(f, o1);
if(o2 <= 0)
break;
return (o2, ref Tmsg.Attach(tag, fid, afid, uname, aname));
Twalk =>
newfid := g32(f, H+FID);
n := (int f[H+2*FID+1] << 8) | int f[H+2*FID];
if(n > MAXWELEM)
break;
o := H+2*FID+LEN;
names: array of string = nil;
if(n > 0){
names = array[n] of string;
for(i:=0; i<n; i++){
(names[i], o) = gstring(f, o);
if(o <= 0)
break Decode;
}
}
return (o, ref Tmsg.Walk(tag, fid, newfid, names));
Topen =>
return (H+FID+BIT8SZ, ref Tmsg.Open(tag, fid, int f[H+FID]));
Tcreate =>
(name, o) := gstring(f, H+FID);
if(o <= 0 || o+BIT32SZ+BIT8SZ > len f)
break;
perm := g32(f, o);
o += BIT32SZ;
mode := int f[o++];
return (o, ref Tmsg.Create(tag, fid, name, perm, mode));
Tread =>
offset := g64(f, H+FID);
count := g32(f, H+FID+OFFSET);
return (H+FID+OFFSET+COUNT, ref Tmsg.Read(tag, fid, offset, count));
Twrite =>
offset := g64(f, H+FID);
count := g32(f, H+FID+OFFSET);
O: con H+FID+OFFSET+COUNT;
if(count > len f-O)
break;
data := f[O:O+count];
return (O+count, ref Tmsg.Write(tag, fid, offset, data));
Tclunk =>
return (H+FID, ref Tmsg.Clunk(tag, fid));
Tremove =>
return (H+FID, ref Tmsg.Remove(tag, fid));
Tstat =>
return (H+FID, ref Tmsg.Stat(tag, fid));
Twstat =>
n := int (f[H+FID+1]<<8) | int f[H+FID];
if(len f < H+FID+LEN+n)
break;
(ds, stat) := unpackdir(f[H+FID+LEN:]);
if(ds != n){
sys->print("Styx->Tmsg.unpack: wstat count: %d/%d\n", ds, n); # temporary
break;
}
return (H+FID+LEN+n, ref Tmsg.Wstat(tag, fid, stat));
}
return (-1, nil); # illegal
}
tmsgname := array[] of {
tagof Tmsg.Readerror => "Readerror",
tagof Tmsg.Version => "Version",
tagof Tmsg.Auth => "Auth",
tagof Tmsg.Attach => "Attach",
tagof Tmsg.Flush => "Flush",
tagof Tmsg.Walk => "Walk",
tagof Tmsg.Open => "Open",
tagof Tmsg.Create => "Create",
tagof Tmsg.Read => "Read",
tagof Tmsg.Write => "Write",
tagof Tmsg.Clunk => "Clunk",
tagof Tmsg.Stat => "Stat",
tagof Tmsg.Remove => "Remove",
tagof Tmsg.Wstat => "Wstat",
};
Tmsg.text(t: self ref Tmsg): string
{
if(t == nil)
return "nil";
s := sys->sprint("Tmsg.%s(%ud", tmsgname[tagof t], t.tag);
pick m:= t {
* =>
return s + ",ILLEGAL)";
Readerror =>
return s + sys->sprint(",\"%s\")", m.error);
Version =>
return s + sys->sprint(",%d,\"%s\")", m.msize, m.version);
Auth =>
return s + sys->sprint(",%ud,\"%s\",\"%s\")", m.afid, m.uname, m.aname);
Flush =>
return s + sys->sprint(",%ud)", m.oldtag);
Attach =>
return s + sys->sprint(",%ud,%ud,\"%s\",\"%s\")", m.fid, m.afid, m.uname, m.aname);
Walk =>
s += sys->sprint(",%ud,%ud", m.fid, m.newfid);
if(len m.names != 0){
s += ",array[] of {";
for(i := 0; i < len m.names; i++){
c := ",";
if(i == 0)
c = "";
s += sys->sprint("%s\"%s\"", c, m.names[i]);
}
s += "}";
}else
s += ",nil";
return s + ")";
Open =>
return s + sys->sprint(",%ud,%d)", m.fid, m.mode);
Create =>
return s + sys->sprint(",%ud,\"%s\",8r%uo,%d)", m.fid, m.name, m.perm, m.mode);
Read =>
return s + sys->sprint(",%ud,%bd,%ud)", m.fid, m.offset, m.count);
Write =>
return s + sys->sprint(",%ud,%bd,array[%d] of byte)", m.fid, m.offset, len m.data);
Clunk or
Remove or
Stat =>
return s + sys->sprint(",%ud)", m.fid);
Wstat =>
return s + sys->sprint(",%ud,%s)", m.fid, dir2text(m.stat));
}
}
Tmsg.read(fd: ref Sys->FD, msglim: int): ref Tmsg
{
(msg, err) := readmsg(fd, msglim);
if(err != nil)
return ref Tmsg.Readerror(0, err);
if(msg == nil)
return nil;
(nil, m) := Tmsg.unpack(msg);
if(m == nil)
return ref Tmsg.Readerror(0, "bad 9P T-message format");
return m;
}
rtag2type := array[] of {
tagof Rmsg.Version => Rversion,
tagof Rmsg.Auth => Rauth,
tagof Rmsg.Error => Rerror,
tagof Rmsg.Flush => Rflush,
tagof Rmsg.Attach => Rattach,
tagof Rmsg.Walk => Rwalk,
tagof Rmsg.Open => Ropen,
tagof Rmsg.Create => Rcreate,
tagof Rmsg.Read => Rread,
tagof Rmsg.Write => Rwrite,
tagof Rmsg.Clunk => Rclunk,
tagof Rmsg.Remove => Rremove,
tagof Rmsg.Stat => Rstat,
tagof Rmsg.Wstat => Rwstat,
};
Rmsg.mtype(r: self ref Rmsg): int
{
return rtag2type[tagof r];
}
Rmsg.packedsize(r: self ref Rmsg): int
{
mtype := rtag2type[tagof r];
if(mtype <= 0)
return 0;
ml := hdrlen[mtype];
pick m := r {
Version =>
ml += utflen(m.version);
Error =>
ml += utflen(m.ename);
Walk =>
ml += QID*len m.qids;
Read =>
ml += len m.data;
Stat =>
ml += packdirsize(m.stat);
}
return ml;
}
Rmsg.pack(r: self ref Rmsg): array of byte
{
if(r == nil)
return nil;
ps := r.packedsize();
if(ps <= 0)
return nil;
d := array[ps] of byte;
d[0] = byte ps;
d[1] = byte (ps>>8);
d[2] = byte (ps>>16);
d[3] = byte (ps>>24);
d[4] = byte rtag2type[tagof r];
d[5] = byte r.tag;
d[6] = byte (r.tag >> 8);
pick m := r {
Version =>
p32(d, H, m.msize);
pstring(d, H+BIT32SZ, m.version);
Auth =>
pqid(d, H, m.aqid);
Flush or
Clunk or
Remove or
Wstat =>
; # nothing more required
Error =>
pstring(d, H, m.ename);
Attach =>
pqid(d, H, m.qid);
Walk =>
n := len m.qids;
d[H] = byte n;
d[H+1] = byte (n>>8);
o := H+LEN;
for(i:=0; i<n; i++){
pqid(d, o, m.qids[i]);
o += QID;
}
Create or
Open =>
pqid(d, H, m.qid);
p32(d, H+QID, m.iounit);
Read =>
v := len m.data;
d[H] = byte v;
d[H+1] = byte (v>>8);
d[H+2] = byte (v>>16);
d[H+3] = byte (v>>24);
d[H+4:] = m.data;
Write =>
v := m.count;
d[H] = byte v;
d[H+1] = byte (v>>8);
d[H+2] = byte (v>>16);
d[H+3] = byte (v>>24);
Stat =>
stat := packdir(m.stat);
v := len stat;
d[H] = byte v;
d[H+1] = byte (v>>8);
d[H+2:] = stat; # should avoid copy?
* =>
raise sys->sprint("assertion: Styx->Rmsg.pack: missed case: tag %d", tagof r);
}
return d;
}
Rmsg.unpack(f: array of byte): (int, ref Rmsg)
{
if(len f < H)
return (0, nil);
size := (int f[1] << 8) | int f[0];
size |= ((int f[3] << 8) | int f[2]) << 16; # size includes itself
if(len f != size){
if(len f < size)
return (0, nil); # need more data
f = f[0:size]; # trim to exact length
}
mtype := int f[4];
if(mtype >= len hdrlen || (mtype&1) == 0 || size < hdrlen[mtype])
return (-1, nil);
tag := (int f[6] << 8) | int f[5];
# return out of each case body for a legal message;
# break out of the case for an illegal one
case mtype {
* =>
sys->print("Styx->Rmsg.unpack: bad type %d\n", mtype); # temporary
Rversion =>
msize := g32(f, H);
(version, o) := gstring(f, H+BIT32SZ);
if(o <= 0)
break;
return (o, ref Rmsg.Version(tag, msize, version));
Rauth =>
return (H+QID, ref Rmsg.Auth(tag, gqid(f, H)));
Rflush =>
return (H, ref Rmsg.Flush(tag));
Rerror =>
(ename, o) := gstring(f, H);
if(o <= 0)
break;
return (o, ref Rmsg.Error(tag, ename));
Rclunk =>
return (H, ref Rmsg.Clunk(tag));
Rremove =>
return (H, ref Rmsg.Remove(tag));
Rwstat=>
return (H, ref Rmsg.Wstat(tag));
Rattach =>
return (H+QID, ref Rmsg.Attach(tag, gqid(f, H)));
Rwalk =>
nqid := (int f[H+1] << 8) | int f[H];
if(len f < H+LEN+nqid*QID)
break;
o := H+LEN;
qids := array[nqid] of Sys->Qid;
for(i:=0; i<nqid; i++){
qids[i] = gqid(f, o);
o += QID;
}
return (o, ref Rmsg.Walk(tag, qids));
Ropen =>
return (H+QID+COUNT, ref Rmsg.Open(tag, gqid(f, H), g32(f, H+QID)));
Rcreate=>
return (H+QID+COUNT, ref Rmsg.Create(tag, gqid(f, H), g32(f, H+QID)));
Rread =>
count := g32(f, H);
if(len f < H+COUNT+count)
break;
data := f[H+COUNT:H+COUNT+count];
return (H+COUNT+count, ref Rmsg.Read(tag, data));
Rwrite =>
return (H+COUNT, ref Rmsg.Write(tag, g32(f, H)));
Rstat =>
n := (int f[H+1] << 8) | int f[H];
if(len f < H+LEN+n)
break;
(ds, d) := unpackdir(f[H+LEN:]);
if(ds <= 0)
break;
if(ds != n){
sys->print("Styx->Rmsg.unpack: stat count: %d/%d\n", ds, n); # temporary
break;
}
return (H+LEN+n, ref Rmsg.Stat(tag, d));
}
return (-1, nil); # illegal
}
rmsgname := array[] of {
tagof Rmsg.Version => "Version",
tagof Rmsg.Auth => "Auth",
tagof Rmsg.Attach => "Attach",
tagof Rmsg.Error => "Error",
tagof Rmsg.Flush => "Flush",
tagof Rmsg.Walk => "Walk",
tagof Rmsg.Create => "Create",
tagof Rmsg.Open => "Open",
tagof Rmsg.Read => "Read",
tagof Rmsg.Write => "Write",
tagof Rmsg.Clunk => "Clunk",
tagof Rmsg.Remove => "Remove",
tagof Rmsg.Stat => "Stat",
tagof Rmsg.Wstat => "Wstat",
};
Rmsg.text(r: self ref Rmsg): string
{
if(sys == nil)
sys = load Sys Sys->PATH;
if(r == nil)
return "nil";
s := sys->sprint("Rmsg.%s(%ud", rmsgname[tagof r], r.tag);
pick m := r {
* =>
return s + "ERROR)";
Readerror =>
return s + sys->sprint(",\"%s\")", m.error);
Version =>
return s + sys->sprint(",%d,\"%s\")", m.msize, m.version);
Auth =>
return s+sys->sprint(",%s)", qid2text(m.aqid));
Error =>
return s+sys->sprint(",\"%s\")", m.ename);
Flush or
Clunk or
Remove or
Wstat =>
return s+")";
Attach =>
return s+sys->sprint(",%s)", qid2text(m.qid));
Walk =>
s += ",array[] of {";
for(i := 0; i < len m.qids; i++){
c := "";
if(i != 0)
c = ",";
s += sys->sprint("%s%s", c, qid2text(m.qids[i]));
}
return s+"})";
Create or
Open =>
return s+sys->sprint(",%s,%d)", qid2text(m.qid), m.iounit);
Read =>
return s+sys->sprint(",array[%d] of byte)", len m.data);
Write =>
return s+sys->sprint(",%d)", m.count);
Stat =>
return s+sys->sprint(",%s)", dir2text(m.stat));
}
}
Rmsg.read(fd: ref Sys->FD, msglim: int): ref Rmsg
{
(msg, err) := readmsg(fd, msglim);
if(err != nil)
return ref Rmsg.Readerror(0, err);
if(msg == nil)
return nil;
(nil, m) := Rmsg.unpack(msg);
if(m == nil)
return ref Rmsg.Readerror(0, "bad 9P R-message format");
return m;
}
dir2text(d: Sys->Dir): string
{
return sys->sprint("Dir(\"%s\",\"%s\",\"%s\",%s,8r%uo,%d,%d,%bd,16r%ux,%d)",
d.name, d.uid, d.gid, qid2text(d.qid), d.mode, d.atime, d.mtime, d.length, d.dtype, d.dev);
}
qid2text(q: Sys->Qid): string
{
return sys->sprint("Qid(16r%ubx,%d,16r%.2ux)", q.path, q.vers, q.qtype);
}
readmsg(fd: ref Sys->FD, msglim: int): (array of byte, string)
{
if(msglim <= 0)
msglim = MAXRPC;
sbuf := array[BIT32SZ] of byte;
if((n := sys->readn(fd, sbuf, BIT32SZ)) != BIT32SZ){
if(n == 0)
return (nil, nil);
return (nil, sys->sprint("%r"));
}
ml := (int sbuf[1] << 8) | int sbuf[0];
ml |= ((int sbuf[3] << 8) | int sbuf[2]) << 16;
if(ml <= BIT32SZ)
return (nil, "invalid 9P message size");
if(ml > msglim)
return (nil, "9P message longer than agreed");
buf := array[ml] of byte;
buf[0:] = sbuf;
if((n = sys->readn(fd, buf[BIT32SZ:], ml-BIT32SZ)) != ml-BIT32SZ){
if(n == 0)
return (nil, "9P message truncated");
return (nil, sys->sprint("%r"));
}
return (buf, nil);
}
istmsg(f: array of byte): int
{
if(len f < H)
return -1;
return (int f[BIT32SZ] & 1) == 0;
}
compatible(t: ref Tmsg.Version, msize: int, version: string): (int, string)
{
if(version == nil)
version = VERSION;
if(t.msize < msize)
msize = t.msize;
v := t.version;
if(len v < 2 || v[0:2] != "9P")
return (msize, "unknown");
for(i:=2; i<len v; i++)
if((c := v[i]) == '.'){
v = v[0:i];
break;
}else if(!(c >= '0' && c <= '9'))
return (msize, "unknown"); # fussier than Plan 9
if(v < VERSION)
return (msize, "unknown");
if(v < version)
version = v;
return (msize, version);
}
# only here to support an implementation of this module that talks the previous version of Styx
write(fd: ref Sys->FD, buf: array of byte, nb: int): int
{
return sys->write(fd, buf, nb);
}