ref: 98631784ffd6f9a1f303314cf75e09e54febe4a2
dir: /msg.c/
#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"
enum /* Rdpnego.type */
{
Tnego= 1,
Rnego= 2,
};
typedef struct Rdpnego Rdpnego;
struct Rdpnego
{
int type;
int flags;
int proto;
};
static int
putnego(uchar* b, uint nb, Rdpnego* m)
{
int len;
len = 8;
if(nb < 8){
werrstr(Esmall);
return -1;
}
b[0] = m->type;
b[1] = m->flags;
PSHORT(b+2, len);
PLONG(b+4, m->proto);
return len;
}
static int
getnego(Rdpnego* m, uchar* b, uint nb)
{
int len;
if(nb < 8){
werrstr(Eshort);
return -1;
}
m->type = b[0];
m->flags = b[1];
len = GSHORT(b+2);
m->proto = GLONG(b+4);
if(len != 8){
werrstr("bad length in RDP Nego Response");
return -1;
}
return len;
}
int
sizesechdr(int secflags)
{
if(secflags&Scrypt)
return 12; // flags[4] mac[8]
else if(secflags)
return 4; // flags[4]
return 0;
}
uchar*
txprep(uchar* buf, int nb, int ndata, int chanid, int mcsuid, int secflags)
{
int n, len, shdsize;
uchar *p, *ep;
if(chanid==0)
chanid = GLOBALCHAN;
shdsize = sizesechdr(secflags);
len = TPDATAFIXLEN+8+shdsize+ndata;
if(len>nb){
werrstr("%s: provided %d, need %d, data %d", Esmall, nb, len, ndata);
return nil;
}
ep = buf+len;
ndata = len-TPDATAFIXLEN;
n = mktpdat(buf, nb, ndata);
if(n < 0)
sysfatal("mktpdat: %r");
p = buf+TPDATAFIXLEN;
ndata -= 8;
if(putmsdr(p, ep-p, ndata, chanid, mcsuid) < 0)
sysfatal("putmsdr: %r");
p += 8;
if(shdsize > 0)
PLONG(p, secflags);
return p + shdsize;
}
int
putmsg(uchar* b, uint nb, Msg* m)
{
int n, nld, len;
uchar *p, *ep, *q;
Rdpnego neg;
switch(m->type){
case Xconnect:
/* 5.4.2.1 Negotiation-Based Approach */
nld = 20+8;
n = mktpcr(b, nb, nld);
if(n < 0)
return -1;
p = b+n-nld;
ep = b+n;
memcpy(p, "Cookie: mstshash=x\r\n", 20);
neg = (Rdpnego){Tnego, 0, m->negproto};
if(putnego(p+20, ep-p, &neg) != 8){
werrstr("pnego failed: %r");
return -1;
}
return n;
case Xhangup:
return mktpdr(b, nb, 0);
case Mattach:
n = mktpdat(b, nb, 1);
if(n < 0)
return -1;
b[TPDATAFIXLEN] = (Maur<<2);
return n;
case Mjoin:
n = mktpdat(b, nb, 5);
if(n < 0)
return -1;
p = b+TPDATAFIXLEN;
p[0] = (Mcjr << 2);
PSHORTB(p+1, m->mcsuid);
PSHORTB(p+3, m->chanid);
return n;
case Merectdom:
n = mktpdat(b, nb, 5);
if(n < 0)
return -1;
p = b+TPDATAFIXLEN;
p[0] = (Medr << 2);
PSHORTB(p+1, 1);
PSHORTB(p+3, 1);
return n;
case Mconnect:
/* 2.2.1.3 Client MCS Connect Initial PDU with GCC Conference Create Request */
nld = sizegccr(m);
len = mktpdat(b, nb, nld+MCSCIFIXLEN);
if(len < 0){
werrstr("mktpdat: %r");
return -1;
}
p = b+TPDATAFIXLEN;
ep = b+nb;
n = mkmcsci(p, ep-p, nld);
if(n != nld+MCSCIFIXLEN){
werrstr("mkmcsci: %r");
return -1;
}
n = putgccr(p+MCSCIFIXLEN, nld, m);
if(n != nld){
werrstr("putgccr: %r");
return -1;
}
return len;
case Dclientinfo:
/* 2.2.1.11 Client Info PDU */
return putclientinfo(b, nb, m);
case Mactivated:
/* 2.2.1.13.2 Client Confirm Active PDU */
return putconfirmactive(b, nb, m);
case Mvchan:
nld = m->ndata+8;
p = txprep(b, nb, nld, m->chanid, m->originid, 0);
if(p == nil)
return -1;
PLONG(p+0, m->len);
PLONG(p+4, m->flags);
memcpy(p+8, m->data, m->ndata);
len = p+nld-b;
return len;
case Async:
/* 2.2.1.14 Client Synchronize PDU */
nld = 4+SCDSIZE;
if((p = txprep(b, nb, nld, 0, m->originid, 0)) == nil)
return -1;
len = p+nld-b;
q = putsdh(p, p+nld, nld, ADsync, m->originid, m->shareid);
PSHORT(q+0, 1); // sync message type
PSHORT(q+2, m->mcsuid); // target MCS userId
return len;
case Actl:
/* 2.2.1.15 Control PDU */
nld = 8+SCDSIZE;
if((p = txprep(b, nb, nld, 0, m->originid, 0)) == nil)
return -1;
len = p+nld-b;
q = putsdh(p, p+nld, nld, ADctl, m->originid, m->shareid);
/* action[2] grantId[2] controlId[2] */
PSHORT(q+0, m->action);
PSHORT(q+2, 0);
PLONG(q+4, 0);
return len;
case Afontls:
/* 2.2.1.18 Client Font List PDU */
nld = 8+SCDSIZE;
if((p = txprep(b, nb, nld, 0, m->originid, 0)) == nil)
return -1;
len = p+nld-b;
q = putsdh(p, p+nld, nld, ADfontlist, m->originid, m->shareid);
PSHORT(q+0, 0); // numberFonts
PSHORT(q+2, 0); // totalNumFonts
PSHORT(q+4, 2+1); // listFlags: 1=first, 2=last
PSHORT(q+6, 50); // entrySize
return len;
case Ainput:
/* 2.2.8.1.1.3.1.1 Slow-Path Input Event (TS_INPUT_EVENT) */
nld = 16+SCDSIZE;
if((p = txprep(b, nb, nld, 0, m->originid, 0)) == nil)
return -1;
len = p+nld-b;
q = putsdh(p, p+nld, nld, ADinput, m->originid, m->shareid);
PSHORT(q+0, 1); /* numEvents */
PSHORT(q+2, 0);
PLONG(q+4, m->msec);
PSHORT(q+8, m->mtype);
PSHORT(q+10, m->flags);
PSHORT(q+12, m->iarg[0]);
PSHORT(q+14, m->iarg[1]);
return len;
case Lreq:
case Lnolicense:
if((nld = sizelicensemsg(m)) < 0)
return -1;
if((p = txprep(b, nb, nld, 0, m->originid, Slicensepk)) == nil)
return -1;
len = p+nld-b;
if(putlicensemsg(p, nld, m) != nld){
werrstr("putlicensemsg: %r");
return -1;
}
return len;
case Dsupress:
/* 2.2.11.3 Suppress Output PDU */
nld = (m->allow?12:4)+SCDSIZE;
if((p = txprep(b, nb, nld, 0, m->originid, 0)) == nil)
return -1;
len = p-b+nld;
q = putsdh(p, p+nld, nld, ADsupress, m->originid, m->shareid);
q[0] = (m->allow?1:0);
memset(q+1, 3, 0);
if(m->allow){
PSHORT(q+4, 0); // left
PSHORT(q+6, 0); // top
PSHORT(q+8, m->xsz-1); // right
PSHORT(q+10, m->ysz-1); // bottom
}
return len;
default:
werrstr("putmsg: unsupported type");
return 0;
}
};
int
getmsg(Msg* m, uchar* b, uint nb)
{
uchar *p, *ep;
int type, mtag, btag, mr, secflg, sctlver;
Rdpnego neg;
p = b;
ep = b+nb;
if(istpkt(p, ep) == 0){
/*
* 2.2.9.1.2 Server Fast-Path Update PDU
* enabled with CanFastpath in General Capability Set
*/
if(p[0]&(1<<7)){
werrstr("legacy encryption in a Fast-Path PDU");
return -1;
}
if(p[1]&(1<<7))
p += 3;
else
p += 2;
m->type = Aupdate;
m->data = p;
m->ndata = ep-p;
m->getshare = getshareF;
return nb;
}
type = tptype(b, b+nb);
switch(type){
default:
werrstr("unknown TPDU type %d", type);
return -1;
case ConCfrm:
/* 5.4.2.1 Negotiation-Based Approach */
m->type = Xconnected;
m->negproto = 0;
if((p = tpdat(p, ep)) != nil && getnego(&neg, p, ep-p))
if(neg.type == Rnego)
m->negproto = neg.proto;
return nb;
case Data:
p = tpdat(p, ep);
if(p+2 > ep){
werrstr(Eshort);
return -1;
}
/* try ASN.1 PER: DomainMCSPDU are encoded this way */
mtag = p[0]>>2;
switch(mtag){
default:
werrstr("unknown MCS tag %d", mtag);
return -1;
case Mauc:
m->type = Mattached;
m->mcsuid = 0;
mr = p[1];
if(mr != 0){
werrstr("Mauc error result: %d", mr);
return -1;
}
if((p[0])&2){
if(p+4 > ep){
werrstr(Eshort);
return -1;
}
m->mcsuid = GSHORTB(p+2);
}
return nb;
case Mcjc:
m->type = Mjoined;
mr = p[1];
if(mr != 0){
werrstr("Mcjc error result: %d", mr);
return -1;
}
return nb;
case Mdpu:
m->type = Mclosing;
return nb;
case Msdi:
m->chanid = mcschan(b, b+nb);
if(m->chanid < 0){
werrstr("%d: bad MCS channel id", m->chanid);
return -1;
}
p = mcsdat(b, b+nb);
if(p == nil)
return -1;
if(m->chanid != GLOBALCHAN){
m->type = Mvchan;
m->len = GLONG(p+0);
m->flags = GLONG(p+4);
m->data = p+8;
m->ndata = ep-p-8;
if(m->len > 8*1024*1024){
werrstr("bad length in virtual channel PDU header");
return -1;
}
return nb;
}
if(isflowpdu(p,ep)){
m->type = Aflow;
return nb;
}
secflg = GSHORT(p);
sctlver = GSHORT(p+2)>>4;
if(secflg&Slicensepk && sctlver != 1)
return getlicensemsg(m, p+4, ep-(p+4));
m->type = Aupdate;
m->data = p;
m->ndata = ep-p;
m->getshare = getshareT;
return nb;
case 31:
/* try ANS.1 BER: T.125 ConnectMCSPDU are encoded this way */
gbtag(p, ep, &btag);
switch(btag){
case Mcr:
return getmcr(m, p, ep-p);
default:
werrstr("unknown MCS BER tag %d", btag);
return -1;
}
}
}
};
int
readmsg(Rdp* c, Msg* m)
{
uchar* buf;
int fd, n;
uint nb;
fd = c->fd;
buf = c->rbuf;
nb = sizeof c->rbuf;
if((n = readpdu(fd, buf, nb)) < 0 || getmsg(m, buf, n) <= 0)
return -1;
if(m->type == Mclosing)
return 0;
return n;
}
int
writemsg(Rdp* c, Msg* m)
{
uchar buf[MAXTPDU];
int fd, n;
fd = c->fd;
if((n = putmsg(buf, sizeof buf, m)) < 0 || write(fd, buf, n) != n)
return -1;
return n;
}