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sshnet: pass on open failure error message, simplify

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return the error message from MSG_CHANNEL_OPEN_FAILURE
in the "connect" control write.

use a extra state "Finished" to distinguish server from client
initiated teardown. that way we do not need to track if we
send the MSG_CHANNEL_CLOSE message in closeclient(). this way
we also cannot be fooled by misbehaving server.

simplify hangupclient() by removing state transitions and doing
them in the caller explicitely. that way we can use hangupclient()
instead of dialedclient().
This commit is contained in:
cinap_lenrek 2019-04-03 13:45:54 +02:00
parent a278545e3c
commit 2251ef7a32
1 changed files with 40 additions and 41 deletions
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81
sys/src/cmd/sshnet.c
View file

@ -46,6 +46,7 @@ enum
Dialing,
Established,
Teardown,
Finished,
};
char *statestr[] = {
@ -53,6 +54,7 @@ char *statestr[] = {
"Dialing",
"Established",
"Teardown",
"Finished",
};
struct Client
@ -61,7 +63,6 @@ struct Client
int state;
int num;
int servernum;
int sentclose;
char *connect;
int sendpkt;
@ -120,7 +121,6 @@ char *mtpt;
int sshfd;
int localport;
char localip[] = "::";
char Ehangup[] = "hangup on network connection";
int
vpack(uchar *p, int n, char *fmt, va_list a)
@ -434,23 +434,7 @@ findreq(Client *c, Req *r)
}
void
dialedclient(Client *c)
{
Req *r;
if(r=c->wq){
if(r->aux != nil)
sysfatal("more than one outstanding dial request (BUG)");
if(c->state == Established)
respond(r, nil);
else
respond(r, "connect failed");
}
c->wq = nil;
}
void
hangupclient(Client *c)
hangupclient(Client *c, char *err)
{
Req *r;
@ -460,22 +444,17 @@ hangupclient(Client *c)
while((r = c->wq) != nil){
c->wq = r->aux;
r->aux = nil;
respond(r, Ehangup);
respond(r, err);
}
if(c->state == Established){
c->state = Teardown;
matchrmsgs(c);
return;
}
c->state = Closed;
matchrmsgs(c);
}
void
teardownclient(Client *c)
{
hangupclient(c);
if(c->sentclose++ == 0)
sendmsg(pack(nil, "bu", MSG_CHANNEL_CLOSE, c->servernum));
c->state = Teardown;
hangupclient(c, "i/o on hungup channel");
sendmsg(pack(nil, "bu", MSG_CHANNEL_CLOSE, c->servernum));
}
void
@ -485,14 +464,21 @@ closeclient(Client *c)
if(--c->ref)
return;
if(c->state >= Established)
switch(c->state){
case Established:
teardownclient(c);
break;
case Finished:
c->state = Closed;
sendmsg(pack(nil, "bu", MSG_CHANNEL_CLOSE, c->servernum));
break;
}
while((m = c->mq) != nil){
c->mq = m->link;
free(m);
}
}
void
sshreadproc(void*)
{
@ -813,9 +799,7 @@ ctlwrite(Req *r, Client *c)
nf = getfields(f[1], f, nelem(f), 0, "!");
if(nf != 2)
goto Badarg;
c->eof = 0;
c->sendwin = MaxPacket;
c->recvwin = WinPackets * MaxPacket;
c->recvwin = WinPackets*MaxPacket;
c->recvacc = 0;
c->state = Dialing;
queuewreq(c, r);
@ -1074,8 +1058,17 @@ handlemsg(Msg *m)
if(unpack(m, "_u", &chan) < 0)
break;
c = getclient(chan);
if(c != nil && c->state >= Established)
hangupclient(c);
if(c == nil)
break;
switch(c->state){
case Established:
c->state = Finished;
hangupclient(c, "connection closed");
break;
case Teardown:
c->state = Closed;
break;
}
break;
case MSG_CHANNEL_OPEN_CONFIRMATION:
if(unpack(m, "_uuuu", &chan, &n, &win, &pkt) < 0)
@ -1089,25 +1082,31 @@ handlemsg(Msg *m)
break;
if(pkt <= 0 || pkt > MaxPacket)
pkt = MaxPacket;
c->eof = 0;
c->sendpkt = pkt;
c->sendwin = win;
c->servernum = n;
c->sentclose = 0;
c->state = Established;
dialedclient(c);
if(c->wq != nil){
respond(c->wq, nil);
c->wq = nil;
}
break;
case MSG_CHANNEL_OPEN_FAILURE:
if(unpack(m, "_u____s", &chan, &s, &n) < 0)
break;
s = smprint("%.*s", utfnlen(s, n), s);
if(chan == SESSIONCHAN){
sendp(ssherrchan, smprint("%.*s", utfnlen(s, n), s));
sendp(ssherrchan, s);
break;
}
c = getclient(chan);
if(c == nil || c->state != Dialing)
if(c == nil || c->state != Dialing){
free(s);
break;
}
c->state = Closed;
dialedclient(c);
hangupclient(c, s);
break;
}
free(m);