ref: 44cb92becf1a420e6f72f4f1637fd0914c5cd46d
parent: 7d6bcb1b92b93282003c59c4dc416814ecbf0414
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Wed Apr 3 09:45:54 EDT 2019
sshnet: pass on open failure error message, simplify 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().
--- a/sys/src/cmd/sshnet.c
+++ b/sys/src/cmd/sshnet.c
@@ -46,6 +46,7 @@
Dialing,
Established,
Teardown,
+ Finished,
};
char *statestr[] = {@@ -53,6 +54,7 @@
"Dialing",
"Established",
"Teardown",
+ "Finished",
};
struct Client
@@ -61,7 +63,6 @@
int state;
int num;
int servernum;
- int sentclose;
char *connect;
int sendpkt;
@@ -120,7 +121,6 @@
int sshfd;
int localport;
char localip[] = "::";
-char Ehangup[] = "hangup on network connection";
int
vpack(uchar *p, int n, char *fmt, va_list a)
@@ -434,26 +434,10 @@
}
void
-dialedclient(Client *c)
+hangupclient(Client *c, char *err)
{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)
-{- Req *r;
-
c->eof = 1;
c->recvwin = 0;
c->sendwin = 0;
@@ -460,22 +444,17 @@
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 @@
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 @@
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 @@
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 @@
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);
--
⑨