sshnet: implement listen (port forwarding)

diff --git a/sys/man/4/sshnet b/sys/man/4/sshnet
index f37c4330a482a3628c580adcf6185c09dbf87134..00c766c78ff0775faa4d2ad7da49d15c65865f7a 100644 (file)
--- a/sys/man/4/sshnet
+++ b/sys/man/4/sshnet
@@ -45,8 +45,6 @@ All other arguments are passed to
 as is.
 .SH SOURCE
 .B /sys/src/cmd/sshnet.c
-.SH BUGS
-Incoming connections are not supported.
 .SH "SEE ALSO"
 .IR ssh (1),
 .IR ip (3)

diff --git a/sys/src/cmd/sshnet.c b/sys/src/cmd/sshnet.c
index fd8862ab0ab77410bdebedaec1a60a6706454b6b..5704ccea72417657439d4d9ad846f9a51f1c3cd7 100755 (executable)
--- a/sys/src/cmd/sshnet.c
+++ b/sys/src/cmd/sshnet.c
@@ -26,6 +26,7 @@ enum
        Qlocal,
        Qremote,
        Qstatus,
+       Qlisten,
 };
 
 #define PATH(type, n)          ((type)|((n)<<8))
@@ -44,6 +45,8 @@ enum
 {
        Closed,
        Dialing,
+       Announced,
+       Listen,
        Established,
        Teardown,
        Finished,
@@ -52,6 +55,8 @@ enum
 char *statestr[] = {
        "Closed",
        "Dialing",
+       "Announced",
+       "Listen",
        "Established",
        "Teardown",
        "Finished",
@@ -63,7 +68,10 @@ struct Client
        int state;
        int num;
        int servernum;
-       char *connect;
+
+       int rport, lport;
+       char *rhost;
+       char *lhost;
 
        int sendpkt;
        int sendwin;
@@ -83,6 +91,8 @@ struct Client
 };
 
 enum {
+       MSG_GLOBAL_REQUEST = 80,
+
        MSG_CHANNEL_OPEN = 90,
        MSG_CHANNEL_OPEN_CONFIRMATION,
        MSG_CHANNEL_OPEN_FAILURE,
@@ -119,8 +129,6 @@ int nclient;
 Client **client;
 char *mtpt;
 int sshfd;
-int localport;
-char localip[] = "::";
 
 int
 vpack(uchar *p, int n, char *fmt, va_list a)
@@ -301,6 +309,19 @@ getclient(int num)
        return client[num];
 }
 
+Client*
+getlistener(char *host, int port)
+{
+       int i;
+
+       USED(host);
+       for(i = 0; i < nclient; i++){
+               if(client[i]->state == Listen && client[i]->lport == port)
+                       return client[i];
+       }
+       return nil;
+}
+
 void
 adjustwin(Client *c, int len)
 {
@@ -472,6 +493,16 @@ closeclient(Client *c)
                c->state = Closed;
                sendmsg(pack(nil, "bu", MSG_CHANNEL_CLOSE, c->servernum));
                break;
+       case Announced:
+               sendmsg(pack(nil, "bsbsu", MSG_GLOBAL_REQUEST,
+                       "cancel-tcpip-forward", 20,
+                       0,
+                       c->lhost, strlen(c->lhost),
+                       c->lport));
+               /* wet floor */
+       case Listen:
+               c->state = Closed;
+               break;
        }
        while((m = c->mq) != nil){
                c->mq = m->link;
@@ -514,6 +545,7 @@ Tab tab[] =
        "local",        0444,
        "remote",       0444,
        "status",       0444,
+       "listen",       0666,
 };
 
 static void
@@ -768,7 +800,7 @@ static void
 ctlwrite(Req *r, Client *c)
 {
        char *f[3], *s;
-       int nf;
+       int nf, port;
 
        s = emalloc9p(r->ifcall.count+1);
        r->ofcall.count = r->ifcall.count;
@@ -790,15 +822,18 @@ ctlwrite(Req *r, Client *c)
                teardownclient(c);
                respond(r, nil);
        }else if(strcmp(f[0], "connect") == 0){
-               if(c->state != Closed)
+               if(nf != 2 || c->state != Closed)
                        goto Badarg;
-               if(nf != 2)
+               if(getfields(f[1], f, nelem(f), 0, "!") != 2)
                        goto Badarg;
-               free(c->connect);
-               c->connect = estrdup9p(f[1]);
-               nf = getfields(f[1], f, nelem(f), 0, "!");
-               if(nf != 2)
+               if((port = ndbfindport(f[1])) < 0)
                        goto Badarg;
+               free(c->lhost);
+               c->lhost = estrdup9p("::");
+               c->lport = 0;
+               free(c->rhost);
+               c->rhost = estrdup9p(f[0]);
+               c->rport = port;
                c->recvwin = WinPackets*MaxPacket;
                c->recvacc = 0;
                c->state = Dialing;
@@ -807,8 +842,28 @@ ctlwrite(Req *r, Client *c)
                sendmsg(pack(nil, "bsuuususu", MSG_CHANNEL_OPEN,
                        "direct-tcpip", 12,
                        c->num, c->recvwin, MaxPacket,
-                       f[0], strlen(f[0]), ndbfindport(f[1]),
-                       localip, strlen(localip), localport));
+                       c->rhost, strlen(c->rhost), c->rport,
+                       c->lhost, strlen(c->lhost), c->lport));
+       }else if(strcmp(f[0], "announce") == 0){
+               if(nf != 2 || c->state != Closed)
+                       goto Badarg;
+               if(getfields(f[1], f, nelem(f), 0, "!") != 2)
+                       goto Badarg;
+               if((port = ndbfindport(f[1])) < 0)
+                       goto Badarg;
+               if(strcmp(f[0], "*") == 0)
+                       f[0] = "";
+               free(c->lhost);
+               c->lhost = estrdup9p(f[0]);
+               c->lport = port;
+               free(c->rhost);
+               c->rhost = estrdup9p("::");
+               c->rport = 0;
+               c->state = Announced;
+               sendmsg(pack(nil, "bsbsu", MSG_GLOBAL_REQUEST,
+                       "tcpip-forward", 13, 0,
+                       c->lhost, strlen(c->lhost), c->lport));
+               respond(r, nil);
        }else{
        Badarg:
                respond(r, "bad or inappropriate tcp control message");
@@ -844,11 +899,16 @@ datawrite(Req *r, Client *c)
 }
 
 static void
-localread(Req *r)
+localread(Req *r, Client *c)
 {
-       char buf[128];
+       char buf[128], *s;
 
-       snprint(buf, sizeof buf, "%s!%d\n", localip, localport);
+       s = c->lhost;
+       if(s == nil)
+               s = "::";
+       else if(*s == 0)
+               s = "*";
+       snprint(buf, sizeof buf, "%s!%d\n", s, c->lport);
        readstr(r, buf);
        respond(r, nil);
 }
@@ -856,13 +916,12 @@ localread(Req *r)
 static void
 remoteread(Req *r, Client *c)
 {
-       char *s;
-       char buf[128];
+       char buf[128], *s;
 
-       s = c->connect;
+       s = c->rhost;
        if(s == nil)
-               s = "::!0";
-       snprint(buf, sizeof buf, "%s\n", s);
+               s = "::";
+       snprint(buf, sizeof buf, "%s!%d\n", s, c->rport);
        readstr(r, buf);
        respond(r, nil);
 }
@@ -918,7 +977,7 @@ fsread(Req *r)
                break;
 
        case Qlocal:
-               localread(r);
+               localread(r, client[NUM(path)]);
                break;
 
        case Qremote:
@@ -985,6 +1044,22 @@ fsopen(Req *r)
                r->fid->aux = cs;
                respond(r, nil);
                break;
+       case Qlisten:
+               if(client[NUM(path)]->state != Announced){
+                       respond(r, "not announced");
+                       break;
+               }
+               n = newclient();
+               free(client[n]->lhost);
+               client[n]->lhost = estrdup9p(client[NUM(path)]->lhost);
+               client[n]->lport = client[NUM(path)]->lport;
+               r->fid->qid.path = PATH(Qctl, n);
+               r->ofcall.qid.path = r->fid->qid.path;
+               r->aux = nil;
+               client[n]->wq = r;
+               client[n]->ref++;
+               client[n]->state = Listen;
+               break;
        case Qclone:
                n = newclient();
                path = PATH(Qctl, n);
@@ -1016,9 +1091,9 @@ fsflush(Req *r)
 static void
 handlemsg(Msg *m)
 {
-       int chan, win, pkt, n;
+       int chan, win, pkt, lport, rport, n, ln, rn;
+       char *s, *lhost, *rhost;
        Client *c;
-       char *s;
 
        switch(m->rp[0]){
        case MSG_CHANNEL_WINDOW_ADJUST:
@@ -1109,6 +1184,50 @@ handlemsg(Msg *m)
                }
                free(s);
                break;
+       case MSG_CHANNEL_OPEN:
+               if(unpack(m, "_suuususu", &s, &n, &chan,
+                       &win, &pkt,
+                       &lhost, &ln, &lport,
+                       &rhost, &rn, &rport) < 0)
+                       break;
+               if(n != 15 || strncmp(s, "forwarded-tcpip", 15) != 0){
+                       n = 3, s = "unknown open type";
+               Reject:
+                       sendmsg(pack(nil, "buus", MSG_CHANNEL_OPEN_FAILURE,
+                               chan, n, s, strlen(s)));
+                       break;
+               }
+               lhost = smprint("%.*s", utfnlen(lhost, ln), lhost);
+               rhost = smprint("%.*s", utfnlen(rhost, rn), rhost);
+               c = getlistener(lhost, lport);
+               if(c == nil){
+                       free(lhost);
+                       free(rhost);
+                       n = 2, s = "connection refused";
+                       goto Reject;
+               }
+               free(c->lhost);
+               c->lhost = lhost;
+               c->lport = lport;
+               free(c->rhost);
+               c->rhost = rhost;
+               c->rport = rport;
+               c->servernum = chan;
+               c->recvwin = WinPackets*MaxPacket;
+               c->recvacc = 0;
+               c->eof = 0;
+               c->sendpkt = pkt;
+               c->sendwin = win;
+               c->state = Established;
+               sendmsg(pack(nil, "buuuu", MSG_CHANNEL_OPEN_CONFIRMATION,
+                       c->servernum, c->num, c->recvwin, MaxPacket));
+               if(c->wq == nil){
+                       teardownclient(c);
+                       break;
+               }
+               respond(c->wq, nil);
+               c->wq = nil;
+               break;
        }
        free(m);
 }