nhyatt/putty-source
1
0
Fork 0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-07-06 05:52:48 -05:00
Code Issues Projects Releases Wiki Activity

SSH port forwarding! How cool is that?

Browse Source 
Only currently works on SSH1; SSH2 should be doable but it's late
and I have other things to do tonight. The Cool Guy award for this
one goes to Nicolas Barry, for doing most of the work and actually
understanding the code he was adding to.

[originally from svn r1176]
This commit is contained in:
Simon Tatham
2001-08-08 20:44:35 +00:00
parent 4d3aad22f5
commit 50766ce729
13 changed files with 738 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

222
ssh.c
View File

@ -196,6 +196,12 @@ extern void x11_close(Socket);
extern void x11_send(Socket, char *, int);
extern void x11_invent_auth(char *, int, char *, int);
extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
extern char *pfd_addforward(char *desthost, int destport, int port);
extern void pfd_close(Socket s);
extern void pfd_send(Socket s, char *data, int len);
extern void pfd_confirm(Socket s);
/*
* Ciphers for SSH2. We miss out single-DES because it isn't
* supported; also 3DES and Blowfish are both done differently from
@ -263,6 +269,7 @@ enum { /* channel types */
CHAN_MAINSESSION,
CHAN_X11,
CHAN_AGENT,
CHAN_SOCKDATA
};
/*
@ -286,9 +293,22 @@ struct ssh_channel {
struct ssh_x11_channel {
Socket s;
} x11;
struct ssh_pfd_channel {
Socket s;
} pfd;
} u;
};
/*
* 2-3-4 tree storing remote->local port forwardings (so we can
* reject any attempt to open a port we didn't explicitly ask to
* have forwarded).
*/
struct ssh_rportfwd {
unsigned port;
char host[256];
};
struct Packet {
long length;
int type;
@ -330,6 +350,8 @@ static int ssh_echoing, ssh_editing;
static tree234 *ssh_channels; /* indexed by local id */
static struct ssh_channel *mainchan; /* primary session channel */
static tree234 *ssh_rportfwds;
static enum {
SSH_STATE_PREPACKET,
SSH_STATE_BEFORE_SIZE,
@ -393,6 +415,18 @@ static int ssh_channelfind(void *av, void *bv)
return 0;
}
static int ssh_rportcmp(void *av, void *bv)
{
struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
int i;
if ( (i = strcmp(a->host, b->host)) != 0)
return i < 0 ? -1 : +1;
if (a->port > b->port)
return +1;
return 0;
}
static int alloc_channel_id(void)
{
const unsigned CHANNEL_NUMBER_OFFSET = 256;
@ -2263,7 +2297,10 @@ void sshfwd_close(struct ssh_channel *c)
c->closes = 1;
if (c->type == CHAN_X11) {
c->u.x11.s = NULL;
logevent("X11 connection terminated");
logevent("Forwarded X11 connection terminated");
} else if (c->type == CHAN_SOCKDATA) {
c->u.pfd.s = NULL;
logevent("Forwarded port closed");
}
}
}
@ -2337,6 +2374,68 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
}
}
{
char type, *e;
int n;
int sport,dport;
char sports[256], dports[256], host[256];
char buf[1024];
ssh_rportfwds = newtree234(ssh_rportcmp);
/* Add port forwardings. */
e = cfg.portfwd;
while (*e) {
type = *e++;
n = 0;
while (*e && *e != '\t')
sports[n++] = *e++;
sports[n] = 0;
if (*e == '\t')
e++;
n = 0;
while (*e && *e != ':')
host[n++] = *e++;
host[n] = 0;
if (*e == ':')
e++;
n = 0;
while (*e)
dports[n++] = *e++;
dports[n] = 0;
e++;
dport = atoi(dports);
sport = atoi(sports);
if (sport && dport) {
if (type == 'L') {
pfd_addforward(host, dport, sport);
sprintf(buf, "Local port %d forwarding to %s:%d",
sport, host, dport);
logevent(buf);
} else {
struct ssh_rportfwd *pf;
pf = smalloc(sizeof(*pf));
strcpy(pf->host, host);
pf->port = dport;
if (add234(ssh_rportfwds, pf) != pf) {
sprintf(buf,
"Duplicate remote port forwarding to %s:%s",
host, dport);
logevent(buf);
} else {
sprintf(buf, "Requesting remote port %d forward to %s:%d",
sport, host, dport);
logevent(buf);
send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
PKT_INT, sport,
PKT_STR, host,
PKT_INT, dport,
PKT_END);
}
}
}
}
}
if (!cfg.nopty) {
send_packet(SSH1_CMSG_REQUEST_PTY,
PKT_STR, cfg.termtype,
@ -2460,6 +2559,73 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
PKT_INT, c->remoteid, PKT_INT, c->localid,
PKT_END);
}
} else if (pktin.type == SSH1_MSG_PORT_OPEN) {
/* Remote side is trying to open a channel to talk to a
* forwarded port. Give them back a local channel number. */
struct ssh_channel *c;
struct ssh_rportfwd pf;
int hostsize, port;
char host[256], buf[1024];
char *p, *h, *e;
c = smalloc(sizeof(struct ssh_channel));
hostsize = GET_32BIT(pktin.body+4);
for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
if (h+1 < host+sizeof(host))
*h++ = *p;
*p++;
}
*h = 0;
port = GET_32BIT(p);
strcpy(pf.host, host);
pf.port = port;
if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
sprintf(buf, "Rejected remote port open request for %s:%d",
host, port);
logevent(buf);
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
PKT_INT, GET_32BIT(pktin.body), PKT_END);
} else {
sprintf(buf, "Received remote port open request for %s:%d",
host, port);
logevent(buf);
e = pfd_newconnect(&c->u.pfd.s, host, port, c);
if (e != NULL) {
char buf[256];
sprintf(buf, "Port open failed: %s", e);
logevent(buf);
sfree(c);
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
PKT_INT, GET_32BIT(pktin.body),
PKT_END);
} else {
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
c->type = CHAN_SOCKDATA; /* identify channel type */
add234(ssh_channels, c);
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
PKT_INT, c->remoteid, PKT_INT,
c->localid, PKT_END);
logevent("Forwarded port opened successfully");
}
}
} else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
unsigned int remoteid = GET_32BIT(pktin.body);
unsigned int localid = GET_32BIT(pktin.body+4);
struct ssh_channel *c;
c = find234(ssh_channels, &remoteid, ssh_channelfind);
if (c) {
c->remoteid = localid;
pfd_confirm(c->u.pfd.s);
} else {
sshfwd_close(c);
}
} else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
/* Remote side closes a channel. */
@ -2474,11 +2640,17 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
send_packet(pktin.type, PKT_INT, c->remoteid,
PKT_END);
if ((c->closes == 0) && (c->type == CHAN_X11)) {
logevent("X11 connection closed");
logevent("Forwarded X11 connection terminated");
assert(c->u.x11.s != NULL);
x11_close(c->u.x11.s);
c->u.x11.s = NULL;
}
if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
logevent("Forwarded port closed");
assert(c->u.pfd.s != NULL);
pfd_close(c->u.pfd.s);
c->u.pfd.s = NULL;
}
c->closes |= closetype;
if (c->closes == 3) {
del234(ssh_channels, c);
@ -2497,6 +2669,9 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
case CHAN_X11:
x11_send(c->u.x11.s, p, len);
break;
case CHAN_SOCKDATA:
pfd_send(c->u.pfd.s, p, len);
break;
case CHAN_AGENT:
/* Data for an agent message. Buffer it. */
while (len > 0) {
@ -3976,6 +4151,9 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
case CHAN_X11:
x11_send(c->u.x11.s, data, length);
break;
case CHAN_SOCKDATA:
pfd_send(c->u.pfd.s, data, length);
break;
case CHAN_AGENT:
while (length > 0) {
if (c->u.a.lensofar < 4) {
@ -4059,6 +4237,9 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
sshfwd_close(c);
} else if (c->type == CHAN_AGENT) {
sshfwd_close(c);
} else if (c->type == CHAN_SOCKDATA) {
pfd_close(c->u.pfd.s);
sshfwd_close(c);
}
} else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
unsigned i = ssh2_pkt_getuint32();
@ -4080,6 +4261,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
break;
case CHAN_AGENT:
break;
case CHAN_SOCKDATA:
break;
}
del234(ssh_channels, c);
sfree(c->v2.outbuffer);
@ -4306,6 +4489,39 @@ static void ssh_special(Telnet_Special code)
}
}
void *new_sock_channel(Socket s)
{
struct ssh_channel *c;
c = smalloc(sizeof(struct ssh_channel));
if (c) {
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
c->type = CHAN_SOCKDATA; /* identify channel type */
c->u.pfd.s = s;
add234(ssh_channels, c);
}
return c;
}
void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
{
struct ssh_channel *c = (struct ssh_channel *)channel;
char buf[1024];
sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
logevent(buf);
send_packet(SSH1_MSG_PORT_OPEN,
PKT_INT, c->localid,
PKT_STR, hostname,
PKT_INT, port,
//PKT_STR, org,
PKT_END);
}
static Socket ssh_socket(void)
{
return s;
@ -4334,4 +4550,4 @@ Backend ssh_backend = {
ssh_sendok,
ssh_ldisc,
22
};
};