(cp)[0] = (value) >> 8, \
(cp)[1] = (value) )
-struct pfwd_queue {
- struct pfwd_queue *next;
- char *buf;
-};
-
struct PFwdPrivate {
const struct plug_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
void *backhandle; /* instance of SSH backend itself */
/* Note that backhandle need not be filled in if c is non-NULL */
Socket s;
- char hostname[128];
int throttled, throttle_override;
- int port;
int ready;
- struct pfwd_queue *waiting;
+ /*
+ * `dynamic' does double duty. It's set to 0 for an ordinary
+ * forwarded port, and nonzero for SOCKS-style dynamic port
+ * forwarding; but it also represents the state of the SOCKS
+ * exchange.
+ */
+ int dynamic;
+ /*
+ * `hostname' and `port' are the real hostname and port, once
+ * we know what we're connecting to; they're unused for this
+ * purpose while conducting a local SOCKS exchange, which means
+ * we can also use them as a buffer and pointer for reading
+ * data from the SOCKS client.
+ */
+ char hostname[256];
+ int port;
+ /*
+ * When doing dynamic port forwarding, we can receive
+ * connection data before we are actually able to send it; so
+ * we may have to temporarily hold some in a dynamically
+ * allocated buffer here.
+ */
+ void *buffer;
+ int buflen;
};
-
static int pfd_closing(Plug plug, char *error_msg, int error_code,
int calling_back)
{
* so if an error occurred on the socket, we just ignore it
* and treat it like a proper close.
*/
- sshfwd_close(pr->c);
+ if (pr->c)
+ sshfwd_close(pr->c);
pfd_close(pr->s);
return 1;
}
static int pfd_receive(Plug plug, int urgent, char *data, int len)
{
struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
+ if (pr->dynamic) {
+ while (len--) {
+ if (pr->port >= lenof(pr->hostname)) {
+ if ((pr->dynamic >> 12) == 4) {
+ /* Send back a SOCKS 4 error before closing. */
+ char data[8];
+ memset(data, 0, sizeof(data));
+ data[1] = 91; /* generic `request rejected' */
+ sk_write(pr->s, data, 8);
+ }
+ pfd_close(pr->s);
+ return 1;
+ }
+ pr->hostname[pr->port++] = *data++;
+
+ /*
+ * Now check what's in the buffer to see if it's a
+ * valid and complete message in the SOCKS exchange.
+ */
+ if ((pr->dynamic == 1 || (pr->dynamic >> 12) == 4) &&
+ pr->hostname[0] == 4) {
+ /*
+ * SOCKS 4.
+ */
+ if (pr->dynamic == 1)
+ pr->dynamic = 0x4000;
+ if (pr->port < 2) continue;/* don't have command code yet */
+ if (pr->hostname[1] != 1) {
+ /* Send back a SOCKS 4 error before closing. */
+ char data[8];
+ memset(data, 0, sizeof(data));
+ data[1] = 91; /* generic `request rejected' */
+ sk_write(pr->s, data, 8);
+ pfd_close(pr->s);
+ return 1;
+ }
+ if (pr->port < 8) continue; /* haven't started username */
+ if (pr->hostname[pr->port-1] != 0)
+ continue; /* haven't _finished_ username */
+ /*
+ * Now we have a full SOCKS 4 request. Check it to
+ * see if it's a SOCKS 4A request.
+ */
+ if (pr->hostname[4] == 0 && pr->hostname[5] == 0 &&
+ pr->hostname[6] == 0 && pr->hostname[7] != 0) {
+ /*
+ * It's SOCKS 4A. So if we haven't yet
+ * collected the host name, we should continue
+ * waiting for data in order to do so; if we
+ * have, we can go ahead.
+ */
+ int len;
+ if (pr->dynamic == 0x4000) {
+ pr->dynamic = 0x4001;
+ continue;
+ }
+ pr->hostname[0] = 0; /* reply version code */
+ pr->hostname[1] = 90; /* request granted */
+ sk_write(pr->s, pr->hostname, 8);
+ pr->port = GET_16BIT_MSB_FIRST(pr->hostname+2);
+ len = strlen(pr->hostname+8);
+ memmove(pr->hostname, pr->hostname + 8 + len + 1,
+ lenof(pr->hostname) - (8 + len + 1));
+ goto connect;
+ } else {
+ /*
+ * It's SOCKS 4, which means we should format
+ * the IP address into the hostname string and
+ * then just go.
+ */
+ pr->hostname[0] = 0; /* reply version code */
+ pr->hostname[1] = 90; /* request granted */
+ sk_write(pr->s, pr->hostname, 8);
+ pr->port = GET_16BIT_MSB_FIRST(pr->hostname+2);
+ sprintf(pr->hostname, "%d.%d.%d.%d",
+ (unsigned char)pr->hostname[4],
+ (unsigned char)pr->hostname[5],
+ (unsigned char)pr->hostname[6],
+ (unsigned char)pr->hostname[7]);
+ goto connect;
+ }
+ }
+
+ if ((pr->dynamic == 1 || (pr->dynamic >> 12) == 5) &&
+ pr->hostname[0] == 5) {
+ /*
+ * SOCKS 5.
+ */
+ if (pr->dynamic == 1)
+ pr->dynamic = 0x5000;
+
+ if (pr->dynamic == 0x5000) {
+ int i, method;
+ char data[2];
+ /*
+ * We're receiving a set of method identifiers.
+ */
+ if (pr->port < 2) continue;/* no method count yet */
+ if (pr->port < 2 + (unsigned char)pr->hostname[1])
+ continue; /* no methods yet */
+ method = 0xFF; /* invalid */
+ for (i = 0; i < (unsigned char)pr->hostname[1]; i++)
+ if (pr->hostname[2+i] == 0) {
+ method = 0;/* no auth */
+ break;
+ }
+ data[0] = 5;
+ data[1] = method;
+ sk_write(pr->s, data, 2);
+ pr->dynamic = 0x5001;
+ pr->port = 0; /* re-empty the buffer */
+ continue;
+ }
+
+ if (pr->dynamic == 0x5001) {
+ int atype, alen;
+ if (pr->port < 6) continue;
+ atype = (unsigned char)pr->hostname[3];
+ if (atype == 1) /* IPv4 address */
+ alen = 4;
+ if (atype == 4) /* IPv6 address */
+ alen = 16;
+ if (atype == 3) /* domain name has leading length */
+ alen = 1 + (unsigned char)pr->hostname[4];
+ if (pr->port < 6 + alen) continue;
+ if (pr->hostname[1] != 1 || pr->hostname[2] != 0) {
+ pr->hostname[1] = 1; /* generic failure */
+ pr->hostname[2] = 0; /* reserved */
+ sk_write(pr->s, pr->hostname, pr->port);
+ pfd_close(pr->s);
+ return 1;
+ }
+ /*
+ * Now we have a viable connect request. Switch
+ * on atype.
+ */
+ pr->port = GET_16BIT_MSB_FIRST(pr->hostname+4+alen);
+ if (atype == 1) {
+ pr->hostname[1] = 0; /* succeeded */
+ sk_write(pr->s, pr->hostname, alen + 6);
+ sprintf(pr->hostname, "%d.%d.%d.%d",
+ (unsigned char)pr->hostname[4],
+ (unsigned char)pr->hostname[5],
+ (unsigned char)pr->hostname[6],
+ (unsigned char)pr->hostname[7]);
+ goto connect;
+ } else if (atype == 3) {
+ pr->hostname[1] = 0; /* succeeded */
+ sk_write(pr->s, pr->hostname, alen + 6);
+ memmove(pr->hostname, pr->hostname + 5, alen-1);
+ pr->hostname[alen-1] = '\0';
+ goto connect;
+ } else {
+ /*
+ * Unknown address type. (FIXME: support IPv6!)
+ */
+ pr->hostname[1] = 8; /* atype not supported */
+ sk_write(pr->s, pr->hostname, pr->port);
+ pfd_close(pr->s);
+ return 1;
+ }
+ }
+ }
+
+ /*
+ * If we get here without either having done `continue'
+ * or `goto connect', it must be because there is no
+ * sensible interpretation of what's in our buffer. So
+ * close the connection rudely.
+ */
+ pfd_close(pr->s);
+ return 1;
+ }
+ return 1;
+
+ /*
+ * We come here when we're ready to make an actual
+ * connection.
+ */
+ connect:
+
+ pr->c = new_sock_channel(pr->backhandle, pr->s);
+ if (pr->c == NULL) {
+ pfd_close(pr->s);
+ return 1;
+ } else {
+ /* asks to forward to the specified host/port for this */
+ ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
+ }
+ pr->dynamic = 0;
+
+ /*
+ * Now freeze the socket until the SSH server confirms the
+ * connection.
+ */
+ sk_set_frozen(pr->s, 1);
+ /*
+ * If there's any data remaining in our current buffer,
+ * save it to be sent on pfd_confirm().
+ */
+ if (len > 0) {
+ pr->buffer = snewn(len, char);
+ memcpy(pr->buffer, data, len);
+ pr->buflen = len;
+ }
+ }
if (pr->ready) {
if (sshfwd_write(pr->c, data, len) > 0) {
pr->throttled = 1;
{
struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
- sshfwd_unthrottle(pr->c, bufsize);
+ if (pr->c)
+ sshfwd_unthrottle(pr->c, bufsize);
}
/*
* Open socket.
*/
pr = snew(struct PFwdPrivate);
+ pr->buffer = NULL;
pr->fn = &fn_table;
pr->throttled = pr->throttle_override = 0;
pr->ready = 1;
org = (struct PFwdPrivate *)p;
pr = snew(struct PFwdPrivate);
+ pr->buffer = NULL;
pr->fn = &fn_table;
pr->c = NULL;
return err != NULL;
}
- pr->c = new_sock_channel(org->backhandle, s);
+ sk_set_private_ptr(s, pr);
- strcpy(pr->hostname, org->hostname);
- pr->port = org->port;
pr->throttled = pr->throttle_override = 0;
pr->ready = 0;
- pr->waiting = NULL;
- sk_set_private_ptr(s, pr);
-
- if (pr->c == NULL) {
- sfree(pr);
- return 1;
+ if (org->dynamic) {
+ pr->dynamic = 1;
+ pr->port = 0; /* hostname buffer is so far empty */
+ sk_set_frozen(s, 0); /* we want to receive SOCKS _now_! */
} else {
- /* asks to forward to the specified host/port for this */
- ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
+ strcpy(pr->hostname, org->hostname);
+ pr->port = org->port;
+ pr->c = new_sock_channel(org->backhandle, s);
+
+ if (pr->c == NULL) {
+ sfree(pr);
+ return 1;
+ } else {
+ /* asks to forward to the specified host/port for this */
+ ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
+ }
}
return 0;
* Open socket.
*/
pr = snew(struct PFwdPrivate);
+ pr->buffer = NULL;
pr->fn = &fn_table;
pr->c = NULL;
- strcpy(pr->hostname, desthost);
- pr->port = destport;
+ if (desthost) {
+ strcpy(pr->hostname, desthost);
+ pr->port = destport;
+ pr->dynamic = 0;
+ } else
+ pr->dynamic = 1;
pr->throttled = pr->throttle_override = 0;
pr->ready = 0;
- pr->waiting = NULL;
pr->backhandle = backhandle;
pr->s = s = new_listener(srcaddr, port, (Plug) pr,
pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
+ sfree(pr->buffer);
sfree(pr);
sk_close(s);
pr->ready = 1;
sk_set_frozen(s, 0);
sk_write(s, NULL, 0);
+ if (pr->buffer) {
+ sshfwd_write(pr->c, pr->buffer, pr->buflen);
+ sfree(pr->buffer);
+ pr->buffer = NULL;
+ }
}
projects / u / mdw / putty / blobdiff