Reintegrate tools from trunk

1 files changed, 556 insertions, 0 deletions

diff --git a/tools/plink/portfwd.c b/tools/plink/portfwd.c
new file mode 100644
index 000000000..e5874a697
--- /dev/null
+++ b/tools/plink/portfwd.c
@@ -0,0 +1,556 @@
+/*

+ * SSH port forwarding.

+ */

+

+#include <stdio.h>

+#include <stdlib.h>

+

+#include "putty.h"

+#include "ssh.h"

+

+#ifndef FALSE

+#define FALSE 0

+#endif

+#ifndef TRUE

+#define TRUE 1

+#endif

+

+struct PFwdPrivate {

+    const struct plug_function_table *fn;

+    /* the above variable absolutely *must* be the first in this structure */

+    void *c;			       /* (channel) data used by ssh.c */

+    void *backhandle;		       /* instance of SSH backend itself */

+    /* Note that backhandle need not be filled in if c is non-NULL */

+    Socket s;

+    int throttled, throttle_override;

+    int ready;

+    /*

+     * `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+8];

+    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 void pfd_log(Plug plug, int type, SockAddr addr, int port,

+		    const char *error_msg, int error_code)

+{

+    /* we have to dump these since we have no interface to logging.c */

+}

+

+static int pfd_closing(Plug plug, const char *error_msg, int error_code,

+		       int calling_back)

+{

+    struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;

+

+    /*

+     * We have no way to communicate down the forwarded connection,

+     * so if an error occurred on the socket, we just ignore it

+     * and treat it like a proper close.

+     */

+    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--) {

+	    /*

+	     * Throughout SOCKS negotiation, "hostname" is re-used as a

+	     * random protocol buffer with "port" storing the length.

+	     */ 

+	    if (pr->port >= lenof(pr->hostname)) {

+		/* Request too long. */

+		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) {

+		    /* Not CONNECT. */

+		    /* 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 user/hostname */

+		if (pr->hostname[pr->port-1] != 0)

+		    continue;	       /* haven't _finished_ user/hostname */

+		/*

+		 * 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;

+			pr->port = 8;      /* reset buffer to overwrite name */

+			continue;

+		    }

+		    pr->hostname[0] = 0;   /* reply version code */

+		    pr->hostname[1] = 90;   /* request granted */

+		    sk_write(pr->s, pr->hostname, 8);

+		    len= pr->port - 8;

+		    pr->port = GET_16BIT_MSB_FIRST(pr->hostname+2);

+		    memmove(pr->hostname, pr->hostname + 8, len);

+		    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) {

+		    /*

+		     * We're receiving a SOCKS request.

+		     */

+		    unsigned char reply[10]; /* SOCKS5 atyp=1 reply */

+		    int atype, alen = 0;

+

+		    /*

+		     * Pre-fill reply packet.

+		     * In all cases, we set BND.{HOST,ADDR} to 0.0.0.0:0

+		     * (atyp=1) in the reply; if we succeed, we don't know

+		     * the right answers, and if we fail, they should be

+		     * ignored.

+		     */

+		    memset(reply, 0, lenof(reply));

+		    reply[0] = 5; /* VER */

+		    reply[3] = 1; /* ATYP = 1 (IPv4, 0.0.0.0:0) */

+

+		    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) {

+			/* Not CONNECT or reserved field nonzero - error */

+			reply[1] = 1;	/* generic failure */

+			sk_write(pr->s, (char *) reply, lenof(reply));

+			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) {

+			/* REP=0 (success) already */

+			sk_write(pr->s, (char *) reply, lenof(reply));

+			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) {

+			/* REP=0 (success) already */

+			sk_write(pr->s, (char *) reply, lenof(reply));

+			memmove(pr->hostname, pr->hostname + 5, alen-1);

+			pr->hostname[alen-1] = '\0';

+			goto connect;

+		    } else {

+			/*

+			 * Unknown address type. (FIXME: support IPv6!)

+			 */

+			reply[1] = 8;	/* atype not supported */

+			sk_write(pr->s, (char *) reply, lenof(reply));

+			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:

+

+	/*

+	 * Freeze the socket until the SSH server confirms the

+	 * connection.

+	 */

+	sk_set_frozen(pr->s, 1);

+

+	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;

+

+	/*

+	 * 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;

+	    sk_set_frozen(pr->s, 1);

+	}

+    }

+    return 1;

+}

+

+static void pfd_sent(Plug plug, int bufsize)

+{

+    struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;

+

+    if (pr->c)

+	sshfwd_unthrottle(pr->c, bufsize);

+}

+

+/*

+ * Called when receiving a PORT OPEN from the server

+ */

+const char *pfd_newconnect(Socket *s, char *hostname, int port,

+			   void *c, const Config *cfg, int addressfamily)

+{

+    static const struct plug_function_table fn_table = {

+	pfd_log,

+	pfd_closing,

+	pfd_receive,

+	pfd_sent,

+	NULL

+    };

+

+    SockAddr addr;

+    const char *err;

+    char *dummy_realhost;

+    struct PFwdPrivate *pr;

+

+    /*

+     * Try to find host.

+     */

+    addr = name_lookup(hostname, port, &dummy_realhost, cfg, addressfamily);

+    if ((err = sk_addr_error(addr)) != NULL) {

+	sk_addr_free(addr);

+	return err;

+    }

+

+    /*

+     * Open socket.

+     */

+    pr = snew(struct PFwdPrivate);

+    pr->buffer = NULL;

+    pr->fn = &fn_table;

+    pr->throttled = pr->throttle_override = 0;

+    pr->ready = 1;

+    pr->c = c;

+    pr->backhandle = NULL;	       /* we shouldn't need this */

+    pr->dynamic = 0;

+

+    pr->s = *s = new_connection(addr, dummy_realhost, port,

+				0, 1, 0, 0, (Plug) pr, cfg);

+    if ((err = sk_socket_error(*s)) != NULL) {

+	sfree(pr);

+	return err;

+    }

+

+    sk_set_private_ptr(*s, pr);

+    return NULL;

+}

+

+/*

+ called when someone connects to the local port

+ */

+

+static int pfd_accepting(Plug p, OSSocket sock)

+{

+    static const struct plug_function_table fn_table = {

+	pfd_log,

+	pfd_closing,

+	pfd_receive,

+	pfd_sent,

+	NULL

+    };

+    struct PFwdPrivate *pr, *org;

+    Socket s;

+    const char *err;

+

+    org = (struct PFwdPrivate *)p;

+    pr = snew(struct PFwdPrivate);

+    pr->buffer = NULL;

+    pr->fn = &fn_table;

+

+    pr->c = NULL;

+    pr->backhandle = org->backhandle;

+

+    pr->s = s = sk_register(sock, (Plug) pr);

+    if ((err = sk_socket_error(s)) != NULL) {

+	sfree(pr);

+	return err != NULL;

+    }

+

+    sk_set_private_ptr(s, pr);

+

+    pr->throttled = pr->throttle_override = 0;

+    pr->ready = 0;

+

+    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 {

+	pr->dynamic = 0;

+	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;

+}

+

+

+/* Add a new forwarding from port -> desthost:destport

+ sets up a listener on the local machine on (srcaddr:)port

+ */

+const char *pfd_addforward(char *desthost, int destport, char *srcaddr,

+			   int port, void *backhandle, const Config *cfg,

+			   void **sockdata, int address_family)

+{

+    static const struct plug_function_table fn_table = {

+	pfd_log,

+	pfd_closing,

+	pfd_receive,		       /* should not happen... */

+	pfd_sent,		       /* also should not happen */

+	pfd_accepting

+    };

+

+    const char *err;

+    struct PFwdPrivate *pr;

+    Socket s;

+

+    /*

+     * Open socket.

+     */

+    pr = snew(struct PFwdPrivate);

+    pr->buffer = NULL;

+    pr->fn = &fn_table;

+    pr->c = NULL;

+    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->backhandle = backhandle;

+

+    pr->s = s = new_listener(srcaddr, port, (Plug) pr,

+			     !cfg->lport_acceptall, cfg, address_family);

+    if ((err = sk_socket_error(s)) != NULL) {

+	sfree(pr);

+	return err;

+    }

+

+    sk_set_private_ptr(s, pr);

+

+    *sockdata = (void *)s;

+

+    return NULL;

+}

+

+void pfd_close(Socket s)

+{

+    struct PFwdPrivate *pr;

+

+    if (!s)

+	return;

+

+    pr = (struct PFwdPrivate *) sk_get_private_ptr(s);

+

+    sfree(pr->buffer);

+    sfree(pr);

+

+    sk_close(s);

+}

+

+/*

+ * Terminate a listener.

+ */

+void pfd_terminate(void *sv)

+{

+    pfd_close((Socket)sv);

+}

+

+void pfd_unthrottle(Socket s)

+{

+    struct PFwdPrivate *pr;

+    if (!s)

+	return;

+    pr = (struct PFwdPrivate *) sk_get_private_ptr(s);

+

+    pr->throttled = 0;

+    sk_set_frozen(s, pr->throttled || pr->throttle_override);

+}

+

+void pfd_override_throttle(Socket s, int enable)

+{

+    struct PFwdPrivate *pr;

+    if (!s)

+	return;

+    pr = (struct PFwdPrivate *) sk_get_private_ptr(s);

+

+    pr->throttle_override = enable;

+    sk_set_frozen(s, pr->throttled || pr->throttle_override);

+}

+

+/*

+ * Called to send data down the raw connection.

+ */

+int pfd_send(Socket s, char *data, int len)

+{

+    if (s == NULL)

+	return 0;

+    return sk_write(s, data, len);

+}

+

+

+void pfd_confirm(Socket s)

+{

+    struct PFwdPrivate *pr;

+

+    if (s == NULL)

+	return;

+

+    pr = (struct PFwdPrivate *) sk_get_private_ptr(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;

+    }

+}