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authormarha <marha@users.sourceforge.net>2014-04-14 23:49:11 +0200
committermarha <marha@users.sourceforge.net>2014-04-14 23:49:11 +0200
commit3053928d3e9e12e59c46917113bad496487f1d28 (patch)
tree591c17cafc365399cc88774bba985af7276d957e /tools/plink/portfwd.c
parent7c21629fbeb51b65fd0625bb36d888587d62fd89 (diff)
parenta3fe3e22d85e8aa795df85c21814fc84cac42e99 (diff)
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Merge remote-tracking branch 'origin/released'
Conflicts: tools/plink/misc.h tools/plink/ssh.c tools/plink/sshbn.c tools/plink/winplink.c
Diffstat (limited to 'tools/plink/portfwd.c')
-rw-r--r--tools/plink/portfwd.c1203
1 files changed, 636 insertions, 567 deletions
diff --git a/tools/plink/portfwd.c b/tools/plink/portfwd.c
index 545dfecd4..e3e63e39a 100644
--- a/tools/plink/portfwd.c
+++ b/tools/plink/portfwd.c
@@ -1,567 +1,636 @@
-/*
- * 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;
-
- if (error_msg) {
- /*
- * Socket error. Slam the connection instantly shut.
- */
- sshfwd_unclean_close(pr->c);
- } else {
- /*
- * Ordinary EOF received on socket. Send an EOF on the SSH
- * channel.
- */
- if (pr->c)
- sshfwd_write_eof(pr->c);
- }
-
- 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, Conf *conf, 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, conf, 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, conf);
- 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, Conf *conf,
- 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,
- !conf_get_int(conf, CONF_lport_acceptall),
- conf, 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_send_eof(Socket s)
-{
- sk_write_eof(s);
-}
-
-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;
- }
-}
+/*
+ * 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 PortForwarding {
+ const struct plug_function_table *fn;
+ /* the above variable absolutely *must* be the first in this structure */
+ struct ssh_channel *c; /* channel structure held 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 the nonzero values are also a state machine
+ * tracking where the SOCKS exchange has got to.
+ */
+ int dynamic;
+ /*
+ * `hostname' and `port' are the real hostname and port, once
+ * we know what we're connecting to.
+ */
+ char *hostname;
+ int port;
+ /*
+ * `socksbuf' is the buffer we use to accumulate a SOCKS request.
+ */
+ char *socksbuf;
+ int sockslen, sockssize;
+ /*
+ * 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;
+};
+
+struct PortListener {
+ const struct plug_function_table *fn;
+ /* the above variable absolutely *must* be the first in this structure */
+ void *backhandle; /* instance of SSH backend itself */
+ Socket s;
+ /*
+ * `dynamic' is set to 0 for an ordinary forwarded port, and
+ * nonzero for SOCKS-style dynamic port forwarding.
+ */
+ int dynamic;
+ /*
+ * `hostname' and `port' are the real hostname and port, for
+ * ordinary forwardings.
+ */
+ char *hostname;
+ int port;
+};
+
+static struct PortForwarding *new_portfwd_state(void)
+{
+ struct PortForwarding *pf = snew(struct PortForwarding);
+ pf->hostname = NULL;
+ pf->socksbuf = NULL;
+ pf->sockslen = pf->sockssize = 0;
+ pf->buffer = NULL;
+ return pf;
+}
+
+static void free_portfwd_state(struct PortForwarding *pf)
+{
+ if (!pf)
+ return;
+ sfree(pf->hostname);
+ sfree(pf->socksbuf);
+ sfree(pf->buffer);
+ sfree(pf);
+}
+
+static struct PortListener *new_portlistener_state(void)
+{
+ struct PortListener *pl = snew(struct PortListener);
+ pl->hostname = NULL;
+ return pl;
+}
+
+static void free_portlistener_state(struct PortListener *pl)
+{
+ if (!pl)
+ return;
+ sfree(pl->hostname);
+ sfree(pl);
+}
+
+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 void pfl_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 PortForwarding *pf = (struct PortForwarding *) plug;
+
+ if (error_msg) {
+ /*
+ * Socket error. Slam the connection instantly shut.
+ */
+ if (pf->c) {
+ sshfwd_unclean_close(pf->c, error_msg);
+ } else {
+ /*
+ * We might not have an SSH channel, if a socket error
+ * occurred during SOCKS negotiation. If not, we must
+ * clean ourself up without sshfwd_unclean_close's call
+ * back to pfd_close.
+ */
+ pfd_close(pf);
+ }
+ } else {
+ /*
+ * Ordinary EOF received on socket. Send an EOF on the SSH
+ * channel.
+ */
+ if (pf->c)
+ sshfwd_write_eof(pf->c);
+ }
+
+ return 1;
+}
+
+static int pfl_closing(Plug plug, const char *error_msg, int error_code,
+ int calling_back)
+{
+ struct PortListener *pl = (struct PortListener *) plug;
+ pfl_terminate(pl);
+ return 1;
+}
+
+static int pfd_receive(Plug plug, int urgent, char *data, int len)
+{
+ struct PortForwarding *pf = (struct PortForwarding *) plug;
+ if (pf->dynamic) {
+ while (len--) {
+ if (pf->sockslen >= pf->sockssize) {
+ pf->sockssize = pf->sockslen * 5 / 4 + 256;
+ pf->socksbuf = sresize(pf->socksbuf, pf->sockssize, char);
+ }
+ pf->socksbuf[pf->sockslen++] = *data++;
+
+ /*
+ * Now check what's in the buffer to see if it's a
+ * valid and complete message in the SOCKS exchange.
+ */
+ if ((pf->dynamic == 1 || (pf->dynamic >> 12) == 4) &&
+ pf->socksbuf[0] == 4) {
+ /*
+ * SOCKS 4.
+ */
+ if (pf->dynamic == 1)
+ pf->dynamic = 0x4000;
+ if (pf->sockslen < 2)
+ continue; /* don't have command code yet */
+ if (pf->socksbuf[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(pf->s, data, 8);
+ pfd_close(pf);
+ return 1;
+ }
+ if (pf->sockslen <= 8)
+ continue; /* haven't started user/hostname */
+ if (pf->socksbuf[pf->sockslen-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 (pf->socksbuf[4] == 0 && pf->socksbuf[5] == 0 &&
+ pf->socksbuf[6] == 0 && pf->socksbuf[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 (pf->dynamic == 0x4000) {
+ pf->dynamic = 0x4001;
+ pf->sockslen = 8; /* reset buffer to overwrite name */
+ continue;
+ }
+ pf->socksbuf[0] = 0; /* reply version code */
+ pf->socksbuf[1] = 90; /* request granted */
+ sk_write(pf->s, pf->socksbuf, 8);
+ len = pf->sockslen - 8;
+ pf->port = GET_16BIT_MSB_FIRST(pf->socksbuf+2);
+ pf->hostname = snewn(len+1, char);
+ pf->hostname[len] = '\0';
+ memcpy(pf->hostname, pf->socksbuf + 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.
+ */
+ pf->socksbuf[0] = 0; /* reply version code */
+ pf->socksbuf[1] = 90; /* request granted */
+ sk_write(pf->s, pf->socksbuf, 8);
+ pf->port = GET_16BIT_MSB_FIRST(pf->socksbuf+2);
+ pf->hostname = dupprintf("%d.%d.%d.%d",
+ (unsigned char)pf->socksbuf[4],
+ (unsigned char)pf->socksbuf[5],
+ (unsigned char)pf->socksbuf[6],
+ (unsigned char)pf->socksbuf[7]);
+ goto connect;
+ }
+ }
+
+ if ((pf->dynamic == 1 || (pf->dynamic >> 12) == 5) &&
+ pf->socksbuf[0] == 5) {
+ /*
+ * SOCKS 5.
+ */
+ if (pf->dynamic == 1)
+ pf->dynamic = 0x5000;
+
+ if (pf->dynamic == 0x5000) {
+ int i, method;
+ char data[2];
+ /*
+ * We're receiving a set of method identifiers.
+ */
+ if (pf->sockslen < 2)
+ continue; /* no method count yet */
+ if (pf->sockslen < 2 + (unsigned char)pf->socksbuf[1])
+ continue; /* no methods yet */
+ method = 0xFF; /* invalid */
+ for (i = 0; i < (unsigned char)pf->socksbuf[1]; i++)
+ if (pf->socksbuf[2+i] == 0) {
+ method = 0;/* no auth */
+ break;
+ }
+ data[0] = 5;
+ data[1] = method;
+ sk_write(pf->s, data, 2);
+ pf->dynamic = 0x5001;
+ pf->sockslen = 0; /* re-empty the buffer */
+ continue;
+ }
+
+ if (pf->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 (pf->sockslen < 6) continue;
+ atype = (unsigned char)pf->socksbuf[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)pf->socksbuf[4];
+ if (pf->sockslen < 6 + alen) continue;
+ if (pf->socksbuf[1] != 1 || pf->socksbuf[2] != 0) {
+ /* Not CONNECT or reserved field nonzero - error */
+ reply[1] = 1; /* generic failure */
+ sk_write(pf->s, (char *) reply, lenof(reply));
+ pfd_close(pf);
+ return 1;
+ }
+ /*
+ * Now we have a viable connect request. Switch
+ * on atype.
+ */
+ pf->port = GET_16BIT_MSB_FIRST(pf->socksbuf+4+alen);
+ if (atype == 1) {
+ /* REP=0 (success) already */
+ sk_write(pf->s, (char *) reply, lenof(reply));
+ pf->hostname = dupprintf("%d.%d.%d.%d",
+ (unsigned char)pf->socksbuf[4],
+ (unsigned char)pf->socksbuf[5],
+ (unsigned char)pf->socksbuf[6],
+ (unsigned char)pf->socksbuf[7]);
+ goto connect;
+ } else if (atype == 3) {
+ /* REP=0 (success) already */
+ sk_write(pf->s, (char *) reply, lenof(reply));
+ pf->hostname = snewn(alen, char);
+ pf->hostname[alen-1] = '\0';
+ memcpy(pf->hostname, pf->socksbuf + 5, alen-1);
+ goto connect;
+ } else {
+ /*
+ * Unknown address type. (FIXME: support IPv6!)
+ */
+ reply[1] = 8; /* atype not supported */
+ sk_write(pf->s, (char *) reply, lenof(reply));
+ pfd_close(pf);
+ 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(pf);
+ return 1;
+ }
+ return 1;
+
+ /*
+ * We come here when we're ready to make an actual
+ * connection.
+ */
+ connect:
+ sfree(pf->socksbuf);
+ pf->socksbuf = NULL;
+
+ /*
+ * Freeze the socket until the SSH server confirms the
+ * connection.
+ */
+ sk_set_frozen(pf->s, 1);
+
+ pf->c = new_sock_channel(pf->backhandle, pf);
+ if (pf->c == NULL) {
+ pfd_close(pf);
+ return 1;
+ } else {
+ /* asks to forward to the specified host/port for this */
+ ssh_send_port_open(pf->c, pf->hostname, pf->port, "forwarding");
+ }
+ pf->dynamic = 0;
+
+ /*
+ * If there's any data remaining in our current buffer,
+ * save it to be sent on pfd_confirm().
+ */
+ if (len > 0) {
+ pf->buffer = snewn(len, char);
+ memcpy(pf->buffer, data, len);
+ pf->buflen = len;
+ }
+ }
+ if (pf->ready) {
+ if (sshfwd_write(pf->c, data, len) > 0) {
+ pf->throttled = 1;
+ sk_set_frozen(pf->s, 1);
+ }
+ }
+ return 1;
+}
+
+static void pfd_sent(Plug plug, int bufsize)
+{
+ struct PortForwarding *pf = (struct PortForwarding *) plug;
+
+ if (pf->c)
+ sshfwd_unthrottle(pf->c, bufsize);
+}
+
+/*
+ * Called when receiving a PORT OPEN from the server to make a
+ * connection to a destination host.
+ *
+ * On success, returns NULL and fills in *pf_ret. On error, returns a
+ * dynamically allocated error message string.
+ */
+char *pfd_connect(struct PortForwarding **pf_ret, char *hostname,int port,
+ void *c, Conf *conf, 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 PortForwarding *pf;
+
+ /*
+ * Try to find host.
+ */
+ addr = name_lookup(hostname, port, &dummy_realhost, conf, addressfamily);
+ if ((err = sk_addr_error(addr)) != NULL) {
+ char *err_ret = dupstr(err);
+ sk_addr_free(addr);
+ sfree(dummy_realhost);
+ return err_ret;
+ }
+
+ /*
+ * Open socket.
+ */
+ pf = *pf_ret = new_portfwd_state();
+ pf->fn = &fn_table;
+ pf->throttled = pf->throttle_override = 0;
+ pf->ready = 1;
+ pf->c = c;
+ pf->backhandle = NULL; /* we shouldn't need this */
+ pf->dynamic = 0;
+
+ pf->s = new_connection(addr, dummy_realhost, port,
+ 0, 1, 0, 0, (Plug) pf, conf);
+ sfree(dummy_realhost);
+ if ((err = sk_socket_error(pf->s)) != NULL) {
+ char *err_ret = dupstr(err);
+ sk_close(pf->s);
+ free_portfwd_state(pf);
+ *pf_ret = NULL;
+ return err_ret;
+ }
+
+ return NULL;
+}
+
+/*
+ called when someone connects to the local port
+ */
+
+static int pfl_accepting(Plug p, accept_fn_t constructor, accept_ctx_t ctx)
+{
+ static const struct plug_function_table fn_table = {
+ pfd_log,
+ pfd_closing,
+ pfd_receive,
+ pfd_sent,
+ NULL
+ };
+ struct PortForwarding *pf;
+ struct PortListener *pl;
+ Socket s;
+ const char *err;
+
+ pl = (struct PortListener *)p;
+ pf = new_portfwd_state();
+ pf->fn = &fn_table;
+
+ pf->c = NULL;
+ pf->backhandle = pl->backhandle;
+
+ pf->s = s = constructor(ctx, (Plug) pf);
+ if ((err = sk_socket_error(s)) != NULL) {
+ free_portfwd_state(pf);
+ return err != NULL;
+ }
+
+ pf->throttled = pf->throttle_override = 0;
+ pf->ready = 0;
+
+ if (pl->dynamic) {
+ pf->dynamic = 1;
+ pf->port = 0; /* "hostname" buffer is so far empty */
+ sk_set_frozen(s, 0); /* we want to receive SOCKS _now_! */
+ } else {
+ pf->dynamic = 0;
+ pf->hostname = dupstr(pl->hostname);
+ pf->port = pl->port;
+ pf->c = new_sock_channel(pl->backhandle, pf);
+
+ if (pf->c == NULL) {
+ free_portfwd_state(pf);
+ return 1;
+ } else {
+ /* asks to forward to the specified host/port for this */
+ ssh_send_port_open(pf->c, pf->hostname, pf->port, "forwarding");
+ }
+ }
+
+ return 0;
+}
+
+
+/*
+ * Add a new port-forwarding listener from srcaddr:port -> desthost:destport.
+ *
+ * On success, returns NULL and fills in *pl_ret. On error, returns a
+ * dynamically allocated error message string.
+ */
+char *pfl_listen(char *desthost, int destport, char *srcaddr,
+ int port, void *backhandle, Conf *conf,
+ struct PortListener **pl_ret, int address_family)
+{
+ static const struct plug_function_table fn_table = {
+ pfl_log,
+ pfl_closing,
+ NULL, /* recv */
+ NULL, /* send */
+ pfl_accepting
+ };
+
+ const char *err;
+ struct PortListener *pl;
+
+ /*
+ * Open socket.
+ */
+ pl = *pl_ret = new_portlistener_state();
+ pl->fn = &fn_table;
+ if (desthost) {
+ pl->hostname = dupstr(desthost);
+ pl->port = destport;
+ pl->dynamic = 0;
+ } else
+ pl->dynamic = 1;
+ pl->backhandle = backhandle;
+
+ pl->s = new_listener(srcaddr, port, (Plug) pl,
+ !conf_get_int(conf, CONF_lport_acceptall),
+ conf, address_family);
+ if ((err = sk_socket_error(pl->s)) != NULL) {
+ char *err_ret = dupstr(err);
+ sk_close(pl->s);
+ free_portlistener_state(pl);
+ *pl_ret = NULL;
+ return err_ret;
+ }
+
+ return NULL;
+}
+
+void pfd_close(struct PortForwarding *pf)
+{
+ if (!pf)
+ return;
+
+ sk_close(pf->s);
+ free_portfwd_state(pf);
+}
+
+/*
+ * Terminate a listener.
+ */
+void pfl_terminate(struct PortListener *pl)
+{
+ if (!pl)
+ return;
+
+ sk_close(pl->s);
+ free_portlistener_state(pl);
+}
+
+void pfd_unthrottle(struct PortForwarding *pf)
+{
+ if (!pf)
+ return;
+
+ pf->throttled = 0;
+ sk_set_frozen(pf->s, pf->throttled || pf->throttle_override);
+}
+
+void pfd_override_throttle(struct PortForwarding *pf, int enable)
+{
+ if (!pf)
+ return;
+
+ pf->throttle_override = enable;
+ sk_set_frozen(pf->s, pf->throttled || pf->throttle_override);
+}
+
+/*
+ * Called to send data down the raw connection.
+ */
+int pfd_send(struct PortForwarding *pf, char *data, int len)
+{
+ if (pf == NULL)
+ return 0;
+ return sk_write(pf->s, data, len);
+}
+
+void pfd_send_eof(struct PortForwarding *pf)
+{
+ sk_write_eof(pf->s);
+}
+
+void pfd_confirm(struct PortForwarding *pf)
+{
+ if (pf == NULL)
+ return;
+
+ pf->ready = 1;
+ sk_set_frozen(pf->s, 0);
+ sk_write(pf->s, NULL, 0);
+ if (pf->buffer) {
+ sshfwd_write(pf->c, pf->buffer, pf->buflen);
+ sfree(pf->buffer);
+ pf->buffer = NULL;
+ }
+}