mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-01-08 08:58:00 +00:00
b4e1bca2c3
This is a sweeping change applied across the whole code base by a spot of Emacs Lisp. Now, everywhere I declare a vtable filled with function pointers (and the occasional const data member), all the members of the vtable structure are initialised by name using the '.fieldname = value' syntax introduced in C99. We were already using this syntax for a handful of things in the new key-generation progress report system, so it's not new to the code base as a whole. The advantage is that now, when a vtable only declares a subset of the available fields, I can initialise the rest to NULL or zero just by leaving them out. This is most dramatic in a couple of the outlying vtables in things like psocks (which has a ConnectionLayerVtable containing only one non-NULL method), but less dramatically, it means that the new 'flags' field in BackendVtable can be completely left out of every backend definition except for the SUPDUP one which defines it to a nonzero value. Similarly, the test_for_upstream method only used by SSH doesn't have to be mentioned in the rest of the backends; network Plugs for listening sockets don't have to explicitly null out 'receive' and 'sent', and vice versa for 'accepting', and so on. While I'm at it, I've normalised the declarations so they don't use the unnecessarily verbose 'struct' keyword. Also a handful of them weren't const; now they are.
1175 lines
36 KiB
C
1175 lines
36 KiB
C
/*
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* SSH port forwarding.
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*/
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "putty.h"
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#include "ssh.h"
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#include "sshchan.h"
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/*
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* Enumeration of values that live in the 'socks_state' field of
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* struct PortForwarding.
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*/
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typedef enum {
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SOCKS_NONE, /* direct connection (no SOCKS, or SOCKS already done) */
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SOCKS_INITIAL, /* don't know if we're SOCKS 4 or 5 yet */
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SOCKS_4, /* expect a SOCKS 4 (or 4A) connection message */
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SOCKS_5_INITIAL, /* expect a SOCKS 5 preliminary message */
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SOCKS_5_CONNECT /* expect a SOCKS 5 connection message */
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} SocksState;
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typedef struct PortForwarding {
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SshChannel *c; /* channel structure held by SSH connection layer */
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ConnectionLayer *cl; /* the connection layer itself */
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/* Note that ssh need not be filled in if c is non-NULL */
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Socket *s;
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bool input_wanted;
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bool ready;
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SocksState socks_state;
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/*
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* `hostname' and `port' are the real hostname and port, once
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* we know what we're connecting to.
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*/
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char *hostname;
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int port;
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/*
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* `socksbuf' is the buffer we use to accumulate the initial SOCKS
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* segment of the incoming data, plus anything after that that we
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* receive before we're ready to send data to the SSH server.
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*/
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strbuf *socksbuf;
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size_t socksbuf_consumed;
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Plug plug;
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Channel chan;
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} PortForwarding;
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struct PortListener {
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ConnectionLayer *cl;
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Socket *s;
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bool is_dynamic;
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/*
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* `hostname' and `port' are the real hostname and port, for
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* ordinary forwardings.
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*/
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char *hostname;
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int port;
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Plug plug;
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};
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static struct PortForwarding *new_portfwd_state(void)
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{
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struct PortForwarding *pf = snew(struct PortForwarding);
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pf->hostname = NULL;
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pf->socksbuf = NULL;
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return pf;
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}
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static void free_portfwd_state(struct PortForwarding *pf)
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{
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if (!pf)
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return;
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sfree(pf->hostname);
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if (pf->socksbuf)
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strbuf_free(pf->socksbuf);
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sfree(pf);
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}
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static struct PortListener *new_portlistener_state(void)
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{
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struct PortListener *pl = snew(struct PortListener);
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pl->hostname = NULL;
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return pl;
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}
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static void free_portlistener_state(struct PortListener *pl)
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{
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if (!pl)
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return;
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sfree(pl->hostname);
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sfree(pl);
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}
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static void pfd_log(Plug *plug, PlugLogType type, SockAddr *addr, int port,
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const char *error_msg, int error_code)
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{
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/* we have to dump these since we have no interface to logging.c */
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}
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static void pfl_log(Plug *plug, PlugLogType type, SockAddr *addr, int port,
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const char *error_msg, int error_code)
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{
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/* we have to dump these since we have no interface to logging.c */
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}
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static void pfd_close(struct PortForwarding *pf);
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static void pfd_closing(Plug *plug, const char *error_msg, int error_code,
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bool calling_back)
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{
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struct PortForwarding *pf =
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container_of(plug, struct PortForwarding, plug);
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if (error_msg) {
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/*
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* Socket error. Slam the connection instantly shut.
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*/
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if (pf->c) {
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sshfwd_initiate_close(pf->c, error_msg);
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} else {
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/*
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* We might not have an SSH channel, if a socket error
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* occurred during SOCKS negotiation. If not, we must
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* clean ourself up without sshfwd_initiate_close's call
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* back to pfd_close.
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*/
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pfd_close(pf);
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}
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} else {
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/*
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* Ordinary EOF received on socket. Send an EOF on the SSH
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* channel.
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*/
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if (pf->c)
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sshfwd_write_eof(pf->c);
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}
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}
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static void pfl_terminate(struct PortListener *pl);
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static void pfl_closing(Plug *plug, const char *error_msg, int error_code,
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bool calling_back)
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{
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struct PortListener *pl = (struct PortListener *) plug;
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pfl_terminate(pl);
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}
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static SshChannel *wrap_lportfwd_open(
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ConnectionLayer *cl, const char *hostname, int port,
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Socket *s, Channel *chan)
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{
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SocketPeerInfo *pi;
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char *description;
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SshChannel *toret;
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pi = sk_peer_info(s);
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if (pi && pi->log_text) {
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description = dupprintf("forwarding from %s", pi->log_text);
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} else {
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description = dupstr("forwarding");
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}
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toret = ssh_lportfwd_open(cl, hostname, port, description, pi, chan);
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sk_free_peer_info(pi);
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sfree(description);
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return toret;
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}
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static char *ipv4_to_string(unsigned ipv4)
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{
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return dupprintf("%u.%u.%u.%u",
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(ipv4 >> 24) & 0xFF, (ipv4 >> 16) & 0xFF,
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(ipv4 >> 8) & 0xFF, (ipv4 ) & 0xFF);
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}
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static char *ipv6_to_string(ptrlen ipv6)
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{
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const unsigned char *addr = ipv6.ptr;
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assert(ipv6.len == 16);
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return dupprintf("%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
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(unsigned)GET_16BIT_MSB_FIRST(addr + 0),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 2),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 4),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 6),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 8),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 10),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 12),
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(unsigned)GET_16BIT_MSB_FIRST(addr + 14));
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}
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static void pfd_receive(Plug *plug, int urgent, const char *data, size_t len)
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{
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struct PortForwarding *pf =
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container_of(plug, struct PortForwarding, plug);
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if (len == 0)
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return;
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if (pf->socks_state != SOCKS_NONE) {
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BinarySource src[1];
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/*
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* Store all the data we've got in socksbuf.
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*/
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put_data(pf->socksbuf, data, len);
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/*
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* Check the start of socksbuf to see if it's a valid and
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* complete message in the SOCKS exchange.
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*/
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if (pf->socks_state == SOCKS_INITIAL) {
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/* Preliminary: check the first byte of the data (which we
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* _must_ have by now) to find out which SOCKS major
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* version we're speaking. */
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switch (pf->socksbuf->u[0]) {
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case 4:
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pf->socks_state = SOCKS_4;
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break;
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case 5:
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pf->socks_state = SOCKS_5_INITIAL;
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break;
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default:
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pfd_close(pf); /* unrecognised version */
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return;
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}
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}
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BinarySource_BARE_INIT(src, pf->socksbuf->u, pf->socksbuf->len);
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get_data(src, pf->socksbuf_consumed);
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while (pf->socks_state != SOCKS_NONE) {
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unsigned socks_version, message_type, reserved_byte;
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unsigned reply_code, port, ipv4, method;
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ptrlen methods;
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const char *socks4_hostname;
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strbuf *output;
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switch (pf->socks_state) {
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case SOCKS_INITIAL:
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case SOCKS_NONE:
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unreachable("These case values cannot appear");
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case SOCKS_4:
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/* SOCKS 4/4A connect message */
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socks_version = get_byte(src);
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message_type = get_byte(src);
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if (get_err(src) == BSE_OUT_OF_DATA)
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return;
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if (socks_version == 4 && message_type == 1) {
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/* CONNECT message */
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bool name_based = false;
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port = get_uint16(src);
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ipv4 = get_uint32(src);
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if (ipv4 > 0x00000000 && ipv4 < 0x00000100) {
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/*
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* Addresses in this range indicate the SOCKS 4A
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* extension to specify a hostname, which comes
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* after the username.
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*/
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name_based = true;
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}
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get_asciz(src); /* skip username */
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socks4_hostname = name_based ? get_asciz(src) : NULL;
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if (get_err(src) == BSE_OUT_OF_DATA)
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return;
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if (get_err(src))
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goto socks4_reject;
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pf->port = port;
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if (name_based) {
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pf->hostname = dupstr(socks4_hostname);
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} else {
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pf->hostname = ipv4_to_string(ipv4);
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}
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output = strbuf_new();
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put_byte(output, 0); /* reply version */
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put_byte(output, 90); /* SOCKS 4 'request granted' */
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put_uint16(output, 0); /* null port field */
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put_uint32(output, 0); /* null address field */
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sk_write(pf->s, output->u, output->len);
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strbuf_free(output);
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pf->socks_state = SOCKS_NONE;
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pf->socksbuf_consumed = src->pos;
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break;
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}
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socks4_reject:
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output = strbuf_new();
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put_byte(output, 0); /* reply version */
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put_byte(output, 91); /* SOCKS 4 'request rejected' */
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put_uint16(output, 0); /* null port field */
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put_uint32(output, 0); /* null address field */
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sk_write(pf->s, output->u, output->len);
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strbuf_free(output);
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pfd_close(pf);
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return;
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case SOCKS_5_INITIAL:
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/* SOCKS 5 initial method list */
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socks_version = get_byte(src);
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methods = get_pstring(src);
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method = 0xFF; /* means 'no usable method found' */
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{
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int i;
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for (i = 0; i < methods.len; i++) {
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if (((const unsigned char *)methods.ptr)[i] == 0 ) {
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method = 0; /* no auth */
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break;
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}
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}
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}
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if (get_err(src) == BSE_OUT_OF_DATA)
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return;
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if (get_err(src))
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method = 0xFF;
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output = strbuf_new();
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put_byte(output, 5); /* SOCKS version */
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put_byte(output, method); /* selected auth method */
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sk_write(pf->s, output->u, output->len);
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strbuf_free(output);
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if (method == 0xFF) {
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pfd_close(pf);
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return;
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}
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pf->socks_state = SOCKS_5_CONNECT;
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pf->socksbuf_consumed = src->pos;
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break;
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case SOCKS_5_CONNECT:
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/* SOCKS 5 connect message */
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socks_version = get_byte(src);
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message_type = get_byte(src);
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reserved_byte = get_byte(src);
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if (socks_version == 5 && message_type == 1 &&
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reserved_byte == 0) {
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reply_code = 0; /* success */
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switch (get_byte(src)) {
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case 1: /* IPv4 */
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pf->hostname = ipv4_to_string(get_uint32(src));
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break;
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case 4: /* IPv6 */
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pf->hostname = ipv6_to_string(get_data(src, 16));
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break;
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case 3: /* unresolved domain name */
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pf->hostname = mkstr(get_pstring(src));
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break;
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default:
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pf->hostname = NULL;
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reply_code = 8; /* address type not supported */
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break;
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}
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pf->port = get_uint16(src);
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} else {
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reply_code = 7; /* command not supported */
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}
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if (get_err(src) == BSE_OUT_OF_DATA)
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return;
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if (get_err(src))
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reply_code = 1; /* general server failure */
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output = strbuf_new();
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put_byte(output, 5); /* SOCKS version */
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put_byte(output, reply_code);
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put_byte(output, 0); /* reserved */
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put_byte(output, 1); /* IPv4 address follows */
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put_uint32(output, 0); /* bound IPv4 address (unused) */
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put_uint16(output, 0); /* bound port number (unused) */
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sk_write(pf->s, output->u, output->len);
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strbuf_free(output);
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if (reply_code != 0) {
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pfd_close(pf);
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return;
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}
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pf->socks_state = SOCKS_NONE;
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pf->socksbuf_consumed = src->pos;
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break;
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}
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}
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/*
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* We come here when we're ready to make an actual
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* connection.
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*/
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/*
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* Freeze the socket until the SSH server confirms the
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* connection.
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*/
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sk_set_frozen(pf->s, true);
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pf->c = wrap_lportfwd_open(pf->cl, pf->hostname, pf->port, pf->s,
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&pf->chan);
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}
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if (pf->ready)
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sshfwd_write(pf->c, data, len);
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}
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static void pfd_sent(Plug *plug, size_t bufsize)
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{
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struct PortForwarding *pf =
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container_of(plug, struct PortForwarding, plug);
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if (pf->c)
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sshfwd_unthrottle(pf->c, bufsize);
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}
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static const PlugVtable PortForwarding_plugvt = {
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.log = pfd_log,
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.closing = pfd_closing,
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.receive = pfd_receive,
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.sent = pfd_sent,
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};
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static void pfd_chan_free(Channel *chan);
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static void pfd_open_confirmation(Channel *chan);
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static void pfd_open_failure(Channel *chan, const char *errtext);
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static size_t pfd_send(
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Channel *chan, bool is_stderr, const void *data, size_t len);
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static void pfd_send_eof(Channel *chan);
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static void pfd_set_input_wanted(Channel *chan, bool wanted);
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static char *pfd_log_close_msg(Channel *chan);
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static const ChannelVtable PortForwarding_channelvt = {
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.free = pfd_chan_free,
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.open_confirmation = pfd_open_confirmation,
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.open_failed = pfd_open_failure,
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.send = pfd_send,
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.send_eof = pfd_send_eof,
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.set_input_wanted = pfd_set_input_wanted,
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.log_close_msg = pfd_log_close_msg,
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.want_close = chan_default_want_close,
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.rcvd_exit_status = chan_no_exit_status,
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.rcvd_exit_signal = chan_no_exit_signal,
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.rcvd_exit_signal_numeric = chan_no_exit_signal_numeric,
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.run_shell = chan_no_run_shell,
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.run_command = chan_no_run_command,
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.run_subsystem = chan_no_run_subsystem,
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.enable_x11_forwarding = chan_no_enable_x11_forwarding,
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.enable_agent_forwarding = chan_no_enable_agent_forwarding,
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.allocate_pty = chan_no_allocate_pty,
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.set_env = chan_no_set_env,
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.send_break = chan_no_send_break,
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.send_signal = chan_no_send_signal,
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.change_window_size = chan_no_change_window_size,
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.request_response = chan_no_request_response,
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};
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Channel *portfwd_raw_new(ConnectionLayer *cl, Plug **plug, bool start_ready)
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{
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struct PortForwarding *pf;
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pf = new_portfwd_state();
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pf->plug.vt = &PortForwarding_plugvt;
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pf->chan.initial_fixed_window_size = 0;
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pf->chan.vt = &PortForwarding_channelvt;
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pf->input_wanted = true;
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pf->c = NULL;
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pf->cl = cl;
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pf->input_wanted = true;
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pf->ready = start_ready;
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pf->socks_state = SOCKS_NONE;
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pf->hostname = NULL;
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pf->port = 0;
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*plug = &pf->plug;
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return &pf->chan;
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}
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|
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void portfwd_raw_free(Channel *pfchan)
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{
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struct PortForwarding *pf;
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assert(pfchan->vt == &PortForwarding_channelvt);
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pf = container_of(pfchan, struct PortForwarding, chan);
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free_portfwd_state(pf);
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}
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|
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void portfwd_raw_setup(Channel *pfchan, Socket *s, SshChannel *sc)
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{
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struct PortForwarding *pf;
|
|
assert(pfchan->vt == &PortForwarding_channelvt);
|
|
pf = container_of(pfchan, struct PortForwarding, chan);
|
|
|
|
pf->s = s;
|
|
pf->c = sc;
|
|
}
|
|
|
|
/*
|
|
called when someone connects to the local port
|
|
*/
|
|
|
|
static int pfl_accepting(Plug *p, accept_fn_t constructor, accept_ctx_t ctx)
|
|
{
|
|
struct PortListener *pl = container_of(p, struct PortListener, plug);
|
|
struct PortForwarding *pf;
|
|
Channel *chan;
|
|
Plug *plug;
|
|
Socket *s;
|
|
const char *err;
|
|
|
|
chan = portfwd_raw_new(pl->cl, &plug, false);
|
|
s = constructor(ctx, plug);
|
|
if ((err = sk_socket_error(s)) != NULL) {
|
|
portfwd_raw_free(chan);
|
|
return 1;
|
|
}
|
|
|
|
pf = container_of(chan, struct PortForwarding, chan);
|
|
|
|
if (pl->is_dynamic) {
|
|
pf->s = s;
|
|
pf->socks_state = SOCKS_INITIAL;
|
|
pf->socksbuf = strbuf_new();
|
|
pf->socksbuf_consumed = 0;
|
|
pf->port = 0; /* "hostname" buffer is so far empty */
|
|
sk_set_frozen(s, false); /* we want to receive SOCKS _now_! */
|
|
} else {
|
|
pf->hostname = dupstr(pl->hostname);
|
|
pf->port = pl->port;
|
|
portfwd_raw_setup(
|
|
chan, s,
|
|
wrap_lportfwd_open(pl->cl, pf->hostname, pf->port, s, &pf->chan));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const PlugVtable PortListener_plugvt = {
|
|
.log = pfl_log,
|
|
.closing = pfl_closing,
|
|
.accepting = pfl_accepting,
|
|
};
|
|
|
|
/*
|
|
* Add a new port-forwarding listener from srcaddr:port -> desthost:destport.
|
|
*
|
|
* desthost == NULL indicates dynamic SOCKS port forwarding.
|
|
*
|
|
* On success, returns NULL and fills in *pl_ret. On error, returns a
|
|
* dynamically allocated error message string.
|
|
*/
|
|
static char *pfl_listen(const char *desthost, int destport,
|
|
const char *srcaddr, int port,
|
|
ConnectionLayer *cl, Conf *conf,
|
|
struct PortListener **pl_ret, int address_family)
|
|
{
|
|
const char *err;
|
|
struct PortListener *pl;
|
|
|
|
/*
|
|
* Open socket.
|
|
*/
|
|
pl = *pl_ret = new_portlistener_state();
|
|
pl->plug.vt = &PortListener_plugvt;
|
|
if (desthost) {
|
|
pl->hostname = dupstr(desthost);
|
|
pl->port = destport;
|
|
pl->is_dynamic = false;
|
|
} else
|
|
pl->is_dynamic = true;
|
|
pl->cl = cl;
|
|
|
|
pl->s = new_listener(srcaddr, port, &pl->plug,
|
|
!conf_get_bool(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;
|
|
}
|
|
|
|
static char *pfd_log_close_msg(Channel *chan)
|
|
{
|
|
return dupstr("Forwarded port closed");
|
|
}
|
|
|
|
static void pfd_close(struct PortForwarding *pf)
|
|
{
|
|
if (!pf)
|
|
return;
|
|
|
|
sk_close(pf->s);
|
|
free_portfwd_state(pf);
|
|
}
|
|
|
|
/*
|
|
* Terminate a listener.
|
|
*/
|
|
static void pfl_terminate(struct PortListener *pl)
|
|
{
|
|
if (!pl)
|
|
return;
|
|
|
|
sk_close(pl->s);
|
|
free_portlistener_state(pl);
|
|
}
|
|
|
|
static void pfd_set_input_wanted(Channel *chan, bool wanted)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
pf->input_wanted = wanted;
|
|
sk_set_frozen(pf->s, !pf->input_wanted);
|
|
}
|
|
|
|
static void pfd_chan_free(Channel *chan)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
pfd_close(pf);
|
|
}
|
|
|
|
/*
|
|
* Called to send data down the raw connection.
|
|
*/
|
|
static size_t pfd_send(
|
|
Channel *chan, bool is_stderr, const void *data, size_t len)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
return sk_write(pf->s, data, len);
|
|
}
|
|
|
|
static void pfd_send_eof(Channel *chan)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
sk_write_eof(pf->s);
|
|
}
|
|
|
|
static void pfd_open_confirmation(Channel *chan)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
|
|
pf->ready = true;
|
|
sk_set_frozen(pf->s, false);
|
|
sk_write(pf->s, NULL, 0);
|
|
if (pf->socksbuf) {
|
|
sshfwd_write(pf->c, pf->socksbuf->u + pf->socksbuf_consumed,
|
|
pf->socksbuf->len - pf->socksbuf_consumed);
|
|
strbuf_free(pf->socksbuf);
|
|
pf->socksbuf = NULL;
|
|
}
|
|
}
|
|
|
|
static void pfd_open_failure(Channel *chan, const char *errtext)
|
|
{
|
|
assert(chan->vt == &PortForwarding_channelvt);
|
|
PortForwarding *pf = container_of(chan, PortForwarding, chan);
|
|
|
|
logeventf(pf->cl->logctx,
|
|
"Forwarded connection refused by remote%s%s",
|
|
errtext ? ": " : "", errtext ? errtext : "");
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Code to manage the complete set of currently active port
|
|
* forwardings, and update it from Conf.
|
|
*/
|
|
|
|
struct PortFwdRecord {
|
|
enum { DESTROY, KEEP, CREATE } status;
|
|
int type;
|
|
unsigned sport, dport;
|
|
char *saddr, *daddr;
|
|
char *sserv, *dserv;
|
|
struct ssh_rportfwd *remote;
|
|
int addressfamily;
|
|
struct PortListener *local;
|
|
};
|
|
|
|
static int pfr_cmp(void *av, void *bv)
|
|
{
|
|
PortFwdRecord *a = (PortFwdRecord *) av;
|
|
PortFwdRecord *b = (PortFwdRecord *) bv;
|
|
int i;
|
|
if (a->type > b->type)
|
|
return +1;
|
|
if (a->type < b->type)
|
|
return -1;
|
|
if (a->addressfamily > b->addressfamily)
|
|
return +1;
|
|
if (a->addressfamily < b->addressfamily)
|
|
return -1;
|
|
if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
|
|
return i < 0 ? -1 : +1;
|
|
if (a->sport > b->sport)
|
|
return +1;
|
|
if (a->sport < b->sport)
|
|
return -1;
|
|
if (a->type != 'D') {
|
|
if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
|
|
return i < 0 ? -1 : +1;
|
|
if (a->dport > b->dport)
|
|
return +1;
|
|
if (a->dport < b->dport)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void pfr_free(PortFwdRecord *pfr)
|
|
{
|
|
/* Dispose of any listening socket. */
|
|
if (pfr->local)
|
|
pfl_terminate(pfr->local);
|
|
|
|
sfree(pfr->saddr);
|
|
sfree(pfr->daddr);
|
|
sfree(pfr->sserv);
|
|
sfree(pfr->dserv);
|
|
sfree(pfr);
|
|
}
|
|
|
|
struct PortFwdManager {
|
|
ConnectionLayer *cl;
|
|
Conf *conf;
|
|
tree234 *forwardings;
|
|
};
|
|
|
|
PortFwdManager *portfwdmgr_new(ConnectionLayer *cl)
|
|
{
|
|
PortFwdManager *mgr = snew(PortFwdManager);
|
|
|
|
mgr->cl = cl;
|
|
mgr->conf = NULL;
|
|
mgr->forwardings = newtree234(pfr_cmp);
|
|
|
|
return mgr;
|
|
}
|
|
|
|
void portfwdmgr_close(PortFwdManager *mgr, PortFwdRecord *pfr)
|
|
{
|
|
PortFwdRecord *realpfr = del234(mgr->forwardings, pfr);
|
|
if (realpfr == pfr)
|
|
pfr_free(pfr);
|
|
}
|
|
|
|
void portfwdmgr_close_all(PortFwdManager *mgr)
|
|
{
|
|
PortFwdRecord *pfr;
|
|
|
|
while ((pfr = delpos234(mgr->forwardings, 0)) != NULL)
|
|
pfr_free(pfr);
|
|
}
|
|
|
|
void portfwdmgr_free(PortFwdManager *mgr)
|
|
{
|
|
portfwdmgr_close_all(mgr);
|
|
freetree234(mgr->forwardings);
|
|
if (mgr->conf)
|
|
conf_free(mgr->conf);
|
|
sfree(mgr);
|
|
}
|
|
|
|
void portfwdmgr_config(PortFwdManager *mgr, Conf *conf)
|
|
{
|
|
PortFwdRecord *pfr;
|
|
int i;
|
|
char *key, *val;
|
|
|
|
if (mgr->conf)
|
|
conf_free(mgr->conf);
|
|
mgr->conf = conf_copy(conf);
|
|
|
|
/*
|
|
* Go through the existing port forwardings and tag them
|
|
* with status==DESTROY. Any that we want to keep will be
|
|
* re-enabled (status==KEEP) as we go through the
|
|
* configuration and find out which bits are the same as
|
|
* they were before.
|
|
*/
|
|
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++)
|
|
pfr->status = DESTROY;
|
|
|
|
for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
|
|
val != NULL;
|
|
val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
|
|
char *kp, *kp2, *vp, *vp2;
|
|
char address_family, type;
|
|
int sport, dport, sserv, dserv;
|
|
char *sports, *dports, *saddr, *host;
|
|
|
|
kp = key;
|
|
|
|
address_family = 'A';
|
|
type = 'L';
|
|
if (*kp == 'A' || *kp == '4' || *kp == '6')
|
|
address_family = *kp++;
|
|
if (*kp == 'L' || *kp == 'R')
|
|
type = *kp++;
|
|
|
|
if ((kp2 = host_strchr(kp, ':')) != NULL) {
|
|
/*
|
|
* There's a colon in the middle of the source port
|
|
* string, which means that the part before it is
|
|
* actually a source address.
|
|
*/
|
|
char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
|
|
saddr = host_strduptrim(saddr_tmp);
|
|
sfree(saddr_tmp);
|
|
sports = kp2+1;
|
|
} else {
|
|
saddr = NULL;
|
|
sports = kp;
|
|
}
|
|
sport = atoi(sports);
|
|
sserv = 0;
|
|
if (sport == 0) {
|
|
sserv = 1;
|
|
sport = net_service_lookup(sports);
|
|
if (!sport) {
|
|
logeventf(mgr->cl->logctx, "Service lookup failed for source"
|
|
" port \"%s\"", sports);
|
|
}
|
|
}
|
|
|
|
if (type == 'L' && !strcmp(val, "D")) {
|
|
/* dynamic forwarding */
|
|
host = NULL;
|
|
dports = NULL;
|
|
dport = -1;
|
|
dserv = 0;
|
|
type = 'D';
|
|
} else {
|
|
/* ordinary forwarding */
|
|
vp = val;
|
|
vp2 = vp + host_strcspn(vp, ":");
|
|
host = dupprintf("%.*s", (int)(vp2 - vp), vp);
|
|
if (*vp2)
|
|
vp2++;
|
|
dports = vp2;
|
|
dport = atoi(dports);
|
|
dserv = 0;
|
|
if (dport == 0) {
|
|
dserv = 1;
|
|
dport = net_service_lookup(dports);
|
|
if (!dport) {
|
|
logeventf(mgr->cl->logctx,
|
|
"Service lookup failed for destination"
|
|
" port \"%s\"", dports);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (sport && dport) {
|
|
/* Set up a description of the source port. */
|
|
pfr = snew(PortFwdRecord);
|
|
pfr->type = type;
|
|
pfr->saddr = saddr;
|
|
pfr->sserv = sserv ? dupstr(sports) : NULL;
|
|
pfr->sport = sport;
|
|
pfr->daddr = host;
|
|
pfr->dserv = dserv ? dupstr(dports) : NULL;
|
|
pfr->dport = dport;
|
|
pfr->local = NULL;
|
|
pfr->remote = NULL;
|
|
pfr->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
|
|
address_family == '6' ? ADDRTYPE_IPV6 :
|
|
ADDRTYPE_UNSPEC);
|
|
|
|
PortFwdRecord *existing = add234(mgr->forwardings, pfr);
|
|
if (existing != pfr) {
|
|
if (existing->status == DESTROY) {
|
|
/*
|
|
* We already have a port forwarding up and running
|
|
* with precisely these parameters. Hence, no need
|
|
* to do anything; simply re-tag the existing one
|
|
* as KEEP.
|
|
*/
|
|
existing->status = KEEP;
|
|
}
|
|
/*
|
|
* Anything else indicates that there was a duplicate
|
|
* in our input, which we'll silently ignore.
|
|
*/
|
|
pfr_free(pfr);
|
|
} else {
|
|
pfr->status = CREATE;
|
|
}
|
|
} else {
|
|
sfree(saddr);
|
|
sfree(host);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now go through and destroy any port forwardings which were
|
|
* not re-enabled.
|
|
*/
|
|
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++) {
|
|
if (pfr->status == DESTROY) {
|
|
char *message;
|
|
|
|
message = dupprintf("%s port forwarding from %s%s%d",
|
|
pfr->type == 'L' ? "local" :
|
|
pfr->type == 'R' ? "remote" : "dynamic",
|
|
pfr->saddr ? pfr->saddr : "",
|
|
pfr->saddr ? ":" : "",
|
|
pfr->sport);
|
|
|
|
if (pfr->type != 'D') {
|
|
char *msg2 = dupprintf("%s to %s:%d", message,
|
|
pfr->daddr, pfr->dport);
|
|
sfree(message);
|
|
message = msg2;
|
|
}
|
|
|
|
logeventf(mgr->cl->logctx, "Cancelling %s", message);
|
|
sfree(message);
|
|
|
|
/* pfr->remote or pfr->local may be NULL if setting up a
|
|
* forwarding failed. */
|
|
if (pfr->remote) {
|
|
/*
|
|
* Cancel the port forwarding at the server
|
|
* end.
|
|
*
|
|
* Actually closing the listening port on the server
|
|
* side may fail - because in SSH-1 there's no message
|
|
* in the protocol to request it!
|
|
*
|
|
* Instead, we simply remove the record of the
|
|
* forwarding from our local end, so that any
|
|
* connections the server tries to make on it are
|
|
* rejected.
|
|
*/
|
|
ssh_rportfwd_remove(mgr->cl, pfr->remote);
|
|
pfr->remote = NULL;
|
|
} else if (pfr->local) {
|
|
pfl_terminate(pfr->local);
|
|
pfr->local = NULL;
|
|
}
|
|
|
|
delpos234(mgr->forwardings, i);
|
|
pfr_free(pfr);
|
|
i--; /* so we don't skip one in the list */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* And finally, set up any new port forwardings (status==CREATE).
|
|
*/
|
|
for (i = 0; (pfr = index234(mgr->forwardings, i)) != NULL; i++) {
|
|
if (pfr->status == CREATE) {
|
|
char *sportdesc, *dportdesc;
|
|
sportdesc = dupprintf("%s%s%s%s%d%s",
|
|
pfr->saddr ? pfr->saddr : "",
|
|
pfr->saddr ? ":" : "",
|
|
pfr->sserv ? pfr->sserv : "",
|
|
pfr->sserv ? "(" : "",
|
|
pfr->sport,
|
|
pfr->sserv ? ")" : "");
|
|
if (pfr->type == 'D') {
|
|
dportdesc = NULL;
|
|
} else {
|
|
dportdesc = dupprintf("%s:%s%s%d%s",
|
|
pfr->daddr,
|
|
pfr->dserv ? pfr->dserv : "",
|
|
pfr->dserv ? "(" : "",
|
|
pfr->dport,
|
|
pfr->dserv ? ")" : "");
|
|
}
|
|
|
|
if (pfr->type == 'L') {
|
|
char *err = pfl_listen(pfr->daddr, pfr->dport,
|
|
pfr->saddr, pfr->sport,
|
|
mgr->cl, conf, &pfr->local,
|
|
pfr->addressfamily);
|
|
|
|
logeventf(mgr->cl->logctx,
|
|
"Local %sport %s forwarding to %s%s%s",
|
|
pfr->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
|
|
pfr->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
|
|
sportdesc, dportdesc,
|
|
err ? " failed: " : "", err ? err : "");
|
|
if (err)
|
|
sfree(err);
|
|
} else if (pfr->type == 'D') {
|
|
char *err = pfl_listen(NULL, -1, pfr->saddr, pfr->sport,
|
|
mgr->cl, conf, &pfr->local,
|
|
pfr->addressfamily);
|
|
|
|
logeventf(mgr->cl->logctx,
|
|
"Local %sport %s SOCKS dynamic forwarding%s%s",
|
|
pfr->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
|
|
pfr->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
|
|
sportdesc,
|
|
err ? " failed: " : "", err ? err : "");
|
|
|
|
if (err)
|
|
sfree(err);
|
|
} else {
|
|
const char *shost;
|
|
|
|
if (pfr->saddr) {
|
|
shost = pfr->saddr;
|
|
} else if (conf_get_bool(conf, CONF_rport_acceptall)) {
|
|
shost = "";
|
|
} else {
|
|
shost = "localhost";
|
|
}
|
|
|
|
pfr->remote = ssh_rportfwd_alloc(
|
|
mgr->cl, shost, pfr->sport, pfr->daddr, pfr->dport,
|
|
pfr->addressfamily, sportdesc, pfr, NULL);
|
|
|
|
if (!pfr->remote) {
|
|
logeventf(mgr->cl->logctx,
|
|
"Duplicate remote port forwarding to %s:%d",
|
|
pfr->daddr, pfr->dport);
|
|
pfr_free(pfr);
|
|
} else {
|
|
logeventf(mgr->cl->logctx, "Requesting remote port %s"
|
|
" forward to %s", sportdesc, dportdesc);
|
|
}
|
|
}
|
|
sfree(sportdesc);
|
|
sfree(dportdesc);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool portfwdmgr_listen(PortFwdManager *mgr, const char *host, int port,
|
|
const char *keyhost, int keyport, Conf *conf)
|
|
{
|
|
PortFwdRecord *pfr;
|
|
|
|
pfr = snew(PortFwdRecord);
|
|
pfr->type = 'L';
|
|
pfr->saddr = host ? dupstr(host) : NULL;
|
|
pfr->daddr = keyhost ? dupstr(keyhost) : NULL;
|
|
pfr->sserv = pfr->dserv = NULL;
|
|
pfr->sport = port;
|
|
pfr->dport = keyport;
|
|
pfr->local = NULL;
|
|
pfr->remote = NULL;
|
|
pfr->addressfamily = ADDRTYPE_UNSPEC;
|
|
|
|
PortFwdRecord *existing = add234(mgr->forwardings, pfr);
|
|
if (existing != pfr) {
|
|
/*
|
|
* We had this record already. Return failure.
|
|
*/
|
|
pfr_free(pfr);
|
|
return false;
|
|
}
|
|
|
|
char *err = pfl_listen(keyhost, keyport, host, port,
|
|
mgr->cl, conf, &pfr->local, pfr->addressfamily);
|
|
logeventf(mgr->cl->logctx,
|
|
"%s on port %s:%d to forward to client%s%s",
|
|
err ? "Failed to listen" : "Listening", host, port,
|
|
err ? ": " : "", err ? err : "");
|
|
if (err) {
|
|
sfree(err);
|
|
del234(mgr->forwardings, pfr);
|
|
pfr_free(pfr);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool portfwdmgr_unlisten(PortFwdManager *mgr, const char *host, int port)
|
|
{
|
|
PortFwdRecord pfr_key;
|
|
|
|
pfr_key.type = 'L';
|
|
/* Safe to cast the const away here, because it will only be used
|
|
* by pfr_cmp, which won't write to the string */
|
|
pfr_key.saddr = pfr_key.daddr = (char *)host;
|
|
pfr_key.sserv = pfr_key.dserv = NULL;
|
|
pfr_key.sport = pfr_key.dport = port;
|
|
pfr_key.local = NULL;
|
|
pfr_key.remote = NULL;
|
|
pfr_key.addressfamily = ADDRTYPE_UNSPEC;
|
|
|
|
PortFwdRecord *pfr = del234(mgr->forwardings, &pfr_key);
|
|
|
|
if (!pfr)
|
|
return false;
|
|
|
|
logeventf(mgr->cl->logctx, "Closing listening port %s:%d", host, port);
|
|
|
|
pfr_free(pfr);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* 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 *portfwdmgr_connect(PortFwdManager *mgr, Channel **chan_ret,
|
|
char *hostname, int port, SshChannel *c,
|
|
int addressfamily)
|
|
{
|
|
SockAddr *addr;
|
|
const char *err;
|
|
char *dummy_realhost = NULL;
|
|
struct PortForwarding *pf;
|
|
|
|
/*
|
|
* Try to find host.
|
|
*/
|
|
addr = name_lookup(hostname, port, &dummy_realhost, mgr->conf,
|
|
addressfamily, NULL, NULL);
|
|
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 = new_portfwd_state();
|
|
*chan_ret = &pf->chan;
|
|
pf->plug.vt = &PortForwarding_plugvt;
|
|
pf->chan.initial_fixed_window_size = 0;
|
|
pf->chan.vt = &PortForwarding_channelvt;
|
|
pf->input_wanted = true;
|
|
pf->ready = true;
|
|
pf->c = c;
|
|
pf->cl = mgr->cl;
|
|
pf->socks_state = SOCKS_NONE;
|
|
|
|
pf->s = new_connection(addr, dummy_realhost, port,
|
|
false, true, false, false, &pf->plug, mgr->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);
|
|
*chan_ret = NULL;
|
|
return err_ret;
|
|
}
|
|
|
|
return NULL;
|
|
}
|