зеркало из https://github.com/github/putty.git
1176 строки
35 KiB
C
1176 строки
35 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, int 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, int 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, 1);
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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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pfd_log,
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pfd_closing,
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pfd_receive,
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pfd_sent,
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NULL
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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 struct ChannelVtable PortForwarding_channelvt = {
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pfd_chan_free,
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pfd_open_confirmation,
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pfd_open_failure,
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pfd_send,
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pfd_send_eof,
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pfd_set_input_wanted,
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pfd_log_close_msg,
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chan_default_want_close,
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chan_no_exit_status,
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chan_no_exit_signal,
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chan_no_exit_signal_numeric,
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chan_no_run_shell,
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chan_no_run_command,
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chan_no_run_subsystem,
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chan_no_enable_x11_forwarding,
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chan_no_enable_agent_forwarding,
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chan_no_allocate_pty,
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chan_no_set_env,
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chan_no_send_break,
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chan_no_send_signal,
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chan_no_change_window_size,
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chan_no_request_response,
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};
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Channel *portfwd_raw_new(ConnectionLayer *cl, Plug **plug)
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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 = false;
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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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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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void portfwd_raw_setup(Channel *pfchan, Socket *s, SshChannel *sc)
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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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pf->s = s;
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pf->c = sc;
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}
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/*
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called when someone connects to the local port
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*/
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static int pfl_accepting(Plug *p, accept_fn_t constructor, accept_ctx_t ctx)
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{
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struct PortListener *pl = container_of(p, struct PortListener, plug);
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struct PortForwarding *pf;
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Channel *chan;
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Plug *plug;
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Socket *s;
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const char *err;
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chan = portfwd_raw_new(pl->cl, &plug);
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s = constructor(ctx, plug);
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if ((err = sk_socket_error(s)) != NULL) {
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portfwd_raw_free(chan);
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return 1;
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}
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pf = container_of(chan, struct PortForwarding, chan);
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if (pl->is_dynamic) {
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pf->s = s;
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pf->socks_state = SOCKS_INITIAL;
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pf->socksbuf = strbuf_new();
|
|
pf->socksbuf_consumed = 0;
|
|
pf->port = 0; /* "hostname" buffer is so far empty */
|
|
sk_set_frozen(s, 0); /* 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 = {
|
|
pfl_log,
|
|
pfl_closing,
|
|
NULL, /* recv */
|
|
NULL, /* send */
|
|
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, 0);
|
|
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;
|
|
}
|
|
|
|
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);
|
|
} else if (pfr->local) {
|
|
pfl_terminate(pfr->local);
|
|
}
|
|
|
|
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;
|
|
}
|