/*

 * Dropbear SSH

 * 

 * Copyright (c) 2002,2003 Matt Johnston

 * All rights reserved.

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 * 

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE. */

#include "includes.h"

#include "dbutil.h"

#include "tcpfwd.h"

#include "channel.h"

#include "runopts.h"

#include "session.h"

#include "ssh.h"

#include "netio.h"

#if DROPBEAR_CLI_REMOTETCPFWD

static int newtcpforwarded(struct Channel * channel);

const struct ChanType cli_chan_tcpremote = {

  "forwarded-tcpip",

  newtcpforwarded,

  NULL,

  NULL,

  NULL,

  NULL

};

#endif

#if DROPBEAR_CLI_LOCALTCPFWD

static int cli_localtcp(const char* listenaddr, 

    unsigned int listenport, 

    const char* remoteaddr,

    unsigned int remoteport);

static const struct ChanType cli_chan_tcplocal = {

  "direct-tcpip",

  NULL,

  NULL,

  NULL,

  NULL,

  NULL

};

#endif

#if DROPBEAR_CLI_ANYTCPFWD

static void fwd_failed(const char* format, ...) ATTRIB_PRINTF(1,2);

static void fwd_failed(const char* format, ...)

{

  va_list param;

  va_start(param, format);

  if (cli_opts.exit_on_fwd_failure) {

    _dropbear_exit(EXIT_FAILURE, format, param);

  } else {

    _dropbear_log(LOG_WARNING, format, param);

  }

  va_end(param);

}

#endif

#if DROPBEAR_CLI_LOCALTCPFWD

void setup_localtcp() {

  m_list_elem *iter;

  int ret;

  TRACE(("enter setup_localtcp"))

  for (iter = cli_opts.localfwds->first; iter; iter = iter->next) {

    struct TCPFwdEntry * fwd = (struct TCPFwdEntry*)iter->item;

    ret = cli_localtcp(

        fwd->listenaddr,

        fwd->listenport,

        fwd->connectaddr,

        fwd->connectport);

    if (ret == DROPBEAR_FAILURE) {

      fwd_failed("Failed local port forward %s:%d:%s:%d",

          fwd->listenaddr,

          fwd->listenport,

          fwd->connectaddr,

          fwd->connectport);

    }    

  }

  TRACE(("leave setup_localtcp"))

}

static int cli_localtcp(const char* listenaddr, 

    unsigned int listenport, 

    const char* remoteaddr,

    unsigned int remoteport) {

  struct TCPListener* tcpinfo = NULL;

  int ret;

  TRACE(("enter cli_localtcp: %d %s %d", listenport, remoteaddr,

        remoteport));

  tcpinfo = (struct TCPListener*)m_malloc(sizeof(struct TCPListener));

  tcpinfo->sendaddr = m_strdup(remoteaddr);

  tcpinfo->sendport = remoteport;

  if (listenaddr)

  {

    tcpinfo->listenaddr = m_strdup(listenaddr);

  }

  else

  {

    if (opts.listen_fwd_all) {

      tcpinfo->listenaddr = m_strdup("");

    } else {

      tcpinfo->listenaddr = m_strdup("localhost");

    }

  }

  tcpinfo->listenport = listenport;

  tcpinfo->chantype = &cli_chan_tcplocal;

  tcpinfo->tcp_type = direct;

  ret = listen_tcpfwd(tcpinfo, NULL);

  if (ret == DROPBEAR_FAILURE) {

    m_free(tcpinfo);

  }

  TRACE(("leave cli_localtcp: %d", ret))

  return ret;

}

#endif /* DROPBEAR_CLI_LOCALTCPFWD */

#if DROPBEAR_CLI_REMOTETCPFWD

static void send_msg_global_request_remotetcp(const char *addr, int port) {

  TRACE(("enter send_msg_global_request_remotetcp"))

  CHECKCLEARTOWRITE();

  buf_putbyte(ses.writepayload, SSH_MSG_GLOBAL_REQUEST);

  buf_putstring(ses.writepayload, "tcpip-forward", 13);

  buf_putbyte(ses.writepayload, 1); /* want_reply */

  buf_putstring(ses.writepayload, addr, strlen(addr));

  buf_putint(ses.writepayload, port);

  encrypt_packet();

  TRACE(("leave send_msg_global_request_remotetcp"))

}

/* The only global success/failure messages are for remotetcp.

 * Since there isn't any identifier in these messages, we have to rely on them

 * being in the same order as we sent the requests. This is the ordering

 * of the cli_opts.remotefwds list.

 * If the requested remote port is 0 the listen port will be

 * dynamically allocated by the server and the port number will be returned

 * to client and the port number reported to the user. */

void cli_recv_msg_request_success() {

  /* We just mark off that we have received the reply,

   * so that we can report failure for later ones. */

  m_list_elem * iter = NULL;

  for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {

    struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;

    if (!fwd->have_reply) {

      fwd->have_reply = 1;

      if (fwd->listenport == 0) {

        /* The server should let us know which port was allocated if we requested port 0 */

        int allocport = buf_getint(ses.payload);

        if (allocport > 0) {

          fwd->listenport = allocport;

          dropbear_log(LOG_INFO, "Allocated port %d for remote forward to %s:%d", 

              allocport, fwd->connectaddr, fwd->connectport);

        }

      }

      return;

    }

  }

}

void cli_recv_msg_request_failure() {

  m_list_elem *iter;

  for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {

    struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;

    if (!fwd->have_reply) {

      fwd->have_reply = 1;

      fwd_failed("Remote TCP forward request failed (port %d -> %s:%d)",

          fwd->listenport,

          fwd->connectaddr,

          fwd->connectport);

      return;

    }

  }

}

void setup_remotetcp() {

  m_list_elem *iter;

  TRACE(("enter setup_remotetcp"))

  for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {

    struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;

    if (!fwd->listenaddr)

    {

      /* we store the addresses so that we can compare them

         when the server sends them back */

      if (opts.listen_fwd_all) {

        fwd->listenaddr = m_strdup("");

      } else {

        fwd->listenaddr = m_strdup("localhost");

      }

    }

    send_msg_global_request_remotetcp(fwd->listenaddr, fwd->listenport);

  }

  TRACE(("leave setup_remotetcp"))

}

static int newtcpforwarded(struct Channel * channel) {

  char *origaddr = NULL;

  unsigned int origport;

  m_list_elem * iter = NULL;

  struct TCPFwdEntry *fwd = NULL;

  char portstring[NI_MAXSERV];

  int err = SSH_OPEN_ADMINISTRATIVELY_PROHIBITED;

  origaddr = buf_getstring(ses.payload, NULL);

  origport = buf_getint(ses.payload);

  /* Find which port corresponds. First try and match address as well as port,

  in case they want to forward different ports separately ... */

  for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {

    fwd = (struct TCPFwdEntry*)iter->item;

    if (origport == fwd->listenport

        && strcmp(origaddr, fwd->listenaddr) == 0) {

      break;

    }

  }

  if (!iter)

  {

    /* ... otherwise try to generically match the only forwarded port 

    without address (also handles ::1 vs 127.0.0.1 vs localhost case).

    rfc4254 is vague about the definition of "address that was connected" */

    for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {

      fwd = (struct TCPFwdEntry*)iter->item;

      if (origport == fwd->listenport) {

        break;

      }

    }

  }

  if (iter == NULL || fwd == NULL) {

    /* We didn't request forwarding on that port */

    cleantext(origaddr);

    dropbear_log(LOG_INFO, "Server sent unrequested forward from \"%s:%d\"", 

                origaddr, origport);

    goto out;

  }

  snprintf(portstring, sizeof(portstring), "%u", fwd->connectport);

  channel->conn_pending = connect_remote(fwd->connectaddr, portstring, channel_connect_done,

    channel, NULL, NULL, DROPBEAR_PRIO_NORMAL);

  err = SSH_OPEN_IN_PROGRESS;

out:

  m_free(origaddr);

  TRACE(("leave newtcpdirect: err %d", err))

  return err;

}

#endif /* DROPBEAR_CLI_REMOTETCPFWD */