tcp-accept.c

   1 /*
   2  * Dropbear SSH
   3  *
   4  * Copyright (c) 2002,2003 Matt Johnston
   5  * All rights reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE. */
  24
  25 #include "includes.h"
  26 #include "ssh.h"
  27 #include "tcpfwd.h"
  28 #include "dbutil.h"
  29 #include "session.h"
  30 #include "buffer.h"
  31 #include "packet.h"
  32 #include "listener.h"
  33 #include "runopts.h"
  34
  35 #ifdef DROPBEAR_TCP_ACCEPT
  36
  37 static void cleanup_tcp(struct Listener *listener) {
  38
  39         struct TCPListener *tcpinfo = (struct TCPListener*)(listener->typedata);
  40
  41         m_free(tcpinfo->sendaddr);
  42         m_free(tcpinfo->listenaddr);
  43         m_free(tcpinfo);
  44 }
  45
  46 static void tcp_acceptor(struct Listener *listener, int sock) {
  47
  48         int fd;
  49         struct sockaddr_storage addr;
  50         socklen_t len;
  51         char ipstring[NI_MAXHOST], portstring[NI_MAXSERV];
  52         struct TCPListener *tcpinfo = (struct TCPListener*)(listener->typedata);
  53
  54         len = sizeof(addr);
  55
  56         fd = accept(sock, (struct sockaddr*)&addr, &len);
  57         if (fd < 0) {
  58                 return;
  59         }
  60
  61         if (getnameinfo((struct sockaddr*)&addr, len, ipstring, sizeof(ipstring),
  62                                 portstring, sizeof(portstring),
  63                                 NI_NUMERICHOST | NI_NUMERICSERV) != 0) {
  64                 return;
  65         }
  66
  67         if (send_msg_channel_open_init(fd, tcpinfo->chantype) == DROPBEAR_SUCCESS) {
  68                 unsigned char* addr = NULL;
  69                 unsigned int port = 0;
  70
  71                 if (tcpinfo->tcp_type == direct) {
  72                         /* "direct-tcpip" */
  73                         /* host to connect, port to connect */
  74                         addr = tcpinfo->sendaddr;
  75                         port = tcpinfo->sendport;
  76                 } else {
  77                         dropbear_assert(tcpinfo->tcp_type == forwarded);
  78                         /* "forwarded-tcpip" */
  79                         /* address that was connected, port that was connected */
  80                         addr = tcpinfo->listenaddr;
  81                         port = tcpinfo->listenport;
  82                 }
  83
  84                 buf_putstring(ses.writepayload, addr, strlen(addr));
  85                 buf_putint(ses.writepayload, port);
  86
  87                 /* originator ip */
  88                 buf_putstring(ses.writepayload, ipstring, strlen(ipstring));
  89                 /* originator port */
  90                 buf_putint(ses.writepayload, atol(portstring));
  91
  92                 encrypt_packet();
  93
  94         } else {
  95                 /* XXX debug? */
  96                 close(fd);
  97         }
  98 }
  99
 100 int listen_tcpfwd(struct TCPListener* tcpinfo) {
 101
 102         char portstring[NI_MAXSERV];
 103         int socks[DROPBEAR_MAX_SOCKS];
 104         struct Listener *listener = NULL;
 105         int nsocks;
 106         char* errstring = NULL;
 107
 108         TRACE(("enter listen_tcpfwd"))
 109
 110         /* first we try to bind, so don't need to do so much cleanup on failure */
 111         snprintf(portstring, sizeof(portstring), "%d", tcpinfo->listenport);
 112
 113         nsocks = dropbear_listen(tcpinfo->listenaddr, portstring, socks,
 114                         DROPBEAR_MAX_SOCKS, &errstring, &ses.maxfd);
 115         if (nsocks < 0) {
 116                 dropbear_log(LOG_INFO, "TCP forward failed: %s", errstring);
 117                 m_free(errstring);
 118                 TRACE(("leave listen_tcpfwd: dropbear_listen failed"))
 119                 return DROPBEAR_FAILURE;
 120         }
 121         m_free(errstring);
 122
 123         /* new_listener will close the socks if it fails */
 124         listener = new_listener(socks, nsocks, CHANNEL_ID_TCPFORWARDED, tcpinfo,
 125                         tcp_acceptor, cleanup_tcp);
 126
 127         if (listener == NULL) {
 128                 TRACE(("leave listen_tcpfwd: listener failed"))
 129                 return DROPBEAR_FAILURE;
 130         }
 131
 132         TRACE(("leave listen_tcpfwd: success"))
 133         return DROPBEAR_SUCCESS;
 134 }
 135
 136 #endif /* DROPBEAR_TCP_ACCEPT */