contrib/tcp_wrappers/ptx.c

   1  /*
   2   * The Dynix/PTX TLI implementation is not quite compatible with System V
   3   * Release 4. Some important functions are not present so we are limited to
   4   * IP-based services.
   5   *
   6   * Diagnostics are reported through syslog(3).
   7   *
   8   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
   9   */
  10
  11 #ifndef lint
  12 static char sccsid[] = "@(#) ptx.c 1.3 94/12/28 17:42:38";
  13 #endif
  14
  15 #ifdef PTX
  16
  17 /* System libraries. */
  18
  19 #include <sys/types.h>
  20 #include <sys/tiuser.h>
  21 #include <sys/socket.h>
  22 #include <stropts.h>
  23 #include <netinet/in.h>
  24 #include <netdb.h>
  25 #include <stdio.h>
  26 #include <syslog.h>
  27
  28 /* Local stuff. */
  29
  30 #include "tcpd.h"
  31
  32 /* Forward declarations. */
  33
  34 static void ptx_sink();
  35
  36 /* tli_host - determine TLI endpoint info, PTX version */
  37
  38 void    tli_host(request)
  39 struct request_info *request;
  40 {
  41     static struct sockaddr_in client;
  42     static struct sockaddr_in server;
  43
  44     /*
  45      * getpeerinaddr() was suggested by someone at Sequent. It seems to work
  46      * with connection-oriented (TCP) services such as rlogind and telnetd,
  47      * but it returns 0.0.0.0 with datagram (UDP) services. No problem: UDP
  48      * needs special treatment anyway, in case we must refuse service.
  49      */
  50
  51     if (getpeerinaddr(request->fd, &client, sizeof(client)) == 0
  52         && client.sin_addr.s_addr != 0) {
  53         request->client->sin = &client;
  54         if (getmyinaddr(request->fd, &server, sizeof(server)) == 0) {
  55             request->server->sin = &server;
  56         } else {
  57             tcpd_warn("warning: getmyinaddr: %m");
  58         }
  59         sock_methods(request);
  60
  61     } else {
  62
  63         /*
  64          * Another suggestion was to temporarily switch to the socket
  65          * interface, identify the endpoint addresses with socket calls, then
  66          * to switch back to TLI. This seems to works OK with UDP services,
  67          * which is exactly what we should be looking at right now.
  68          */
  69
  70 #define SWAP_MODULE(f, old, new) (ioctl(f, I_POP, old), ioctl(f, I_PUSH, new))
  71
  72         if (SWAP_MODULE(request->fd, "timod", "sockmod") != 0)
  73             tcpd_warn("replace timod by sockmod: %m");
  74         sock_host(request);
  75         if (SWAP_MODULE(request->fd, "sockmod", "timod") != 0)
  76             tcpd_warn("replace sockmod by timod: %m");
  77         if (request->sink != 0)
  78             request->sink = ptx_sink;
  79     }
  80 }
  81
  82 /* ptx_sink - absorb unreceived IP datagram */
  83
  84 static void ptx_sink(fd)
  85 int     fd;
  86 {
  87     char    buf[BUFSIZ];
  88     struct sockaddr sa;
  89     int     size = sizeof(sa);
  90
  91     /*
  92      * Eat up the not-yet received datagram. Where needed, switch to the
  93      * socket programming interface.
  94      */
  95
  96     if (ioctl(fd, I_FIND, "timod") != 0)
  97         ioctl(fd, I_POP, "timod");
  98     if (ioctl(fd, I_FIND, "sockmod") == 0)
  99         ioctl(fd, I_PUSH, "sockmod");
 100     (void) recvfrom(fd, buf, sizeof(buf), 0, &sa, &size);
 101 }
 102
 103 #endif /* PTX */