tcp-wrappers/ncr.c

82 lines
2.5 KiB
C

/*
* This part for NCR UNIX with is from Andrew Maffei (arm@aqua.whoi.edu). It
* assumes TLI throughout. In order to look up endpoint address information
* we must talk to the "timod" streams module. For some reason "timod" wants
* to sit directly on top of the device driver. Therefore we pop off all
* streams modules except the driver, install the "timod" module so that we
* can figure out network addresses, and then restore the original state.
*/
#ifndef lint
static char sccsid[] = "@(#) ncr.c 1.1 94/12/28 17:42:34";
#endif
#include <sys/types.h>
#include <stdio.h>
#include <syslog.h>
#include <sys/tiuser.h>
#include <stropts.h>
#include <sys/conf.h>
#include "tcpd.h"
#define MAX_MODULE_COUNT 10 /* XXX */
/* fromhost - tear down the streams stack then rebuild it */
void fromhost(request)
struct request_info *request;
{
int i;
int num_mod;
struct str_list str_list;
struct str_mlist mod_buffer[MAX_MODULE_COUNT];
int fd = request->fd;
str_list.sl_nmods = MAX_MODULE_COUNT;
str_list.sl_modlist = &mod_buffer[0];
/*
* On systems with WIN streams support we have to be careful about what
* is on the stream we are passed. This code POPs off all modules above
* the pseudo driver, pushes timod, gets the host address information,
* pops timod and then pushes all modules back on the stream.
*
* Some state may be lost in this process. /usr/etc/tlid seems to do special
* things to the stream depending on the TCP port being serviced. (not a
* very nice thing to do!). It is unclear what to do if this code breaks
* - the stream may be left in an unknown condition.
*/
if ((num_mod = ioctl(fd, I_LIST, NULL)) < 0)
tcpd_warn("fromhost: LIST failed: %m");
if (ioctl(fd, I_LIST, &str_list) < 0)
tcpd_warn("fromhost: LIST failed: %m");
/*
* POP stream modules except for the driver.
*/
for (i = 0; i < num_mod - 1; i++)
if (ioctl(fd, I_POP, 0) < 0)
tcpd_warn("fromhost: POP %s: %m", mod_buffer[i].l_name);
/*
* PUSH timod so that host address ioctls can be executed.
*/
if (ioctl(fd, I_PUSH, "timod") < 0)
tcpd_warn("fromhost: PUSH timod: %m");
tli_host(request);
/*
* POP timod, we're done with it now.
*/
if (ioctl(fd, I_POP, 0) < 0)
tcpd_warn("fromhost: POP timod: %m");
/*
* Restore stream modules.
*/
for (i = num_mod - 2; i >= 0; i--)
if (ioctl(fd, I_PUSH, mod_buffer[i].l_name) < 0)
tcpd_warn("fromhost: PUSH %s: %m", mod_buffer[i].l_name);
}