1 files changed, 81 insertions, 0 deletions
diff --git a/ncr.c b/ncr.c
new file mode 100644
index 0000000..b903fb8
--- /dev/null
+++ b/ncr.c
@@ -0,0 +1,81 @@
+ /*
+  * 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);
+}