problem with kerberos telnetd on AIX

[Donn Cave]

Quoth David McWilliams <davem at ncsa.uiuc.edu>:
...
| Does anyone know if there is a version of kerberos telnetd with a call to 
| setpcred?  If not, do any of you telnetd experts have any suggestions for 
| how to modify it?

As Jeffrey Altman pointed out, this goes in appl/bsd/login.c

I'm appending a little wad of junk from our login.c, where my
extensive changes have been mostly but not entirely devoted to
accommodating AIX peculiarities.  It is excerpted from a context
diff, but will not work as input for "patch".

There is a little documentation in comments.  If I remember right,
the last change allows /etc/environment to set PATH.

	Donn Cave, University Computing Services, University of Washington
	donn at u.washington.edu
-----------------------------
*** 223,231 ****
  #ifdef _IBMR2
  #include <usersec.h>
  #include <sys/id.h>
  #endif

! #if defined(_AIX)
  #define PRIO_OFFSET 20
  #else
  #define PRIO_OFFSET 0
--- 228,237 ----
  #ifdef _IBMR2
  #include <usersec.h>
  #include <sys/id.h>
+ #include <uinfo.h>
  #endif

! #if defined(_AIX) && !defined(_AIX41)
  #define PRIO_OFFSET 20
  #else
  #define PRIO_OFFSET 0
***************
*** anywhere ****
+ #ifdef _AIX
+ /*
+ **  More AIXisms.
+ **  usrinfo() sets a privileged version of the environment.
+ **  It's hard to say how important these are, but one known
+ **  application is getlogin(), which is called from ftp.
+ **  Without the following, this will erroneously conclude
+ **  that you are "root".  (Harmless but annoying.)
+ **  The data is concatenated NUL terminated strings, with
+ **  an extra NUL to terminate the list.
+ */
+ static void
+ aixpenv(const char *name, const char *ttyn)
+ {
+     char stuff[512], *cp;
+     int len;
+     cp = stuff;
+     memcpy(cp, "LOGNAME=", 8); cp += 8;
+     len = strlen(pwd->pw_name);
+     if (len > 16)
+       len = 16;
+     memcpy(cp, pwd->pw_name, len); cp += len;
+     *cp++ = 0;
+     memcpy(cp, "NAME=", 5); cp += 5;
+     memcpy(cp, pwd->pw_name, len); cp += len;
+     *cp++ = 0;
+     memcpy(cp, "TTY=", 4); cp += 4;
+     len = strlen(ttyn);
+     if (len > 16)
+       len = 16;
+     memcpy(cp, ttyn, len); cp += len;
+     *cp++ = 0;
+     *cp++ = 0;
+     usrinfo(SETUINFO, stuff, cp - stuff);
+ }
+ #endif
+
***************
*** 1483,1489 ****

        /* this will set the PGID to the PID. */
  #ifdef HAVE_SETPGID
!       if (setpgid(p,p) < 0)
            perror("login.krb5: setpgid");
  #elif defined(SETPGRP_TWOARG)
        if (setpgrp(p,p) < 0)
--- 1676,1683 ----

        /* this will set the PGID to the PID. */
  #ifdef HAVE_SETPGID
!       /* AIX 4.3 complains ... possibly because p is session leader?? DC */
!       if (getpgid(0) != p && setpgid(p,p) < 0)
            perror("login.krb5: setpgid");
  #elif defined(SETPGRP_TWOARG)
        if (setpgrp(p,p) < 0)
***************
*** 1609,1614 ****
--- 1803,1812 ----
      if (setlogin(pwd->pw_name) < 0)
        syslog(LOG_ERR, "setlogin() failure %d",errno);
  #endif
+ #ifdef _AIX
+     aixpenv(pwd->pw_name, ttyn);
+     setpcred(pwd->pw_name, 0);
+ #endif

  #ifdef        HAVE_SETLUID
        /*
***************
*** 1737,1743 ****
        setenv("KRB5CCNAME", ccname, 1);

      setenv("HOME", pwd->pw_dir, 1);
!     setenv("PATH", LPATH, 1);
      setenv("USER", pwd->pw_name, 1);
      setenv("SHELL", pwd->pw_shell, 1);

--- 1935,1941 ----
        setenv("KRB5CCNAME", ccname, 1);

      setenv("HOME", pwd->pw_dir, 1);
!     setenv("PATH", LPATH, 0);
      setenv("USER", pwd->pw_name, 1);
      setenv("SHELL", pwd->pw_shell, 1);