4 files changed, 60 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index 18a975ad3..5b4ff341b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,8 @@
 20030510
  - (dtucker) Bug #318: Create ssh_prng_cmds.out during "make" rather than
    "make install".  Patch by roth@feep.net.
+ - (dtucker) Bug #536: Test for and work around openpty/controlling tty
+   problem on Linux (fixes "could not set controlling tty" errors).
 
 20030504
  - (dtucker) Bug #497: Move #include of bsd-cygwin_util.h to openbsd-compat.h.
@@ -1374,4 +1376,4 @@
      save auth method before monitor_reset_key_state(); bugzilla bug #284;
      ok provos@
 
-$Id: ChangeLog,v 1.2671 2003/05/10 06:48:23 dtucker Exp $
+$Id: ChangeLog,v 1.2672 2003/05/10 07:05:46 dtucker Exp $
diff --git a/acconfig.h b/acconfig.h
index 6164ecc8d..0a4706425 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -1,4 +1,4 @@
-/* $Id: acconfig.h,v 1.150 2003/05/02 10:48:21 dtucker Exp $ */
+/* $Id: acconfig.h,v 1.151 2003/05/10 07:05:46 dtucker Exp $ */
 
 #ifndef _CONFIG_H
 #define _CONFIG_H
@@ -374,8 +374,8 @@
 /* Some systems put this outside of libc */
 #undef HAVE_NANOSLEEP
 
-/* Pushing STREAMS modules incorrectly acquires a controlling TTY */
-#undef STREAMS_PUSH_ACQUIRES_CTTY
+/* Define if sshd somehow reacquires a controlling TTY after setsid() */
+#undef SSHD_ACQUIRES_CTTY
 
 /* Define if cmsg_type is not passed correctly */
 #undef BROKEN_CMSG_TYPE
diff --git a/configure.ac b/configure.ac
index d6726eaab..dee852854 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.115 2003/05/02 10:48:21 dtucker Exp $
+# $Id: configure.ac,v 1.116 2003/05/10 07:05:46 dtucker Exp $
 
 AC_INIT
 AC_CONFIG_SRCDIR([ssh.c])
@@ -188,15 +188,56 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
         AC_DEFINE(SETPROCTITLE_STRATEGY,PS_USE_CLOBBER_ARGV)
         AC_DEFINE(SETPROCTITLE_PS_PADDING, '\0')
         inet6_default_4in6=yes
-        AC_MSG_CHECKING(for broken cmsg_type)
+        # openpty can be in libutil, needed for controlling tty test
+        AC_SEARCH_LIBS(openpty, util)
+        # make sure that openpty does not reacquire controlling terminal
+        AC_MSG_CHECKING(if openpty correctly handles controlling tty)
+        AC_TRY_RUN(
+                [
+#include <stdio.h>
+#include <sys/fcntl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+int
+main()
+{
+        pid_t pid;
+        int fd, ptyfd, ttyfd, status;
+
+        pid = fork();
+        if (pid < 0) {          /* failed */
+                exit(1);
+        } else if (pid > 0) {   /* parent */
+                waitpid(pid, &status, 0);
+                if (WIFEXITED(status)) 
+                        exit(WEXITSTATUS(status));
+                else
+                        exit(2);
+        } else {                /* child */
+                close(0); close(1); close(2);
+                setsid();
+                openpty(&ptyfd, &ttyfd, NULL, NULL, NULL);
+                fd = open("/dev/tty", O_RDWR | O_NOCTTY);
+                if (fd >= 0)
+                        exit(3);        /* Acquired ctty: broken */
+                else
+                        exit(0);        /* Did not acquire ctty: OK */
+        }
+}
+                ],
+                [
+                        AC_MSG_RESULT(yes)
+                ],
+                [
+                        AC_MSG_RESULT(no)
+                        AC_DEFINE(SSHD_ACQUIRES_CTTY)
+                ]
+        )
         case `uname -r` in
-        2.0.*)
-                AC_MSG_RESULT(yes)
+        1.*|2.0.*)
                 AC_DEFINE(BROKEN_CMSG_TYPE)
                 ;;
-        *)
-                AC_MSG_RESULT(no)
-                ;;
         esac
         ;;
 mips-sony-bsd|mips-sony-newsos4)
@@ -230,7 +271,8 @@ mips-sony-bsd|mips-sony-newsos4)
         AC_DEFINE(LOGIN_NEEDS_UTMPX)
         AC_DEFINE(LOGIN_NEEDS_TERM)
         AC_DEFINE(PAM_TTY_KLUDGE)
-        AC_DEFINE(STREAMS_PUSH_ACQUIRES_CTTY)
+        # Pushing STREAMS modules will cause sshd to acquire a controlling tty.
+        AC_DEFINE(SSHD_ACQUIRES_CTTY)
         # hardwire lastlog location (can't detect it on some versions)
         conf_lastlog_location="/var/adm/lastlog"
         AC_MSG_CHECKING(for obsolete utmp and wtmp in solaris2.x)
diff --git a/sshd.c b/sshd.c
index 62b4f45f4..63070ac23 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1400,11 +1400,11 @@ main(int ac, char **av)
          * setlogin() affects the entire process group.  We don't
          * want the child to be able to affect the parent.
          */
-#if !defined(STREAMS_PUSH_ACQUIRES_CTTY)
+#if !defined(SSHD_ACQUIRES_CTTY)
         /*
-         * If setsid is called on Solaris, sshd will acquire the controlling
-         * terminal while pushing STREAMS modules. This will prevent the
-         * shell from acquiring it later.
+         * If setsid is called, on some platforms sshd will later acquire a
+         * controlling terminal which will result in "could not set
+         * controlling tty" errors.
          */
         if (!debug_flag && !inetd_flag && setsid() < 0)
                 error("setsid: %.100s", strerror(errno));