- markus@cvs.openbsd.org 2001/10/09 21:59:41

     [channels.c channels.h serverloop.c session.c session.h]
     simplify session close: no more delayed session_close, no more blocking wait() calls.

6 files changed, 45 insertions, 69 deletions

diff --git a/ChangeLog b/ChangeLog
index 2eda5e1b3..9fd4abbb1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -44,6 +44,10 @@
      [serverloop.c]
      close all channels if the connection to the remote host has been closed,
      should fix sshd's hanging with WCHAN==wait
+   - markus@cvs.openbsd.org 2001/10/09 21:59:41
+     [channels.c channels.h serverloop.c session.c session.h]
+     simplify session close: no more delayed session_close, no more 
+     blocking wait() calls.
 
 20011007
  - (bal) ssh-copy-id corrected permissions for .ssh/ and authorized_keys.
@@ -6689,4 +6693,4 @@
  - Wrote replacements for strlcpy and mkdtemp
  - Released 1.0pre1
 
-$Id: ChangeLog,v 1.1597 2001/10/10 05:08:36 djm Exp $
+$Id: ChangeLog,v 1.1598 2001/10/10 05:14:37 djm Exp $
diff --git a/channels.c b/channels.c
index aaa0ea579..04efd7287 100644
--- a/channels.c
+++ b/channels.c
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.138 2001/10/08 11:48:57 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.139 2001/10/09 21:59:41 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -359,22 +359,6 @@ channel_free_all(void)
                         channel_free(channels[i]);
 }
 
-void
-channel_detach_all(void)
-{
-        int i;
-        Channel *c;
-
-        for (i = 0; i < channels_alloc; i++) {
-                c = channels[i];
-                if (c != NULL && c->detach_user != NULL) {
-                        debug("channel_detach_all: channel %d", c->self);
-                        c->detach_user(c->self, NULL);
-                        c->detach_user = NULL;
-                }
-        }
-}
-
 /*
  * Closes the sockets/fds of all channels.  This is used to close extra file
  * descriptors after a fork.
diff --git a/channels.h b/channels.h
index 49a9df9dd..090d2ca6e 100644
--- a/channels.h
+++ b/channels.h
@@ -32,7 +32,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-/* RCSID("$OpenBSD: channels.h,v 1.48 2001/10/07 17:49:40 markus Exp $"); */
+/* RCSID("$OpenBSD: channels.h,v 1.49 2001/10/09 21:59:41 markus Exp $"); */
 
 #ifndef CHANNEL_H
 #define CHANNEL_H
@@ -143,7 +143,6 @@ Channel *channel_new(char *, int, int, int, int, int, int, int, char *, int);
 void     channel_set_fds(int, int, int, int, int, int);
 void     channel_free(Channel *);
 void     channel_free_all(void);
-void     channel_detach_all(void);
 void     channel_stop_listening(void);
 
 void     channel_send_open(int);
@@ -177,7 +176,6 @@ void     channel_output_poll(void);
 
 int      channel_not_very_much_buffered_data(void);
 void     channel_close_all(void);
-void     channel_free_all(void);
 int      channel_still_open(void);
 char    *channel_open_message(void);
 int      channel_find_open(void);
diff --git a/serverloop.c b/serverloop.c
index d7282fe2a..8a82af55b 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: serverloop.c,v 1.80 2001/10/09 19:51:18 markus Exp $");
+RCSID("$OpenBSD: serverloop.c,v 1.81 2001/10/09 21:59:41 markus Exp $");
 
 #include "xmalloc.h"
 #include "packet.h"
@@ -674,6 +674,7 @@ server_loop2(Authctxt *authctxt)
         fd_set *readset = NULL, *writeset = NULL;
         int rekeying = 0, max_fd, status, nalloc = 0;
         pid_t pid;
+        sigset_t oset, nset;
 
         debug("Entering interactive session for SSH2.");
 
@@ -696,12 +697,17 @@ server_loop2(Authctxt *authctxt)
                         channel_output_poll();
                 wait_until_can_do_something(&readset, &writeset, &max_fd,
                     &nalloc, 0);
+
+                /* block SIGCHLD while we check for dead children */
+                sigemptyset(&nset);
+                sigaddset(&nset, SIGCHLD);
+                sigprocmask(SIG_BLOCK, &nset, &oset);
                 if (child_terminated) {
                         while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
                                 session_close_by_pid(pid, status);
-                        /* XXX race */
                         child_terminated = 0;
                 }
+                sigprocmask(SIG_SETMASK, &oset, NULL);
                 if (!rekeying)
                         channel_after_select(readset, writeset);
                 process_input(readset);
@@ -709,35 +715,21 @@ server_loop2(Authctxt *authctxt)
                         break;
                 process_output(writeset);
         }
-        /* close all channels, no more reads and writes */
-        channel_close_all();
-
         if (readset)
                 xfree(readset);
         if (writeset)
                 xfree(writeset);
 
-        mysignal(SIGCHLD, SIG_DFL);
+        /* free all channels, no more reads and writes */
+        channel_free_all();
 
-        /* collect dead children */
+        /* collect remaining dead children, XXX not necessary? */
+        mysignal(SIGCHLD, SIG_DFL);
         while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
                 session_close_by_pid(pid, status);
-        /*
-         * there is a race between channel_detach_all() killing remaining
-         * children and children dying before kill()
-         */
-        channel_detach_all();
-
-        while (session_have_children()) {
-                pid = waitpid(-1, &status, 0);
-                if (pid > 0)
-                        session_close_by_pid(pid, status);
-                else {
-                        error("waitpid returned %d: %s", pid, strerror(errno));
-                        break;
-                }
-        }
-        channel_free_all();
+
+        /* close remaining sessions, e.g remove wtmp entries */
+        session_close_all();
 }
 
 static void
diff --git a/session.c b/session.c
index c1305da6a..0d6ebdaea 100644
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.105 2001/10/09 19:32:49 markus Exp $");
+RCSID("$OpenBSD: session.c,v 1.106 2001/10/09 21:59:41 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -1949,22 +1949,6 @@ session_close_by_pid(pid_t pid, int status)
         session_close(s);
 }
 
-int
-session_have_children(void)
-{
-        int i;
-
-        for(i = 0; i < MAX_SESSIONS; i++) {
-                Session *s = &sessions[i];
-                if (s->used && s->pid != -1) {
-                        debug("session_have_children: id %d pid %d", i, s->pid);
-                        return 1;
-                }
-        }
-        debug("session_have_children: no more children");
-        return 0;
-}
-
 /*
  * this is called when a channel dies before
  * the session 'child' itself dies
@@ -1982,15 +1966,29 @@ session_close_by_channel(int id, void *arg)
         s->chanid = -1;
 
         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
-        if (s->pid == 0) {
-                /* close session immediately */
-                session_close(s);
-        } else {
-                /* notify child, delay session cleanup */
-                if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
+        if (s->pid != 0) {
+                /* notify child */
+                if (kill(s->pid, SIGHUP) < 0)
                         error("session_close_by_channel: kill %d: %s",
                             s->pid, strerror(errno));
         }
+        session_close(s);
+}
+
+void
+session_close_all(void)
+{
+        int i;
+        for(i = 0; i < MAX_SESSIONS; i++) {
+                Session *s = &sessions[i];
+                if (s->used) {
+                        if (s->chanid != -1) {
+                                channel_cancel_cleanup(s->chanid);
+                                s->chanid = -1;
+                        }
+                        session_close(s);
+                }
+        }
 }
 
 static char *
diff --git a/session.h b/session.h
index a04fa6f2b..d2b0d9364 100644
--- a/session.h
+++ b/session.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: session.h,v 1.11 2001/07/02 13:59:15 markus Exp $     */
+/*      $OpenBSD: session.h,v 1.12 2001/10/09 21:59:41 markus Exp $     */
 
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
@@ -32,6 +32,6 @@ int	 session_open(Authctxt*, int);
 void     session_input_channel_req(int, void *);
 void     session_close_by_pid(pid_t, int);
 void     session_close_by_channel(int, void *);
-int      session_have_children(void);
+void     session_close_all(void);
 
 #endif