Two patches for OpenSSH 3.1p1 (fwd)
Ben Lindstrom
mouring at etoh.eviladmin.org
Sat Mar 30 07:09:57 EST 2002
3.1p1, but the main part is in serverloop.c which should apply to any
decently recent release.
- Ben
On 29 Mar 2002, Austin Gonyou wrote:
> I will try the patch later today. What version does this apply to?
>
> On Fri, 2002-03-29 at 12:26, Ben Lindstrom wrote:
> >
> >
> > Can I get people from other platforms to test the waitpid.patch to see
> > if it solves hang-on-exit on their platform?
> >
> > I can confirm Solaris at this moment (but I've not done heavy testing at
> > this moment) that is works like a charm (Solaris 7). It handles 'sleep
> > 90&' vs 'nohup sleep 90&' correctly (killed, vs left).
> >
> > thanks.
> >
> > - Ben
> >
> > ---------- Forwarded message ----------
> > Date: Tue, 26 Mar 2002 22:21:31 +0100 (MET)
> > From: Peter Eriksson <peter at ifm.liu.se>
> > To: openssh-unix-dev at mindrot.org
> > Subject: Two patches for OpenSSH 3.1p1
> >
> > Please find enclosed two patches for OpenSSH 3.1p1.
> >
> > The first patch solves a problem where sessions will be left "hanging"
> > when you normally exit from a ssh shell (for example by logging out from
> > the remote host via "exit" or "logout"). The problem seems to be that
> > sshd
> > (and some other parts of OpenSSH) doesn't check the return code and
> > errno
> > from waitpid() for errno == EINTR and thus fails to collect the started
> > subprocess correctly. This problem occurs atleast on Solaris 2 and
> > UNICOS
> > systems but it should probably exist on all other SysV based systems...
> > (It doesn't occur all the time so it can be quite hard to test for).
> >
> > The other patch adds a "-I" command line option to allow sshd to be
> > correctly started (and automatically restarted) by "init" (via the
> > /etc/inittab file) on systems with a SysV-style "init".
> >
> > It is *not* sufficent to just use the "-D" (no daemon) flag since that
> > doesn't correctly handle log file output, closing of stdin/stdout/stderr
> > or the setsid() call to drop the controlling TTY.
> >
> > Trying to start sshd via inittab and using "-D" will cause sshd to
> > terminate if the Console connection (for example if using a serial
> > terminal) gets dropped...
> >
> > --
> > Peter Eriksson <peter at ifm.liu.se> Phone: +46 13 28 2786
> > Computer Systems Manager/BOFH Cell/GSM: +46 705 18 2786
> > Physics Department, Linköping University Room: Building F, F203
> > SE-581 83 Linköping, Sweden
> > http://www.ifm.liu.se/~peter
> >
> > ----
> >
>
> > diff -r -c openssh-3.1p1/entropy.c openssh-3.1p1-peter/entropy.c
> > *** openssh-3.1p1/entropy.c Tue Jan 22 11:57:54 2002
> > --- openssh-3.1p1-peter/entropy.c Mon Mar 18 22:00:10 2002
> > ***************
> > *** 110,118 ****
> >
> > close(p[0]);
> >
> > ! if (waitpid(pid, &ret, 0) == -1)
> > ! fatal("Couldn't wait for ssh-rand-helper completion: %s",
> > strerror(errno));
> >
> > /* We don't mind if the child exits upon a SIGPIPE */
> > if (!WIFEXITED(ret) &&
> > --- 110,124 ----
> >
> > close(p[0]);
> >
> > ! {
> > ! int code;
> > !
> > ! while ((code = waitpid(pid, &ret, 0)) == -1 && errno == EINTR)
> > ! ;
> > ! if (code < 0)
> > ! fatal("Couldn't wait for ssh-rand-helper completion: %s",
> > strerror(errno));
> > + }
> >
> > /* We don't mind if the child exits upon a SIGPIPE */
> > if (!WIFEXITED(ret) &&
> > Only in openssh-3.1p1/scard: Ssh.bin
> > diff -r -c openssh-3.1p1/serverloop.c openssh-3.1p1-peter/serverloop.c
> > *** openssh-3.1p1/serverloop.c Fri Feb 8 12:07:17 2002
> > --- openssh-3.1p1-peter/serverloop.c Mon Mar 18 22:01:02 2002
> > ***************
> > *** 673,679 ****
> > /* We no longer want our SIGCHLD handler to be called. */
> > mysignal(SIGCHLD, SIG_DFL);
> >
> > ! wait_pid = waitpid(-1, &wait_status, 0);
> > if (wait_pid == -1)
> > packet_disconnect("wait: %.100s", strerror(errno));
> > else if (wait_pid != pid)
> > --- 673,681 ----
> > /* We no longer want our SIGCHLD handler to be called. */
> > mysignal(SIGCHLD, SIG_DFL);
> >
> > ! while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0 && errno == EINTR)
> > ! ;
> > !
> > if (wait_pid == -1)
> > packet_disconnect("wait: %.100s", strerror(errno));
> > else if (wait_pid != pid)
> > diff -r -c openssh-3.1p1/sftp-int.c openssh-3.1p1-peter/sftp-int.c
> > *** openssh-3.1p1/sftp-int.c Wed Feb 13 04:10:33 2002
> > --- openssh-3.1p1-peter/sftp-int.c Mon Mar 18 22:02:38 2002
> > ***************
> > *** 176,183 ****
> > strerror(errno));
> > _exit(1);
> > }
> > ! if (waitpid(pid, &status, 0) == -1)
> > fatal("Couldn't wait for child: %s", strerror(errno));
> > if (!WIFEXITED(status))
> > error("Shell exited abormally");
> > else if (WEXITSTATUS(status))
> > --- 176,192 ----
> > strerror(errno));
> > _exit(1);
> > }
> > ! {
> > ! int code;
> > !
> > !
> > ! while ((code = waitpid(pid, &status, 0)) == -1 && errno == EINTR)
> > ! ;
> > !
> > ! if (code < 0)
> > fatal("Couldn't wait for child: %s", strerror(errno));
> > + }
> > +
> > if (!WIFEXITED(status))
> > error("Shell exited abormally");
> > else if (WEXITSTATUS(status))
> > diff -r -c openssh-3.1p1/sftp.c openssh-3.1p1-peter/sftp.c
> > *** openssh-3.1p1/sftp.c Wed Feb 13 04:03:57 2002
> > --- openssh-3.1p1-peter/sftp.c Mon Mar 18 22:01:49 2002
> > ***************
> > *** 246,253 ****
> > if (infile != stdin)
> > fclose(infile);
> >
> > ! if (waitpid(sshpid, NULL, 0) == -1)
> > fatal("Couldn't wait for ssh process: %s", strerror(errno));
> >
> > exit(0);
> > }
> > --- 246,261 ----
> > if (infile != stdin)
> > fclose(infile);
> >
> > ! {
> > ! int code;
> > !
> > !
> > ! while ((code = waitpid(sshpid, NULL, 0)) == -1 && errno == EINTR)
> > ! ;
> > !
> > ! if (code < 0)
> > fatal("Couldn't wait for ssh process: %s", strerror(errno));
> > + }
> >
> > exit(0);
> > }
> > diff -r -c openssh-3.1p1/ssh-rand-helper.c openssh-3.1p1-peter/ssh-rand-helper.c
> > *** openssh-3.1p1/ssh-rand-helper.c Sun Feb 10 08:32:30 2002
> > --- openssh-3.1p1-peter/ssh-rand-helper.c Mon Mar 18 22:04:34 2002
> > ***************
> > *** 389,398 ****
> >
> > debug3("Time elapsed: %d msec", msec_elapsed);
> >
> > ! if (waitpid(pid, &status, 0) == -1) {
> > error("Couldn't wait for child '%s' completion: %s",
> > src->cmdstring, strerror(errno));
> > return 0.0;
> > }
> >
> > RAND_add(&status, sizeof(&status), 0.0);
> > --- 389,406 ----
> >
> > debug3("Time elapsed: %d msec", msec_elapsed);
> >
> > ! {
> > ! int code;
> > !
> > ! while ((code = waitpid(pid, &status, 0)) == -1 && errno == EINTR)
> > ! ;
> > !
> > ! if (code < 0)
> > ! {
> > error("Couldn't wait for child '%s' completion: %s",
> > src->cmdstring, strerror(errno));
> > return 0.0;
> > + }
> > }
> >
> > RAND_add(&status, sizeof(&status), 0.0);
> > diff -r -c openssh-3.1p1/sshd.c openssh-3.1p1-peter/sshd.c
> > *** openssh-3.1p1/sshd.c Tue Mar 5 02:31:30 2002
> > --- openssh-3.1p1-peter/sshd.c Mon Mar 18 22:03:37 2002
> > ***************
> > *** 264,273 ****
> > main_sigchld_handler(int sig)
> > {
> > int save_errno = errno;
> > ! int status;
> >
> > ! while (waitpid(-1, &status, WNOHANG) > 0)
> > ! ;
> >
> > signal(SIGCHLD, main_sigchld_handler);
> > errno = save_errno;
> > --- 264,274 ----
> > main_sigchld_handler(int sig)
> > {
> > int save_errno = errno;
> > ! int status, code;
> >
> > !
> > ! while ((code = waitpid(-1, &status, WNOHANG)) < 0 && errno == EINTR || code > 0)
> > ! ;
> >
> > signal(SIGCHLD, main_sigchld_handler);
> > errno = save_errno;
> --
> Austin Gonyou
> Systems Architect, CCNA
> Coremetrics, Inc.
> Phone: 512-698-7250
> email: austin at coremetrics.com
>
> "It is the part of a good shepherd to shear his flock, not to skin it."
> Latin Proverb
>
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