hang on exit

[Nicolas Williams]

Woa!

What's up with this? Why a server-side patch? I thought we'd all agreed
that this needs to be a client-side decision. After all, the client
knows when the session exits and can choose what to do.

I just posted a function which has code to force a channel closed. That
has to be possible in order to provide some of the hang-on-exit options
that have been discussed here. I used chan_read_failed() and
chan_write_failed() and channel_close_fds(). I see that you're using
chan_read_failed() here, so, can I conclude that that is the right
approach to forcing channel closures?

Nico


On Mon, Feb 04, 2002 at 08:32:26PM +0100, Markus Friedl wrote:
> untested, as i don't have access to a system that
> shows the hang-on-exit problem.
> 
> Index: servconf.c
> ===================================================================
> RCS file: /cvs/openssh_cvs/servconf.c,v
> retrieving revision 1.74
> diff -u -r1.74 servconf.c
> --- servconf.c	22 Jan 2002 12:35:12 -0000	1.74
> +++ servconf.c	4 Feb 2002 15:46:05 -0000
> @@ -91,6 +91,7 @@
>  	options->permit_empty_passwd = -1;
>  	options->use_login = -1;
>  	options->allow_tcp_forwarding = -1;
> +	options->allow_data_loss_on_pty = -1;
>  	options->num_allow_users = 0;
>  	options->num_deny_users = 0;
>  	options->num_allow_groups = 0;
> @@ -209,6 +210,8 @@
>  		options->use_login = 0;
>  	if (options->allow_tcp_forwarding == -1)
>  		options->allow_tcp_forwarding = 1;
> +	if (options->allow_data_loss_on_pty == -1)
> +		options->allow_data_loss_on_pty = 0;
>  	if (options->gateway_ports == -1)
>  		options->gateway_ports = 0;
>  	if (options->max_startups == -1)
> @@ -257,7 +260,7 @@
>  	sPrintMotd, sPrintLastLog, sIgnoreRhosts,
>  	sX11Forwarding, sX11DisplayOffset,
>  	sStrictModes, sEmptyPasswd, sKeepAlives,
> -	sUseLogin, sAllowTcpForwarding,
> +	sUseLogin, sAllowTcpForwarding, sAllowDataLossOnPty
>  	sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
>  	sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
>  	sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem, sMaxStartups,
> @@ -321,6 +324,7 @@
>  	{ "uselogin", sUseLogin },
>  	{ "keepalive", sKeepAlives },
>  	{ "allowtcpforwarding", sAllowTcpForwarding },
> +	{ "allowdatalossonpty", sAllowDataLossOnPty },
>  	{ "allowusers", sAllowUsers },
>  	{ "denyusers", sDenyUsers },
>  	{ "allowgroups", sAllowGroups },
> @@ -707,6 +711,10 @@
>  
>  	case sAllowTcpForwarding:
>  		intptr = &options->allow_tcp_forwarding;
> +		goto parse_flag;
> +
> +	case sAllowDataLossOnPty:
> +		intptr = &options->allow_data_loss_on_pty;
>  		goto parse_flag;
>  
>  	case sAllowUsers:
> Index: servconf.h
> ===================================================================
> RCS file: /cvs/openssh_cvs/servconf.h,v
> retrieving revision 1.42
> diff -u -r1.42 servconf.h
> --- servconf.h	21 Dec 2001 03:45:49 -0000	1.42
> +++ servconf.h	4 Feb 2002 15:46:05 -0000
> @@ -98,6 +98,7 @@
>  					 * passwords. */
>  	int     use_login;	/* If true, login(1) is used */
>  	int	allow_tcp_forwarding;
> +	int	allow_data_loss_on_pty;
>  	u_int num_allow_users;
>  	char   *allow_users[MAX_ALLOW_USERS];
>  	u_int num_deny_users;
> Index: serverloop.c
> ===================================================================
> RCS file: /cvs/openssh_cvs/serverloop.c,v
> retrieving revision 1.94
> diff -u -r1.94 serverloop.c
> --- serverloop.c	22 Jan 2002 12:29:23 -0000	1.94
> +++ serverloop.c	4 Feb 2002 15:46:06 -0000
> @@ -391,6 +391,11 @@
>  			buffer_append(&stderr_buffer, buf, len);
>  		}
>  	}
> +	if (child_terminated && options.allow_data_loss_on_pty == 1 &&
> +	    fderr == -1 && !fdout_eof) {
> +		close(fdout);
> +		fdout_eof = 1;
> +	}
>  }
>  
>  /*
> Index: session.c
> ===================================================================
> RCS file: /cvs/openssh_cvs/session.c,v
> retrieving revision 1.166
> diff -u -r1.166 session.c
> --- session.c	22 Jan 2002 12:16:34 -0000	1.166
> +++ session.c	4 Feb 2002 15:46:06 -0000
> @@ -1892,6 +1892,9 @@
>  	 */
>  	if (c->ostate != CHAN_OUTPUT_CLOSED)
>  		chan_write_failed(c);
> +	if (s->ttyfd != -1 && c->istate == CHAN_INPUT_OPEN &&
> +	    options.allow_data_loss_on_pty == 1)
> +		chan_read_failed(c);
>  	s->chanid = -1;
>  }
>  
> _______________________________________________
> openssh-unix-dev at mindrot.org mailing list
> http://www.mindrot.org/mailman/listinfo/openssh-unix-dev
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