Attachment 730431 Details for Bug 947213 – Patch to make rlogind work again by keeping slave file descriptor open

[patch] Patch to make rlogind work again by keeping slave file descriptor open

netkit-rsh-0.17-vhangup.patch (text/plain), 1.74 KB, created by Philip Spencer on 2013-04-01 20:18:45 UTC

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Creator: Philip Spencer

Created: 2013-04-01 20:18:45 UTC

Size: 1.74 KB

patch

obsolete

>--- netkit-rsh-0.17/rlogind/rlogind.c.vhangup	2013-04-01 14:07:28.631790857 -0400
>+++ netkit-rsh-0.17/rlogind/rlogind.c	2013-04-01 14:09:17.300050652 -0400
>@@ -72,7 +72,8 @@
> #include "logwtmp.h"
> #include "rlogind.h"
> 
>-pid_t forkpty(int *, char *, struct termios *, struct winsize *);
>+#include <pty.h>
>+#include <utmp.h>
> int logout(const char *);
> 
> #ifndef TIOCPKT_WINDOW
>@@ -421,12 +422,33 @@
> 	write(netfd, "rlogind: Host address mismatch.\r\n", 33);
>     }
> 
>-    pid = forkpty(&master, line, NULL, &win);
>-    if (pid < 0) {
>+/*  We can no longer call forkpty here (a convenience routine that combines
>+    openpty, fork, and login_tty) because, with forkpty, the slave end of
>+    the pty is open only in the child process. The child process execs
>+    /bin/login which now closes all open file descriptors before doing a
>+    vhangup (see lkml.org/lkml/2012/6/5/145), and this resets packet mode
>+    on the pty, undoing the effect of the ioctl(master, TIOCPKT, &on) call
>+    made by the parent.
>+
>+    Instead, we call openpty, fork, and login_tty individually, so that we
>+    can keep a file descriptor to the slave open in the parent process,
>+    thereby retaining packet mode even when the child closes file descriptors
>+    to call vhangup. */
>+
>+    int slave;
>+    int err = openpty(&master, &slave, line, NULL, &win);
>+    if (err) {
> 	if (errno == ENOENT) fatal(netfd, "Out of ptys", 0);
>-	fatal(netfd, "Forkpty", 1);
>+	fatal(netfd, "Openpty", 1);
>+    }
>+    signal(SIGHUP, SIG_IGN);
>+    pid = fork();
>+    if (pid < 0) {
>+	fatal(netfd, "Fork", 1);
>     }
>     if (pid == 0) {
>+	close(master);
>+  	login_tty(slave);
> 	/* netfd should always be 0, but... */ 
> 	if (netfd > 2) close(netfd);
> 	child(hname, termtype, lusername, authenticated, rusername);

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Attachments on bug 947213: 730431