ks@pur-ee.UUCP (Smith) (12/15/84)
Description: Often, rlogin daemons terminate abnormally and fail to reset the modes on the psuedo tty. The next rlogin daemon can fix this since it runs as root, but script runs as the individual user and has no recourse. When script can't open the tty, it merely says "Permission denied" and exits. It should just skip over that pty and try the next... Repeat-By: % chmod 622 /dev/ttyp0 - or - % kill -9 rlogindpid % script Permission denied Fix: Just don't use a tty that you can't read and write: RCS file: RCS/script.c,v retrieving revision 1.1 retrieving revision 1.3 diff -c -r1.1 -r1.3 *** /tmp/,RCSt1007377 Fri Dec 14 21:10:58 1984 --- /tmp/,RCSt2007377 Fri Dec 14 21:11:02 1984 *************** *** 12,17 #include <sys/ioctl.h> #include <sgtty.h> #include <sys/time.h> char *getenv(); char *ctime(); --- 12,18 ----- #include <sys/ioctl.h> #include <sgtty.h> #include <sys/time.h> + #include <sys/file.h> char *getenv(); char *ctime(); *************** *** 191,196 line[strlen("/dev/ptyp")] = "0123456789abcdef"[i]; master = open(line, 2); if (master >= 0) { ioctl(0, TIOCGETP, (char *)&b); ioctl(0, TIOCGETC, (char *)&tc); ioctl(0, TIOCGETD, (char *)&l); --- 192,201 ----- line[strlen("/dev/ptyp")] = "0123456789abcdef"[i]; master = open(line, 2); if (master >= 0) { + if (!checkslave()) { + close(master); + continue; + } ioctl(0, TIOCGETP, (char *)&b); ioctl(0, TIOCGETC, (char *)&tc); ioctl(0, TIOCGETD, (char *)&l); *************** *** 202,207 } fprintf(stderr, "Out of pty's\n"); fail(); } getslave() --- 207,223 ----- } fprintf(stderr, "Out of pty's\n"); fail(); + } + + checkslave() + { + line[strlen("/dev/")] = 't'; + if (access(line, R_OK|W_OK) < 0) { + line[strlen("/dev/")] = 'p'; + return 0; + } + line[strlen("/dev/")] = 'p'; + return 1; } getslave()
dave@garfield.UUCP (David Janes) (12/18/84)
Also, it helps to add these lines to rc.local: chown root /dev/tty[pqr]* chmod 666 /dev/tty[pqr]* A common reason for rlogind being terminated abnormally is system crashes. dave (the Mercenary Programmer) ------- David Janes (Dept. of Redundancy Dept.) Internet: dave@garfield.UUCP UUCP: {allegra,ihnp4,utcsrgv}!garfield!dave