> On 01/25/2016 06:55 AM, Jeffrey Ross wrote: >> I'm in the process of setting up an SSH jail, for the most part its >> working as expected with one exception, I want to provide access to >> /dev/ttyUSB0 through /dev/ttyUSB4 (not 2) via cu. >> >> When I attempt to use "cu -lttyUSB0 -s9600" I always get "line in use" >> even through it is not in use and from another account not restricted to >> the "jail" I can successfully connect to the ttyUSB0. >> >> I've tried creating $chroot/ >> >> run/ >> lock/ >> lockdev/ >> uucp/ >> var/ >> run -> symbolic link to $chroot/run >> lock -> symbolic link to $chroot/run/lock >> >> and then matched the directory permissions so they are the same as the >> "real" system. >> >> ls -l $chroot/dev/ttyUSB? >> crwxrwxrwx 1 root dialout 188, 0 Jan 24 14:48 ttyUSB0 >> crwxrwxrwx 1 root dialout 188, 1 Jan 24 14:49 ttyUSB1 >> crwxrwxrwx 1 root dialout 188, 3 Jan 24 14:49 ttyUSB3 >> crwxrwxrwx 1 root dialout 188, 4 Jan 24 14:49 ttyUSB4 >> >> The dialout group is 18 and the user is in group 18, initially I set the >> permissions for the ttyUSB? to 660 before changing it to 777 as a last >> ditch effort. >> >> The "real" /dev/ttyUSB? - >> >> ls -l /dev/ttyUSB? >> crw-rw---- 1 root dialout 188, 0 Jan 24 14:44 /dev/ttyUSB0 >> crw-rw---- 1 root dialout 188, 1 Jan 23 21:48 /dev/ttyUSB1 >> crw-rw---- 1 root dialout 188, 3 Jan 24 15:12 /dev/ttyUSB3 >> crw-rw---- 1 root dialout 188, 4 Jan 23 21:48 /dev/ttyUSB4 >> >> I'm probably missing something simple and any suggestions would be >> appreciated. > > Uhm, double check the permissions on the $chroot/var/run and > $chroot/var/lock directories and make sure that the user you're trying > to run as has write permissions in those directories. It's been a > while, but IIRC the only way cu can determine if a device is in use is > by checking the lock files and if it can't create a lock file, it says > the device is in use. > > Why in the devil would you pull out that ancient program anyway? Man! > I haven't even LOOKED at cu/uucp in 15 years at least! Just in case the permissions were wrong I did a chmod -R 777 on the run directory, no dice, so I did the next best thing, I ran "strace -ff -o outfile cu -l...." found a few libraries I missed, not sure if that was part of the issue as that's not where the failure occurred. I did find that it forked (?) lockdev which is a program that I had not included $chroot, so I brought that program over into $chroot/usr/sbin/lockdev set the permission appropriately and everything began working. Why did I choose "cu" I know uucp is ancient but for a quick and dirty way to connect to various serial interfaces cu seems to work well, and although the remainder of the uucp suite comes with cu I did not configure uucp :) If you've got a suggestion for another program to use that will allow quick connectivity to various serial ports I'm all ears. Thanks! Jeff -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
