[SOLVED] Various tftp errors using get and put commands

JockVSJock · 02-12-2021, 10:39 AM

Using RHEL7 for tftp client, not able to put and get a basic text file via tftp. The tftp server is RHEL8 (we have self-support, so don't have the option to open a case).

I've disable SELinux and Firewalld on both server and client.

When using the get command, I'm able to download the text file, but its empty.

When I use the put command for a text file, I get a "client timed out" error.

I tail /var/log/messages and don't see anything odd.

systemd shows both a service and socket are active for tftp

Code:

[foo@foo xinetd.d]$ sudo systemctl status tftp.service
● tftp.service - Tftp Server
   Loaded: loaded (/usr/lib/systemd/system/tftp.service; linked; vendor preset: disabled)
   Active: active (running) since Fri 2021-02-12 11:16:31 EST; 6min ago
     Docs: man:in.tftpd
 Main PID: 8907 (in.tftpd)
    Tasks: 1 (limit: 45874)
   Memory: 320.0K
   CGroup: /system.slice/tftp.service
           └─8907 /usr/sbin/in.tftpd -c -p -s /var/lib/tftpboot

Feb 12 11:16:31 foo systemd[1]: Started Tftp Server.
[foo@foo xinetd.d]$ sudo systemctl status tftp.socket
● tftp.socket - Tftp Server Activation Socket
   Loaded: loaded (/usr/lib/systemd/system/tftp.socket; enabled; vendor preset: disabled)
   Active: active (running) since Fri 2021-02-12 11:16:15 EST; 7min ago
   Listen: [::]:69 (Datagram)
   CGroup: /system.slice/tftp.socket

Feb 12 11:16:15 foo systemd[1]: Stopping Tftp Server Activation Socket.
Feb 12 11:16:15 foo systemd[1]: Listening on Tftp Server Activation Socket.

Using ss command from tftp server, show that the port 69 is listening

Code:

foo@foo xinetd.d]$ ss -aul | grep :69
UNCONN   0         0                         *:69                      *:*

From the tftp client, I've turned the following on:

Code:

status
verbose
trace

tftp content lives under /var/lib/tftpboot, I'm wondering if /etc/systemd/system/tftp.service files is correct or not on the tftp server.

Code:

 1 [Unit]
  2 Description=Tftp Server
  3 Requires=tftp.socket
  4 Documentation=man:in.tftpd
  5 
  6 [Service]
  7 ExecStart=/usr/sbin/in.tftpd -c -p -s /var/lib/tftpboot
  8 StandardInput=socket
  9 
 10 [Install]
 11 Also=tftp.socket

teckk · 02-14-2021, 04:19 PM

There are howto's if the give you any info.
https://computingforgeeks.com/how-to...centos-rhel-8/
https://www.tecmint.com/install-ftp-server-in-rhel-8/
https://access.redhat.com/documentat..._guide/ch30s03
https://linuxconfig.org/how-to-insta...pd-on-redhat-8
https://italchemy.wordpress.com/2018...tos-7-5-linux/

JockVSJock · 02-14-2021, 07:38 PM

Thanks for the URLs.

Believe it or not, I used tecmint and compuatingforgeeks URLs for setup and troubleshooting.

Still having issues. I'm confused because Xinetd has a file under /etc/xinetd.d with settings for tftp, however systemd has a .socket and .service for both tftp. Not sure which one takes precedence.

Looks like I can setup logging via this Red Hat solutions (https://access.redhat.com/solutions/451773), however I didn't see anything going into /var/log/messages to begin with.

thanks

michaelk · 02-14-2021, 07:58 PM

Quote:

--create, -c
Allow new files to be created. By default, tftpd will only allow upload of files that already exist. Files are created with default permissions allowing anyone to read or write them, unless the --permissive or --umask options are specified.

--user username, -u username
Specify the username which tftpd will run as; the default is "nobody". The user ID, group ID, and (if possible on the platform) the supplementary group IDs will be set to the ones specified in the system permission database for this username.

--permissive, -p
Perform no additional permissions checks above the normal system-provided access controls for the user specified via the --user option.

I believe it is a permission issue. If I understand the above because your using -p means any file not owned by nobody read/write is not allowed and therefore not transferred.
Try removing the -p option.

https://linux.die.net/man/8/tftpd

JockVSJock · 02-15-2021, 07:48 AM

So I did the following, I remove the -p under /etc/systemd/system/tftp.service, so it now looks like this:

Code:

[Service]
ExecStart=/usr/sbin/in.tftpd -c -s /var/lib/tftpboot
StandardInput=socket

Once doing that reloaded all daemons with the following command:

Code:

systemctl daemon-reload

I fired up the tftp client,

Code:

tftp xx.xx.xx.xx
verbose
trace
get test_file1.txt

Was able to download the test .txt file and it was successful.

thanks