When someone is behind a home router and needs help with linux, it is hard to get a shell on their computer, because, even if ssh is installed, it is not reachable from the Internet.

A solution is to have them copy and paste a command in the terminal (after having installed socat):

socat tcp4:[your_public_ip]:[reachable_port] tcp4:localhost:22

then on your machine, you do:

socat tcp4-listen:[reachable_port] tcp4-listen:2222

so that

ssh [user]@localhost -p 2222

should get you to the n00b’s ssh server.

I am currently working on a script to avoid ssh and use socat with screen and sudo to provide immediate and password-less root access.

Mi fanno morire dal ridere certi annunci di lavoro di alcune aziende sulla mailing list dell’Università, che cercano l’orso bruno albino, invece che l’orso polare.

Un esempio di una mail di questi giorni:

Professionalità principale	Professionalità opposta
Ambiente Windows	Ambiente Linux
Visual Studio, C#, .NET, VBScript	Bash, Python
Assistenza client Windows	Laurea in informatica
Capacità di lavoro autonomo	Contratto da dipendente a tempo determinato
Windows Server DHCP, DNS, Active Directory, File server	Conoscenza avanzata Linux: VPN, DNS, DHCP, FTP, firewall

(more…)

I have made a script to create a VPN on top of SSH. There’s plenty of those probably, but mine has a few optional features that probably no else has:

• Changes routing and name servers.
• Suspends the dhcp client. You can even leave NetworkManager on.
• Tries to bypass http proxies, using connect-proxy.
• Supports blocking all other traffic, making the client invisible on the local network.
• Tor support: single hop (through tortunnel) or three hops (normal tor) indirection.

The prerequisites are:

1. having ssh connectivity to a machine from the internet (server)
2. having root credentials for that machine
3. enabling root logins and tunnels in sshd on the said machine
4. enabling ip forwarding and probably masquerading (NAT) on the server
5. having root powers on the local client to run this script
6. optionals: connect-proxy, tortunnel (torproxy) , tor

(more…)

Anche quest’anno partecipo alle lezioni dagli studenti di informatica per gli studenti stessi e chi altro si voglia aggregare liberamente.

(more…)

There’s blogging nowadays and everyone has to be writing stuff on the web all the time about what they have been doing. Sometimes even to the cost of not actually doing it properly.
Payments from a big site, advertising, visibility or pure ego satisfaction are the reasons behind the proliferation of not-very-good information.

I try not to blog about anything I am not an expert on, but many people seem to be desperate about writing a post and having it linked to newsfeeds aggregators, to the point that they don’t care if they are publishing, well, bullshit.
In the free sofware community, but probably everywhere, this new trend is somewhat harmful, because people browse the web looking to fix problems or to learn about and improve their open source OS and they need to find sound technical information. (more…)