“born to program in C”

...
The fact is, that is *exactly* the kinds of things that C excels at. Not
just as a language, but as a required *mentality*. One of the great
strengths of C is that it doesn't make you think of your program as
anything high-level. It's what makes you apparently prefer other
languages, but the thing is, from a git standpoint, "high level" is
exactly the wrong thing.

                 Linus

lighttpd

Task management made simple with todo.txt and Tux ToDo

Artigo sobre ferramentas para gerenciamento de todo’s em modo texto e modo gráfico.

http://www.linux.com/articles/57473

Site do todo.txt:
http://todotxt.com

owl

Algum tempo atrás tinha visto um link com livros na lista do freebsd:
https://feradsl.cjb.net/owl-0.90/browse.php

Achei interessante a interface.
Mais além, nas aulas de comunicação de dados corporativa das
sextas-feiras, entramos no tema de web 2.0, web semântica, xml, owl,
rdf… nisso lembrei do link, e achei a página do Owl

http://owl.sourceforge.net/

What is Owl?
Owl is a multi user document repository (knowledgebase) system written
in PHP4 for publishing files/documents onto the web for a corporation,
small business, group of people, or just for yourself.

bloqueando brute force no ssh com ipt_recent

O módulo recent do iptables é muito útil e prático para bloquear tentativas de acesso ao ssh via brute force. Um exemplo de uso:

$IPTABLES -N recent_drop_log
$IPTABLES -A recent_drop_log -j LOG --log-prefix "recent_drop_log "
$IPTABLES -A recent_drop_log -j DROP

# ssh
$IPTABLES -A INPUT -i $EXTIF -p tcp --dport 22  --syn \
        -j LOG --log-prefix "ssh "
$IPTABLES -A INPUT -i $EXTIF -p tcp --dport 22  --syn  \
        -m recent --update --seconds 40 --hitcount 4 --name SSH --rsource \
        -j recent_drop_log
$IPTABLES -A INPUT -i $EXTIF -p tcp --dport 22  --syn  \
        -m recent --set --name SSH --rsource -j ACCEPT

No exemplo, ao ocorrer 4 aberturas de conexão ao ssh em até 40 segundos faz com que demais tentativas sejam “dropadas” automaticamente, até que se passe uma janela do mesmo tempo sem tentativas de conexão.

mtr

DESCRIPTION
mtr combines the functionality of the traceroute and ping programs in a
single network diagnostic tool.

As mtr starts, it investigates the network connection between the host
mtr runs on and HOSTNAME. by sending packets with purposly low TTLs.
It continues to send packets with low TTL, noting the response time of
the intervening routers. This allows mtr to print the response per-
centage and response times of the internet route to HOSTNAME. A sudden
increase in packetloss or response time is often an indication of a bad
(or simply overloaded) link.