标签：nginx ddos 攻击
FreeBSD, network card: Intel fxp, port: 100Мбит, polling, http accept-filter.
in sysctl:
sysctl kern.maxfiles=90000
sysctl kern.maxfilesperproc=80000
sysctl net.inet.tcp.blackhole=2
sysctl net.inet.udp.blackhole=1
sysctl kern.polling.burst_max=1000
sysctl kern.polling.each_burst=50
sysctl kern.ipc.somaxconn=32768
sysctl net.inet.tcp.msl=3000
sysctl net.inet.tcp.maxtcptw=40960
sysctl net.inet.tcp.nolocaltimewait=1
sysctl net.inet.ip.portrange.first=1024
sysctl net.inet.ip.portrange.last=65535
sysctl net.inet.ip.portrange.randomized=0
in nginx configuration:
worker_processes 1;
worker_rlimit_nofile 80000;
events {
worker_connections 50000;
}
server_tokens off;
log_format IP `$remote_addr';
reset_timedout_connection on;
listen xx.xx.xx.xx:80 default rcvbuf=8192 sndbuf=16384 backlog=32000 accept_filter=httpready;
In the following way it is possible to realize filtration of url, in example for POST
index.php?action=login which is with empty referral.
set $add 1;
location /index.php {
limit_except GET POST {
deny all;
}
set $ban "";
if ($http_referer = "" ) {set $ban $ban$add;}
if ($request_method = POST ) {set $ban $ban$add;}
if ($query_string = "action=login" ){set $ban $ban$add;}
if ($ban = 111 ) {
access_log /var/log/[133]nginx/ban IP;
return 404;
}
proxy_pass http://127.0.0.1:8000; #here is a patch
}
Further we cut it at pf level – loaded into IP table, hosts from which came too many hits.
PF with tables works very quickly. Sources for parsing of logs (ddetect) you can find on http://www.comsys.com.ua/files
Then Cron used once in a minute, to add into ip tables new IPs from a log.
25 Mbyte DDoS, which cuts IPs, the rests fall on nginx which by it is criterion pass IPs and the rests passed on the apache – LA 0, site works.