介绍
xinetd - the extended Internet services daemon xinetd performs the same function as inetd: it starts programs that provide Internet services. Instead of having such servers started at system initialization time, and be dormant until a connection request arrives, xinetd is the only daemon process started and it listens on all service ports for the services listed in its configuration file. When a request comes in, xinetd starts the appropriate server. Because of the way it operates, xinetd (as well as inetd) is also referred to as a super-server. <! – more –> The services listed in xinetd’s configuration file can be separated into two groups. Services in the first group are called multi-threaded and they require the forking of a new server process for each new con- nection request. The new server then handles that connection. For such services, xinetd keeps listening for new requests so that it can spawn new servers. On the other hand, the second group includes ser- vices for which the service daemon is responsible for handling all new connection requests. Such services are called single-threaded and xinetd will stop handling new requests for them until the server dies. Services in this group are usually datagram-based.
So far, the only reason for the existence of a super-server was to con- serve system resources by avoiding to fork a lot of processes which might be dormant for most of their lifetime. While fulfilling this function, xinetd takes advantage of the idea of a super-server to pro- vide features such as access control and logging. Furthermore, xinetd is not limited to services listed in /etc/services. Therefore, anybody
以下内容转载自 linuxfromscratch
- xinetd.conf文件
cat > /etc/xinetd.conf << "EOF"
# Begin /etc/xinetd
# Configuration file for xinetd
#
defaults
{
instances = 60
log_type = SYSLOG daemon
log_on_success = HOST PID USERID
log_on_failure = HOST USERID
cps = 25 30
}
# All service files are stored in the /etc/xinetd.d directory
#
includedir /etc/xinetd.d
# End /etc/xinetd
EOF
常见服务项配置
install -v -d -m755 /etc/xinetd.d &&
cat > /etc/xinetd.d/login << "EOF" &&
# Begin /etc/xinetd.d/login
service login
{
disable = yes
socket_type = stream
protocol = tcp
wait = no
user = root
server = /usr/sbin/in.rlogind
log_type = SYSLOG local4 info
}
# End /etc/xinetd.d/login
EOF
cat > /etc/xinetd.d/shell << "EOF" &&
# Begin /etc/xinetd.d/shell
service shell
{
disable = yes
socket_type = stream
wait = no
user = root
instances = UNLIMITED
flags = IDONLY
log_on_success += USERID
server = /usr/sbin/in.rshd
}
# End /etc/xinetd.d/shell
EOF
cat > /etc/xinetd.d/exec << "EOF" &&
# Begin /etc/xinetd.d/exec
service exec
{
disable = yes
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.rexecd
}
# End /etc/xinetd.d/exec
EOF
cat > /etc/xinetd.d/comsat << "EOF" &&
# Begin /etc/xinetd.d/comsat
service comsat
{
disable = yes
socket_type = dgram
wait = yes
user = nobody
group = tty
server = /usr/sbin/in.comsat
}
# End /etc/xinetd.d/comsat
EOF
cat > /etc/xinetd.d/talk << "EOF" &&
# Begin /etc/xinetd.d/talk
service talk
{
disable = yes
socket_type = dgram
wait = yes
user = root
server = /usr/sbin/in.talkd
}
# End /etc/xinetd.d/talk
EOF
cat > /etc/xinetd.d/ntalk << "EOF" &&
# Begin /etc/xinetd.d/ntalk
service ntalk
{
disable = yes
socket_type = dgram
wait = yes
user = root
server = /usr/sbin/in.ntalkd
}
# End /etc/xinetd.d/ntalk
EOF
cat > /etc/xinetd.d/telnet << "EOF" &&
# Begin /etc/xinetd.d/telnet
service telnet
{
disable = yes
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
bind = 127.0.0.1
log_on_failure += USERID
}
service telnet
{
disable = yes
socket_type = stream
wait = no
user = root
# server = /usr/sbin/in.telnetd
bind = 192.231.139.175
redirect = 128.138.202.20 23
log_on_failure += USERID
}
# End /etc/xinetd.d/telnet
EOF
cat > /etc/xinetd.d/ftp << "EOF" &&
# Begin /etc/xinetd.d/ftp
service ftp
{
disable = yes
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.ftpd
server_args = -l
instances = 4
log_on_success += DURATION USERID
log_on_failure += USERID
access_times = 2:00-8:59 12:00-23:59
nice = 10
}
# End /etc/xinetd.d/ftp
EOF
cat > /etc/xinetd.d/tftp << "EOF" &&
# Begin /etc/xinetd.d/tftp
service tftp
{
disable = yes
socket_type = dgram
wait = yes
user = root
server = /usr/sbin/in.tftpd
server_args = -s /tftpboot
}
# End /etc/xinetd.d/tftp
EOF
cat > /etc/xinetd.d/finger << "EOF" &&
# Begin /etc/xinetd.d/finger
service finger
{
disable = yes
socket_type = stream
wait = no
user = nobody
server = /usr/sbin/in.fingerd
}
# End /etc/xinetd.d/finger
EOF
cat > /etc/xinetd.d/systat << "EOF" &&
# Begin /etc/xinetd.d/systat
service systat
{
disable = yes
socket_type = stream
wait = no
user = nobody
server = /usr/bin/ps
server_args = -auwwx
only_from = 128.138.209.0
log_on_success = HOST
}
# End /etc/xinetd.d/systat
EOF
cat > /etc/xinetd.d/netstat << "EOF" &&
# Begin /etc/xinetd.d/netstat
service netstat
{
disable = yes
socket_type = stream
wait = no
user = nobody
server = /usr/ucb/netstat
server_args = -f inet
only_from = 128.138.209.0
log_on_success = HOST
}
# End /etc/xinetd.d/netstat
EOF
cat > /etc/xinetd.d/echo << "EOF" &&
# Begin /etc/xinetd.d/echo
service echo
{
disable = yes
type = INTERNAL
id = echo-stream
socket_type = stream
protocol = tcp
user = root
wait = no
}
service echo
{
disable = yes
type = INTERNAL
id = echo-dgram
socket_type = dgram
protocol = udp
user = root
wait = yes
}
# End /etc/xinetd.d/echo
EOF
cat > /etc/xinetd.d/chargen << "EOF" &&
# Begin /etc/xinetd.d/chargen
service chargen
{
disable = yes
type = INTERNAL
id = chargen-stream
socket_type = stream
protocol = tcp
user = root
wait = no
}
service chargen
{
disable = yes
type = INTERNAL
id = chargen-dgram
socket_type = dgram
protocol = udp
user = root
wait = yes
}
# End /etc/xinetd.d/chargen
EOF
cat > /etc/xinetd.d/daytime << "EOF" &&
# Begin /etc/xinetd.d/daytime
service daytime
{
disable = yes
type = INTERNAL
id = daytime-stream
socket_type = stream
protocol = tcp
user = root
wait = no
}
service daytime
{
disable = yes
type = INTERNAL
id = daytime-dgram
socket_type = dgram
protocol = udp
user = root
wait = yes
}
# End /etc/xinetd.d/daytime
EOF
cat > /etc/xinetd.d/time << "EOF" &&
# Begin /etc/xinetd.d/time
service time
{
disable = yes
type = INTERNAL
id = time-stream
socket_type = stream
protocol = tcp
user = root
wait = no
}
service time
{
disable = yes
type = INTERNAL
id = time-dgram
socket_type = dgram
protocol = udp
user = root
wait = yes
}
# End /etc/xinetd.d/time
EOF
cat > /etc/xinetd.d/rstatd << "EOF" &&
# Begin /etc/xinetd.d/rstatd
service rstatd
{
disable = yes
type = RPC
flags = INTERCEPT
rpc_version = 2-4
socket_type = dgram
protocol = udp
server = /usr/sbin/rpc.rstatd
wait = yes
user = root
}
# End /etc/xinetd.d/rstatd
EOF
cat > /etc/xinetd.d/rquotad << "EOF" &&
# Begin /etc/xinetd.d/rquotad
service rquotad
{
disable = yes
type = RPC
rpc_version = 1
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/rpc.rstatd
}
# End /etc/xinetd.d/rquotad
EOF
cat > /etc/xinetd.d/rusersd << "EOF" &&
# Begin /etc/xinetd.d/rusersd
service rusersd
{
disable = yes
type = RPC
rpc_version = 1-2
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/rpc.rusersd
}
# End /etc/xinetd.d/rusersd
EOF
cat > /etc/xinetd.d/sprayd << "EOF" &&
# Begin /etc/xinetd.d/sprayd
service sprayd
{
disable = yes
type = RPC
rpc_version = 1
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/rpc.sprayd
}
# End /etc/xinetd.d/sprayd
EOF
cat > /etc/xinetd.d/walld << "EOF" &&
# Begin /etc/xinetd.d/walld
service walld
{
disable = yes
type = RPC
rpc_version = 1
socket_type = dgram
protocol = udp
wait = yes
user = nobody
group = tty
server = /usr/sbin/rpc.rwalld
}
# End /etc/xinetd.d/walld
EOF
cat > /etc/xinetd.d/irc << "EOF"
# Begin /etc/xinetd.d/irc
service irc
{
disable = yes
socket_type = stream
wait = no
user = root
flags = SENSOR
type = INTERNAL
bind = 192.168.1.30
deny_time = 60
}
# End /etc/xinetd.d/irc
EOF
使用方式
若要激活服务，将配置文件中的disable = yes替换为disable = no
重新启动xinetd.service
权限问题
echo rsh >>/etc/securetty- 注释/etc/pam.d/目录下服务授权配置（待展开）