ipsvd - examples

TCP/IP services
UDP/IP services
ipsvd instructions

TCP/IP service examples

This run script provides an identd service on 0.0.0.0:113

 #!/bin/sh
 exec tcpsvd -l0 0 113 identd

This run script provides a smtpfront-qmail service on 192.168.2.1:25, with per-host instructions through the constant database ./peers.cdb.

 #!/bin/sh
 exec 2>&1
 MAXSMTPD="`cat /var/qmail/control/concurrencyincoming`"
 exec softlimit -m2000000 \
   env SMTPGREETING=smarden.org \
       MAILRULES=/etc/mailfront/smtp/mailrules \
   tcpsvd -vp -uqmaild -c"$MAXSMTPD" -x./peers.cdb 192.168.2.1 25 \
     smtpfront-qmail

This run script provides a bincimaps service on 10.0.0.14:993, with per-host concurrency limit, and with per-host instructions through the directory ./peers.

 #!/bin/sh
 exec 2>&1
 exec tcpsvd -vvp -c40 -C10 -l0 -i./peers 10.0.0.14 993 \
   bincimap-up --logtype=multilog --conf=/etc/bincimap/bincimap.conf --ssl -- \
     /usr/bin/checkpw /usr/sbin/bincimapd

This run script provides a qmail-smtpd service on 192.168.14.6:25, with per-host concurrency limit, and with per-host instructions through the directory ./peers.

 #!/bin/sh
 exec 2>&1
 exec softlimit -m2000000 \
  tcpsvd -vvh -i./peers -uqmaild \
    -c40 -C'10:421 per host concurrency limit reached\r\n' \
      192.168.14.6 25 qmail-smtpd

UDP/IP service examples

This run script provides a talkd service on 192.168.1.1:517

 #!/bin/sh
 exec udpsvd -unobody:tty 192.168.1.1 517 in.talkd

This run script provides a tftpd service on 0.0.0.0:69 with per-IP-address instructions through the directory /etc/tftpd/peers

 #!/bin/sh
 cd /
 exec 2>&1
 exec udpsvd -v -lbootserver -unobody -i/etc/tftpd/peers 0 69 \
   in.tftpd -s /boot/tftpboot/

ipsvd instruction examples

This run script provides a telnetd TCP/IP service, with per-IP-address instructions through the directory ./peers

 #!/bin/sh
 exec tcpsvd -i./peers 0.0.0.0 23 in.telnetd

Per default any client IP address is allowed to connect to this service. To allow connections from 192.168.1.17, and to deny connections from anywhere else, do

 # touch ./peers/192.168.1.17; chmod 644 ./peers/192.168.1.17
 # touch ./peers/0; chmod 0 ./peers/0

To allow connections from 192.168.3.0-255, do

 # touch ./peers/192.168.3; chmod 644 ./peers/192.168.3

To deny connections from 10.0.*.* explicitly, do

 # touch ./peers/10.0; chmod 0 ./peers/10.0

To have TRUST=true set in the environment when running in.telnetd for a connection from 192.168.14.2, do

 # echo '+TRUST=true' >./peers/192.168.14.2; chmod 644 ./peers/192.168.14.2

To provide a sshd login for connections from 10.2.0.14 on port 23, and the usual telnetd service for all others, do

 # echo 'sshd -i' >./peers/10.2.0.14; chmod 744 ./peers/10.2.0.14

To allow only connections from IP addresses the (dynamic) hostnames floyd.dyn.smarden.org and greg.dyn.smarden.org currently resolve to, do

 # echo '=floyd.dyn.smarden.org' >./peers/0
 # echo '=greg.dyn.smarden.org' >>./peers/0
 # chmod 644 ./peers/0

See ipsvd instructions for details.

Gerrit Pape <pape@smarden.org>