NAME [Toc] [Back]
inetd.sec - optional security file for inetd
DESCRIPTION [Toc] [Back]
When inetd accepts a connection from a remote system, it checks the
address of the host requesting the service against the list of hosts
to be allowed or denied access to the specific service (see
inetd(1M)). The file inetd.sec allows the system administrator to
control which hosts (or networks in general) are allowed to use the
system remotely. This file constitutes an extra layer of security in
addition to the normal checks done by the services. It precedes the
security of the servers; that is, a server is not started by the
Internet daemon unless the host requesting the service is a valid host
according to inetd.sec.
If file /var/adm/inetd.sec does not exist, security is limited to that
implemented by the servers. inetd.sec and the directory /var/adm
should be writable only by their owners. Changes to inetd.sec apply
to any subsequent connections.
Lines in inetd.sec beginning with # are comments. Comments are not
allowed at the end of a line of data.
The lines in the file contain a service name, permission field, and
the Internet addresses or official names of the hosts and networks
allowed to use that service in the local host. The fields in each
line are as follows:
<service name> <allow|deny> <host/net addresses, host/net names>
service name is the name (not alias) of a valid service in file
/etc/services. The service name for RPC-based services (NFS) is the
name (not alias) of a valid service in file /etc/rpc. A service name
in /etc/rpc corresponds to a unique RPC program number.
allow|deny determines whether the list of remote hosts in the next
field is allowed or denied access to the specified service. Multiple
allow|deny lines for each service are not unsupported. If there are
multiple allow|deny lines for a particular service, all but the last
line are ignored.
Addresses and names are separated by white space. Any mix of
addresses and names is allowed. To continue a line, terminate it with
Host names and network names are the official names of the hosts or
networks as returned by gethostbyaddr() or getnetbyaddr(),
respectively. Wildcard characters (*) and range characters (-) are
allowed. The * and the - can be present in any of the fields of the
address. An address field is a string of characters separated by a
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003
EXAMPLES [Toc] [Back]
Use a wildcard character to permit a whole network to communicate with
the local host without having to list all the hosts in that network.
For example, to allow all hosts with network addresses starting with a
10, as well as the single host with address 18.104.22.168 to use rlogin:
login allow 10.* 22.214.171.124
On a system running NFS, deny host 126.96.36.199 access to sprayd, an
sprayd deny 188.8.131.52
A range is a field containing a - character. To deny hosts in network
10 (arpa) with subnets 3 through 5 access to remsh:
shell deny 10.3-5.*
The following entry denies rlogin access to host cory.berkeley.edu,
any hosts on the network named testlan, and the host with internet
login deny 184.108.40.206 cory.berkeley.edu testlan
If a remote service is not listed in the security file, or if it is
listed but it is not followed by allow or deny, all remote hosts can
attempt to use it. Security is then provided by the service itself.
The following lines, if present in inetd.sec, allow or deny access to
the service indicated:
Allow all hosts to use ftp:
Deny all access to the shell service; i.e., remsh:
Allow access to the shell service by any host:
IPv6 FUNCTIONALITY [Toc] [Back]
For an IPv6 service, an IPv6 address can be specified in the host
address field of inetd.sec. The host address field can contain IPv6
addresses, IPv4 addresses, or both. This specification includes the
IPv4 mapped IPv6 addresses also.
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Host names for IPv6 services are the official names of the hosts
returned by getaddrinfo().
The wildcard characters (*) and range characters (-) are not supported
for IPv6 addresses. The equivalent for the wildcard character (*) is
provided in the form of subnet_prefix followed by a forward-slash (/)
and prefix_length. See the IPv6 Examples section for more details.
IPv6 EXAMPLES [Toc] [Back]
To allow an IPv6 host with address fe80::210:83ff:feb9:903f and an
IPv4 host with address 220.127.116.11 in order to use the telnet service,
an entry in the inetd.sec file should be as follows :
telnet allow fe80::210:83ff:feb9:903f 18.104.22.168
The following entry denies ftp access to all hosts with a prefix fe80:
ftp deny fe80::/16
WARNINGS [Toc] [Back]
IPv6 is supported on HP-UX 11i Version 1.0, with the optional IPv6
software installed. Currently, IPv6 is not supported on systems
running HP-UX 11i Version 1.6.
AUTHOR [Toc] [Back]
inetd.sec was developed by HP.
NFS was developed by Sun Microsystems, Inc.
FILES [Toc] [Back]
SEE ALSO [Toc] [Back]
inetd(1M), gethostent(3N), getaddrinfo(3N), getnetent(3N), hosts(4),
inetd.conf(4), networks(4), protocols(4), rpc(4), services(4).
Hewlett-Packard Company - 3 - HP-UX 11i Version 2: August 2003 [ Back ]