in.rexecd, rexecd - remote execution server
in.rexecd is the server for the rexec(3SOCKET)
routine. The server provides remote execution facilities with authentication
based on user names and passwords. It is invoked automatically as needed by
inetd(8), and then executes the following protocol:
- The server reads characters from the socket up to a null (\0) byte.
The resultant string is interpreted as an ASCII number, base
- If the number received in step 1 is non-zero, it is interpreted as the
port number of a secondary stream to be used for the stderr. A
second connection is then created to the specified port on the client's
- A null terminated user name of at most 16 characters is retrieved on the
- A null terminated password of at most 16 characters is retrieved on the
- A null terminated command to be passed to a shell is retrieved on the
initial socket. The length of the command is limited by the upper bound on
the size of the system's argument list.
- rexecd then validates the user as is done at login time and, if the
authentication was successful, changes to the user's home directory, and
establishes the user and group protections of the user. If any of these
steps fail the connection is aborted and a diagnostic message is
- A null byte is returned on the connection associated with the
stderr and the command line is passed to the normal login shell of
the user. The shell inherits the network connections established by
in.rexecd and rexecd are IPv6-enabled. See
All diagnostic messages are returned on the connection associated
with the stderr, after which any network connections are closed. An
error is indicated by a leading byte with a value of 1 (0 is returned in
step 7 above upon successful completion of all the steps prior to the
username too long
The name is longer than 16 characters.
password too long
The password is longer than 16 characters.
command too long
The command line passed exceeds the size of the argument
list (as configured into the system).
No password file entry for the user name existed.
The wrong password was supplied.
No remote directory.
The chdir command to the home directory
A fork by the server failed.
The user's login shell could not be started.
The in.rexecd service is managed by the service management
facility, smf(7), under the service identifier:
Administrative actions on this service, such as enabling,
disabling, or requesting restart, can be performed using svcadm(8).
Responsibility for initiating and restarting this service is delegated to
inetd(8). Use inetadm(8) to make configuration changes and to
view configuration information for this service. The service's status can be
queried using the svcs(1) command.