rexecd(8c) — AIX PS/2 1.2.1



REXECD(8c,C)                AIX TCP/IP User's Guide                REXECD(8c,C)



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rexecd



PURPOSE

Provides the server function for the rexec command.

SYNTAX


/etc/rexecd ---|


DESCRIPTION

The rexecd command is the server for the rexec routine.  The server provides
remote execution facilities with authentication based on user names and
passwords.

The rexecd command listens for service requests at the port indicated in the
service specification; see "services." When a service request is received the
following protocol is initiated:

  1. The server reads characters from the socket up to a null (0) byte.  The
    resultant string is interpreted as an ASCII number, base 10.

  2. 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 machine.

  3. A null terminated user name of at most 16 characters is retrieved on the
    initial socket.

  4. A null terminated, unencrypted password of at most 16 characters is
    retrieved on the initial socket.

  5. 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.

  6. The rexecd command then validates the user, as is done at login time and,
    if the verification is 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 broken with a diagnostic message
    returned.

  7. A null byte is returned on the initial socket and the command line is
    passed to the normal login shell of the user.  The shell inherits the
    network connections established by the rexecd command.




Processed October 29, 1990       REXECD(8c,C)                                 1



REXECD(8c,C)                AIX TCP/IP User's Guide                REXECD(8c,C)



Note:  The verification procedure used assumes the integrity of each client
machine and the connecting medium.  This is insecure, but is useful in an open
environment.

MESSAGES

All diagnostic messages are returned on the initial socket, 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 command execution).


username too long

Explanation:  The name is longer than 16 characters.

password too long

Explanation:  The password is longer than 16 characters.

command too long

Explanation:  The command line passed exceeds the size of the argument list (as
configured into the system).

Login incorrect

Explanation:  No password file entry for the user name existed.

Password incorrect

Explanation:  The wrong password was supplied.

No remote directory

Explanation:  The chdir command to the home directory failed.

Try again

Explanation:  A fork by the server failed.

RELATED INFORMATION

In this book:
"rexec"
"services"









Processed October 29, 1990       REXECD(8c,C)                                 2

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