The JNT Mail channel is structured and invoked in the manner
described in
channels(7).
The channel generates files of the format specified in the JNT Mail
Protocol. Copies of the JNT Mail Protocol can be obtained from
the Joint Network Team, c/o Rutherford Appleton Labs., Chilton,
Oxon, UK.
JNT Mail Files are created in the directory specified by the
variable
char *pn_quedir
which is tailored by the parameter NIQUEDIR (see the MMDF installation guide).
If #define VIATRACE is set, the message header in the JNT
Mail File will be modified to ensure that a correct receiving
implementation will determine a return path corresponding to
that passed to the channel.
When the file has been created, a file transfer process is called. Whilst this could in principle be any File Transfer Protocol, it is expected that in general the NIFTP (blue book) protocol will be used. The calling (execl) sequence is specified by the channel tailor parameter confstr. If the string contains a sequence $(parm) where parm is one of the strings listed, the value appropriate to the file will be inserted:
file - The full path of the JNT Mail File
host - The host (LHS of channel table)
adr - The address (RHS of channel table)
sender - Error return address
Examples:
For the York NIFTP:
MCHN janet name=janet,que=janet,tbl=janet,
show="via Janet with NIFTP",
pgm=niftp,poll=0,mod=reg,ap=jnt,
confstr="/usr/lib/x25/mhhcp mhhcp $(FILE) $(ADR)"
For the UCL/UKC NIFTP:
MCHN janet name=janet,que=janet,tbl=janet,
show="via Janet with NIFTP",
pgm=niftp,poll=0,mod=reg,ap=jnt,
confstr="/usr/bin/cpf cpf -t -f\"$(SENDER)\" $(FILE) @$(ADR)"
The channel interprets the FILE Transfer Protocol exit values according to the values defined in h/jnt.h:
#define JNT_OK 0 (Successful)
#define JNT_TEMP 1 (Temporary failure
- MMDF will retry)
(This is the default)
#define JNT_PERM 75 (Permanent failure
- MMDF will send
an error message
to the sender)
If JNT_OK is returned, the File Transfer Protocol is expected
to unlink the JNT Mail File, to allow for spooled or
non-spooled operation. In other cases, the channel will unlink the
file.
The JNT Mail channel runs setuid to daemon. If it is used with a File Transfer Protocol which expects a different uid, both this uid and the ownership of the JNT Mail spool directory should be changed accordingly.
<mmdflib>/chans/niftp
/usr/spool/jntmail.ni.???????
<mmdfsource>/h/jnt.h