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Trailing-Edge - PDP-10 Archives - bb-ev83b-bm_longer - tcpip-sources/maiser.mac
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	TITLE MAISER TOPS-20 SMTP mail server
	SUBTTL Written by Mark Crispin - November 1982

; Copyright (C) 1982, 1983, 1984, 1985, 1986, 1987 Mark Crispin
; All rights reserved

; Version components

MLSWHO==0			; who last edited MAISER (0=developers)
MLSVER==6			; MAISER's release version (matches monitor's)
MLSMIN==1			; MAISER's minor version
MLSEDT==^D161			; MAISER's edit version

	SEARCH MACSYM,MONSYM	; system definitions
	SALL			; suppress macro expansions
	.DIRECTIVE FLBLST	; sane listings for ASCIZ, etc.
	.TEXT "/NOINITIAL"	; suppress loading of JOBDAT
	.TEXT "MAISER/SAVE"	; save as MAISER.EXE
	.TEXT "/SYMSEG:PSECT:CODE" ; put symbol table and patch area in CODE
	.REQUIRE HSTNAM		; host name routines
	.REQUIRE WAKEUP		; MMailr wakeup routine
	.REQUIRE SYS:MACREL	; MACSYM support routines
IFNDEF OT%822,OT%822==:1

;  MAISER is the server to receive electronic mail from other systems via
; a network.  It implements the server half of SMTP (Simple Mail Transfer
; Protocol), the DoD standard electronic mail interchange protocol defined
; by Jon Postel in RFC 821, and documented online on the Internet as:
;	[SRI-NIC.ARPA]<NETINFO>RFC821.TXT
;
;  While nominally MAISER will be used layered on top of the DoD transport
; protocols (TCP/IP) in the Internet environment, it has been designed so
; that this is not necessary.  All I/O is done via primary I/O, and the
; Internet system call dependencies have been kept to a minimum so that the
; server can essentially support any network.
;
;  MAISER runs on TOPS-20 release 5.3 and later monitors.  MAISER will not
; run on Tenex; the "Twenex" operating system is a figment of the imagination
; of certain individuals.  There ain't no such thing as a free lunch.

; Routines invoked externally

	EXTERN $GTPRO,$GTNAM,$GTLCL,$GTHNS,$GTHSN,$GTHRL,$RMREL
	EXTERN $WAKE
	SUBTTL Assembly options

IFNDEF DATORG,<DATORG==1000>	; data on page 1
IFNDEF PAGORG,<PAGORG==100000>	; paged data on page 100
IFNDEF CODORG,<CODORG==400000>	; code on page 400
IFNDEF FTTCPBUG,<FTTCPBUG==1>	; non-zero to compensate for TCP bug which
				;  puts crud from a previous connection in our
				;  input buffer
IFNDEF TIMOCT,<TIMOCT==^D60>	; number of 5-second ticks of inactivity
				;  allowed before autologout

;  These fields have required minimum sizes established by RFC 822.  Someday
; these ought to be made to be dynamically assigned out of free storage.

IFNDEF TXTLEN,<TXTLEN==2*^D512>	; length of a text line (512 required minimum)
IFNDEF ADLLEN,<ADLLEN==2*^D256>	; length of an a-d-l (256 required minimum)
IFNDEF USRNML,<USRNML==2*^D64>	; length of a user name (64 required minimum)
IFNDEF HSTNML,<HSTNML==2*^D64>	; length of a host name (64 required minimum)
IFNDEF PDLLEN,<PDLLEN==200>	; stack length
	SUBTTL Definitions

; AC definitions

FL==:0				; flags
A=:1				; JSYS, temporary ACs
B=:2
C=:3
D=:4
E=:5				; non-JSYS temporary ACs
F=:6
G=:7
P=:17				; stack pointer

; Flags

	MSKSTR F%HLO,FL,1B0	; HELO command seen
	MSKSTR F%FRM,FL,1B1	; have a FROM specification
	MSKSTR F%TO,FL,1B2	; have a TO specification
	MSKSTR F%EOL,FL,1B3	; EOL seen
	MSKSTR F%ELP,FL,1B4	; buffer began with EOL
	MSKSTR F%EXP,FL,1B5	; EXPN vs. VRFY command
	MSKSTR F%DOP,FL,3B7	; delivery option code (see DOPTAB)
	MSKSTR F%NOK,FL,1B8	; PARMBX allows null path (for MAIL FROM:)
	MSKSTR F%MOK,FL,1B9	; PARMBX allows null domain (for RCPT TO:)
	MSKSTR F%VLH,FL,1B10	; given host name validated
	MSKSTR F%REE,FL,1B11	; reenter
	MSKSTR F%NVT,FL,1B12	; on a network terminal, must log out when done
	MSKSTR F%RFS,FL,1B13	; found a user who's refusing sends
	MSKSTR F%PRO,FL,3B15	; transport protocol:
	 P%UNK==0		; unknown
	 P%TCP==1		; TCP
	MSKSTR F%QOT,FL,1B16	; doing quoting

; Fatal assembly error macro

DEFINE .FATAL (MESSAGE) <
 PASS2
 PRINTX ?'MESSAGE
 END
>;DEFINE .FATAL

.CHLPR==:"("			; work around various macro lossages
.CHRPR==:")"
.CHRAB==:">"
	SUBTTL GTDOM% definitions

IFNDEF GTDOM%,<
	OPDEF GTDOM% [JSYS 765]

GD%LDO==:1B0			; local data only (no resolve)
GD%MBA==:1B1			; must be authoritative (don't use cache)
GD%RBK==:1B6			; resolve in background
GD%EMO==:1B12			; exact match only
GD%RAI==:1B13			; uppercase output name
GD%QCL==:1B14			; query class specified
GD%STA==:1B16			; want status code in AC1 for marginal success
  .GTDX0==:0			; total success
  .GTDXN==:1			; data not found in namespace (authoritative)
  .GTDXT==:2			; timeout, any flavor
  .GTDXF==:3			; namespace is corrupt

.GTDWT==:12			; resolver wait function
.GTDPN==:14			; get primary name and IP address
.GTDMX==:15			; get MX (mail relay) data
  .GTDLN==:0			; length of argblk (inclusive)
  .GTDTC==:1			; QTYPE (ignored for .GTDMX),,QCLASS
  .GTDBC==:2			; length of output string buffer
  .GTDNM==:3			; canonicalized name on return
  .GTDRD==:4			; returned data begins here
  .GTDML==:5			; minimum length of argblock (words)
.GTDAA==:16			; authenticate address
.GTDRR==:17			; get arbitrary RR (MIT formatted RRs)
>;IFNDEF GTDOM%
	SUBTTL Impure storage

	LOC 20			; enter low memory

FATACS:	BLOCK 20		; save of fatal ACs
.JBUUO:	BLOCK 1			; LUUO saved here
.JB41:	JSR UUOPC		; instruction executed on LUUO
UUOACS:	BLOCK 20		; save of UUO ACs

	LOC 116
.JBSYM:	BLOCK 1			; symbol table pointer
.JBUSY:	BLOCK 1			; place holder

	RELOC			; enter low segment

PDL:	BLOCK PDLLEN		; stack

UUOPC:	BLOCK 1			; PC of LUUO
	MOVEM 17,FATACS+17	; save ACs in FATACS for debugging
	MOVEI 17,FATACS		; save from 0 => FATACS
	BLT 17,FATACS+16	; ...to 16 => FATACS+16
	MOVE 17,FATACS+17	; restore AC17
	TMSG <421-Illegal instruction >
	MOVX A,.PRIOU		; output the losing LUUO
	MOVE B,.JBUUO
	MOVX C,^D8		; in octal
	NOUT%
	 NOP
	TMSG < at >
	HRRZ F,UUOPC		; output PC which lost
	CALL SYMOUT
	JRST IMPERR		; indicate impossible error and die
; Data area

	.PSECT DATA,DATORG	; enter data area

BUFFER:	BLOCK <TXTLEN/5>+1	; general purpose buffer
GTJBLK:	BLOCK <.JIBAT-.JITNO+1>	; GETJI% stores data here
TMPBUF:	BLOCK 30		; temporary buffer
IN2ACS:	BLOCK 3			; save area for ACs A-C, level 2
LEV1PC:	BLOCK 1			; PSI level 1 PC
LEV2PC:	BLOCK 1			; PSI level 2 PC
LEV3PC:	BLOCK 1			; PSI level 3 PC
TIMOUT:	BLOCK 1			; timeout count

INICBG==.			; first location cleared at once-only init
MYUSRN:	BLOCK 1			; my user number
	; Following two lines must be in this order
MYJOBN:	BLOCK 1			; my job number
MYTTYN:	BLOCK 1			; my TTY number
	; end of critical order data
MBXFRK:	BLOCK 1			; mailbox fork
MBXWIN:	BLOCK 1			; current window pointer into mailbox

; Host name/address storage

LCLHNO:	BLOCK 1			; local host address from STAT%
LCLHNC:	BLOCK 1			; local host address (in canonical form)
LCLHST:	BLOCK <HSTNML/5>+1	; local host name
FRNHNO:	BLOCK 1			; foreign host address from STAT%
FRNHST:	BLOCK <HSTNML/5>+1	; foreign host name from FRNHNO
FRNHNM:	BLOCK <HSTNML/5>+1	; foreign host name from HELO negotiation

RSTCBG==.			; first location cleared at RSET time
MLQJFN:	BLOCK 1			; queued mail file JFN
MBXBEG==.			; first mailbox location
ATDOML:	BLOCK <ADLLEN/5>+1	; at domain list specification
MAILBX:	BLOCK <USRNML/5>+1	; mailbox specification
DOMAIN:	BLOCK <HSTNML/5>+1	; domain specification
MBXEND==.-1			; last path location
RSTCEN==.-1			; last location cleared at RSET time
INICEN==.-1			; last location cleared at once-only init

	.ENDPS
; Paged data area

	.PSECT DATPAG,PAGORG	; data pages

MBXPAG:	BLOCK 2000		; for mailing list forwarding pointers
WINPAG:	BLOCK 2000		; for mailing list forwarding strings

	.ENDPS
	SUBTTL Start of program

	.PSECT CODE,CODORG	; pure code

; Entry vector

EVEC:	JRST MAISER		; START address
	JRST MAIREE		; REENTER address
	<FLD MLSWHO,VI%WHO>!<FLD MLSVER,VI%MAJ>!<FLD MLSMIN,VI%MIN>!<FLD MLSEDT,VI%EDN>
EVECL==.-EVEC

MAISER:	TDZA FL,FL		; clear flags
MAIREE:	 MOVX FL,F%REE
	RESET%			; flush all I/O
	MOVE P,[IOWD PDLLEN,PDL] ; init stack context
	SETZM INICBG		; clear once-only area
	MOVE A,[INICBG,,INICBG+1]
	BLT A,INICEN

;  It looks like a bad idea to run with capabilities, and it is.  However, a
; system which runs with account validation may cause problems when trying
; to write the queued mail file.  We also want to avoid possible problems
; with protections or quotas in the queued mail directory.

	MOVX A,.FHSLF		; get my capabilities
	RPCAP%
	IOR C,B			; enable as many capabilities as we can
	EPCAP%
	 ERJMP .+1		; ignore possible ACJ ITRAP
	MOVNI A,TIMOCT		; reset timeout count
	MOVEM A,TIMOUT
	CALL SETPSI		; set up PSIs
;  See if top-level fork, and if so assume we're a network server on an NVT.
; Note that all I/O is done via primary I/O.  This allows several ways we can
; be set up, e.g.:
; . traditional CRJOB% style running as a job on an NVT
; . on a physical terminal, as in a "TTY network" environment.
; . with primary I/O remapped to the network JFN's.

	GJINF%			; get job info
	MOVEM A,MYUSRN		; save my user number
	DMOVEM C,MYJOBN		; save job number/TTY number for later use
	IFGE. D			; can be NVT server only if attached
	  MOVX A,.FHSLF		; see what my primary I/O looks like.  If
	  GPJFN%		;  AC2 isn't -1 (.CTTRM,,.CTTRM), then we
	  ..TAGF (<AOJN B,>,)	;  can assume setup process init'd TTY
	  MOVX A,.FHTOP		; top fork
	  SETZ B,		; no handles or status
	  MOVE C,[-4,,BUFFER]	; fork structure area
	  GFRKS%		; look at fork structure
	   ERJMP .+1		; ignore error (probably GFKSX1)
	  HRRZ A,BUFFER+1	; get the top fork's handle
	  CAIE A,.FHSLF		; same as me?
	  IFSKP.
	    MOVX A,.PRIIN	; set terminal type to ideal
	    MOVX B,.TTIDL
	    STTYP%
	    MOVE B,[TT%MFF!TT%TAB!TT%LCA!TT%WKF!TT%WKN!TT%WKP!TT%WKA!<FLD .TTASC,TT%DAM>!<FLD .TTLDX,TT%DUM>]
	    SFMOD%		; has formfeed, tab, lowercase, all wakeup,
	    STPAR%		;  no translate ASCII, line half-duplex
	    DMOVE B,[BYTE (2)2,2,2,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2
		     BYTE (2)2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2]
	    SFCOC%		; disable all echoing on controls
	    MOVX A,TL%CRO!TL%COR!TL%SAB!.RHALF ; break and refuse links
	    MOVX B,.RHALF
	    TLINK%
	     ERCAL FATAL
	    MOVX A,.PRIIN	; refuse system messages
	    MOVX B,.MOSNT
	    MOVX C,.MOSMN
	    MTOPR%
	     ERCAL FATAL
	    MOVE A,[SIXBIT/MAISER/] ; set our name
	    SETNM%
IFN FTTCPBUG,<
	    MOVX A,.PRIIN	; clear possible crud in our input buffer
	    CFIBF%		;  from an earlier connection
	     ERJMP .+1
>;IFN FTTCPBUG
	    TQO F%NVT		; flag an NVT server
	  ENDIF.
	ENDIF.
; Get host info

	CALL GETTCP		; get TCP local/foreign host poop
	IFNSK.
;; calls for other networks go here
	  HRROI A,LCLHST	; otherwise get local host name any way we can
	  CALL $GTLCL
	  IFNSK.
	    TMSG <421-Unable to get local host name>
	    JRST IMPERR
	  ENDIF.
	  HRROI A,LCLHST	; remove relative relative domain from name
	  CALL $RMREL
	ENDIF.

; See if SYSTEM:DISABLE-MAIL.FLAG exists, and if so hang up

	MOVX A,GJ%SHT!GJ%OLD	; check if mail disabled now
	HRROI B,[ASCIZ/SYSTEM:DISABLE-MAIL.FLAG/]
	GTJFN%			; by seeing if this magic file exists
	IFNJE.
	  RLJFN%		; it does, flush the JFN we made
	   NOP
	  TMSG <421->
	  HRROI A,LCLHST	; output host name
	  PSOUT%
	  TMSG < SMTP service is disabled, please try again later
421 >
	  JRST QUIT1
	ENDIF.
; Here to output a banner announcing the service

	TMSG <220->		; start banner
	HRROI A,LCLHST		; output host name
	PSOUT%
	TMSG < SMTP Service >
	MOVX A,.PRIOU		; set up for primary output
	LOAD B,VI%MAJ,EVEC+2	; get major version
	MOVX C,^D8		; octal output for all version components
	NOUT%
	 ERCAL FATAL
	LOAD B,VI%MIN,EVEC+2	; get minor version
	IFN. B			; ignore if no minor version
	  MOVX A,"."		; output delimiting dot
	  PBOUT%
	  MOVX A,.PRIOU		; now output the minor version
	  NOUT%
	   ERCAL FATAL
	ENDIF.
	LOAD B,VI%EDN,EVEC+2	; get edit version
	IFN. B			; ignore if no edit version
	  MOVX A,.CHLPR		; edit delimiter
	  PBOUT%
	  MOVX A,.PRIOU		; now output the edit version
	  NOUT%
	   ERCAL FATAL
	  MOVX A,.CHRPR		; edit close delimiter
	  PBOUT%
	ENDIF.
	LOAD B,VI%WHO,EVEC+2	; get who last edited
	IFN. B			; ignore if last edited at DEC
	  MOVX A,"-"		; output delimiting hyphen
	  PBOUT%
	  MOVX A,.PRIOU		; now output the who version
	  NOUT%
	   ERCAL FATAL
	ENDIF.
	TMSG < at >
	MOVX A,.PRIOU		; output date/time
	SETO B,			; time now
	MOVX C,OT%DAY!OT%SPA!OT%TMZ!OT%SCL!OT%822 ; RFC 822 standard date/time
	ODTIM%
	 ERCAL FATAL
	TMSG <
220 Bugs/Gripes to [email protected]>
;	JRST GETCMD
	SUBTTL Command loop

GETCMD:	DO.
	  CALL CRLF		; terminate reply with CRLF
	  MOVNI A,TIMOCT	; reset timeout count
	  MOVEM A,TIMOUT
	  SETZM BUFFER		; clear out old crud in BUFFER
	  MOVE A,[BUFFER,,BUFFER+1]
	  BLT A,BUFFER+<TXTLEN/5>
	  MOVX A,.PRIIN		; from primary input
	  HRROI B,BUFFER	; pointer to command buffer
	  MOVX C,TXTLEN-1	; up to this many characters
	  MOVX D,.CHCRT		; terminate on carriage return
	  SIN%			; read a command
	   ERJMP INPEOF		; finish up on error
	  IFE. C		; if count unsatisfied, must have seen CR
	    LDB A,B		; get last byte
	    CAIN A,.CHCRT	; was it a CR?
	    IFSKP.
	      TMSG <500 Line too long>
	      LOOP.
	    ENDIF.
	  ENDIF.
	  PBIN%			; get expected LF
	   ERJMP INPEOF		; finish up on error
	  CAIN A,.CHLFD		; was it a line feed?
	  IFSKP.
	    TMSG <500 Line does not end with CRLF>
	    LOOP.
	  ENDIF.
	  SETZ A,		; make command null-terminated
	  DPB A,B
	  LDB C,[POINT 7,BUFFER,34] ; make sure space or NUL
	  CAIE C,.CHSPC
	   JUMPN C,SYNERR
	  MOVE A,BUFFER		; get command from buffer
	  ANDCM A,[BYTE (7) 040,040,040,040,177] ; upper caseify
	  MOVSI B,-CMDTBL	; length of command table
	  DO.
	    CAME A,CMDTAB(B)	; command matches?
	     AOBJN B,TOP.	; try next command
	  ENDDO.
	  JRST @CMDDSP(B)	; dispatch to command
	ENDDO.
	SUBTTL Command table and dispatch

DEFINE COMMANDS <
; "Minimum required for an SMTP implementation" commands
	CMD HELO
	CMD MAIL
	CMD RCPT
	CMD DATA
	CMD RSET
	CMD NOOP
	CMD QUIT
; "Optional" commands
	CMD SEND
	CMD SOML
	CMD SAML
	CMD VRFY
	CMD EXPN
	CMD HELP
	CMD TURN
>;DEFINE COMMANDS

DEFINE CMD (CM) <ASCII/'CM'/>

CMDTAB:	COMMANDS		; command names
CMDTBL==.-CMDTAB

DEFINE CMD (CM) <.'CM>

CMDDSP:	COMMANDS		; command dispatch
	BADCMD			; here if command not found
	SUBTTL Command service routines

; HELO - HELLO: negotiate identities

.HELO:	TQZ <F%HLO,F%VLH>	; cancel valid HELO and host validated
	JUMPE C,MISARG		; must have argument
	SETZM FRNHNM
	DMOVE A,[POINT 7,BUFFER+1 ; pointer to foreign host name
		 POINT 7,FRNHNM] ; where we store it
	MOVX D,HSTNML		; length of a host name
	CALL GETDOM		; get domain name
	 JRST SYNFLD
	JUMPN C,SYNFLD		; error if not newline here
	LOAD A,F%PRO		; get protocol used
	CAIN A,P%TCP		; TCP?
	IFSKP.
	  TQO F%HLO		; HELO is valid
	  HRROI D,[ASCIZ/ - Your name accepted but not validated/] ; no
	ELSE.
	  SKIPE FRNHST		; got foreign host name yet?
	  IFSKP.
	    HRROI A,FRNHST	; get foreign host name
	    MOVE B,FRNHNO	; from foreign address
	    CALL $GTHNS
	    IFNSK.
	      TMSG <421-Unable to get foreign host name>
	      JRST IMPERR
	    ENDIF.
	    HRROI A,FRNHST	; remove relative domain from name
	    CALL $RMREL
	  ENDIF.
	  HRROI A,FRNHNM	; see if name is a literal
	  CALL $GTHRL		; parse it and return address in B
	  IFSKP.
	    CAME B,FRNHNO	; read a literal, address matches?
	    IFSKP.
	      TQO <F%HLO,F%VLH> ; yes, note host name validated
	    ELSE.
	      MOVE C,B		; in case needed to restore
	      HRROI A,BUFFER	; canonicalize address: get name for address
	      CALL $GTHNS
	      IFSKP.
		HRROI A,BUFFER
		CALL $RMREL
		HRROI A,BUFFER	; see if that name matches
		HRROI B,FRNHST
		STCMP%
		IFE. A
		  TQO <F%HLO,F%VLH> ; yes, note host name validated
		ELSE.
		  HRROI A,BUFFER ; now get the address from the name
		  CALL $GTHSN
		   MOVE B,C	; restore address after failure
	        ENDIF.
	      ELSE.
		MOVE B,C	; restore address after failure
	      ENDIF.
	    ENDIF.
	  ELSE.
	    HRROI A,FRNHNM	; point to her claimed foreign host name
	    HRROI B,FRNHST	; compare with what we think it is
	    STCMP%		; got a match?
	    IFE. A
	      TQO <F%HLO,F%VLH>	; yes, note host name validated
	    ELSE.
	      MOVX A,.GTDAA	; authenticate address
	      HRROI B,FRNHNM	; from claimed name
	      MOVE C,FRNHNO	; and its address
	      GTDOM%
	      IFNJE.
		TQO <F%HLO,F%VLH> ; note validated if OK
	      ELSE.
		HRROI A,FRNHNM	; point to claimed name
		CALL $GTHSN	; get its address
		 SETO B,	; unknown name
	      ENDIF.
	    ENDIF.
	  ENDIF.
	ANDQE. F%HLO		; if we're still not certain...
	  CAMN B,LCLHNC		; check for mirror connections
	  IFSKP.
	    TQO F%HLO		; HELO is valid
	    SKIPGE B
	     SKIPA D,[-1,,[ASCIZ/ - Never heard of that name/]]
	      HRROI D,[ASCIZ/ - You are a charlatan/]
	  ELSE.
	    HRROI A,LCLHST	; could be...allow it if it really is me!
	    HRROI B,FRNHST
	    STCMP%
	    SKIPN A
	     TQOA <F%HLO,F%VLH> ; this can happen when going by the numbers
	      HRROI D,[ASCIZ/ - You can't impersonate me/]
	  ENDIF.
	ENDIF.
	TQNN F%HLO		; have a valid HELO?
	 SKIPA A,[-1,,[ASCIZ/501 /]] ; HELO failure reply
	  HRROI A,[ASCIZ/250 /]	; HELO success reply
	PSOUT%
	HRROI A,LCLHST		; output our name
	PSOUT%
	TQNN F%VLH		; host name validated?
	 SKIPA A,D		; no, output auxillary message
	  HRROI A,[ASCIZ/ - Hello/]
	PSOUT%
	SKIPN FRNHST		; do we know who foreign host is?
	IFSKP.
	  TMSG <, >		; yes, prepare to output it
	  HRROI A,FRNHST	; output foreign host's registered name
	  PSOUT%
	ENDIF.
	JRST RSET2		; enter RSET code
; RSET - RESET state to initial

.RSET:	JUMPN C,BADARG		; can't have an argument
RSET1:	TMSG <250 OK>		; acknowledge command
RSET2:	SKIPN A,MLQJFN		; if a queue file open, flush its JFN
	IFSKP.
	  TXO A,CZ%ABT		; abort it
	  CLOSF%
	   ERCAL FATAL		; why should this fail?
	ENDIF.
	CALL SETPSI		; set up PSIs
	SETZM RSTCBG		; clear reset area
	MOVE A,[RSTCBG,,RSTCBG+1]
	BLT A,RSTCEN
	TQZ <F%FRM,F%TO>	; no more FROM or TO specification known
	JRST GETCMD
; VRFY - VERIFY mailbox
; EXPN - EXPAND mailing list

.VRFY:	TQZA F%EXP		; flag not expand
.EXPN:	 TQO F%EXP		; flag expand
	JUMPE C,MISARG		; must have an argument
	DMOVE A,[POINT 7,BUFFER+1 ; command argument
		 POINT 7,MAILBX] ; where we load mailbox
	MOVX D,USRNML		; maximum length of a name
	ILDB C,A		; get first byte
	JUMPE C,MISARG		; missing argument
	CAIE C,""""		; quoted string?
	IFSKP.
	  DO.
	    ILDB C,A		; get next byte to consider
	    CAIN C,""""		; end of quoted string?
	    IFSKP.
	      SOJL D,SYNFLD	; no, make sure field isn't too large
	      JUMPE C,SYNFLD	; also make sure no premature end of line
	      IDPB C,B		; store byte in string
	      LOOP.		; get next byte
	    ENDIF.
	  ENDDO.
	  ILDB C,A		; get final byte
	  JUMPN C,SYNFLD	; make sure line ends here
	ELSE.
	  DO.
	    MOVEI E,(C)		; get copy of character
	    IDIVI E,^D32	; E/ word to check, F/ bit to check
	    MOVNS F
	    MOVX G,1B0		; make bit to check
	    LSH G,(F)
	    TDNE G,SPCMSK(E)	; is it a special character?
	     JRST SYNERR	; it is, lose
	    CAIE C,.CHRAB	; disallow broket and at as specials
	     CAIN C,"@"
	      JRST SYNERR
	    CAIN C,"\"		; quote next byte literally?
	     ILDB C,A		; yes, get next byte
	    IDPB C,B		; store byte in string
	    ILDB C,A		; get next byte to consider
	    SOJL D,SYNFLD	; field too large
	    JUMPN C,TOP.	; if non-null, continue parse
	  ENDDO.
	ENDIF.
	IDPB C,B		; tie off string
	HRROI A,MAILBX		; point to mailbox
	CALL RUNMBX		; validate address
	IFNSK.
	  SKIPE MBXFRK		; did mailbox fork run successfully?
	  IFSKP.
	    TMSG <451 Mailbox lookup process terminated abnormally>
	    JRST GETCMD
	  ENDIF.
	  SKIPG MBXFRK		; couldn't find mailbox fork?
	   JRST NOTIMP		; command not implemented
	  TMSG <550 No such local mailbox as ">
	  HRROI A,MAILBX	; output the bad mailbox
	  PSOUT%
	  TMSG <", not verified>
	  JRST GETCMD
	ENDIF.
	IFQE. F%EXP		; EXPN or VRFY?
	  TMSG (250 <)		; VRFY, just echo back the mailbox name given
	  HRROI A,MAILBX
	  PSOUT%
	  MOVX A,"@"
	  PBOUT%
	  HRROI A,LCLHST
	  PSOUT%
	  MOVX A,.CHRAB
	  PBOUT%
	ELSE.
	  SKIPE MBXPAG+300	; some answer must be returned
	  IFSKP.
	    TMSG <451 Mailbox lookup process returned null answer>
	    JRST GETCMD
	  ENDIF.
	  MOVEI D,MBXPAG+300	; pointer to list of addresses
	  DO.
	    SKIPN C,(D)		; if end of list, return
	     EXIT.
	    SKIPN 1(D)		; is this the last item on the list?
	     SKIPA A,[-1,,[ASCIZ/250 </]] ; yes, no continuation
	      HRROI A,[ASCIZ/250-</] ; no, indicate continuation coming
	    PSOUT%		; output reply code and opening broket
	    TXNN C,.RHALF	; local user reply?
	     MOVSS C		; yes, set up as local address reply
	    HRRZ A,C		; get user address
	    CALL INFOUT		; output string from inferior
	    MOVX A,"@"		; output mailbox/host delimiter
	    PBOUT%
	    IFXE. C,.LHALF	; was a host specified?
	      HRROI A,LCLHST	; no, output local host name
	      PSOUT%
	    ELSE.
	      HLRZ A,C		; use specified host name
	      CALL INFOUT	; output string from inferior
	    ENDIF.
	    MOVX A,.CHRAB
	    PBOUT%
	    SKIPE 1(D)		; is this the last item on the list?
	     CALL CRLF		; no, output CRLF delimiter
	    AOJA D,TOP.		; continue until done
	  ENDDO.
	ENDIF.
	JRST GETCMD
DOPTAB:	PHASE 0			; delivery option names and F%DOP indices
D%MAIL:!ASCIZ/MAIL/		; mail
D%SEND:!ASCIZ/SEND/		; send
D%SOML:!ASCIZ/SOML/		; send or mail
D%SAML:!ASCIZ/SAML/		; send and mail
IFN <.-4>,<.FATAL Incorrect number of delivery options>
	DEPHASE

; SEND - initiate SEND transaction

.SEND:	JUMPE C,MISARG		; must have an argument
	JE F%HLO,,HLOREQ	; bad sequence if HELO not done yet
	JN F%FRM,,INPROG	; bad sequence if transaction already started
	MOVX A,D%SEND		; set delivery option
	JRST MAKQUE		; make a queued mail file

; SOML - initiate SEND transaction, mail if not on-line

.SOML:	JUMPE C,MISARG		; must have an argument
	JE F%HLO,,HLOREQ	; bad sequence if HELO not done yet
	JN F%FRM,,INPROG	; bad sequence if transaction already started
	MOVX A,D%SOML		; set delivery option
	JRST MAKQUE		; make a queued mail file

; SAML - initiate SEND transaction and mail

.SAML:	JUMPE C,MISARG		; must have an argument
	JE F%HLO,,HLOREQ	; bad sequence if HELO not done yet
	JN F%FRM,,INPROG	; bad sequence if transaction already started
	MOVX A,D%SAML		; set delivery option
	JRST MAKQUE		; make a queued mail file

; Table of devices to queue mail to

MLQTAB:	-1,,[ASCIZ/MAILQ:/]	; MAILQ: is the official directory
	-1,,[ASCIZ/SYSTEM:/]	; if not, MMAILR still scans SYSTEM:
	-1,,[ASCIZ/DSK:/]	; otherwise must use connected directory
MLQTBL==.-MLQTAB

; MAIL - initiate MAIL transaction

.MAIL:	JUMPE C,MISARG		; must have an argument
	JE F%HLO,,HLOREQ	; bad sequence if HELO not done yet
	JN F%FRM,,INPROG	; bad sequence if transaction already started
	MOVX A,D%MAIL		; set delivery option
;	JRST MAKQUE		; make a queued mail file
; Make a mailer queued request file

MAKQUE:	STOR A,F%DOP		; set delivery options
	MOVE A,BUFFER+1		; get what comes after MAIL<SP>
	ANDCM A,[BYTE (7) 040,040,040,040,000] ; uppercaseify if needed
	CAME A,[ASCII/FROM:/]	; was it MAIL FROM:, etc.?
	 JRST SYNERR		; no, syntax error
	MOVE A,[POINT 7,BUFFER+2] ; start parse after the colon
	TQO F%NOK		; allow null mailbox
	TQZ F%MOK		; if mailbox non-null, must have domain
	CALL PARMBX		; parse a mailbox
	 JRST SYNFLD		; syntax error in mailbox
	MOVSI D,-MLQTBL		; pointer to table of mail queue devices
	DO.
	  HRROI A,TMPBUF	; pointer to name of queued mail file we build
	  MOVE B,MLQTAB(D)	; get device to try
	  SETZ C,
	  SOUT%
	  HRROI B,[ASCIZ/[--QUEUED-MAIL--].NEW-/]
	  SOUT%			; set up initial part of name
	  PUSH P,A		; save string pointer
	  GTAD%			; get system date/time
	  MOVE B,A		; now output it in octal
	  POP P,A
	  MOVX C,^D8
	  NOUT%
	   ERCAL FATAL
	  HRROI B,[ASCIZ/-MAISER-J/] ; add originating process name
	  SETZ C,
	  SOUT%
	  HRRZ B,MYJOBN		; insert job number for unique name
	  MOVX C,^D10		; in decimal
	  NOUT%
	   ERCAL FATAL
	  HRROI B,[ASCIZ/.-1;P770000/] ; next generation, protection 770000
	  SETZ C,
	  SOUT%
	  MOVX A,GJ%NEW!GJ%FOU!GJ%PHY!GJ%SHT ; want new file
	  HRROI B,TMPBUF	; with name we build
	  GTJFN%		; try to get JFN on it
	  IFJER.
	    AOBJN D,TOP.	; can't do it, try alternative place
	    TMSG <421-Unable to get queue file - >
	    CALL ERROUT		; output last JSYS error
	    JRST IMPERR		; now die
	  ENDIF.
	  MOVEM A,MLQJFN	; save JFN for later use
	  MOVX B,<<FLD 7,OF%BSZ>!OF%WR> ; open for write, 7-bit bytes
	  OPENF%
	  IFJER.
	    MOVE A,MLQJFN	; OPENF% failed, release the JFN
	    RLJFN%
	     ERJMP .+1
	    SETZM MLQJFN	; forget about it
	    AOBJN D,TOP.	; can't do it, try alternative place
	    TMSG <421-Unable to open queue file - >
	    CALL ERROUT		; output last JSYS error
	    JRST IMPERR		; now die
	  ENDIF.
	ENDDO.
	SETZ C,			; make C be 0 for SOUT%'ing below
	SKIPN FRNHST		; foreign host number known?
	IFSKP.
	  MOVX B,.CHFFD		; yes, write a NET-MAIL-FROM-HOST line
	  BOUT%
	   ERCAL FATAL
	  HRROI B,[ASCIZ/=NET-MAIL-FROM-HOST:/]
	  SOUT%
	   ERCAL FATAL
	  HRROI B,FRNHST	; output host name
	  SOUT%
	   ERCAL FATAL
	  HRROI B,[ASCIZ/
/]				; output trailing CRLF
	  SOUT%
	   ERCAL FATAL
	ENDIF.
	MOVX B,.CHFFD		; write delivery options line
	BOUT%
	 ERCAL FATAL
	HRROI B,[ASCIZ/=DELIVERY-OPTIONS:/]
	SOUT%
	 ERCAL FATAL
	LOAD B,F%DOP		; get delivery options
	HRROI B,DOPTAB(B)
	SOUT%
	 ERCAL FATAL
	HRROI B,[BYTE (7) .CHCRT,.CHLFD,.CHFFD]
	SOUT%
	 ERCAL FATAL
	SKIPE MAILBX		; was a proper return path specified?
	IFSKP.
	  HRROI B,[ASCIZ/=DISCARD-ON-ERROR/]
	  SOUT%			; no, failures go to a black hole
	ELSE.
	  HRROI B,[ASCIZ/=RETURN-PATH:/]
	  SOUT%
	   ERCAL FATAL
	  SKIPN ATDOML		; is an at-domain-list defined?
	  IFSKP.
	    HRROI B,ATDOML
	    SOUT%
	     ERCAL FATAL
	  ENDIF.
	  MOVE B,[POINT 7,MAILBX] ; now output Mailbox
	  CALL MBXOUT
	  MOVX B,"@"		; mailbox/domain delimiter
	  BOUT%
	   ERCAL FATAL
	  HRROI B,DOMAIN	; output domain
	  SOUT%
	   ERCAL FATAL
	  HRROI B,[BYTE (7) .CHCRT,.CHLFD,.CHFFD,"_"]
	  SOUT%			; write sender specification
	   ERCAL FATAL
	  HRROI B,DOMAIN	; output domain
	  SOUT%
	   ERCAL FATAL
	  HRROI B,[BYTE (7) .CHCRT,.CHLFD]
	  SOUT%
	   ERCAL FATAL
	  HRROI B,MAILBX	; output mailbox
	  SOUT%
	   ERCAL FATAL
	ENDIF.
	HRROI B,[BYTE (7) .CHCRT,.CHLFD,.CHFFD]
	SOUT%
	 ERCAL FATAL
	TQO F%FRM		; flag "from" part of transaction complete
	TMSG <250 >		; acknowlege command
	LOAD A,F%DOP		; get delivery options
	HRROI A,DOPTAB(A)
	PSOUT%
	TMSG < accepted>
	JRST GETCMD		; get next command
; RCPT - identify a RECIPIENT for this transaction

.RCPT:	JUMPE C,MISARG		; must have an argument
	JE F%FRM,,MAIREQ	; bad sequence if transaction not started yet
	MOVE A,BUFFER+1		; get what comes after RCPT<SP>
	ANDCM A,[BYTE (7) 040,040,000,177,177] ; uppercaseify if needed
	CAME A,[ASCII/TO:/]	; was it RCPT TO:?
	 JRST SYNERR		; no, syntax error
	MOVE A,[POINT 7,BUFFER+1,20] ; start parse after the colon
	TQZ F%NOK		; do not allow null mailbox
	TQO F%MOK		; if domain null, assume local host
	CALL PARMBX		; parse a mailbox
	 JRST SYNFLD		; syntax error
	SKIPN DOMAIN		; if domain given, see if our own
	IFSKP.
	  HRROI A,DOMAIN	; look up recipient host name
	  SETO C,		; through all naming registries
	  CALL $GTPRO		; get address and registry
	  IFNSK.
	    TMSG <550 Host name ">
	    HRROI A,DOMAIN	; output the bad host
	    PSOUT%
	    TMSG <" unknown, recipient rejected>
	    JRST GETCMD
	  ENDIF.
	  MOVE D,B		; save address
	  HRROI A,BUFFER	; store local name out of the way
	  SETO B,		; want local address for this protocol
	  CALL $GTNAM		; get local name
	  IFNSK.
	    TMSG <421-Unable to get local host for recipient naming registry>
	    JRST IMPERR
	  ENDIF.
	  CAMN B,D		; was destination host in fact us?
	   SETZM DOMAIN		; yes, note local domain
	ENDIF.
	SKIPE DOMAIN		; local domain?
	IFSKP.
	  LOAD A,F%DOP		; get delivery option
	  CAIE A,D%SEND		; SEND?
	  IFSKP.
	    MOVX A,RC%EMO	; yes, see if local user name
	    HRROI B,MAILBX
	    RCUSR%
	    IFJER.
	      TMSG <550-Invalid username ">
	      HRROI A,MAILBX	; output the bad mailbox
	      PSOUT%
	      TMSG <", recipient rejected
550 Use SOML if you're trying to do a third-party send>
	      JRST GETCMD
	    ENDIF.
	    IFXN. A,RC%NOM!RC%AMB ;Parsed, does it exist?
	      TMSG <550-No such local user as ">
	      HRROI A,MAILBX	; output the bad mailbox
	      PSOUT%
	      TMSG <", recipient rejected
550 Use SOML if you're trying to send to a mailing list>
	      JRST GETCMD
	    ENDIF.
	    TQZ F%RFS		; no online users refusing sends yet
	    MOVX D,1		; initial job number for scan
	    MOVE E,C		; user number to look for in E
	    DO.
	      MOVEI A,(D)	; job number to sniff at
	      MOVE B,[-<.JIBAT-.JITNO+1>,,GTJBLK]
	      MOVX C,.JITNO	; get TTY #, user #, ..., batch flag
	      GETJI%
	      IFJER.
		CAIN A,GTJIX4	; No such job?
		 AOJA D,TOP.	; yes, try next higher job number
		TMSG <450 User ">
		HRROI A,MAILBX	; output the bad mailbox
		PSOUT%
		TQNE F%RFS	; was there an online job refusing?
		 SKIPA A,[-1,,[ASCIZ/" is refusing sends/]]
		  HRROI A,[ASCIZ/" is not online now/]
		PSOUT%
		TMSG <, try again later>
		JRST GETCMD
	      ENDIF.
	      SKIPE GTJBLK+<.JIBAT-.JITNO> ; is this a batch job?
	       AOJA D,TOP.	; yes, skip it
	      SKIPL A,GTJBLK	; attached to a terminal
	       CAME E,GTJBLK+<.JIUNO-.JITNO> ; yes, the user we want?
		AOJA D,TOP.	; no to either, try next job
	      TXO A,.TTDES	; make it a device designator
	      MOVX B,.MORNT	; does user want system messages?
	      MTOPR%
	      IFNJE.
		JUMPE C,ENDLP.	; found a logged in user receiving sends, done!
	      ENDIF.
	      TQO F%RFS		; found an online user who's refusing
	      AOJA D,TOP.	; otherwise try next job
	    ENDDO.
	  ELSE.
	    TQZ F%EXP		; don't expand here
	    HRROI A,MAILBX
	    CALL RUNMBX		; validate address
	  ANNSK.
	    SKIPE MBXFRK	; failed, did mailbox fork run successfully?
	    IFSKP.
	      TMSG <451 Mailbox lookup process terminated abnormally>
	      JRST GETCMD
	    ENDIF.
	    SKIPG MBXFRK	; is there a mailbox fork?
	  ANSKP.
	    TMSG <550 No such local mailbox as ">
	    HRROI A,MAILBX	; output the bad mailbox
	    PSOUT%
	    TMSG <", recipient rejected>
	    JRST GETCMD
	  ENDIF.
	ENDIF.
	SKIPE A,MLQJFN		; get JFN of queue file
	IFSKP.
	  TMSG <421-Queue not set up in RCPT command>
	  JRST IMPERR
	ENDIF.
	SKIPN DOMAIN		; domain specified?
	 SKIPA B,[-1,,LCLHST]	; no, use local host as default domain
	  HRROI B,DOMAIN	; output destination domain
	SETZ C,
	SOUT%
	 ERCAL FATAL
	HRROI B,[ASCIZ/
/]
	SOUT%
	 ERCAL FATAL
	HRROI B,MAILBX		; now output destination mailbox
	SOUT%
	 ERCAL FATAL
	HRROI B,[BYTE (7) .CHCRT,.CHLFD,.CHFFD]
	SOUT%
	 ERCAL FATAL
	TQO F%TO		; flag "to" part of transaction complete
	TMSG <250 Recipient accepted> ; acknowledge
	JRST GETCMD		; and get next command
; DATA - DATA for mail transaction

.DATA:	JUMPN C,BADARG		; must not have an argument
	JE F%TO,,RCPREQ		; have FROM/TO specifications?
	SKIPE A,MLQJFN		; get JFN of queue file
	IFSKP.
	  TMSG <421-Queue not set up in DATA command>
	  JRST IMPERR
	ENDIF.
	LOAD B,F%DOP		; get delivery option
	CAIN B,D%SEND		; if SEND, don't add Received: header
	IFSKP.
	  HRROI B,[ASCIZ/
Received: from /]		; now, write Received line
	  SETZ C,
	  SOUT%
	   ERCAL FATAL
	  HRROI B,FRNHNM	; write foreign host
	  SOUT%
	   ERCAL FATAL
	  IFQE. F%VLH		; foreign host number validated?
	    HRROI B,[ASCIZ/ (/]	; no, start a comment
	    SOUT%
	     ERCAL FATAL
	    SKIPN FRNHST	; foreign host known?
	     SKIPA B,[-1,,[ASCIZ/not validated/]]
	      HRROI B,FRNHST	; output foreign host name
	    SOUT%
	     ERCAL FATAL
	    MOVX B,.CHRPR	; terminate comment
	    BOUT%
	     ERCAL FATAL
	  ENDIF.
	  HRROI B,[ASCIZ/ by /]
	  SOUT%
	   ERCAL FATAL
	  HRROI B,LCLHST	; write local host
	  SOUT%
	   ERCAL FATAL
	  HRROI B,[ASCIZ/; /]	; default is no With specification
	  LOAD D,F%PRO		; get protocol used
	  CAIN D,P%TCP		; TCP?
	   HRROI B,[ASCIZ/ with TCP; /]
	  SOUT%
	   ERCAL FATAL
	  SETO B,		; output current date/time
	  MOVX C,OT%DAY!OT%SPA!OT%TMZ!OT%SCL!OT%822 ; RFC 822 standard date/time
	  ODTIM%
	   ERCAL FATAL
	ENDIF.
	HRROI B,[ASCIZ/
/]				; now output terminating CRLF
	SETZ C,
	SOUT%
	 ERCAL FATAL
	TMSG <354 Start mail input; end with <CRLF>.<CRLF>>
	CALL CRLF
	TQZ F%EOL		; no EOL seen on this line yet
	SETO E,			; no lookahead yet
	DO.
	  MOVNI A,TIMOCT	; reset timeout count
	  MOVEM A,TIMOUT
	  MOVE B,[POINT 7,BUFFER] ; pointer to buffer
	  MOVX C,TXTLEN-1	; up to this many characters
	  SKIPGE A,E		; any lookahead byte?
	  IFSKP.
	    SETO E,		; yes, no lookahead now
	    IDPB A,B		; stash it in the buffer
	    SUBI C,1		; account for it
	    CAIE A,.CHCRT	; was it a CR?
	  ANSKP.		; if so don't read anything
	  ELSE.
	    MOVX A,.PRIIN	; read a line from primary input
	    MOVX D,.CHCRT	; terminate on carriage return
	    SIN%
	     ERJMP INPEOF	; finish up on error
	    LDB A,B		; get last character read
	  ENDIF.
	  CAIE A,.CHCRT		; was it a CR?
	  IFSKP.
	    PBIN%		; yes, get byte after CR
	     ERJMP INPEOF	; finish up on error
	    CAIE A,.CHLFD	; is this a real EOL?
	    IFSKP.
	      IDPB A,B		; yes, insert it in the buffer
	      SUBI C,1		; account for it in the buffer
	      TQO F%EOL		; flag EOL seen
	    ELSE.
	      MOVE E,A		; set lookahead byte after CR
	    ENDIF.
	  ENDIF.
	  MOVE B,[POINT 7,BUFFER] ; buffer we read into
	  SUBI C,TXTLEN-1	; negative count of bytes to output
	  IFQN. F%ELP		; buffer begin with EOL?
	    LDB A,[POINT 7,BUFFER,6] ; yes, get first byte of buffer
	    CAIE A,"."		; was it a period?
	    IFSKP.
	      IBP B		; yes, skip over it
	      ADDI C,1		; account for it in the count
	      IFQN. F%EOL	; buffer end with EOL?
		CAMN C,[-2]	; yes, only two bytes to output?
		 EXIT.		; yes, must be EOM
	      ENDIF.
	    ENDIF.
	  ENDIF.
	  MOVE A,MLQJFN		; output buffer to queue file
	  SOUT%
	   ERCAL FATAL
	  TQZE F%EOL		; EOL seen?
	   TQOA F%ELP		; yes, set EOL seen in previous buffer
	    TQZ F%ELP		; no EOL in previous buffer
	  LOOP.
	ENDDO.
	MOVE A,MLQJFN		; yes, must be EOM
	CLOSF%
	 ERCAL FATAL
	SETZM MLQJFN		; flush the JFN
	TMSG <250-Message accepted and queued for delivery
>
	CALL $WAKE		; wake up MMailr
	JRST RSET1		; now do an implicit RSET
; QUIT - QUIT out of mail service

.QUIT:	JUMPN C,BADARG		; must not have an argument
	TMSG <221 >		; start acknowledgement
QUIT1:	HRROI A,LCLHST		; output our host name
	PSOUT%
	TMSG < Service closing transmission channel>
	CALL CRLF
INPEOF:	CALL HANGUP		; hang up the connection
	JRST MAISER		; restart program

HANGUP:	SKIPN A,MLQJFN		; if a queue file open, flush its JFN
	IFSKP.
	  TXO A,CZ%ABT		; abort it
	  CLOSF%
	   ERJMP .+1		; why should this fail?
	  SETZM MLQJFN		; flush JFN
	ENDIF.
	MOVX A,.PRIOU		; wait until the output happens
	DOBE%
	 ERJMP .+1
	IFQN. F%NVT		; NVT server?
	  DTACH%		; detach the job to prevent "Killed..." message
	   ERJMP .+1
	  SETO A,		; now log myself out
	  LGOUT%
	   ERJMP .+1
	ENDIF.
	HALTF%			; stop
	RET
; NOOP - NOOP null command

.NOOP:	JUMPN C,BADARG		; must not have an argument
	TMSG <250 OK>		; acknowledge command
	JRST GETCMD

; HELP - HELP message

.HELP:	JUMPN C,BADARG		; must not have an argument
	HRROI A,HLPMSG		; output help message
	PSOUT%
	JRST GETCMD

HLPMSG:	ASCIZ/214-The following commands are implemented:
214- HELO, MAIL, RCPT, DATA, RSET, NOOP, QUIT, SEND, SOML, SAML,
214- VRFY, EXPN, HELP, TURN
214 This system is a DECSYSTEM-20 running the TOPS-20 operating system/
; TURN - TURN around transaction

.TURN:	JUMPN C,BADARG		; must not have an argument
	TMSG <250 TURN command accepted, send 220 greeting>
	CALL CRLF
	CALL RDRPLY		; read SMTP reply
	CAME A,[ASCII/220/]	; 220 greeting?
	IFSKP.
	  TMSG <HELO >		; yes, output HELO
	  HRROI A,LCLHST	; and local host name
	  PSOUT%
	  CALL CRLF
	  CALL RDRPLY
; *** Here would go code to support a future implementation of outgoing mail.
; The purpose of this is for situations where two-way mail interactions on
; the same connection are useful.
	ENDIF.
	CAMN A,[ASCII/421/]	; was last reply code a 421 hangup?
	IFSKP.
	  TMSG <QUIT>
	  CALL CRLF		; no, negotiate a normal QUIT
	  CALL RDRPLY		; get reply for it
	ENDIF.
	CALL HANGUP		; hang up the connection
	JRST MAISER		; restart
;  Read SMTP reply from server process (for TURN command).  Returns ASCII
; of reply code in A.

RDRPLY:	DO.
	  SETZM BUFFER		; make sure no random crud here
	  MOVX A,.PRIIN		; from primary input
	  HRROI B,BUFFER	; pointer to command buffer
	  MOVX C,TXTLEN-1	; up to this many characters
	  MOVX D,.CHCRT		; terminate on carriage return
	  SIN%			; read the greeting header
	   ERJMP INPEOF		; finish up on error
	  LDB A,B		; get last byte of line
	  DO.			; slurp up bytes until see a CRLF
	    CAIN A,.CHCRT	; got a CR?
	    IFSKP.
	      PBIN%		; no, read next byte
	       ERJMP INPEOF	; finish up on error
	      LOOP.		; see if this one looks good
	    ENDIF.
	    PBIN%		; get expected LF
	     ERJMP INPEOF	; finish up on error
	    CAIE A,.CHLFD	; saw LF?
	     LOOP.		; no, start over again
	  ENDDO.
	  LDB A,[POINT 7,BUFFER,27] ; get possible continuation byte
	  CAIN A,"-"		; was continuation specified?
	   LOOP.		; yes, get new line
	  CAIE A," "		; single reply seen?
	   CALL HANGUP		; no, something's wrong - punt
	ENDDO.
	MOVE A,BUFFER		; get reply code
	AND A,[BYTE (7) 177,177,177,000,000] ; without text crud
	RET			; return to caller
	SUBTTL Subroutines

;  Here to parse a mailbox specification pointed to in A.  Skips if success.
; Returns a-d-l in ATDOML, mailbox in MAILBX, and domain in DOMAIN.
; F%NOK indicates that a null mailbox is allowed, to allow null return-paths
; per the SMTP specification.
; F%MOK indicates that a domain is optional, that is, the command:
;	RCPT TO:<FOO>
; will be interpreted as local mailbox FOO.

PARMBX:	SETZM MBXBEG		; clear previous mailbox
	MOVE C,[MBXBEG,,MBXBEG+1]
	BLT C,MBXEND
	ILDB C,A		; get opening character
	CAIE C,"<"		; must be opening broket
	 RET			; parse fails
	ILDB C,A		; get first character in path
	CAIE C,.CHRAB		; is this a close broket?
	IFSKP.
	  JN F%NOK,,PRMDUN	; yes, if null mailbox okay then return success
	ENDIF.
	CAIE C,"@"		; a-d-l present?
	IFSKP.
	  MOVE B,[POINT 7,ATDOML] ; set up pointer to a-d-l
	  IDPB C,B		; store the starting "@"
	  MOVX D,ADLLEN-1	; set up limit of domain list length
	  DO.
	    CALL GETDOM		; get a domain
	     RET		; syntax error in domain
	    CAIE C,","		; another domain in route list?
	    IFSKP.
	      IDPB C,B		; yes, save the comma
	      SOJL D,R		; count the comma
	      ILDB C,A		; get next byte
	      CAIE C,"@"	; start of next at-domain?
	      IFSKP.
		IDPB C,B	; yes, store this "@"
		SOJGE D,TOP.	; count the "@"
		RET		; no more space
	      ENDIF.
	      MOVX D,":"	; no, must be an RFC 788 SMTP sender, patch
	      DPB D,B		;  a colon over the comma and exit
	    ELSE.
	      CAIE C,":"	; end of domain?
	       RET		; no, syntax error in domain
	      IDPB C,B		; save a-d-l terminator
	      SOJL D,R		; let's count that terminator as well
	      ILDB C,A		; get first character of local part
	    ENDIF.
	  ENDDO.
	ENDIF.
; Here to process the local part of a mailbox, C has first character

	MOVE B,[POINT 7,MAILBX]	; set up pointer to mailbox
	MOVX D,USRNML		; set up maximum length of user name
	CAIE C,""""		; quoted string?
	IFSKP.
	  DO.
	    ILDB C,A		; yes, get next quoted byte
	    CAIE C,""""		; end of quoted string?
	    IFSKP.
	      ILDB C,A		; get expected at
	      CAIN C,"@"	; was it an at?
	       EXIT.		; saw an at, finished with mailbox
	      CAIN C,.CHRAB	; is this a close broket?
	       SKIPN MAILBX	; yes, was mailbox non-null?
		RET		; not close broket or mailbox null, syntax err
	      JN F%MOK,,PRMDUN	; yes, if F%MOK then allow missing domain
	      RET		; syntax error
	    ENDIF.
	    CAIE C,.CHCRT	; CR or LF invalid in quoted string
	     CAIN C,.CHLFD
	      RET
	    CAIN C,"\"		; quote next byte literally?
	     ILDB C,A		; yes, get next byte
	    IDPB C,B		; store byte in string
	    SOJGE D,TOP.	; continue with next byte unless overflowed
	    RET			; mailbox name too long
	  ENDDO.
	ELSE.
	  DO.			; parse unquoted string
	    MOVEI E,(C)		; get copy of character
	    IDIVI E,^D32	; E/ word to check, F/bit to check
	    MOVNS F
	    MOVX G,1B0		; make bit to check
	    LSH G,(F)
	    TDNE G,SPCMSK(E)	; is it a special character?
	     RET		; yes, syntax error
	    CAIE C,.CHRAB	; saw close broket?
	    IFSKP.
	      SKIPN MAILBX	; yes, was mailbox non-null?
	       RET		; no, syntax error
	      JN F%MOK,,PRMDUN	; if F%MOK then allow missing domain
	      RET		; else syntax error
	    ENDIF.
	    CAIN C,"@"		; was it an at?
	    IFSKP.
	      CAIN C,"\"	; quote next byte literally?
	       ILDB C,A		; yes, get next byte
	      IDPB C,B		; store byte in string
	      ILDB C,A		; get next byte to consider
	      SOJGE D,TOP.	; continue byte unless overflowed
	      RET
	    ENDIF.
	  ENDDO.
	ENDIF.

; Process the destination domain and terminate the command string

	MOVE B,[POINT 7,DOMAIN]	; point at domain string
	MOVX D,HSTNML		; maximum length of a host name
	CALL GETDOM		; get domain name
	 RET			; syntax error in domain
	CAIE C,.CHRAB		; closing broket?
	 RET			; no, syntax error
	SKIPE MAILBX		; mailbox required
	 SKIPN DOMAIN		; domain required
	  RET			; mailbox or domain missing
PRMDUN:	ILDB C,A		; see if line ends now
	JUMPN C,R		; it doesn't, return
	RETSKP
; Table of special characters

	BRINI.			; initialize break mask

	BRKCH. (.CHNUL,.CHSPC)	; all controls are special characters
	BRKCH. (042)		; """"
	BRKCH. (050,051)	; "(", ")"
	BRKCH. (054)		; ","
	BRKCH. (072,074)	; ":", ";", "<"
;	BRKCH. (076)		; ">" commented out because processed in code
;	BRKCH. (100)		; "@" commented out because processed in code
	BRKCH. (133)		; "["
;	BRKCH. (134)		; "\" commented out because processed in code
	BRKCH. (135)		; "]"

SPCMSK:	EXP W0.,W1.,W2.,W3.	; form table of special characters

; These tables are for quoting in the return-path

	BRINI.			; initialize break mask

	BRKCH. (.CHCNA,.CHTAB)	; CTRL/A through CTRL/I
	BRKCH. (.CHVTB,.CHFFD)	; CTRL/K, CTRL/L
	BRKCH. (.CHCNN,.CHSPC)	; CTRL/N through space
	BRKCH. (050,051)	; "(", ")"
	BRKCH. (054)		; ","
	BRKCH. (072,074)	; ":", ";", "<"
	BRKCH. (076)		; ">"
	BRKCH. (100)		; "@"
	BRKCH. (133)		; "["
	BRKCH. (135)		; "]"

QOTMSK:	EXP W0.,W1.,W2.,W3.

; If any of these characters are seen, they must be quoted with backslash

	BRINI.			; initialize break mask

	BRKCH. (.CHLFD)		; line feed
	BRKCH. (.CHCRT)		; carriage return
	BRKCH. (042)		; """"
	BRKCH. (134)		; "\"

QT1MSK:	EXP W0.,W1.,W2.,W3.
;  Here to get a domain string, source pointer in A, destination pointer in B,
; maximum number of bytes in D.  Skips if success with delimiter in C.

GETDOM: ILDB C,A		; get first byte of domain string
	CAIE C,"#"		; monolithic number?
	IFSKP.
	  IDPB C,B		; save indicator of moby number
	  SUBI D,1		; account for character
	  ILDB C,A		; get first byte of number
	  CAIL C,"0"		; is it a number?
	   CAILE C,"9"
	    RET			; must have at least one digit
	  DO.
	    IDPB C,B		; save digit
	    ILDB C,A		; get subsequent digit(s)
	    CAIL C,"0"		; is it a number?
	     CAILE C,"9"
	      EXIT.		; no, end of domain
	    SOJGE D,TOP.	; else store digit and try again 
	    RET			; string too long
	  ENDDO.
	ELSE.
	  CAIE C,"["		; dot-number?
	  IFSKP.
	    MOVX E,3		; number of dots expected in field
	    DO.
	      IDPB C,B		; save bracket or dot
	      SOJL D,R		; account for character (syn err if full)
	      ILDB C,A		; get first byte of number
	      CAIL C,"0"	; is it a number?
	       CAILE C,"9"
		RET		; must have at least one digit
	      DO.		; collect a number into the buffer
		IDPB C,B	; save digit
		ILDB C,A	; get subsequent digit(s)
		CAIL C,"0"	; is it a number?
		 CAILE C,"9"
		  EXIT.		; no, leave
		SOJGE D,TOP.	; numeric, store digit and try again 
		RET		; string too long
	      ENDDO.
	      SOJL E,ENDLP.	; if seen three dots then done
	      CAIN C,"."	; dot expected, did we see one?
	       LOOP.		; yes, store it and collect next number
	      RET		; else syntax error
	    ENDDO.
	    CAIE C,"]"		; closing bracket?
	     RET		; no, syntax error
	    IDPB C,B		; store closing bracket in string
	    SOJL D,R		; see if it makes string too long
	    ILDB C,A		; get delimiter byte for caller
	  ELSE.
	    CAIL C,"A"		; non-alphabetic?
	     CAILE C,"z"
	      RET		; first character must be alphabetic
	    CAILE C,"Z"		; further alphabetic checking
	     CAIL C,"a"
	      CAIA
	       RET		; non-alphabetic, lose
	    DO.
	      IDPB C,B		; store byte in string
	      SOJL D,R		; length check
	      ILDB C,A		; get next byte of string
	      CAIE C,"."	; dot?
	       CAIN C,"-"	; hyphen?
		LOOP.		; yes, store in string
	      CAIL C,"A"	; non-alphabetic?
	       CAILE C,"z"
	      IFSKP.
		CAILE C,"Z"	; further alphabetic checking
		 CAIL C,"a"
		  LOOP.		; character is alphabetic, store in string
	      ENDIF.
	      CAIL C,"0"	; numeric?
	       CAILE C,"9"
		EXIT.		; no, end of domain
	      LOOP.		; character is numeric, store in string
	    ENDDO.
	    LDB E,B		; get last byte in string
	    CAIE E,"."		; disallow null domain element
	     CAIN E,"-"		; domain string may not end in hyphen
	      RET		; it did, syntax error
	  ENDIF.
	ENDIF.
	SAVEAC <B>		; leave string pointing at null
	SETZ E,			; tie off string with null
	IDPB E,B
	RETSKP			; return success to caller
; Here to lookup a mailbox pointed to in A in the mailbox database.  Skips
; if mailbox found, with pointers in MBXPAG+300.

RUNMBX:	SAVEAC <A>		; don't clobber mailbox pointer
	STKVAR <MBXPTR>
	MOVEM A,MBXPTR		; save mailbox pointer
	SKIPLE MBXFRK		; see if already a mailbox fork
	IFSKP.
	  SETOM MBXFRK		; no, flag trying to get a mailbox fork
	  SETOM MBXWIN		; clear memory of cached mailbox window
	  MOVX A,GJ%OLD!GJ%SHT	; get JFN of forwarder
	  HRROI B,[ASCIZ/SYS:MMAILBOX.EXE/]
	  GTJFN%
	   ERJMP R		; not implemented if no mailbox fork
	  MOVEM A,MBXFRK	; save here temporarily
	  MOVX A,CR%CAP		; create an inferior fork
	  CFORK%
	   ERCAL FATAL
	  EXCH A,MBXFRK		; save fork handle, get JFN
	  HRL A,MBXFRK		; get prog into fork
	  GET%
	   ERCAL FATAL
	ENDIF.
	HRLZ A,MBXFRK		; page 0 of inferior
	DMOVE B,[.FHSLF,,MBXPAG/1000 ; mapped to this fork's MBXPAG
		 PM%RD!PM%WR!PM%CNT+2] ; read+write access
	PMAP%
	 ERCAL FATAL
	MOVE A,[POINT 7,MBXPAG+200] ; destination
	MOVE B,MBXPTR		; source address
	MOVX C,-USRNML		; maximum length of an address
	SOUT%
	 ERCAL FATAL
	MOVE A,MBXFRK		; get fork handle back again
	TQNN F%EXP		; need to expand?
	 SKIPA B,[4]		; no, just verify existance
	  MOVX B,3		; expansion entry
	SFRKV%			; start fork
	 ERCAL FATAL
	WFORK%			; wait for it to halt
	 ERCAL FATAL
	RFSTS%			; see if it finished ok
	 ERCAL FATAL
	HLRZ A,A
	CAIN A,.RFHLT		; halted normally?
	IFSKP.
	  SETO A,		; unmap shared pages
	  DMOVE B,[.FHSLF,,MBXPAG/1000 ; mapped to this fork's MBXPAG
		   PM%CNT+2]
	  PMAP%
	   ERCAL FATAL
	  DMOVE B,[.FHSLF,,WINPAG/1000 ; mapped to this fork's WINPAG
		   PM%CNT+2]
	  PMAP%
	   ERCAL FATAL
	  MOVE A,MBXFRK		; flush the fork
	  KFORK%
	   ERCAL FATAL
	  SETZM MBXFRK
	  RET
	ENDIF.
	SKIPG MBXPAG+177	; yes, success answer?
	 RET			; no, non-skip return
	RETSKP			; success, skip return with fork still mapped

	ENDSV.
; Output string from mailbox starting from address in A

INFOUT:	SAVEAC <A,B,C>		; preserve ACs
	STKVAR <MBXADR>
	MOVEM A,MBXADR		; save address we're going to PSOUT% for later
	LSH A,-<^D9>		; get inferior page number desired
	CAMN A,MBXWIN		; already cached?
	IFSKP.
	  MOVEM A,MBXWIN	; no, set as new mailbox window page
	  DMOVE B,[.FHSLF,,WINPAG/1000 ; map two pages to our WINPAG
		   PM%CNT!PM%RD!PM%CPY+2]
	  CAIN A,777		; guard against page 777
	   SUBI C,1		; oops, only one page then
	  HRL A,MBXFRK		; mailbox fork,,page number
	  PMAP%
	   ERCAL FATAL
	ENDIF.
	MOVX A,.PRIOU		; output to primary I/O
	MOVE B,MBXADR		; get address back
	MOVX C,<WINPAG/1000>	; page in our address space
	DPB C,[POINT 9,B,26]	; set up as new address
	HRLI B,(<POINT 7,>)	; make pointer
	CALLRET MBXOUT		; output mailbox

	ENDSV.
; Here to output mailbox with RFC822 quoting
; Accepts: A/ destination designator
;	   B/ mailbox source pointer
;	CALL MBXOUT
; Returns +1: always

MBXOUT:	SAVEAC <C,D,E,F,G>
	STKVAR <SRCPTR>
	MOVEM B,SRCPTR		; save source pointer
	TQZ F%QOT		; initially require no quoting
	MOVX B,"\"		; quote for wierd characters
	MOVE G,[POINT 7,TMPBUF] ; pointer to temporary buffer
	DO.			; copy to TMPBUF with \ insert and " need check
	  ILDB C,SRCPTR		; get character from source
	   ERCAL FATAL		; in case of page mapping lossage
	  MOVEI E,(C)		; make a copy of it to hack
	  IDIVI E,^D32		; E := word to check, F := bit to check
	  MOVNS F
	  MOVX D,1B0		; D := bit to check
	  LSH D,(F)
	  TDNE D,QOTMSK(E)	; is it a special character?
	   TQO F%QOT		; yes, note
	  TDNE D,QT1MSK(E)	; is it an wierd character?
	   IDPB B,G		; yes, put in wierd character quote
	  IDPB C,G		; now copy character
	  JUMPN C,TOP.		; continue
	ENDDO.
	MOVX B,""""
	TQNE F%QOT		; need to do atomic quoting?
	 BOUT%			; yes, insert it
	HRROI B,TMPBUF		; output buffer
	SETZ C,
	SOUT%
	MOVX B,""""
	TQNE F%QOT		; need to do atomic quoting?
	 BOUT%			; yes, insert it
	RET
; Outputs a CRLF iff it is necessary

CRLF:	SAVEAC <A,B,C>
	MOVX A,.PRIOU		; use SOUTR% for non-TTY primary I/O
	HRROI B,[ASCIZ/
/]
	SETZ C,
	SOUTR%			; this pushes the text on networks
	 ERJMP .+1
	RET

; Convert a 32-bit quantity in A from squoze to ASCII

SQZTYO:	IDIVI A,50		; divide by 50
	PUSH P,B		; save remainder, a character
	SKIPE A			; if A is now zero, unwind the stack
	 CALL SQZTYO		; call self again, reduce A
	POP P,A			; get character
	ADJBP A,[POINT 7,[ASCII/ 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ.$%/],6]
	LDB A,A			; convert squoze code to ASCII
	PBOUT%
	RET
	SUBTTL Error handling

; Common routine called to output last error code's message

ERROUT:	MOVX A,.PRIOU
	HRLOI B,.FHSLF		; dumb ERSTR%
	SETZ C,
	ERSTR%
	 JRST ERRUND		; undefined error number
	 NOP			; can't happen
	RET

ERRUND:	TMSG <Undefined error >
	MOVX A,.FHSLF		; get error number
	GETER%
	MOVX A,.PRIOU		; output it
	HRRZS B			; only right half where error code is
	MOVX C,^D8		; in octal
	NOUT%
	 ERJMP R		; ignore error here
	RET
; Various SMTP errors

BADCMD:	TMSG <500 Command unrecognized: >
	JRST DMPCMD

SYNFLD:	TMSG <500 Syntax error or field too long: >
	JRST DMPCMD

SYNERR:	TMSG <500 Syntax error in command: >
	JRST DMPCMD

NOTIMP:	TMSG <502 Command not implemented: >
	JRST DMPCMD

HLOREQ:	TMSG <503 HELO required before starting a transaction: >
	JRST DMPCMD

MAIREQ:	TMSG <503 MAIL FROM required before recipients: >
	JRST DMPCMD

RCPREQ:	TMSG <503 RCPT TO required before data: >
	JRST DMPCMD

INPROG:	TMSG <503 >
	LOAD A,F%DOP		; get current delivery option
	HRROI A,DOPTAB(A)	; output name of current delivery option
	PSOUT%
	TMSG < already in progress, must RSET first: >
	JRST DMPCMD

MISARG:	TMSG <500 Missing required argument: >
	JRST DMPCMD

BADARG: TMSG <500 Argument given when none expected: >
DMPCMD:	HRROI A,BUFFER		; output losing command
	PSOUT%
	JRST GETCMD
; Fatal errors arrive here

FATAL:	MOVEM 17,FATACS+17	; save ACs in FATACS for debugging
	MOVEI 17,FATACS		; save from 0 => FATACS
	BLT 17,FATACS+16	; ...to 16 => FATACS+16
	MOVE 17,FATACS+17	; restore AC17
	MOVX A,.PRIIN		; flush TTY input
	CFIBF%
	 ERJMP .+1
	CALL CRLF		; new line first
	TMSG <421-Fatal system error: >
	CALL ERROUT		; output last JSYS error
	TMSG <, >
	MOVE F,(P)		; get PC
	MOVE F,-2(F)		; get instruction which lost
	CALL SYMOUT		; output symbolic instruction if possible
	TMSG < at PC >
	POP P,F
	MOVEI F,-2(F)		; point PC at actual location of the JSYS
	CALL SYMOUT		; output symbolic name of the PC

; Entry point to ask for a report for non-JSYS "impossible" error

IMPERR:	CALL CRLF
	TMSG <421-This isn't expected to happen; please report this
421 >
	JRST QUIT1		; skip over 221 reply code in QUIT code
;  Clever symbol table lookup routine.  For details, read "Introduction to
; DECSYSTEM-20 Assembly Language Programming", by Ralph Gorin, published by
; Digital Press, 1981.  Called with desired value in F.

SYMOUT:	SETZB C,E		; no current program name or best symbol
	MOVE D,.JBSYM		; symbol table pointer
	HLRO A,D
	SUB D,A			; -count,,ending address +1
	DO.
	  LDB A,[POINT 4,-2(D),3] ; symbol type
	  IFN. A		; 0=prog name (uninteresting)
	    CAILE A,2		; 1=global, 2=local
	  ANSKP.
	    MOVE A,-1(D)	; value of the symbol
	    CAME A,F		; exact match?
	    IFSKP.
	      MOVE E,D		; yes, select it as best symbol
	      EXIT.
	    ENDIF.
	    CAML A,F		; smaller than value sought?
	  ANSKP.
	    SKIPE B,E		; get best one so far if there is one
	     CAML A,-1(B)	; compare to previous best
	      MOVE E,D		; current symbol is best match so far
	  ENDIF.
	  ADD D,[2000000-2]	; add 2 in the left, sub 2 in the right
	  JUMPL D,TOP.		; loop unless control count is exhausted
	ENDDO.
	IFN. E			; if a best symbol found
	  MOVE A,F		; desired value
	  SUB A,-1(E)		; less symbol's value = offset
	  CAIL A,200		; is offset small enough?
	ANSKP.
	  MOVE A,-2(E)		; symbol name
	  TXZ A,<MASKB 0,3>	; clear flags
	  CALL SQZTYO		; print symbol name
	  SUB F,-1(E)		; difference between this and symbol's value
	  JUMPE F,R		; if no offset then done
	  MOVX A,"+"		; add + to the output line
	  PBOUT%
	ENDIF.
	MOVX A,.PRIOU		; and copy numeric offset to output
	MOVE B,F		; value to output
	MOVX C,^D8
	NOUT%
	 ERJMP R
	RET
; Get TCP location.  Skips if a TCP connection

IFNDEF TCP%TV,TCP%TV==:1B11	; TVT argument supplied
IFNDEF $TFH,$TFH==:7		; TCB foreign address
IFNDEF $TLH,$TLH==:10		; TCB local address

GETTCP:	IFQN. F%NVT		; NVT server?
	  MOVX A,TCP%TV		; argument is TVT
	  HRR A,MYTTYN		; our TVT number
	  HRROI B,$TFH		; want host number
	  HRROI C,FRNHNO	; put it in FRNHNO
	  STAT%
	   ERJMP R
	  MOVX A,TCP%TV		; argument is TVT
	  HRR A,MYTTYN		; our TVT number
	  HRROI B,$TLH		; want local host address
	  HRROI C,LCLHNO	; put it in LCLHNO
	  STAT%			; get it
	   ERJMP R
	ELSE.
	  MOVX A,.PRIIN		; get foreign host from TCB
	  MOVX B,.TCRTW
	  MOVEI C,$TFH
	  TCOPR%
	   ERJMP R
	  MOVEM C,FRNHNO	; save foreign host address
	  MOVEI C,$TLH		; now get local host
	  TCOPR%
	   ERJMP R
	  MOVEM C,LCLHNO	; save local host address
	ENDIF.
	HRROI A,LCLHST		; get local host name
	SETO B,
	CALL $GTHNS
	 RET
	HRROI A,LCLHST		; remove relative domain from name
	CALL $RMREL
	MOVEM B,LCLHNC		; save canonical local host address
	CAMN B,LCLHNO		; same as local host address?
	IFSKP.
	  HRROI A,BUFFER	; ugh, gotta look at this closer
	  MOVE B,LCLHNO		; get name from connection local address
	  CALL $GTHNS
	ANSKP.
	  HRROI A,BUFFER	; remove relative domain from name
	  CALL $RMREL
	  HRROI A,LCLHST	; compare the names
	  HRROI B,BUFFER
	  STCMP%
	ANDN. A
	  TMSG <421->		; sorry, local ports not supported yet!!
	  HRROI A,BUFFER	; output host name
	  PSOUT%
	  TMSG < SMTP service isn't operational yet
421 >
	  JRST QUIT1
	ENDIF.
	MOVX A,P%TCP		; set protocol to be TCP
	STOR A,F%PRO
	RETSKP
	SUBTTL Interrupt stuff

; PSI blocks

LEVTAB:	LEV1PC			; priority level table
	LEV2PC
	LEV3PC

CHNTAB:	PHASE 0			; channel table
COFCHN:!1,,COFINT		; carrier off channel
TIMCHN:!2,,TIMINT		; timer channel
	REPEAT ^D36-.,<0>
	DEPHASE
; Set up PSIs

SETPSI:	MOVX A,.FHSLF		; set level/channel tables
	MOVE B,[LEVTAB,,CHNTAB]
	SIR%
	 ERCAL FATAL
	EIR%			; enable PSIs
	 ERCAL FATAL
	MOVX B,<1B<TIMCHN>!1B<COFCHN>> ; on these channels
	AIC%
	 ERCAL FATAL
	MOVX A,<XWD .TICRF,COFCHN> ; arm for carrier off interrupts
	ATI%
;	CALLRET SETTIM

; Initialize the timer

SETTIM:	MOVE A,[.FHSLF,,.TIMEL]	; tick the timer every 5 seconds
	MOVX B,^D5*^D1000
	MOVX C,TIMCHN
	TIMER%
	 ERCAL FATAL
	RET
; Timer interrupt

TIMINT:	DMOVEM A,IN2ACS		; save ACs
	MOVEM C,IN2ACS+2
	AOSGE TIMOUT		; has timer run out yet?
	IFSKP.
	  MOVX A,.PRIIN		; flush TTY input
	  CFIBF%
	   ERJMP .+1
	  CALL CRLF		; output CRLF
	  TMSG <421-Autologout; idle for too long
421 >
	  MOVX A,<PC%USR!QUIT1>	; dismiss to quit code
	  MOVEM A,LEV2PC
	ELSE.
	  CALL SETTIM		; reinitialize the timer
	ENDIF.
	DMOVE A,IN2ACS		; restore ACs
	MOVE C,IN2ACS+2
	DEBRK%

; Carrier-off interrupt

COFINT:	CALL HANGUP		; hang up the connection
	DEBRK%			; back out if continued
	SUBTTL Other randomness

; Literals

...VAR:!VAR			; generate variables (there shouldn't be any)
IFN .-...VAR,<.FATAL Variables illegal in this program>
...LIT:	XLIST			; save trees during LIT
	LIT			; generate literals
	LIST

	END EVECL,,EVEC		; The End