cproc¶
CPROC - Interactive Terminal Command Processor ../sdsys/GPL.BP/CPROC
Many of the system commands (also known as Verbs) are nothing more than basic programs (however there are “internal” commands handled directly by CPROC, see list below).
These commands can be:
Commands can be entered from a “terminal” and have an associated “VOC” file entry: VOC type “V” for Verb or locally catalogued subroutine.
Field2 |
Field3 |
Description |
|---|---|---|
CA |
name |
Catalogued verb |
CS |
path |
Locally catalogued function runfile path |
IN |
n |
Internal verb number n (see below for list of Internal Verbs) |
OS |
text |
Operating system command |
Field4 = dispatch info (@option) for all verbs |
||
Field5 = security subroutine (optional) |
||
Commands processed as part of a Paragraph (VOC type “PA” which in turn is made up of a list of commands)
User Name:
Setting up the user name.
The user name is stored in 3 different places: USER_ENTRY table. structure PROCESS at both process.username and in the syscom common block (process.syscom).
The linux user name is picked up in vm code kernal.c function init_kernel().
The init_kernel() function uses (!GetUserName((char*)(my_uptr->username), &m)) to place the user name in the USER_ENTRY table,
then uses strcpy(process.username, (char*)(my_uptr->username)) to place in structure PROCESS at process.username.
Finally CPROC has the line logname = kernel(K$USERNAME, 0) which places user name in syscom common (at postion 14).
(kernel(K$USERNAME, 0) returns the user name found in process.username, see op_kernel in op_kernel.c)
The @logname (and @user) @ functions retrieve the user name from syscom logname (the 14 entry in process.syscom) see op_ldsys() in op_loads.c
Special note about running with root privileges (sudo sd):
All administrative tasks within SD must be performed from account SDSYS.
In order to log into account SDSYS, SD must be started with root privileges (sudo sd).
Since running with root privileges allows the process to perform system wide tasks,
it is recommended to only run at this level when necessary. When SD is run as root,
the command processor (CPROC) will drop the effective user id (euid) of the process to that of user SDYS.
Administrative commands that require root privileges are defined with in the CPROC code in dynamic array
privileged_commands.
privileged_commands = ''
privileged_commands<-1> = "$CREATEA" ;*"CREATE.ACCOUNT"
privileged_commands<-1> = "$DELACC" ;*"DELETE.ACCOUNT"
privileged_commands<-1> = "$MODIFYA" ;*"MODIFY.ACCOUNT"
When commands defined in privileged_commands are executed, the euid of the process is restore to that of root,
the command is executed, and the euid is dropped back down to that of SDYS.
pseudocode:
If this is the first time through CPROC (kernel(K$CPROC.LEVEL,0) ==0):
initialize various things in the SYSCOM common block
execute $LOGIN program
If this is a telnet or serial connection prompt for user name and password, validate with op_login (kernel.c) which calls
login_user(un,pw) found in linuxio.c
if not valid login abort.cproc
if logging in root (sudo sd) call EUID_SET to drop euid /egid to that of sdsys
If phantom session:
setup COMO file record for this session
set phantom command options
endif
Execute MASTER.LOGIN paragraph
Execute LOGIN paragraph
else * Stacked CPROC, abort or LOGTO RESET
get.voc.parser.rec (ln428)
Inc CPROC stack depth ( kernel(K$CPROC.LEVEL,kernel(K$CPROC.LEVEL,0)+1) )
endif (ln520)
if EXECUTE command (flag setting in Object Header defined in header.h both basic and c versions) Not exactly sure how that gets set - needs investigating
xeq.command is command name (stored in $syscom common block not sure how it gets there!, look at kernel((K$CPROC.LEVEL,..) see what it does
executed via creating "local" voc record: voc.rec = 'PA':@fm:xeq.command)
calls execute.paragraph which ends up calling proc.para.sentence and eventually end up at execute.commad: (ln1406)
goto abort.cproc (ln557) see below
if is phantom process (ln562)
Execute the phantom command
gosub proc.sentence
goto abort.cproc
else
this is a single command invocation of SD (user typed sd "LIST VOC" on os command line window).
gosub proc.sentence
goto abort.cproc
end
**
* Main command processor loop
**
connected.port:
Loop
gosub reset.environment
gosub set.links ;* Unsnap subroutine links
unload.object ;* Unload inactive object code
debug.off ;* Ensure debugger turned off
debug.initialised = @false ;* Force restart of debugger
* Fetch new command
loop
gosub get.command.line which returns at.command
until at.command # ""
repeat
new.sentence = at.command
gosub proc.sentence
repeat - loop repeats until some sort of abort or exit
proc.para.sentence:
proc.sentence:
proc.command: note: these are all entry points that eventually end up at execute.command
parse sentence and look for VOC record for command
execute.commad:
CASE VOC is TYPE:
User Defined VOC type
Process Command (CALL @handler) with handler defined in $VOC.PARSER record
VERB voc.entry.type[1,1] = "V"
Verbs
Type "CA" - call catalogued command stored in Field3 via @call
For privileged_commands perform EUID_RESTORE @call followed by EUID_SET
Type "CS" - call Locally catalogued function via @call
Type "IN" - internal CPROC command (see internal verbs list below)
Type "OS" - OS command - gosub os.command
Type "EX" - Executable - gosub run.exe <-- need to look more into these two
PROC voc.entry.type[1,2] = 'PQ' - old PROC PROCESSOR for R83 compatibility
REMOTE voc.entry.type[1,1] = 'R'
SENTENCE voc.entry.type[1,1] = "S"
PARAGRAPH voc.entry.type[1,2] = "PA"
MENU voc.entry.type[1,1] = "M"
KEYWORD voc.entry.type[1,1] = "K"
PRIVATE CATALOG ENTRY (BASIC PROGRAM which is executed via creating local voc record: voc.rec = 'V':@fm:'CA':@fm:verb) and jumping back up to execute.commad (ln1406)
GLOBAL CATALOG ENTRY (BASIC PROGRAM which is executed via creating local voc record: voc.rec = 'V':@fm:'CA':@fm:verb) and jumping back up to execute.commad (ln1406)
CASE 1 - Error Message - not in VOC
exit.command:
If CPROC entry
Dec CPROC level
i = kernel(K$CPROC.LEVEL,0)
delete.common '$':i ;* Delete unnamed common
i = kernel(K$CPROC.LEVEL, i - 1)
Return
abort.cproc:
dec command level with code:
i = kernel(K$CPROC.LEVEL,0) - 1
void kernel(K$CPROC.LEVEL,i) ;* Decrement command level
terminate.cproc: return to terminate.cproc
From Documentation:
Sometimes a subroutine needs to return to the calling routine but it is not known how many internal subroutines may be active.
ERROR.LABEL: RETURN TO ERROR.LABEL
This will cause all internal subroutines to return to the RETURN statement and then return to the calling program
Internal Commands:
Verb type = "IN" ;* Internal CPROC command processed by corresponding CPROC internal subroutines:
on voc.rec<3> gosub int.quit, ;* 1 Quit (or OFF, see VOC entry for OFF)
int.clr, ;* 2 Clear screen
int.display, ;* 3 Display text at terminal
int.run, ;* 4 Run program
int.abort, ;* 5 ABORT
int.clearselect, ;* 6 Clear select list
int.date, ;* 7 DATE
int.time, ;* 8 TIME
int.break, ;* 9 BREAK
int.bell, ;* 10 BELL
int.go, ;* 11 GO
int.status, ;* 12 STATUS
int.set.date, ;* 13 SET.DATE
int.help, ;* 14 HELP
int.update.account, ;* 15 UPDATE.ACCOUNT
int.who, ;* 16 WHO
int.logto, ;* 17 LOGTO
int.if, ;* 18 IF
int.cleardata, ;* 19 CLEARDATA
int.clearprompts, ;* 20 CLEARPROMPTS
int.clear.stack, ;* 21 CLEAR.STACK
int.echo, ;* 22 ECHO
int.hush, ;* 23 HUSH
int.sleep, ;* 24 SLEEP
int.clearinput, ;* 25 CLEARINPUT
int.clear.locks, ;* 26 CLEAR.LOCKS
int.lock, ;* 27 LOCK
int.logout, ;* 28 LOGOUT
int.debug, ;* 29 DEBUG
int.stop, ;* 30 STOP
int.report.src, ;* 31 REPORT.SRC
int.pterm, ;* 32 PTERM
int.date.format, ;* 33 DATE.FORMAT
int.set, ;* 34 SET
int.umask, ;* 35 UMASK
int.pdump, ;* 36 PDUMP
int.pause, ;* 37 PAUSE
int.clear.abort, ;* 38 CLEAR.ABORT
int.set.exit.status, ;* 39 SET.EXIT.STATUS
int.report.style, ;* 40 REPORT.STYLE
int.logmsg ;* 41 LOGMSG
End of CPROC description