Commit db0cdf5d authored by Michael Hanus 's avatar Michael Hanus
Browse files

cpns and www registry removed since it is now available in Curry packages `cpns` and `html-cgi`

parent e59277de
------------------------------------------------------------------------
--- This is the main program of the CPNS demon.
---
--- @author Michael Hanus
--- @version June 2012
------------------------------------------------------------------------
import qualified CPNS
-- Everything is implemented in the library CPNS:
main :: IO ()
main = CPNS.main
# Compile the CPNS (Curry Port Name Server) demon
# to support named ports in distributed Curry programs:
TOOL = $(CURDIR)/CPNSD
LOGFILE = "/tmp/CurryPNSD.log"
# set additional options for Profile.getProcessInfos used in CPNS logging:
ifeq ($(CURRYSYSTEM),kics2)
ADD_OPTS = :set rts -T
endif
.PHONY: all compile install clean uninstall show showlog
all: install
compile: $(TOOL)
install: compile
clean:
./stop
$(CLEANCURRY)
rm -f $(TOOL)
uninstall: clean
$(TOOL): $(LIBDIR)/CPNS.curry
$(REPL) --nocypm $(REPL_OPTS) $(ADD_OPTS) :load CPNSD :save :q
# Show the currently registered ports:
show:
$(TOOL) show
# Show the log file of the demon:
showlog:
cat $(LOGFILE)
This directory contains the scripts for CPNS,
the Curry Port Name Server, which is responsible for managing the
symbolic names assigned to the named ports on a local machine.
start: script to start the CPNS demon on the local machine
This script will be automatically called by curry2prolog.
stop: script to stop the CPNS demon (usually not used)
The implementation of the CPNS demon in Curry is contained in the
system library CPNS (since it is imported by the library Ports)
based on primitive socket operations.
#!/bin/sh
# Start the Curry Port Name Server demon, if it is not already
# started on this machine:
PIDFILE="/tmp/CurryPNSD.pid"
LOGFILE="/tmp/CurryPNSD.log"
LOCKFILE="/tmp/CurryPNSD.lock" # for startup control
CPNSBIN="`dirname "$0"`/CPNSD"
STARTSERVER=no
if test ! -f $PIDFILE ; then
STARTSERVER=yes
else
# test whether the server process is still existent:
PID=`cat $PIDFILE`
touch $PIDFILE # to avoid automatic remove if file is too old
ps -p $PID | fgrep $PID > /tmp/TESTPID$$
if test ! -s /tmp/TESTPID$$ ; then
STARTSERVER=yes
rm -f $PIDFILE
echo "CPNS demon seems to be aborted. I try to restart it..." >&2
fi
rm -f /tmp/TESTPID$$
fi
if [ $STARTSERVER = yes ] ; then
if lockfile-create --lock-name $LOCKFILE ; then
echo "Starting demon for Curry Port Name Server..." >&2
if test ! -f $LOGFILE ; then
# create log file with correct access rights:
touch $LOGFILE
chmod -f 666 $LOGFILE # make log file accessible for everybody
fi
echo "Log information in file '$LOGFILE'" >&2
echo "CPNS demon started at `date`" >> $LOGFILE
echo 1 > $PIDFILE # initialize pid file with existing process
chmod -f 666 $PIDFILE # make the pid file readable for everybody
nohup "$CPNSBIN" start >> $LOGFILE 2>&1 &
echo $! > $PIDFILE # write real cpns process into pid file
lockfile-create --lock-name $LOCKFILE # wait for lockfile deletion by CPNS demon startup
lockfile-remove --lock-name $LOCKFILE
echo "CPNS demon started." >&2
else
echo "CPNS demon seems already started by other process" >&2
echo "If this is not the case, delete file $LOCKFILE" >&2
lockfile-create --lock-name $LOCKFILE # wait for lockfile deletion by CPNS demon startup
lockfile-remove --lock-name $LOCKFILE
fi
fi
#!/bin/sh
# Terminate the Curry Port Name Server demon, if it is not already terminated:
PIDFILE="/tmp/CurryPNSD.pid"
LOCKFILE="/tmp/CurryPNSD.lock" # for startup control
CPNSBIN="`dirname $0`/CPNSD"
if test ! -f $PIDFILE ; then
rm -f $LOCKFILE
echo "CPNS demon does not seem to be started." >&2
exit
elif test ! -f "$CPNSBIN" ; then
rm -f $LOCKFILE
echo "CPNS demon does not seem to be generated." >&2
exit
else
# test whether the server process is still existent:
PID=`cat $PIDFILE`
ps -p $PID | fgrep $PID > /tmp/TESTPID$$
if test ! -s /tmp/TESTPID$$ ; then
rm -f $PIDFILE /tmp/TESTPID$$ $LOCKFILE
echo "CPNS demon seems to be already aborted." >&2
exit
fi
fi
"$CPNSBIN" stop >&2
rm -f $PIDFILE /tmp/TESTPID$$ $LOCKFILE
------------------------------------------------------------------------------
--- Library to support CGI programming in the HTML library.
--- It is only intended as an auxiliary library to implement dynamic web
--- pages according to the HTML library.
--- It contains a simple script that is installed for a dynamic
--- web page and which sends the user input to the real application
--- server implementing the application.
---
--- @author Michael Hanus
--- @version September 2012
--- @category web
------------------------------------------------------------------------------
module HtmlCgi(CgiServerMsg(..),runCgiServerCmd,
cgiServerRegistry,registerCgiServer,unregisterCgiServer,
readCgiServerMsg,noHandlerPage,submitForm)
where
import System
import Char
import NamedSocket
import CPNS(unregisterPort)
import IO
import IOExts(exclusiveIO,connectToCommand)
import Directory(doesFileExist,getCurrentDirectory)
import ReadNumeric
import ReadShowTerm
import Time
import List
--------------------------------------------------------------------------
-- Should the log messages of the server stored in a log file?
withCgiLogging = True
--------------------------------------------------------------------------
--- The messages to comunicate between the cgi script and the server program.
--- CgiSubmit env cgienv nextpage - pass the environment and show next page,
--- where env are the values of the environment variables of the web script
--- (e.g., QUERY_STRING, REMOTE_HOST, REMOTE_ADDR),
--- cgienv are the values in the current form submitted by the client,
--- and nextpage is the answer text to be shown in the next web page
--- @cons GetLoad - get info about the current load of the server process
--- @cons SketchStatus - get a sketch of the status of the server
--- @cons SketchHandlers - get a sketch of all event handlers of the server
--- @cons ShowStatus - show the status of the server with all event handlers
--- @cons CleanServer - clean up the server (with possible termination)
--- @cons StopCgiServer - stop the server
data CgiServerMsg = CgiSubmit [(String,String)] [(String,String)]
| GetLoad
| SketchStatus
| SketchHandlers
| ShowStatus
| CleanServer
| StopCgiServer
--- Reads a line from a handle and check whether it is a syntactically
--- correct cgi server message.
readCgiServerMsg :: Handle -> IO (Maybe CgiServerMsg)
readCgiServerMsg handle = do
line <- hGetLine handle
case readsQTerm line of
[(msg,rem)] -> return (if all isSpace rem then Just msg else Nothing)
_ -> return Nothing
--------------------------------------------------------------------------
-- Main program to start a cgi script. It reads arguments and starts a small
-- script to forward the arguments to a cgi server process.
--
-- Optional script arguments:
-- "-servertimeout n": The timeout period for the cgi server in milliseconds.
-- If the cgi server process does not receive any request
-- during this period, it will be terminated.
-- The default value is defined in the library HTML.
--
-- "-loadbalance <t>": specifies kind of load balancing (see makecurrycgi)
-- Current possible values for <t>:
-- "no|standard|multiple"
submitForm = do
args <- getArgs
let (serverargs,lb,rargs) = stripServerArgs "" NoBalance args
case rargs of
[url,cgikey,serverprog] -> cgiScript url serverargs lb
(cgikey2portname cgikey) serverprog
[portname] -> cgiInteractiveScript portname -- for interactive execution
_ -> putStrLn $ "ERROR: cgi script called with illegal arguments!"
where
stripServerArgs serverargs load args = case args of
("-servertimeout":tos:rargs) ->
stripServerArgs (" -servertimeout "++tos) load rargs
("-multipleservers":rargs) -> stripServerArgs serverargs Multiple rargs
("-loadbalance":lbt:rargs) ->
stripServerArgs serverargs
(if lbt=="no" then NoBalance else
if lbt=="multiple" then Multiple else Standard) rargs
_ -> (serverargs,load,args)
-- load balance types:
data LoadBalance = NoBalance | Standard | Multiple
deriving Eq
--- Executes a specific command for a cgi server.
runCgiServerCmd :: String -> CgiServerMsg -> IO ()
runCgiServerCmd portname cmd = case cmd of
StopCgiServer -> do
putStrLn $ "Trying to stop server at port " ++ portname ++ "..."
h <- trySendScriptServerMessage portname StopCgiServer
hClose h
unregisterPort portname
CleanServer -> do
putStrLn $ "Trying to clean server at port " ++ portname ++ "..."
h <- trySendScriptServerMessage portname CleanServer
hClose h
GetLoad -> do
-- for upward compatibility with previous implementations:
h <- trySendScriptServerMessage portname GetLoad
cs <- hGetContents h
if length cs < 7
then do h' <- trySendScriptServerMessage portname SketchStatus
copyOutputAndClose h'
putChar '\n'
else putStrLn cs
ShowStatus -> do
h <- trySendScriptServerMessage portname ShowStatus
copyOutputAndClose h
SketchStatus -> do
h <- trySendScriptServerMessage portname SketchStatus
copyOutputAndClose h
SketchHandlers -> do
-- for upward compatibility with previous implementations:
lh <- trySendScriptServerMessage portname GetLoad
cs <- hGetContents lh
if length cs < 7
then do h <- trySendScriptServerMessage portname SketchHandlers
copyOutputAndClose h
else do h <- trySendScriptServerMessage portname SketchStatus
copyOutputAndClose h
_ -> error "HtmlCgi.runCgiServerCmd: called with illegal command!"
--- Translates a cgi progname and key into a name for a port:
cgikey2portname cgikey =
concatMap (\c->if isAlphaNum c then [c] else []) cgikey
-- Forward user inputs for interactive execution of cgi scripts:
cgiInteractiveScript :: String -> IO ()
cgiInteractiveScript portname = do
cgiServerEnvVals <- mapIO getEnviron cgiServerEnvVars
let cgiServerEnv = zip cgiServerEnvVars cgiServerEnvVals
formEnv <- getFormVariables
catch (sendToServerAndPrintOrFail cgiServerEnv formEnv)
(putStrLn . errorPage)
where
sendToServerAndPrintOrFail cgiEnviron newcenv = do
h <- trySendScriptServerMessage portname (CgiSubmit cgiEnviron newcenv)
copyOutputAndClose h
errorPage e =
"Content-type: text/html\n\n" ++
"<html>\n<head><title>Server Error</title></head>\n" ++
"<body>\n<h1>Server Error</h1>\n" ++ showError e ++ "</body>\n</html>"
-- Forward user inputs to cgi server process:
cgiScript :: String -> String -> LoadBalance -> String -> String -> IO ()
cgiScript url serverargs loadbalance portname serverprog = do
cgiServerEnvVals <- mapIO getEnviron cgiServerEnvVars
let cgiServerEnv = zip cgiServerEnvVars cgiServerEnvVals
let urlparam = head cgiServerEnvVals
formEnv <- getFormVariables
if null formEnv
then do -- call to initial script
scriptKey <- if loadbalance==Multiple then getFreshKey
else return ""
catch (submitToServerOrStart url serverargs loadbalance portname
scriptKey serverprog cgiServerEnv)
(\_ -> putStrLn (noHandlerPage url urlparam))
else do -- call to continuation script
let scriptKey = maybe "" id (lookup "SCRIPTKEY" formEnv)
cgiEnviron = ("SCRIPTKEY",scriptKey) : cgiServerEnv
newcenv = filter (\e -> fst e /= "SCRIPTKEY") formEnv
catch (sendToServerAndPrintOrFail scriptKey cgiEnviron newcenv)
(\_ -> putStrLn (noHandlerPage url urlparam))
where
sendToServerAndPrintOrFail scriptKey cgiEnviron newcenv = do
h <- trySendScriptServerMessage (portname++scriptKey)
(CgiSubmit cgiEnviron newcenv)
eof <- hIsEOF h
if eof then error "Html.cgiScript: unexpected EOF failure"
else copyOutputAndClose h
-- get a new unique key for a script:
getFreshKey :: IO String
getFreshKey = do
ctime <- getClockTime
pid <- getPID
return (show (clockTimeToInt ctime) ++ '_' : show pid)
------------------------------------------------------------------------
-- Generate HTML string of a web page with "no handler" error:
noHandlerPage :: String -> String -> String
noHandlerPage cgiurl urlparam =
"Content-type: text/html\n\n" ++
"<html>\n<head><title>Server Error</title></head>\n" ++
"<body>\n<h1>Error: no submission handler</h1>\n" ++
"<p>Your request cannot be processed due to one of the following reasons:</p>\n" ++
"<ul>\n" ++
"<li>You have not submitted the web form for a long period (timeout).</li>\n"++
"<li>You have used the 'back' button of your browser and submitted\n"++
" the web form again (which should not be done in order to avoid the\n"++
" double submission of data).</li>\n" ++
"<li>The web server has been rebooted.</li>\n" ++
"</ul>\n" ++
"<p>In any case, <a href=\"" ++
(cgiurl ++ if null urlparam then "" else '?':urlparam) ++
"\">please click here to restart.</a></p>\n" ++
"</body>\n</html>"
------------------------------------------------------------------------
--- The values of the environment variables of the web script server
--- that are transmitted to the application program.
--- Currently, it contains only a selection of all reasonable variables
--- but this list can be easily extended.
cgiServerEnvVars =
["PATH_INFO","QUERY_STRING","HTTP_COOKIE","REMOTE_HOST","REMOTE_ADDR",
"REQUEST_METHOD","SCRIPT_NAME","SERVER_NAME","SERVER_PORT"]
-- The timeout (in msec) of the script server.
-- If the port of the application server is not available within the timeout
-- period, we assume that the application server does not exist and we start
-- a new one.
scriptServerTimeOut = 1000
-- send a message to the script server and return the connection handle,
-- or fail:
trySendScriptServerMessage :: String -> a -> IO Handle
trySendScriptServerMessage portname msg =
connectToSocketRepeat scriptServerTimeOut done 0 (portname++"@localhost") >>=
maybe failed (\h -> hPutStrLn h (showQTerm msg) >> hFlush h >> return h)
-- submit an initial web page request to a server or restart it:
submitToServerOrStart url serverargs loadbalance pname scriptkey
serverprog cgiServerEnv =
connectToSocketRepeat scriptServerTimeOut done 0 completeportname >>=
maybe (execAndCopyOutput servercmd)
(\h ->
if loadbalance/=Standard
then cgiSubmit h
else do
isbusy <- getLoadOfServer h
if isbusy
then submitToOtherServer
else connectToSocketRepeat scriptServerTimeOut done 0
completeportname >>=
maybe (execAndCopyOutput servercmd) cgiSubmit )
where
completeportname = pname++scriptkey++"@localhost"
cmd = serverprog ++ serverargs ++ " -port \"" ++ pname
++ "\" -scriptkey \"" ++ scriptkey ++ "\""
errout = if withCgiLogging then " 2>> "++url++".log" else ""
servercmd = cmd++errout++" &"
cgiSubmit h = do
let cgiEnviron = ("SCRIPTKEY",scriptkey) : cgiServerEnv
hPutStrLn h (showQTerm (CgiSubmit cgiEnviron []))
hFlush h
copyOutputAndClose h
getLoadOfServer h = do
hPutStrLn h (showQTerm GetLoad)
hFlush h
loadanswer <- hGetLine h
hClose h
return (take 4 loadanswer == "busy")
submitToOtherServer = do
other <- findOtherReadyServer
otherscriptkey <- maybe (getFreshKey >>= \k -> return (scriptkey++k))
return
other
submitToServerOrStart url serverargs loadbalance pname
otherscriptkey serverprog cgiServerEnv
-- try to return the scriptkey of another ready server
findOtherReadyServer = do
regs <- readCgiServerRegistry
let otherports = map (\ (_,_,p)->p)
(filter (\ (_,prog,_) -> serverprog==prog) regs)
findOtherReadyServerInPorts otherports
findOtherReadyServerInPorts [] = return Nothing
findOtherReadyServerInPorts (p:ps) = do
let (ppname,pscriptkey) = splitAt (length pname) p
if ppname==pname -- it is a port for the current script version
then connectToSocketRepeat scriptServerTimeOut done 0 (p++"@localhost") >>=
maybe (findOtherReadyServerInPorts ps) -- no connection
(\h -> do
isbusy <- getLoadOfServer h
if isbusy
then findOtherReadyServerInPorts ps
else return (Just pscriptkey) )
else findOtherReadyServerInPorts ps
-- Execute a command and copy its output to stdout.
-- This is necessary since some web servers do not transfer
-- the output of cgi programs if the process is not terminated.
execAndCopyOutput :: String -> IO ()
execAndCopyOutput cmd = connectToCommand cmd >>= copyOutputAndClose
-- Copy input from the given handle to stdout and close it after eof.
copyOutputAndClose :: Handle -> IO ()
copyOutputAndClose h = do
clen <- copyUntilEmptyLine 0
if clen==0 then copyOutputUntilEOF else copyOutputLength clen
hClose h
where
copyUntilEmptyLine clen = do
l <- hGetLine h
putStrLn l
let clen' = if "Content-Length:" `isPrefixOf` l
then maybe clen fst (readNat (drop 15 l))
else clen
if null l then return clen' else copyUntilEmptyLine clen'
copyOutputUntilEOF = do
eof <- hIsEOF h
if eof
then done
else hGetLine h >>= putStrLn >> copyOutputUntilEOF
copyOutputLength n = do
if n>0 then hGetChar h >>= putChar >> copyOutputLength (n-1)
else done
-- Puts a line to stderr:
putErrLn s = hPutStrLn stderr s >> hFlush stderr
------------------------------------------------------------------------------
--- Gets the list of variable/value pairs sent from the browser for the
--- current CGI script.
--- Used for the implementation of the HTML event handlers.
getFormVariables :: IO [(String,String)]
getFormVariables = do
clen <- getEnviron "CONTENT_LENGTH"
cont <- getNChar (maybe 0 fst (readNat clen))
return (includeCoordinates (parseCgiEnv cont))
-- translate a string of cgi environment bindings into list of binding pairs:
parseCgiEnv :: String -> [(String,String)]
parseCgiEnv s | s == "" = []
| otherwise = map ufield2field
(map (\(n,v)->(n,utf2latin (urlencoded2string v)))
(map (splitChar '=') (split (=='&') s)))
where
ufield2field (n,v) = if take 7 n == "UFIELD_"
then (tail n, utf2latin (urlencoded2string v))
else (n,v)
-- split a string at particular character:
splitChar c xs = let (ys,zs) = break (==c) xs
in if zs==[] then (ys,zs) else (ys,tail zs)
-- split a string at all positions of a particular character:
split p xs =
let (ys,zs) = break p xs
in if zs==[] then [ys]
else ys : split p (tail zs)
--- Translates urlencoded string into equivalent ASCII string.
urlencoded2string :: String -> String
urlencoded2string [] = []
urlencoded2string (c:cs)
| c == '+' = ' ' : urlencoded2string cs
| c == '%' = chr (maybe 0 fst (readHex (take 2 cs)))
: urlencoded2string (drop 2 cs)
| otherwise = c : urlencoded2string cs
--- Transforms a string with UTF-8 umlauts into a string with latin1 umlauts.
utf2latin :: String -> String
utf2latin [] = []
utf2latin [c] = [c]
utf2latin (c1:c2:cs)
| ord c1 == 195 = chr (ord c2 + 64) : utf2latin cs
| otherwise = c1 : utf2latin (c2:cs)
includeCoordinates :: [(String,String)] -> [(String,String)]
includeCoordinates [] = []
includeCoordinates ((tag,val):cenv)
= case break (=='.') tag of
(_,[]) -> (tag,val):includeCoordinates cenv
(event,['.','x']) -> ("x",val):(event,val):includeCoordinates cenv
(_,['.','y']) -> ("y",val):includeCoordinates cenv
_ -> error "includeCoordinates: unexpected . in url parameter"
-- get n chars from stdin:
getNChar n = if n<=0 then return ""
else do c <- getChar
cs <- getNChar (n-1)
return (c:cs)
------------------------------------------------------------------------------
--- The name of the file to register all cgi servers.
cgiServerRegistry = "/tmp/CURRY_CGI_REGISTRY"
-- Register a new cgi server process (for global management of all such
-- processes on a host):
registerCgiServer :: String -> String -> IO ()
registerCgiServer eurl epname =
-- we want to be sure that everything is evaluated before locking:
(register $## eurl) $## epname
where
register url pname = exclusiveIO (cgiServerRegistry++".lock") $ do
exreg <- doesFileExist cgiServerRegistry
if exreg then done else do
writeFile cgiServerRegistry ""
system ("chmod 666 "++cgiServerRegistry) >> done
pid <- getPID
wd <- getCurrentDirectory
appendFile cgiServerRegistry (show (pid,wd++"/"++url++".server",pname)++"\n")
-- Unregister the previously registered cgi server process:
-- processes on a host):
unregisterCgiServer :: String -> IO ()
unregisterCgiServer epname =
-- we want to be sure that everything is evaluated before locking:
unregister $## epname
where
unregister pname = exclusiveIO (cgiServerRegistry++".lock") $ do
exreg <- doesFileExist cgiServerRegistry
if not exreg then done else do
mypid <- getPID
regs <- readCgiServerRegistry
let uregs = filter (\ (pid,_,port) -> mypid/=pid || pname/=port) regs
writeFile cgiServerRegistry (concatMap (\reg->show reg++"\n") uregs)
-- Return the current server registry:
readCgiServerRegistry :: IO [(Int,String,String)]
readCgiServerRegistry = do
regs <- readQTermListFile cgiServerRegistry
seq (length regs) done -- just to be sure that everything is immediately read
return regs
---------------------------------------------------------------------------
# Compile programs for managing cgi server processes
# (used by HTML libraries):
REGISTRY = $(CURDIR)/Registry
SUBMITFORM = $(CURDIR)/SubmitForm
.PHONY: all compile install clean uninstall
.PHONY: cleanServers show showload sketch showall stop kill
all: install
install: compile
compile:
$(MAKE) $(SUBMITFORM)
$(MAKE) $(REGISTRY)
clean:
$(CLEANCURRY)
rm -f $(SUBMITFORM) $(REGISTRY)
uninstall: clean
$(SUBMITFORM): SubmitForm.curry HtmlCgi.curry \
$(LIBDIR)/NamedSocket.curry $(LIBDIR)/CPNS.curry
$(REPL) --nocypm $(REPL_OPTS) :load SubmitForm :save :q
$(REGISTRY): Registry.curry HtmlCgi.curry
$(REPL) --nocypm $(REPL_OPTS) :load Registry :save :q
cleanServers:
$(REGISTRY) clean
show:
$(REGISTRY) show
showload:
$(REGISTRY) showload
sketch:
$(REGISTRY) sketch