/*
 *	The Unix Channel
 *
 *	by Michel Beaudouin-Lafon
 *
 *	Copyright 1990-1993
 *	Laboratoire de Recherche en Informatique (LRI)
 *
 *	Port server
 *
 *	$Id$
 *	$CurLog$
 */

#include "PortServerReq.h"
#include "PortServer.h"
#include "error.h"
#include "Multiplexer.h"
#include "Datagram.h"
#include "SignalHandler.h"
#include "ccu/List.h"
#include "ccu/RegExp.h"
#include "ccu/String.h"
#include "ccu/Time.h"

#include <stdlib.h>
#include <sys/file.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <fcntl.h>
#ifdef __osf__
extern "C" {
#endif
#include <netdb.h>
#ifdef __osf__
}
#endif

//---------------- globals
//	if SaveTime > 0, the state is saved to SaveFile
//		SaveTime seconds after a modification
//	if SaveTime < 0, saving is immediate
//	if SaveTime is 0, no save
//	if SaveFileIsFd >= 0, it is taken as output file descr instead of SaveFile
const char* SaveFile = 0;
int	SaveFileIsFd = -1;
int	SaveTime = 0;
int	Mod = 0;
int	NbEntries = 0;
bool	Trace = false;
UchMultiplexer* Mpx = 0;
const char* LoadFile;

#ifndef DEFAGENTLIB
#define DEFAGENTLIB "/usr/local/lib/agents"
#endif
char	DefLoadFile [256];

#ifndef DEFAGENTBIN
#define DEFAGENTBIN "/usr/local/lib/agents/bin"
#endif
const char*	BinDir = 0;

//---------------- constants
// if an auto-launch server has not registered for REG_TIME seconds
// and somebody inquires its address, it is killed and restarted.
#define REG_TIME	60000
#define REG_STR		"minute"

// if an auto-launch server has been run within the last ALR_TIME seconds
// and has not yet registered and somebody inquires its address,
// is is _not_ run.
#define ALR_TIME	30000
#define ALR_STR		"30 seconds"

struct Service {
	CcuString	Key;
	lword	Host;
	sword	Port;
	int	Ident;
	// auto-launch stuff
	bool	AutoLaunch;
	bool	Running;
	Millisecond	LastRun;
	Millisecond	LastRegistered;
	char*	CmdLine;	// the line
	char**	RunCmd;		// array to pointers to CmdLine (for execvp)
};

#ifndef CPLUS_BUG19
CcuListOf <Service> ServList;
#else
CcuList ServList;
#endif

//---------------- auto-launch stuff
char**
ParseConfigLine (char* line)
{
	enum WHERE { IN_SPACE, IN_WORD, IN_QUOTE };
	char quote = '\0';
	register char*	s = line;
	register char*	word = line;
	register WHERE	where = IN_SPACE;
	char* words [256];
	int nw = 0;
	
	// split a line into words
	// a word is a sequence of non blank characters,
	// or a quoted string (' or ").
	// '(', ')' and ',' are also ignored to allow for function like notation
	for (; *s; s++) {
		switch (where) {
		case IN_WORD:
			if (strchr (" \t(),", *s)) {
				*s = '\0';
				where = IN_SPACE;
				if (nw < 255)
					words [nw++] = word;
				else
					return 0;
			}
			break;
		case IN_QUOTE:
			if (*s == quote) {
				*s = '\0';
				where = IN_SPACE;
				if (nw < 255)
					words [nw++] = word;
				else
					return 0;
			}
			break;
		case IN_SPACE:
			if (*s == '\'' || *s == '\"') {
				quote = *s;
				*s = '\0';
				where = IN_QUOTE;
				word = s+1;
			} else
			if (strchr (" \t(),", *s)) {
				*s = '\0';
			} else {
				where = IN_WORD;
				word = s;
			}
			break;
		}
	}
	if (where != IN_SPACE)
		if (nw < 255)
			words [nw++] = word;
		else
			return 0;
	if (where == IN_QUOTE)
		return 0;
	
	// if no argv specified, argv[0] = executable
	if (nw == 3)
		words [nw++] = words [2];
	// expected format: key dir exec argv
	if (nw < 4)
		return 0;
	// null terminated array for execvp
	words [nw++] = 0;
	
	// return a freshly allocated array
	char** nwords = new char* [nw];
	for (int i = 0; i < nw; i++)
		nwords [i] = words [i];
	return nwords;
}

void
AutoLaunch (Service* s)
{
	// s->RunCmd [0]	service name
	// s->RunCmd [1]	directory
	// s->RunCmd [2]	executable
	// s->RunCmd [3 ... ]	argv [0 ...]

	CcuTimeStamp now;
	if (s->LastRun + ALR_TIME > now) {
//		Log ("AutoLaunch", "%s already launched in the past %s", s->RunCmd [0], ALR_STR);
		return;
	}
//	Log ("AutoLaunch", "running %s dir=%s, exec=%s", s->RunCmd[0], s->RunCmd[1], s->RunCmd[2]);
	if (! fork ()) {
		// close everything but stdio
		for (int i = 3; i < NFILE; i++)
			close (i);
		// detach from controlling terminal
		setsid ();
		// change directory. "-" is default
		const char* dir = s->RunCmd [1];
		if (strcmp (dir, "-") == 0)
			dir = BinDir;
		// change directory
		if (chdir (dir) < 0)
			SysError (ErrFatal, dir);
		// exec server
		if (execvp (s->RunCmd [2], s->RunCmd + 3) < 0)
			SysError (ErrFatal, s->RunCmd [2]);
	}
	s->LastRun = now;
}

void
LoadConfigFile ()
{
	FILE* f = fopen (LoadFile, "r");
	if (!f)
		SysError (ErrFatal, LoadFile);
	char line [2048];
	while (fgets (line, sizeof (line), f)) {
		// empty line or comment
		if (! line [0] || line [0] == '#')
			continue;
		
		// expected format: servername dir exec argv0 ...
		
		// remove trailing newline and parse
		line [strlen (line) -1] = 0;
		char* nline = new char [strlen (line) + 1];
		strcpy (nline, line);
		char** words = ParseConfigLine (nline);
		if (! words) {
			::Error (ErrWarn, "LoadConfigFile", "incorrect line ignored in file");
			delete nline;
			continue;
		}
		Service* s = new Service;
		char key [256];	// agent:audio
		sprintf (key, "agent:%s", words [0]);
		s->Key = key;
		s->Host = 0;
		s->Port = 0;
		s->Ident = 0;
		s->AutoLaunch = true;
		s->Running = false;
		s->LastRun= 0;
		s->LastRegistered = 0;
		s->CmdLine = nline;
		s->RunCmd = words;
		ServList.Append (s);
//		Log ("LoadConfigFile", "defined auto-launch server %s dir=%s exec=%s",
//			s->RunCmd [0], s->RunCmd [1], s->RunCmd [2]);
	}
	fclose (f);
}

void
KillProcesses (bool all)
{
	// kill all processes that have been autolaunched,
	// assuming that their id is their pid.
	Service* s;
#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
	while (s = *++iter) {
#else
	CcuListIter iter (ServList);
	while (s = (Service*) *++iter) {
#endif
		if ((all || s->AutoLaunch) && s->Ident) {
//			Log ("KillProcesses", "killing %s pid=%d", s->RunCmd [2], (void*) s->Ident);
			kill (s->Ident, SIGTERM);
		}
	}
}

Service*
RegisterService (const char* key, lword host, sword port, int id)
{
	Service* s = 0;

#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
	while (s = *++iter) {
#else
	CcuListIter iter (ServList);
	while (s = (Service*) *++iter) {
#endif
		if (strcmp (key, s->Key) == 0)
			break;
	}
	if (! s) {
		s = new Service;
		s->Key = key;
		s->AutoLaunch = false;
		s->LastRun = 0;
		s->CmdLine = 0;
		s->RunCmd = 0;
		ServList.Append (s);
	}
	s->Host = host;
	s->Port = port;
	s->Ident = id;
	CcuTimeStamp now;
	s->LastRegistered = now;
	s->Running = true;
	return s;
}

bool
RemoveService (const char* key, lword host, sword port, int id)
{
	Service* s;
#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
	CcuListIterOf <Service> trailing_iter (ServList);
#else
	CcuListIter iter (ServList);
	CcuListIter trailing_iter (ServList);
#endif
	while (++iter) {
#ifndef CPLUS_BUG19
		s = *iter;
#else
		s = (Service*) *iter;
#endif
		if (host == s->Host && port == s->Port && id == s->Ident && strcmp (key, s->Key) == 0) {
			if (s->AutoLaunch) {
				s->Running = false;
				s->LastRun = 0;
				s->LastRegistered = 0;
				s->Host = 0;
				s->Port = 0;
				s->Ident = 0;
			} else {
				s->Key = 0;
				delete s;
				ServList.RemoveAfter (trailing_iter);
			}
			return true;
		}
		++trailing_iter;
	}
	::Error (ErrWarn, key, "not found for remove");
	return false;
}

Service*
InquireService (const char* key)
{
	Service* s;
#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
#else
	CcuListIter iter (ServList);
#endif
	while (++iter) {
#ifndef CPLUS_BUG19
		s = *iter;
#else
		s = (Service*) *iter;
#endif

		if (strcmp (key, s->Key) != 0)
			continue;

		if (!s->AutoLaunch)
			return s;

		if (s->Running) {
			CcuTimeStamp now;
			if (s->LastRegistered + REG_TIME < now) {
//				Log ("Inquire", "%s not registered for the last %s: autolaunching it", s->RunCmd [0], REG_STR);
				if (s->Ident)
					kill (s->Ident, SIGTERM);
				s->Host = 0;
				s->Port = 0;
				s->Ident = 0;
				AutoLaunch (s);
			}
		} else
			AutoLaunch (s);
		return s;
	}
	::Error (ErrWarn, key, "not found");
	return 0;
}


int
Dump ()
{
	Service* s;
#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
#else
	CcuListIter iter (ServList);
#endif
	while (++iter) {
#ifndef CPLUS_BUG19
		s = *iter;
#else
		s = (Service*) *iter;
#endif
		printf ("<%s> 0x%lx:%d (%d)\n", (const char*) s->Key, s->Host, s->Port, s->Ident);
	}
	return 0;
}

int
DumpToFile ()
{
if (Trace) printf ("dumping\n");
	int fd = SaveFileIsFd;
	if (fd < 0 && (fd = creat (SaveFile, 0600)) < 0) {
		SysError (ErrWarn, SaveFile);
		return 0;
	}
	UchFilDes Fd (fd);
	char buf [256];
	Service* s;
#ifndef CPLUS_BUG19
	CcuListIterOf <Service> iter (ServList);
#else
	CcuListIter iter (ServList);
#endif
	while (++iter) {
#ifndef CPLUS_BUG19
		s = *iter;
#else
		s = (Service*) *iter;
#endif
		sprintf (buf, "0x%lx:%d %s\n", s->Host, s->Port, (const char*) s->Key);
		Fd.Write ((byte*) buf, strlen (buf));
	}
	Mod = 0;
	return 1;
}

//	for signal handlers
//
void
SigDump (int, int)
{
	Dump ();
}

void
SigDumpFile (int, int)
{
	DumpToFile ();
}

class RegistrationChannel : public UchDatagram {
protected:
	void	Match (const char*);
public:
		RegistrationChannel (sword);
	void	HandleRead ();
};

RegistrationChannel :: RegistrationChannel (sword port)
: UchDatagram (new UchInetAddress (ANYADDR, port), 0)
{
}

void
Modified ()
{
	if (! Mod && SaveTime > 0) {
		Mod++;
		alarm (SaveTime);
		return;
	}
	if (SaveTime < 0) {
		Mod++;
		DumpToFile ();
	}
}

void
RegistrationChannel :: HandleRead ()
{
	UchMsgBuffer buf (256);
	UchPortServerReq req;

	if (Trace) printf ("HandleRead\n");
	buf.Flush ();
	int n = Receive (buf);
	if (n <= 0) {
		SysError (ErrFatal, "Receive", EINTR);
		return;
	}

	if (! buf.ReadMsg (req)) {
		::Error (ErrWarn, "Receive", "could not read message");
		return;
	}
		
	// respond
	switch (req.Type) {
	case PortServRegister:
		if (Trace) printf ("register\n");
		RegisterService (req.Key, req.Host, req.Port, int (req.Ident));
		Modified ();
		break;
			
	case PortServRemove:
		if (Trace) printf ("remove\n");
		RemoveService (req.Key, req.Host, req.Port, int (req.Ident));
		Modified ();
		break;
				
	case PortServInquire:
		{
		if (Trace) printf ("inquire\n");
		UchPortServerReq ans;
		Service* inq = InquireService (req.Key);
		if (inq) {
			ans.Type = PortServAnswer;
			ans.Host = inq->Host;
			ans.Port = inq->Port;
		} else {
			ans.Type = PortServFail;
			ans.Host = 0;
			ans.Port = 0;
		}
		buf.Flush ();
		buf.WriteMsg (ans);
		if (Reply (buf) < 0)
			SysError (ErrWarn, "reply");
		}
		break;
			
	case PortServMatch:
		if (Trace) printf ("match\n");
		Match (req.Key);
		break;
				
	case PortServDump:
		if (Trace) printf ("dump\n");
		Dump ();
		break;
			
	case PortServQuit:
		if (Trace) printf ("quit\n");
		if (SaveTime)
			DumpToFile ();
		KillProcesses (true);
		Mpx->Close ();
		break;
			
	default:
if (Trace) printf ("unknown\n");
		::Error (ErrWarn, "Receive", "unknown request");

	}
}

void
RegistrationChannel :: Match (const char* key)
{
	UchMsgBuffer buf (256);
	UchPortServerReq ans (PortServMatch);
	int nb = 0;

	CcuRegExp re (key);
	if (re.Compile ()) {
		Service* s;
#ifndef CPLUS_BUG19
		CcuListIterOf <Service> iter (ServList);
		while (++iter) {
			s = *iter;
#else
		CcuListIter iter (ServList);
		while (++iter) {
			s = (Service*) *iter;
#endif
			if (re.Match (s->Key)) {
if (Trace) printf ("Match: %s\n", (const char*) s->Key);
				ans.Host = s->Host;
				ans.Port = s->Port;
				ans.SetKey (s->Key);
				buf.WriteMsg (ans);
				Reply (buf);
				nb++;
			}
		}
	} else
		nb = -1;
	ans.Type = PortServEndMatch;
	ans.Ident = nb;
	ans.SetKey (0);
	buf.WriteMsg (ans);
	Reply (buf);
}

//---------------- BroadcastChannel

class BroadcastChannel : public UchDatagram {
protected:
	sword	p;
	pUchAddress bcast;
	UchMsgBuffer	registerBuf;
	UchMsgBuffer	removeBuf;
	UchMsgBuffer	answerBuf;

static	lword	BroadCastAddress ();
	void	Answer ();

public:
		BroadcastChannel (sword, UchInetAddress*);
	bool SetUp ();
	void HandleRead ();
	void RegisterMe ()	{ printf ("RegisterMe: %d\n", Send (registerBuf, *bcast, true /*peek*/)); }
	void RemoveMe ()	{ Send (removeBuf, *bcast, true /*peek*/); printf ("sending remove\n"); }
};

lword
BroadcastChannel :: BroadCastAddress ()
{
// *** can't get broadcast to work on DECstation !!!
	char* bcast = getenv ("BroadcastChannel");
	unsigned int b1, b2, b3, b4;
	sscanf (bcast, "%d.%d.%d.%d", &b1, &b2, &b3, &b4);
	printf ("bacst = %d.%d.%d.%d\n", b1, b2, b3, b4);
//	return (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
	return (((b1 * 256U) + b2) * 256U + b3) * 256U + b4;
}

BroadcastChannel :: BroadcastChannel (sword port, UchInetAddress* reg_addr)
: UchDatagram (new UchInetAddress (ANYADDR, port), 0)
{
	lword broadcast = BroadCastAddress ();
	bcast = new UchInetAddress (broadcast, port);

	const char* l = getlogin ();
	if (! l)
		l = cuserid (0);
	if (! l)
		::Error (ErrFatal, "BroadcastChannel", "getlogin failed");

	/* prepare answerBuf for future requests */
	char key [32];
	sprintf (key, "BroadcastChannel:%s:", l);
	lword reg_host = reg_addr->Host ();
	sword reg_port = reg_addr->Port ();
	int pid = getpid ();
	UchPortServerReq reg (PortServRegister, reg_host, reg_port, pid, key);
	registerBuf.WriteMsg (reg);
	UchPortServerReq rem (PortServRemove, reg_host, reg_port, pid, key);
	removeBuf.WriteMsg (rem);
	UchPortServerReq ans (PortServAnswer, reg_host, reg_port, pid, key);
	answerBuf.WriteMsg (ans);
}

bool
BroadcastChannel :: SetUp ()
{
	int on = 1;
	if (! UchDatagram::Setup ())
		return false;
	if (setsockopt (FilDes (), SOL_SOCKET, SO_BROADCAST, (char*) &on, sizeof (on)) < 0)
		return false;
	return true;
}

void
BroadcastChannel :: Answer ()
{
	int res = Send (answerBuf, *bcast, true /*peek*/);
	printf ("AnswerMe: %d\n", res);
}

void
BroadcastChannel :: HandleRead ()
{
	// handle requests
	//
	UchMsgBuffer buf (256);
	UchPortServerReq req;

	buf.Flush ();
	int n = Receive (buf);
	if (n <= 0) {
		SysError (ErrFatal, "BroadcastChannel", EINTR);
		return;
	}
	if (! buf.ReadMsg (req)) {
		::Error (ErrWarn, "BroadcastChannel", "could not read message");
		return;
	}
	
	// respond
	switch (req.Type) {
	case PortServRegister:
		RegisterService (req.Key, req.Host, req.Port, int (req.Ident));
		Modified ();
		printf ("received registration %s 0x%x %d %d\n", (const char*) req.Key, req.Host, req.Port, req.Ident);
		// when somebody else registers, we send our address
		Answer ();
		break;
		
	case PortServInquire:
		printf ("received inquiry\n");
		Answer ();
		break;
		
	case PortServAnswer:
		RegisterService (req.Key, req.Host, req.Port, int (req.Ident));
		Modified ();
		printf ("received answer %s 0x%x %d %d\n", (const char*) req.Key, req.Host, req.Port, req.Ident);
		break;
		
	case PortServRemove:
		RemoveService (req.Key, req.Host, req.Port, int (req.Ident));
		Modified ();
		break;
			
	default:
		::Error (ErrWarn, "main", "unknown request");
	}
}

// main
//

sword
GetPortNumber (const char* servname, int dflt)
{
	/* first try services database */
	struct servent* service = getservbyname (servname, 0);
	if (service)
		return ntohs (service->s_port);

	/* then, environment variable */
	char* portno = getenv (servname);
	if (portno) {
		int servport = atoi (portno);
		return servport;
	}

	/* then default value (may be zero)*/
	return dflt;
}

void
Usage ()
{
	::Error (ErrUsage, "portserv", "[-t] [-s service] [-quit] [-save file [time]] [-load file]");
}

main (int argc, const char** argv)
{
	const char* servname = "portserv";
	int	running = 1;
	bool	qflag = false;
	
	ProgramName (argv [0]);
	LoadFile = getenv ("AGENTMGRCF");
	while (--argc) {
		++argv;
		if (strcmp (*argv, "-quit") == 0) {
			qflag = true;
		} else
		if (strcmp (*argv, "-t") == 0) {
			Trace = true;
		} else
		if (strcmp (*argv, "-s") == 0) {
			if (--argc < 1)
				Usage ();
			servname = *++argv;
		} else
		if (strcmp (*argv, "-save") == 0) {
			if (--argc < 1)
				Usage ();
			SaveFile = *++argv;
			if (strcmp (SaveFile, "-") == 0)
				SaveFileIsFd = 1;
			else if (strcmp (SaveFile, "--") == 0)
				SaveFileIsFd = 2;
			
			if (argc > 1 && argv [1][0] != '-') {
				SaveTime = atoi (*++argv);
				--argc;
			} else
				SaveTime = -1;
		} else if (strcmp (*argv, "-load") == 0 || strcmp (*argv, "-l") == 0) {
			if (--argc < 1)
				Usage ();
			LoadFile = *++argv;
		} else
			Usage ();
	}

	// special case: portService -quit
	// send a PortServQuit message to
	// the portserver that is running
	if (qflag) {
		if (SaveFile || LoadFile)
			::Error (ErrFatal, "-quit", "incompatible with -save or -load");
		UchPortServer ps (servname, 0);
		ps.Quit ();
		exit (0);
	}

	if (! LoadFile) {
		const char* agentlib = getenv ("AGENTLIB");
		if (!agentlib)
			agentlib = DEFAGENTLIB;
		strcpy (DefLoadFile, agentlib);
		strcat (DefLoadFile, "/agentman.cf");
		if (access (DefLoadFile, R_OK) == 0)
			LoadFile = DefLoadFile;
	}

	// load config file
	//
	if (! BinDir) {
		BinDir = getenv ("AGENTBIN");
		if (! BinDir)
			BinDir = DEFAGENTBIN;
	}
	if (LoadFile)
		LoadConfigFile ();


	
	UchMultiplexer mpx;
	Mpx = &mpx;


	// get port
	//
	sword reg_port = GetPortNumber (servname, 3003);
	if (! reg_port)
		::Error (ErrFatal, servname, "service not available");

	// open dgram socket
	//
	if (Trace) printf ("opening\n");
	RegistrationChannel reg_chan (reg_port);
	if (! reg_chan.Setup ())
		SysError (ErrFatal, "main, creating portserv");
	reg_chan.SetMode (IORead);
	mpx.Add (&reg_chan);

	// open dgram broadcast socket for communicating between port servers
	//
	sword bc_port = GetPortNumber ("superman", 0);
	BroadcastChannel* bc_chan = 0;
	if (bc_port) {
		bc_chan = new BroadcastChannel (bc_port, (UchInetAddress*) reg_chan.BoundTo ());
		if (! bc_chan->Setup ()) {
			SysError (ErrWarn, "main, creating broadcast channel");
			delete bc_chan;
			bc_chan = 0;
		} else {
			::Error (ErrLog, "main", "created broadcast channel");
			bc_chan->SetMode (IORead);
			bc_chan->RegisterMe ();
			mpx.Add (bc_chan);
		}
	}

	// auto-dump stuff
	//
	UchSignalHandler h (mpx, SigHup, SigDump);
	if (SaveTime > 0)
		new UchSignalHandler (mpx, SigAlrm, SigDumpFile);
	
	// run the multiplexer
	//
	mpx.LoopScan ();

	// when quitting, notify other agent mgrs
	//
	if (bc_chan)
		bc_chan->RemoveMe ();

	return 0;
}