/*
  *  Copyright (C) 2002, 2003 Tomasz Kojm <zolw@konarski.edu.pl>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <pthread.h>
 #include <time.h>
 #include <signal.h>
 
 #include "cfgfile.h"
 #include "others.h"
 #include "defaults.h"
 #include "scanner.h"
 #include "server.h"
 #include "clamuko.h"
 #include "tests.h"
 
 #define THREXIT					    \
     close(ths[tharg->sid].desc);		    \
     ths[tharg->sid].active = 0;			    \
     /* this mutex is rather useless */		    \

     /* pthread_mutex_unlock(&ths[tharg->sid].mutex);   */ \

     free(tharg);				    \
     return NULL
 
 #define CMD1 "SCAN"
 #define CMD2 "RAWSCAN"
 #define CMD3 "QUIT"
 #define CMD4 "RELOAD"
 #define CMD5 "PING"
 #define CMD6 "CONTSCAN"
 #define CMD7 "VERSION"
 #define CMD8 "STREAM"
 
 #ifdef CLAMUKO
 pthread_t clamukoid;
 #endif
 
 void *threadscanner(void *arg)
 {
 	struct thrarg *tharg = (struct thrarg *) arg;
 	char buff[32769];
 	sigset_t sigset;
 	int bread, options, maxwait = CL_DEFAULT_MAXWHILEWAIT;
 
 
     /* ignore all signals */
     sigfillset(&sigset);
     pthread_sigmask(SIG_SETMASK, &sigset, NULL);
 
     if(reload) {
 	logg("*Session(%d): database reloading (waiting).\n", tharg->sid);
 	ths[tharg->sid].reload = 1;
 	while(reload && maxwait--) /* wait during reloading */
 	    sleep(1);
 
 	if(!maxwait && reload) {
 	    logg("!Database reloading failed, time exceeded. Forcing quit.\n");
 	    kill(progpid, SIGTERM);
 	}
 
 	ths[tharg->sid].reload = 0;
 	logg("*Session(%d): database reloaded.\n", tharg->sid);
     }
 
     if((bread = read(ths[tharg->sid].desc, buff, 1024)) == -1) {
 	logg("!Session(%d): read() failed.\n", tharg->sid);
 	THREXIT;
     }
 
     buff[bread] = 0;
     chomp(buff);
 
     if(!strncmp(buff, CMD1, strlen(CMD1))) { /* SCAN */
 	scan(buff + strlen(CMD1) + 1, NULL, tharg->root, tharg->limits, tharg->options, tharg->copt, ths[tharg->sid].desc, 0);
 
     } else if(!strncmp(buff, CMD2, strlen(CMD2))) { /* RAWSCAN */
 	options = tharg->options & ~CL_ARCHIVE;
 	scan(buff + strlen(CMD2) + 1, NULL, tharg->root, NULL, options, tharg->copt, ths[tharg->sid].desc, 0);
 
     } else if(!strncmp(buff, CMD3, strlen(CMD3))) { /* QUIT */
 	if(!progexit)
 	    kill(progpid, SIGTERM);
 
     } else if(!strncmp(buff, CMD4, strlen(CMD4))) { /* RELOAD */
 	mdprintf(ths[tharg->sid].desc, "RELOADING\n");
 	reload = 1;
 
     } else if(!strncmp(buff, CMD5, strlen(CMD5))) { /* PING */
 	mdprintf(ths[tharg->sid].desc, "PONG\n");
 
     } else if(!strncmp(buff, CMD6, strlen(CMD6))) { /* CONTSCAN */
 	scan(buff + strlen(CMD6) + 1, NULL, tharg->root, tharg->limits, tharg->options, tharg->copt, ths[tharg->sid].desc, 1);
 
     } else if(!strncmp(buff, CMD7, strlen(CMD7))) { /* VERSION */
 	mdprintf(ths[tharg->sid].desc, "clamd / ClamAV version "VERSION"\n");
 
     } else if(!strncmp(buff, CMD8, strlen(CMD8))) { /* STREAM */
 	scanstream(ths[tharg->sid].desc, NULL, tharg->root, tharg->limits, tharg->options, tharg->copt);
     }
 
 
     THREXIT;
 }
 
 /* this function takes care for threads, exit and various checks */
 
 void *threadwatcher(void *arg)
 {
 	struct thrwarg *thwarg = (struct thrwarg *) arg;
 	struct cfgstruct *cpt;
 	sigset_t sigset;
 	int i, j, ret, maxwait;
 	unsigned long int timer = 0;
 	unsigned int timeout, threads, virnum, selfchk;
 	short int need_wait = 0, do_loop = 0, db_problem = 0;
 	const char *dbdir;
 	struct cl_stat dbstat;
 
 
     /* ignore all signals */
     sigfillset(&sigset);
     pthread_sigmask(SIG_SETMASK, &sigset, NULL);
 
 #ifdef C_LINUX
     logg("*ThreadWatcher: Started in process %d\n", getpid());
 #endif
 
     if((cpt = cfgopt(thwarg->copt, "MaxThreads")))
 	threads = cpt->numarg;
     else
 	threads = CL_DEFAULT_MAXTHREADS;
 
     if((cpt = cfgopt(thwarg->copt, "SelfCheck")))
 	selfchk = cpt->numarg;
     else
 	selfchk = CL_DEFAULT_SELFCHECK;
 
     if(!selfchk) {
 	logg("^Self checking disabled.\n");
     } else
 	logg("Self checking every %d seconds.\n", selfchk);
 
     if((cpt = cfgopt(thwarg->copt, "ThreadTimeout")))
 	timeout = cpt->numarg;
     else
 	timeout = CL_DEFAULT_SCANTIMEOUT;
 
     if(!timeout) {
 	logg("^Timeout disabled.\n");
     } else
 	logg("Timeout set to %d seconds.\n", timeout);
 
     if((cpt = cfgopt(thwarg->copt, "DataDirectory")))
 	dbdir = cpt->strarg;
     else
 	dbdir = cl_retdbdir();
 
     memset(&dbstat, 0, sizeof(struct cl_stat));
     cl_statinidir(dbdir, &dbstat);
 
     for(i = 0; ; i++) {
 
         if(i == threads)
 	    i = 0;
 
 	/* check time */

         if(ths[i].active) /* races are harmless here (timeout is re-set) */

 	    if(time(NULL) - ths[i].start > timeout) {
 		pthread_cancel(ths[i].id);
 		mdprintf(ths[i].desc, "Session(%d): Time out ERROR\n", i);
 		close(ths[i].desc);
 		logg("Session %d stopped due to timeout.\n", i);
 		ths[i].active = 0;

 //		pthread_mutex_unlock(&ths[i].mutex);

 	    }
 
 	/* cancel all threads in case of quit */
 	if(progexit == 1) {
 #ifdef CLAMUKO
 	    /* stop clamuko */
 	    if(clamuko_running) {
 		logg("Stopping Clamuko... (id %d)\n", clamukoid);
 		pthread_kill(clamukoid, SIGUSR1);
 		/* we must wait for Dazuko unregistration */
 		maxwait = CL_DEFAULT_MAXWHILEWAIT * 5;
 		while(clamuko_running && maxwait--)
 		    usleep(200000);
 
 		if(!maxwait && clamuko_running)
 		    logg("!Critical error: Can't stop Clamuko.\n");
 	    }
 #endif
 
 	    for(j = 0; j < threads; j++)
 		if(ths[j].active) {
 		    pthread_cancel(ths[j].id);
 		    mdprintf(ths[j].desc, "Session(%d): Stopped (exiting)\n", j);
 		    close(ths[j].desc);
 		    logg("Session %d stopped (exiting).\n", j);

 //		    pthread_mutex_unlock(&ths[j].mutex);

 		}
 #ifndef C_BSD
 	    logg("*Freeing trie structure.\n");
 	    cl_freetrie(*thwarg->root);
 #endif

 	    logg("*Shutting down the main socket.\n");

 	    shutdown(thwarg->socketd, 2);

 	    logg("*Closing the main socket.\n");

 	    close(thwarg->socketd);
 	    if((cpt = cfgopt(thwarg->copt, "LocalSocket"))) {
 		if(unlink(cpt->strarg) == -1)

 		    logg("!Can't unlink the socket file %s\n", cpt->strarg);

 		else
 		    logg("Socket file removed.\n");
 	    }
 
 	    if((cpt = cfgopt(thwarg->copt, "PidFile"))) {
 		if(unlink(cpt->strarg) == -1)

 		    logg("!Can't unlink the pid file %s\n", cpt->strarg);

 		else
 		    logg("Pid file removed.\n");
 	    }
 
 	    progexit = 2;
 	    logg("*Exit level %d, ThreadWatcher termination.\n", progexit);
 	    return NULL;
 	}
 
 
 	/* do self checks */
 	if(selfchk && (db_problem || !(timer % selfchk))) {
 	    /* check the integrity of the database */
 	    if(!reload) {
 
 		if(cl_statchkdir(&dbstat) == 1) {
 		    logg("SelfCheck: Database modification detected. Forcing reload.\n");
 		    reload = 1;
 		    cl_statfree(&dbstat);
 		    cl_statinidir(dbdir, &dbstat);
 		} else
 		    logg("SelfCheck: Database status OK.\n");
 
 		if(!testsignature(*thwarg->root)) {
 		    if(db_problem) {
 			logg("!SelfCheck: Unable to repair internal structure. Exiting.\n");
 			kill(progpid, SIGTERM);
 			continue;
 		    }
 		    /* oops */
 		    logg("!SelfCheck: Unable to detect test signature, forcing database reload.\n");
 		    db_problem = 1;
 		    reload = 1;
 		} else {
 		    logg("*SelfCheck: Integrity OK\n");
 		    db_problem = 0;
 		}
 	    }
 	}
 
 	timer++;
 
 	/* reload the database(s) */
 	if(reload) {
 	    do {
 		need_wait = 0;
 		for(j = 0; j < threads; j++)
 		    if(ths[j].active) {
 			if(time(NULL) - ths[j].start > timeout) {
 			    do_loop = 1;
 			    break;
 			} else if(!ths[j].reload)
 			    need_wait = 1;
 		    }
 
 #ifdef CLAMUKO
 		if(clamuko_scanning && !clamuko_reload)
 		    need_wait = 1;
 #endif
 
 		if(need_wait)
 		    usleep(200000);
 
 		if(progexit == 1)
 		    break;
 
 	    } while(need_wait);
 
 	    if(progexit == 1) {
 		reload = 0;
 		continue;
 	    }
 
 	    if(do_loop) {
 		/* some threads must be stopped in the next iteration,
 		 * reload is still == 1
 		 */
 		do_loop = 0;
 		continue;
 	    }
 
 	    /* relase old structure */
 	    cl_freetrie(*thwarg->root);
 	    *thwarg->root = NULL;
 
 	    /* reload */
 
 	    logg("Reading databases from %s\n", dbdir);
 
 	    if((ret = cl_loaddbdir(dbdir, &*thwarg->root, &virnum))) {

 		logg("!%s\n", cl_strerror(ret));

 		kill(progpid, SIGTERM);
 		/* we stay in reload == 1, so all threads are waiting */
 		continue;
 	    }
 
 	    if(! *thwarg->root) {
 		logg("!Database initialization problem.\n");
 		kill(progpid, SIGTERM);
 	    } else {
 		cl_buildtrie(*thwarg->root);
 		/* check integrity */
 
 		logg("Database correctly reloaded (%d viruses)\n", virnum);
 	    }
 
 	    reload = 0;
 	}
 
 	sleep(1);
     }
 
     return NULL;
 }
 

 int threads;
 pthread_t watcherid;
 

 int acceptloop(int socketd, struct cl_node *root, const struct cfgstruct *copt)
 {

 	int acceptd, i, options = 0, maxwait;

 	struct cfgstruct *cpt;
 	struct thrarg *tharg;
 	struct thrwarg thwarg;
 	struct cl_limits limits;
 	pthread_attr_t thattr;

 	struct sigaction sigact, sigsegvact;

 	sigset_t sigset;
 	mode_t old_umask;
 
 #if defined(C_BIGSTACK) || defined(C_BSD)
 	size_t stacksize;
 #endif
 
 
     /* save the PID */
     if((cpt = cfgopt(copt, "PidFile"))) {
 	    FILE *fd;
 	    old_umask = umask(0006);
 	if((fd = fopen(cpt->strarg, "w")) == NULL) {
 	    logg("!Can't save PID in file %s\n", cpt->strarg);
 	} else {
 	    fprintf(fd, "%d", getpid());
 	    fclose(fd);
 	}
 	umask(old_umask);
     }
 
     logg("*Listening daemon: PID: %d\n", getpid());
 
     if((cpt = cfgopt(copt, "MaxThreads")))
 	threads = cpt->numarg;
     else
 	threads = CL_DEFAULT_MAXTHREADS;
 
     logg("Maximal number of threads: %d\n", threads);
 
     ths = (struct thrsession *) mcalloc(threads, sizeof(struct thrsession));
  
     for(i = 0; i < threads; i++)
 	pthread_mutex_init(&ths[i].mutex, NULL);
 
 
     if(cfgopt(copt, "ScanArchive") || cfgopt(copt, "ClamukoScanArchive")) {
 
 	/* set up limits */
 
 	if((cpt = cfgopt(copt, "ArchiveMaxFileSize"))) {
 	    if((limits.maxfilesize = cpt->numarg))
 		logg("Archive: Archived file size limit set to %d bytes.\n", limits.maxfilesize);
 	    else
 		logg("^Archive: File size limit protection disabled.\n");
 	} else {
 	    limits.maxfilesize = 10485760;
 	    logg("^USING HARDCODED LIMIT: Archive: Archived file size limit set to %d bytes.\n", limits.maxfilesize);
 	}
 
 	if((cpt = cfgopt(copt, "ArchiveMaxRecursion"))) {
 	    if((limits.maxreclevel = cpt->numarg))
 		logg("Archive: Recursion level limit set to %d.\n", limits.maxreclevel);
 	    else
 		logg("^Archive: Recursion level limit protection disabled.\n");
 	} else {
 	    limits.maxreclevel = 5;
 	    logg("^USING HARDCODED LIMIT: Archive: Recursion level set to %d.\n", limits.maxreclevel);
 	}
 
 	if((cpt = cfgopt(copt, "ArchiveMaxFiles"))) {
 	    if((limits.maxfiles = cpt->numarg))
 		logg("Archive: Files limit set to %d.\n", limits.maxfiles);
 	    else
 		logg("^Archive: Files limit protection disabled.\n");
 	} else {
 	    limits.maxfiles = 1000;
 	    logg("^USING HARDCODED LIMIT: Archive: Files limit set to %d.\n", limits.maxfiles);
 	}
 
 	if(cfgopt(copt, "ArchiveLimitMemoryUsage")) {
 	    limits.archivememlim = 1;
 	    logg("Archive: Limited memory usage.\n", limits.maxfiles);
 	} else
 	    limits.archivememlim = 0;
     }
 
     if(cfgopt(copt, "ScanArchive")) { 
 	logg("Archive support enabled.\n");
 	options |= CL_ARCHIVE;
     } else {
 	logg("Archive support disabled.\n");
     }
 
     if(cfgopt(copt, "ScanMail")) { 
 	logg("Mail files support enabled.\n");
 	options |= CL_MAIL;
     } else {
 	logg("Mail files support disabled.\n");
     }
 
     /* initialize important global variables */
     progexit = 0;
     progpid = 0;
     reload = 0;
 #ifdef CLAMUKO
     clamuko_scanning = 0;
     clamuko_running = 0;
 #endif
 
     pthread_attr_init(&thattr);
     pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_DETACHED);
 
     /* run clamuko */
     if(cfgopt(copt, "ClamukoScanOnLine"))
 #ifdef CLAMUKO
     {
 	tharg = (struct thrarg *) mcalloc(1, sizeof(struct thrarg));
 	tharg->copt = copt;
 	tharg->root = root;
 	tharg->limits = &limits;
 	tharg->options = options;
 	clamuko_reload = 0;
 
 	pthread_create(&clamukoid, &thattr, clamukoth, tharg);
     }
 #else
 	logg("!Clamuko is not available.\n");
 #endif
 
     /* start thread watcher */
     thwarg.socketd = socketd;
     thwarg.copt = copt;
     thwarg.root = &root;
     pthread_create(&watcherid, &thattr, threadwatcher, &thwarg);
 
     /* set up signal handling */
 
     sigfillset(&sigset);
     sigdelset(&sigset, SIGINT);
     sigdelset(&sigset, SIGTERM);

     sigdelset(&sigset, SIGSEGV);

     sigprocmask(SIG_SETMASK, &sigset, NULL);
 

     /* SIGINT, SIGTERM, SIGSEGV */

     sigact.sa_handler = sigexit;

     sigsegvact.sa_handler = sigsegv;

     sigemptyset(&sigact.sa_mask);

     sigemptyset(&sigsegvact.sa_mask);

     sigaddset(&sigact.sa_mask, SIGINT);
     sigaddset(&sigact.sa_mask, SIGTERM);

     sigaddset(&sigsegvact.sa_mask, SIGSEGV);

     sigaction(SIGINT, &sigact, NULL);
     sigaction(SIGTERM, &sigact, NULL);

     sigaction(SIGSEGV, &sigsegvact, NULL);

 
     /* we need to save program's PID, because under Linux each thread
      * has another PID, it works with other OSes as well
      */
     progpid = getpid();
 
 #if defined(C_BIGSTACK) || defined(C_BSD)
     /*
      * njh@bandsman.co.uk:
      * libclamav/scanners.c uses a *huge* buffer
      * (128K not BUFSIZ from stdio.h).
      * We need to allow for that.
      */
     pthread_attr_getstacksize(&thattr, &stacksize);

     cli_dbgmsg("set stacksize to %u\n", stacksize + BUFFSIZE + 64 * 1024);

     pthread_attr_setstacksize(&thattr, stacksize + BUFFSIZE + 64 * 1024);
 #endif
 
     while(1) {
 
 	/* find a free session */
 	for(i = 0; ; i++) {
 	    if(i == threads)
 		i = 0;
 
 	    if(!ths[i].active) {
 		/* logg("*Found free slot: %d\n", i); */
 		break;
 	    }
 	}
 
 
 	if((acceptd = accept(socketd, NULL, NULL)) == -1) {
 	    logg("!accept() failed.\n");
 	    /* exit ? */
 	    continue;
 	}
 
 
 	if(reload) { /* do not start new threads */
 	    logg("*Main thread: database reloading (waiting).\n");
 	    maxwait = CL_DEFAULT_MAXWHILEWAIT;
 	    while(reload && maxwait--)
 		sleep(1);
 
 	    if(!maxwait && reload) {
 		logg("!Database reloading failed (time exceeded). Exit forced.\n");
 		progexit = 1;
 		sleep(10);
 		exit(1);
 	    }
 
 	    logg("*Main thread: database reloaded.\n");
 	}
 
 	tharg = (struct thrarg *) mcalloc(1, sizeof(struct thrarg));
 	tharg->copt = copt;
 	tharg->sid = i;
 	tharg->root = root;
 	tharg->limits = &limits;
 	tharg->options = options;
 

 	//pthread_mutex_lock(&ths[i].mutex);

 	ths[i].desc = acceptd;
 	ths[i].reload = 0;
 	pthread_create(&ths[i].id, &thattr, threadscanner, tharg);
 	ths[i].start = time(NULL);

 	ths[i].active = 1;

     }
 }
 
 void sigexit(int sig)
 {
 	time_t currtime;
 	int maxwait = CL_DEFAULT_MAXWHILEWAIT * 5;
 
     progexit = 1;
     logg("*Signal %d caught -> exiting.\n", sig);
 
     while(progexit != 2 && maxwait--)
 	usleep(200000);
 
     if(!maxwait && progexit != 2)
 	logg("!Critical error: Cannot reach exit level 2.\n");
 
     time(&currtime);
     logg("--- Stopped at %s", ctime(&currtime));
     exit(0);
 }

 
 void sigsegv(int sig)
 {
 	int i;
 
     logg("Segmentation fault :-( Bye..\n");
 
     for(i = 0; i < threads; i++)
 	if(ths[i].active)
 	    pthread_kill(ths[i].id, 9);
 
     pthread_kill(watcherid, 9);
     exit(11); /* probably not reached at all */
 }