deb-mbse/mbtask/taskibc.c

/*****************************************************************************
 *
 * $Id$
 * Purpose ...............: mbtask - Internet BBS Chat (but it looks like...)
 *
 *****************************************************************************
 * Copyright (C) 1997-2005
 *   
 * Michiel Broek		FIDO:	2:280/2802
 * Beekmansbos 10
 * 1971 BV IJmuiden
 * the Netherlands
 *
 * This file is part of MBSE BBS.
 *
 * This BBS 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, or (at your option) any
 * later version.
 *
 * MBSE BBS 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 MBSE BBS; see the file COPYING.  If not, write to the Free
 * Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *****************************************************************************/

#include "../config.h"
#include "../lib/mbselib.h"
#include "taskstat.h"
#include "taskibc.h"



#ifdef  USE_EXPERIMENT

int		    ibc_run = FALSE;	    /* Thread running		*/
extern int	    T_Shutdown;		    /* Program shutdown		*/
extern int	    internet;		    /* Internet status		*/
time_t		    scfg_time = (time_t)0;  /* Servers config time	*/
ncs_list	    *ncsl = NULL;	    /* Neighbours list		*/
int		    ls;			    /* Listen socket		*/
struct sockaddr_in  myaddr_in;		    /* Listen socket address	*/
struct sockaddr_in  clientaddr_in;	    /* Remote socket address	*/
int		    changed = FALSE;	    /* Databases changed	*/


typedef enum {NCS_INIT, NCS_CALL, NCS_WAITPWD, NCS_CONNECT, NCS_HANGUP, NCS_FAIL, NCS_DEAD} NCSTYPE;


static char *ncsstate[] = {
    (char *)"init", (char *)"call", (char *)"waitpwd", (char *)"connect", 
    (char *)"hangup", (char *)"fail", (char *)"dead"
};


/*
 * Add a port to the portlist
 */
void fill_ncslist(ncs_list **, char *, char *, char *);
void fill_ncslist(ncs_list **fdp, char *server, char *myname, char *passwd)
{
    ncs_list *tmp, *ta;

    tmp = (ncs_list *)malloc(sizeof(ncs_list));
    memset(tmp, 0, sizeof(tmp));
    tmp->next = NULL;
    strncpy(tmp->server, server, 63);
    strncpy(tmp->myname, myname, 63);
    strncpy(tmp->passwd, passwd, 15);
    tmp->state = NCS_INIT;
    tmp->action = time(NULL);
    tmp->last = (time_t)0;
    tmp->version = 0;
    tmp->remove = FALSE;
    tmp->socket = -1;
    tmp->token = 0;
    tmp->gotpass = FALSE;
    tmp->gotserver = FALSE;

    if (*fdp == NULL) {
	*fdp = tmp;
    } else {
	for (ta = *fdp; ta; ta = ta->next)
	if (ta->next == NULL) {
	    ta->next = (ncs_list *)tmp;
	    break;
	}
    }
}



void dump_ncslist(void);
void dump_ncslist(void)
{   
    ncs_list	*tmp;
    time_t	now;

    if (!changed)
	return;

    now = time(NULL);
    Syslog('r', "Server                         State   Del Pwd Srv Next action");
    Syslog('r', "------------------------------ ------- --- --- --- -----------");
    
    for (tmp = ncsl; tmp; tmp = tmp->next) {
	Syslog('r', "%-30s %-7s %s %s %s %d", tmp->server, ncsstate[tmp->state], 
		tmp->remove ? "yes":"no ", tmp->gotpass ? "yes":"no ", 
		tmp->gotserver ? "yes":"no ", (int)tmp->action - (int)now);
    }
    changed = FALSE;
}



/*
 * Send a message to all servers
 */
void send_all(char *msg)
{
}



/*
 * Send message to a server
 */
int send_msg(int s, struct sockaddr_in servaddr, char *host, char *msg)
{
    Syslog('r', "> %s: %s", host, printable(msg, 0));

    if (sendto(s, msg, strlen(msg), 0, (struct sockaddr *)&servaddr, sizeof(struct sockaddr_in)) == -1) {
	Syslog('r', "$Can't send message");
	return -1;
    }
    return 0;
}



void check_servers(void)
{
    char	*errmsg, scfgfn[PATH_MAX], buf[512];
    FILE	*fp;
    ncs_list	*tnsl;
    int		inlist;
    time_t	now;
    int         a1, a2, a3, a4;
    struct servent      *se;
    struct hostent      *he;

    sprintf(scfgfn, "%s/etc/ibcsrv.data", getenv("MBSE_ROOT"));
    
    /*
     * Check if configuration is changed, if so then apply the changes.
     */
    if (file_time(scfgfn) != scfg_time) {
	Syslog('r', "%s filetime changed, rereading");

	if ((fp = fopen(scfgfn, "r"))) {
	    fread(&ibcsrvhdr, sizeof(ibcsrvhdr), 1, fp);

	    while (fread(&ibcsrv, ibcsrvhdr.recsize, 1, fp)) {
		Syslog('r', "IBC server \"%s\", Active %s", ibcsrv.server, ibcsrv.Active ?"Yes":"No");
		if (ibcsrv.Active) {
		    inlist = FALSE;
		    for (tnsl = ncsl; tnsl; tnsl = tnsl->next) {
			if (strcmp(tnsl->server, ibcsrv.server) == 0) {
			    inlist = TRUE;
			}
		    }
		    if (!inlist ) {
			Syslog('r', "  not in neighbour list, add");
			fill_ncslist(&ncsl, ibcsrv.server, ibcsrv.myname, ibcsrv.passwd);
			changed = TRUE;
			Syslog('+', "Added Internet BBS Chatserver %s", ibcsrv.server);
		    }
		}
	    }

	    /*
	     * Now check for neighbours to delete
	     */
	    for (tnsl = ncsl; tnsl; tnsl = tnsl->next) {
		fseek(fp, ibcsrvhdr.hdrsize, SEEK_SET);
		inlist = FALSE;
		Syslog('r', "IBC server \"%s\"", ibcsrv.server);

		while (fread(&ibcsrv, ibcsrvhdr.recsize, 1, fp)) {
		    if ((strcmp(tnsl->server, ibcsrv.server) == 0) && ibcsrv.Active) {
			inlist = TRUE;
		    }
		}
		if (!inlist) {
		    Syslog('r', "  not in configuration, remove");
		    tnsl->remove = TRUE;
		    tnsl->action = time(NULL);
		    changed = TRUE;
		}
	    }
	    fclose(fp);
	}

	scfg_time = file_time(scfgfn);
    }

    dump_ncslist();

    /*
     * Check if we need to make state changes
     */
    now = time(NULL);
    for (tnsl = ncsl; tnsl; tnsl = tnsl->next) {
	if (((int)tnsl->action - (int)now) <= 0) {
	    switch (tnsl->state) {
		case NCS_INIT:	    Syslog('r', "%s init", tnsl->server);
				    changed = TRUE;

				    /*
				     * If Internet is available, setup the connection.
				     */
				    if (internet) {
					/*
					 * Get IP address for the hostname, set default next action
					 * to 60 seconds.
					 */
					tnsl->action = now + (time_t)60;
					memset(&tnsl->servaddr_in, 0, sizeof(struct sockaddr_in));
					se = getservbyname("fido", "udp");
					tnsl->servaddr_in.sin_family = AF_INET;
					tnsl->servaddr_in.sin_port = se->s_port;
					
					if (sscanf(tnsl->server,"%d.%d.%d.%d",&a1,&a2,&a3,&a4) == 4)
					    tnsl->servaddr_in.sin_addr.s_addr = inet_addr(tnsl->server);
					else if ((he = gethostbyname(tnsl->server)))
					    memcpy(&tnsl->servaddr_in.sin_addr, he->h_addr, he->h_length);
					else {
					    switch (h_errno) {
						case HOST_NOT_FOUND:    errmsg = (char *)"Authoritative: Host not found"; break;
						case TRY_AGAIN:         errmsg = (char *)"Non-Authoritive: Host not found"; break;
						case NO_RECOVERY:       errmsg = (char *)"Non recoverable errors"; break;
						default:                errmsg = (char *)"Unknown error"; break;
					    }
					    Syslog('+', "No IP address for %s: %s", tnsl->server, errmsg);
					    tnsl->state = NCS_FAIL;
					    break;
					}
					
					tnsl->socket = socket(AF_INET, SOCK_DGRAM, 0);
					if (tnsl->socket == -1) {
					    Syslog('+', "$Can't create socket for %s", tnsl->server);
					    tnsl->state = NCS_FAIL;
					    break;
					}

					Syslog('r', "socket %d", tnsl->socket);
					tnsl->token = gettoken();
					tnsl->state = NCS_CALL;
					tnsl->action = now + (time_t)1;
				    } else {
					tnsl->action = now + (time_t)10;
				    }
				    break;
				    
		case NCS_CALL:	    Syslog('r', "%s call", tnsl->server);
				    sprintf(buf, "PASS %s 0000 IBC| %s\r\n", tnsl->passwd, tnsl->compress ? "Z":"");
				    send_msg(tnsl->socket, tnsl->servaddr_in, tnsl->server, buf);
				    sprintf(buf, "SERVER %s 0 %ld mbsebbs v%s\r\n",  tnsl->myname, tnsl->token, VERSION);
				    send_msg(tnsl->socket, tnsl->servaddr_in, tnsl->server, buf);
				    tnsl->action = now + (time_t)50;
				    tnsl->state = NCS_WAITPWD;
				    changed = TRUE;
				    break;
				    
		case NCS_WAITPWD:   /*
				     * This state can be left by before the timeout is reached
				     * by a reply from the remote if the connection is accepted.
				     */
				    Syslog('r', "%s waitpwd", tnsl->server);
				    tnsl->state = NCS_CALL;
				    break;
	    }
	}
    }

    dump_ncslist();
}



void command_pass(char *hostname, char *parameters)
{
    ncs_list	*tnsl;

}


void receiver(struct servent  *se)
{
    struct pollfd   pfd;
    struct hostent  *hp;
    int             rc, len, inlist;
    socklen_t       sl;
    ncs_list	    *tnsl;
    char            buf[1024], resp[512], *hostname, *prefix, *command, *parameters;

    pfd.fd = ls;
    pfd.events = POLLIN;
    pfd.revents = 0;

    if ((rc = poll(&pfd, 1, 1000) < 0)) {
	Syslog('r', "$poll/select failed");
	return;
    } 
	
    if (pfd.revents & POLLIN || pfd.revents & POLLERR || pfd.revents & POLLHUP || pfd.revents & POLLNVAL) {
	sl = sizeof(myaddr_in);
	memset(&clientaddr_in, 0, sizeof(struct sockaddr_in));
        memset(&buf, 0, sizeof(buf));
        if ((len = recvfrom(ls, &buf, sizeof(buf)-1, 0,(struct sockaddr *)&clientaddr_in, &sl)) != -1) {
	    hp = gethostbyaddr((char *)&clientaddr_in.sin_addr, sizeof(struct in_addr), clientaddr_in.sin_family);
	    if (hp == NULL)
	        hostname = inet_ntoa(clientaddr_in.sin_addr);
	    else
	        hostname = hp->h_name;

	    if ((buf[strlen(buf) -2] != '\r') && (buf[strlen(buf) -1] != '\n')) {
	        Syslog('r', "Message not terminated with CR-LF, dropped");
	        return;
	    }

	    inlist = FALSE;
	    for (tnsl = ncsl; tnsl; tnsl = tnsl->next) {
		if (strcmp(tnsl->server, hostname) == 0) {
		    inlist = TRUE;
		    break;
		}
	    }
	    if (!inlist) {
		Syslog('!', "Message from unknown host (%s), dropped", hostname);
		return;
	    }

	    buf[strlen(buf) -2] = '\0';
	    Syslog('r', "< %s: \"%s\"", hostname, printable(buf, 0));

	    /*
	     * Parse message
	     */
	    if (buf[0] == ':') {
		prefix = strtok(buf, " ");
		command = strtok(NULL, " \0");
		parameters = strtok(NULL, "\0");
	    } else {
		prefix = NULL;
		command = strtok(buf, " \0");
		parameters = strtok(NULL, "\0");
	    }
	    Syslog('r', "prefix     \"%s\"", printable(prefix, 0));
	    Syslog('r', "command    \"%s\"", printable(command, 0));
	    Syslog('r', "parameters \"%s\"", printable(parameters, 0));

	    if (! strcmp(command, (char *)"PASS") && parameters) {
		command_pass(hostname, parameters);
	    } else if (tnsl->state == NCS_CONNECT) {
		/*
		 * Only if connected we send a error response
		 */
		sprintf(resp, "421 %s: Unknown command\r\n", command);
		send_msg(tnsl->socket, tnsl->servaddr_in, tnsl->server, resp);
	    }
	} else {
	    Syslog('r', "recvfrom returned len=%d", len);
	}
    }
}



/*
 * IBC thread
 */
void *ibc_thread(void *dummy)
{
    struct servent  *se;

    Syslog('+', "Starting IBC thread");

    if ((se = getservbyname("fido", "udp")) == NULL) {
	Syslog('!', "No fido udp entry in /etc/services, cannot start Internet BBS Chat");
	goto exit;
    }

    myaddr_in.sin_family = AF_INET;
    myaddr_in.sin_addr.s_addr = INADDR_ANY;
    myaddr_in.sin_port = se->s_port;
    Syslog('+', "Listen on %s, port %d\n", inet_ntoa(myaddr_in.sin_addr), ntohs(myaddr_in.sin_port));

    ls = socket(AF_INET, SOCK_DGRAM, 0);
    if (ls == -1) {
	Syslog('!', "$Can't create socket");
	goto exit;
    }

    if (bind(ls, (struct sockaddr *)&myaddr_in, sizeof(struct sockaddr_in)) == -1) {
	Syslog('!', "$Can't bind socket");
	goto exit;
    }

    ibc_run = TRUE;

    while (! T_Shutdown) {

	/*
	 * First check Shutdown requested
	 */
	if (T_Shutdown) {
	}
	
	/*
	 * Check neighbour servers state
	 */
	check_servers();

	/*
	 * Get any incoming messages
	 */
	receiver(se);
    }

exit:
    ibc_run = FALSE;
    Syslog('+', "IBC thread stopped");
    pthread_exit(NULL);
}


#endif