/*
  pand - Bluetooth PAN daemon for BlueZ
  Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2, as
  published by the Free Software Foundation.

  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

/*
 * $Id$
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>
#include <getopt.h>

#include <sys/socket.h>
#include <sys/poll.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/l2cap.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/bnep.h>

#include "pand.h"

static uint16_t role = BNEP_SVC_PANU;   // Local role (ie service)
static uint16_t service = BNEP_SVC_NAP; // Remote service

static int  detach = 1;
static int  persist;
static int  use_sdp = 1;
static int  use_cache;
static int  encrypt;
static int  master;
static int  search_duration = 10;

static struct {
	int      valid;
	char     dst[40];
	bdaddr_t bdaddr;
} cache;

static char netdev[16] = "bnep%d";

static bdaddr_t src_addr = *BDADDR_ANY;
static int src_dev = -1;

volatile int terminate;

enum {
	NONE,
	SHOW,
	LISTEN,
	CONNECT,
	KILL
} modes;

static void run_devup(char *dev, char *dst)
{
	char *argv[4], prog[40];

	sprintf(prog, "%s/%s", PAND_CONFIG_DIR, PAND_DEVUP_CMD);

	if (access(prog, R_OK | X_OK))
		return;

	if (fork())
		return;

	argv[0] = prog;
	argv[1] = dev;
	argv[2] = dst;
	argv[3] = NULL;
	execv(prog, argv);
	exit(1);
}

static int do_listen(void)
{
	struct l2cap_options l2o;
	struct sockaddr_l2 l2a;
	int sk, olen, lm;

	if (use_sdp)
		bnep_sdp_register(role);

	// Create L2CAP socket and bind it to PSM BNEP
	sk = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
	if (sk < 0) {
		syslog(LOG_ERR, "Cannot create L2CAP socket. %s(%d)",
				strerror(errno), errno);
		return -1;
	}

	l2a.l2_family = AF_BLUETOOTH;
	l2a.l2_psm    = htobs(BNEP_PSM);
	l2a.l2_bdaddr = src_addr;

	if (bind(sk, (struct sockaddr *) &l2a, sizeof(l2a))) {
		syslog(LOG_ERR, "Bind failed. %s(%d)", strerror(errno), errno);
		return -1;
	}

	/* Setup L2CAP options according to BNEP spec */
	if (getsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &l2o, &olen) < 0) {
		syslog(LOG_ERR, "Failed to get L2CAP options. %s(%d)",
				strerror(errno), errno);
		return -1;
	}

	l2o.imtu = l2o.omtu = BNEP_MTU;
	if (setsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &l2o, sizeof(l2o)) < 0) {
		syslog(LOG_ERR, "Failed to set L2CAP options. %s(%d)",
				strerror(errno), errno);
		return -1;
	}

	/* Set link mode */
	lm = 0;
	if (master)
		lm |= L2CAP_LM_MASTER;

	if (encrypt)
		lm |= L2CAP_LM_ENCRYPT;

	if (lm && setsockopt(sk, SOL_L2CAP, L2CAP_LM, &lm, sizeof(lm)) < 0) {
		syslog(LOG_ERR, "Failed to set link mode. %s(%d)", strerror(errno), errno);
		return -1;
	}

	listen(sk, 10);

	while (!terminate) {
		int alen = sizeof(l2a);
		int nsk;
		nsk = accept(sk, (struct sockaddr *) &l2a, &alen);
		if (nsk < 0) {
			syslog(LOG_ERR, "Accept failed. %s(%d)", strerror(errno), errno);
			continue;
		}

		switch (fork()) {
		case 0:
			break;
		case -1:
			syslog(LOG_ERR, "Fork failed. %s(%d)", strerror(errno), errno);
		default:
			close(nsk);
			continue;
		}

		if (!bnep_accept_connection(nsk, role, netdev)) {
			char str[40];
			ba2str(&l2a.l2_bdaddr, str);

			syslog(LOG_INFO, "New connection from %s %s", str, netdev);

			run_devup(netdev, str);
		} else {
			syslog(LOG_ERR, "Connection failed. %s(%d)",
					strerror(errno), errno);
		}

		close(nsk);
		exit(0);
	}

	if (use_sdp)
		bnep_sdp_unregister();
	return 0;
}

/* Wait for disconnect or error condition on the socket */
static int w4_hup(int sk)
{
	struct pollfd pf;
	int n;

	while (!terminate) {
		pf.fd = sk;
		pf.events = POLLERR | POLLHUP;
		n = poll(&pf, 1, -1);
		if (n < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			syslog(LOG_ERR, "Poll failed. %s(%d)",
					strerror(errno), errno);
			return 1;
		}

		if (n) {
			int err = 0, olen = sizeof(err);
			getsockopt(sk, SOL_SOCKET, SO_ERROR, &err, &olen);
			syslog(LOG_INFO, "%s disconnected%s%s", netdev,
				err ? " : " : "", err ? strerror(err) : "");

			close(sk);
			return 0;
		}
	}
	return 0;
}

/* Connect and initiate BNEP session
 * Returns:
 *   -1 - critical error (exit persist mode)
 *   1  - non critical error
 *   0  - success
 */
static int create_connection(char *dst, bdaddr_t *bdaddr)
{
	struct l2cap_options l2o;
	struct sockaddr_l2 l2a;
	int sk, olen, r = 0;

	syslog(LOG_INFO, "Connecting to %s", dst);

	sk = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
	if (sk < 0) {
		syslog(LOG_ERR, "Cannot create L2CAP socket. %s(%d)",
				strerror(errno), errno);
		return -1;
	}

	/* Setup L2CAP options according to BNEP spec */
	getsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &l2o, &olen);
	l2o.imtu = l2o.omtu = BNEP_MTU;
	setsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &l2o, sizeof(l2o));

	l2a.l2_family = AF_BLUETOOTH;

	/* Set local address */
	l2a.l2_psm = 0;
	l2a.l2_bdaddr = src_addr;

	if (bind(sk, (struct sockaddr *) &l2a, sizeof(l2a)))
		syslog(LOG_ERR, "Bind failed. %s(%d)", 
				strerror(errno), errno);

	l2a.l2_psm = htobs(BNEP_PSM);
	l2a.l2_bdaddr = *bdaddr;

	if (!connect(sk, (struct sockaddr *) &l2a, sizeof(l2a)) && 
			!bnep_create_connection(sk, role, service, netdev)) {

		syslog(LOG_INFO, "%s connected", netdev);

		run_devup(netdev, dst);

		if (persist)
			w4_hup(sk);

		r = 0;
	} else {
		syslog(LOG_ERR, "Connect to %s failed. %s(%d)",
				dst, strerror(errno), errno);
		r = 1;
	}

	close(sk);

	if (use_cache) {
		if (!r) {
			/* Succesesful connection, validate cache */
			strcpy(cache.dst, dst);
			bacpy(&cache.bdaddr, bdaddr);
			cache.valid = use_cache;
		} else
			cache.valid--;
	}
	
	return r;
}

/* Search and connect
 * Returns:
 *   -1 - critical error (exit persist mode)
 *   1  - non critical error
 *   0  - success
 */
static int do_connect(void)
{
	inquiry_info *ii;
	int reconnect = 0;
	int i, n, r = 0;

	do {
		if (reconnect)
			sleep(persist);
		reconnect = 1;

		if (cache.valid > 0) {
			/* Use cached bdaddr */
			r = create_connection(cache.dst, &cache.bdaddr);
			if (r < 0) {
				terminate = 1;
				break;
			}
			continue;
		}

		syslog(LOG_INFO, "Inquiring");

		/* FIXME: Should we use non general LAP here ? */

		ii = NULL;
		n  = hci_inquiry(src_dev, search_duration, 10, NULL, &ii, 0);
		if (n < 0) {
			syslog(LOG_ERR, "Inquiry failed. %s(%d)", strerror(errno), errno);
			continue;
		}

		for (i = 0; i < n; i++) {
			char dst[40];
			ba2str(&ii[i].bdaddr, dst);

			if (use_sdp) {
				syslog(LOG_INFO, "Searching for %s on %s", 
						bnep_svc2str(service), dst);

				if (bnep_sdp_search(&src_addr, &ii[i].bdaddr, service) <= 0)
					continue;
			}

			r = create_connection(dst, &ii[i].bdaddr);
			if (r < 0) {
				terminate = 1;
				break;
			}
		}
		free(ii);
	} while (!terminate && persist);

	return r;
}

static void do_show(void)
{
	bnep_show_connections();
}

static void do_kill(char *dst)
{
	if (dst)
		bnep_kill_connection((void *) strtoba(dst));
	else
		bnep_kill_all_connections();
}

void sig_hup(int sig)
{
	return;
}

void sig_term(int sig)
{
	terminate = 1;
}

static struct option main_lopts[] = {
	{ "help",     0, 0, 'h' },
	{ "listen",   0, 0, 's' },
	{ "connect",  1, 0, 'c' },
	{ "search",   2, 0, 'Q' },
	{ "kill",     1, 0, 'k' },
	{ "killall",  0, 0, 'K' },
	{ "role",     1, 0, 'r' },
	{ "service",  1, 0, 'd' },
	{ "device",   1, 0, 'i' },
	{ "source",   1, 0, 'S' },
	{ "nosdp",    0, 0, 'D' },
	{ "list",     0, 0, 'l' },
	{ "show",     0, 0, 'l' },
	{ "nodetach", 0, 0, 'n' },
	{ "persist",  2, 0, 'p' },
	{ "encrypt",  0, 0, 'E' },
	{ "master",   0, 0, 'M' },
	{ "cache",    0, 0, 'C' },
	{ 0, 0, 0, 0 }
};

static char main_sopts[] = "hsc:k:Kr:i:S:lnp::DQ::EMC::";

static char main_help[] = 
	"PAN daemon version " VERSION " \n"
	"Usage:\n"
	"\tpand <options>\n"
	"Options:\n"
	"\t--show --list -l          Show active PAN connections\n"
	"\t--listen -s               Listen for PAN connections\n"
	"\t--connect -c <bdaddr>     Create PAN connection\n"
	"\t--search -Q[duration]     Search and connect\n"
	"\t--kill -k <bdaddr>        Kill PAN connection\n"
	"\t--killall -K              Kill all PAN connections\n"
	"\t--role -r <role>          Local PAN role (PANU, NAP, GN)\n"
	"\t--service -d <role>       Remote PAN service (PANU, NAP, GN)\n"
	"\t--device -i <name>        Network interface name\n"
	"\t--source -S <bdaddr>      Source bdaddr\n"
	"\t--nosdp -D                Disable SDP\n"
	"\t--encrypt -E              Enable encryption\n"
	"\t--master -M               Become the master of a piconet\n"
	"\t--nodetach -n             Do not become a daemon\n"
	"\t--persist -p[interval]    Persist mode\n"
	"\t--cache -C[valid]         Cache addresses\n";

int main(int argc, char **argv)
{
	char *dst = NULL, *src = NULL;
	struct sigaction sa;
	int mode = NONE;
	int opt;

	while ((opt=getopt_long(argc, argv, main_sopts, main_lopts, NULL)) != -1) {
		switch(opt) {
		case 'l':
			mode = SHOW;
			detach = 0;
			break;

		case 's':
			mode = LISTEN;
			break;

		case 'c':
			mode = CONNECT;
			dst  = strdup(optarg);
			break;

		case 'Q':
			mode = CONNECT;
			dst  = NULL;
			if (optarg)
				search_duration = atoi(optarg);
			break;

		case 'k':
			mode = KILL;
			detach = 0;
			dst  = strdup(optarg);
			break;
	
		case 'K':
			mode = KILL;
			detach = 0;
			dst  = NULL;
			break;
			
		case 'S':
			src = strdup(optarg);
			break;
	
		case 'r':
			bnep_str2svc(optarg, &role);
			break;

		case 'd':
			bnep_str2svc(optarg, &service);
			break;

		case 'D':
			use_sdp = 0;
			break;

		case 'E':
			encrypt = 1;
			break;

		case 'M':
			master = 1;
			break;

		case 'i':
			strcpy(netdev, optarg);
			break;
		
		case 'n':
			detach = 0;
			break;

		case 'p':
			if (optarg)
				persist = atoi(optarg);
			else
				persist = 5;
			break;

		case 'C':
			if (optarg)
				use_cache = atoi(optarg);
			else
				use_cache = 2;
			break;
			
		case 'h':
		default:
			printf(main_help);
			exit(0);
		}
	}

	argc -= optind;
	argv += optind;
	optind = 0;

	if (bnep_init())
		return -1;

	/* Check non daemon modes first */
	switch (mode) {
	case SHOW:
		do_show();
		return 0;

	case KILL:
		do_kill(dst);
		return 0;
	
	case NONE:
		printf(main_help);
		return 0;
	}

	/* Initialize signals */
	memset(&sa, 0, sizeof(sa));
	sa.sa_flags   = SA_NOCLDSTOP;
	sa.sa_handler = SIG_IGN;
	sigaction(SIGCHLD, &sa, NULL);
	sigaction(SIGPIPE, &sa, NULL);

	sa.sa_handler = sig_hup;
	sigaction(SIGHUP, &sa, NULL);

	sa.sa_handler = sig_term;
	sigaction(SIGTERM, &sa, NULL);
	sigaction(SIGINT,  &sa, NULL);

	if (detach) {
		if (fork()) exit(0);

		/* Direct stdin,stdout,stderr to '/dev/null' */
		{
			int fd = open("/dev/null", O_RDWR);
			dup2(fd, 0); dup2(fd, 1); dup2(fd, 2);
			close(fd);
		}

		setsid();
		chdir("/");
	}

	openlog("pand", LOG_PID | LOG_NDELAY | LOG_PERROR, LOG_DAEMON);
	syslog(LOG_INFO, "PAN daemon ver %s", VERSION);

	if (src) {
		src_dev = hci_devid(src);
		if (src_dev < 0 || hci_devba(src_dev, &src_addr) < 0) {
			syslog(LOG_ERR, "Invalid source. %s(%d)", strerror(errno), errno);
			return -1;
		}
	}

	if (dst) {
		/* Disable cache invalidation */
		use_cache = 0;

		strncpy(cache.dst, dst, sizeof(cache.dst) - 1);
		str2ba(dst, &cache.bdaddr);
		cache.valid = 1;
	}
	
	switch (mode) {
	case CONNECT:
		do_connect();
		break;

	case LISTEN:
		do_listen();
		break;
	}

	return 0;
}