/*
 * iwinfo - Wireless Information Library - Linux Wireless Extension Backend
 *
 *   Copyright (C) 2009 Jo-Philipp Wich <xm@subsignal.org>
 *
 * The iwinfo library 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.
 *
 * The iwinfo library 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 the iwinfo library. If not, see http://www.gnu.org/licenses/.
 *
 * Parts of this code are derived from the Linux wireless tools, iwlib.c,
 * iwlist.c and iwconfig.c in particular.
 */

#include "iwinfo.h"
#include "iwinfo_wext.h"

#define LOG10_MAGIC	1.25892541179

static int ioctl_socket = -1;

static double wext_freq2float(const struct iw_freq *in)
{
	int		i;
	double	res = (double) in->m;
	for(i = 0; i < in->e; i++) res *= 10;
	return res;
}

static int wext_freq2mhz(const struct iw_freq *in)
{
	int i, mhz;

	if( in->e == 6 )
	{
		return in->m;
	}
	else
	{
		mhz = in->m;
		for(i = 0; i < in->e; i++)
			mhz *= 10;

		return (int)(mhz / 100000);
	}
}

int wext_dbm2mw(int in)
{
	double res = 1.0;
	int ip = in / 10;
	int fp = in % 10;
	int k;

	for(k = 0; k < ip; k++) res *= 10;
	for(k = 0; k < fp; k++) res *= LOG10_MAGIC;

	return (int)res;
}

int wext_mw2dbm(int in)
{
	double fin = (double) in;
	int res = 0;

	while(fin > 10.0)
	{
		res += 10;
		fin /= 10.0;
	}

	while(fin > 1.000001)
	{
		res += 1;
		fin /= LOG10_MAGIC;
	}

	return (int)res;
}

static int wext_ioctl(const char *ifname, int cmd, struct iwreq *wrq)
{
	/* prepare socket */
	if( ioctl_socket == -1 )
	{
		ioctl_socket = socket(AF_INET, SOCK_DGRAM, 0);
		fcntl(ioctl_socket, F_SETFD, fcntl(ioctl_socket, F_GETFD) | FD_CLOEXEC);
	}

	if( !strncmp(ifname, "mon.", 4) )
		strncpy(wrq->ifr_name, &ifname[4], IFNAMSIZ);
	else
		strncpy(wrq->ifr_name, ifname, IFNAMSIZ);

	return ioctl(ioctl_socket, cmd, wrq);
}


int wext_probe(const char *ifname)
{
	struct iwreq wrq;

	if(wext_ioctl(ifname, SIOCGIWNAME, &wrq) >= 0)
		return 1;

	return 0;
}

void wext_close(void)
{
	wext_scan_close();

	if( ioctl_socket > -1 )
		close(ioctl_socket);
}

int wext_get_mode(const char *ifname, char *buf)
{
	struct iwreq wrq;

	if(wext_ioctl(ifname, SIOCGIWMODE, &wrq) >= 0)
	{
		switch(wrq.u.mode)
		{
			case 0:
				sprintf(buf, "Auto");
				break;

			case 1:
				sprintf(buf, "Ad-Hoc");
				break;

			case 2:
				sprintf(buf, "Client");
				break;

			case 3:
				sprintf(buf, "Master");
				break;

			case 4:
				sprintf(buf, "Repeater");
				break;

			case 5:
				sprintf(buf, "Secondary");
				break;

			case 6:
				sprintf(buf, "Monitor");
				break;

			default:
				sprintf(buf, "Unknown");
		}

		return 0;
	}

	return -1;
}

int wext_get_ssid(const char *ifname, char *buf)
{
	struct iwreq wrq;

	wrq.u.essid.pointer = (caddr_t) buf;
	wrq.u.essid.length  = IW_ESSID_MAX_SIZE + 1;
	wrq.u.essid.flags   = 0;

	if(wext_ioctl(ifname, SIOCGIWESSID, &wrq) >= 0)
		return 0;

	return -1;
}

int wext_get_bssid(const char *ifname, char *buf)
{
	struct iwreq wrq;

	if(wext_ioctl(ifname, SIOCGIWAP, &wrq) >= 0)
	{
		sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
			(uint8_t)wrq.u.ap_addr.sa_data[0], (uint8_t)wrq.u.ap_addr.sa_data[1],
			(uint8_t)wrq.u.ap_addr.sa_data[2], (uint8_t)wrq.u.ap_addr.sa_data[3],
			(uint8_t)wrq.u.ap_addr.sa_data[4], (uint8_t)wrq.u.ap_addr.sa_data[5]);

		return 0;
	}

	return -1;
}

int wext_get_bitrate(const char *ifname, int *buf)
{
	struct iwreq wrq;

	if(wext_ioctl(ifname, SIOCGIWRATE, &wrq) >= 0)
	{
		*buf = (wrq.u.bitrate.value / 1000);
		return 0;
	}

	return -1;
}

int wext_get_channel(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_range range;
	double freq;
	int i;

	if(wext_ioctl(ifname, SIOCGIWFREQ, &wrq) >= 0)
	{
		if( wrq.u.freq.m >= 1000 )
		{
			freq = wext_freq2float(&wrq.u.freq);
			wrq.u.data.pointer = (caddr_t) &range;
			wrq.u.data.length  = sizeof(struct iw_range);
			wrq.u.data.flags   = 0;

			if(wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0)
			{
				for(i = 0; i < range.num_frequency; i++)
				{
					if( wext_freq2float(&range.freq[i]) == freq )
					{
						*buf = range.freq[i].i;
						return 0;
					}
				}
			}
		}
		else
		{
			*buf = wrq.u.freq.m;
			return 0;
		}
	}

	return -1;
}

int wext_get_frequency(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_range range;
	int i, channel;

	if(wext_ioctl(ifname, SIOCGIWFREQ, &wrq) >= 0)
	{
		/* We got a channel number instead ... */
		if( wrq.u.freq.m < 1000 )
		{
			channel = wrq.u.freq.m;
			wrq.u.data.pointer = (caddr_t) &range;
			wrq.u.data.length  = sizeof(struct iw_range);
			wrq.u.data.flags   = 0;

			if(wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0)
			{
				for(i = 0; i < range.num_frequency; i++)
				{
					if( range.freq[i].i == channel )
					{
						*buf = wext_freq2mhz(&range.freq[i]);
						return 0;
					}
				}
			}
		}
		else
		{
			*buf = wext_freq2mhz(&wrq.u.freq);
			return 0;
		}
	}

	return -1;
}

int wext_get_txpower(const char *ifname, int *buf)
{
	struct iwreq wrq;

	wrq.u.txpower.flags = 0;

	if(wext_ioctl(ifname, SIOCGIWTXPOW, &wrq) >= 0)
	{
		if(wrq.u.txpower.flags & IW_TXPOW_MWATT)
			*buf = wext_mw2dbm(wrq.u.txpower.value);
		else
			*buf = wrq.u.txpower.value;

		return 0;
	}

	return -1;
}

int wext_get_signal(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_statistics stats;

	wrq.u.data.pointer = (caddr_t) &stats;
	wrq.u.data.length  = sizeof(struct iw_statistics);
	wrq.u.data.flags   = 1;

	if(wext_ioctl(ifname, SIOCGIWSTATS, &wrq) >= 0)
	{
		*buf = (stats.qual.updated & IW_QUAL_DBM)
			? (stats.qual.level - 0x100) : stats.qual.level;

		return 0;
	}

	return -1;
}

int wext_get_noise(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_statistics stats;

	wrq.u.data.pointer = (caddr_t) &stats;
	wrq.u.data.length  = sizeof(struct iw_statistics);
	wrq.u.data.flags   = 1;

	if(wext_ioctl(ifname, SIOCGIWSTATS, &wrq) >= 0)
	{
		*buf = (stats.qual.updated & IW_QUAL_DBM)
			? (stats.qual.noise - 0x100) : stats.qual.noise;

		return 0;
	}

	return -1;
}

int wext_get_quality(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_statistics stats;

	wrq.u.data.pointer = (caddr_t) &stats;
	wrq.u.data.length  = sizeof(struct iw_statistics);
	wrq.u.data.flags   = 1;

	if(wext_ioctl(ifname, SIOCGIWSTATS, &wrq) >= 0)
	{
		*buf = stats.qual.qual;
		return 0;
	}

	return -1;
}

int wext_get_quality_max(const char *ifname, int *buf)
{
	struct iwreq wrq;
	struct iw_range range;

	wrq.u.data.pointer = (caddr_t) &range;
	wrq.u.data.length  = sizeof(struct iw_range);
	wrq.u.data.flags   = 0;

	if(wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0)
	{
		*buf = range.max_qual.qual;
		return 0;
	}

	return -1;
}

int wext_get_assoclist(const char *ifname, char *buf, int *len)
{
	/* Stub */
	return -1;
}

int wext_get_txpwrlist(const char *ifname, char *buf, int *len)
{
	struct iwreq wrq;
	struct iw_range range;
	struct iwinfo_txpwrlist_entry entry;
	int i;

	wrq.u.data.pointer = (caddr_t) &range;
	wrq.u.data.length  = sizeof(struct iw_range);
	wrq.u.data.flags   = 0;

	if( (wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0) &&
	    (range.num_txpower > 0) && (range.num_txpower <= IW_MAX_TXPOWER) &&
	    !(range.txpower_capa & IW_TXPOW_RELATIVE)
	) {
		for( i = 0; i < range.num_txpower; i++ )
		{
			if( range.txpower_capa & IW_TXPOW_DBM )
			{
				entry.dbm = range.txpower[i];
				entry.mw  = wext_dbm2mw(range.txpower[i]);
			}

			else if( range.txpower_capa & IW_TXPOW_MWATT )
			{
				entry.dbm = wext_mw2dbm(range.txpower[i]);
				entry.mw  = range.txpower[i];
			}

			memcpy(&buf[i*sizeof(entry)], &entry, sizeof(entry));
		}

		*len = i * sizeof(entry);
		return 0;
	}

	return -1;
}

int wext_get_freqlist(const char *ifname, char *buf, int *len)
{
	struct iwreq wrq;
	struct iw_range range;
	struct iwinfo_freqlist_entry entry;
	int i, bl;

	wrq.u.data.pointer = (caddr_t) &range;
	wrq.u.data.length  = sizeof(struct iw_range);
	wrq.u.data.flags   = 0;

	if(wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0)
	{
		bl = 0;

		for(i = 0; i < range.num_frequency; i++)
		{
			entry.mhz     = wext_freq2mhz(&range.freq[i]);
			entry.channel = range.freq[i].i;

			memcpy(&buf[bl], &entry, sizeof(struct iwinfo_freqlist_entry));
			bl += sizeof(struct iwinfo_freqlist_entry);
		}

		*len = bl;
		return 0;
	}

	return -1;
}

int wext_get_country(const char *ifname, char *buf)
{
	sprintf(buf, "00");
	return 0;
}

int wext_get_countrylist(const char *ifname, char *buf, int *len)
{
	/* Stub */
	return -1;
}

int wext_get_encryption(const char *ifname, char *buf)
{
	/* No reliable crypto info in wext */
	return -1;
}

int wext_get_mbssid_support(const char *ifname, int *buf)
{
	/* No multi bssid support atm */
	return -1;
}