zd_mac.c

zd1211无线网卡驱动源代码

	if (flags & R2M_11A) {
		if (ZD_CS_TYPE(modulation) == ZD_CS_OFDM)
			modulation |= ZD_CS_OFDM_MODE_11A;
	}
	return modulation;
}

static void cs_set_modulation(struct zd_mac *mac, struct zd_ctrlset *cs,
	                      struct ieee80211_hdr_4addr *hdr)
{
	struct ieee80211softmac_device *softmac = ieee80211_priv(mac->netdev);
	u16 ftype = WLAN_FC_GET_TYPE(le16_to_cpu(hdr->frame_ctl));
	u8 rate, cs_rate;
	int is_mgt = (ftype == IEEE80211_FTYPE_MGMT) != 0;

	/* FIXME: 802.11a? short preamble? */
	rate = ieee80211softmac_suggest_txrate(softmac,
		is_multicast_ether_addr(hdr->addr1), is_mgt);

	cs_rate = rate_to_cs_rate(rate);
	cs->modulation = cs_rate_to_modulation(cs_rate, 0);
}

static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs,
	                   struct ieee80211_hdr_4addr *header)
{
	unsigned int tx_length = le16_to_cpu(cs->tx_length);
	u16 fctl = le16_to_cpu(header->frame_ctl);
	u16 ftype = WLAN_FC_GET_TYPE(fctl);
	u16 stype = WLAN_FC_GET_STYPE(fctl);

	/*
	 * CONTROL:
	 * - start at 0x00
	 * - if fragment 0, enable bit 0
	 * - if backoff needed, enable bit 0
	 * - if burst (backoff not needed) disable bit 0
	 * - if multicast, enable bit 1
	 * - if PS-POLL frame, enable bit 2
	 * - if in INDEPENDENT_BSS mode and zd1205_DestPowerSave, then enable
	 *   bit 4 (FIXME: wtf)
	 * - if frag_len > RTS threshold, set bit 5 as long if it isnt
	 *   multicast or mgt
	 * - if bit 5 is set, and we are in OFDM mode, unset bit 5 and set bit
	 *   7
	 */

	cs->control = 0;

	/* First fragment */
	if (WLAN_GET_SEQ_FRAG(le16_to_cpu(header->seq_ctl)) == 0)
		cs->control |= ZD_CS_NEED_RANDOM_BACKOFF;

	/* Multicast */
	if (is_multicast_ether_addr(header->addr1))
		cs->control |= ZD_CS_MULTICAST;

	/* PS-POLL */
	if (stype == IEEE80211_STYPE_PSPOLL)
		cs->control |= ZD_CS_PS_POLL_FRAME;

	if (!is_multicast_ether_addr(header->addr1) &&
	    ftype != IEEE80211_FTYPE_MGMT &&
	    tx_length > zd_netdev_ieee80211(mac->netdev)->rts)
	{
		/* FIXME: check the logic */
		if (ZD_CS_TYPE(cs->modulation) == ZD_CS_OFDM) {
			/* 802.11g */
			cs->control |= ZD_CS_SELF_CTS;
		} else { /* 802.11b */
			cs->control |= ZD_CS_RTS;
		}
	}

	/* FIXME: Management frame? */
}

static int fill_ctrlset(struct zd_mac *mac,
	                struct ieee80211_txb *txb,
			int frag_num)
{
	int r;
	struct sk_buff *skb = txb->fragments[frag_num];
	struct ieee80211_hdr_4addr *hdr =
		(struct ieee80211_hdr_4addr *) skb->data;
	unsigned int frag_len = skb->len + IEEE80211_FCS_LEN;
	unsigned int next_frag_len;
	unsigned int packet_length;
	struct zd_ctrlset *cs = (struct zd_ctrlset *)
		skb_push(skb, sizeof(struct zd_ctrlset));

	if (frag_num+1  < txb->nr_frags) {
		next_frag_len = txb->fragments[frag_num+1]->len +
			        IEEE80211_FCS_LEN;
	} else {
		next_frag_len = 0;
	}
	ZD_ASSERT(frag_len <= 0xffff);
	ZD_ASSERT(next_frag_len <= 0xffff);

	cs_set_modulation(mac, cs, hdr);

	cs->tx_length = cpu_to_le16(frag_len);

	cs_set_control(mac, cs, hdr);

	packet_length = frag_len + sizeof(struct zd_ctrlset) + 10;
	ZD_ASSERT(packet_length <= 0xffff);
	/* ZD1211B: Computing the length difference this way, gives us
	 * flexibility to compute the packet length.
	 */
	cs->packet_length = cpu_to_le16(mac->chip.is_zd1211b ?
			packet_length - frag_len : packet_length);

	/*
	 * CURRENT LENGTH:
	 * - transmit frame length in microseconds
	 * - seems to be derived from frame length
	 * - see Cal_Us_Service() in zdinlinef.h
	 * - if macp->bTxBurstEnable is enabled, then multiply by 4
	 *  - bTxBurstEnable is never set in the vendor driver
	 *
	 * SERVICE:
	 * - "for PLCP configuration"
	 * - always 0 except in some situations at 802.11b 11M
	 * - see line 53 of zdinlinef.h
	 */
	cs->service = 0;
	r = zd_calc_tx_length_us(&cs->service, ZD_CS_RATE(cs->modulation),
		                 le16_to_cpu(cs->tx_length));
	if (r < 0)
		return r;
	cs->current_length = cpu_to_le16(r);

	if (next_frag_len == 0) {
		cs->next_frame_length = 0;
	} else {
		r = zd_calc_tx_length_us(NULL, ZD_CS_RATE(cs->modulation),
			                 next_frag_len);
		if (r < 0)
			return r;
		cs->next_frame_length = cpu_to_le16(r);
	}

	return 0;
}

static int zd_mac_tx(struct zd_mac *mac, struct ieee80211_txb *txb, int pri)
{
	int i, r;

	for (i = 0; i < txb->nr_frags; i++) {
		struct sk_buff *skb = txb->fragments[i];

		r = fill_ctrlset(mac, txb, i);
		if (r)
			return r;
		r = zd_usb_tx(&mac->chip.usb, skb->data, skb->len);
		if (r)
			return r;
	}

	/* FIXME: shouldn't this be handled by the upper layers? */
	mac->netdev->trans_start = jiffies;

	ieee80211_txb_free(txb);
	return 0;
}

struct zd_rt_hdr {
	struct ieee80211_radiotap_header rt_hdr;
	u8  rt_flags;
	u8  rt_rate;
	u16 rt_channel;
	u16 rt_chbitmask;
} __attribute__((packed));

static void fill_rt_header(void *buffer, struct zd_mac *mac,
	                   const struct ieee80211_rx_stats *stats,
			   const struct rx_status *status)
{
	struct zd_rt_hdr *hdr = buffer;

	hdr->rt_hdr.it_version = PKTHDR_RADIOTAP_VERSION;
	hdr->rt_hdr.it_pad = 0;
	hdr->rt_hdr.it_len = cpu_to_le16(sizeof(struct zd_rt_hdr));
	hdr->rt_hdr.it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
		                 (1 << IEEE80211_RADIOTAP_CHANNEL) |
				 (1 << IEEE80211_RADIOTAP_RATE));

	hdr->rt_flags = 0;
	if (status->decryption_type & (ZD_RX_WEP64|ZD_RX_WEP128|ZD_RX_WEP256))
		hdr->rt_flags |= IEEE80211_RADIOTAP_F_WEP;

	hdr->rt_rate = stats->rate / 5;

	/* FIXME: 802.11a */
	hdr->rt_channel = cpu_to_le16(ieee80211chan2mhz(
		                             _zd_chip_get_channel(&mac->chip)));
	hdr->rt_chbitmask = cpu_to_le16(IEEE80211_CHAN_2GHZ |
		((status->frame_status & ZD_RX_FRAME_MODULATION_MASK) ==
		ZD_RX_OFDM ? IEEE80211_CHAN_OFDM : IEEE80211_CHAN_CCK));
}

/* Returns 1 if the data packet is for us and 0 otherwise. */
static int is_data_packet_for_us(struct ieee80211_device *ieee,
	                         struct ieee80211_hdr_4addr *hdr)
{
	struct net_device *netdev = ieee->dev;
	u16 fc = le16_to_cpu(hdr->frame_ctl);

	ZD_ASSERT(WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA);

	switch (ieee->iw_mode) {
	case IW_MODE_ADHOC:
		if ((fc & (IEEE80211_FCTL_TODS|IEEE80211_FCTL_FROMDS)) != 0 ||
		    memcmp(hdr->addr3, ieee->bssid, ETH_ALEN) != 0)
			return 0;
		break;
	case IW_MODE_AUTO:
	case IW_MODE_INFRA:
		if ((fc & (IEEE80211_FCTL_TODS|IEEE80211_FCTL_FROMDS)) !=
		    IEEE80211_FCTL_FROMDS ||
		    memcmp(hdr->addr2, ieee->bssid, ETH_ALEN) != 0)
			return 0;
		break;
	default:
		ZD_ASSERT(ieee->iw_mode != IW_MODE_MONITOR);
		return 0;
	}

	return memcmp(hdr->addr1, netdev->dev_addr, ETH_ALEN) == 0 ||
	       is_multicast_ether_addr(hdr->addr1) ||
	       (netdev->flags & IFF_PROMISC);
}

/* Filters receiving packets. If it returns 1 send it to ieee80211_rx, if 0
 * return. If an error is detected -EINVAL is returned. ieee80211_rx_mgt() is
 * called here.
 *
 * It has been based on ieee80211_rx_any.
 */
static int filter_rx(struct ieee80211_device *ieee,
	             const u8 *buffer, unsigned int length,
		     struct ieee80211_rx_stats *stats)
{
	struct ieee80211_hdr_4addr *hdr;
	u16 fc;

	if (ieee->iw_mode == IW_MODE_MONITOR)
		return 1;

	hdr = (struct ieee80211_hdr_4addr *)buffer;
	fc = le16_to_cpu(hdr->frame_ctl);
	if ((fc & IEEE80211_FCTL_VERS) != 0)
		return -EINVAL;

	switch (WLAN_FC_GET_TYPE(fc)) {
	case IEEE80211_FTYPE_MGMT:
		if (length < sizeof(struct ieee80211_hdr_3addr))
			return -EINVAL;
		ieee80211_rx_mgt(ieee, hdr, stats);
		return 0;
	case IEEE80211_FTYPE_CTL:
		/* Ignore invalid short buffers */
		return 0;
	case IEEE80211_FTYPE_DATA:
		if (length < sizeof(struct ieee80211_hdr_3addr))
			return -EINVAL;
		return is_data_packet_for_us(ieee, hdr);
	}

	return -EINVAL;
}

static void update_qual_rssi(struct zd_mac *mac,
			     const u8 *buffer, unsigned int length,
			     u8 qual_percent, u8 rssi_percent)
{
	unsigned long flags;
	struct ieee80211_hdr_3addr *hdr;
	int i;

	hdr = (struct ieee80211_hdr_3addr *)buffer;
	if (length < offsetof(struct ieee80211_hdr_3addr, addr3))
		return;
	if (memcmp(hdr->addr2, zd_mac_to_ieee80211(mac)->bssid, ETH_ALEN) != 0)
		return;

	spin_lock_irqsave(&mac->lock, flags);
	i = mac->stats_count % ZD_MAC_STATS_BUFFER_SIZE;
	mac->qual_buffer[i] = qual_percent;
	mac->rssi_buffer[i] = rssi_percent;
	mac->stats_count++;
	spin_unlock_irqrestore(&mac->lock, flags);
}

static int fill_rx_stats(struct ieee80211_rx_stats *stats,
	                 const struct rx_status **pstatus,
		         struct zd_mac *mac,
			 const u8 *buffer, unsigned int length)
{
	const struct rx_status *status;

	*pstatus = status = zd_tail(buffer, length, sizeof(struct rx_status));
	if (status->frame_status & ZD_RX_ERROR) {
		/* FIXME: update? */
		return -EINVAL;
	}
	memset(stats, 0, sizeof(struct ieee80211_rx_stats));
	stats->len = length - (ZD_PLCP_HEADER_SIZE + IEEE80211_FCS_LEN +
		               + sizeof(struct rx_status));
	/* FIXME: 802.11a */
	stats->freq = IEEE80211_24GHZ_BAND;
	stats->received_channel = _zd_chip_get_channel(&mac->chip);
	stats->rssi = zd_rx_strength_percent(status->signal_strength);
	stats->signal = zd_rx_qual_percent(buffer,
		                          length - sizeof(struct rx_status),
		                          status);
	stats->mask = IEEE80211_STATMASK_RSSI | IEEE80211_STATMASK_SIGNAL;
	stats->rate = zd_rx_rate(buffer, status);
	if (stats->rate)
		stats->mask |= IEEE80211_STATMASK_RATE;

	return 0;
}

int zd_mac_rx(struct zd_mac *mac, const u8 *buffer, unsigned int length)
{
	int r;
	struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
	struct ieee80211_rx_stats stats;
	const struct rx_status *status;
	struct sk_buff *skb;

	if (length < ZD_PLCP_HEADER_SIZE + IEEE80211_1ADDR_LEN +
	             IEEE80211_FCS_LEN + sizeof(struct rx_status))
		return -EINVAL;

	r = fill_rx_stats(&stats, &status, mac, buffer, length);
	if (r)
		return r;

	length -= ZD_PLCP_HEADER_SIZE+IEEE80211_FCS_LEN+
		  sizeof(struct rx_status);
	buffer += ZD_PLCP_HEADER_SIZE;

	update_qual_rssi(mac, buffer, length, stats.signal, stats.rssi);

	r = filter_rx(ieee, buffer, length, &stats);
	if (r <= 0)
		return r;

	skb = dev_alloc_skb(sizeof(struct zd_rt_hdr) + length);
	if (!skb)
		return -ENOMEM;
	if (ieee->iw_mode == IW_MODE_MONITOR)
		fill_rt_header(skb_put(skb, sizeof(struct zd_rt_hdr)), mac,
			       &stats, status);
	memcpy(skb_put(skb, length), buffer, length);

	r = ieee80211_rx(ieee, skb, &stats);
	if (!r) {
		ZD_ASSERT(in_irq());
		dev_kfree_skb_irq(skb);
	}
	return 0;
}

static int netdev_tx(struct ieee80211_txb *txb, struct net_device *netdev,
		     int pri)
{
	return zd_mac_tx(zd_netdev_mac(netdev), txb, pri);
}

static void set_security(struct net_device *netdev,
			 struct ieee80211_security *sec)
{
	struct ieee80211_device *ieee = zd_netdev_ieee80211(netdev);
	struct ieee80211_security *secinfo = &ieee->sec;
	int keyidx;

	dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)), "\n");

	for (keyidx = 0; keyidx<WEP_KEYS; keyidx++)
		if (sec->flags & (1<<keyidx)) {
			secinfo->encode_alg[keyidx] = sec->encode_alg[keyidx];
			secinfo->key_sizes[keyidx] = sec->key_sizes[keyidx];
			memcpy(secinfo->keys[keyidx], sec->keys[keyidx],
			       SCM_KEY_LEN);
		}

	if (sec->flags & SEC_ACTIVE_KEY) {
		secinfo->active_key = sec->active_key;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .active_key = %d\n", sec->active_key);
	}
	if (sec->flags & SEC_UNICAST_GROUP) {
		secinfo->unicast_uses_group = sec->unicast_uses_group;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .unicast_uses_group = %d\n",
			sec->unicast_uses_group);
	}
	if (sec->flags & SEC_LEVEL) {
		secinfo->level = sec->level;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .level = %d\n", sec->level);
	}
	if (sec->flags & SEC_ENABLED) {
		secinfo->enabled = sec->enabled;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .enabled = %d\n", sec->enabled);
	}
	if (sec->flags & SEC_ENCRYPT) {
		secinfo->encrypt = sec->encrypt;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .encrypt = %d\n", sec->encrypt);
	}
	if (sec->flags & SEC_AUTH_MODE) {
		secinfo->auth_mode = sec->auth_mode;
		dev_dbg_f(zd_mac_dev(zd_netdev_mac(netdev)),
			"   .auth_mode = %d\n", sec->auth_mode);
	}
}

static void ieee_init(struct ieee80211_device *ieee)
{
	ieee->mode = IEEE_B | IEEE_G;
	ieee->freq_band = IEEE80211_24GHZ_BAND;
	ieee->modulation = IEEE80211_OFDM_MODULATION | IEEE80211_CCK_MODULATION;
	ieee->tx_headroom = sizeof(struct zd_ctrlset);
	ieee->set_security = set_security;
	ieee->hard_start_xmit = netdev_tx;

	/* Software encryption/decryption for now */
	ieee->host_build_iv = 0;
	ieee->host_encrypt = 1;
	ieee->host_decrypt = 1;

	/* FIXME: default to managed mode, until ieee80211 and zd1211rw can
	 * correctly support AUTO */
	ieee->iw_mode = IW_MODE_INFRA;
}

static void softmac_init(struct ieee80211softmac_device *sm)
{
	sm->set_channel = set_channel;
}

struct iw_statistics *zd_mac_get_wireless_stats(struct net_device *ndev)
{
	struct zd_mac *mac = zd_netdev_mac(ndev);
	struct iw_statistics *iw_stats = &mac->iw_stats;
	unsigned int i, count, qual_total, rssi_total;

	memset(iw_stats, 0, sizeof(struct iw_statistics));
	/* We are not setting the status, because ieee->state is not updated
	 * at all and this driver doesn't track authentication state.
	 */
	spin_lock_irq(&mac->lock);
	count = mac->stats_count < ZD_MAC_STATS_BUFFER_SIZE ?
		mac->stats_count : ZD_MAC_STATS_BUFFER_SIZE;
	qual_total = rssi_total = 0;
	for (i = 0; i < count; i++) {
		qual_total += mac->qual_buffer[i];
		rssi_total += mac->rssi_buffer[i];
	}
	spin_unlock_irq(&mac->lock);
	iw_stats->qual.updated = IW_QUAL_NOISE_INVALID;
	if (count > 0) {
		iw_stats->qual.qual = qual_total / count;
		iw_stats->qual.level = rssi_total / count;
		iw_stats->qual.updated |=
			IW_QUAL_QUAL_UPDATED|IW_QUAL_LEVEL_UPDATED;
	} else {
		iw_stats->qual.updated |=
			IW_QUAL_QUAL_INVALID|IW_QUAL_LEVEL_INVALID;
	}
	/* TODO: update counter */
	return iw_stats;
}

#ifdef DEBUG
static const char* decryption_types[] = {
	[ZD_RX_NO_WEP] = "none",
	[ZD_RX_WEP64] = "WEP64",
	[ZD_RX_TKIP] = "TKIP",
	[ZD_RX_AES] = "AES",
	[ZD_RX_WEP128] = "WEP128",
	[ZD_RX_WEP256] = "WEP256",
};

static const char *decryption_type_string(u8 type)
{
	const char *s;

	if (type < ARRAY_SIZE(decryption_types)) {
		s = decryption_types[type];
	} else {
		s = NULL;
	}
	return s ? s : "unknown";
}

static int is_ofdm(u8 frame_status)
{
	return (frame_status & ZD_RX_OFDM);
}

void zd_dump_rx_status(const struct rx_status *status)
{
	const char* modulation;
	u8 quality;

	if (is_ofdm(status->frame_status)) {
		modulation = "ofdm";
		quality = status->signal_quality_ofdm;
	} else {
		modulation = "cck";
		quality = status->signal_quality_cck;
	}
	pr_debug("rx status %s strength %#04x qual %#04x decryption %s\n",
		modulation, status->signal_strength, quality,
		decryption_type_string(status->decryption_type));
	if (status->frame_status & ZD_RX_ERROR) {
		pr_debug("rx error %s%s%s%s%s%s\n",
			(status->frame_status & ZD_RX_TIMEOUT_ERROR) ?
				"timeout " : "",
			(status->frame_status & ZD_RX_FIFO_OVERRUN_ERROR) ?
				"fifo " : "",
			(status->frame_status & ZD_RX_DECRYPTION_ERROR) ?
				"decryption " : "",
			(status->frame_status & ZD_RX_CRC32_ERROR) ?
				"crc32 " : "",
			(status->frame_status & ZD_RX_NO_ADDR1_MATCH_ERROR) ?
				"addr1 " : "",
			(status->frame_status & ZD_RX_CRC16_ERROR) ?
				"crc16" : "");
	}
}
#endif /* DEBUG */