| /* | 
 |  * Wireless utility functions | 
 |  * | 
 |  * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net> | 
 |  */ | 
 | #include <linux/bitops.h> | 
 | #include <linux/etherdevice.h> | 
 | #include <net/cfg80211.h> | 
 | #include <net/ip.h> | 
 | #include "core.h" | 
 |  | 
 | struct ieee80211_rate * | 
 | ieee80211_get_response_rate(struct ieee80211_supported_band *sband, | 
 | 			    u32 basic_rates, int bitrate) | 
 | { | 
 | 	struct ieee80211_rate *result = &sband->bitrates[0]; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < sband->n_bitrates; i++) { | 
 | 		if (!(basic_rates & BIT(i))) | 
 | 			continue; | 
 | 		if (sband->bitrates[i].bitrate > bitrate) | 
 | 			continue; | 
 | 		result = &sband->bitrates[i]; | 
 | 	} | 
 |  | 
 | 	return result; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_get_response_rate); | 
 |  | 
 | int ieee80211_channel_to_frequency(int chan) | 
 | { | 
 | 	if (chan < 14) | 
 | 		return 2407 + chan * 5; | 
 |  | 
 | 	if (chan == 14) | 
 | 		return 2484; | 
 |  | 
 | 	/* FIXME: 802.11j 17.3.8.3.2 */ | 
 | 	return (chan + 1000) * 5; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_channel_to_frequency); | 
 |  | 
 | int ieee80211_frequency_to_channel(int freq) | 
 | { | 
 | 	if (freq == 2484) | 
 | 		return 14; | 
 |  | 
 | 	if (freq < 2484) | 
 | 		return (freq - 2407) / 5; | 
 |  | 
 | 	/* FIXME: 802.11j 17.3.8.3.2 */ | 
 | 	return freq/5 - 1000; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_frequency_to_channel); | 
 |  | 
 | struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy, | 
 | 						  int freq) | 
 | { | 
 | 	enum ieee80211_band band; | 
 | 	struct ieee80211_supported_band *sband; | 
 | 	int i; | 
 |  | 
 | 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) { | 
 | 		sband = wiphy->bands[band]; | 
 |  | 
 | 		if (!sband) | 
 | 			continue; | 
 |  | 
 | 		for (i = 0; i < sband->n_channels; i++) { | 
 | 			if (sband->channels[i].center_freq == freq) | 
 | 				return &sband->channels[i]; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 | EXPORT_SYMBOL(__ieee80211_get_channel); | 
 |  | 
 | static void set_mandatory_flags_band(struct ieee80211_supported_band *sband, | 
 | 				     enum ieee80211_band band) | 
 | { | 
 | 	int i, want; | 
 |  | 
 | 	switch (band) { | 
 | 	case IEEE80211_BAND_5GHZ: | 
 | 		want = 3; | 
 | 		for (i = 0; i < sband->n_bitrates; i++) { | 
 | 			if (sband->bitrates[i].bitrate == 60 || | 
 | 			    sband->bitrates[i].bitrate == 120 || | 
 | 			    sband->bitrates[i].bitrate == 240) { | 
 | 				sband->bitrates[i].flags |= | 
 | 					IEEE80211_RATE_MANDATORY_A; | 
 | 				want--; | 
 | 			} | 
 | 		} | 
 | 		WARN_ON(want); | 
 | 		break; | 
 | 	case IEEE80211_BAND_2GHZ: | 
 | 		want = 7; | 
 | 		for (i = 0; i < sband->n_bitrates; i++) { | 
 | 			if (sband->bitrates[i].bitrate == 10) { | 
 | 				sband->bitrates[i].flags |= | 
 | 					IEEE80211_RATE_MANDATORY_B | | 
 | 					IEEE80211_RATE_MANDATORY_G; | 
 | 				want--; | 
 | 			} | 
 |  | 
 | 			if (sband->bitrates[i].bitrate == 20 || | 
 | 			    sband->bitrates[i].bitrate == 55 || | 
 | 			    sband->bitrates[i].bitrate == 110 || | 
 | 			    sband->bitrates[i].bitrate == 60 || | 
 | 			    sband->bitrates[i].bitrate == 120 || | 
 | 			    sband->bitrates[i].bitrate == 240) { | 
 | 				sband->bitrates[i].flags |= | 
 | 					IEEE80211_RATE_MANDATORY_G; | 
 | 				want--; | 
 | 			} | 
 |  | 
 | 			if (sband->bitrates[i].bitrate != 10 && | 
 | 			    sband->bitrates[i].bitrate != 20 && | 
 | 			    sband->bitrates[i].bitrate != 55 && | 
 | 			    sband->bitrates[i].bitrate != 110) | 
 | 				sband->bitrates[i].flags |= | 
 | 					IEEE80211_RATE_ERP_G; | 
 | 		} | 
 | 		WARN_ON(want != 0 && want != 3 && want != 6); | 
 | 		break; | 
 | 	case IEEE80211_NUM_BANDS: | 
 | 		WARN_ON(1); | 
 | 		break; | 
 | 	} | 
 | } | 
 |  | 
 | void ieee80211_set_bitrate_flags(struct wiphy *wiphy) | 
 | { | 
 | 	enum ieee80211_band band; | 
 |  | 
 | 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) | 
 | 		if (wiphy->bands[band]) | 
 | 			set_mandatory_flags_band(wiphy->bands[band], band); | 
 | } | 
 |  | 
 | int cfg80211_validate_key_settings(struct key_params *params, int key_idx, | 
 | 				   const u8 *mac_addr) | 
 | { | 
 | 	if (key_idx > 5) | 
 | 		return -EINVAL; | 
 |  | 
 | 	/* | 
 | 	 * Disallow pairwise keys with non-zero index unless it's WEP | 
 | 	 * (because current deployments use pairwise WEP keys with | 
 | 	 * non-zero indizes but 802.11i clearly specifies to use zero) | 
 | 	 */ | 
 | 	if (mac_addr && key_idx && | 
 | 	    params->cipher != WLAN_CIPHER_SUITE_WEP40 && | 
 | 	    params->cipher != WLAN_CIPHER_SUITE_WEP104) | 
 | 		return -EINVAL; | 
 |  | 
 | 	switch (params->cipher) { | 
 | 	case WLAN_CIPHER_SUITE_WEP40: | 
 | 		if (params->key_len != WLAN_KEY_LEN_WEP40) | 
 | 			return -EINVAL; | 
 | 		break; | 
 | 	case WLAN_CIPHER_SUITE_TKIP: | 
 | 		if (params->key_len != WLAN_KEY_LEN_TKIP) | 
 | 			return -EINVAL; | 
 | 		break; | 
 | 	case WLAN_CIPHER_SUITE_CCMP: | 
 | 		if (params->key_len != WLAN_KEY_LEN_CCMP) | 
 | 			return -EINVAL; | 
 | 		break; | 
 | 	case WLAN_CIPHER_SUITE_WEP104: | 
 | 		if (params->key_len != WLAN_KEY_LEN_WEP104) | 
 | 			return -EINVAL; | 
 | 		break; | 
 | 	case WLAN_CIPHER_SUITE_AES_CMAC: | 
 | 		if (params->key_len != WLAN_KEY_LEN_AES_CMAC) | 
 | 			return -EINVAL; | 
 | 		break; | 
 | 	default: | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	if (params->seq) { | 
 | 		switch (params->cipher) { | 
 | 		case WLAN_CIPHER_SUITE_WEP40: | 
 | 		case WLAN_CIPHER_SUITE_WEP104: | 
 | 			/* These ciphers do not use key sequence */ | 
 | 			return -EINVAL; | 
 | 		case WLAN_CIPHER_SUITE_TKIP: | 
 | 		case WLAN_CIPHER_SUITE_CCMP: | 
 | 		case WLAN_CIPHER_SUITE_AES_CMAC: | 
 | 			if (params->seq_len != 6) | 
 | 				return -EINVAL; | 
 | 			break; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */ | 
 | /* Ethernet-II snap header (RFC1042 for most EtherTypes) */ | 
 | const unsigned char rfc1042_header[] __aligned(2) = | 
 | 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 }; | 
 | EXPORT_SYMBOL(rfc1042_header); | 
 |  | 
 | /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */ | 
 | const unsigned char bridge_tunnel_header[] __aligned(2) = | 
 | 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 }; | 
 | EXPORT_SYMBOL(bridge_tunnel_header); | 
 |  | 
 | unsigned int ieee80211_hdrlen(__le16 fc) | 
 | { | 
 | 	unsigned int hdrlen = 24; | 
 |  | 
 | 	if (ieee80211_is_data(fc)) { | 
 | 		if (ieee80211_has_a4(fc)) | 
 | 			hdrlen = 30; | 
 | 		if (ieee80211_is_data_qos(fc)) | 
 | 			hdrlen += IEEE80211_QOS_CTL_LEN; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (ieee80211_is_ctl(fc)) { | 
 | 		/* | 
 | 		 * ACK and CTS are 10 bytes, all others 16. To see how | 
 | 		 * to get this condition consider | 
 | 		 *   subtype mask:   0b0000000011110000 (0x00F0) | 
 | 		 *   ACK subtype:    0b0000000011010000 (0x00D0) | 
 | 		 *   CTS subtype:    0b0000000011000000 (0x00C0) | 
 | 		 *   bits that matter:         ^^^      (0x00E0) | 
 | 		 *   value of those: 0b0000000011000000 (0x00C0) | 
 | 		 */ | 
 | 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0)) | 
 | 			hdrlen = 10; | 
 | 		else | 
 | 			hdrlen = 16; | 
 | 	} | 
 | out: | 
 | 	return hdrlen; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_hdrlen); | 
 |  | 
 | unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) | 
 | { | 
 | 	const struct ieee80211_hdr *hdr = | 
 | 			(const struct ieee80211_hdr *)skb->data; | 
 | 	unsigned int hdrlen; | 
 |  | 
 | 	if (unlikely(skb->len < 10)) | 
 | 		return 0; | 
 | 	hdrlen = ieee80211_hdrlen(hdr->frame_control); | 
 | 	if (unlikely(hdrlen > skb->len)) | 
 | 		return 0; | 
 | 	return hdrlen; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); | 
 |  | 
 | static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) | 
 | { | 
 | 	int ae = meshhdr->flags & MESH_FLAGS_AE; | 
 | 	/* 7.1.3.5a.2 */ | 
 | 	switch (ae) { | 
 | 	case 0: | 
 | 		return 6; | 
 | 	case 1: | 
 | 		return 12; | 
 | 	case 2: | 
 | 		return 18; | 
 | 	case 3: | 
 | 		return 24; | 
 | 	default: | 
 | 		return 6; | 
 | 	} | 
 | } | 
 |  | 
 | int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr, | 
 | 			   enum nl80211_iftype iftype) | 
 | { | 
 | 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | 
 | 	u16 hdrlen, ethertype; | 
 | 	u8 *payload; | 
 | 	u8 dst[ETH_ALEN]; | 
 | 	u8 src[ETH_ALEN] __aligned(2); | 
 |  | 
 | 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control))) | 
 | 		return -1; | 
 |  | 
 | 	hdrlen = ieee80211_hdrlen(hdr->frame_control); | 
 |  | 
 | 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet | 
 | 	 * header | 
 | 	 * IEEE 802.11 address fields: | 
 | 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4 | 
 | 	 *   0     0   DA    SA    BSSID n/a | 
 | 	 *   0     1   DA    BSSID SA    n/a | 
 | 	 *   1     0   BSSID SA    DA    n/a | 
 | 	 *   1     1   RA    TA    DA    SA | 
 | 	 */ | 
 | 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN); | 
 | 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN); | 
 |  | 
 | 	switch (hdr->frame_control & | 
 | 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { | 
 | 	case cpu_to_le16(IEEE80211_FCTL_TODS): | 
 | 		if (unlikely(iftype != NL80211_IFTYPE_AP && | 
 | 			     iftype != NL80211_IFTYPE_AP_VLAN)) | 
 | 			return -1; | 
 | 		break; | 
 | 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): | 
 | 		if (unlikely(iftype != NL80211_IFTYPE_WDS && | 
 | 			     iftype != NL80211_IFTYPE_MESH_POINT)) | 
 | 			return -1; | 
 | 		if (iftype == NL80211_IFTYPE_MESH_POINT) { | 
 | 			struct ieee80211s_hdr *meshdr = | 
 | 				(struct ieee80211s_hdr *) (skb->data + hdrlen); | 
 | 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr); | 
 | 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) { | 
 | 				memcpy(dst, meshdr->eaddr1, ETH_ALEN); | 
 | 				memcpy(src, meshdr->eaddr2, ETH_ALEN); | 
 | 			} | 
 | 		} | 
 | 		break; | 
 | 	case cpu_to_le16(IEEE80211_FCTL_FROMDS): | 
 | 		if (iftype != NL80211_IFTYPE_STATION || | 
 | 		    (is_multicast_ether_addr(dst) && | 
 | 		     !compare_ether_addr(src, addr))) | 
 | 			return -1; | 
 | 		break; | 
 | 	case cpu_to_le16(0): | 
 | 		if (iftype != NL80211_IFTYPE_ADHOC) | 
 | 			return -1; | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	if (unlikely(skb->len - hdrlen < 8)) | 
 | 		return -1; | 
 |  | 
 | 	payload = skb->data + hdrlen; | 
 | 	ethertype = (payload[6] << 8) | payload[7]; | 
 |  | 
 | 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 && | 
 | 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) || | 
 | 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) { | 
 | 		/* remove RFC1042 or Bridge-Tunnel encapsulation and | 
 | 		 * replace EtherType */ | 
 | 		skb_pull(skb, hdrlen + 6); | 
 | 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN); | 
 | 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN); | 
 | 	} else { | 
 | 		struct ethhdr *ehdr; | 
 | 		__be16 len; | 
 |  | 
 | 		skb_pull(skb, hdrlen); | 
 | 		len = htons(skb->len); | 
 | 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr)); | 
 | 		memcpy(ehdr->h_dest, dst, ETH_ALEN); | 
 | 		memcpy(ehdr->h_source, src, ETH_ALEN); | 
 | 		ehdr->h_proto = len; | 
 | 	} | 
 | 	return 0; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_data_to_8023); | 
 |  | 
 | int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr, | 
 | 			     enum nl80211_iftype iftype, u8 *bssid, bool qos) | 
 | { | 
 | 	struct ieee80211_hdr hdr; | 
 | 	u16 hdrlen, ethertype; | 
 | 	__le16 fc; | 
 | 	const u8 *encaps_data; | 
 | 	int encaps_len, skip_header_bytes; | 
 | 	int nh_pos, h_pos; | 
 | 	int head_need; | 
 |  | 
 | 	if (unlikely(skb->len < ETH_HLEN)) | 
 | 		return -EINVAL; | 
 |  | 
 | 	nh_pos = skb_network_header(skb) - skb->data; | 
 | 	h_pos = skb_transport_header(skb) - skb->data; | 
 |  | 
 | 	/* convert Ethernet header to proper 802.11 header (based on | 
 | 	 * operation mode) */ | 
 | 	ethertype = (skb->data[12] << 8) | skb->data[13]; | 
 | 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA); | 
 |  | 
 | 	switch (iftype) { | 
 | 	case NL80211_IFTYPE_AP: | 
 | 	case NL80211_IFTYPE_AP_VLAN: | 
 | 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS); | 
 | 		/* DA BSSID SA */ | 
 | 		memcpy(hdr.addr1, skb->data, ETH_ALEN); | 
 | 		memcpy(hdr.addr2, addr, ETH_ALEN); | 
 | 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN); | 
 | 		hdrlen = 24; | 
 | 		break; | 
 | 	case NL80211_IFTYPE_STATION: | 
 | 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS); | 
 | 		/* BSSID SA DA */ | 
 | 		memcpy(hdr.addr1, bssid, ETH_ALEN); | 
 | 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN); | 
 | 		memcpy(hdr.addr3, skb->data, ETH_ALEN); | 
 | 		hdrlen = 24; | 
 | 		break; | 
 | 	case NL80211_IFTYPE_ADHOC: | 
 | 		/* DA SA BSSID */ | 
 | 		memcpy(hdr.addr1, skb->data, ETH_ALEN); | 
 | 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN); | 
 | 		memcpy(hdr.addr3, bssid, ETH_ALEN); | 
 | 		hdrlen = 24; | 
 | 		break; | 
 | 	default: | 
 | 		return -EOPNOTSUPP; | 
 | 	} | 
 |  | 
 | 	if (qos) { | 
 | 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA); | 
 | 		hdrlen += 2; | 
 | 	} | 
 |  | 
 | 	hdr.frame_control = fc; | 
 | 	hdr.duration_id = 0; | 
 | 	hdr.seq_ctrl = 0; | 
 |  | 
 | 	skip_header_bytes = ETH_HLEN; | 
 | 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) { | 
 | 		encaps_data = bridge_tunnel_header; | 
 | 		encaps_len = sizeof(bridge_tunnel_header); | 
 | 		skip_header_bytes -= 2; | 
 | 	} else if (ethertype > 0x600) { | 
 | 		encaps_data = rfc1042_header; | 
 | 		encaps_len = sizeof(rfc1042_header); | 
 | 		skip_header_bytes -= 2; | 
 | 	} else { | 
 | 		encaps_data = NULL; | 
 | 		encaps_len = 0; | 
 | 	} | 
 |  | 
 | 	skb_pull(skb, skip_header_bytes); | 
 | 	nh_pos -= skip_header_bytes; | 
 | 	h_pos -= skip_header_bytes; | 
 |  | 
 | 	head_need = hdrlen + encaps_len - skb_headroom(skb); | 
 |  | 
 | 	if (head_need > 0 || skb_cloned(skb)) { | 
 | 		head_need = max(head_need, 0); | 
 | 		if (head_need) | 
 | 			skb_orphan(skb); | 
 |  | 
 | 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) { | 
 | 			printk(KERN_ERR "failed to reallocate Tx buffer\n"); | 
 | 			return -ENOMEM; | 
 | 		} | 
 | 		skb->truesize += head_need; | 
 | 	} | 
 |  | 
 | 	if (encaps_data) { | 
 | 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len); | 
 | 		nh_pos += encaps_len; | 
 | 		h_pos += encaps_len; | 
 | 	} | 
 |  | 
 | 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen); | 
 |  | 
 | 	nh_pos += hdrlen; | 
 | 	h_pos += hdrlen; | 
 |  | 
 | 	/* Update skb pointers to various headers since this modified frame | 
 | 	 * is going to go through Linux networking code that may potentially | 
 | 	 * need things like pointer to IP header. */ | 
 | 	skb_set_mac_header(skb, 0); | 
 | 	skb_set_network_header(skb, nh_pos); | 
 | 	skb_set_transport_header(skb, h_pos); | 
 |  | 
 | 	return 0; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_data_from_8023); | 
 |  | 
 | /* Given a data frame determine the 802.1p/1d tag to use. */ | 
 | unsigned int cfg80211_classify8021d(struct sk_buff *skb) | 
 | { | 
 | 	unsigned int dscp; | 
 |  | 
 | 	/* skb->priority values from 256->263 are magic values to | 
 | 	 * directly indicate a specific 802.1d priority.  This is used | 
 | 	 * to allow 802.1d priority to be passed directly in from VLAN | 
 | 	 * tags, etc. | 
 | 	 */ | 
 | 	if (skb->priority >= 256 && skb->priority <= 263) | 
 | 		return skb->priority - 256; | 
 |  | 
 | 	switch (skb->protocol) { | 
 | 	case htons(ETH_P_IP): | 
 | 		dscp = ip_hdr(skb)->tos & 0xfc; | 
 | 		break; | 
 | 	default: | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	return dscp >> 5; | 
 | } | 
 | EXPORT_SYMBOL(cfg80211_classify8021d); |