diff options
Diffstat (limited to 'net/wireless/util.c')
| -rw-r--r-- | net/wireless/util.c | 370 |
1 files changed, 367 insertions, 3 deletions
diff --git a/net/wireless/util.c b/net/wireless/util.c index 487cdd9bcff..25550692dda 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -1,10 +1,12 @@ /* * Wireless utility functions * - * Copyright 2007 Johannes Berg <johannes@sipsolutions.net> + * Copyright 2007-2009 Johannes Berg <johannes@sipsolutions.net> */ -#include <net/wireless.h> -#include <asm/bitops.h> +#include <linux/bitops.h> +#include <linux/etherdevice.h> +#include <net/cfg80211.h> +#include <net/ip.h> #include "core.h" struct ieee80211_rate * @@ -138,3 +140,365 @@ void ieee80211_set_bitrate_flags(struct wiphy *wiphy) 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); |