/* * Wireless utility functions * * Copyright 2007-2009 Johannes Berg */ #include #include #include #include #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; /* TODO: add definitions for the lengths to linux/ieee80211.h */ switch (params->cipher) { case WLAN_CIPHER_SUITE_WEP40: if (params->key_len != 5) return -EINVAL; break; case WLAN_CIPHER_SUITE_TKIP: if (params->key_len != 32) return -EINVAL; break; case WLAN_CIPHER_SUITE_CCMP: if (params->key_len != 16) return -EINVAL; break; case WLAN_CIPHER_SUITE_WEP104: if (params->key_len != 13) return -EINVAL; break; case WLAN_CIPHER_SUITE_AES_CMAC: if (params->key_len != 16) 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); 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);