| /****************************************************************************** |
| |
| Copyright(c) 2003 - 2004 Intel Corporation. All rights reserved. |
| |
| This program is free software; you can redistribute it and/or modify it |
| under the terms of version 2 of the GNU General Public License as |
| published by the Free Software Foundation. |
| |
| This program 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 |
| this program; if not, write to the Free Software Foundation, Inc., 59 |
| Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| |
| The full GNU General Public License is included in this distribution in the |
| file called LICENSE. |
| |
| Contact Information: |
| James P. Ketrenos <ipw2100-admin@linux.intel.com> |
| Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 |
| |
| ******************************************************************************/ |
| #include <linux/compiler.h> |
| #include <linux/config.h> |
| #include <linux/errno.h> |
| #include <linux/if_arp.h> |
| #include <linux/in6.h> |
| #include <linux/in.h> |
| #include <linux/ip.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/netdevice.h> |
| #include <linux/proc_fs.h> |
| #include <linux/skbuff.h> |
| #include <linux/slab.h> |
| #include <linux/tcp.h> |
| #include <linux/types.h> |
| #include <linux/version.h> |
| #include <linux/wireless.h> |
| #include <linux/etherdevice.h> |
| #include <asm/uaccess.h> |
| |
| #include <net/ieee80211.h> |
| |
| /* |
| |
| 802.11 Data Frame |
| |
| ,-------------------------------------------------------------------. |
| Bytes | 2 | 2 | 6 | 6 | 6 | 2 | 0..2312 | 4 | |
| |------|------|---------|---------|---------|------|---------|------| |
| Desc. | ctrl | dura | DA/RA | TA | SA | Sequ | Frame | fcs | |
| | | tion | (BSSID) | | | ence | data | | |
| `--------------------------------------------------| |------' |
| Total: 28 non-data bytes `----.----' |
| | |
| .- 'Frame data' expands to <---------------------------' |
| | |
| V |
| ,---------------------------------------------------. |
| Bytes | 1 | 1 | 1 | 3 | 2 | 0-2304 | |
| |------|------|---------|----------|------|---------| |
| Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP | |
| | DSAP | SSAP | | | | Packet | |
| | 0xAA | 0xAA |0x03 (UI)|0x00-00-F8| | | |
| `-----------------------------------------| | |
| Total: 8 non-data bytes `----.----' |
| | |
| .- 'IP Packet' expands, if WEP enabled, to <--' |
| | |
| V |
| ,-----------------------. |
| Bytes | 4 | 0-2296 | 4 | |
| |-----|-----------|-----| |
| Desc. | IV | Encrypted | ICV | |
| | | IP Packet | | |
| `-----------------------' |
| Total: 8 non-data bytes |
| |
| 802.3 Ethernet Data Frame |
| |
| ,-----------------------------------------. |
| Bytes | 6 | 6 | 2 | Variable | 4 | |
| |-------|-------|------|-----------|------| |
| Desc. | Dest. | Source| Type | IP Packet | fcs | |
| | MAC | MAC | | | | |
| `-----------------------------------------' |
| Total: 18 non-data bytes |
| |
| In the event that fragmentation is required, the incoming payload is split into |
| N parts of size ieee->fts. The first fragment contains the SNAP header and the |
| remaining packets are just data. |
| |
| If encryption is enabled, each fragment payload size is reduced by enough space |
| to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP) |
| So if you have 1500 bytes of payload with ieee->fts set to 500 without |
| encryption it will take 3 frames. With WEP it will take 4 frames as the |
| payload of each frame is reduced to 492 bytes. |
| |
| * SKB visualization |
| * |
| * ,- skb->data |
| * | |
| * | ETHERNET HEADER ,-<-- PAYLOAD |
| * | | 14 bytes from skb->data |
| * | 2 bytes for Type --> ,T. | (sizeof ethhdr) |
| * | | | | |
| * |,-Dest.--. ,--Src.---. | | | |
| * | 6 bytes| | 6 bytes | | | | |
| * v | | | | | | |
| * 0 | v 1 | v | v 2 |
| * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| * ^ | ^ | ^ | |
| * | | | | | | |
| * | | | | `T' <---- 2 bytes for Type |
| * | | | | |
| * | | '---SNAP--' <-------- 6 bytes for SNAP |
| * | | |
| * `-IV--' <-------------------- 4 bytes for IV (WEP) |
| * |
| * SNAP HEADER |
| * |
| */ |
| |
| static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 }; |
| static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 }; |
| |
| static inline int ieee80211_put_snap(u8 * data, u16 h_proto) |
| { |
| struct ieee80211_snap_hdr *snap; |
| u8 *oui; |
| |
| snap = (struct ieee80211_snap_hdr *)data; |
| snap->dsap = 0xaa; |
| snap->ssap = 0xaa; |
| snap->ctrl = 0x03; |
| |
| if (h_proto == 0x8137 || h_proto == 0x80f3) |
| oui = P802_1H_OUI; |
| else |
| oui = RFC1042_OUI; |
| snap->oui[0] = oui[0]; |
| snap->oui[1] = oui[1]; |
| snap->oui[2] = oui[2]; |
| |
| *(u16 *) (data + SNAP_SIZE) = htons(h_proto); |
| |
| return SNAP_SIZE + sizeof(u16); |
| } |
| |
| static inline int ieee80211_encrypt_fragment(struct ieee80211_device *ieee, |
| struct sk_buff *frag, int hdr_len) |
| { |
| struct ieee80211_crypt_data *crypt = ieee->crypt[ieee->tx_keyidx]; |
| int res; |
| |
| /* To encrypt, frame format is: |
| * IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */ |
| |
| // PR: FIXME: Copied from hostap. Check fragmentation/MSDU/MPDU encryption. |
| /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so |
| * call both MSDU and MPDU encryption functions from here. */ |
| atomic_inc(&crypt->refcnt); |
| res = 0; |
| if (crypt->ops->encrypt_msdu) |
| res = crypt->ops->encrypt_msdu(frag, hdr_len, crypt->priv); |
| if (res == 0 && crypt->ops->encrypt_mpdu) |
| res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv); |
| |
| atomic_dec(&crypt->refcnt); |
| if (res < 0) { |
| printk(KERN_INFO "%s: Encryption failed: len=%d.\n", |
| ieee->dev->name, frag->len); |
| ieee->ieee_stats.tx_discards++; |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| void ieee80211_txb_free(struct ieee80211_txb *txb) |
| { |
| int i; |
| if (unlikely(!txb)) |
| return; |
| for (i = 0; i < txb->nr_frags; i++) |
| if (txb->fragments[i]) |
| dev_kfree_skb_any(txb->fragments[i]); |
| kfree(txb); |
| } |
| |
| static struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size, |
| int gfp_mask) |
| { |
| struct ieee80211_txb *txb; |
| int i; |
| txb = kmalloc(sizeof(struct ieee80211_txb) + (sizeof(u8 *) * nr_frags), |
| gfp_mask); |
| if (!txb) |
| return NULL; |
| |
| memset(txb, 0, sizeof(struct ieee80211_txb)); |
| txb->nr_frags = nr_frags; |
| txb->frag_size = txb_size; |
| |
| for (i = 0; i < nr_frags; i++) { |
| txb->fragments[i] = dev_alloc_skb(txb_size); |
| if (unlikely(!txb->fragments[i])) { |
| i--; |
| break; |
| } |
| } |
| if (unlikely(i != nr_frags)) { |
| while (i >= 0) |
| dev_kfree_skb_any(txb->fragments[i--]); |
| kfree(txb); |
| return NULL; |
| } |
| return txb; |
| } |
| |
| /* SKBs are added to the ieee->tx_queue. */ |
| int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct ieee80211_device *ieee = netdev_priv(dev); |
| struct ieee80211_txb *txb = NULL; |
| struct ieee80211_hdr_3addr *frag_hdr; |
| int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size; |
| unsigned long flags; |
| struct net_device_stats *stats = &ieee->stats; |
| int ether_type, encrypt, host_encrypt; |
| int bytes, fc, hdr_len; |
| struct sk_buff *skb_frag; |
| struct ieee80211_hdr_3addr header = { /* Ensure zero initialized */ |
| .duration_id = 0, |
| .seq_ctl = 0 |
| }; |
| u8 dest[ETH_ALEN], src[ETH_ALEN]; |
| |
| struct ieee80211_crypt_data *crypt; |
| |
| spin_lock_irqsave(&ieee->lock, flags); |
| |
| /* If there is no driver handler to take the TXB, dont' bother |
| * creating it... */ |
| if (!ieee->hard_start_xmit) { |
| printk(KERN_WARNING "%s: No xmit handler.\n", ieee->dev->name); |
| goto success; |
| } |
| |
| if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) { |
| printk(KERN_WARNING "%s: skb too small (%d).\n", |
| ieee->dev->name, skb->len); |
| goto success; |
| } |
| |
| ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto); |
| |
| crypt = ieee->crypt[ieee->tx_keyidx]; |
| |
| encrypt = !(ether_type == ETH_P_PAE && ieee->ieee802_1x) && |
| ieee->sec.encrypt; |
| host_encrypt = ieee->host_encrypt && encrypt; |
| |
| if (!encrypt && ieee->ieee802_1x && |
| ieee->drop_unencrypted && ether_type != ETH_P_PAE) { |
| stats->tx_dropped++; |
| goto success; |
| } |
| |
| /* Save source and destination addresses */ |
| memcpy(dest, skb->data, ETH_ALEN); |
| memcpy(src, skb->data + ETH_ALEN, ETH_ALEN); |
| |
| /* Advance the SKB to the start of the payload */ |
| skb_pull(skb, sizeof(struct ethhdr)); |
| |
| /* Determine total amount of storage required for TXB packets */ |
| bytes = skb->len + SNAP_SIZE + sizeof(u16); |
| |
| if (host_encrypt) |
| fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA | |
| IEEE80211_FCTL_PROTECTED; |
| else |
| fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA; |
| |
| if (ieee->iw_mode == IW_MODE_INFRA) { |
| fc |= IEEE80211_FCTL_TODS; |
| /* To DS: Addr1 = BSSID, Addr2 = SA, |
| Addr3 = DA */ |
| memcpy(header.addr1, ieee->bssid, ETH_ALEN); |
| memcpy(header.addr2, src, ETH_ALEN); |
| memcpy(header.addr3, dest, ETH_ALEN); |
| } else if (ieee->iw_mode == IW_MODE_ADHOC) { |
| /* not From/To DS: Addr1 = DA, Addr2 = SA, |
| Addr3 = BSSID */ |
| memcpy(header.addr1, dest, ETH_ALEN); |
| memcpy(header.addr2, src, ETH_ALEN); |
| memcpy(header.addr3, ieee->bssid, ETH_ALEN); |
| } |
| header.frame_ctl = cpu_to_le16(fc); |
| hdr_len = IEEE80211_3ADDR_LEN; |
| |
| /* Determine fragmentation size based on destination (multicast |
| * and broadcast are not fragmented) */ |
| if (is_multicast_ether_addr(dest) || is_broadcast_ether_addr(dest)) |
| frag_size = MAX_FRAG_THRESHOLD; |
| else |
| frag_size = ieee->fts; |
| |
| /* Determine amount of payload per fragment. Regardless of if |
| * this stack is providing the full 802.11 header, one will |
| * eventually be affixed to this fragment -- so we must account for |
| * it when determining the amount of payload space. */ |
| bytes_per_frag = frag_size - IEEE80211_3ADDR_LEN; |
| if (ieee->config & |
| (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS)) |
| bytes_per_frag -= IEEE80211_FCS_LEN; |
| |
| /* Each fragment may need to have room for encryptiong pre/postfix */ |
| if (host_encrypt) |
| bytes_per_frag -= crypt->ops->extra_prefix_len + |
| crypt->ops->extra_postfix_len; |
| |
| /* Number of fragments is the total bytes_per_frag / |
| * payload_per_fragment */ |
| nr_frags = bytes / bytes_per_frag; |
| bytes_last_frag = bytes % bytes_per_frag; |
| if (bytes_last_frag) |
| nr_frags++; |
| else |
| bytes_last_frag = bytes_per_frag; |
| |
| /* When we allocate the TXB we allocate enough space for the reserve |
| * and full fragment bytes (bytes_per_frag doesn't include prefix, |
| * postfix, header, FCS, etc.) */ |
| txb = ieee80211_alloc_txb(nr_frags, frag_size, GFP_ATOMIC); |
| if (unlikely(!txb)) { |
| printk(KERN_WARNING "%s: Could not allocate TXB\n", |
| ieee->dev->name); |
| goto failed; |
| } |
| txb->encrypted = encrypt; |
| txb->payload_size = bytes; |
| |
| for (i = 0; i < nr_frags; i++) { |
| skb_frag = txb->fragments[i]; |
| |
| if (host_encrypt) |
| skb_reserve(skb_frag, crypt->ops->extra_prefix_len); |
| |
| frag_hdr = |
| (struct ieee80211_hdr_3addr *)skb_put(skb_frag, hdr_len); |
| memcpy(frag_hdr, &header, hdr_len); |
| |
| /* If this is not the last fragment, then add the MOREFRAGS |
| * bit to the frame control */ |
| if (i != nr_frags - 1) { |
| frag_hdr->frame_ctl = |
| cpu_to_le16(fc | IEEE80211_FCTL_MOREFRAGS); |
| bytes = bytes_per_frag; |
| } else { |
| /* The last fragment takes the remaining length */ |
| bytes = bytes_last_frag; |
| } |
| |
| /* Put a SNAP header on the first fragment */ |
| if (i == 0) { |
| ieee80211_put_snap(skb_put |
| (skb_frag, SNAP_SIZE + sizeof(u16)), |
| ether_type); |
| bytes -= SNAP_SIZE + sizeof(u16); |
| } |
| |
| memcpy(skb_put(skb_frag, bytes), skb->data, bytes); |
| |
| /* Advance the SKB... */ |
| skb_pull(skb, bytes); |
| |
| /* Encryption routine will move the header forward in order |
| * to insert the IV between the header and the payload */ |
| if (host_encrypt) |
| ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len); |
| |
| /* ipw2200/2915 Hardware encryption doesn't support TKIP MIC */ |
| if (!ieee->host_encrypt && encrypt && |
| (ieee->sec.level == SEC_LEVEL_2) && |
| crypt && crypt->ops && crypt->ops->encrypt_msdu) { |
| int res = 0; |
| res = crypt->ops->encrypt_msdu(skb_frag, hdr_len, |
| crypt->priv); |
| if (res < 0) { |
| IEEE80211_ERROR("TKIP MIC encryption failed\n"); |
| goto failed; |
| } |
| } |
| |
| if (ieee->config & |
| (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS)) |
| skb_put(skb_frag, 4); |
| } |
| |
| success: |
| spin_unlock_irqrestore(&ieee->lock, flags); |
| |
| dev_kfree_skb_any(skb); |
| |
| if (txb) { |
| if ((*ieee->hard_start_xmit) (txb, dev) == 0) { |
| stats->tx_packets++; |
| stats->tx_bytes += txb->payload_size; |
| return 0; |
| } |
| ieee80211_txb_free(txb); |
| } |
| |
| return 0; |
| |
| failed: |
| spin_unlock_irqrestore(&ieee->lock, flags); |
| netif_stop_queue(dev); |
| stats->tx_errors++; |
| return 1; |
| |
| } |
| |
| EXPORT_SYMBOL(ieee80211_txb_free); |