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536 lines
15 KiB
536 lines
15 KiB
/******************************************************************************
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Copyright(c) 2003 - 2005 Intel Corporation. All rights reserved.
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This program is free software; you can redistribute it and/or modify it
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under the terms of version 2 of the GNU General Public License as
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published by the Free Software Foundation.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc., 59
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Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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The full GNU General Public License is included in this distribution in the
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file called LICENSE.
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Contact Information:
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Intel Linux Wireless <ilw@linux.intel.com>
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Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
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******************************************************************************/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/if_arp.h>
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#include <linux/in6.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/proc_fs.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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#include <linux/tcp.h>
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#include <linux/types.h>
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#include <linux/wireless.h>
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#include <linux/etherdevice.h>
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#include <asm/uaccess.h>
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#include "libipw.h"
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/*
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802.11 Data Frame
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,-------------------------------------------------------------------.
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Bytes | 2 | 2 | 6 | 6 | 6 | 2 | 0..2312 | 4 |
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|------|------|---------|---------|---------|------|---------|------|
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Desc. | ctrl | dura | DA/RA | TA | SA | Sequ | Frame | fcs |
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| | tion | (BSSID) | | | ence | data | |
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`--------------------------------------------------| |------'
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Total: 28 non-data bytes `----.----'
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.- 'Frame data' expands, if WEP enabled, to <----------'
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V
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,-----------------------.
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Bytes | 4 | 0-2296 | 4 |
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|-----|-----------|-----|
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Desc. | IV | Encrypted | ICV |
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| | Packet | |
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`-----| |-----'
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`-----.-----'
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.- 'Encrypted Packet' expands to
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V
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,---------------------------------------------------.
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Bytes | 1 | 1 | 1 | 3 | 2 | 0-2304 |
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|------|------|---------|----------|------|---------|
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Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP |
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| DSAP | SSAP | | | | Packet |
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| 0xAA | 0xAA |0x03 (UI)|0x00-00-F8| | |
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`----------------------------------------------------
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Total: 8 non-data bytes
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802.3 Ethernet Data Frame
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,-----------------------------------------.
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Bytes | 6 | 6 | 2 | Variable | 4 |
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|-------|-------|------|-----------|------|
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Desc. | Dest. | Source| Type | IP Packet | fcs |
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| MAC | MAC | | | |
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`-----------------------------------------'
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Total: 18 non-data bytes
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In the event that fragmentation is required, the incoming payload is split into
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N parts of size ieee->fts. The first fragment contains the SNAP header and the
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remaining packets are just data.
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If encryption is enabled, each fragment payload size is reduced by enough space
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to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP)
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So if you have 1500 bytes of payload with ieee->fts set to 500 without
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encryption it will take 3 frames. With WEP it will take 4 frames as the
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payload of each frame is reduced to 492 bytes.
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* SKB visualization
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*
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* ,- skb->data
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* |
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* | ETHERNET HEADER ,-<-- PAYLOAD
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* | | 14 bytes from skb->data
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* | 2 bytes for Type --> ,T. | (sizeof ethhdr)
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* | | | |
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* |,-Dest.--. ,--Src.---. | | |
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* | 6 bytes| | 6 bytes | | | |
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* v | | | | | |
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* 0 | v 1 | v | v 2
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* 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
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* ^ | ^ | ^ |
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* | | | | | |
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* | | | | `T' <---- 2 bytes for Type
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* | | | |
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* | | '---SNAP--' <-------- 6 bytes for SNAP
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* | |
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* `-IV--' <-------------------- 4 bytes for IV (WEP)
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*
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* SNAP HEADER
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*
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*/
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static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 };
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static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 };
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static int libipw_copy_snap(u8 * data, __be16 h_proto)
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{
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struct libipw_snap_hdr *snap;
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u8 *oui;
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snap = (struct libipw_snap_hdr *)data;
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snap->dsap = 0xaa;
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snap->ssap = 0xaa;
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snap->ctrl = 0x03;
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if (h_proto == htons(ETH_P_AARP) || h_proto == htons(ETH_P_IPX))
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oui = P802_1H_OUI;
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else
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oui = RFC1042_OUI;
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snap->oui[0] = oui[0];
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snap->oui[1] = oui[1];
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snap->oui[2] = oui[2];
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memcpy(data + SNAP_SIZE, &h_proto, sizeof(u16));
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return SNAP_SIZE + sizeof(u16);
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}
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static int libipw_encrypt_fragment(struct libipw_device *ieee,
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struct sk_buff *frag, int hdr_len)
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{
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struct lib80211_crypt_data *crypt =
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ieee->crypt_info.crypt[ieee->crypt_info.tx_keyidx];
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int res;
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if (crypt == NULL)
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return -1;
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/* To encrypt, frame format is:
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* IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */
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atomic_inc(&crypt->refcnt);
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res = 0;
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if (crypt->ops && crypt->ops->encrypt_mpdu)
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res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv);
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atomic_dec(&crypt->refcnt);
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if (res < 0) {
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printk(KERN_INFO "%s: Encryption failed: len=%d.\n",
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ieee->dev->name, frag->len);
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ieee->ieee_stats.tx_discards++;
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return -1;
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}
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return 0;
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}
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void libipw_txb_free(struct libipw_txb *txb)
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{
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int i;
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if (unlikely(!txb))
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return;
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for (i = 0; i < txb->nr_frags; i++)
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if (txb->fragments[i])
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dev_kfree_skb_any(txb->fragments[i]);
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kfree(txb);
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}
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static struct libipw_txb *libipw_alloc_txb(int nr_frags, int txb_size,
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int headroom, gfp_t gfp_mask)
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{
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struct libipw_txb *txb;
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int i;
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txb = kmalloc(sizeof(struct libipw_txb) + (sizeof(u8 *) * nr_frags),
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gfp_mask);
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if (!txb)
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return NULL;
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memset(txb, 0, sizeof(struct libipw_txb));
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txb->nr_frags = nr_frags;
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txb->frag_size = txb_size;
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for (i = 0; i < nr_frags; i++) {
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txb->fragments[i] = __dev_alloc_skb(txb_size + headroom,
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gfp_mask);
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if (unlikely(!txb->fragments[i])) {
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i--;
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break;
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}
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skb_reserve(txb->fragments[i], headroom);
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}
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if (unlikely(i != nr_frags)) {
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while (i >= 0)
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dev_kfree_skb_any(txb->fragments[i--]);
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kfree(txb);
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return NULL;
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}
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return txb;
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}
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static int libipw_classify(struct sk_buff *skb)
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{
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struct ethhdr *eth;
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struct iphdr *ip;
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eth = (struct ethhdr *)skb->data;
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if (eth->h_proto != htons(ETH_P_IP))
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return 0;
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ip = ip_hdr(skb);
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switch (ip->tos & 0xfc) {
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case 0x20:
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return 2;
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case 0x40:
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return 1;
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case 0x60:
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return 3;
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case 0x80:
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return 4;
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case 0xa0:
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return 5;
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case 0xc0:
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return 6;
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case 0xe0:
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return 7;
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default:
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return 0;
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}
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}
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/* Incoming skb is converted to a txb which consists of
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* a block of 802.11 fragment packets (stored as skbs) */
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netdev_tx_t libipw_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct libipw_device *ieee = netdev_priv(dev);
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struct libipw_txb *txb = NULL;
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struct libipw_hdr_3addrqos *frag_hdr;
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int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size,
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rts_required;
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unsigned long flags;
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int encrypt, host_encrypt, host_encrypt_msdu;
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__be16 ether_type;
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int bytes, fc, hdr_len;
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struct sk_buff *skb_frag;
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struct libipw_hdr_3addrqos header = {/* Ensure zero initialized */
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.duration_id = 0,
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.seq_ctl = 0,
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.qos_ctl = 0
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};
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u8 dest[ETH_ALEN], src[ETH_ALEN];
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struct lib80211_crypt_data *crypt;
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int priority = skb->priority;
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int snapped = 0;
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if (ieee->is_queue_full && (*ieee->is_queue_full) (dev, priority))
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return NETDEV_TX_BUSY;
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spin_lock_irqsave(&ieee->lock, flags);
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/* If there is no driver handler to take the TXB, dont' bother
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* creating it... */
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if (!ieee->hard_start_xmit) {
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printk(KERN_WARNING "%s: No xmit handler.\n", ieee->dev->name);
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goto success;
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}
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if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) {
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printk(KERN_WARNING "%s: skb too small (%d).\n",
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ieee->dev->name, skb->len);
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goto success;
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}
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ether_type = ((struct ethhdr *)skb->data)->h_proto;
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crypt = ieee->crypt_info.crypt[ieee->crypt_info.tx_keyidx];
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encrypt = !(ether_type == htons(ETH_P_PAE) && ieee->ieee802_1x) &&
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ieee->sec.encrypt;
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host_encrypt = ieee->host_encrypt && encrypt && crypt;
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host_encrypt_msdu = ieee->host_encrypt_msdu && encrypt && crypt;
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if (!encrypt && ieee->ieee802_1x &&
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ieee->drop_unencrypted && ether_type != htons(ETH_P_PAE)) {
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dev->stats.tx_dropped++;
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goto success;
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}
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/* Save source and destination addresses */
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skb_copy_from_linear_data(skb, dest, ETH_ALEN);
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skb_copy_from_linear_data_offset(skb, ETH_ALEN, src, ETH_ALEN);
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if (host_encrypt)
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fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA |
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IEEE80211_FCTL_PROTECTED;
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else
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fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
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if (ieee->iw_mode == IW_MODE_INFRA) {
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fc |= IEEE80211_FCTL_TODS;
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/* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
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memcpy(header.addr1, ieee->bssid, ETH_ALEN);
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memcpy(header.addr2, src, ETH_ALEN);
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memcpy(header.addr3, dest, ETH_ALEN);
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} else if (ieee->iw_mode == IW_MODE_ADHOC) {
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/* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
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memcpy(header.addr1, dest, ETH_ALEN);
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memcpy(header.addr2, src, ETH_ALEN);
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memcpy(header.addr3, ieee->bssid, ETH_ALEN);
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}
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hdr_len = LIBIPW_3ADDR_LEN;
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if (ieee->is_qos_active && ieee->is_qos_active(dev, skb)) {
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fc |= IEEE80211_STYPE_QOS_DATA;
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hdr_len += 2;
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skb->priority = libipw_classify(skb);
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header.qos_ctl |= cpu_to_le16(skb->priority & LIBIPW_QCTL_TID);
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}
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header.frame_ctl = cpu_to_le16(fc);
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/* Advance the SKB to the start of the payload */
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skb_pull(skb, sizeof(struct ethhdr));
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/* Determine total amount of storage required for TXB packets */
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bytes = skb->len + SNAP_SIZE + sizeof(u16);
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/* Encrypt msdu first on the whole data packet. */
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if ((host_encrypt || host_encrypt_msdu) &&
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crypt && crypt->ops && crypt->ops->encrypt_msdu) {
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int res = 0;
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int len = bytes + hdr_len + crypt->ops->extra_msdu_prefix_len +
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crypt->ops->extra_msdu_postfix_len;
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struct sk_buff *skb_new = dev_alloc_skb(len);
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if (unlikely(!skb_new))
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goto failed;
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skb_reserve(skb_new, crypt->ops->extra_msdu_prefix_len);
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memcpy(skb_put(skb_new, hdr_len), &header, hdr_len);
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snapped = 1;
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libipw_copy_snap(skb_put(skb_new, SNAP_SIZE + sizeof(u16)),
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ether_type);
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skb_copy_from_linear_data(skb, skb_put(skb_new, skb->len), skb->len);
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res = crypt->ops->encrypt_msdu(skb_new, hdr_len, crypt->priv);
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if (res < 0) {
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LIBIPW_ERROR("msdu encryption failed\n");
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dev_kfree_skb_any(skb_new);
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goto failed;
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}
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dev_kfree_skb_any(skb);
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skb = skb_new;
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bytes += crypt->ops->extra_msdu_prefix_len +
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crypt->ops->extra_msdu_postfix_len;
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skb_pull(skb, hdr_len);
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}
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if (host_encrypt || ieee->host_open_frag) {
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/* Determine fragmentation size based on destination (multicast
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* and broadcast are not fragmented) */
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if (is_multicast_ether_addr(dest) ||
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is_broadcast_ether_addr(dest))
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frag_size = MAX_FRAG_THRESHOLD;
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else
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frag_size = ieee->fts;
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/* Determine amount of payload per fragment. Regardless of if
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* this stack is providing the full 802.11 header, one will
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* eventually be affixed to this fragment -- so we must account
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* for it when determining the amount of payload space. */
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bytes_per_frag = frag_size - hdr_len;
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if (ieee->config &
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(CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS))
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bytes_per_frag -= LIBIPW_FCS_LEN;
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/* Each fragment may need to have room for encryption
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* pre/postfix */
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if (host_encrypt)
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bytes_per_frag -= crypt->ops->extra_mpdu_prefix_len +
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crypt->ops->extra_mpdu_postfix_len;
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/* Number of fragments is the total
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* bytes_per_frag / payload_per_fragment */
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nr_frags = bytes / bytes_per_frag;
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bytes_last_frag = bytes % bytes_per_frag;
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if (bytes_last_frag)
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nr_frags++;
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else
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bytes_last_frag = bytes_per_frag;
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} else {
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nr_frags = 1;
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bytes_per_frag = bytes_last_frag = bytes;
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frag_size = bytes + hdr_len;
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}
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rts_required = (frag_size > ieee->rts
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&& ieee->config & CFG_LIBIPW_RTS);
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if (rts_required)
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nr_frags++;
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|
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/* When we allocate the TXB we allocate enough space for the reserve
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* and full fragment bytes (bytes_per_frag doesn't include prefix,
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* postfix, header, FCS, etc.) */
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txb = libipw_alloc_txb(nr_frags, frag_size,
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ieee->tx_headroom, GFP_ATOMIC);
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if (unlikely(!txb)) {
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printk(KERN_WARNING "%s: Could not allocate TXB\n",
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ieee->dev->name);
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goto failed;
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}
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txb->encrypted = encrypt;
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if (host_encrypt)
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txb->payload_size = frag_size * (nr_frags - 1) +
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bytes_last_frag;
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else
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txb->payload_size = bytes;
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if (rts_required) {
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skb_frag = txb->fragments[0];
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frag_hdr =
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(struct libipw_hdr_3addrqos *)skb_put(skb_frag, hdr_len);
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/*
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* Set header frame_ctl to the RTS.
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*/
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header.frame_ctl =
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cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
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memcpy(frag_hdr, &header, hdr_len);
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/*
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* Restore header frame_ctl to the original data setting.
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*/
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header.frame_ctl = cpu_to_le16(fc);
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if (ieee->config &
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(CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS))
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skb_put(skb_frag, 4);
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txb->rts_included = 1;
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i = 1;
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} else
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i = 0;
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for (; i < nr_frags; i++) {
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skb_frag = txb->fragments[i];
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|
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if (host_encrypt)
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skb_reserve(skb_frag,
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crypt->ops->extra_mpdu_prefix_len);
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frag_hdr =
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(struct libipw_hdr_3addrqos *)skb_put(skb_frag, hdr_len);
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memcpy(frag_hdr, &header, hdr_len);
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|
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/* If this is not the last fragment, then add the MOREFRAGS
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|
* bit to the frame control */
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|
if (i != nr_frags - 1) {
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|
frag_hdr->frame_ctl =
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cpu_to_le16(fc | IEEE80211_FCTL_MOREFRAGS);
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|
bytes = bytes_per_frag;
|
|
} else {
|
|
/* The last fragment takes the remaining length */
|
|
bytes = bytes_last_frag;
|
|
}
|
|
|
|
if (i == 0 && !snapped) {
|
|
libipw_copy_snap(skb_put
|
|
(skb_frag, SNAP_SIZE + sizeof(u16)),
|
|
ether_type);
|
|
bytes -= SNAP_SIZE + sizeof(u16);
|
|
}
|
|
|
|
skb_copy_from_linear_data(skb, skb_put(skb_frag, bytes), 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)
|
|
libipw_encrypt_fragment(ieee, skb_frag, hdr_len);
|
|
|
|
if (ieee->config &
|
|
(CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS))
|
|
skb_put(skb_frag, 4);
|
|
}
|
|
|
|
success:
|
|
spin_unlock_irqrestore(&ieee->lock, flags);
|
|
|
|
dev_kfree_skb_any(skb);
|
|
|
|
if (txb) {
|
|
netdev_tx_t ret = (*ieee->hard_start_xmit)(txb, dev, priority);
|
|
if (ret == NETDEV_TX_OK) {
|
|
dev->stats.tx_packets++;
|
|
dev->stats.tx_bytes += txb->payload_size;
|
|
return NETDEV_TX_OK;
|
|
}
|
|
|
|
libipw_txb_free(txb);
|
|
}
|
|
|
|
return NETDEV_TX_OK;
|
|
|
|
failed:
|
|
spin_unlock_irqrestore(&ieee->lock, flags);
|
|
netif_stop_queue(dev);
|
|
dev->stats.tx_errors++;
|
|
return NETDEV_TX_BUSY;
|
|
}
|
|
EXPORT_SYMBOL(libipw_xmit);
|
|
|
|
EXPORT_SYMBOL(libipw_txb_free);
|
|
|