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-rw-r--r--net/ieee80211/ieee80211_tx.c438
1 files changed, 438 insertions, 0 deletions
diff --git a/net/ieee80211/ieee80211_tx.c b/net/ieee80211/ieee80211_tx.c
new file mode 100644
index 00000000000..b7ea3e25e25
--- /dev/null
+++ b/net/ieee80211/ieee80211_tx.c
@@ -0,0 +1,438 @@
+/******************************************************************************
+
+ 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;
+
+#ifdef CONFIG_IEEE80211_CRYPT_TKIP
+ struct ieee80211_hdr *header;
+
+ if (ieee->tkip_countermeasures &&
+ crypt && crypt->ops && strcmp(crypt->ops->name, "TKIP") == 0) {
+ header = (struct ieee80211_hdr *) frag->data;
+ if (net_ratelimit()) {
+ printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
+ "TX packet to " MAC_FMT "\n",
+ ieee->dev->name, MAC_ARG(header->addr1));
+ }
+ return -1;
+ }
+#endif
+ /* 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 *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;
+ int bytes, fc, hdr_len;
+ struct sk_buff *skb_frag;
+ struct ieee80211_hdr 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->host_encrypt && crypt && crypt->ops;
+
+ 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 (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 (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 (encrypt)
+ skb_reserve(skb_frag, crypt->ops->extra_prefix_len);
+
+ frag_hdr = (struct ieee80211_hdr *)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 (encrypt)
+ ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
+ 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);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-22 09:19:18 +0000