- 根目录:
- drivers
- net
- wireless
- hostap
- hostap_80211_tx.c
#include <linux/slab.h>
#include "hostap_80211.h"
#include "hostap_common.h"
#include "hostap_wlan.h"
#include "hostap.h"
#include "hostap_ap.h"
/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
static unsigned char rfc1042_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
static unsigned char bridge_tunnel_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
/* No encapsulation header if EtherType < 0x600 (=length) */
void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr;
u16 fc;
hdr = (struct ieee80211_hdr *) skb->data;
printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
name, skb->len, jiffies);
if (skb->len < 2)
return;
fc = le16_to_cpu(hdr->frame_control);
printk(KERN_DEBUG " FC=0x%04x (type=%d:%d)%s%s",
fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
(fc & IEEE80211_FCTL_STYPE) >> 4,
fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
if (skb->len < IEEE80211_DATA_HDR3_LEN) {
printk("\n");
return;
}
printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
le16_to_cpu(hdr->seq_ctrl));
printk(KERN_DEBUG " A1=%pM", hdr->addr1);
printk(" A2=%pM", hdr->addr2);
printk(" A3=%pM", hdr->addr3);
if (skb->len >= 30)
printk(" A4=%pM", hdr->addr4);
printk("\n");
}
/* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
* Convert Ethernet header into a suitable IEEE 802.11 header depending on
* device configuration. */
netdev_tx_t hostap_data_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct hostap_interface *iface;
local_info_t *local;
int need_headroom, need_tailroom = 0;
struct ieee80211_hdr hdr;
u16 fc, ethertype = 0;
enum {
WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
} use_wds = WDS_NO;
u8 *encaps_data;
int hdr_len, encaps_len, skip_header_bytes;
int to_assoc_ap = 0;
struct hostap_skb_tx_data *meta;
iface = netdev_priv(dev);
local = iface->local;
if (skb->len < ETH_HLEN) {
printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
"(len=%d)\n", dev->name, skb->len);
kfree_skb(skb);
return NETDEV_TX_OK;
}
if (local->ddev != dev) {
use_wds = (local->iw_mode == IW_MODE_MASTER &&
!(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
if (dev == local->stadev) {
to_assoc_ap = 1;
use_wds = WDS_NO;
} else if (dev == local->apdev) {
printk(KERN_DEBUG "%s: prism2_tx: trying to use "
"AP device with Ethernet net dev\n", dev->name);
kfree_skb(skb);
return NETDEV_TX_OK;
}
} else {
if (local->iw_mode == IW_MODE_REPEAT) {
printk(KERN_DEBUG "%s: prism2_tx: trying to use "
"non-WDS link in Repeater mode\n", dev->name);
kfree_skb(skb);
return NETDEV_TX_OK;
} else if (local->iw_mode == IW_MODE_INFRA &&
(local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
memcmp(skb->data + ETH_ALEN, dev->dev_addr,
ETH_ALEN) != 0) {
/* AP client mode: send frames with foreign src addr
* using 4-addr WDS frames */
use_wds = WDS_COMPLIANT_FRAME;
}
}
/* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
* ==>
* Prism2 TX frame with 802.11 header:
* txdesc (address order depending on used mode; includes dst_addr and
* src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
* proto[2], payload {, possible addr4[6]} */
ethertype = (skb->data[12] << 8) | skb->data[13];
memset(&hdr, 0, sizeof(hdr));
/* Length of data after IEEE 802.11 header */
encaps_data = NULL;
encaps_len = 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;
}
fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
hdr_len = IEEE80211_DATA_HDR3_LEN;
if (use_wds != WDS_NO) {
/* Note! Prism2 station firmware has problems with sending real
* 802.11 frames with four addresses; until these problems can
* be fixed or worked around, 4-addr frames needed for WDS are
* using incompatible format: FromDS flag is not set and the
* fourth address is added after the frame payload; it is
* assumed, that the receiving station knows how to handle this
* frame format */
if (use_wds == WDS_COMPLIANT_FRAME) {
fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
/* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
* Addr4 = SA */
skb_copy_from_linear_data_offset(skb, ETH_ALEN,
&hdr.addr4, ETH_ALEN);
hdr_len += ETH_ALEN;
} else {
/* bogus 4-addr format to workaround Prism2 station
* f/w bug */
fc |= IEEE80211_FCTL_TODS;
/* From DS: Addr1 = DA (used as RA),
* Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
*/
/* SA from skb->data + ETH_ALEN will be added after
* frame payload; use hdr.addr4 as a temporary buffer
*/
skb_copy_from_linear_data_offset(skb, ETH_ALEN,
&hdr.addr4, ETH_ALEN);
need_tailroom += ETH_ALEN;
}
/* send broadcast and multicast frames to broadcast RA, if
* configured; otherwise, use unicast RA of the WDS link */
if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
skb->data[0] & 0x01)
memset(&hdr.addr1, 0xff, ETH_ALEN);
else if (iface->type == HOSTAP_INTERFACE_WDS)
memcpy(&hdr.addr1, iface->u.wds.remote_addr,
ETH_ALEN);
else
memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
} else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
fc |= IEEE80211_FCTL_FROMDS;
/* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
ETH_ALEN);
} else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
fc |= IEEE80211_FCTL_TODS;
/* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
memcpy(&hdr.addr1, to_assoc_ap ?
local->assoc_ap_addr : local->bssid, ETH_ALEN);
skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
ETH_ALEN);
skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
} else if (local->iw_mode == IW_MODE_ADHOC) {
/* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
ETH_ALEN);
memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
}
hdr.frame_control = cpu_to_le16(fc);
skb_pull(skb, skip_header_bytes);
need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
if (skb_tailroom(skb) < need_tailroom) {
skb = skb_unshare(skb, GFP_ATOMIC);
if (skb == NULL) {
iface->stats.tx_dropped++;
return NETDEV_TX_OK;
}
if (pskb_expand_head(skb, need_headroom, need_tailroom,
GFP_ATOMIC)) {
kfree_skb(skb);
iface->stats.tx_dropped++;
return NETDEV_TX_OK;
}
} else if (skb_headroom(skb) < need_headroom) {
struct sk_buff *tmp = skb;
skb = skb_realloc_headroom(skb, need_headroom);
kfree_skb(tmp);
if (skb == NULL) {
iface->stats.tx_dropped++;
return NETDEV_TX_OK;
}
} else {
skb = skb_unshare(skb, GFP_ATOMIC);
if (skb == NULL) {
iface->stats.tx_dropped++;
return NETDEV_TX_OK;
}
}
if (encaps_data)
memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
if (use_wds == WDS_OWN_FRAME) {
memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
}
iface->stats.tx_packets++;
iface->stats.tx_bytes += skb->len;
skb_reset_mac_header(skb);
meta = (struct hostap_skb_tx_data *) skb->cb;
memset(meta, 0, sizeof(*meta));
meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
if (use_wds)
meta->flags |= HOSTAP_TX_FLAGS_WDS;
meta->ethertype = ethertype;
meta->iface = iface;
/* Send IEEE 802.11 encapsulated frame using the master radio device */
skb->dev = local->dev;
dev_queue_xmit(skb);
return NETDEV_TX_OK;
}
/* hard_start_xmit function for hostapd wlan#ap interfaces */
netdev_tx_t hostap_mgmt_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct hostap_interface *iface;
local_info_t *local;
struct hostap_skb_tx_data *meta;
struct ieee80211_hdr *hdr;
u16 fc;
iface = netdev_priv(dev);
local = iface->local;
if (skb->len < 10) {
printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
"(len=%d)\n", dev->name, skb->len);
kfree_skb(skb);
return NETDEV_TX_OK;
}
iface->stats.tx_packets++;
iface->stats.tx_bytes += skb->len;
meta = (struct hostap_skb_tx_data *) skb->cb;
memset(meta, 0, sizeof(*meta));
meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
meta->iface = iface;
if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
hdr = (struct ieee80211_hdr *) skb->data;
fc = le16_to_cpu(hdr->frame_control);
if (ieee80211_is_data(hdr->frame_control) &&
(fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DATA) {
u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
sizeof(rfc1042_header)];
meta->ethertype = (pos[0] << 8) | pos[1];
}
}
/* Send IEEE 802.11 encapsulated frame using the master radio device */
skb->dev = local->dev;
dev_queue_xmit(skb);
return NETDEV_TX_OK;
}
/* Called only from software IRQ */
static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
struct lib80211_crypt_data *crypt)
{
struct hostap_interface *iface;
local_info_t *local;
struct ieee80211_hdr *hdr;
int prefix_len, postfix_len, hdr_len, res;
iface = netdev_priv(skb->dev);
local = iface->local;
if (skb->len < IEEE80211_DATA_HDR3_LEN) {
kfree_skb(skb);
return NULL;
}
if (local->tkip_countermeasures &&
strcmp(crypt->ops->name, "TKIP") == 0) {
hdr = (struct ieee80211_hdr *) skb->data;
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
"TX packet to %pM\n",
local->dev->name, hdr->addr1);
}
kfree_skb(skb);
return NULL;
}
skb = skb_unshare(skb, GFP_ATOMIC);
if (skb == NULL)
return NULL;
prefix_len = crypt->ops->extra_mpdu_prefix_len +
crypt->ops->extra_msdu_prefix_len;
postfix_len = crypt->ops->extra_mpdu_postfix_len +
crypt->ops->extra_msdu_postfix_len;
if ((skb_headroom(skb) < prefix_len ||
skb_tailroom(skb) < postfix_len) &&
pskb_expand_head(skb, prefix_len, postfix_len, GFP_ATOMIC)) {
kfree_skb(skb);
return NULL;
}
hdr = (struct ieee80211_hdr *) skb->data;
hdr_len = hostap_80211_get_hdrlen(hdr->frame_control);
/* 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(skb, hdr_len, crypt->priv);
if (res == 0 && crypt->ops->encrypt_mpdu)
res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
atomic_dec(&crypt->refcnt);
if (res < 0) {
kfree_skb(skb);
return NULL;
}
return skb;
}
/* hard_start_xmit function for master radio interface wifi#.
* AP processing (TX rate control, power save buffering, etc.).
* Use hardware TX function to send the frame. */
netdev_tx_t hostap_master_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct hostap_interface *iface;
local_info_t *local;
netdev_tx_t ret = NETDEV_TX_BUSY;
u16 fc;
struct hostap_tx_data tx;
ap_tx_ret tx_ret;
struct hostap_skb_tx_data *meta;
int no_encrypt = 0;
struct ieee80211_hdr *hdr;
iface = netdev_priv(dev);
local = iface->local;
tx.skb = skb;
tx.sta_ptr = NULL;
meta = (struct hostap_skb_tx_data *) skb->cb;
if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
"expected 0x%08x)\n",
dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
ret = NETDEV_TX_OK;
iface->stats.tx_dropped++;
goto fail;
}
if (local->host_encrypt) {
/* Set crypt to default algorithm and key; will be replaced in
* AP code if STA has own alg/key */
tx.crypt = local->crypt_info.crypt[local->crypt_info.tx_keyidx];
tx.host_encrypt = 1;
} else {
tx.crypt = NULL;
tx.host_encrypt = 0;
}
if (skb->len < 24) {
printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
"(len=%d)\n", dev->name, skb->len);
ret = NETDEV_TX_OK;
iface->stats.tx_dropped++;
goto fail;
}
/* FIX (?):
* Wi-Fi 802.11b test plan suggests that AP should ignore power save
* bit in authentication and (re)association frames and assume tha
* STA remains awake for the response. */
tx_ret = hostap_handle_sta_tx(local, &tx);
skb = tx.skb;
meta = (struct hostap_skb_tx_data *) skb->cb;
hdr = (struct ieee80211_hdr *) skb->data;
fc = le16_to_cpu(hdr->frame_control);
switch (tx_ret) {
case AP_TX_CONTINUE:
break;
case AP_TX_CONTINUE_NOT_AUTHORIZED:
if (local->ieee_802_1x &&
ieee80211_is_data(hdr->frame_control) &&
meta->ethertype != ETH_P_PAE &&
!(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
printk(KERN_DEBUG "%s: dropped frame to unauthorized "
"port (IEEE 802.1X): ethertype=0x%04x\n",
dev->name, meta->ethertype);
hostap_dump_tx_80211(dev->name, skb);
ret = NETDEV_TX_OK; /* drop packet */
iface->stats.tx_dropped++;
goto fail;
}
break;
case AP_TX_DROP:
ret = NETDEV_TX_OK; /* drop packet */
iface->stats.tx_dropped++;
goto fail;
case AP_TX_RETRY:
goto fail;
case AP_TX_BUFFERED:
/* do not free skb here, it will be freed when the
* buffered frame is sent/timed out */
ret = NETDEV_TX_OK;
goto tx_exit;
}
/* Request TX callback if protocol version is 2 in 802.11 header;
* this version 2 is a special case used between hostapd and kernel
* driver */
if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
meta->tx_cb_idx = local->ap->tx_callback_idx;
/* remove special version from the frame header */
fc &= ~IEEE80211_FCTL_VERS;
hdr->frame_control = cpu_to_le16(fc);
}
if (!ieee80211_is_data(hdr->frame_control)) {
no_encrypt = 1;
tx.crypt = NULL;
}
if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
!(fc & IEEE80211_FCTL_PROTECTED)) {
no_encrypt = 1;
PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
"unencrypted EAPOL frame\n", dev->name);
tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
}
if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
tx.crypt = NULL;
else if ((tx.crypt ||
local->crypt_info.crypt[local->crypt_info.tx_keyidx]) &&
!no_encrypt) {
/* Add ISWEP flag both for firmware and host based encryption
*/
fc |= IEEE80211_FCTL_PROTECTED;
hdr->frame_control = cpu_to_le16(fc);
} else if (local->drop_unencrypted &&
ieee80211_is_data(hdr->frame_control) &&
meta->ethertype != ETH_P_PAE) {
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: dropped unencrypted TX data "
"frame (drop_unencrypted=1)\n", dev->name);
}
iface->stats.tx_dropped++;
ret = NETDEV_TX_OK;
goto fail;
}
if (tx.crypt) {
skb = hostap_tx_encrypt(skb, tx.crypt);
if (skb == NULL) {
printk(KERN_DEBUG "%s: TX - encryption failed\n",
dev->name);
ret = NETDEV_TX_OK;
goto fail;
}
meta = (struct hostap_skb_tx_data *) skb->cb;
if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
"expected 0x%08x) after hostap_tx_encrypt\n",
dev->name, meta->magic,
HOSTAP_SKB_TX_DATA_MAGIC);
ret = NETDEV_TX_OK;
iface->stats.tx_dropped++;
goto fail;
}
}
if (local->func->tx == NULL || local->func->tx(skb, dev)) {
ret = NETDEV_TX_OK;
iface->stats.tx_dropped++;
} else {
ret = NETDEV_TX_OK;
iface->stats.tx_packets++;
iface->stats.tx_bytes += skb->len;
}
fail:
if (ret == NETDEV_TX_OK && skb)
dev_kfree_skb(skb);
tx_exit:
if (tx.sta_ptr)
hostap_handle_sta_release(tx.sta_ptr);
return ret;
}
EXPORT_SYMBOL(hostap_master_start_xmit);