mac80211: use skb list for fragments
We are currently linking the skbs by using skb->next
directly. This works, but the preferred way is to use
a struct sk_buff_head instead. That also prepares for
passing that to drivers directly.
While at it I noticed we calculate the duration for
fragments twice -- remove one of them.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 068cc92..f278505 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -142,6 +142,7 @@
struct ieee80211_tx_data {
struct sk_buff *skb;
+ struct sk_buff_head skbs;
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4319883..26a7cfb 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -35,7 +35,8 @@
/* misc utils */
-static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
+static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
+ struct sk_buff *skb, int group_addr,
int next_frag_len)
{
int rate, mrate, erp, dur, i;
@@ -43,7 +44,7 @@
struct ieee80211_local *local = tx->local;
struct ieee80211_supported_band *sband;
struct ieee80211_hdr *hdr;
- struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
/* assume HW handles this */
if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
@@ -75,7 +76,7 @@
* at the highest possible rate belonging to the PHY rates in the
* BSSBasicRateSet
*/
- hdr = (struct ieee80211_hdr *)tx->skb->data;
+ hdr = (struct ieee80211_hdr *)skb->data;
if (ieee80211_is_ctl(hdr->frame_control)) {
/* TODO: These control frames are not currently sent by
* mac80211, but should they be implemented, this function
@@ -841,11 +842,12 @@
return TX_CONTINUE;
}
-static int ieee80211_fragment(struct ieee80211_local *local,
+static int ieee80211_fragment(struct ieee80211_tx_data *tx,
struct sk_buff *skb, int hdrlen,
int frag_threshold)
{
- struct sk_buff *tail = skb, *tmp;
+ struct ieee80211_local *local = tx->local;
+ struct sk_buff *tmp;
int per_fragm = frag_threshold - hdrlen - FCS_LEN;
int pos = hdrlen + per_fragm;
int rem = skb->len - hdrlen - per_fragm;
@@ -853,6 +855,8 @@
if (WARN_ON(rem < 0))
return -EINVAL;
+ /* first fragment was already added to queue by caller */
+
while (rem) {
int fraglen = per_fragm;
@@ -865,8 +869,9 @@
IEEE80211_ENCRYPT_TAILROOM);
if (!tmp)
return -ENOMEM;
- tail->next = tmp;
- tail = tmp;
+
+ __skb_queue_tail(&tx->skbs, tmp);
+
skb_reserve(tmp, local->tx_headroom +
IEEE80211_ENCRYPT_HEADROOM);
/* copy control information */
@@ -882,6 +887,7 @@
pos += fraglen;
}
+ /* adjust first fragment's length */
skb->len = hdrlen + per_fragm;
return 0;
}
@@ -896,6 +902,10 @@
int hdrlen;
int fragnum;
+ /* no matter what happens, tx->skb moves to tx->skbs */
+ __skb_queue_tail(&tx->skbs, skb);
+ tx->skb = NULL;
+
if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
return TX_CONTINUE;
@@ -924,21 +934,21 @@
* of the fragments then we will simply pretend to accept the skb
* but store it away as pending.
*/
- if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
+ if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
return TX_DROP;
/* update duration/seq/flags of fragments */
fragnum = 0;
- do {
+
+ skb_queue_walk(&tx->skbs, skb) {
int next_len;
const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
hdr = (void *)skb->data;
info = IEEE80211_SKB_CB(skb);
- if (skb->next) {
+ if (!skb_queue_is_last(&tx->skbs, skb)) {
hdr->frame_control |= morefrags;
- next_len = skb->next->len;
/*
* No multi-rate retries for fragmented frames, that
* would completely throw off the NAV at other STAs.
@@ -953,10 +963,9 @@
hdr->frame_control &= ~morefrags;
next_len = 0;
}
- hdr->duration_id = ieee80211_duration(tx, 0, next_len);
hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
fragnum++;
- } while ((skb = skb->next));
+ }
return TX_CONTINUE;
}
@@ -964,16 +973,16 @@
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
+ struct sk_buff *skb;
if (!tx->sta)
return TX_CONTINUE;
tx->sta->tx_packets++;
- do {
+ skb_queue_walk(&tx->skbs, skb) {
tx->sta->tx_fragments++;
tx->sta->tx_bytes += skb->len;
- } while ((skb = skb->next));
+ }
return TX_CONTINUE;
}
@@ -1012,21 +1021,25 @@
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
+ struct sk_buff *skb;
struct ieee80211_hdr *hdr;
int next_len;
bool group_addr;
- do {
+ skb_queue_walk(&tx->skbs, skb) {
hdr = (void *) skb->data;
if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
break; /* must not overwrite AID */
- next_len = skb->next ? skb->next->len : 0;
+ if (!skb_queue_is_last(&tx->skbs, skb)) {
+ struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
+ next_len = next->len;
+ } else
+ next_len = 0;
group_addr = is_multicast_ether_addr(hdr->addr1);
hdr->duration_id =
- ieee80211_duration(tx, group_addr, next_len);
- } while ((skb = skb->next));
+ ieee80211_duration(tx, skb, group_addr, next_len);
+ }
return TX_CONTINUE;
}
@@ -1105,6 +1118,7 @@
tx->local = local;
tx->sdata = sdata;
tx->channel = local->hw.conf.channel;
+ __skb_queue_head_init(&tx->skbs);
/*
* If this flag is set to true anywhere, and we get here,
@@ -1180,17 +1194,18 @@
/*
* Returns false if the frame couldn't be transmitted but was queued instead.
*/
-static bool __ieee80211_tx(struct ieee80211_local *local, struct sk_buff **skbp,
+static bool __ieee80211_tx(struct ieee80211_local *local,
+ struct sk_buff_head *skbs,
struct sta_info *sta, bool txpending)
{
- struct sk_buff *skb = *skbp, *next;
+ struct sk_buff *skb, *tmp;
struct ieee80211_tx_info *info;
struct ieee80211_sub_if_data *sdata;
unsigned long flags;
int len;
bool fragm = false;
- while (skb) {
+ skb_queue_walk_safe(skbs, skb, tmp) {
int q = skb_get_queue_mapping(skb);
__le16 fc;
@@ -1202,24 +1217,10 @@
* transmission from the tx-pending tasklet when the
* queue is woken again.
*/
-
- do {
- next = skb->next;
- skb->next = NULL;
- /*
- * NB: If txpending is true, next must already
- * be NULL since we must've gone through this
- * loop before already; therefore we can just
- * queue the frame to the head without worrying
- * about reordering of fragments.
- */
- if (unlikely(txpending))
- __skb_queue_head(&local->pending[q],
- skb);
- else
- __skb_queue_tail(&local->pending[q],
- skb);
- } while ((skb = next));
+ if (txpending)
+ skb_queue_splice(skbs, &local->pending[q]);
+ else
+ skb_queue_splice_tail(skbs, &local->pending[q]);
spin_unlock_irqrestore(&local->queue_stop_reason_lock,
flags);
@@ -1233,10 +1234,9 @@
info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
IEEE80211_TX_CTL_FIRST_FRAGMENT);
- next = skb->next;
len = skb->len;
- if (next)
+ if (!skb_queue_is_last(skbs, skb))
info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
sdata = vif_to_sdata(info->control.vif);
@@ -1260,14 +1260,17 @@
info->control.sta = NULL;
fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
+
+ __skb_unlink(skb, skbs);
drv_tx(local, skb);
ieee80211_tpt_led_trig_tx(local, fc, len);
- *skbp = skb = next;
ieee80211_led_tx(local, 1);
fragm = true;
}
+ WARN_ON(!skb_queue_empty(skbs));
+
return true;
}
@@ -1277,8 +1280,7 @@
*/
static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
- struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
ieee80211_tx_result res = TX_DROP;
#define CALL_TXH(txh) \
@@ -1312,13 +1314,10 @@
txh_done:
if (unlikely(res == TX_DROP)) {
I802_DEBUG_INC(tx->local->tx_handlers_drop);
- while (skb) {
- struct sk_buff *next;
-
- next = skb->next;
- dev_kfree_skb(skb);
- skb = next;
- }
+ if (tx->skb)
+ dev_kfree_skb(tx->skb);
+ else
+ __skb_queue_purge(&tx->skbs);
return -1;
} else if (unlikely(res == TX_QUEUED)) {
I802_DEBUG_INC(tx->local->tx_handlers_queued);
@@ -1361,7 +1360,7 @@
info->band = tx.channel->band;
if (!invoke_tx_handlers(&tx))
- result = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
+ result = __ieee80211_tx(local, &tx.skbs, tx.sta, txpending);
out:
rcu_read_unlock();
return result;
@@ -2109,10 +2108,15 @@
if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
result = ieee80211_tx(sdata, skb, true);
} else {
+ struct sk_buff_head skbs;
+
+ __skb_queue_head_init(&skbs);
+ __skb_queue_tail(&skbs, skb);
+
hdr = (struct ieee80211_hdr *)skb->data;
sta = sta_info_get(sdata, hdr->addr1);
- result = __ieee80211_tx(local, &skb, sta, true);
+ result = __ieee80211_tx(local, &skbs, sta, true);
}
return result;
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 4cf25b0..939bf24 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -95,13 +95,13 @@
void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
+ struct sk_buff *skb;
struct ieee80211_hdr *hdr;
- do {
+ skb_queue_walk(&tx->skbs, skb) {
hdr = (struct ieee80211_hdr *) skb->data;
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
- } while ((skb = skb->next));
+ }
}
int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
diff --git a/net/mac80211/wep.c b/net/mac80211/wep.c
index a1c6bfd..68ad351 100644
--- a/net/mac80211/wep.c
+++ b/net/mac80211/wep.c
@@ -330,13 +330,12 @@
ieee80211_tx_set_protected(tx);
- skb = tx->skb;
- do {
+ skb_queue_walk(&tx->skbs, skb) {
if (wep_encrypt_skb(tx, skb) < 0) {
I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
return TX_DROP;
}
- } while ((skb = skb->next));
+ }
return TX_CONTINUE;
}
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 106e15a..93aab07 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -223,14 +223,14 @@
ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
+ struct sk_buff *skb;
ieee80211_tx_set_protected(tx);
- do {
+ skb_queue_walk(&tx->skbs, skb) {
if (tkip_encrypt_skb(tx, skb) < 0)
return TX_DROP;
- } while ((skb = skb->next));
+ }
return TX_CONTINUE;
}
@@ -449,14 +449,14 @@
ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
+ struct sk_buff *skb;
ieee80211_tx_set_protected(tx);
- do {
+ skb_queue_walk(&tx->skbs, skb) {
if (ccmp_encrypt_skb(tx, skb) < 0)
return TX_DROP;
- } while ((skb = skb->next));
+ }
return TX_CONTINUE;
}
@@ -554,15 +554,22 @@
ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
{
- struct sk_buff *skb = tx->skb;
- struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct sk_buff *skb;
+ struct ieee80211_tx_info *info;
struct ieee80211_key *key = tx->key;
struct ieee80211_mmie *mmie;
u8 aad[20];
u64 pn64;
+ if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
+ return TX_DROP;
+
+ skb = skb_peek(&tx->skbs);
+
+ info = IEEE80211_SKB_CB(skb);
+
if (info->control.hw_key)
- return 0;
+ return TX_CONTINUE;
if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
return TX_DROP;