diff options
Diffstat (limited to 'net/mac80211/tx.c')
| -rw-r--r-- | net/mac80211/tx.c | 97 |
1 files changed, 68 insertions, 29 deletions
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index baa1be0..dac44cb 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1215,6 +1215,45 @@ retry: /* device xmit handlers */ +static int ieee80211_skb_resize(struct ieee80211_local *local, + struct sk_buff *skb, + int head_need, bool may_encrypt) +{ + int tail_need = 0; + + /* + * This could be optimised, devices that do full hardware + * crypto (including TKIP MMIC) need no tailroom... But we + * have no drivers for such devices currently. + */ + if (may_encrypt) { + tail_need = IEEE80211_ENCRYPT_TAILROOM; + tail_need -= skb_tailroom(skb); + tail_need = max_t(int, tail_need, 0); + } + + if (head_need || tail_need) { + /* Sorry. Can't account for this any more */ + skb_orphan(skb); + } + + if (skb_header_cloned(skb)) + I802_DEBUG_INC(local->tx_expand_skb_head_cloned); + else + I802_DEBUG_INC(local->tx_expand_skb_head); + + if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) { + printk(KERN_DEBUG "%s: failed to reallocate TX buffer\n", + wiphy_name(local->hw.wiphy)); + return -ENOMEM; + } + + /* update truesize too */ + skb->truesize += head_need + tail_need; + + return 0; +} + int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev) { @@ -1222,6 +1261,7 @@ int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *odev = NULL; struct ieee80211_sub_if_data *osdata; int headroom; + bool may_encrypt; int ret; if (info->control.ifindex) @@ -1241,13 +1281,18 @@ int ieee80211_master_start_xmit(struct sk_buff *skb, osdata = IEEE80211_DEV_TO_SUB_IF(odev); - headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM; - if (skb_headroom(skb) < headroom) { - if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) { - dev_kfree_skb(skb); - dev_put(odev); - return 0; - } + may_encrypt = !(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT); + + headroom = osdata->local->tx_headroom; + if (may_encrypt) + headroom += IEEE80211_ENCRYPT_HEADROOM; + headroom -= skb_headroom(skb); + headroom = max_t(int, 0, headroom); + + if (ieee80211_skb_resize(osdata->local, skb, headroom, may_encrypt)) { + dev_kfree_skb(skb); + dev_put(odev); + return 0; } info->control.vif = &osdata->vif; @@ -1509,32 +1554,26 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb, * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and * alloc_skb() (net/core/skbuff.c) */ - head_need = hdrlen + encaps_len + meshhdrlen + local->tx_headroom; - head_need -= skb_headroom(skb); + head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb); - /* We are going to modify skb data, so make a copy of it if happens to - * be cloned. This could happen, e.g., with Linux bridge code passing - * us broadcast frames. */ + /* + * So we need to modify the skb header and hence need a copy of + * that. The head_need variable above doesn't, so far, include + * the needed header space that we don't need right away. If we + * can, then we don't reallocate right now but only after the + * frame arrives at the master device (if it does...) + * + * If we cannot, however, then we will reallocate to include all + * the ever needed space. Also, if we need to reallocate it anyway, + * make it big enough for everything we may ever need. + */ if (head_need > 0 || skb_header_cloned(skb)) { -#if 0 - printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes " - "of headroom\n", dev->name, head_need); -#endif - - if (skb_header_cloned(skb)) - I802_DEBUG_INC(local->tx_expand_skb_head_cloned); - else - I802_DEBUG_INC(local->tx_expand_skb_head); - /* Since we have to reallocate the buffer, make sure that there - * is enough room for possible WEP IV/ICV and TKIP (8 bytes - * before payload and 12 after). */ - if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8), - 12, GFP_ATOMIC)) { - printk(KERN_DEBUG "%s: failed to reallocate TX buffer" - "\n", dev->name); + head_need += IEEE80211_ENCRYPT_HEADROOM; + head_need += local->tx_headroom; + head_need = max_t(int, 0, head_need); + if (ieee80211_skb_resize(local, skb, head_need, true)) goto fail; - } } if (encaps_data) { |