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cfg80211: add support for non-linear skbs in ieee80211_amsdu_to_8023s

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Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Felix Fietkau 2016-02-02 14:39:10 +01:00 committed by Johannes Berg
parent 2d1c304cb2
commit 230fd28a91
1 changed files with 49 additions and 51 deletions
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100
net/wireless/util.c
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@ -644,73 +644,75 @@ int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
}
EXPORT_SYMBOL(ieee80211_data_from_8023);
static struct sk_buff *
__ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen,
int offset, int len)
{
struct sk_buff *frame;
if (skb->len - offset < len)
return NULL;
/*
* Allocate and reserve two bytes more for payload
* alignment since sizeof(struct ethhdr) is 14.
*/
frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + len);
skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
skb_copy_bits(skb, offset, skb_put(frame, len), len);
return frame;
}
void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
const u8 *addr, enum nl80211_iftype iftype,
const unsigned int extra_headroom,
bool has_80211_header)
{
unsigned int hlen = ALIGN(extra_headroom, 4);
struct sk_buff *frame = NULL;
u16 ethertype;
u8 *payload;
const struct ethhdr *eth;
int remaining, err;
u8 dst[ETH_ALEN], src[ETH_ALEN];
if (skb_linearize(skb))
goto out;
int offset = 0, remaining, err;
struct ethhdr eth;
bool reuse_skb = true;
bool last = false;
if (has_80211_header) {
err = ieee80211_data_to_8023(skb, addr, iftype);
err = __ieee80211_data_to_8023(skb, &eth, addr, iftype);
if (err)
goto out;
/* skip the wrapping header */
eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
if (!eth)
goto out;
} else {
eth = (struct ethhdr *) skb->data;
}
while (skb != frame) {
while (!last) {
unsigned int subframe_len;
int len;
u8 padding;
__be16 len = eth->h_proto;
unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
remaining = skb->len;
memcpy(dst, eth->h_dest, ETH_ALEN);
memcpy(src, eth->h_source, ETH_ALEN);
skb_copy_bits(skb, offset, &eth, sizeof(eth));
len = ntohs(eth.h_proto);
subframe_len = sizeof(struct ethhdr) + len;
padding = (4 - subframe_len) & 0x3;
/* the last MSDU has no padding */
remaining = skb->len - offset;
if (subframe_len > remaining)
goto purge;
skb_pull(skb, sizeof(struct ethhdr));
offset += sizeof(struct ethhdr);
/* reuse skb for the last subframe */
if (remaining <= subframe_len + padding)
last = remaining <= subframe_len + padding;
if (!skb_is_nonlinear(skb) && last) {
skb_pull(skb, offset);
frame = skb;
else {
unsigned int hlen = ALIGN(extra_headroom, 4);
/*
* Allocate and reserve two bytes more for payload
* alignment since sizeof(struct ethhdr) is 14.
*/
frame = dev_alloc_skb(hlen + subframe_len + 2);
reuse_skb = true;
} else {
frame = __ieee80211_amsdu_copy(skb, hlen, offset, len);
if (!frame)
goto purge;
skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
memcpy(skb_put(frame, ntohs(len)), skb->data,
ntohs(len));
eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
padding);
if (!eth) {
dev_kfree_skb(frame);
goto purge;
}
offset += len + padding;
}
skb_reset_network_header(frame);
@ -719,24 +721,20 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
payload = frame->data;
ethertype = (payload[6] << 8) | payload[7];
if (likely((ether_addr_equal(payload, rfc1042_header) &&
ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
ether_addr_equal(payload, bridge_tunnel_header))) {
/* remove RFC1042 or Bridge-Tunnel
* encapsulation and replace EtherType */
skb_pull(frame, 6);
memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
} else {
memcpy(skb_push(frame, sizeof(__be16)), &len,
sizeof(__be16));
memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
eth.h_proto = htons(ethertype);
skb_pull(frame, ETH_ALEN + 2);
}
memcpy(skb_push(frame, sizeof(eth)), &eth, sizeof(eth));
__skb_queue_tail(list, frame);
}
if (!reuse_skb)
dev_kfree_skb(skb);
return;
purge: