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From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 2 Feb 2016 14:39:10 +0100
Subject: [PATCH] cfg80211: add support for non-linear skbs in
ieee80211_amsdu_to_8023s
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -644,73 +644,75 @@ int ieee80211_data_from_8023(struct sk_b
}
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, ð, 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, ð, 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_
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)), ð, sizeof(eth));
__skb_queue_tail(list, frame);
}
+ if (!reuse_skb)
+ dev_kfree_skb(skb);
+
return;
purge:
|
