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cfg80211: add function for 802.3 conversion with separate output buffer
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Use skb_copy_bits in preparation for allowing fragmented skbs

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Felix Fietkau authored and Johannes Berg committed Feb 24, 2016
1 parent 88665f5 commit 2d1c304
Showing 1 changed file with 53 additions and 53 deletions.
106 changes: 53 additions & 53 deletions net/wireless/util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -393,9 +393,9 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
static unsigned int __ieee80211_get_mesh_hdrlen(u8 flags)
{
int ae = meshhdr->flags & MESH_FLAGS_AE;
int ae = flags & MESH_FLAGS_AE;
/* 802.11-2012, 8.2.4.7.3 */
switch (ae) {
default:
Expand All @@ -407,21 +407,31 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
return 18;
}
}

unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
{
return __ieee80211_get_mesh_hdrlen(meshhdr->flags);
}
EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);

int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
enum nl80211_iftype iftype)
static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr,
const u8 *addr, enum nl80211_iftype iftype)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u16 hdrlen, ethertype;
u8 *payload;
u8 dst[ETH_ALEN];
u8 src[ETH_ALEN] __aligned(2);
struct {
u8 hdr[ETH_ALEN] __aligned(2);
__be16 proto;
} payload;
struct ethhdr tmp;
u16 hdrlen;
u8 mesh_flags = 0;

if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
return -1;

hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (skb->len < hdrlen + 8)
return -1;

/* convert IEEE 802.11 header + possible LLC headers into Ethernet
* header
Expand All @@ -432,8 +442,11 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
* 1 0 BSSID SA DA n/a
* 1 1 RA TA DA SA
*/
memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
memcpy(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN);

if (iftype == NL80211_IFTYPE_MESH_POINT)
skb_copy_bits(skb, hdrlen, &mesh_flags, 1);

switch (hdr->frame_control &
cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
Expand All @@ -450,44 +463,31 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
iftype != NL80211_IFTYPE_STATION))
return -1;
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
/* make sure meshdr->flags is on the linear part */
if (!pskb_may_pull(skb, hdrlen + 1))
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A4)
if (mesh_flags & MESH_FLAGS_AE_A4)
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
if (mesh_flags & MESH_FLAGS_AE_A5_A6) {
skb_copy_bits(skb, hdrlen +
offsetof(struct ieee80211s_hdr, eaddr1),
dst, ETH_ALEN);
skb_copy_bits(skb, hdrlen +
offsetof(struct ieee80211s_hdr, eaddr2),
src, ETH_ALEN);
tmp.h_dest, 2 * ETH_ALEN);
}
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
}
break;
case cpu_to_le16(IEEE80211_FCTL_FROMDS):
if ((iftype != NL80211_IFTYPE_STATION &&
iftype != NL80211_IFTYPE_P2P_CLIENT &&
iftype != NL80211_IFTYPE_MESH_POINT) ||
(is_multicast_ether_addr(dst) &&
ether_addr_equal(src, addr)))
(is_multicast_ether_addr(tmp.h_dest) &&
ether_addr_equal(tmp.h_source, addr)))
return -1;
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
/* make sure meshdr->flags is on the linear part */
if (!pskb_may_pull(skb, hdrlen + 1))
if (mesh_flags & MESH_FLAGS_AE_A5_A6)
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A5_A6)
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A4)
if (mesh_flags & MESH_FLAGS_AE_A4)
skb_copy_bits(skb, hdrlen +
offsetof(struct ieee80211s_hdr, eaddr1),
src, ETH_ALEN);
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
tmp.h_source, ETH_ALEN);
hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
}
break;
case cpu_to_le16(0):
Expand All @@ -498,33 +498,33 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
break;
}

if (!pskb_may_pull(skb, hdrlen + 8))
return -1;

payload = skb->data + hdrlen;
ethertype = (payload[6] << 8) | payload[7];
skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
tmp.h_proto = payload.proto;

if (likely((ether_addr_equal(payload, rfc1042_header) &&
ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
ether_addr_equal(payload, bridge_tunnel_header))) {
if (likely((ether_addr_equal(payload.hdr, rfc1042_header) &&
tmp.h_proto != htons(ETH_P_AARP) &&
tmp.h_proto != htons(ETH_P_IPX)) ||
ether_addr_equal(payload.hdr, bridge_tunnel_header)))
/* remove RFC1042 or Bridge-Tunnel encapsulation and
* replace EtherType */
skb_pull(skb, hdrlen + 6);
memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
} else {
struct ethhdr *ehdr;
__be16 len;
hdrlen += ETH_ALEN + 2;
else
tmp.h_proto = htons(skb->len);

pskb_pull(skb, hdrlen);

skb_pull(skb, hdrlen);
len = htons(skb->len);
if (!ehdr)
ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
memcpy(ehdr->h_dest, dst, ETH_ALEN);
memcpy(ehdr->h_source, src, ETH_ALEN);
ehdr->h_proto = len;
}
memcpy(ehdr, &tmp, sizeof(tmp));

return 0;
}

int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
enum nl80211_iftype iftype)
{
return __ieee80211_data_to_8023(skb, NULL, addr, iftype);
}
EXPORT_SYMBOL(ieee80211_data_to_8023);

int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
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