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| author | Martin Townsend <mtownsend1973@gmail.com> | 2014-10-13 14:00:56 +0400 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2014-10-25 09:56:25 +0400 |
| commit | 11e3ff7072789ad4585870cbdde1be10c45f1cc4 (patch) | |
| tree | 0a8e62cbf7eaeb33ac5931f9cea2321abf730ce5 /net/6lowpan/iphc.c | |
| parent | 4456c50d23d44352f4174a9a0cb75313d3150907 (diff) | |
| download | linux-11e3ff7072789ad4585870cbdde1be10c45f1cc4.tar.xz | |
6lowpan: Use skb_cow in IPHC decompression.
Currently there are potentially 2 skb_copy_expand calls in IPHC
decompression. This patch replaces this with one call to
skb_cow which will check to see if there is enough headroom
first to ensure it's only done if necessary and will handle
alignment issues for cache.
As skb_cow uses pskb_expand_head we ensure the skb isn't shared from
bluetooth and ieee802.15.4 code that use the IPHC decompression.
Signed-off-by: Martin Townsend <martin.townsend@xsilon.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/6lowpan/iphc.c')
| -rw-r--r-- | net/6lowpan/iphc.c | 47 |
1 files changed, 21 insertions, 26 deletions
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c index 142eef55c9e2..747b3ccfc4f8 100644 --- a/net/6lowpan/iphc.c +++ b/net/6lowpan/iphc.c @@ -174,30 +174,22 @@ static int uncompress_context_based_src_addr(struct sk_buff *skb, static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr, struct net_device *dev, skb_delivery_cb deliver_skb) { - struct sk_buff *new; int stat; - new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb), - GFP_ATOMIC); - kfree_skb(skb); - - if (!new) - return -ENOMEM; - - skb_push(new, sizeof(struct ipv6hdr)); - skb_reset_network_header(new); - skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr)); + skb_push(skb, sizeof(struct ipv6hdr)); + skb_reset_network_header(skb); + skb_copy_to_linear_data(skb, hdr, sizeof(struct ipv6hdr)); - new->protocol = htons(ETH_P_IPV6); - new->pkt_type = PACKET_HOST; - new->dev = dev; + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; + skb->dev = dev; raw_dump_table(__func__, "raw skb data dump before receiving", - new->data, new->len); + skb->data, skb->len); - stat = deliver_skb(new, dev); + stat = deliver_skb(skb, dev); - kfree_skb(new); + consume_skb(skb); return stat; } @@ -460,7 +452,7 @@ int lowpan_process_data(struct sk_buff *skb, struct net_device *dev, /* UDP data uncompression */ if (iphc0 & LOWPAN_IPHC_NH_C) { struct udphdr uh; - struct sk_buff *new; + const int needed = sizeof(struct udphdr) + sizeof(hdr); if (uncompress_udp_header(skb, &uh)) goto drop; @@ -468,14 +460,11 @@ int lowpan_process_data(struct sk_buff *skb, struct net_device *dev, /* replace the compressed UDP head by the uncompressed UDP * header */ - new = skb_copy_expand(skb, sizeof(struct udphdr), - skb_tailroom(skb), GFP_ATOMIC); - kfree_skb(skb); - - if (!new) - return -ENOMEM; - - skb = new; + err = skb_cow(skb, needed); + if (unlikely(err)) { + kfree_skb(skb); + return err; + } skb_push(skb, sizeof(struct udphdr)); skb_reset_transport_header(skb); @@ -485,6 +474,12 @@ int lowpan_process_data(struct sk_buff *skb, struct net_device *dev, (u8 *)&uh, sizeof(uh)); hdr.nexthdr = UIP_PROTO_UDP; + } else { + err = skb_cow(skb, sizeof(hdr)); + if (unlikely(err)) { + kfree_skb(skb); + return err; + } } hdr.payload_len = htons(skb->len); |