On Tue, Sep 16, 2014 at 12:01:59PM +0100, Martin Townsend wrote:
> Currently there are a number of error paths in the lowpan_rcv function that
> free the skb before returning, the patch simplifies the receive path by
> ensuring that the skb is only freed from this function.
>
> Passing the skb from 6lowpan up to the higher layers is not a
> function of IPHC. By moving it out of IPHC we also remove the
> need to support error code returns with NET_RX codes.
> It also makes the lowpan_rcv function more extendable as we
> can support more compression schemes.
>
> With the above 2 lowpan_rcv is refacored so eliminate incorrect return values.
>
> Signed-off-by: Martin Townsend <martin.towns...@xsilon.com>
> ---
> include/net/6lowpan.h | 9 +++--
> net/6lowpan/iphc.c | 88
> +++++++++++++++++--------------------------
> net/bluetooth/6lowpan.c | 38 ++++++++++---------
> net/ieee802154/6lowpan_rtnl.c | 61 ++++++++++++++++--------------
> 4 files changed, 94 insertions(+), 102 deletions(-)
>
> diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
> index d184df1..c28fadb 100644
> --- a/include/net/6lowpan.h
> +++ b/include/net/6lowpan.h
...
> -static int process_data(struct sk_buff *skb, struct net_device *netdev,
> - struct l2cap_chan *chan)
> +static struct sk_buff *
> +process_data(struct sk_buff *skb, struct net_device *netdev,
> + struct l2cap_chan *chan)
> {
> const u8 *saddr, *daddr;
> u8 iphc0, iphc1;
> @@ -230,36 +231,31 @@ static int process_data(struct sk_buff *skb, struct
> net_device *netdev,
> peer = peer_lookup_chan(dev, chan);
> read_unlock_irqrestore(&devices_lock, flags);
> if (!peer)
> - goto drop;
> + return ERR_PTR(-EINVAL);
>
> saddr = peer->eui64_addr;
> daddr = dev->netdev->dev_addr;
>
> /* at least two bytes will be used for the encoding */
> if (skb->len < 2)
> - goto drop;
> + return ERR_PTR(-EINVAL);
>
> if (lowpan_fetch_skb_u8(skb, &iphc0))
> - goto drop;
> + return ERR_PTR(-EINVAL);
>
> if (lowpan_fetch_skb_u8(skb, &iphc1))
> - goto drop;
> + return ERR_PTR(-EINVAL);
>
> return lowpan_process_data(skb, netdev,
> saddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
> daddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
> - iphc0, iphc1, give_skb_to_upper);
> -
> -drop:
> - kfree_skb(skb);
> - return -EINVAL;
> + iphc0, iphc1);
> }
>
> static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
> struct l2cap_chan *chan)
> {
> struct sk_buff *local_skb;
> - int ret;
>
> if (!netif_running(dev))
> goto drop;
> @@ -280,9 +276,6 @@ static int recv_pkt(struct sk_buff *skb, struct
> net_device *dev,
> local_skb->protocol = htons(ETH_P_IPV6);
> local_skb->pkt_type = PACKET_HOST;
>
> - skb_reset_network_header(local_skb);
> - skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
> -
> if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
> kfree_skb(local_skb);
> goto drop;
> @@ -300,9 +293,20 @@ static int recv_pkt(struct sk_buff *skb, struct
> net_device *dev,
> if (!local_skb)
> goto drop;
>
> - ret = process_data(local_skb, dev, chan);
> - if (ret != NET_RX_SUCCESS)
> + skb = process_data(local_skb, dev, chan);
> + if (IS_ERR(skb)) {
> + kfree_skb(local_skb);
> goto drop;
> + }
> +
> + local_skb->protocol = htons(ETH_P_IPV6);
> + local_skb->pkt_type = PACKET_HOST;
this is the wrong skb here, the new one is skb. I don't know maybe there
is some optimization to call skb = process_data(skb, ...);
> +
> + if (give_skb_to_upper(local_skb, dev)
also here local_skb should be skb, or?
- Alex
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