Hi Simon,
I am missing a proper commit message with explanation here. One-line subject online commit message are really only ever acceptable if it is a dead trivial fix. And even then I prefer a proper commit message with detailed explanation what the patch changes and why.
> Signed-off-by: Simon Vincent <simon.vincent@xxxxxxxxxx>
> ---
> net/ieee802154/6lowpan_rtnl.c | 131 +++++++++++++++++++++++++++++++-----------
> 1 file changed, 97 insertions(+), 35 deletions(-)
>
> diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c
> index 6591d27..cb94504 100644
> --- a/net/ieee802154/6lowpan_rtnl.c
> +++ b/net/ieee802154/6lowpan_rtnl.c
> @@ -71,6 +71,26 @@ struct lowpan_dev_record {
> struct list_head list;
> };
>
> +union lowpan_addr_u {
> + /* IPv6 needs big endian here */
> + __be64 extended;
> + __be16 short_;
I do not like short_ as field name. I know why you are doing this, but why bother. You always access via u.short anyway. Then again, it seems it is not used at all.
> +};
> +
> +/* don't save pan id, it's intra pan */
> +struct lowpan_addr {
> + /* non converted address mode bits here
> + * make this at first, improve memcmp on this struct
> + */
> + __le16 mode;
> + union lowpan_addr_u u;
If you do not need the union declaration by itself then you can just add it into the struct directly. No need for these extra _u declaration.
> +};
> +
> +struct lowpan_addr_info {
> + struct lowpan_addr daddr;
> + struct lowpan_addr saddr;
> +};
> +
> static inline struct
> lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
> {
> @@ -85,14 +104,21 @@ static inline void lowpan_address_flip(u8 *src, u8 *dest)
> (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
> }
>
> +static inline struct
> +lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
> +{
> + WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
> + return (struct lowpan_addr_info *)(skb->data -
> + sizeof(struct lowpan_addr_info));
> +}
> +
> static int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
> unsigned short type, const void *_daddr,
> const void *_saddr, unsigned int len)
> {
> const u8 *saddr = _saddr;
> const u8 *daddr = _daddr;
> - struct ieee802154_addr sa, da;
> - struct ieee802154_mac_cb *cb = mac_cb_init(skb);
> + struct lowpan_addr_info *info;
>
> /* TODO:
> * if this package isn't ipv6 one, where should it be routed?
> @@ -106,41 +132,15 @@ static int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
> raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
> raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
>
> - lowpan_header_compress(skb, dev, type, daddr, saddr, len);
> -
> - /* NOTE1: I'm still unsure about the fact that compression and WPAN
> - * header are created here and not later in the xmit. So wait for
> - * an opinion of net maintainers.
> - */
> - /* NOTE2: to be absolutely correct, we must derive PANid information
> - * from MAC subif of the 'dev' and 'real_dev' network devices, but
> - * this isn't implemented in mainline yet, so currently we assign 0xff
> - */
> - cb->type = IEEE802154_FC_TYPE_DATA;
> -
> - /* prepare wpan address data */
> - sa.mode = IEEE802154_ADDR_LONG;
> - sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
> - sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
> + info = lowpan_skb_priv(skb);
>
> - /* intra-PAN communications */
> - da.pan_id = sa.pan_id;
> + info->daddr.mode = IEEE802154_ADDR_LONG;
> + memcpy(&info->daddr.u.extended, daddr, sizeof(info->daddr.u.extended));
>
> - /* if the destination address is the broadcast address, use the
> - * corresponding short address
> - */
> - if (lowpan_is_addr_broadcast(daddr)) {
> - da.mode = IEEE802154_ADDR_SHORT;
> - da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
> - } else {
> - da.mode = IEEE802154_ADDR_LONG;
> - da.extended_addr = ieee802154_devaddr_from_raw(daddr);
> - }
> + info->saddr.mode = IEEE802154_ADDR_LONG;
> + memcpy(&info->saddr.u.extended, saddr, sizeof(info->daddr.u.extended));
>
> - cb->ackreq = !lowpan_is_addr_broadcast(daddr);
> -
> - return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
> - type, (void *)&da, (void *)&sa, 0);
> + return 0;
> }
>
> static int lowpan_give_skb_to_devices(struct sk_buff *skb,
> @@ -338,13 +338,74 @@ err:
> return rc;
> }
>
> +static int lowpan_header(struct sk_buff *skb, struct net_device *dev)
> +{
> + struct ieee802154_addr sa, da;
> + struct ieee802154_mac_cb *cb = mac_cb_init(skb);
> + struct lowpan_addr_info info;
> + void *daddr, *saddr;
> +
> + memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
> +
> + /* TODO complicated bug why we support extended_addr only */
This is not a good comment. Explain why since especially only extended addresses are supported, I have no idea on why we are adding all these struct addition in the first place.
> + daddr = &info.daddr.u.extended;
> + saddr = &info.saddr.u.extended;
> +
> + lowpan_header_compress(skb, dev, ETH_P_IPV6, daddr, saddr, skb->len);
> +
> + /* NOTE1: I'm still unsure about the fact that compression and WPAN
> + * header are created here and not later in the xmit. So wait for
> + * an opinion of net maintainers.
> + */
Now I wonder why this has not yet been answered and you are in the need of copying around. Maybe this should have been addressed by now.
> + /* NOTE2: to be absolutely correct, we must derive PANid information
> + * from MAC subif of the 'ldev' and 'wdev' network devices, but
> + * this isn't implemented in mainline yet, so currently we assign 0xff
> + */
> + cb->type = IEEE802154_FC_TYPE_DATA;
> +
> + /* prepare wpan address data */
> + sa.mode = IEEE802154_ADDR_LONG;
> + sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
> + sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
> +
> + /* intra-PAN communications */
> + da.pan_id = sa.pan_id;
> +
> + /* if the destination address is the broadcast address, use the
> + * corresponding short address
> + */
> + if (lowpan_is_addr_broadcast((const u8 *)daddr)) {
> + da.mode = IEEE802154_ADDR_SHORT;
> + da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
> + cb->ackreq = false;
> + } else {
> + da.mode = IEEE802154_ADDR_LONG;
> + da.extended_addr = ieee802154_devaddr_from_raw(daddr);
> + cb->ackreq = true;
> + }
> +
> + return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
> + ETH_P_IPV6, (void *)&da, (void *)&sa, 0);
> +}
> +
> static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> struct ieee802154_hdr wpan_hdr;
> - int max_single;
> + int max_single, ret;
>
> pr_debug("package xmit\n");
>
> + /* We must take a copy of the skb before we modify/replace the ipv6
> + * header as the header could be used elsewhere
> + */
> + skb = skb_unshare(skb, GFP_KERNEL);
> +
> + ret = lowpan_header(skb, dev);
> + if (ret < 0) {
> + kfree_skb(skb);
> + return NET_XMIT_DROP;
> + }
> +
> if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
> kfree_skb(skb);
> return NET_XMIT_DROP;
Regards
Marcel
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