On Mon, Aug 31, 2015 at 11:28:45AM +0200, Stefan Schmidt wrote:
> Hello.
>
> On 20/08/15 18:47, Alexander Aring wrote:
> >This patch complete reworks the evaluation of 6lowpan dispatch value by
> >introducing a receive handler mechanism for each dispatch value.
> >
> >A list of changes:
> >
> > - Doing uncompression on-the-fly when FRAG1 is received, this require
> > some special handling for 802.15.4 lltype in generic 6lowpan branch
> > for setting the payload length correct.
> > - Fix dispatch mask for fragmentation.
> > - Add IPv6 dispatch evaluation for FRAG1.
> > - Add skb_unshare for dispatch which might manipulate the skb data
> > buffer.
> >
> >Signed-off-by: Alexander Aring <alex.aring@xxxxxxxxx>
> >---
> > include/net/6lowpan.h | 31 ++++--
>
> Not sure if you might want to include Jukka here for the shared header part
> with BT.
Yes, I will do that when sending PATCH. Maybe I should also split this
patch, but I think it's fine. Very small changes.
> > net/6lowpan/iphc.c | 13 ++-
> > net/6lowpan/nhc_udp.c | 13 ++-
> > net/ieee802154/6lowpan/6lowpan_i.h | 12 +++
> > net/ieee802154/6lowpan/reassembly.c | 126 +++++++++++++++++-------
> > net/ieee802154/6lowpan/rx.c | 188 ++++++++++++++++++++++++------------
> > 6 files changed, 278 insertions(+), 105 deletions(-)
> >
> >diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
> >index a2f59ec..3509841 100644
> >--- a/include/net/6lowpan.h
> >+++ b/include/net/6lowpan.h
> >@@ -126,13 +126,19 @@
> > (((a)[6]) == 0xFF) && \
> > (((a)[7]) == 0xFF))
> >-#define LOWPAN_DISPATCH_IPV6 0x41 /* 01000001 = 65 */
> >-#define LOWPAN_DISPATCH_HC1 0x42 /* 01000010 = 66 */
> >-#define LOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx = ... */
> >-#define LOWPAN_DISPATCH_FRAG1 0xc0 /* 11000xxx */
> >-#define LOWPAN_DISPATCH_FRAGN 0xe0 /* 11100xxx */
> >+#define LOWPAN_DISPATCH_IPV6 0x41 /* 01000001 = 65 */
> >+#define LOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx = ... */
> >+#define LOWPAN_DISPATCH_IPHC_MASK 0xe0
> >-#define LOWPAN_DISPATCH_MASK 0xf8 /* 11111000 */
> >+static inline bool lowpan_is_ipv6(u8 dispatch)
> >+{
> >+ return dispatch == LOWPAN_DISPATCH_IPV6;
> >+}
> >+
> >+static inline bool lowpan_is_iphc(u8 dispatch)
> >+{
> >+ return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
> >+}
> > #define LOWPAN_FRAG_TIMEOUT (HZ * 60) /* time-out 60 sec */
> >@@ -218,6 +224,19 @@ struct lowpan_priv *lowpan_priv(const struct net_device *dev)
> > return netdev_priv(dev);
> > }
> >+struct lowpan_802154_cb {
> >+ u16 d_tag;
> >+ unsigned int d_size;
> >+ u8 d_offset;
> >+};
> >+
> >+static inline
> >+struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
> >+{
> >+ BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
> >+ return (struct lowpan_802154_cb *)skb->cb;
> >+}
> >+
> > #ifdef DEBUG
> > /* print data in line */
> > static inline void raw_dump_inline(const char *caller, char *msg,
> >diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
> >index 1e0071f..78c8a49 100644
> >--- a/net/6lowpan/iphc.c
> >+++ b/net/6lowpan/iphc.c
> >@@ -366,7 +366,18 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
> > return err;
> > }
> >- hdr.payload_len = htons(skb->len);
> >+ switch (lowpan_priv(dev)->lltype) {
> >+ case LOWPAN_LLTYPE_IEEE802154:
> >+ if (lowpan_802154_cb(skb)->d_size)
> >+ hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
> >+ sizeof(struct ipv6hdr));
> >+ else
> >+ hdr.payload_len = htons(skb->len);
> >+ break;
> >+ default:
> >+ hdr.payload_len = htons(skb->len);
>
> The default and else block being the same here I think that can be
> simplified.
> >+ break;
> >+ }
> > pr_debug("skb headroom size = %d, data length = %d\n",
> > skb_headroom(skb), skb->len);
> >diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c
> >index c6bcaeb..72d0b57 100644
> >--- a/net/6lowpan/nhc_udp.c
> >+++ b/net/6lowpan/nhc_udp.c
> >@@ -71,7 +71,18 @@ static int udp_uncompress(struct sk_buff *skb, size_t needed)
> > * here, we obtain the hint from the remaining size of the
> > * frame
> > */
> >- uh.len = htons(skb->len + sizeof(struct udphdr));
> >+ switch (lowpan_priv(skb->dev)->lltype) {
> >+ case LOWPAN_LLTYPE_IEEE802154:
> >+ if (lowpan_802154_cb(skb)->d_size)
> >+ uh.len = htons(lowpan_802154_cb(skb)->d_size -
> >+ sizeof(struct ipv6hdr));
> >+ else
> >+ uh.len = htons(skb->len + sizeof(struct udphdr));
> >+ break;
> >+ default:
> >+ uh.len = htons(skb->len + sizeof(struct udphdr));
> >+ break;
> >+ }
>
> Else branch and default case same again.
I see no optimiziation here, what we could do would be a set of "uh.len"
like default case and then overwrite it -> but this confuse other
programmers.
> > pr_debug("uncompressed UDP length: src = %d", ntohs(uh.len));
> > /* replace the compressed UDP head by the uncompressed UDP
> >diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
> >index 9aa7b62..b4e17a7 100644
> >--- a/net/ieee802154/6lowpan/6lowpan_i.h
> >+++ b/net/ieee802154/6lowpan/6lowpan_i.h
> >@@ -7,6 +7,15 @@
> > #include <net/inet_frag.h>
> > #include <net/6lowpan.h>
> >+typedef unsigned __bitwise__ lowpan_rx_result;
> >+#define RX_CONTINUE ((__force lowpan_rx_result) 0u)
> >+#define RX_DROP_UNUSABLE ((__force lowpan_rx_result) 1u)
> >+#define RX_DROP ((__force lowpan_rx_result) 2u)
> >+#define RX_QUEUED ((__force lowpan_rx_result) 3u)
> >+
> >+#define LOWPAN_DISPATCH_FRAG1 0xc0
> >+#define LOWPAN_DISPATCH_FRAGN 0xe0
> >+
> > struct lowpan_create_arg {
> > u16 tag;
> > u16 d_size;
> >@@ -62,4 +71,7 @@ int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
> > const void *_saddr, unsigned int len);
> > netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev);
> >+int lowpan_iphc_decompress(struct sk_buff *skb);
> >+lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb);
> >+
...
> >+}
> >+
> >+static int lowpan_get_cb(struct sk_buff *skb, u8 frag_type,
> >+ struct lowpan_802154_cb *cb)
> > {
> > bool fail;
> > u8 pattern = 0, low = 0;
> >@@ -334,15 +376,19 @@ static int lowpan_get_frag_info(struct sk_buff *skb, const u8 frag_type,
> > fail = lowpan_fetch_skb(skb, &pattern, 1);
> > fail |= lowpan_fetch_skb(skb, &low, 1);
> >- frag_info->d_size = (pattern & 7) << 8 | low;
> >+ cb->d_size = (pattern & 7) << 8 | low;
>
> Magic numbers. Yeah,. I know they have been there before.
ok. Will introduce some define above this function.
- Alex
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