Re: [RFCv2 bluetooth-next 16/16] ieee802154: 6lowpan: remove tx full-size calc workaround

[Stefan Schmidt <stefan@osg.samsung.com>]

Hello.

On 31/08/15 00:06, Stefan Schmidt wrote:
> Hello.
>
> On 20/08/15 18:47, Alexander Aring wrote:
>> This patch removes a workaround for datagram_size calculation while
>> doing fragmentation on transmit.
>>
>> Signed-off-by: Alexander Aring <alex.aring@gmail.com>
>> ---
>>   include/net/6lowpan.h       | 113 
>> --------------------------------------------
>>   net/ieee802154/6lowpan/tx.c |  18 ++++---
>>   2 files changed, 11 insertions(+), 120 deletions(-)
>>
>> diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
>> index 3509841..eeae5eb 100644
>> --- a/include/net/6lowpan.h
>> +++ b/include/net/6lowpan.h
>> @@ -299,119 +299,6 @@ static inline void lowpan_push_hc_data(u8 
>> **hc_ptr, const void *data,
>>       *hc_ptr += len;
>>   }
>>   -static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
>> -{
>> -    static const u8 addr_sizes[] = {
>> -        [LOWPAN_IPHC_ADDR_00] = 16,
>> -        [LOWPAN_IPHC_ADDR_01] = 8,
>> -        [LOWPAN_IPHC_ADDR_02] = 2,
>> -        [LOWPAN_IPHC_ADDR_03] = 0,
>> -    };
>> -    return addr_sizes[addr_mode];
>> -}
>> -
>> -static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 
>> *uncomp_header)
>> -{
>> -    u8 ret = 1;
>> -
>> -    if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
>> -        *uncomp_header += sizeof(struct udphdr);
>> -
>> -        switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
>> -        case LOWPAN_NHC_UDP_CS_P_00:
>> -            ret += 4;
>> -            break;
>> -        case LOWPAN_NHC_UDP_CS_P_01:
>> -        case LOWPAN_NHC_UDP_CS_P_10:
>> -            ret += 3;
>> -            break;
>> -        case LOWPAN_NHC_UDP_CS_P_11:
>> -            ret++;
>> -            break;
>> -        default:
>> -            break;
>> -        }
>> -
>> -        if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
>> -            ret += 2;
>> -    }
>> -
>> -    return ret;
>> -}
>> -
>> -/**
>> - *    lowpan_uncompress_size - returns skb->len size with 
>> uncompressed header
>> - *    @skb: sk_buff with 6lowpan header inside
>> - *    @datagram_offset: optional to get the datagram_offset value
>> - *
>> - *    Returns the skb->len with uncompressed header
>> - */
>> -static inline u16
>> -lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
>> -{
>> -    u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
>> -    u8 iphc0, iphc1, h_enc;
>> -
>> -    iphc0 = skb_network_header(skb)[0];
>> -    iphc1 = skb_network_header(skb)[1];
>> -
>> -    switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
>> -    case 0:
>> -        ret += 4;
>> -        break;
>> -    case 1:
>> -        ret += 3;
>> -        break;
>> -    case 2:
>> -        ret++;
>> -        break;
>> -    default:
>> -        break;
>> -    }
>> -
>> -    if (!(iphc0 & LOWPAN_IPHC_NH_C))
>> -        ret++;
>> -
>> -    if (!(iphc0 & 0x03))
>> -        ret++;
>> -
>> -    ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
>> -                     LOWPAN_IPHC_SAM_BIT);
>> -
>> -    if (iphc1 & LOWPAN_IPHC_M) {
>> -        switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
>> -            LOWPAN_IPHC_DAM_BIT) {
>> -        case LOWPAN_IPHC_DAM_00:
>> -            ret += 16;
>> -            break;
>> -        case LOWPAN_IPHC_DAM_01:
>> -            ret += 6;
>> -            break;
>> -        case LOWPAN_IPHC_DAM_10:
>> -            ret += 4;
>> -            break;
>> -        case LOWPAN_IPHC_DAM_11:
>> -            ret++;
>> -            break;
>> -        default:
>> -            break;
>> -        }
>> -    } else {
>> -        ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
>> -                         LOWPAN_IPHC_DAM_BIT);
>> -    }
>> -
>> -    if (iphc0 & LOWPAN_IPHC_NH_C) {
>> -        h_enc = skb_network_header(skb)[ret];
>> -        ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
>> -    }
>> -
>> -    if (dgram_offset)
>> -        *dgram_offset = uncomp_header;
>> -
>> -    return skb->len + uncomp_header - ret;
>> -}
>> -
>>   void lowpan_netdev_setup(struct net_device *dev, enum 
>> lowpan_lltypes lltype);
>>     int
>> diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
>> index 9a2147e..4115335 100644
>> --- a/net/ieee802154/6lowpan/tx.c
>> +++ b/net/ieee802154/6lowpan/tx.c
>> @@ -123,16 +123,14 @@ lowpan_xmit_fragment(struct sk_buff *skb, const 
>> struct ieee802154_hdr *wpan_hdr,
>>     static int
>>   lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
>> -               const struct ieee802154_hdr *wpan_hdr)
>> +               const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
>> +               u16 dgram_offset)
>>   {
>> -    u16 dgram_size, dgram_offset;
>>       __be16 frag_tag;
>>       u8 frag_hdr[5];
>>       int frag_cap, frag_len, payload_cap, rc;
>>       int skb_unprocessed, skb_offset;
>>   -    dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
>> -             skb->mac_len;
>>       frag_tag = htons(lowpan_dev_info(ldev)->fragment_tag);
>>       lowpan_dev_info(ldev)->fragment_tag++;
>>   @@ -187,7 +185,8 @@ err:
>>       return rc;
>>   }
>>   -static int lowpan_header(struct sk_buff *skb, struct net_device 
>> *ldev)
>> +static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
>> +             u16 *dgram_size, u16 *dgram_offset)
>>   {
>>       struct wpan_dev *wpan_dev = 
>> lowpan_dev_info(ldev)->wdev->ieee802154_ptr;
>>       struct ieee802154_addr sa, da;
>> @@ -201,7 +200,10 @@ static int lowpan_header(struct sk_buff *skb, 
>> struct net_device *ldev)
>>       daddr = &info.daddr.u.extended_addr;
>>       saddr = &info.saddr.u.extended_addr;
>>   +    *dgram_size = skb->len;
>>       lowpan_header_compress(skb, ldev, ETH_P_IPV6, daddr, saddr, 
>> skb->len);
>> +    /* dgram_size = (saved bytes after compression) + lowpan header 
>> size */
>> +    *dgram_offset = (*dgram_size - skb->len) + 
>> skb_network_header_len(skb);
>>         cb->type = IEEE802154_FC_TYPE_DATA;
>>   @@ -234,6 +236,7 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, 
>> struct net_device *ldev)
>>   {
>>       struct ieee802154_hdr wpan_hdr;
>>       int max_single, ret;
>> +    u16 dgram_size, dgram_offset;
>>         pr_debug("package xmit\n");
>>   @@ -244,7 +247,7 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, 
>> struct net_device *ldev)
>>       if (!skb)
>>           return NET_XMIT_DROP;
>>   -    ret = lowpan_header(skb, ldev);
>> +    ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
>>       if (ret < 0) {
>>           kfree_skb(skb);
>>           return NET_XMIT_DROP;
>> @@ -264,7 +267,8 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, 
>> struct net_device *ldev)
>>           netdev_tx_t rc;
>>             pr_debug("frame is too big, fragmentation is needed\n");
>> -        rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr);
>> +        rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
>> +                        dgram_offset);
>>             return rc < 0 ? NET_XMIT_DROP : rc;
>>       }
>
> Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
>

This should also have been

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>

regards
Stefan Schmidt