netdev - Re: [PATCH v2 4/4] net: make skb_gso_*

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Date:   Fri, 2 Mar 2018 18:13:17 -0300
From:   Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
To:     Daniel Axtens <dja@...ens.net>
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH v2 4/4] net: make skb_gso_*_seglen functions private

On Thu, Mar 01, 2018 at 05:13:40PM +1100, Daniel Axtens wrote:
> They're very hard to use properly as they do not consider the
> GSO_BY_FRAGS case. Code should use skb_gso_validate_network_len
> and skb_gso_validate_mac_len as they do consider this case.
> 
> Make the seglen functions static, which stops people using them
> outside of skbuff.c
> 
> Signed-off-by: Daniel Axtens <dja@...ens.net>

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@...il.com>

> 
> ---
> 
> v2: drop inline from functions.
> ---
>  include/linux/skbuff.h | 33 ---------------------------------
>  net/core/skbuff.c      | 37 +++++++++++++++++++++++++++++++++++--
>  2 files changed, 35 insertions(+), 35 deletions(-)
> 
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index a057dd1a75c7..ddf77cf4ff2d 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -3285,7 +3285,6 @@ int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
>  void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
>  int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
>  void skb_scrub_packet(struct sk_buff *skb, bool xnet);
> -unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
>  bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
>  bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
>  struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
> @@ -4104,38 +4103,6 @@ static inline bool skb_head_is_locked(const struct sk_buff *skb)
>  	return !skb->head_frag || skb_cloned(skb);
>  }
>  
> -/**
> - * skb_gso_network_seglen - Return length of individual segments of a gso packet
> - *
> - * @skb: GSO skb
> - *
> - * skb_gso_network_seglen is used to determine the real size of the
> - * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
> - *
> - * The MAC/L2 header is not accounted for.
> - */
> -static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
> -{
> -	unsigned int hdr_len = skb_transport_header(skb) -
> -			       skb_network_header(skb);
> -	return hdr_len + skb_gso_transport_seglen(skb);
> -}
> -
> -/**
> - * skb_gso_mac_seglen - Return length of individual segments of a gso packet
> - *
> - * @skb: GSO skb
> - *
> - * skb_gso_mac_seglen is used to determine the real size of the
> - * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4
> - * headers (TCP/UDP).
> - */
> -static inline unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
> -{
> -	unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
> -	return hdr_len + skb_gso_transport_seglen(skb);
> -}
> -
>  /* Local Checksum Offload.
>   * Compute outer checksum based on the assumption that the
>   * inner checksum will be offloaded later.
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index b63767008824..0bb0d8877954 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -4891,7 +4891,7 @@ EXPORT_SYMBOL_GPL(skb_scrub_packet);
>   *
>   * The MAC/L2 or network (IP, IPv6) headers are not accounted for.
>   */
> -unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
> +static unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
>  {
>  	const struct skb_shared_info *shinfo = skb_shinfo(skb);
>  	unsigned int thlen = 0;
> @@ -4913,7 +4913,40 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
>  	 */
>  	return thlen + shinfo->gso_size;
>  }
> -EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
> +
> +/**
> + * skb_gso_network_seglen - Return length of individual segments of a gso packet
> + *
> + * @skb: GSO skb
> + *
> + * skb_gso_network_seglen is used to determine the real size of the
> + * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
> + *
> + * The MAC/L2 header is not accounted for.
> + */
> +static unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
> +{
> +	unsigned int hdr_len = skb_transport_header(skb) -
> +			       skb_network_header(skb);
> +
> +	return hdr_len + skb_gso_transport_seglen(skb);
> +}
> +
> +/**
> + * skb_gso_mac_seglen - Return length of individual segments of a gso packet
> + *
> + * @skb: GSO skb
> + *
> + * skb_gso_mac_seglen is used to determine the real size of the
> + * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4
> + * headers (TCP/UDP).
> + */
> +static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
> +{
> +	unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
> +
> +	return hdr_len + skb_gso_transport_seglen(skb);
> +}
>  
>  /**
>   * skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS
> -- 
> 2.14.1
>