On Thu, Oct 03, 2019 at 02:58:00PM -0700, Tom Herbert wrote:
> From: Tom Herbert <t...@quantonium.net>
>
> Create a generic TLV parser. This will be used with various
> extension headers that carry options including Destination,
> Hop-by-Hop, Segment Routing TLVs, and other cases of simple
> stateless parsing.
>
> Signed-off-by: Tom Herbert <t...@herbertland.com>
> ---
> include/net/ipeh.h | 25 ++++++++
> net/ipv6/exthdrs.c | 159
> +++++++++++-----------------------------------
> net/ipv6/exthdrs_common.c | 114 +++++++++++++++++++++++++++++++++
> 3 files changed, 177 insertions(+), 121 deletions(-)
>
> diff --git a/include/net/ipeh.h b/include/net/ipeh.h
> index 3b24831..c1aa7b6 100644
> --- a/include/net/ipeh.h
> +++ b/include/net/ipeh.h
> @@ -31,4 +31,29 @@ struct ipv6_txoptions *ipeh_renew_options(struct sock *sk,
> struct ipv6_txoptions *ipeh_fixup_options(struct ipv6_txoptions *opt_space,
> struct ipv6_txoptions *opt);
>
> +/* Generic extension header TLV parser */
> +
> +enum ipeh_parse_errors {
> + IPEH_PARSE_ERR_PAD1, /* Excessive PAD1 */
> + IPEH_PARSE_ERR_PADN, /* Excessive PADN */
> + IPEH_PARSE_ERR_PADNZ, /* Non-zero padding data */
> + IPEH_PARSE_ERR_EH_TOOBIG, /* Length of EH exceeds limit */
> + IPEH_PARSE_ERR_OPT_TOOBIG, /* Option size exceeds limit */
> + IPEH_PARSE_ERR_OPT_TOOMANY, /* Option count exceeds limit */
> + IPEH_PARSE_ERR_OPT_UNK_DISALW, /* Unknown option disallowed */
> + IPEH_PARSE_ERR_OPT_UNK, /* Unknown option */
> +};
> +
> +/* The generic TLV parser assumes that the type value of PAD1 is 0, and PADN
> + * is 1. This is true for Destination, Hop-by-Hop and current definition
> + * of Segment Routing TLVs.
> + */
> +#define IPEH_TLV_PAD1 0
> +#define IPEH_TLV_PADN 1
> +
> +bool ipeh_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb,
> + int max_count, int off, int len,
> + bool (*parse_error)(struct sk_buff *skb,
> + int off, enum ipeh_parse_errors error));
> +
> #endif /* _NET_IPEH_H */
Hi Tom,
Unless I misread things, which is entirely possible, it seems
as well as moving code around this patch changes behaviour under
some error conditions via the parse_error callback and
the ipv6_parse_error() implementation of it below.
I think such a change is worth of at lest calling out in the changelog
and perhaps braking out into a separate patch.
...
