From: Simon Horman <horms@kernel.org>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org,
pabeni@redhat.com, edumazet@google.com, laforge@osmocom.org,
pespin@sysmocom.de, osmith@sysmocom.de
Subject: Re: [PATCH net-next,v3 02/12] gtp: properly parse extension headers
Date: Thu, 9 May 2024 13:14:41 +0100 [thread overview]
Message-ID: <20240509121441.GL1736038@kernel.org> (raw)
In-Reply-To: <20240506235251.3968262-3-pablo@netfilter.org>
On Tue, May 07, 2024 at 01:52:41AM +0200, Pablo Neira Ayuso wrote:
> Currently GTP packets are dropped if the next extension field is set to
> non-zero value, but this are valid GTP packets.
>
> TS 29.281 provides a longer header format, which is defined as struct
> gtp1_header_long. Such long header format is used if any of the S, PN, E
> flags is set.
>
> This long header is 4 bytes longer than struct gtp1_header, plus
> variable length (optional) extension headers. The next extension header
> field is zero is no extension header is provided.
>
> The extension header is composed of a length field which includes total
> number of 4 byte words including the extension header itself (1 byte),
> payload (variable length) and next type (1 byte). The extension header
> size and its payload is aligned to 4 bytes.
>
> A GTP packet might come with a chain extensions headers, which makes it
> slightly cumbersome to parse because the extension next header field
> comes at the end of the extension header, and there is a need to check
> if this field becomes zero to stop the extension header parser.
>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2024-05-09 12:14 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 23:52 [PATCH net-next,v3 00/12] gtp updates for net-next (v3) Pablo Neira Ayuso
2024-05-06 23:52 ` [PATCH net-next,v3 01/12] gtp: remove useless initialization Pablo Neira Ayuso
2024-05-09 10:19 ` Simon Horman
2024-05-10 13:10 ` patchwork-bot+netdevbpf
2024-05-06 23:52 ` [PATCH net-next,v3 02/12] gtp: properly parse extension headers Pablo Neira Ayuso
2024-05-09 12:14 ` Simon Horman [this message]
2024-05-06 23:52 ` [PATCH net-next,v3 03/12] gtp: prepare for IPv6 support Pablo Neira Ayuso
2024-05-09 12:15 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 04/12] gtp: add " Pablo Neira Ayuso
2024-05-09 12:15 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 05/12] gtp: use IPv6 address /64 prefix for UE/MS Pablo Neira Ayuso
2024-05-09 12:15 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 06/12] gtp: pass up link local traffic to userspace socket Pablo Neira Ayuso
2024-05-09 12:16 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 07/12] gtp: move debugging to skbuff build helper function Pablo Neira Ayuso
2024-05-09 12:16 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 08/12] gtp: remove IPv4 and IPv6 header from context object Pablo Neira Ayuso
2024-05-09 12:17 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 09/12] gtp: add helper function to build GTP packets from an IPv4 packet Pablo Neira Ayuso
2024-05-09 12:17 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 10/12] gtp: add helper function to build GTP packets from an IPv6 packet Pablo Neira Ayuso
2024-05-09 12:17 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 11/12] gtp: support for IPv4-in-IPv6-GTP and IPv6-in-IPv4-GTP Pablo Neira Ayuso
2024-05-09 12:18 ` Simon Horman
2024-05-06 23:52 ` [PATCH net-next,v3 12/12] gtp: identify tunnel via GTP device + GTP version + TEID + family Pablo Neira Ayuso
2024-05-09 12:19 ` Simon Horman
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