From: Olivier MATZ <olivier.matz@6wind.com>
To: "Liu, Jijiang" <jijiang.liu@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 1/4] rte_mbuf:add packet types
Date: Fri, 21 Nov 2014 14:25:38 +0100 [thread overview]
Message-ID: <546F3D52.3070300@6wind.com> (raw)
In-Reply-To: <1ED644BD7E0A5F4091CF203DAFB8E4CC01D9D8D6@SHSMSX101.ccr.corp.intel.com>
Hello Jijiang,
On 11/21/2014 01:26 PM, Liu, Jijiang wrote:
>> I have one question about the packet_type: it is not clear to me what the
>> software can expect, for instance when RTE_PTYPE_IPv4_IPv4 is set. What does
>> that mean exactly? Which fields must be valid in the packet to have this type?
>> - L2 ethertype
>> - Presence of vlan?
>> - IP version
>> - IP checksum
>> - IP header length
>> - IP length (compared to packet len)
>> - anything about IP options?
> The RTE_PTYPE_IPv4_IPv4 means that packet format is MAC, IPV4, IPV4, PAY3. The following fields are valid,
> L2 ethertype
> No VLAN
> IPv4,
OK. But IPv4 is not a field, it's a header composed of several fields.
When a network stack receives a packet, it checks the validity of the
IPv4 fields. The offload flags helps the application to avoid doing
some checks, that's why it's important to know what the hardware
already verified when a flag is set.
Here is a example of what the application may check. Knowing the
meaning of the flag is having an answer to these questions. I probably
forgot some, but I think you get the point.
When RTE_PTYPE_IPv4 is set does it mean that IP.version is 4?
When RTE_PTYPE_IPv4 is set does it mean that IP.ihl is not smaller
than 5?
When RTE_PTYPE_IPv4 is set does it mean that IP.ihl is not higher
than 15?
When RTE_PTYPE_IPv4 is set does it mean that IP.checksum is
verified?
When RTE_PTYPE_IPv4 is set does it mean that IP.total_len is
not lower than 20?
When RTE_PTYPE_IPv4 is set does it mean that IP.total_len is
not higher than m_len(m) + 14?
When RTE_PTYPE_IPv4 is set does it mean that IP.total_len is
not lower than m_len(m) + 14? (there is a trap here)
When RTE_PTYPE_IPv4 is set does it mean that (IP.flags & 1) is 0?
When RTE_PTYPE_IPv4 is set does it mean that IP.offset is lower
than 65528?
When RTE_PTYPE_IPv4 is set, can the packet be a fragment?
When RTE_PTYPE_IPv4 is set does it mean that there is no options?
Any condition on source/dest address?
The same questions (but adapted to the protocol) could be asked for
any packet type, that was just an example.
>> - remove similar things in ol_flags to avoid having a redundant API.
>
> Yes, when all i40e/ixgbe/igb PMDs done, the related IP header offload should be removed.
> I just changed for i40e, there still are igb&ixgbe need to be changed in DPDK2.0, so we can't remove the IP ol_flags now.
How can an application deal with 2 different APIs ?
The application should work with any driver. It can have a i40e
interface and an ixgbe interface at the same time.
Regards,
Olivier
next prev parent reply other threads:[~2014-11-21 13:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-18 7:37 [dpdk-dev] [PATCH 0/4] Translate packet types for i40e Jijiang Liu
2014-11-18 7:37 ` [dpdk-dev] [PATCH 1/4] rte_mbuf:add packet types Jijiang Liu
2014-11-19 10:38 ` Olivier MATZ
2014-11-21 12:26 ` Liu, Jijiang
2014-11-21 13:25 ` Olivier MATZ [this message]
2014-11-18 7:37 ` [dpdk-dev] [PATCH 2/4] rte_mbuf:remove tunneling IP offload flags Jijiang Liu
2014-11-18 7:37 ` [dpdk-dev] [PATCH 3/4] i40e:translate i40e packet types Jijiang Liu
2014-11-18 7:37 ` [dpdk-dev] [PATCH 4/4] testpmd:application changes Jijiang Liu
2014-11-18 11:33 ` [dpdk-dev] [PATCH 0/4] Translate packet types for i40e Ananyev, Konstantin
2014-11-18 13:08 ` Bruce Richardson
2014-11-18 15:29 ` Ananyev, Konstantin
2014-11-19 3:52 ` Liu, Jijiang
2014-11-19 9:47 ` Ananyev, Konstantin
2014-11-18 14:12 ` Zhang, Helin
2014-11-18 15:26 ` Ananyev, Konstantin
2014-11-18 15:55 ` Ananyev, Konstantin
2014-11-19 0:29 ` Zhang, Helin
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