Dmitry Eremin-Solenikov(lumag) replied on github web page:
include/odp/api/spec/packet.h
line 74
@@ -1140,6 +1179,82 @@ int odp_packet_move_data(odp_packet_t pkt, uint32_t
dst_offset,
*/
/**
+ * Packet parse parameters
+ */
+typedef struct odp_packet_parse_param_t {
+ /** Protocol header at parse starting point. Valid values for this
+ * field are: ODP_PROTO_ETH, ODP_PROTO_IPV4, ODP_PROTO_IPV6. */
+ odp_proto_t proto;
+
+ /** Continue parsing until this layer. Must be the same or higher
+ * layer than the layer of 'proto'. */
+ odp_proto_layer_t layer;
+
+ /** Flags to control payload data checks up to the selected parse
+ * layer. Checksum checking status can be queried for each packet with
+ * odp_packet_l3_chksum_status() and odp_packet_l4_chksum_status().
+ */
+ union {
+ struct {
+ /** Check IPv4 header checksum */
+ uint32_t ipv4_chksum : 1;
+
+ /** Check UDP checksum */
+ uint32_t udp_chksum : 1;
+
+ /** Check TCP checksum */
+ uint32_t tcp_chksum : 1;
Comment:
What about just `l3_chksum`, and `l4_chksum`?
> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
> Now that we have a `param` struct we should have an
> `odp_packet_parse_param_init()` API as well for completeness.
>> Dmitry Eremin-Solenikov(lumag) wrote:
>> @Bill-Fischofer-Linaro Because it is a parsing error, if lower layer
>> provides us IP version that does not correspond to the in-packet version. We
>> should detect that, rather than silently parsing this header.
>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>> I'm not sure why an API named `odp_packet_parse()` needs help here. It's
>>> purpose, after all, is to parse packets and determining IPv4 vs IPv6 is
>>> part of that activity. Moreover, the only way an application can inspect
>>> the IP header is to access it via other ODP API calls, so I don't see how
>>> asking the application to do this is any better than having the
>>> `odp_packet_parse()` implementation do this itself. What's the purpose of
>>> having a parse API in that case since clearly the application could parse
>>> the entire packet "by hand" as well.
>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>> Failure needs to be defined in a more precise way (and maybe for a single
>>>> packet case). I assume that it means internal ODP error, rather than just
>>>> packet with wrong headers. What happens in multi-packet case if failure
>>>> occurs in the middle of parsing?
>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>> @psavol Also for multi-packet parsing, we can change `proto` to be an
>>>>> array, allowing applications to easily intermix IPv4 and IPv6 packets.
>>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>>> @psavol yes. I just wanted to focus on cases, when passing packet with
>>>>>> wrong protocol is an error. E.g. IPv6 packet inside IPsec packet with NH
>>>>>> = 4. So it is not a question of selecting proper L3 parser, but rather a
>>>>>> question of nailing down error/malicious packets.
>>>>>>> Petri Savolainen(psavol) wrote:
>>>>>>> It's there to enable application to call parsing in parts - e.g. first
>>>>>>> up to IP and then continue from L4. But since IP and transport
>>>>>>> protocols are tied together with pseudo headers, it's cleaner to remove
>>>>>>> L4 as a starting point.
>>>>>>>> Petri Savolainen(psavol) wrote:
>>>>>>>> First bits of an IP header marks the version. So, it would be trivial
>>>>>>>> for both app and implementation to read the version from the data.
>>>>>>>> Common IP define is easier for application when a burst of packets may
>>>>>>>> contain both v4 and v6 mixed. Application does not need to sort
>>>>>>>> packets into two arrays (one for v4 and other for v6) but just pass
>>>>>>>> the entire array for parsing.
>>>>>>>>
>>>>>>>> There are three ways to define the enumeration: IP, IPv4+IPv6,
>>>>>>>> IP+IPv4+IPv6. I'm OK with any of those. IPv4+IPv6 would be a bit more
>>>>>>>> robust since version information comes from two sources.
>>>>>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>>>>>> I felt easier to reparse both L3 and L4 headers in IPsec case,
>>>>>>>>> especially since transport mode ESP can en/decrypt some of L3 headers
>>>>>>>>> in IPv6 case.
>>>>>>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>>>>>>> @Bill-Fischofer-Linaro In IPsec case Next Header field will contain
>>>>>>>>>> 4 for IPv4 and 41 for IPv6.
>>>>>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>>>>>> That might be overly complicated since until a decrypted tunnel
>>>>>>>>>>> mode IPsec packet is parsed you don't know whether it's IPv4 or
>>>>>>>>>>> IPv6. It's parsing that makes that determination.
>>>>>>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>>>>>>> @lumag IPsec operating in transport mode is, I'd imagine, the main
>>>>>>>>>>>> use case here.
>>>>>>>>>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>>>>>>>>>> What is the usecase for parsing a packet starting from L4 header?
>>>>>>>>>>>>> Also there are several (lots) of other L4 protocols. Do we want
>>>>>>>>>>>>> to support them all here?
>>>>>>>>>>>>>> Dmitry Eremin-Solenikov(lumag) wrote:
>>>>>>>>>>>>>> Maybe it would be better to split this into separate IPv4 and
>>>>>>>>>>>>>> IPv6 packets. It would be an error to pass IPv6 packet with
>>>>>>>>>>>>>> ethtype (or IP tunnel type) being set to IPv4.
>>>>>>>>>>>>>>> Petri Savolainen(psavol) wrote:
>>>>>>>>>>>>>>> A vector of packets is CPU vector instructions friendly.
>>>>>>>>>>>>>>>> Petri Savolainen(psavol) wrote:
>>>>>>>>>>>>>>>> The use case is mentioned in log message: parse after
>>>>>>>>>>>>>>>> decrypt/IP reassembly. Application has recreated an inner
>>>>>>>>>>>>>>>> packet and needs to parse it before continue. This is
>>>>>>>>>>>>>>>> inherently SW parse which may be accelerated with CPU vector
>>>>>>>>>>>>>>>> instructions, etc.
>>>>>>>>>>>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>>>>>>>>>>>> What's the use case for a multi() form of this API? Might VPP
>>>>>>>>>>>>>>>>> use it? Perhaps Sachin can comment?
>>>>>>>>>>>>>>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>>>>>>>>>>>>>>> We had considered an `odp_packet_parse()` function some time
>>>>>>>>>>>>>>>>>> back but it was rejected as something that would not fit
>>>>>>>>>>>>>>>>>> well with hardware parsers. What's changed?
https://github.com/Linaro/odp/pull/273#discussion_r149687036
updated_at 2017-11-08 14:41:14
