Bill Fischofer(Bill-Fischofer-Linaro) 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:
+1 since other checksum APIs refer to L3 and L4 rather than specific protocols.
> Dmitry Eremin-Solenikov(lumag) wrote:
> 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_r149697464
updated_at 2017-11-08 15:14:08
