Petri Savolainen(psavol) replied on github web page:
include/odp/api/spec/packet.h
line 83
@@ -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;
+
+ } check;
+
+ /** All check bits. This can be used to set/clear all flags. */
+ uint32_t all_check;
+ };
+
+} odp_packet_parse_param_t;
+
Comment:
Param init on fast path is a bit overkill. However, application could call it
once and store the result. So, it could avoid extra function call for every
packet. So, I'll add it.
> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
> `return i;` if we adopt the RC == number of successful packets parsed
> convention.
>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>> For consistency with other `odp_xxx_multi()` APIs, the RC should indicate
>> the number of input packets that were successfully processed.
>>> muvarov wrote
>>> it looks like 2 enums are not needed here. odp_proto_layet_t layer_start;
>>> and odp_proto_layet_t layer_end; and one enum for layers.
>>>> muvarov wrote
>>>> maybe return number of correctly parsed packets? And say that parsing
>>>> always starts from be beginning of array.
>>>>> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
>>>>> +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_r149897971
updated_at 2017-11-09 09:00:28
