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Updating generic-table-dev branch with p4lang:p4runtime:main (#468)
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* Update Go dependencies (#438)

* Fixes #439 (#440)

Change CI  workflow to skip publishing if PR spawned by dependabot

* Adding dev branches to workflows (#443)

* Support for initial entries (#432)

* Define P4Runtime API support for tables with initial entries

* Add TODO asking whether the format for the contents of entries files
should be specified in the P4Runtime spec.

* Fix a couple of things found by linter and compiling protobuf

* Update autogenerated files

* Document that TableEntry const field must be false in write requests

* Add an appendix describing the contents of entries files generated by p4c

* Clarify some wording.

* Fix Madoko lint check

* Replace TODO with cross reference to new appendix on entries files
and clean up Madoko formatting in that appendix.

* Replace TODO with an optimistic footnote.

* Propose that TableEntry has new field const true for const entries
and also for const default_action

* Update auto-generated files

* Define has_initial_entries to be true for tables with `const entries`
Also fix a couple of spelling typos.

* Update auto-generated files

* Address several review comments

* Address some more review comments.

* Update auto-generated files again

* Slight change in definition of has_initial_entries flag
Propose that it is true if and only if the table property `entries` is
present, _and_ the list of entries is not empty.

* Update auto-generated files

* Add "added in 1.4.0" notes to the two new fields

* Clarify the description of the content of an entries file

* Fix a typo, and add is_const field to list of TableEntry fields

* Address review comment in new appendix

* Fix #434: Remove obsolete TODO section in README (#447)

* Fix #434: Remove obsolete TODO section in README
Update the link to the auto-generated versions of the P4Runtime
specification on the P4.org web site.

Update the section "P4 Language Version Applicability" to version
1.2.4 of the P4_16 language specification, but list 3 known exceptions
of features that have not been explicitly addressed yet.

* Add P4_16 v1.2.4 language spec features that may need addressing
in a future version of the P4Runtime API specification.

* Update discussion of entry priorities in constant tables (#457)

* Update discussion of entry priorities in constant tables

* Correct description of entry priority for constant tables

* Bump golang.org/x/net from 0.9.0 to 0.17.0 (#461)

Bumps [golang.org/x/net](https://github.com/golang/net) from 0.9.0 to 0.17.0.
- [Commits](golang/net@v0.9.0...v0.17.0)

---
updated-dependencies:
- dependency-name: golang.org/x/net
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Remove 4 P4 language spec compatibility issues from the list (#459)

* Remove 4 P4 language spec compatibility issues from the list
During 2023-Sep-08 P4.org API work group meeting, it was agreed that
there are no changes required to the P4Runtime API specification to be
compatible with these updates in the language spec.

* Add clarifying behavior of table with no `key` property back in
since there are potentially open issues around p4c implementation and
how it generates size field of tables in P4Info files that should be
considered before considering that issue resolved.

* Add metadata to multicast group entry (#446)

Same role as the metadata field for table entry

* Add proto_build_test rule that tests building the protos defined in the workspace. (#460)

* Update license kind to Apache2.0 instead of generic notice (#464)

* Bump google.golang.org/grpc from 1.56.1 to 1.56.3 (#465)

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.56.1 to 1.56.3.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.56.1...v1.56.3)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: Antonin Bas <[email protected]>
Co-authored-by: Chris Sommers <[email protected]>
Co-authored-by: Andy Fingerhut <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: verios-google <[email protected]>
Co-authored-by: anksaiki <[email protected]>
Co-authored-by: anksaiki <[email protected]>
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8 people authored Jan 26, 2024
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2 changes: 1 addition & 1 deletion .github/workflows/ci-build-proto.yml
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Expand Up @@ -40,7 +40,7 @@ jobs:
sudo mv $BAZEL /usr/local/bin/bazel
- name: Build proto/
run: cd proto && bazel build //...
run: cd proto && bazel build //... && bazel test //...

- name: Build bazel/example/
run: cd bazel/example/ && bazel build //...
186 changes: 167 additions & 19 deletions docs/v1/P4Runtime-Spec.mdk
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Expand Up @@ -230,8 +230,24 @@ format and available at
P4Runtime is designed to be implemented in conjunction with the P4~16~ language
version or later. P4~14~ programs should be translated into P4~16~ to be made
compatible with P4Runtime. This version of P4Runtime utilizes features which are
not in P4~16~ 1.0, but were introduced in P4~16~ 1.1.0 [@P4Revisions110]. For
this version of P4Runtime, we recommend using P4~16~ 1.2.1 [@P4Spec].
not in P4~16~ 1.0, but were introduced in P4~16~ 1.2.4 [@P4Revisions124]. For
this version of P4Runtime, we recommend using P4~16~ 1.2.4 [@P4Revisions124].

This version of the P4Runtime specification does not yet explicitly
address compatibility with the following P4~16~ language features
introduced in versions 1.2.2 or 1.2.4 of the language specification:

* Added support for generic structures [@P4Revisions122].
* Added support for additional enumeration types [@P4Revisions122].
* Added support for 0-width bitstrings and varbits [@P4Revisions122].
* Clarified restrictions for parameters with default values
[@P4Revisions124].
* Allow ranges to be specified by serializable enums
[@P4Revisions124].
* Added `list` type [@P4Revisions124].
* Clarified behavior of table with no `key` property, or if its list
of keys is empty [@P4Revisions124].


## In Scope

Expand Down Expand Up @@ -1524,6 +1540,12 @@ control plane. This message contains the following fields:
* `is_const_table`, a boolean flag indicating that the table is filled with
static entries and cannot be modified by the control plane at runtime.

* `has_initial_entries`, a boolean flag indicating that the table has
entries populated into it when the P4 program is loaded, which is
true for tables in the P4 source code with either the `entries` or
`const entries` properties, and there is at least one entry in the
list.

* `other_properties`, an `Any` Protobuf message [@ProtoAny] to embed
architecture-specific table properties [@P4TableProperties] which are not part
of the core P4 language or of the PSA architecture.
Expand Down Expand Up @@ -3010,6 +3032,9 @@ the `TableEntry` entity, which has the following fields:
implement idle-timeout support for the table, if applicable. See
[Idle-timeout](#sec-idle-timeout) section for more information.

* `is_const`, a boolean value that is `true` if and only if the entry
cannot be modified or deleted by the client.

The `priority` field must be set to a non-zero value if the match key includes a
ternary match (&ie; in the case of PSA if the P4Info entry for the table
indicates that one or more of its match fields has an `OPTIONAL`, `TERNARY` or
Expand Down Expand Up @@ -3043,6 +3068,10 @@ limitation. It is recommended that, for the sake of portability, P4Runtime
clients do not try to insert additional entries once the size indicated in
P4Info has been reached.

The `is_const` field must be `false` in any `INSERT`, `MODIFY`, or
`DELETE` write request of a table entry. If it is true, the server
must reject the operation and return an `INVALID_ARGUMENT` error.

### Match Format { #sec-match-format}

The bytes fields in the `FieldMatch` message follow the format described in
Expand Down Expand Up @@ -3270,10 +3299,16 @@ indirect tables --- tables with an ActionProfile or ActionSelector
`implementation` property --- to a constant `NoAction` action entry, with the
hope that it would simplify the implementation of the P4Runtime service.

### Constant Tables
### Constant Tables { #sec-constant-tables }

Constant tables are defined as tables whose match entries are immutable. They
are identified by the `is_const_table` flag in P4Info.
Constant tables are defined as tables whose match entries are
immutable. They are identified by the table property `const entries`
in the P4~16~ source code. In the P4Info, such tables have
`is_const_table` equal to true, and if the list of entries in the
source code has at least one entry in it, they also have
`has_initial_entries` flag equal to true. For tables declared with
the `entries` property, without `const` before `entries` see Section
[#sec-preinitialized-tables].

The only write updates which are allowed for constant tables are `MODIFY`
operations on direct resources, and the default action (assuming the default
Expand All @@ -3290,13 +3325,74 @@ The contents of const tables can be queried by the client through a
the following fields must be set by the server: `table_id`, `match`, `action`,
`is_default_action`, and `priority` (if required). This is in addition to any
direct resources that are being queried. Idle timeouts are not supported for
static entries. If the table requires a priority value for entries, the server
must populate the `priority` field appropriately, starting at 1 for the lowest
priority entry and incrementing the value by 1 for each successive entry. Note
that P4~16~ does not support assigning explicit priorities to static
entries. When a priority value is required (&eg; for tables including `RANGE`,
`TERNARY` or `OPTIONAL` matches), it is inferred based on the order in which
entries appear in the table declaration.
static entries.

When a priority value is required (&eg; for tables including `RANGE`,
`TERNARY` or `OPTIONAL` matches), it is inferred based on the order in
which entries appear in the table declaration. As of August 2023, the
open source `p4c` compiler always assigns entry priority values in a
constant table with `N` entries starting at `N` for the first entry
and decrementing the value by 1 for each successive entry. The P4~16~
language specification does not preclude the P4 developer from
explicitly specifying priorities for entries in constant tables, but
`p4c` does not yet support this.

### Preinitialized tables { #sec-preinitialized-tables }

Preinitialized tables are those defined with an `entries` table
property in the P4~16~ source code, with no `const` qualifier before
`entries`, and at least one entry in that list. In the P4Info, such
tables have `has_initial_entries` flag equal to true, but
`is_const_table` is false. For tables declared with `const entries`,
see Section [#sec-constant-tables].

Every P4 table falls into one of three categories:

* *Normal table*: Neither `entries` nor `const entries` are declared
in the source code, and thus `is_const_table` and
`has_initial_entries` will both be false. A corner case is that if
it has `entries = { }` with no `const` before `entries`, &ie; an
empty list of entries, that is also a normal table.
* *Constant table*: The table has `const entries` declared, and thus a
separate `entries` property is not permitted by the language. Such
a table will have `is_const_table` true. Such a table will have
`has_initial_entries` true if there is at least one entry in the
source code, or false if the list is empty.
* *Preinitialized table*: The table has `entries` declared, and thus a
separate `const entries` property is not permitted by the language.
It also has at least one entry in the list. Such a table will have
`is_const_table` false and `has_initial_entries` true.

A preinitialized table is allowed to have a mix of some entries marked
`const`, and other entries not marked `const`.

Entries not marked `const` may be modified or deleted, just as a
client may do for any entry in a normal table.

Entries marked `const` behave like entries in a constant table,
&ie; only `MODIFY` operations on direct resources are allowed.

Unlike a table with `is_const_table = true`, a client may insert
entries into a table with `has_initial_entries = true` and
`is_const_table = false`, subject to capacity constraints on the
number of entries supported by the target for the table.

The contents of preinitialized tables can be queried by the client
through a `ReadRequest`. The server fills in the same fields in the
response as it does for constant tables, as described in Section
[#sec-constant-tables], and with the same restrictions on table
features supported.

If the table requires a priority value for entries, the priorities of
the initial entries are determined according to the P4~16~ language
specification. After the P4 program is initially loaded, the entries
not marked `const` can be modified at run time just as table entries
in a normal table can.

The contents of all table entries within the `entries` table
properties in a P4 program can be written to a separate output file by
the open source `p4c` compiler. See Section [#sec-entries-files] for
details.

### Wildcard Reads { #sec-table-wildcard-reads}

Expand Down Expand Up @@ -4363,14 +4459,18 @@ semantics.
server must return an `INVALID_ARGUMENT` error. The egress port (`port` field)
must be an SDN port and must refer to a singleton port. No two replicas may
have identical values of *both* `port` and `instance`, or the server must
return `INVALID_ARGUMENT`.
* `MODIFY`: Modify the set of replicas for a given multicast group entry,
indexed by the given `multicast_group_id`. Same restrictions as `INSERT` apply
here.
return `INVALID_ARGUMENT`. The `metadata` field is an arbitrary `bytes` value
which is opaque to the target. There is no requirement of where this is
stored, but it must be returned by the server along with the rest of the entry
when the client performs a read on the entry.
* `MODIFY`: Modify the set of replicas and metadata for a given multicast group
entry, indexed by the given `multicast_group_id`. Same restrictions as
`INSERT` apply here.
* `DELETE`: Delete the multicast group indexed by the given
`multicast_group_id`. The replicas need not be provided for this
operation. Any packets with their `multicast_group` metadata in the data plane
set to the deleted `multicast_group_id` will be dropped.
`multicast_group_id`. The `replicas` and `metadata` fields need not be
provided for this operation. Any packets with their `multicast_group`
metadata in the data plane set to the deleted `multicast_group_id` will be
dropped.

When reading a multicast group, only `multicast_group_id` is considered. All
other fields in `MulticastGroupEntry` are ignored. To perform a *wildcard*
Expand Down Expand Up @@ -6343,6 +6443,7 @@ properties, but we may include on in future versions of the API.

### Changes in v1.4.0

* Add a `metadata` field to the `MulticastGroupEntry` message.
* Clarify that the limitation on supported types for `FieldMatch`, action
`Param`, and Packet IO metadata fields (no support for signed integers, with
type `int<W>`) apply to all minor revisions of P4Runtime v1, not just to
Expand Down Expand Up @@ -6598,4 +6699,51 @@ clients are aware that the server is using a larger maximum receive message
size. The gRPC server running the P4Runtime service must not set the maximum
receive message size to a value smaller than the default (4MB).

## P4Runtime Entries files { #sec-entries-files }

The open source P4 compiler `p4c` [@p4c] implements an option to
generate an "entries file", &ie; a file that contains all table
entries declared via the `entries` table property within the program.

An example P4~16~ program that can be used to demonstrate this
capability is `table-entries-ternary-bmv2.p4` [@p4cTestProgramForConstEntries]:

git clone https://github.com/p4lang/p4c
cd p4c/testdata/p4_16_samples
mkdir tmp
p4test --arch v1model \
--p4runtime-files tmp/p4info.txt \
--p4runtime-entries-files tmp/entries.txt \
table-entries-ternary-bmv2.p4

You can replace the `.txt` suffix of the file name `tmp/entries.txt`
in the example command above with `.json` or `.bin`. The `.bin`
format is a binary P4Runtime API protobuf message format. The `.txt`
format is the text encoding of the same Protobuf messages.

Target devices are *not* required to use this file. For example, if a
target has a P4 compiler back end that encodes all of the necessary
details from the P4 source program, including the `entries` of tables,
in a target-specific binary format, then that target might have no
reason to generate these entries files.

Some target devices might choose to generate entries files, and also
to require doing so in order to have a correct implementation. For
example, a target runtime implementation might take a target-specific
binary format for the compiled P4 program that does *not* contain any
data describing the `entries` of tables, plus the entries file
generated by `p4c`, and use the entries file to load the initial
entries of tables into the device.

The format of the entries file is a single `WriteRequest` message
containing one `Update` sub-message per entry in the P4 source program
defined via an `entries` table property. All `Update` sub-messages
have `type` equal to `INSERT`, and `entity` is a `TableEntry` message
containing the data for one table entry.

Note that if a P4Runtime client attempted to send a `WriteRequest` to
a P4Runtime server with the contents of the entries file, the server
must return an error for each entry that has `is_const` true, as
described in Section [#sec-table-entry].

[BIB]
13 changes: 2 additions & 11 deletions docs/v1/README.md
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Expand Up @@ -7,7 +7,8 @@ specification document.

The markup version uses Madoko (https://www.madoko.net) to produce
HTML and PDF versions of the documentation. Pre-built versions of the
documentation are available at **[TODO]**
documentation are available on the [P4.org specifications
page](https://p4.org/specs).


Files:
Expand Down Expand Up @@ -63,13 +64,3 @@ Note that to build the PDF you need a functional TeX version installed.
You need to install miktex [http://miktex.org/], madoko
[https://www.madoko.net/] and node.js [https://nodejs.org/en/]. To
build you can invoke the make.bat script.


# TODO
## Formating Fixups TODO

## Content TODO
Following are major content items which are missing or incomplete:
* Section 17. P4Runtime Versioning
* Section 18. Extending P4Runtime for non-PSA architectures
* Section 19. Lifetime of a session
20 changes: 20 additions & 0 deletions docs/v1/references.bib
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Expand Up @@ -65,6 +65,16 @@ @ONLINE { P4Revisions110
url = "https://p4.org/p4-spec/docs/P4-16-v1.2.1.html#sec-summary-of-changes-made-in-version-110"
}

@ONLINE { P4Revisions122,
title = "Summary of changes made in $P4_{16}$ version 1.2.2",
url = "https://p4.org/p4-spec/docs/P4-16-v1.2.4.html#sec-summary-of-changes-made-in-version-122-released-may-17-2021"
}

@ONLINE { P4Revisions124,
title = "Summary of changes made in $P4_{16}$ version 1.2.4",
url = "https://p4.org/p4-spec/docs/P4-16-v1.2.4.html#sec-summary-of-changes-made-in-version-124"
}

@ONLINE { P4Spec,
title = "$P4_{16}$ 1.2.1 specification",
url = "https://p4.org/p4-spec/docs/P4-16-v1.2.1.html"
Expand Down Expand Up @@ -210,3 +220,13 @@ @ONLINE { ArenaAllocation
title = "C++ Arena Allocation Guide",
url = "https://developers.google.com/protocol-buffers/docs/reference/arenas"
}

@ONLINE { p4c,
title = "P4_16 reference compiler",
url = "https://github.com/p4lang/p4c"
}

@ONLINE { p4cTestProgramForConstEntries,
title = "P4_16 reference compiler test program table-entries-ternary-bmv2.p4",
url = "https://github.com/p4lang/p4c/blob/main/testdata/p4_16_samples/table-entries-ternary-bmv2.p4"
}
8 changes: 4 additions & 4 deletions go.mod
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Expand Up @@ -4,13 +4,13 @@ go 1.20

require (
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1
google.golang.org/grpc v1.56.1
google.golang.org/grpc v1.56.3
google.golang.org/protobuf v1.31.0
)

require (
github.com/golang/protobuf v1.5.3 // indirect
golang.org/x/net v0.9.0 // indirect
golang.org/x/sys v0.7.0 // indirect
golang.org/x/text v0.9.0 // indirect
golang.org/x/net v0.17.0 // indirect
golang.org/x/sys v0.13.0 // indirect
golang.org/x/text v0.13.0 // indirect
)
16 changes: 8 additions & 8 deletions go.sum
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Expand Up @@ -3,17 +3,17 @@ github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg
github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
golang.org/x/net v0.9.0 h1:aWJ/m6xSmxWBx+V0XRHTlrYrPG56jKsLdTFmsSsCzOM=
golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/text v0.13.0 h1:ablQoSUd0tRdKxZewP80B+BaqeKJuVhuRxj/dkrun3k=
golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 h1:KpwkzHKEF7B9Zxg18WzOa7djJ+Ha5DzthMyZYQfEn2A=
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1/go.mod h1:nKE/iIaLqn2bQwXBg8f1g2Ylh6r5MN5CmZvuzZCgsCU=
google.golang.org/grpc v1.56.1 h1:z0dNfjIl0VpaZ9iSVjA6daGatAYwPGstTjt5vkRMFkQ=
google.golang.org/grpc v1.56.1/go.mod h1:I9bI3vqKfayGqPUAwGdOSu7kt6oIJLixfffKrpXqQ9s=
google.golang.org/grpc v1.56.3 h1:8I4C0Yq1EjstUzUJzpcRVbuYA2mODtEmpWiQoN/b2nc=
google.golang.org/grpc v1.56.3/go.mod h1:I9bI3vqKfayGqPUAwGdOSu7kt6oIJLixfffKrpXqQ9s=
google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
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