[v4] net: introduce IPv4 ihl and version fields

Message ID 20211004121323.6677-1-getelson@nvidia.com (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series [v4] net: introduce IPv4 ihl and version fields |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/github-robot: build success github build: passed
ci/iol-aarch64-compile-testing success Testing PASS
ci/iol-x86_64-unit-testing fail Testing issues
ci/iol-x86_64-compile-testing fail Testing issues
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS

Commit Message

Etelson, Gregory Oct. 4, 2021, 12:13 p.m. UTC
RTE IPv4 header definition combines the `version' and `ihl'  fields
into a single structure member.
This patch introduces dedicated structure members for both `version'
and `ihl' IPv4 fields. Separated header fields definitions allow to
create simplified code to match on the IHL value in a flow rule.
The original `version_ihl' structure member is kept for backward
compatibility.

Signed-off-by: Gregory Etelson <getelson@nvidia.com>

Depends-on: f7383e7c7ec1 ("net: announce changes in IPv4 header access")

Acked-by: Olivier Matz <olivier.matz@6wind.com>

---
v2: Add dependency.
v3: Add comments.
v4: Update release notes.
---
 app/test/test_flow_classify.c          |  8 ++++----
 doc/guides/rel_notes/release_21_11.rst |  3 +++
 lib/net/rte_ip.h                       | 16 +++++++++++++++-
 3 files changed, 22 insertions(+), 5 deletions(-)
  

Comments

Stephen Hemminger Oct. 4, 2021, 3:59 p.m. UTC | #1
On Mon, 4 Oct 2021 15:13:22 +0300
Gregory Etelson <getelson@nvidia.com> wrote:

> diff --git a/app/test/test_flow_classify.c b/app/test/test_flow_classify.c
> index 951606f248..4f64be5357 100644
> --- a/app/test/test_flow_classify.c
> +++ b/app/test/test_flow_classify.c
> @@ -95,7 +95,7 @@ static struct rte_acl_field_def ipv4_defs[NUM_FIELDS_IPV4] = {
>   *  dst mask 255.255.255.00 / udp src is 32 dst is 33 / end"
>   */
>  static struct rte_flow_item_ipv4 ipv4_udp_spec_1 = {
> -	{ 0, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
> +	{ { .version_ihl = 0}, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
>  	  RTE_IPV4(2, 2, 2, 3), RTE_IPV4(2, 2, 2, 7)}
>  };

This ends up being an API change which was not announced.
  
Olivier Matz Oct. 4, 2021, 4:48 p.m. UTC | #2
On Mon, Oct 04, 2021 at 08:59:34AM -0700, Stephen Hemminger wrote:
> On Mon, 4 Oct 2021 15:13:22 +0300
> Gregory Etelson <getelson@nvidia.com> wrote:
> 
> > diff --git a/app/test/test_flow_classify.c b/app/test/test_flow_classify.c
> > index 951606f248..4f64be5357 100644
> > --- a/app/test/test_flow_classify.c
> > +++ b/app/test/test_flow_classify.c
> > @@ -95,7 +95,7 @@ static struct rte_acl_field_def ipv4_defs[NUM_FIELDS_IPV4] = {
> >   *  dst mask 255.255.255.00 / udp src is 32 dst is 33 / end"
> >   */
> >  static struct rte_flow_item_ipv4 ipv4_udp_spec_1 = {
> > -	{ 0, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
> > +	{ { .version_ihl = 0}, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
> >  	  RTE_IPV4(2, 2, 2, 3), RTE_IPV4(2, 2, 2, 7)}
> >  };
> 
> This ends up being an API change which was not announced.

It was announced (commit f7383e7c7ec1). But that's a good point:
- the removal of the deprecation is missing in the patch
- the message notice also talks about union for fragment_offset
  
Etelson, Gregory Oct. 12, 2021, 12:36 p.m. UTC | #3
Hello,

..snip..

> It was announced (commit f7383e7c7ec1). But
> that's a good point:
> - the removal of the deprecation is missing in the
> patch

I removed deprecation in v5

> - the message notice also talks about union for
> fragment_offset

A union for IPv4 fragmentation fields cannot be implemented.
IPv4 header encodes fragment information into 16 bits field.
3 bits hold flags and remaining 13 bits are for fragment offset.
13 bits bit-field cannot be defined both for big and little endian
systems.
  

Patch

diff --git a/app/test/test_flow_classify.c b/app/test/test_flow_classify.c
index 951606f248..4f64be5357 100644
--- a/app/test/test_flow_classify.c
+++ b/app/test/test_flow_classify.c
@@ -95,7 +95,7 @@  static struct rte_acl_field_def ipv4_defs[NUM_FIELDS_IPV4] = {
  *  dst mask 255.255.255.00 / udp src is 32 dst is 33 / end"
  */
 static struct rte_flow_item_ipv4 ipv4_udp_spec_1 = {
-	{ 0, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
+	{ { .version_ihl = 0}, 0, 0, 0, 0, 0, IPPROTO_UDP, 0,
 	  RTE_IPV4(2, 2, 2, 3), RTE_IPV4(2, 2, 2, 7)}
 };
 static const struct rte_flow_item_ipv4 ipv4_mask_24 = {
@@ -131,7 +131,7 @@  static struct rte_flow_item  end_item = { RTE_FLOW_ITEM_TYPE_END,
  *  dst mask 255.255.255.00 / tcp src is 16 dst is 17 / end"
  */
 static struct rte_flow_item_ipv4 ipv4_tcp_spec_1 = {
-	{ 0, 0, 0, 0, 0, 0, IPPROTO_TCP, 0,
+	{ { .version_ihl = 0}, 0, 0, 0, 0, 0, IPPROTO_TCP, 0,
 	  RTE_IPV4(1, 2, 3, 4), RTE_IPV4(5, 6, 7, 8)}
 };
 
@@ -150,8 +150,8 @@  static struct rte_flow_item  tcp_item_1 = { RTE_FLOW_ITEM_TYPE_TCP,
  *  dst mask 255.255.255.00 / sctp src is 16 dst is 17/ end"
  */
 static struct rte_flow_item_ipv4 ipv4_sctp_spec_1 = {
-	{ 0, 0, 0, 0, 0, 0, IPPROTO_SCTP, 0, RTE_IPV4(11, 12, 13, 14),
-	RTE_IPV4(15, 16, 17, 18)}
+	{ { .version_ihl = 0}, 0, 0, 0, 0, 0, IPPROTO_SCTP, 0,
+	RTE_IPV4(11, 12, 13, 14), RTE_IPV4(15, 16, 17, 18)}
 };
 
 static struct rte_flow_item_sctp sctp_spec_1 = {
diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index 73e377a007..deab44a92a 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -170,6 +170,9 @@  API Changes
   the crypto/security operation. This field will be used to communicate
   events such as soft expiry with IPsec in lookaside mode.
 
+* net: Add ``version`` and ``ihl`` bit-fields to ``struct rte_ipv4_hdr``.
+  Existing ``version_ihl`` field was kept for backward compatibility.
+
 
 ABI Changes
 -----------
diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h
index 05948b69b7..89a68d9433 100644
--- a/lib/net/rte_ip.h
+++ b/lib/net/rte_ip.h
@@ -38,7 +38,21 @@  extern "C" {
  * IPv4 Header
  */
 struct rte_ipv4_hdr {
-	uint8_t  version_ihl;		/**< version and header length */
+	__extension__
+	union {
+		uint8_t version_ihl;    /**< version and header length */
+		struct {
+#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
+			uint8_t ihl:4;     /**< header length */
+			uint8_t version:4; /**< version */
+#elif RTE_BYTE_ORDER == RTE_BIG_ENDIAN
+			uint8_t version:4; /**< version */
+			uint8_t ihl:4;     /**< header length */
+#else
+#error "setup endian definition"
+#endif
+		};
+	};
 	uint8_t  type_of_service;	/**< type of service */
 	rte_be16_t total_length;	/**< length of packet */
 	rte_be16_t packet_id;		/**< packet ID */