[PATCH v2 net 0/4] Do not use RT_TOS for IPv6 flowlabel

[PATCH v2 net 0/4] Do not use RT_TOS for IPv6 flowlabel

[Matthias May]

According to Guillaume Nault RT_TOS should never be used for IPv6.

Quote:
RT_TOS() is an old macro used to interprete IPv4 TOS as described in
the obsolete RFC 1349. It's conceptually wrong to use it even in IPv4
code, although, given the current state of the code, most of the
existing calls have no consequence.

But using RT_TOS() in IPv6 code is always a bug: IPv6 never had a "TOS"
field to be interpreted the RFC 1349 way. There's no historical
compatibility to worry about.

---
v1 -> v2:
 - Fix spacing of "Fixes" tag.
 - Add missing CCs

Matthias May (4):
  geneve: do not use RT_TOS for IPv6 flowlabel
  vxlan: do not use RT_TOS for IPv6 flowlabel
  mlx5: do not use RT_TOS for IPv6 flowlabel
  ipv6: do not use RT_TOS for IPv6 flowlabel

 drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 4 ++--
 drivers/net/geneve.c                                | 3 +--
 drivers/net/vxlan/vxlan_core.c                      | 2 +-
 net/ipv6/ip6_output.c                               | 3 +--
 4 files changed, 5 insertions(+), 7 deletions(-)

-- 
2.35.1

[PATCH v2 net 1/4] geneve: do not use RT_TOS for IPv6 flowlabel

[Matthias May]

According to Guillaume Nault RT_TOS should never be used for IPv6.

Fixes: 3a56f86f1be6a ("geneve: handle ipv6 priority like ipv4 tos")
Signed-off-by: Matthias May <matthias.may@westermo.com>
---
v1 -> v2:
 - Fix spacing of "Fixes" tag.
 - Add missing CCs
---
 drivers/net/geneve.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 4c380c06f178..e1a4480e6f17 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -877,8 +877,7 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
 		use_cache = false;
 	}
 
-	fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
-					   info->key.label);
+	fl6->flowlabel = ip6_make_flowinfo(prio, info->key.label);
 	dst_cache = (struct dst_cache *)&info->dst_cache;
 	if (use_cache) {
 		dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
-- 
2.35.1

Re: [PATCH v2 net 1/4] geneve: do not use RT_TOS for IPv6 flowlabel

[Guillaume Nault]

On Tue, Aug 02, 2022 at 02:09:32PM +0200, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.

While I obviously agree with this statement, I don't think it brings
much information to other people reading the commit message. Even
though the cover letter has more information, it won't be immediately
available to people reading the patch. Also the cover letter will be
lost if the patch gets picked up for the -stable trees.

Appart from that, I'm fine with the patch of course.

> Fixes: 3a56f86f1be6a ("geneve: handle ipv6 priority like ipv4 tos")
> Signed-off-by: Matthias May <matthias.may@westermo.com>
> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> ---
>  drivers/net/geneve.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
> index 4c380c06f178..e1a4480e6f17 100644
> --- a/drivers/net/geneve.c
> +++ b/drivers/net/geneve.c
> @@ -877,8 +877,7 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
>  		use_cache = false;
>  	}
>  
> -	fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
> -					   info->key.label);
> +	fl6->flowlabel = ip6_make_flowinfo(prio, info->key.label);
>  	dst_cache = (struct dst_cache *)&info->dst_cache;
>  	if (use_cache) {
>  		dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
> -- 
> 2.35.1
> 

Re: [PATCH v2 net 1/4] geneve: do not use RT_TOS for IPv6 flowlabel

[Guillaume Nault]

On Tue, Aug 02, 2022 at 02:09:32PM +0200, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.
> 
> Fixes: 3a56f86f1be6a ("geneve: handle ipv6 priority like ipv4 tos")

While I'm at it, the SHA1 is normally truncated to 12 charaters, not 13.

> Signed-off-by: Matthias May <matthias.may@westermo.com>
> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> ---
>  drivers/net/geneve.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
> index 4c380c06f178..e1a4480e6f17 100644
> --- a/drivers/net/geneve.c
> +++ b/drivers/net/geneve.c
> @@ -877,8 +877,7 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
>  		use_cache = false;
>  	}
>  
> -	fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
> -					   info->key.label);
> +	fl6->flowlabel = ip6_make_flowinfo(prio, info->key.label);
>  	dst_cache = (struct dst_cache *)&info->dst_cache;
>  	if (use_cache) {
>  		dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
> -- 
> 2.35.1
> 

Re: [PATCH v2 net 1/4] geneve: do not use RT_TOS for IPv6 flowlabel

[Matthias May]

[-- Attachment #1.1: Type: text/plain, Size: 514 bytes --]


On 03/08/2022 13:30, Guillaume Nault wrote:
> On Tue, Aug 02, 2022 at 02:09:32PM +0200, Matthias May wrote:
>> According to Guillaume Nault RT_TOS should never be used for IPv6.
>>
>> Fixes: 3a56f86f1be6a ("geneve: handle ipv6 priority like ipv4 tos")
> 
> While I'm at it, the SHA1 is normally truncated to 12 charaters, not 13.
> 

Hi Guillaume
Ups, missed to remove the additional character in this patch.
For some reason git blame shows the SHA1 with 13 characters, not sure why.

BR
Matthias

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Re: [PATCH v2 net 1/4] geneve: do not use RT_TOS for IPv6 flowlabel

[David Ahern]

On 8/2/22 6:09 AM, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.
> 
> Fixes: 3a56f86f1be6a ("geneve: handle ipv6 priority like ipv4 tos")
> Signed-off-by: Matthias May <matthias.may@westermo.com>
> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> ---
>  drivers/net/geneve.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>

[PATCH v2 net 2/4] vxlan: do not use RT_TOS for IPv6 flowlabel

[Matthias May]

According to Guillaume Nault RT_TOS should never be used for IPv6.

Fixes: 1400615d64cf ("vxlan: allow setting ipv6 traffic class")
Signed-off-by: Matthias May <matthias.may@westermo.com>
---
v1 -> v2:
 - Fix spacing of "Fixes" tag.
 - Add missing CCs
---
 drivers/net/vxlan/vxlan_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 265d4a0245e7..797585fbb004 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2320,7 +2320,7 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
 	fl6.flowi6_oif = oif;
 	fl6.daddr = *daddr;
 	fl6.saddr = *saddr;
-	fl6.flowlabel = ip6_make_flowinfo(RT_TOS(tos), label);
+	fl6.flowlabel = ip6_make_flowinfo(tos, label);
 	fl6.flowi6_mark = skb->mark;
 	fl6.flowi6_proto = IPPROTO_UDP;
 	fl6.fl6_dport = dport;
-- 
2.35.1

Re: [PATCH v2 net 2/4] vxlan: do not use RT_TOS for IPv6 flowlabel

[David Ahern]

On 8/2/22 6:09 AM, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.
> 
> Fixes: 1400615d64cf ("vxlan: allow setting ipv6 traffic class")
> Signed-off-by: Matthias May <matthias.may@westermo.com>
> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> ---
>  drivers/net/vxlan/vxlan_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>

[PATCH v2 net 3/4] mlx5: do not use RT_TOS for IPv6 flowlabel

[Matthias May]

According to Guillaume Nault RT_TOS should never be used for IPv6.

Fixes: ce99f6b97fcd ("net/mlx5e: Support SRIOV TC encapsulation offloads for IPv6 tunnels")
Signed-off-by: Matthias May <matthias.may@westermo.com>
---
v1 -> v2:
 - Fix spacing of "Fixes" tag.
 - Add missing CCs
---
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
index d87bbb0be7c8..e6f64d890fb3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
@@ -506,7 +506,7 @@ int mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv,
 	int err;
 
 	attr.ttl = tun_key->ttl;
-	attr.fl.fl6.flowlabel = ip6_make_flowinfo(RT_TOS(tun_key->tos), tun_key->label);
+	attr.fl.fl6.flowlabel = ip6_make_flowinfo(tun_key->tos, tun_key->label);
 	attr.fl.fl6.daddr = tun_key->u.ipv6.dst;
 	attr.fl.fl6.saddr = tun_key->u.ipv6.src;
 
@@ -620,7 +620,7 @@ int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv,
 
 	attr.ttl = tun_key->ttl;
 
-	attr.fl.fl6.flowlabel = ip6_make_flowinfo(RT_TOS(tun_key->tos), tun_key->label);
+	attr.fl.fl6.flowlabel = ip6_make_flowinfo(tun_key->tos, tun_key->label);
 	attr.fl.fl6.daddr = tun_key->u.ipv6.dst;
 	attr.fl.fl6.saddr = tun_key->u.ipv6.src;
 
-- 
2.35.1

[PATCH v2 net 4/4] ipv6: do not use RT_TOS for IPv6 flowlabel

[Matthias May]

According to Guillaume Nault RT_TOS should never be used for IPv6.

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Matthias May <matthias.may@westermo.com>
---
v1 -> v2:
 - Fix spacing of "Fixes" tag.
 - Add missing CCs
---
 net/ipv6/ip6_output.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 77e3f5970ce4..ec62f472aa1c 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1311,8 +1311,7 @@ struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
 	fl6.daddr = info->key.u.ipv6.dst;
 	fl6.saddr = info->key.u.ipv6.src;
 	prio = info->key.tos;
-	fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio),
-					  info->key.label);
+	fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label);
 
 	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
 					      NULL);
-- 
2.35.1

Re: [PATCH v2 net 4/4] ipv6: do not use RT_TOS for IPv6 flowlabel

[David Ahern]

On 8/2/22 6:09 AM, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.
> 
> Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
> Signed-off-by: Matthias May <matthias.may@westermo.com>
> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> ---
>  net/ipv6/ip6_output.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 


Reviewed-by: David Ahern <dsahern@kernel.org>

Re: [PATCH v2 net 0/4] Do not use RT_TOS for IPv6 flowlabel

[Guillaume Nault]

On Tue, Aug 02, 2022 at 02:09:31PM +0200, Matthias May wrote:
> According to Guillaume Nault RT_TOS should never be used for IPv6.
> 
> Quote:
> RT_TOS() is an old macro used to interprete IPv4 TOS as described in
> the obsolete RFC 1349. It's conceptually wrong to use it even in IPv4
> code, although, given the current state of the code, most of the
> existing calls have no consequence.
> 
> But using RT_TOS() in IPv6 code is always a bug: IPv6 never had a "TOS"
> field to be interpreted the RFC 1349 way. There's no historical
> compatibility to worry about.

Apart from the not so informative commit messages, I'm fine with this
series. Please keep my acked-by on all patches if you send a v3.

Thanks again for fixing this.

Acked-by: Guillaume Nault <gnault@redhat.com>

> ---
> v1 -> v2:
>  - Fix spacing of "Fixes" tag.
>  - Add missing CCs
> 
> Matthias May (4):
>   geneve: do not use RT_TOS for IPv6 flowlabel
>   vxlan: do not use RT_TOS for IPv6 flowlabel
>   mlx5: do not use RT_TOS for IPv6 flowlabel
>   ipv6: do not use RT_TOS for IPv6 flowlabel
> 
>  drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 4 ++--
>  drivers/net/geneve.c                                | 3 +--
>  drivers/net/vxlan/vxlan_core.c                      | 2 +-
>  net/ipv6/ip6_output.c                               | 3 +--
>  4 files changed, 5 insertions(+), 7 deletions(-)
> 
> -- 
> 2.35.1
>