On 03/07/2019 15:48, Nikolay Aleksandrov wrote:
> On 03/07/2019 15:40, Pablo Neira Ayuso wrote:
>> Use br_vlan_enabled() and br_vlan_get_pvid() helpers as Nikolay
>> suggests.
>>
>> Rename NFT_META_BRI_PVID to NFT_META_BRI_IIFPVID before this patch hits
>> the 5.3 release cycle, to leave room for matching for the output bridge
>> port in the future.
>>
>> Reported-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
>> Fixes: da4f10a4265b ("netfilter: nft_meta: add NFT_META_BRI_PVID support")
>> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
>> ---
>> include/uapi/linux/netfilter/nf_tables.h | 4 ++--
>> net/netfilter/nft_meta.c | 17 ++++++++++-------
>> 2 files changed, 12 insertions(+), 9 deletions(-)
>>
>
> Ah actually I might've hurried too much with the suggestion, we don't have a helper to
> check through a port if vlan filtering has been enabled. The helper assumes that
> the device is a bridge. So below you'll have to use p->br->dev with br_vlan_enabled().
> And in fact the proper way would be to get the "upper" device via netdev_master_upper_dev_get()
> and then to use that in order to avoid direct dereferencing.
>
Sorry for the multiple replies, I just noticed this is running from fast-path so you'll
have to use the _rcu variant and check for null since they are unlinked before the port
flag is removed in del_nbp() (bridge/bf_if.c).
>> diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
>> index 8859535031e2..8a1bd0b1ec8c 100644
>> --- a/include/uapi/linux/netfilter/nf_tables.h
>> +++ b/include/uapi/linux/netfilter/nf_tables.h
>> @@ -795,7 +795,7 @@ enum nft_exthdr_attributes {
>> * @NFT_META_SECPATH: boolean, secpath_exists (!!skb->sp)
>> * @NFT_META_IIFKIND: packet input interface kind name (dev->rtnl_link_ops->kind)
>> * @NFT_META_OIFKIND: packet output interface kind name (dev->rtnl_link_ops->kind)
>> - * @NFT_META_BRI_PVID: packet input bridge port pvid
>> + * @NFT_META_BRI_IIFPVID: packet input bridge port pvid
>> */
>> enum nft_meta_keys {
>> NFT_META_LEN,
>> @@ -826,7 +826,7 @@ enum nft_meta_keys {
>> NFT_META_SECPATH,
>> NFT_META_IIFKIND,
>> NFT_META_OIFKIND,
>> - NFT_META_BRI_PVID,
>> + NFT_META_BRI_IIFPVID,
>> };
>>
>> /**
>> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
>> index 4f8116de70f8..b8d8adc0852e 100644
>> --- a/net/netfilter/nft_meta.c
>> +++ b/net/netfilter/nft_meta.c
>> @@ -240,14 +240,17 @@ void nft_meta_get_eval(const struct nft_expr *expr,
>> goto err;
>> strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
>> return;
>> - case NFT_META_BRI_PVID:
>> + case NFT_META_BRI_IIFPVID: {
>> + u16 p_pvid;
>> +
>> if (in == NULL || (p = br_port_get_rtnl_rcu(in)) == NULL)
>> goto err;
>> - if (br_opt_get(p->br, BROPT_VLAN_ENABLED)) {
>> - nft_reg_store16(dest, br_get_pvid(nbp_vlan_group_rcu(p)));
>> - return;
>> - }
>> - goto err;
>> + if (!br_vlan_enabled(in))
>> + goto err;
>> + br_vlan_get_pvid(in, &p_pvid);
>> + nft_reg_store16(dest, p_pvid);
>> + return;
>> + }
>> #endif
>> case NFT_META_IIFKIND:
>> if (in == NULL || in->rtnl_link_ops == NULL)
>> @@ -375,7 +378,7 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
>> return -EOPNOTSUPP;
>> len = IFNAMSIZ;
>> break;
>> - case NFT_META_BRI_PVID:
>> + case NFT_META_BRI_IIFPVID:
>> if (ctx->family != NFPROTO_BRIDGE)
>> return -EOPNOTSUPP;
>> len = sizeof(u16);
>>
>
