Re: [RFC PATCH net-next v4 2/4] net/sched: flower: Add PPPoE filter

Guillaume Nault
2022-07-08T19:23:10Z

On Fri, Jul 08, 2022 at 02:24:19PM +0200, Marcin Szycik wrote:
> From: Wojciech Drewek <wojciech.drewek@intel.com>
>
> Add support for PPPoE specific fields for tc-flower.
> Those fields can be provided only when protocol was set
> to ETH_P_PPP_SES. Defines, dump, load and set are being done here.
>
> Overwrite basic.n_proto only in case of PPP_IP and PPP_IPV6,

... and PPP_MPLS_UC/PPP_MPLS_MC in this new patch version.

> otherwise leave it as ETH_P_PPP_SES.
>
> Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
> ---
> v4:
> * support of MPLS inner fields
> * session_id stored in __be16
>
> include/uapi/linux/pkt_cls.h | 3 ++
> net/sched/cls_flower.c | 61 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 64 insertions(+)
>
> diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
> index 9a2ee1e39fad..c142c0f8ed8a 100644
> --- a/include/uapi/linux/pkt_cls.h
> +++ b/include/uapi/linux/pkt_cls.h
> @@ -589,6 +589,9 @@ enum {
>
> TCA_FLOWER_KEY_NUM_OF_VLANS, /* u8 */
>
> + TCA_FLOWER_KEY_PPPOE_SID, /* be16 */
> + TCA_FLOWER_KEY_PPP_PROTO, /* be16 */
> +
> __TCA_FLOWER_MAX,
> };
>
> diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
> index dcca70144dff..2a0ebad0e61c 100644
> --- a/net/sched/cls_flower.c
> +++ b/net/sched/cls_flower.c
> @@ -16,6 +16,7 @@
> #include <linux/in6.h>
> #include <linux/ip.h>
> #include <linux/mpls.h>
> +#include <linux/ppp_defs.h>
>
> #include <net/sch_generic.h>
> #include <net/pkt_cls.h>
> @@ -73,6 +74,7 @@ struct fl_flow_key {
> struct flow_dissector_key_ct ct;
> struct flow_dissector_key_hash hash;
> struct flow_dissector_key_num_of_vlans num_of_vlans;
> + struct flow_dissector_key_pppoe pppoe;
> } __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */
>
> struct fl_flow_mask_range {
> @@ -714,6 +716,8 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
> [TCA_FLOWER_KEY_HASH] = { .type = NLA_U32 },
> [TCA_FLOWER_KEY_HASH_MASK] = { .type = NLA_U32 },
> [TCA_FLOWER_KEY_NUM_OF_VLANS] = { .type = NLA_U8 },
> + [TCA_FLOWER_KEY_PPPOE_SID] = { .type = NLA_U16 },
> + [TCA_FLOWER_KEY_PPP_PROTO] = { .type = NLA_U16 },
>
> };
>
> @@ -1041,6 +1045,50 @@ static void fl_set_key_vlan(struct nlattr **tb,
> }
> }
>
> +static void fl_set_key_pppoe(struct nlattr **tb,
> + struct flow_dissector_key_pppoe *key_val,
> + struct flow_dissector_key_pppoe *key_mask,
> + struct fl_flow_key *key,
> + struct fl_flow_key *mask)
> +{
> + /* key_val::type must be set to ETH_P_PPP_SES
> + * because ETH_P_PPP_SES was stored in basic.n_proto
> + * which might get overwritten by ppp_proto
> + * or might be set to 0, the role of key_val::type
> + * is simmilar to vlan_key::tpid

Didn't you mean "vlan_tpid"?

> + */
> + key_val->type = htons(ETH_P_PPP_SES);
> + key_mask->type = cpu_to_be16(~0);
> +
> + if (tb[TCA_FLOWER_KEY_PPPOE_SID]) {
> + key_val->session_id =
> + nla_get_be16(tb[TCA_FLOWER_KEY_PPPOE_SID]);
> + key_mask->session_id = cpu_to_be16(~0);
> + }
> + if (tb[TCA_FLOWER_KEY_PPP_PROTO]) {
> + key_val->ppp_proto =
> + nla_get_be16(tb[TCA_FLOWER_KEY_PPP_PROTO]);
> + key_mask->ppp_proto = cpu_to_be16(~0);
> +
> + if (key_val->ppp_proto == htons(PPP_IP)) {
> + key->basic.n_proto = htons(ETH_P_IP);
> + mask->basic.n_proto = cpu_to_be16(~0);
> + } else if (key_val->ppp_proto == htons(PPP_IPV6)) {
> + key->basic.n_proto = htons(ETH_P_IPV6);
> + mask->basic.n_proto = cpu_to_be16(~0);
> + } else if (key_val->ppp_proto == htons(PPP_MPLS_UC)) {
> + key->basic.n_proto = htons(ETH_P_MPLS_UC);
> + mask->basic.n_proto = cpu_to_be16(~0);
> + } else if (key_val->ppp_proto == htons(PPP_MPLS_MC)) {
> + key->basic.n_proto = htons(ETH_P_MPLS_MC);
> + mask->basic.n_proto = cpu_to_be16(~0);
> + }
> + } else {
> + key->basic.n_proto = 0;
> + mask->basic.n_proto = cpu_to_be16(0);
> + }
> +}
> +
> static void fl_set_key_flag(u32 flower_key, u32 flower_mask,
> u32 *dissector_key, u32 *dissector_mask,
> u32 flower_flag_bit, u32 dissector_flag_bit)
> @@ -1651,6 +1699,9 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
> }
> }
>
> + if (key->basic.n_proto == htons(ETH_P_PPP_SES))
> + fl_set_key_pppoe(tb, &key->pppoe, &mask->pppoe, key, mask);
> +
> if (key->basic.n_proto == htons(ETH_P_IP) ||
> key->basic.n_proto == htons(ETH_P_IPV6)) {
> fl_set_key_val(tb, &key->basic.ip_proto, TCA_FLOWER_KEY_IP_PROTO,
> @@ -1923,6 +1974,8 @@ static void fl_init_dissector(struct flow_dissector *dissector,
> FLOW_DISSECTOR_KEY_HASH, hash);
> FL_KEY_SET_IF_MASKED(mask, keys, cnt,
> FLOW_DISSECTOR_KEY_NUM_OF_VLANS, num_of_vlans);
> + FL_KEY_SET_IF_MASKED(mask, keys, cnt,
> + FLOW_DISSECTOR_KEY_PPPOE, pppoe);
>
> skb_flow_dissector_init(dissector, keys, cnt);
> }
> @@ -3051,6 +3104,14 @@ static int fl_dump_key(struct sk_buff *skb, struct net *net,
> fl_dump_key_ip(skb, false, &key->ip, &mask->ip)))
> goto nla_put_failure;
>
> + if (mask->pppoe.session_id &&
> + nla_put_be16(skb, TCA_FLOWER_KEY_PPPOE_SID, key->pppoe.session_id))
> + goto nla_put_failure;
> +
> + if (mask->basic.n_proto && mask->pppoe.ppp_proto &&
> + nla_put_be16(skb, TCA_FLOWER_KEY_PPP_PROTO, key->pppoe.ppp_proto))
> + goto nla_put_failure;
> +
> if (key->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS &&
> (fl_dump_key_val(skb, &key->ipv4.src, TCA_FLOWER_KEY_IPV4_SRC,
> &mask->ipv4.src, TCA_FLOWER_KEY_IPV4_SRC_MASK,
> --
> 2.35.1
>