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

Marcin Szycik
2022-07-08T12:25:02Z

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,
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
+ */
+ 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