[PATCH AUTOSEL 5.7 103/274] net: mscc: ocelot: deal with problematic MAC_ETYPE VCAP IS2 rules

Sasha Levin
2020-06-09T01:00:08Z

From: Vladimir Oltean <vladimir.oltean@nxp.com>

[ Upstream commit 89f9ffd3eb670bad1260bc579f5e13b8f2d5b3e0 ]

By default, the VCAP IS2 will produce a single match for each frame, on
the most specific classification.

Example: a ping packet (ICMP over IPv4 over Ethernet) sent from an IP
address of 10.0.0.1 and a MAC address of 96:18:82:00:04:01 will match
this rule:

tc filter add dev swp0 ingress protocol ipv4 \
flower skip_sw src_ip 10.0.0.1 action drop

but not this one:

tc filter add dev swp0 ingress \
flower skip_sw src_mac 96:18:82:00:04:01 action drop

Currently the driver does not really warn the user in any way about
this, and the behavior is rather strange anyway.

The current patch is a workaround to force matches on MAC_ETYPE keys
(DMAC and SMAC) for all packets irrespective of higher layer protocol.
The setting is made at the port level.

Of course this breaks all other non-src_mac and non-dst_mac matches, so
rule exclusivity checks have been added to the driver, in order to never
have rules of both types on any ingress port.

The bits that discard higher-level protocol information are set only
once a MAC_ETYPE rule is added to a filter block, and only for the ports
that are bound to that filter block. Then all further non-MAC_ETYPE
rules added to that filter block should be denied by the ports bound to
it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mscc/ocelot_ace.c | 103 +++++++++++++++++++++-
drivers/net/ethernet/mscc/ocelot_ace.h | 5 +-
drivers/net/ethernet/mscc/ocelot_flower.c | 2 +-
3 files changed, 106 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_ace.c b/drivers/net/ethernet/mscc/ocelot_ace.c
index 3bd286044480..8a2f7d13ef6d 100644
--- a/drivers/net/ethernet/mscc/ocelot_ace.c
+++ b/drivers/net/ethernet/mscc/ocelot_ace.c
@@ -706,13 +706,114 @@ ocelot_ace_rule_get_rule_index(struct ocelot_acl_block *block, int index)
return NULL;
}

+/* If @on=false, then SNAP, ARP, IP and OAM frames will not match on keys based
+ * on destination and source MAC addresses, but only on higher-level protocol
+ * information. The only frame types to match on keys containing MAC addresses
+ * in this case are non-SNAP, non-ARP, non-IP and non-OAM frames.
+ *
+ * If @on=true, then the above frame types (SNAP, ARP, IP and OAM) will match
+ * on MAC_ETYPE keys such as destination and source MAC on this ingress port.
+ * However the setting has the side effect of making these frames not matching
+ * on any _other_ keys than MAC_ETYPE ones.
+ */
+static void ocelot_match_all_as_mac_etype(struct ocelot *ocelot, int port,
+ bool on)
+{
+ u32 val = 0;
+
+ if (on)
+ val = ANA_PORT_VCAP_S2_CFG_S2_SNAP_DIS(3) |
+ ANA_PORT_VCAP_S2_CFG_S2_ARP_DIS(3) |
+ ANA_PORT_VCAP_S2_CFG_S2_IP_TCPUDP_DIS(3) |
+ ANA_PORT_VCAP_S2_CFG_S2_IP_OTHER_DIS(3) |
+ ANA_PORT_VCAP_S2_CFG_S2_OAM_DIS(3);
+
+ ocelot_rmw_gix(ocelot, val,
+ ANA_PORT_VCAP_S2_CFG_S2_SNAP_DIS_M |
+ ANA_PORT_VCAP_S2_CFG_S2_ARP_DIS_M |
+ ANA_PORT_VCAP_S2_CFG_S2_IP_TCPUDP_DIS_M |
+ ANA_PORT_VCAP_S2_CFG_S2_IP_OTHER_DIS_M |
+ ANA_PORT_VCAP_S2_CFG_S2_OAM_DIS_M,
+ ANA_PORT_VCAP_S2_CFG, port);
+}
+
+static bool ocelot_ace_is_problematic_mac_etype(struct ocelot_ace_rule *ace)
+{
+ if (ace->type != OCELOT_ACE_TYPE_ETYPE)
+ return false;
+ if (ether_addr_to_u64(ace->frame.etype.dmac.value) &
+ ether_addr_to_u64(ace->frame.etype.dmac.mask))
+ return true;
+ if (ether_addr_to_u64(ace->frame.etype.smac.value) &
+ ether_addr_to_u64(ace->frame.etype.smac.mask))
+ return true;
+ return false;
+}
+
+static bool ocelot_ace_is_problematic_non_mac_etype(struct ocelot_ace_rule *ace)
+{
+ if (ace->type == OCELOT_ACE_TYPE_SNAP)
+ return true;
+ if (ace->type == OCELOT_ACE_TYPE_ARP)
+ return true;
+ if (ace->type == OCELOT_ACE_TYPE_IPV4)
+ return true;
+ if (ace->type == OCELOT_ACE_TYPE_IPV6)
+ return true;
+ return false;
+}
+
+static bool ocelot_exclusive_mac_etype_ace_rules(struct ocelot *ocelot,
+ struct ocelot_ace_rule *ace)
+{
+ struct ocelot_acl_block *block = &ocelot->acl_block;
+ struct ocelot_ace_rule *tmp;
+ unsigned long port;
+ int i;
+
+ if (ocelot_ace_is_problematic_mac_etype(ace)) {
+ /* Search for any non-MAC_ETYPE rules on the port */
+ for (i = 0; i < block->count; i++) {
+ tmp = ocelot_ace_rule_get_rule_index(block, i);
+ if (tmp->ingress_port_mask & ace->ingress_port_mask &&
+ ocelot_ace_is_problematic_non_mac_etype(tmp))
+ return false;
+ }
+
+ for_each_set_bit(port, &ace->ingress_port_mask,
+ ocelot->num_phys_ports)
+ ocelot_match_all_as_mac_etype(ocelot, port, true);
+ } else if (ocelot_ace_is_problematic_non_mac_etype(ace)) {
+ /* Search for any MAC_ETYPE rules on the port */
+ for (i = 0; i < block->count; i++) {
+ tmp = ocelot_ace_rule_get_rule_index(block, i);
+ if (tmp->ingress_port_mask & ace->ingress_port_mask &&
+ ocelot_ace_is_problematic_mac_etype(tmp))
+ return false;
+ }
+
+ for_each_set_bit(port, &ace->ingress_port_mask,
+ ocelot->num_phys_ports)
+ ocelot_match_all_as_mac_etype(ocelot, port, false);
+ }
+
+ return true;
+}
+
int ocelot_ace_rule_offload_add(struct ocelot *ocelot,
- struct ocelot_ace_rule *rule)
+ struct ocelot_ace_rule *rule,
+ struct netlink_ext_ack *extack)
{
struct ocelot_acl_block *block = &ocelot->acl_block;
struct ocelot_ace_rule *ace;
int i, index;

+ if (!ocelot_exclusive_mac_etype_ace_rules(ocelot, rule)) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Cannot mix MAC_ETYPE with non-MAC_ETYPE rules");
+ return -EBUSY;
+ }
+
/* Add rule to the linked list */
ocelot_ace_rule_add(ocelot, block, rule);

diff --git a/drivers/net/ethernet/mscc/ocelot_ace.h b/drivers/net/ethernet/mscc/ocelot_ace.h
index 29d22c566786..099e177f2617 100644
--- a/drivers/net/ethernet/mscc/ocelot_ace.h
+++ b/drivers/net/ethernet/mscc/ocelot_ace.h
@@ -194,7 +194,7 @@ struct ocelot_ace_rule {

enum ocelot_ace_action action;
struct ocelot_ace_stats stats;
- u16 ingress_port_mask;
+ unsigned long ingress_port_mask;

enum ocelot_vcap_bit dmac_mc;
enum ocelot_vcap_bit dmac_bc;
@@ -215,7 +215,8 @@ struct ocelot_ace_rule {
};

int ocelot_ace_rule_offload_add(struct ocelot *ocelot,
- struct ocelot_ace_rule *rule);
+ struct ocelot_ace_rule *rule,
+ struct netlink_ext_ack *extack);
int ocelot_ace_rule_offload_del(struct ocelot *ocelot,
struct ocelot_ace_rule *rule);
int ocelot_ace_rule_stats_update(struct ocelot *ocelot,
diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c
index 341923311fec..954cb67eeaa2 100644
--- a/drivers/net/ethernet/mscc/ocelot_flower.c
+++ b/drivers/net/ethernet/mscc/ocelot_flower.c
@@ -205,7 +205,7 @@ int ocelot_cls_flower_replace(struct ocelot *ocelot, int port,
return ret;
}

- return ocelot_ace_rule_offload_add(ocelot, ace);
+ return ocelot_ace_rule_offload_add(ocelot, ace, f->common.extack);
}
EXPORT_SYMBOL_GPL(ocelot_cls_flower_replace);

--
2.25.1