ethtool: add tunnel info interface

Add an interface to report offloaded UDP ports via ethtool netlink.

Now that core takes care of tracking which UDP tunnel ports the NICs
are aware of we can quite easily export this information out to
user space.

The responsibility of writing the netlink dumps is split between
ethtool code and udp_tunnel_nic.c - since udp_tunnel module may
not always be loaded, yet we should always report the capabilities
of the NIC.

$ ethtool --show-tunnels eth0
Tunnel information for eth0:
  UDP port table 0:
    Size: 4
    Types: vxlan
    No entries
  UDP port table 1:
    Size: 4
    Types: geneve, vxlan-gpe
    Entries (1):
        port 1230, vxlan-gpe

v4:
 - back to v2, build fix is now directly in udp_tunnel.h
v3:
 - don't compile ETHTOOL_MSG_TUNNEL_INFO_GET in if CONFIG_INET
   not set.
v2:
 - fix string set count,
 - reorder enums in the uAPI,
 - fix type of ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES to bitset
   in docs and comments.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Documentation/networking/ethtool-netlink.rst

@@ -1230,6 +1230,39 @@ used to report the amplitude of the reflection for a given pair.
  | | | ``ETHTOOL_A_CABLE_AMPLITUDE_mV``        | s16    | Reflection amplitude |
  +-+-+-----------------------------------------+--------+----------------------+
 
+TUNNEL_INFO
+===========
+
+Gets information about the tunnel state NIC is aware of.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_TUNNEL_INFO_HEADER``       nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_TUNNEL_INFO_HEADER``            | nested | reply header        |
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_TUNNEL_INFO_UDP_PORTS``         | nested | all UDP port tables |
+ +-+-------------------------------------------+--------+---------------------+
+ | | ``ETHTOOL_A_TUNNEL_UDP_TABLE``            | nested | one UDP port table  |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE``     | u32    | max size of the     |
+ | | |                                         |        | table               |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES``    | bitset | tunnel types which  |
+ | | |                                         |        | table can hold      |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY``    | nested | offloaded UDP port  |
+ +-+-+-+---------------------------------------+--------+---------------------+
+ | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT``   | be16   | UDP port            |
+ +-+-+-+---------------------------------------+--------+---------------------+
+ | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE``   | u32    | tunnel type         |
+ +-+-+-+---------------------------------------+--------+---------------------+
+
 Request translation
 ===================
 

include/net/udp_tunnel.h

@@ -255,6 +255,10 @@ struct udp_tunnel_nic_ops {
 	void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
 	void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
 	void (*reset_ntf)(struct net_device *dev);
+
+	size_t (*dump_size)(struct net_device *dev, unsigned int table);
+	int (*dump_write)(struct net_device *dev, unsigned int table,
+			  struct sk_buff *skb);
 };
 
 #ifdef CONFIG_INET
@@ -318,4 +322,21 @@ static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
 	if (udp_tunnel_nic_ops)
 		udp_tunnel_nic_ops->reset_ntf(dev);
 }
+
+static inline size_t
+udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
+{
+	if (!udp_tunnel_nic_ops)
+		return 0;
+	return udp_tunnel_nic_ops->dump_size(dev, table);
+}
+
+static inline int
+udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
+			  struct sk_buff *skb)
+{
+	if (!udp_tunnel_nic_ops)
+		return 0;
+	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
+}
 #endif

include/uapi/linux/ethtool.h

@@ -669,6 +669,7 @@ enum ethtool_link_ext_substate_cable_issue {
  * @ETH_SS_SOF_TIMESTAMPING: SOF_TIMESTAMPING_* flags
  * @ETH_SS_TS_TX_TYPES: timestamping Tx types
  * @ETH_SS_TS_RX_FILTERS: timestamping Rx filters
+ * @ETH_SS_UDP_TUNNEL_TYPES: UDP tunnel types
  */
 enum ethtool_stringset {
 	ETH_SS_TEST		= 0,
@@ -686,6 +687,7 @@ enum ethtool_stringset {
 	ETH_SS_SOF_TIMESTAMPING,
 	ETH_SS_TS_TX_TYPES,
 	ETH_SS_TS_RX_FILTERS,
+	ETH_SS_UDP_TUNNEL_TYPES,
 
 	/* add new constants above here */
 	ETH_SS_COUNT

include/uapi/linux/ethtool_netlink.h

@@ -41,6 +41,7 @@ enum {
 	ETHTOOL_MSG_TSINFO_GET,
 	ETHTOOL_MSG_CABLE_TEST_ACT,
 	ETHTOOL_MSG_CABLE_TEST_TDR_ACT,
+	ETHTOOL_MSG_TUNNEL_INFO_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -556,6 +557,60 @@ enum {
 	ETHTOOL_A_CABLE_TEST_TDR_NTF_MAX = __ETHTOOL_A_CABLE_TEST_TDR_NTF_CNT - 1
 };
 
+/* TUNNEL INFO */
+
+enum {
+	ETHTOOL_UDP_TUNNEL_TYPE_VXLAN,
+	ETHTOOL_UDP_TUNNEL_TYPE_GENEVE,
+	ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE,
+
+	__ETHTOOL_UDP_TUNNEL_TYPE_CNT
+};
+
+enum {
+	ETHTOOL_A_TUNNEL_UDP_ENTRY_UNSPEC,
+
+	ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,		/* be16 */
+	ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE,		/* u32 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TUNNEL_UDP_ENTRY_CNT,
+	ETHTOOL_A_TUNNEL_UDP_ENTRY_MAX = (__ETHTOOL_A_TUNNEL_UDP_ENTRY_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_TUNNEL_UDP_TABLE_UNSPEC,
+
+	ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE,		/* u32 */
+	ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES,		/* bitset */
+	ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY,		/* nest - _UDP_ENTRY_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TUNNEL_UDP_TABLE_CNT,
+	ETHTOOL_A_TUNNEL_UDP_TABLE_MAX = (__ETHTOOL_A_TUNNEL_UDP_TABLE_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_TUNNEL_UDP_UNSPEC,
+
+	ETHTOOL_A_TUNNEL_UDP_TABLE,			/* nest - _UDP_TABLE_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TUNNEL_UDP_CNT,
+	ETHTOOL_A_TUNNEL_UDP_MAX = (__ETHTOOL_A_TUNNEL_UDP_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_TUNNEL_INFO_UNSPEC,
+	ETHTOOL_A_TUNNEL_INFO_HEADER,			/* nest - _A_HEADER_* */
+
+	ETHTOOL_A_TUNNEL_INFO_UDP_PORTS,		/* nest - _UDP_TABLE */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TUNNEL_INFO_CNT,
+	ETHTOOL_A_TUNNEL_INFO_MAX = (__ETHTOOL_A_TUNNEL_INFO_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1

net/ethtool/Makefile

@@ -6,4 +6,5 @@ obj-$(CONFIG_ETHTOOL_NETLINK)	+= ethtool_nl.o
 
 ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
-		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o
+		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
+		   tunnels.o

net/ethtool/common.c

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
+#include <linux/ethtool_netlink.h>
 #include <linux/net_tstamp.h>
 #include <linux/phy.h>
 #include <linux/rtnetlink.h>
@@ -272,6 +273,14 @@ const char ts_rx_filter_names[][ETH_GSTRING_LEN] = {
 };
 static_assert(ARRAY_SIZE(ts_rx_filter_names) == __HWTSTAMP_FILTER_CNT);
 
+const char udp_tunnel_type_names[][ETH_GSTRING_LEN] = {
+	[ETHTOOL_UDP_TUNNEL_TYPE_VXLAN]		= "vxlan",
+	[ETHTOOL_UDP_TUNNEL_TYPE_GENEVE]	= "geneve",
+	[ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE]	= "vxlan-gpe",
+};
+static_assert(ARRAY_SIZE(udp_tunnel_type_names) ==
+	      __ETHTOOL_UDP_TUNNEL_TYPE_CNT);
+
 /* return false if legacy contained non-0 deprecated fields
  * maxtxpkt/maxrxpkt. rest of ksettings always updated
  */

net/ethtool/common.h

@@ -28,6 +28,7 @@ extern const char wol_mode_names[][ETH_GSTRING_LEN];
 extern const char sof_timestamping_names[][ETH_GSTRING_LEN];
 extern const char ts_tx_type_names[][ETH_GSTRING_LEN];
 extern const char ts_rx_filter_names[][ETH_GSTRING_LEN];
+extern const char udp_tunnel_type_names[][ETH_GSTRING_LEN];
 
 int __ethtool_get_link(struct net_device *dev);
 

net/ethtool/netlink.c

@@ -181,6 +181,12 @@ struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
 	return NULL;
 }
 
+void *ethnl_dump_put(struct sk_buff *skb, struct netlink_callback *cb, u8 cmd)
+{
+	return genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			   &ethtool_genl_family, 0, cmd);
+}
+
 void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
 {
 	return genlmsg_put(skb, 0, ++ethnl_bcast_seq, &ethtool_genl_family, 0,
@@ -849,6 +855,12 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_act_cable_test_tdr,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_TUNNEL_INFO_GET,
+		.doit	= ethnl_tunnel_info_doit,
+		.start	= ethnl_tunnel_info_start,
+		.dumpit	= ethnl_tunnel_info_dumpit,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {

net/ethtool/netlink.h

@@ -19,6 +19,7 @@ int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
 				 u16 hdr_attrtype, struct genl_info *info,
 				 void **ehdrp);
+void *ethnl_dump_put(struct sk_buff *skb, struct netlink_callback *cb, u8 cmd);
 void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd);
 int ethnl_multicast(struct sk_buff *skb, struct net_device *dev);
 
@@ -361,5 +362,8 @@ int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_eee(struct sk_buff *skb, struct genl_info *info);
 int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
 int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info);
+int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info);
+int ethnl_tunnel_info_start(struct netlink_callback *cb);
+int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 
 #endif /* _NET_ETHTOOL_NETLINK_H */

net/ethtool/strset.c

@@ -75,6 +75,11 @@ static const struct strset_info info_template[] = {
 		.count		= __HWTSTAMP_FILTER_CNT,
 		.strings	= ts_rx_filter_names,
 	},
+	[ETH_SS_UDP_TUNNEL_TYPES] = {
+		.per_dev	= false,
+		.count		= __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
+		.strings	= udp_tunnel_type_names,
+	},
 };
 
 struct strset_req_info {