[PATCH net-next v2 03/15] ethtool: provide netdev features with FEATURES_GET request

From: Michal Kubecek
Date: Thu Mar 12 2020 - 16:07:55 EST


Implement FEATURES_GET request to get network device features. These are
traditionally available via ETHTOOL_GFEATURES ioctl request.

v2:
- style cleanup suggested by Jakub Kicinski

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 51 ++++++--
include/uapi/linux/ethtool_netlink.h | 17 +++
net/ethtool/Makefile | 2 +-
net/ethtool/common.h | 2 +
net/ethtool/features.c | 131 +++++++++++++++++++
net/ethtool/ioctl.c | 2 -
net/ethtool/netlink.c | 8 ++
net/ethtool/netlink.h | 1 +
8 files changed, 202 insertions(+), 12 deletions(-)
create mode 100644 net/ethtool/features.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index f1f868479ceb..5713abf98534 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -189,6 +189,7 @@ Userspace to kernel:
``ETHTOOL_MSG_DEBUG_SET`` set debugging settings
``ETHTOOL_MSG_WOL_GET`` get wake-on-lan settings
``ETHTOOL_MSG_WOL_SET`` set wake-on-lan settings
+ ``ETHTOOL_MSG_FEATURES_GET`` get device features
===================================== ================================

Kernel to userspace:
@@ -204,6 +205,7 @@ Kernel to userspace:
``ETHTOOL_MSG_DEBUG_NTF`` debugging settings notification
``ETHTOOL_MSG_WOL_GET_REPLY`` wake-on-lan settings
``ETHTOOL_MSG_WOL_NTF`` wake-on-lan settings notification
+ ``ETHTOOL_MSG_FEATURES_GET_REPLY`` device features
===================================== =================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -521,6 +523,37 @@ Request contents:
``WAKE_MAGICSECURE`` mode.


+FEATURES_GET
+============
+
+Gets netdev features like ``ETHTOOL_GFEATURES`` ioctl request.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_FEATURES_HEADER`` nested request header
+ ==================================== ====== ==========================
+
+Kernel response contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_FEATURES_HEADER`` nested reply header
+ ``ETHTOOL_A_FEATURES_HW`` bitset dev->hw_features
+ ``ETHTOOL_A_FEATURES_WANTED`` bitset dev->wanted_features
+ ``ETHTOOL_A_FEATURES_ACTIVE`` bitset dev->features
+ ``ETHTOOL_A_FEATURES_NOCHANGE`` bitset NETIF_F_NEVER_CHANGE
+ ==================================== ====== ==========================
+
+Bitmaps in kernel response have the same meaning as bitmaps used in ioctl
+interference but attribute names are different (they are based on
+corresponding members of struct net_device). Legacy "flags" are not provided,
+if userspace needs them (most likely only ethtool for backward compatibility),
+it can calculate their values from related feature bits itself.
+ETHA_FEATURES_HW uses mask consisting of all features recognized by kernel (to
+provide all names when using verbose bitmap format), the other three use no
+mask (simple bit lists).
+
+
Request translation
===================

@@ -551,30 +584,30 @@ have their netlink replacement yet.
``ETHTOOL_SRINGPARAM`` n/a
``ETHTOOL_GPAUSEPARAM`` n/a
``ETHTOOL_SPAUSEPARAM`` n/a
- ``ETHTOOL_GRXCSUM`` n/a
+ ``ETHTOOL_GRXCSUM`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SRXCSUM`` n/a
- ``ETHTOOL_GTXCSUM`` n/a
+ ``ETHTOOL_GTXCSUM`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_STXCSUM`` n/a
- ``ETHTOOL_GSG`` n/a
+ ``ETHTOOL_GSG`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SSG`` n/a
``ETHTOOL_TEST`` n/a
``ETHTOOL_GSTRINGS`` ``ETHTOOL_MSG_STRSET_GET``
``ETHTOOL_PHYS_ID`` n/a
``ETHTOOL_GSTATS`` n/a
- ``ETHTOOL_GTSO`` n/a
+ ``ETHTOOL_GTSO`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_STSO`` n/a
``ETHTOOL_GPERMADDR`` rtnetlink ``RTM_GETLINK``
- ``ETHTOOL_GUFO`` n/a
+ ``ETHTOOL_GUFO`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SUFO`` n/a
- ``ETHTOOL_GGSO`` n/a
+ ``ETHTOOL_GGSO`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SGSO`` n/a
- ``ETHTOOL_GFLAGS`` n/a
+ ``ETHTOOL_GFLAGS`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SFLAGS`` n/a
``ETHTOOL_GPFLAGS`` n/a
``ETHTOOL_SPFLAGS`` n/a
``ETHTOOL_GRXFH`` n/a
``ETHTOOL_SRXFH`` n/a
- ``ETHTOOL_GGRO`` n/a
+ ``ETHTOOL_GGRO`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SGRO`` n/a
``ETHTOOL_GRXRINGS`` n/a
``ETHTOOL_GRXCLSRLCNT`` n/a
@@ -589,7 +622,7 @@ have their netlink replacement yet.
``ETHTOOL_GSSET_INFO`` ``ETHTOOL_MSG_STRSET_GET``
``ETHTOOL_GRXFHINDIR`` n/a
``ETHTOOL_SRXFHINDIR`` n/a
- ``ETHTOOL_GFEATURES`` n/a
+ ``ETHTOOL_GFEATURES`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SFEATURES`` n/a
``ETHTOOL_GCHANNELS`` n/a
``ETHTOOL_SCHANNELS`` n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 7e0b460f872c..d0cc7a0334c8 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -24,6 +24,7 @@ enum {
ETHTOOL_MSG_DEBUG_SET,
ETHTOOL_MSG_WOL_GET,
ETHTOOL_MSG_WOL_SET,
+ ETHTOOL_MSG_FEATURES_GET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
@@ -43,6 +44,7 @@ enum {
ETHTOOL_MSG_DEBUG_NTF,
ETHTOOL_MSG_WOL_GET_REPLY,
ETHTOOL_MSG_WOL_NTF,
+ ETHTOOL_MSG_FEATURES_GET_REPLY,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
@@ -228,6 +230,21 @@ enum {
ETHTOOL_A_WOL_MAX = __ETHTOOL_A_WOL_CNT - 1
};

+/* FEATURES */
+
+enum {
+ ETHTOOL_A_FEATURES_UNSPEC,
+ ETHTOOL_A_FEATURES_HEADER, /* nest - _A_HEADER_* */
+ ETHTOOL_A_FEATURES_HW, /* bitset */
+ ETHTOOL_A_FEATURES_WANTED, /* bitset */
+ ETHTOOL_A_FEATURES_ACTIVE, /* bitset */
+ ETHTOOL_A_FEATURES_NOCHANGE, /* bitset */
+
+ /* add new constants above here */
+ __ETHTOOL_A_FEATURES_CNT,
+ ETHTOOL_A_FEATURES_MAX = __ETHTOOL_A_FEATURES_CNT - 1
+};
+
/* generic netlink info */
#define ETHTOOL_GENL_NAME "ethtool"
#define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 424545a4aaec..5be8c9ab26d1 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -5,4 +5,4 @@ obj-y += ioctl.o common.o
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
+ linkstate.o debug.o wol.o features.o
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 40ba74e0b9bb..7dc1163800a7 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -6,6 +6,8 @@
#include <linux/netdevice.h>
#include <linux/ethtool.h>

+#define ETHTOOL_DEV_FEATURE_WORDS DIV_ROUND_UP(NETDEV_FEATURE_COUNT, 32)
+
/* compose link mode index from speed, type and duplex */
#define ETHTOOL_LINK_MODE(speed, type, duplex) \
ETHTOOL_LINK_MODE_ ## speed ## base ## type ## _ ## duplex ## _BIT
diff --git a/net/ethtool/features.c b/net/ethtool/features.c
new file mode 100644
index 000000000000..a0cc2b969053
--- /dev/null
+++ b/net/ethtool/features.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+#include "bitset.h"
+
+struct features_req_info {
+ struct ethnl_req_info base;
+};
+
+struct features_reply_data {
+ struct ethnl_reply_data base;
+ u32 hw[ETHTOOL_DEV_FEATURE_WORDS];
+ u32 wanted[ETHTOOL_DEV_FEATURE_WORDS];
+ u32 active[ETHTOOL_DEV_FEATURE_WORDS];
+ u32 nochange[ETHTOOL_DEV_FEATURE_WORDS];
+ u32 all[ETHTOOL_DEV_FEATURE_WORDS];
+};
+
+#define FEATURES_REPDATA(__reply_base) \
+ container_of(__reply_base, struct features_reply_data, base)
+
+static const struct nla_policy
+features_get_policy[ETHTOOL_A_FEATURES_MAX + 1] = {
+ [ETHTOOL_A_FEATURES_UNSPEC] = { .type = NLA_REJECT },
+ [ETHTOOL_A_FEATURES_HEADER] = { .type = NLA_NESTED },
+ [ETHTOOL_A_FEATURES_HW] = { .type = NLA_REJECT },
+ [ETHTOOL_A_FEATURES_WANTED] = { .type = NLA_REJECT },
+ [ETHTOOL_A_FEATURES_ACTIVE] = { .type = NLA_REJECT },
+ [ETHTOOL_A_FEATURES_NOCHANGE] = { .type = NLA_REJECT },
+};
+
+static void ethnl_features_to_bitmap32(u32 *dest, netdev_features_t src)
+{
+ unsigned int i;
+
+ for (i = 0; i < ETHTOOL_DEV_FEATURE_WORDS; i++)
+ dest[i] = src >> (32 * i);
+}
+
+static int features_prepare_data(const struct ethnl_req_info *req_base,
+ struct ethnl_reply_data *reply_base,
+ struct genl_info *info)
+{
+ struct features_reply_data *data = FEATURES_REPDATA(reply_base);
+ struct net_device *dev = reply_base->dev;
+ netdev_features_t all_features;
+
+ ethnl_features_to_bitmap32(data->hw, dev->hw_features);
+ ethnl_features_to_bitmap32(data->wanted, dev->wanted_features);
+ ethnl_features_to_bitmap32(data->active, dev->features);
+ ethnl_features_to_bitmap32(data->nochange, NETIF_F_NEVER_CHANGE);
+ all_features = GENMASK_ULL(NETDEV_FEATURE_COUNT - 1, 0);
+ ethnl_features_to_bitmap32(data->all, all_features);
+
+ return 0;
+}
+
+static int features_reply_size(const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct features_reply_data *data = FEATURES_REPDATA(reply_base);
+ bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+ unsigned int len = 0;
+ int ret;
+
+ ret = ethnl_bitset32_size(data->hw, data->all, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ len += ret;
+ ret = ethnl_bitset32_size(data->wanted, NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ len += ret;
+ ret = ethnl_bitset32_size(data->active, NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ len += ret;
+ ret = ethnl_bitset32_size(data->nochange, NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ len += ret;
+
+ return len;
+}
+
+static int features_fill_reply(struct sk_buff *skb,
+ const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct features_reply_data *data = FEATURES_REPDATA(reply_base);
+ bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+ int ret;
+
+ ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_HW, data->hw,
+ data->all, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_WANTED, data->wanted,
+ NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_ACTIVE, data->active,
+ NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+ if (ret < 0)
+ return ret;
+ return ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_NOCHANGE,
+ data->nochange, NULL, NETDEV_FEATURE_COUNT,
+ netdev_features_strings, compact);
+}
+
+const struct ethnl_request_ops ethnl_features_request_ops = {
+ .request_cmd = ETHTOOL_MSG_FEATURES_GET,
+ .reply_cmd = ETHTOOL_MSG_FEATURES_GET_REPLY,
+ .hdr_attr = ETHTOOL_A_FEATURES_HEADER,
+ .max_attr = ETHTOOL_A_FEATURES_MAX,
+ .req_info_size = sizeof(struct features_req_info),
+ .reply_data_size = sizeof(struct features_reply_data),
+ .request_policy = features_get_policy,
+
+ .prepare_data = features_prepare_data,
+ .reply_size = features_reply_size,
+ .fill_reply = features_fill_reply,
+};
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index ae97c82c7052..45d1bf1764b7 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -56,8 +56,6 @@ EXPORT_SYMBOL(ethtool_op_get_ts_info);

/* Handlers for each ethtool command */

-#define ETHTOOL_DEV_FEATURE_WORDS ((NETDEV_FEATURE_COUNT + 31) / 32)
-
static int ethtool_get_features(struct net_device *dev, void __user *useraddr)
{
struct ethtool_gfeatures cmd = {
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 8eca55122ef3..e451a75e9577 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -215,6 +215,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_LINKSTATE_GET] = &ethnl_linkstate_request_ops,
[ETHTOOL_MSG_DEBUG_GET] = &ethnl_debug_request_ops,
[ETHTOOL_MSG_WOL_GET] = &ethnl_wol_request_ops,
+ [ETHTOOL_MSG_FEATURES_GET] = &ethnl_features_request_ops,
};

static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -695,6 +696,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_wol,
},
+ {
+ .cmd = ETHTOOL_MSG_FEATURES_GET,
+ .doit = ethnl_default_doit,
+ .start = ethnl_default_start,
+ .dumpit = ethnl_default_dumpit,
+ .done = ethnl_default_done,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 961708290074..be2325ea8493 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -337,6 +337,7 @@ extern const struct ethnl_request_ops ethnl_linkmodes_request_ops;
extern const struct ethnl_request_ops ethnl_linkstate_request_ops;
extern const struct ethnl_request_ops ethnl_debug_request_ops;
extern const struct ethnl_request_ops ethnl_wol_request_ops;
+extern const struct ethnl_request_ops ethnl_features_request_ops;

int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
--
2.25.1