[PATCH net-next v2 07/15] ethtool: provide private flags with PRIVFLAGS_GET request

From: Michal Kubecek
Date: Thu Mar 12 2020 - 16:08:15 EST

Implement PRIVFLAGS_GET request to get private flags for a network device.
These are traditionally available via ETHTOOL_GPFLAGS ioctl request.

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 30 +++-
include/uapi/linux/ethtool_netlink.h | 14 ++
net/ethtool/Makefile | 2 +-
net/ethtool/netlink.c | 8 ++
net/ethtool/netlink.h | 1 +
net/ethtool/privflags.c | 136 +++++++++++++++++++
6 files changed, 189 insertions(+), 2 deletions(-)
create mode 100644 net/ethtool/privflags.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 47542f042e9d..7bba4c940ef7 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -191,6 +191,7 @@ Userspace to kernel:
``ETHTOOL_MSG_WOL_SET`` set wake-on-lan settings
``ETHTOOL_MSG_FEATURES_GET`` get device features
``ETHTOOL_MSG_FEATURES_SET`` set device features
+ ``ETHTOOL_MSG_PRIVFLAGS_GET`` get private flags
===================================== ================================

Kernel to userspace:
@@ -209,6 +210,7 @@ Kernel to userspace:
``ETHTOOL_MSG_FEATURES_GET_REPLY`` device features
``ETHTOOL_MSG_FEATURES_SET_REPLY`` optional reply to FEATURES_SET
``ETHTOOL_MSG_FEATURES_NTF`` netdev features notification
+ ``ETHTOOL_MSG_PRIVFLAGS_GET_REPLY`` private flags
===================================== =================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -598,6 +600,32 @@ request but also each time features are modified with netdev_update_features()
or netdev_change_features().


+PRIVFLAGS_GET
+=============
+
+Gets private flags like ``ETHTOOL_GPFLAGS`` ioctl request.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_PRIVFLAGS_HEADER`` nested request header
+ ==================================== ====== ==========================
+
+Kernel response contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_PRIVFLAGS_HEADER`` nested reply header
+ ``ETHTOOL_A_PRIVFLAGS_FLAGS`` bitset private flags
+ ==================================== ====== ==========================
+
+``ETHTOOL_A_PRIVFLAGS_FLAGS`` is a bitset with values of device private flags.
+These flags are defined by driver, their number and names (and also meaning)
+are device dependent. For compact bitset format, names can be retrieved as
+``ETH_SS_PRIV_FLAGS`` string set. If verbose bitset format is requested,
+response uses all private flags supported by the device as mask so that client
+gets the full information without having to fetch the string set with names.
+
+
Request translation
===================

@@ -647,7 +675,7 @@ have their netlink replacement yet.
``ETHTOOL_SGSO`` ``ETHTOOL_MSG_FEATURES_SET``
``ETHTOOL_GFLAGS`` ``ETHTOOL_MSG_FEATURES_GET``
``ETHTOOL_SFLAGS`` ``ETHTOOL_MSG_FEATURES_SET``
- ``ETHTOOL_GPFLAGS`` n/a
+ ``ETHTOOL_GPFLAGS`` ``ETHTOOL_MSG_PRIVFLAGS_GET``
``ETHTOOL_SPFLAGS`` n/a
``ETHTOOL_GRXFH`` n/a
``ETHTOOL_SRXFH`` n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 3d0204cf96a6..d94bbf5e4d1c 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -26,6 +26,7 @@ enum {
ETHTOOL_MSG_WOL_SET,
ETHTOOL_MSG_FEATURES_GET,
ETHTOOL_MSG_FEATURES_SET,
+ ETHTOOL_MSG_PRIVFLAGS_GET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
@@ -48,6 +49,7 @@ enum {
ETHTOOL_MSG_FEATURES_GET_REPLY,
ETHTOOL_MSG_FEATURES_SET_REPLY,
ETHTOOL_MSG_FEATURES_NTF,
+ ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
@@ -248,6 +250,18 @@ enum {
ETHTOOL_A_FEATURES_MAX = __ETHTOOL_A_FEATURES_CNT - 1
};

+/* PRIVFLAGS */
+
+enum {
+ ETHTOOL_A_PRIVFLAGS_UNSPEC,
+ ETHTOOL_A_PRIVFLAGS_HEADER, /* nest - _A_HEADER_* */
+ ETHTOOL_A_PRIVFLAGS_FLAGS, /* bitset */
+
+ /* add new constants above here */
+ __ETHTOOL_A_PRIVFLAGS_CNT,
+ ETHTOOL_A_PRIVFLAGS_MAX = __ETHTOOL_A_PRIVFLAGS_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 5be8c9ab26d1..58708bcc2968 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 features.o
+ linkstate.o debug.o wol.o features.o privflags.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 5c0e361bfd66..9cbb1d8b4d23 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -216,6 +216,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_DEBUG_GET] = &ethnl_debug_request_ops,
[ETHTOOL_MSG_WOL_GET] = &ethnl_wol_request_ops,
[ETHTOOL_MSG_FEATURES_GET] = &ethnl_features_request_ops,
+ [ETHTOOL_MSG_PRIVFLAGS_GET] = &ethnl_privflags_request_ops,
};

static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -733,6 +734,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_features,
},
+ {
+ .cmd = ETHTOOL_MSG_PRIVFLAGS_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 135836201e89..36cf077c3085 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -338,6 +338,7 @@ 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;
+extern const struct ethnl_request_ops ethnl_privflags_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);
diff --git a/net/ethtool/privflags.c b/net/ethtool/privflags.c
new file mode 100644
index 000000000000..169dd4a832f6
--- /dev/null
+++ b/net/ethtool/privflags.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+#include "bitset.h"
+
+struct privflags_req_info {
+ struct ethnl_req_info base;
+};
+
+struct privflags_reply_data {
+ struct ethnl_reply_data base;
+ const char (*priv_flag_names)[ETH_GSTRING_LEN];
+ unsigned int n_priv_flags;
+ u32 priv_flags;
+};
+
+#define PRIVFLAGS_REPDATA(__reply_base) \
+ container_of(__reply_base, struct privflags_reply_data, base)
+
+static const struct nla_policy
+privflags_get_policy[ETHTOOL_A_PRIVFLAGS_MAX + 1] = {
+ [ETHTOOL_A_PRIVFLAGS_UNSPEC] = { .type = NLA_REJECT },
+ [ETHTOOL_A_PRIVFLAGS_HEADER] = { .type = NLA_NESTED },
+ [ETHTOOL_A_PRIVFLAGS_FLAGS] = { .type = NLA_REJECT },
+};
+
+static int ethnl_get_priv_flags_info(struct net_device *dev,
+ unsigned int *count,
+ const char (**names)[ETH_GSTRING_LEN])
+{
+ const struct ethtool_ops *ops = dev->ethtool_ops;
+ int nflags;
+
+ nflags = ops->get_sset_count(dev, ETH_SS_PRIV_FLAGS);
+ if (nflags < 0)
+ return nflags;
+
+ if (names) {
+ *names = kcalloc(nflags, ETH_GSTRING_LEN, GFP_KERNEL);
+ if (!*names)
+ return -ENOMEM;
+ ops->get_strings(dev, ETH_SS_PRIV_FLAGS, (u8 *)*names);
+ }
+
+ /* We can pass more than 32 private flags to userspace via netlink but
+ * we cannot get more with ethtool_ops::get_priv_flags(). Note that we
+ * must not adjust nflags before allocating the space for flag names
+ * as the buffer must be large enough for all flags.
+ */
+ if (WARN_ONCE(nflags > 32,
+ "device %s reports more than 32 private flags (%d)\n",
+ netdev_name(dev), nflags))
+ nflags = 32;
+ *count = nflags;
+
+ return 0;
+}
+
+static int privflags_prepare_data(const struct ethnl_req_info *req_base,
+ struct ethnl_reply_data *reply_base,
+ struct genl_info *info)
+{
+ struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
+ struct net_device *dev = reply_base->dev;
+ const char (*names)[ETH_GSTRING_LEN];
+ const struct ethtool_ops *ops;
+ unsigned int nflags;
+ int ret;
+
+ ops = dev->ethtool_ops;
+ if (!ops->get_priv_flags || !ops->get_sset_count || !ops->get_strings)
+ return -EOPNOTSUPP;
+ ret = ethnl_ops_begin(dev);
+ if (ret < 0)
+ return ret;
+
+ ret = ethnl_get_priv_flags_info(dev, &nflags, &names);
+ if (ret < 0)
+ goto out_ops;
+ data->priv_flags = ops->get_priv_flags(dev);
+ data->priv_flag_names = names;
+ data->n_priv_flags = nflags;
+
+out_ops:
+ ethnl_ops_complete(dev);
+ return ret;
+}
+
+static int privflags_reply_size(const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
+ bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+ const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);
+
+ return ethnl_bitset32_size(&data->priv_flags, &all_flags,
+ data->n_priv_flags,
+ data->priv_flag_names, compact);
+}
+
+static int privflags_fill_reply(struct sk_buff *skb,
+ const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
+ bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+ const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);
+
+ return ethnl_put_bitset32(skb, ETHTOOL_A_PRIVFLAGS_FLAGS,
+ &data->priv_flags, &all_flags,
+ data->n_priv_flags, data->priv_flag_names,
+ compact);
+}
+
+static void privflags_cleanup_data(struct ethnl_reply_data *reply_data)
+{
+ struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_data);
+
+ kfree(data->priv_flag_names);
+}
+
+const struct ethnl_request_ops ethnl_privflags_request_ops = {
+ .request_cmd = ETHTOOL_MSG_PRIVFLAGS_GET,
+ .reply_cmd = ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,
+ .hdr_attr = ETHTOOL_A_PRIVFLAGS_HEADER,
+ .max_attr = ETHTOOL_A_PRIVFLAGS_MAX,
+ .req_info_size = sizeof(struct privflags_req_info),
+ .reply_data_size = sizeof(struct privflags_reply_data),
+ .request_policy = privflags_get_policy,
+
+ .prepare_data = privflags_prepare_data,
+ .reply_size = privflags_reply_size,
+ .fill_reply = privflags_fill_reply,
+ .cleanup_data = privflags_cleanup_data,
+};
--
2.25.1