ethtool: provide pause parameters with PAUSE_GET request

Implement PAUSE_GET request to get pause parameters of a network device.
These are traditionally available via ETHTOOL_GPAUSEPARAM ioctl request.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 91 insertions, 1 deletions

diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 7f7f40e03d16..28589ad5fd8a 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -6,4 +6,4 @@ 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
+		   channels.o coalesce.o pause.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 117971e695ca..ca1695de8c9d 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -228,6 +228,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_RINGS_GET]		= &ethnl_rings_request_ops,
 	[ETHTOOL_MSG_CHANNELS_GET]	= &ethnl_channels_request_ops,
 	[ETHTOOL_MSG_COALESCE_GET]	= &ethnl_coalesce_request_ops,
+	[ETHTOOL_MSG_PAUSE_GET]		= &ethnl_pause_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -801,6 +802,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_coalesce,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PAUSE_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 c3fb4fe5a3b7..e14ac089bfb1 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -342,6 +342,7 @@ extern const struct ethnl_request_ops ethnl_privflags_request_ops;
 extern const struct ethnl_request_ops ethnl_rings_request_ops;
 extern const struct ethnl_request_ops ethnl_channels_request_ops;
 extern const struct ethnl_request_ops ethnl_coalesce_request_ops;
+extern const struct ethnl_request_ops ethnl_pause_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/pause.c b/net/ethtool/pause.c
new file mode 100644
index 000000000000..9feafeb7bb1c
--- /dev/null
+++ b/net/ethtool/pause.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+
+struct pause_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct pause_reply_data {
+	struct ethnl_reply_data		base;
+	struct ethtool_pauseparam	pauseparam;
+};
+
+#define PAUSE_REPDATA(__reply_base) \
+	container_of(__reply_base, struct pause_reply_data, base)
+
+static const struct nla_policy
+pause_get_policy[ETHTOOL_A_PAUSE_MAX + 1] = {
+	[ETHTOOL_A_PAUSE_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_PAUSE_HEADER]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_PAUSE_AUTONEG]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_PAUSE_RX]			= { .type = NLA_REJECT },
+	[ETHTOOL_A_PAUSE_TX]			= { .type = NLA_REJECT },
+};
+
+static int pause_prepare_data(const struct ethnl_req_info *req_base,
+			      struct ethnl_reply_data *reply_base,
+			      struct genl_info *info)
+{
+	struct pause_reply_data *data = PAUSE_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	if (!dev->ethtool_ops->get_pauseparam)
+		return -EOPNOTSUPP;
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	dev->ethtool_ops->get_pauseparam(dev, &data->pauseparam);
+	ethnl_ops_complete(dev);
+
+	return 0;
+}
+
+static int pause_reply_size(const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	return nla_total_size(sizeof(u8)) +	/* _PAUSE_AUTONEG */
+		nla_total_size(sizeof(u8)) +	/* _PAUSE_RX */
+		nla_total_size(sizeof(u8));	/* _PAUSE_TX */
+}
+
+static int pause_fill_reply(struct sk_buff *skb,
+			    const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	const struct pause_reply_data *data = PAUSE_REPDATA(reply_base);
+	const struct ethtool_pauseparam *pauseparam = &data->pauseparam;
+
+	if (nla_put_u8(skb, ETHTOOL_A_PAUSE_AUTONEG, !!pauseparam->autoneg) ||
+	    nla_put_u8(skb, ETHTOOL_A_PAUSE_RX, !!pauseparam->rx_pause) ||
+	    nla_put_u8(skb, ETHTOOL_A_PAUSE_TX, !!pauseparam->tx_pause))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+const struct ethnl_request_ops ethnl_pause_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PAUSE_GET,
+	.reply_cmd		= ETHTOOL_MSG_PAUSE_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_PAUSE_HEADER,
+	.max_attr		= ETHTOOL_A_PAUSE_MAX,
+	.req_info_size		= sizeof(struct pause_req_info),
+	.reply_data_size	= sizeof(struct pause_reply_data),
+	.request_policy		= pause_get_policy,
+
+	.prepare_data		= pause_prepare_data,
+	.reply_size		= pause_reply_size,
+	.fill_reply		= pause_fill_reply,
+};