From 1421bb3e1bcf8b136d2e53885dfe5f7257b5fa48 Mon Sep 17 00:00:00 2001
From: Michal Kubecek <mkubecek@suse.cz>
Date: Thu, 12 Mar 2020 21:08:23 +0100
Subject: [PATCH 163/283] ethtool: provide ring sizes with RINGS_GET request

mainline inclusion
from mainline-v5.7-rc1
commit e4a1717b677c5cb285e9b425c569e261084a484c
category: feature
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I8EN3D

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4a1717b677c5cb285e9b425c569e261084a484c

--------------------------------

Implement RINGS_GET request to get ring sizes of a network device. These
are traditionally available via ETHTOOL_GRINGPARAM ioctl request.

Omit attributes for ring types which are not supported by driver or device
(zero reported for maximum).

v2: (all suggested by Jakub Kicinski)
  - minor cleanup in rings_prepare_data()
  - more descriptive rings_reply_size()
  - omit attributes with zero max size

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xiaodong Li <lixiaodong67@huawei.com>

 Conflicts:
	Documentation/networking/ethtool-netlink.rst
	include/uapi/linux/ethtool_netlink.h
	net/ethtool/Makefile
	net/ethtool/netlink.c
	net/ethtool/netlink.h
---
 Documentation/networking/ethtool-netlink.rst |  38 +-
 include/linux/ethtool_netlink.h              |   4 +
 include/linux/netlink.h                      |  14 +
 include/uapi/linux/ethtool_netlink.h         | 239 +++++++-
 net/ethtool/Makefile                         |   2 +-
 net/ethtool/netlink.c                        | 601 +++++++++++++++++++
 net/ethtool/netlink.h                        | 118 ++++
 net/ethtool/rings.c                          | 108 ++++
 net/netlink/af_netlink.c                     |  12 +-
 9 files changed, 1132 insertions(+), 4 deletions(-)
 create mode 100644 net/ethtool/rings.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index fc550a3e82b1..32a92edfec14 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -175,6 +175,18 @@ according to message purpose:
   ``_NTF``          kernel notification
   ==============    ======================================
 
+Userspace to kernel:
+
+  ===================================== ================================
+  ``ETHTOOL_MSG_RINGS_GET``             get ring sizes
+  ===================================== ================================
+
+Kernel to userspace:
+
+  ===================================== =================================
+  ``ETHTOOL_MSG_RINGS_GET_REPLY``       ring sizes
+  ===================================== =================================
+
 ``GET`` requests are sent by userspace applications to retrieve device
 information. They usually do not contain any message specific attributes.
 Kernel replies with corresponding "GET_REPLY" message. For most types, ``GET``
@@ -205,6 +217,30 @@ an ``ACT_REPLY`` message. Performing an action also triggers a notification
 
 Later sections describe the format and semantics of these messages.
 
+RINGS_GET
+=========
+
+Gets ring sizes like ``ETHTOOL_GRINGPARAM`` ioctl request.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_RINGS_HEADER``            nested  request header
+  ====================================  ======  ==========================
+
+Kernel response contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_RINGS_HEADER``            nested  reply header
+  ``ETHTOOL_A_RINGS_RX_MAX``            u32     max size of RX ring
+  ``ETHTOOL_A_RINGS_RX_MINI_MAX``       u32     max size of RX mini ring
+  ``ETHTOOL_A_RINGS_RX_JUMBO_MAX``      u32     max size of RX jumbo ring
+  ``ETHTOOL_A_RINGS_TX_MAX``            u32     max size of TX ring
+  ``ETHTOOL_A_RINGS_RX``                u32     size of RX ring
+  ``ETHTOOL_A_RINGS_RX_MINI``           u32     size of RX mini ring
+  ``ETHTOOL_A_RINGS_RX_JUMBO``          u32     size of RX jumbo ring
+  ``ETHTOOL_A_RINGS_TX``                u32     size of TX ring
+  ====================================  ======  ==========================
 
 Request translation
 ===================
@@ -230,7 +266,7 @@ have their netlink replacement yet.
   ``ETHTOOL_SEEPROM``                 n/a
   ``ETHTOOL_GCOALESCE``               n/a
   ``ETHTOOL_SCOALESCE``               n/a
-  ``ETHTOOL_GRINGPARAM``              n/a
+  ``ETHTOOL_GRINGPARAM``              ``ETHTOOL_MSG_RINGS_GET``
   ``ETHTOOL_SRINGPARAM``              n/a
   ``ETHTOOL_GPAUSEPARAM``             n/a
   ``ETHTOOL_SPAUSEPARAM``             n/a
diff --git a/include/linux/ethtool_netlink.h b/include/linux/ethtool_netlink.h
index f27e92b5f344..dd9a51057c6f 100644
--- a/include/linux/ethtool_netlink.h
+++ b/include/linux/ethtool_netlink.h
@@ -6,4 +6,8 @@
 #include <uapi/linux/ethtool_netlink.h>
 #include <linux/ethtool.h>
 
+enum ethtool_multicast_groups {
+	ETHNL_MCGRP_MONITOR,
+};
+
 #endif /* _LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 71f121b66ca8..b25b2f427127 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -176,10 +176,24 @@ struct netlink_callback {
 	void			*data;
 	/* the module that dump function belong to */
 	struct module		*module;
+#ifndef __GENKSYMS__
+	struct netlink_ext_ack  *extack;
+#endif
 	u16			family;
 	u16			min_dump_alloc;
 	unsigned int		prev_seq, seq;
+#ifdef __GENKSYMS__
 	long			args[6];
+#else
+	union {
+		u8              ctx[48];
+
+		/* args is deprecated. Cast a struct over ctx instead
+		 * for proper type safety.
+		 */
+		long            args[6];
+	};
+#endif
 };
 
 struct netlink_notify {
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 82fc3b5f41c9..496e1d4805ee 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -14,6 +14,21 @@
 /* message types - userspace to kernel */
 enum {
 	ETHTOOL_MSG_USER_NONE,
+	ETHTOOL_MSG_STRSET_GET,
+	ETHTOOL_MSG_LINKINFO_GET,
+	ETHTOOL_MSG_LINKINFO_SET,
+	ETHTOOL_MSG_LINKMODES_GET,
+	ETHTOOL_MSG_LINKMODES_SET,
+	ETHTOOL_MSG_LINKSTATE_GET,
+	ETHTOOL_MSG_DEBUG_GET,
+	ETHTOOL_MSG_DEBUG_SET,
+	ETHTOOL_MSG_WOL_GET,
+	ETHTOOL_MSG_WOL_SET,
+	ETHTOOL_MSG_FEATURES_GET,
+	ETHTOOL_MSG_FEATURES_SET,
+	ETHTOOL_MSG_PRIVFLAGS_GET,
+	ETHTOOL_MSG_PRIVFLAGS_SET,
+	ETHTOOL_MSG_RINGS_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -23,7 +38,23 @@ enum {
 /* message types - kernel to userspace */
 enum {
 	ETHTOOL_MSG_KERNEL_NONE,
-
+	ETHTOOL_MSG_STRSET_GET_REPLY,
+	ETHTOOL_MSG_LINKINFO_GET_REPLY,
+	ETHTOOL_MSG_LINKINFO_NTF,
+	ETHTOOL_MSG_LINKMODES_GET_REPLY,
+	ETHTOOL_MSG_LINKMODES_NTF,
+	ETHTOOL_MSG_LINKSTATE_GET_REPLY,
+	ETHTOOL_MSG_DEBUG_GET_REPLY,
+	ETHTOOL_MSG_DEBUG_NTF,
+	ETHTOOL_MSG_WOL_GET_REPLY,
+	ETHTOOL_MSG_WOL_NTF,
+	ETHTOOL_MSG_FEATURES_GET_REPLY,
+	ETHTOOL_MSG_FEATURES_SET_REPLY,
+	ETHTOOL_MSG_FEATURES_NTF,
+	ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,
+	ETHTOOL_MSG_PRIVFLAGS_NTF,
+	ETHTOOL_MSG_RINGS_GET_REPLY,
+	ETHTOOL_MSG_RINGS_NTF,
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
 	ETHTOOL_MSG_KERNEL_MAX = __ETHTOOL_MSG_KERNEL_CNT - 1
@@ -50,8 +81,214 @@ enum {
 	ETHTOOL_A_HEADER_MAX = __ETHTOOL_A_HEADER_CNT - 1
 };
 
+/* bit sets */
+
+enum {
+	ETHTOOL_A_BITSET_BIT_UNSPEC,
+	ETHTOOL_A_BITSET_BIT_INDEX,		/* u32 */
+	ETHTOOL_A_BITSET_BIT_NAME,		/* string */
+	ETHTOOL_A_BITSET_BIT_VALUE,		/* flag */
+
+	/* add new constants above here */
+	__ETHTOOL_A_BITSET_BIT_CNT,
+	ETHTOOL_A_BITSET_BIT_MAX = __ETHTOOL_A_BITSET_BIT_CNT - 1
+};
+
+enum {
+	ETHTOOL_A_BITSET_BITS_UNSPEC,
+	ETHTOOL_A_BITSET_BITS_BIT,		/* nest - _A_BITSET_BIT_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_BITSET_BITS_CNT,
+	ETHTOOL_A_BITSET_BITS_MAX = __ETHTOOL_A_BITSET_BITS_CNT - 1
+};
+
+enum {
+	ETHTOOL_A_BITSET_UNSPEC,
+	ETHTOOL_A_BITSET_NOMASK,		/* flag */
+	ETHTOOL_A_BITSET_SIZE,			/* u32 */
+	ETHTOOL_A_BITSET_BITS,			/* nest - _A_BITSET_BITS_* */
+	ETHTOOL_A_BITSET_VALUE,			/* binary */
+	ETHTOOL_A_BITSET_MASK,			/* binary */
+
+	/* add new constants above here */
+	__ETHTOOL_A_BITSET_CNT,
+	ETHTOOL_A_BITSET_MAX = __ETHTOOL_A_BITSET_CNT - 1
+};
+
+/* string sets */
+
+enum {
+	ETHTOOL_A_STRING_UNSPEC,
+	ETHTOOL_A_STRING_INDEX,			/* u32 */
+	ETHTOOL_A_STRING_VALUE,			/* string */
+
+	/* add new constants above here */
+	__ETHTOOL_A_STRING_CNT,
+	ETHTOOL_A_STRING_MAX = __ETHTOOL_A_STRING_CNT - 1
+};
+
+enum {
+	ETHTOOL_A_STRINGS_UNSPEC,
+	ETHTOOL_A_STRINGS_STRING,		/* nest - _A_STRINGS_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_STRINGS_CNT,
+	ETHTOOL_A_STRINGS_MAX = __ETHTOOL_A_STRINGS_CNT - 1
+};
+
+enum {
+	ETHTOOL_A_STRINGSET_UNSPEC,
+	ETHTOOL_A_STRINGSET_ID,			/* u32 */
+	ETHTOOL_A_STRINGSET_COUNT,		/* u32 */
+	ETHTOOL_A_STRINGSET_STRINGS,		/* nest - _A_STRINGS_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_STRINGSET_CNT,
+	ETHTOOL_A_STRINGSET_MAX = __ETHTOOL_A_STRINGSET_CNT - 1
+};
+
+enum {
+	ETHTOOL_A_STRINGSETS_UNSPEC,
+	ETHTOOL_A_STRINGSETS_STRINGSET,		/* nest - _A_STRINGSET_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_STRINGSETS_CNT,
+	ETHTOOL_A_STRINGSETS_MAX = __ETHTOOL_A_STRINGSETS_CNT - 1
+};
+
+/* STRSET */
+
+enum {
+	ETHTOOL_A_STRSET_UNSPEC,
+	ETHTOOL_A_STRSET_HEADER,		/* nest - _A_HEADER_* */
+	ETHTOOL_A_STRSET_STRINGSETS,		/* nest - _A_STRINGSETS_* */
+	ETHTOOL_A_STRSET_COUNTS_ONLY,		/* flag */
+
+	/* add new constants above here */
+	__ETHTOOL_A_STRSET_CNT,
+	ETHTOOL_A_STRSET_MAX = __ETHTOOL_A_STRSET_CNT - 1
+};
+
+/* LINKINFO */
+
+enum {
+	ETHTOOL_A_LINKINFO_UNSPEC,
+	ETHTOOL_A_LINKINFO_HEADER,		/* nest - _A_HEADER_* */
+	ETHTOOL_A_LINKINFO_PORT,		/* u8 */
+	ETHTOOL_A_LINKINFO_PHYADDR,		/* u8 */
+	ETHTOOL_A_LINKINFO_TP_MDIX,		/* u8 */
+	ETHTOOL_A_LINKINFO_TP_MDIX_CTRL,	/* u8 */
+	ETHTOOL_A_LINKINFO_TRANSCEIVER,		/* u8 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_LINKINFO_CNT,
+	ETHTOOL_A_LINKINFO_MAX = __ETHTOOL_A_LINKINFO_CNT - 1
+};
+
+/* LINKMODES */
+
+enum {
+	ETHTOOL_A_LINKMODES_UNSPEC,
+	ETHTOOL_A_LINKMODES_HEADER,		/* nest - _A_HEADER_* */
+	ETHTOOL_A_LINKMODES_AUTONEG,		/* u8 */
+	ETHTOOL_A_LINKMODES_OURS,		/* bitset */
+	ETHTOOL_A_LINKMODES_PEER,		/* bitset */
+	ETHTOOL_A_LINKMODES_SPEED,		/* u32 */
+	ETHTOOL_A_LINKMODES_DUPLEX,		/* u8 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_LINKMODES_CNT,
+	ETHTOOL_A_LINKMODES_MAX = __ETHTOOL_A_LINKMODES_CNT - 1
+};
+
+/* LINKSTATE */
+
+enum {
+	ETHTOOL_A_LINKSTATE_UNSPEC,
+	ETHTOOL_A_LINKSTATE_HEADER,		/* nest - _A_HEADER_* */
+	ETHTOOL_A_LINKSTATE_LINK,		/* u8 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_LINKSTATE_CNT,
+	ETHTOOL_A_LINKSTATE_MAX = __ETHTOOL_A_LINKSTATE_CNT - 1
+};
+
+/* DEBUG */
+
+enum {
+	ETHTOOL_A_DEBUG_UNSPEC,
+	ETHTOOL_A_DEBUG_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_DEBUG_MSGMASK,		/* bitset */
+
+	/* add new constants above here */
+	__ETHTOOL_A_DEBUG_CNT,
+	ETHTOOL_A_DEBUG_MAX = __ETHTOOL_A_DEBUG_CNT - 1
+};
+
+/* WOL */
+
+enum {
+	ETHTOOL_A_WOL_UNSPEC,
+	ETHTOOL_A_WOL_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_WOL_MODES,			/* bitset */
+	ETHTOOL_A_WOL_SOPASS,			/* binary */
+
+	/* add new constants above here */
+	__ETHTOOL_A_WOL_CNT,
+	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
+};
+
+/* 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
+};
+
+/* RINGS */
+
+enum {
+	ETHTOOL_A_RINGS_UNSPEC,
+	ETHTOOL_A_RINGS_HEADER,				/* nest - _A_HEADER_* */
+	ETHTOOL_A_RINGS_RX_MAX,				/* u32 */
+	ETHTOOL_A_RINGS_RX_MINI_MAX,			/* u32 */
+	ETHTOOL_A_RINGS_RX_JUMBO_MAX,			/* u32 */
+	ETHTOOL_A_RINGS_TX_MAX,				/* u32 */
+	ETHTOOL_A_RINGS_RX,				/* u32 */
+	ETHTOOL_A_RINGS_RX_MINI,			/* u32 */
+	ETHTOOL_A_RINGS_RX_JUMBO,			/* u32 */
+	ETHTOOL_A_RINGS_TX,				/* u32 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_RINGS_CNT,
+	ETHTOOL_A_RINGS_MAX = (__ETHTOOL_A_RINGS_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
 
+#define ETHTOOL_MCGRP_MONITOR_NAME "monitor"
+
 #endif /* _UAPI_LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 59d5ee230c29..6f1cdf8a57b3 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -4,4 +4,4 @@ obj-y				+= ioctl.o common.o
 
 obj-$(CONFIG_ETHTOOL_NETLINK)	+= ethtool_nl.o
 
-ethtool_nl-y	:= netlink.o
+ethtool_nl-y	:= netlink.o rings.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index aef882e0c3f5..778bbeb517f5 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -6,6 +6,9 @@
 
 static struct genl_family ethtool_genl_family;
 
+static bool ethnl_ok __read_mostly;
+static u32 ethnl_bcast_seq;
+
 static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
 	[ETHTOOL_A_HEADER_UNSPEC]	= { .type = NLA_REJECT },
 	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
@@ -14,6 +17,85 @@ static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
 	[ETHTOOL_A_HEADER_FLAGS]	= { .type = NLA_U32 },
 };
 
+/**
+ * ethnl_parse_header_dev_get() - parse request header
+ * @req_info:    structure to put results into
+ * @header:      nest attribute with request header
+ * @net:         request netns
+ * @extack:      netlink extack for error reporting
+ * @require_dev: fail if no device identified in header
+ *
+ * Parse request header in nested attribute @nest and puts results into
+ * the structure pointed to by @req_info. Extack from @info is used for error
+ * reporting. If req_info->dev is not null on return, reference to it has
+ * been taken. If error is returned, *req_info is null initialized and no
+ * reference is held.
+ *
+ * Return: 0 on success or negative error code
+ */
+int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
+			       const struct nlattr *header, struct net *net,
+			       struct netlink_ext_ack *extack, bool require_dev)
+{
+	struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
+	const struct nlattr *devname_attr;
+	struct net_device *dev = NULL;
+	int ret;
+
+	if (!header) {
+		NL_SET_ERR_MSG(extack, "request header missing");
+		return -EINVAL;
+	}
+	ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
+			       ethnl_header_policy, extack);
+	if (ret < 0)
+		return ret;
+	devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
+
+	if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
+		u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]);
+
+		dev = dev_get_by_index(net, ifindex);
+		if (!dev) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[ETHTOOL_A_HEADER_DEV_INDEX],
+					    "no device matches ifindex");
+			return -ENODEV;
+		}
+		/* if both ifindex and ifname are passed, they must match */
+		if (devname_attr &&
+		    strncmp(dev->name, nla_data(devname_attr), IFNAMSIZ)) {
+			dev_put(dev);
+			NL_SET_ERR_MSG_ATTR(extack, header,
+					    "ifindex and name do not match");
+			return -ENODEV;
+		}
+	} else if (devname_attr) {
+		dev = dev_get_by_name(net, nla_data(devname_attr));
+		if (!dev) {
+			NL_SET_ERR_MSG_ATTR(extack, devname_attr,
+					    "no device matches name");
+			return -ENODEV;
+		}
+	} else if (require_dev) {
+		NL_SET_ERR_MSG_ATTR(extack, header,
+				    "neither ifindex nor name specified");
+		return -EINVAL;
+	}
+
+	if (dev && !netif_device_present(dev)) {
+		dev_put(dev);
+		NL_SET_ERR_MSG(extack, "device not present");
+		return -ENODEV;
+	}
+
+	req_info->dev = dev;
+	if (tb[ETHTOOL_A_HEADER_FLAGS])
+		req_info->flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);
+
+	return 0;
+}
+
 /**
  * ethnl_parse_header() - parse request header
  * @req_info:    structure to put results into
@@ -169,9 +251,528 @@ struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
 	return NULL;
 }
 
+static void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
+{
+	return genlmsg_put(skb, 0, ++ethnl_bcast_seq, &ethtool_genl_family, 0,
+			   cmd);
+}
+
+static int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
+{
+	return genlmsg_multicast_netns(&ethtool_genl_family, dev_net(dev), skb,
+				       0, ETHNL_MCGRP_MONITOR, GFP_KERNEL);
+}
+
+/* GET request helpers */
+
+/**
+ * struct ethnl_dump_ctx - context structure for generic dumpit() callback
+ * @ops:        request ops of currently processed message type
+ * @req_info:   parsed request header of processed request
+ * @reply_data: data needed to compose the reply
+ * @pos_hash:   saved iteration position - hashbucket
+ * @pos_idx:    saved iteration position - index
+ *
+ * These parameters are kept in struct netlink_callback as context preserved
+ * between iterations. They are initialized by ethnl_default_start() and used
+ * in ethnl_default_dumpit() and ethnl_default_done().
+ */
+struct ethnl_dump_ctx {
+	const struct ethnl_request_ops	*ops;
+	struct ethnl_req_info		*req_info;
+	struct ethnl_reply_data		*reply_data;
+	int				pos_hash;
+	int				pos_idx;
+};
+
+static const struct ethnl_request_ops *
+ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
+	[ETHTOOL_MSG_RINGS_GET]		= &ethnl_rings_request_ops,
+};
+
+static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
+{
+	return (struct ethnl_dump_ctx *)cb->ctx;
+}
+
+/**
+ * ethnl_default_parse() - Parse request message
+ * @req_info:    pointer to structure to put data into
+ * @nlhdr:       pointer to request message header
+ * @net:         request netns
+ * @request_ops: struct request_ops for request type
+ * @extack:      netlink extack for error reporting
+ * @require_dev: fail if no device identified in header
+ *
+ * Parse universal request header and call request specific ->parse_request()
+ * callback (if defined) to parse the rest of the message.
+ *
+ * Return: 0 on success or negative error code
+ */
+static int ethnl_default_parse(struct ethnl_req_info *req_info,
+			       const struct nlmsghdr *nlhdr, struct net *net,
+			       const struct ethnl_request_ops *request_ops,
+			       struct netlink_ext_ack *extack, bool require_dev)
+{
+	struct nlattr **tb;
+	int ret;
+
+	tb = kmalloc_array(request_ops->max_attr + 1, sizeof(tb[0]),
+			   GFP_KERNEL);
+	if (!tb)
+		return -ENOMEM;
+
+	ret = nlmsg_parse(nlhdr, GENL_HDRLEN, tb, request_ops->max_attr,
+			  request_ops->request_policy, extack);
+	if (ret < 0)
+		goto out;
+	ret = ethnl_parse_header_dev_get(req_info, tb[request_ops->hdr_attr],
+					 net, extack, require_dev);
+	if (ret < 0)
+		goto out;
+
+	if (request_ops->parse_request) {
+		ret = request_ops->parse_request(req_info, tb, extack);
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = 0;
+out:
+	kfree(tb);
+	return ret;
+}
+
+/**
+ * ethnl_init_reply_data() - Initialize reply data for GET request
+ * @reply_data: pointer to embedded struct ethnl_reply_data
+ * @ops:        instance of struct ethnl_request_ops describing the layout
+ * @dev:        network device to initialize the reply for
+ *
+ * Fills the reply data part with zeros and sets the dev member. Must be called
+ * before calling the ->fill_reply() callback (for each iteration when handling
+ * dump requests).
+ */
+static void ethnl_init_reply_data(struct ethnl_reply_data *reply_data,
+				  const struct ethnl_request_ops *ops,
+				  struct net_device *dev)
+{
+	memset(reply_data, 0, ops->reply_data_size);
+	reply_data->dev = dev;
+}
+
+/* default ->doit() handler for GET type requests */
+static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct ethnl_reply_data *reply_data = NULL;
+	struct ethnl_req_info *req_info = NULL;
+	const u8 cmd = info->genlhdr->cmd;
+	const struct ethnl_request_ops *ops;
+	struct sk_buff *rskb;
+	void *reply_payload;
+	int reply_len;
+	int ret;
+
+	ops = ethnl_default_requests[cmd];
+	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", cmd))
+		return -EOPNOTSUPP;
+	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
+	if (!req_info)
+		return -ENOMEM;
+	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
+	if (!reply_data) {
+		kfree(req_info);
+		return -ENOMEM;
+	}
+
+	ret = ethnl_default_parse(req_info, info->nlhdr,
+				  genl_info_net(info), ops,
+				  info->extack, !ops->allow_nodev_do);
+	if (ret < 0)
+		goto err_dev;
+	ethnl_init_reply_data(reply_data, ops, req_info->dev);
+
+	rtnl_lock();
+	ret = ops->prepare_data(req_info, reply_data, info);
+	rtnl_unlock();
+	if (ret < 0)
+		goto err_cleanup;
+	ret = ops->reply_size(req_info, reply_data);
+	if (ret < 0)
+		goto err_cleanup;
+	reply_len = ret;
+	ret = -ENOMEM;
+	rskb = ethnl_reply_init(reply_len, req_info->dev, ops->reply_cmd,
+				ops->hdr_attr, info, &reply_payload);
+	if (!rskb)
+		goto err_cleanup;
+	ret = ops->fill_reply(rskb, req_info, reply_data);
+	if (ret < 0)
+		goto err_msg;
+	if (ops->cleanup_data)
+		ops->cleanup_data(reply_data);
+
+	genlmsg_end(rskb, reply_payload);
+	if (req_info->dev)
+		dev_put(req_info->dev);
+	kfree(reply_data);
+	kfree(req_info);
+	return genlmsg_reply(rskb, info);
+
+err_msg:
+	WARN_ONCE(ret == -EMSGSIZE,
+		  "calculated message payload length (%d) not sufficient\n",
+		  reply_len);
+	nlmsg_free(rskb);
+err_cleanup:
+	if (ops->cleanup_data)
+		ops->cleanup_data(reply_data);
+err_dev:
+	if (req_info->dev)
+		dev_put(req_info->dev);
+	kfree(reply_data);
+	kfree(req_info);
+	return ret;
+}
+
+static int ethnl_default_dump_one(struct sk_buff *skb, struct net_device *dev,
+				  const struct ethnl_dump_ctx *ctx)
+{
+	int ret;
+
+	ethnl_init_reply_data(ctx->reply_data, ctx->ops, dev);
+	rtnl_lock();
+	ret = ctx->ops->prepare_data(ctx->req_info, ctx->reply_data, NULL);
+	rtnl_unlock();
+	if (ret < 0)
+		goto out;
+	ret = ethnl_fill_reply_header(skb, dev, ctx->ops->hdr_attr);
+	if (ret < 0)
+		goto out;
+	ret = ctx->ops->fill_reply(skb, ctx->req_info, ctx->reply_data);
+
+out:
+	if (ctx->ops->cleanup_data)
+		ctx->ops->cleanup_data(ctx->reply_data);
+	ctx->reply_data->dev = NULL;
+	return ret;
+}
+
+/* Default ->dumpit() handler for GET requests. Device iteration copied from
+ * rtnl_dump_ifinfo(); we have to be more careful about device hashtable
+ * persistence as we cannot guarantee to hold RTNL lock through the whole
+ * function as rtnetnlink does.
+ */
+static int ethnl_default_dumpit(struct sk_buff *skb,
+				struct netlink_callback *cb)
+{
+	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
+	struct net *net = sock_net(skb->sk);
+	int s_idx = ctx->pos_idx;
+	int h, idx = 0;
+	int ret = 0;
+	void *ehdr;
+
+	rtnl_lock();
+	for (h = ctx->pos_hash; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
+		struct hlist_head *head;
+		struct net_device *dev;
+		unsigned int seq;
+
+		head = &net->dev_index_head[h];
+
+restart_chain:
+		seq = net->dev_base_seq;
+		cb->seq = seq;
+		idx = 0;
+		hlist_for_each_entry(dev, head, index_hlist) {
+			if (idx < s_idx)
+				goto cont;
+			dev_hold(dev);
+			rtnl_unlock();
+
+			ehdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					   cb->nlh->nlmsg_seq,
+					   &ethtool_genl_family, 0,
+					   ctx->ops->reply_cmd);
+			if (!ehdr) {
+				dev_put(dev);
+				ret = -EMSGSIZE;
+				goto out;
+			}
+			ret = ethnl_default_dump_one(skb, dev, ctx);
+			dev_put(dev);
+			if (ret < 0) {
+				genlmsg_cancel(skb, ehdr);
+				if (ret == -EOPNOTSUPP)
+					goto lock_and_cont;
+				if (likely(skb->len))
+					ret = skb->len;
+				goto out;
+			}
+			genlmsg_end(skb, ehdr);
+lock_and_cont:
+			rtnl_lock();
+			if (net->dev_base_seq != seq) {
+				s_idx = idx + 1;
+				goto restart_chain;
+			}
+cont:
+			idx++;
+		}
+	}
+	rtnl_unlock();
+
+out:
+	ctx->pos_hash = h;
+	ctx->pos_idx = idx;
+	nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+
+	return ret;
+}
+
+/* generic ->start() handler for GET requests */
+static int ethnl_default_start(struct netlink_callback *cb)
+{
+	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
+	struct ethnl_reply_data *reply_data;
+	const struct ethnl_request_ops *ops;
+	struct ethnl_req_info *req_info;
+	struct genlmsghdr *ghdr;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	ghdr = nlmsg_data(cb->nlh);
+	ops = ethnl_default_requests[ghdr->cmd];
+	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", ghdr->cmd))
+		return -EOPNOTSUPP;
+	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
+	if (!req_info)
+		return -ENOMEM;
+	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
+	if (!reply_data) {
+		ret = -ENOMEM;
+		goto free_req_info;
+	}
+
+	ret = ethnl_default_parse(req_info, cb->nlh, sock_net(cb->skb->sk), ops,
+				  cb->extack, false);
+	if (req_info->dev) {
+		/* We ignore device specification in dump requests but as the
+		 * same parser as for non-dump (doit) requests is used, it
+		 * would take reference to the device if it finds one
+		 */
+		dev_put(req_info->dev);
+		req_info->dev = NULL;
+	}
+	if (ret < 0)
+		goto free_reply_data;
+
+	ctx->ops = ops;
+	ctx->req_info = req_info;
+	ctx->reply_data = reply_data;
+	ctx->pos_hash = 0;
+	ctx->pos_idx = 0;
+
+	return 0;
+
+free_reply_data:
+	kfree(reply_data);
+free_req_info:
+	kfree(req_info);
+
+	return ret;
+}
+
+/* default ->done() handler for GET requests */
+static int ethnl_default_done(struct netlink_callback *cb)
+{
+	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
+
+	kfree(ctx->reply_data);
+	kfree(ctx->req_info);
+
+	return 0;
+}
+
+static const struct ethnl_request_ops *
+ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
+	[ETHTOOL_MSG_RINGS_NTF]		= &ethnl_rings_request_ops,
+};
+
+/* default notification handler */
+static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
+				 const void *data)
+{
+	struct ethnl_reply_data *reply_data;
+	const struct ethnl_request_ops *ops;
+	struct ethnl_req_info *req_info;
+	struct sk_buff *skb;
+	void *reply_payload;
+	int reply_len;
+	int ret;
+
+	if (WARN_ONCE(cmd > ETHTOOL_MSG_KERNEL_MAX ||
+		      !ethnl_default_notify_ops[cmd],
+		      "unexpected notification type %u\n", cmd))
+		return;
+	ops = ethnl_default_notify_ops[cmd];
+	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
+	if (!req_info)
+		return;
+	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
+	if (!reply_data) {
+		kfree(req_info);
+		return;
+	}
+
+	req_info->dev = dev;
+	req_info->flags |= ETHTOOL_FLAG_COMPACT_BITSETS;
+
+	ethnl_init_reply_data(reply_data, ops, dev);
+	ret = ops->prepare_data(req_info, reply_data, NULL);
+	if (ret < 0)
+		goto err_cleanup;
+	ret = ops->reply_size(req_info, reply_data);
+	if (ret < 0)
+		goto err_cleanup;
+	reply_len = ret;
+	ret = -ENOMEM;
+	skb = genlmsg_new(reply_len, GFP_KERNEL);
+	if (!skb)
+		goto err_cleanup;
+	reply_payload = ethnl_bcastmsg_put(skb, cmd);
+	if (!reply_payload)
+		goto err_skb;
+	ret = ethnl_fill_reply_header(skb, dev, ops->hdr_attr);
+	if (ret < 0)
+		goto err_msg;
+	ret = ops->fill_reply(skb, req_info, reply_data);
+	if (ret < 0)
+		goto err_msg;
+	if (ops->cleanup_data)
+		ops->cleanup_data(reply_data);
+
+	genlmsg_end(skb, reply_payload);
+	kfree(reply_data);
+	kfree(req_info);
+	ethnl_multicast(skb, dev);
+	return;
+
+err_msg:
+	WARN_ONCE(ret == -EMSGSIZE,
+		  "calculated message payload length (%d) not sufficient\n",
+		  reply_len);
+err_skb:
+	nlmsg_free(skb);
+err_cleanup:
+	if (ops->cleanup_data)
+		ops->cleanup_data(reply_data);
+	kfree(reply_data);
+	kfree(req_info);
+}
+
+/* notifications */
+
+typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
+				       const void *data);
+
+static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
+	[ETHTOOL_MSG_LINKINFO_NTF]	= ethnl_default_notify,
+	[ETHTOOL_MSG_LINKMODES_NTF]	= ethnl_default_notify,
+	[ETHTOOL_MSG_DEBUG_NTF]		= ethnl_default_notify,
+	[ETHTOOL_MSG_WOL_NTF]		= ethnl_default_notify,
+	[ETHTOOL_MSG_FEATURES_NTF]	= ethnl_default_notify,
+	[ETHTOOL_MSG_PRIVFLAGS_NTF]	= ethnl_default_notify,
+};
+
+void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
+{
+	if (unlikely(!ethnl_ok))
+		return;
+	ASSERT_RTNL();
+
+	if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
+		   ethnl_notify_handlers[cmd]))
+		ethnl_notify_handlers[cmd](dev, cmd, data);
+	else
+		WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
+			  cmd, netdev_name(dev));
+}
+EXPORT_SYMBOL(ethtool_notify);
+
 /* genetlink setup */
 
 static const struct genl_ops ethtool_genl_ops[] = {
+	{
+		.cmd	= ETHTOOL_MSG_STRSET_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_LINKINFO_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_LINKMODES_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_LINKSTATE_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_DEBUG_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_WOL_GET,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_FEATURES_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_PRIVFLAGS_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_RINGS_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[] = {
+	[ETHNL_MCGRP_MONITOR] = { .name = ETHTOOL_MCGRP_MONITOR_NAME },
 };
 
 static struct genl_family ethtool_genl_family = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 05d7183da894..c89b1f6254ba 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -212,4 +212,122 @@ struct ethnl_req_info {
 	u32			flags;
 };
 
+/**
+ * struct ethnl_reply_data - base type of reply data for GET requests
+ * @dev:       device for current reply message; in single shot requests it is
+ *             equal to &ethnl_req_info.dev; in dumps it's different for each
+ *             reply message
+ *
+ * This is a common base for request specific structures holding data for
+ * kernel reply message. These always embed struct ethnl_reply_data at zero
+ * offset.
+ */
+struct ethnl_reply_data {
+	struct net_device		*dev;
+};
+
+static inline int ethnl_ops_begin(struct net_device *dev)
+{
+	if (dev && dev->ethtool_ops->begin)
+		return dev->ethtool_ops->begin(dev);
+	else
+		return 0;
+}
+
+static inline void ethnl_ops_complete(struct net_device *dev)
+{
+	if (dev && dev->ethtool_ops->complete)
+		dev->ethtool_ops->complete(dev);
+}
+
+/**
+ * struct ethnl_request_ops - unified handling of GET requests
+ * @request_cmd:      command id for request (GET)
+ * @reply_cmd:        command id for reply (GET_REPLY)
+ * @hdr_attr:         attribute type for request header
+ * @max_attr:         maximum (top level) attribute type
+ * @req_info_size:    size of request info
+ * @reply_data_size:  size of reply data
+ * @request_policy:   netlink policy for message contents
+ * @allow_nodev_do:   allow non-dump request with no device identification
+ * @parse_request:
+ *	Parse request except common header (struct ethnl_req_info). Common
+ *	header is already filled on entry, the rest up to @repdata_offset
+ *	is zero initialized. This callback should only modify type specific
+ *	request info by parsed attributes from request message.
+ * @prepare_data:
+ *	Retrieve and prepare data needed to compose a reply message. Calls to
+ *	ethtool_ops handlers are limited to this callback. Common reply data
+ *	(struct ethnl_reply_data) is filled on entry, type specific part after
+ *	it is zero initialized. This callback should only modify the type
+ *	specific part of reply data. Device identification from struct
+ *	ethnl_reply_data is to be used as for dump requests, it iterates
+ *	through network devices while dev member of struct ethnl_req_info
+ *	points to the device from client request.
+ * @reply_size:
+ *	Estimate reply message size. Returned value must be sufficient for
+ *	message payload without common reply header. The callback may returned
+ *	estimate higher than actual message size if exact calculation would
+ *	not be worth the saved memory space.
+ * @fill_reply:
+ *	Fill reply message payload (except for common header) from reply data.
+ *	The callback must not generate more payload than previously called
+ *	->reply_size() estimated.
+ * @cleanup_data:
+ *	Optional cleanup called when reply data is no longer needed. Can be
+ *	used e.g. to free any additional data structures outside the main
+ *	structure which were allocated by ->prepare_data(). When processing
+ *	dump requests, ->cleanup() is called for each message.
+ *
+ * Description of variable parts of GET request handling when using the
+ * unified infrastructure. When used, a pointer to an instance of this
+ * structure is to be added to &ethnl_default_requests array and generic
+ * handlers ethnl_default_doit(), ethnl_default_dumpit(),
+ * ethnl_default_start() and ethnl_default_done() used in @ethtool_genl_ops;
+ * ethnl_default_notify() can be used in @ethnl_notify_handlers to send
+ * notifications of the corresponding type.
+ */
+struct ethnl_request_ops {
+	u8			request_cmd;
+	u8			reply_cmd;
+	u16			hdr_attr;
+	unsigned int		max_attr;
+	unsigned int		req_info_size;
+	unsigned int		reply_data_size;
+	const struct nla_policy *request_policy;
+	bool			allow_nodev_do;
+
+	int (*parse_request)(struct ethnl_req_info *req_info,
+			     struct nlattr **tb,
+			     struct netlink_ext_ack *extack);
+	int (*prepare_data)(const struct ethnl_req_info *req_info,
+			    struct ethnl_reply_data *reply_data,
+			    struct genl_info *info);
+	int (*reply_size)(const struct ethnl_req_info *req_info,
+			  const struct ethnl_reply_data *reply_data);
+	int (*fill_reply)(struct sk_buff *skb,
+			  const struct ethnl_req_info *req_info,
+			  const struct ethnl_reply_data *reply_data);
+	void (*cleanup_data)(struct ethnl_reply_data *reply_data);
+};
+
+/* request handlers */
+
+extern const struct ethnl_request_ops ethnl_strset_request_ops;
+extern const struct ethnl_request_ops ethnl_linkinfo_request_ops;
+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;
+extern const struct ethnl_request_ops ethnl_privflags_request_ops;
+extern const struct ethnl_request_ops ethnl_rings_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);
+int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info);
+int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info);
+int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
+int ethnl_set_privflags(struct sk_buff *skb, struct genl_info *info);
+
 #endif /* _NET_ETHTOOL_NETLINK_H */
diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
new file mode 100644
index 000000000000..d3129d8a252d
--- /dev/null
+++ b/net/ethtool/rings.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+
+struct rings_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct rings_reply_data {
+	struct ethnl_reply_data		base;
+	struct ethtool_ringparam	ringparam;
+};
+
+#define RINGS_REPDATA(__reply_base) \
+	container_of(__reply_base, struct rings_reply_data, base)
+
+static const struct nla_policy
+rings_get_policy[ETHTOOL_A_RINGS_MAX + 1] = {
+	[ETHTOOL_A_RINGS_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_HEADER]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_RINGS_RX_MAX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_RX_MINI_MAX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_RX_JUMBO_MAX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_TX_MAX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_RX]			= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_RX_MINI]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_RX_JUMBO]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_RINGS_TX]			= { .type = NLA_REJECT },
+};
+
+static int rings_prepare_data(const struct ethnl_req_info *req_base,
+			      struct ethnl_reply_data *reply_base,
+			      struct genl_info *info)
+{
+	struct rings_reply_data *data = RINGS_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	if (!dev->ethtool_ops->get_ringparam)
+		return -EOPNOTSUPP;
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	dev->ethtool_ops->get_ringparam(dev, &data->ringparam);
+	ethnl_ops_complete(dev);
+
+	return 0;
+}
+
+static int rings_reply_size(const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	return nla_total_size(sizeof(u32)) +	/* _RINGS_RX_MAX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_MINI_MAX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_JUMBO_MAX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_TX_MAX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_MINI */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_JUMBO */
+	       nla_total_size(sizeof(u32));	/* _RINGS_TX */
+}
+
+static int rings_fill_reply(struct sk_buff *skb,
+			    const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	const struct rings_reply_data *data = RINGS_REPDATA(reply_base);
+	const struct ethtool_ringparam *ringparam = &data->ringparam;
+
+	if ((ringparam->rx_max_pending &&
+	     (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MAX,
+			  ringparam->rx_max_pending) ||
+	      nla_put_u32(skb, ETHTOOL_A_RINGS_RX,
+			  ringparam->rx_pending))) ||
+	    (ringparam->rx_mini_max_pending &&
+	     (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MINI_MAX,
+			  ringparam->rx_mini_max_pending) ||
+	      nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MINI,
+			  ringparam->rx_mini_pending))) ||
+	    (ringparam->rx_jumbo_max_pending &&
+	     (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_JUMBO_MAX,
+			  ringparam->rx_jumbo_max_pending) ||
+	      nla_put_u32(skb, ETHTOOL_A_RINGS_RX_JUMBO,
+			  ringparam->rx_jumbo_pending))) ||
+	    (ringparam->tx_max_pending &&
+	     (nla_put_u32(skb, ETHTOOL_A_RINGS_TX_MAX,
+			  ringparam->tx_max_pending) ||
+	      nla_put_u32(skb, ETHTOOL_A_RINGS_TX,
+			  ringparam->tx_pending))))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+const struct ethnl_request_ops ethnl_rings_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_RINGS_GET,
+	.reply_cmd		= ETHTOOL_MSG_RINGS_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_RINGS_HEADER,
+	.max_attr		= ETHTOOL_A_RINGS_MAX,
+	.req_info_size		= sizeof(struct rings_req_info),
+	.reply_data_size	= sizeof(struct rings_reply_data),
+	.request_policy		= rings_get_policy,
+
+	.prepare_data		= rings_prepare_data,
+	.reply_size		= rings_reply_size,
+	.fill_reply		= rings_fill_reply,
+};
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6b5be7a426ac..135b658f060d 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2198,6 +2198,7 @@ EXPORT_SYMBOL(__nlmsg_put);
 static int netlink_dump(struct sock *sk)
 {
 	struct netlink_sock *nlk = nlk_sk(sk);
+	struct netlink_ext_ack extack = {};
 	struct netlink_callback *cb;
 	struct sk_buff *skb = NULL;
 	struct nlmsghdr *nlh;
@@ -2256,8 +2257,11 @@ static int netlink_dump(struct sock *sk)
 
 	netlink_skb_set_owner_r(skb, sk);
 
-	if (nlk->dump_done_errno > 0)
+	if (nlk->dump_done_errno > 0) {
+		cb->extack = &extack;
 		nlk->dump_done_errno = cb->dump(skb, cb);
+		cb->extack = NULL;
+	}
 
 	if (nlk->dump_done_errno > 0 ||
 	    skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
@@ -2280,6 +2284,12 @@ static int netlink_dump(struct sock *sk)
 	memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
 	       sizeof(nlk->dump_done_errno));
 
+	if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {
+		nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
+		if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))
+			nlmsg_end(skb, nlh);
+	}
+
 	if (sk_filter(sk, skb))
 		kfree_skb(skb);
 	else
-- 
2.34.1

