[PATCH net-next 11/15] ethtool: set device ring sizes with RINGS_SET request

From: Michal Kubecek
Date: Wed Mar 11 2020 - 17:41:04 EST


Implement RINGS_SET netlink request to set ring sizes of a network device.
These are traditionally set with ETHTOOL_SRINGPARAM ioctl request.

Like the ioctl implementation, the generic ethtool code checks if supplied
values do not exceed driver defined limits; if they do, first offending
attribute is reported using extack.

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 23 +++++-
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/netlink.c | 5 ++
net/ethtool/netlink.h | 1 +
net/ethtool/rings.c | 87 ++++++++++++++++++++
5 files changed, 116 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 798c2f97d89b..ba31ae8f1feb 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -194,6 +194,7 @@ Userspace to kernel:
``ETHTOOL_MSG_PRIVFLAGS_GET`` get private flags
``ETHTOOL_MSG_PRIVFLAGS_SET`` set private flags
``ETHTOOL_MSG_RINGS_GET`` get ring sizes
+ ``ETHTOOL_MSG_RINGS_SET`` set ring sizes
===================================== ================================

Kernel to userspace:
@@ -673,6 +674,26 @@ Kernel response contents:
==================================== ====== ==========================


+RINGS_SET
+=========
+
+Sets ring sizes like ``ETHTOOL_SRINGPARAM`` ioctl request.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_RINGS_HEADER`` nested reply header
+ ``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
+ ==================================== ====== ==========================
+
+Kernel checks that requested ring sizes do not exceed limits reported by
+driver. Driver may impose additional constraints and may not suspport all
+attributes.
+
+
Request translation
===================

@@ -700,7 +721,7 @@ have their netlink replacement yet.
``ETHTOOL_GCOALESCE`` n/a
``ETHTOOL_SCOALESCE`` n/a
``ETHTOOL_GRINGPARAM`` ``ETHTOOL_MSG_RINGS_GET``
- ``ETHTOOL_SRINGPARAM`` n/a
+ ``ETHTOOL_SRINGPARAM`` ``ETHTOOL_MSG_RINGS_SET``
``ETHTOOL_GPAUSEPARAM`` n/a
``ETHTOOL_SPAUSEPARAM`` n/a
``ETHTOOL_GRXCSUM`` ``ETHTOOL_MSG_FEATURES_GET``
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 7cd220f8cf73..ae71801b7aac 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -29,6 +29,7 @@ enum {
ETHTOOL_MSG_PRIVFLAGS_GET,
ETHTOOL_MSG_PRIVFLAGS_SET,
ETHTOOL_MSG_RINGS_GET,
+ ETHTOOL_MSG_RINGS_SET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 0dc25a490450..6a1ac8897a7e 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -756,6 +756,11 @@ static const struct genl_ops ethtool_genl_ops[] = {
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
+ {
+ .cmd = ETHTOOL_MSG_RINGS_SET,
+ .flags = GENL_UNS_ADMIN_PERM,
+ .doit = ethnl_set_rings,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 01761932ed15..b30426d01890 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -347,5 +347,6 @@ 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);
+int ethnl_set_rings(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
index 945b2323daff..56e628456619 100644
--- a/net/ethtool/rings.c
+++ b/net/ethtool/rings.c
@@ -97,3 +97,90 @@ const struct ethnl_request_ops ethnl_rings_request_ops = {
.reply_size = rings_reply_size,
.fill_reply = rings_fill_reply,
};
+
+/* RINGS_SET */
+
+static const struct nla_policy
+rings_set_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_U32 },
+ [ETHTOOL_A_RINGS_RX_MINI] = { .type = NLA_U32 },
+ [ETHTOOL_A_RINGS_RX_JUMBO] = { .type = NLA_U32 },
+ [ETHTOOL_A_RINGS_TX] = { .type = NLA_U32 },
+};
+
+int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info)
+{
+ struct nlattr *tb[ETHTOOL_A_RINGS_MAX + 1];
+ struct ethtool_ringparam ringparam = {};
+ struct ethnl_req_info req_info = {};
+ const struct nlattr *err_attr;
+ const struct ethtool_ops *ops;
+ struct net_device *dev;
+ bool mod = false;
+ int ret;
+
+ ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
+ ETHTOOL_A_RINGS_MAX, rings_set_policy,
+ info->extack);
+ if (ret < 0)
+ return ret;
+ ret = ethnl_parse_header_dev_get(&req_info,
+ tb[ETHTOOL_A_RINGS_HEADER],
+ genl_info_net(info), info->extack,
+ true);
+ if (ret < 0)
+ return ret;
+ dev = req_info.dev;
+ ops = dev->ethtool_ops;
+ if (!ops->get_ringparam || !ops->set_ringparam)
+ return -EOPNOTSUPP;
+
+ rtnl_lock();
+ ret = ethnl_ops_begin(dev);
+ if (ret < 0)
+ goto out_rtnl;
+ ops->get_ringparam(dev, &ringparam);
+
+ ethnl_update_u32(&ringparam.rx_pending, tb[ETHTOOL_A_RINGS_RX], &mod);
+ ethnl_update_u32(&ringparam.rx_mini_pending,
+ tb[ETHTOOL_A_RINGS_RX_MINI], &mod);
+ ethnl_update_u32(&ringparam.rx_jumbo_pending,
+ tb[ETHTOOL_A_RINGS_RX_JUMBO], &mod);
+ ethnl_update_u32(&ringparam.tx_pending, tb[ETHTOOL_A_RINGS_TX], &mod);
+ ret = 0;
+ if (!mod)
+ goto out_ops;
+
+ /* ensure new ring parameters are within limits */
+ if (ringparam.rx_pending > ringparam.rx_max_pending)
+ err_attr = tb[ETHTOOL_A_RINGS_RX];
+ else if (ringparam.rx_mini_pending > ringparam.rx_mini_max_pending)
+ err_attr = tb[ETHTOOL_A_RINGS_RX_MINI];
+ else if (ringparam.rx_jumbo_pending > ringparam.rx_jumbo_max_pending)
+ err_attr = tb[ETHTOOL_A_RINGS_RX_JUMBO];
+ else if (ringparam.tx_pending > ringparam.tx_max_pending)
+ err_attr = tb[ETHTOOL_A_RINGS_TX];
+ else
+ err_attr = NULL;
+ if (err_attr) {
+ ret = -EINVAL;
+ NL_SET_ERR_MSG_ATTR(info->extack, err_attr,
+ "requested ring size exceeeds maximum");
+ goto out_ops;
+ }
+
+ ret = dev->ethtool_ops->set_ringparam(dev, &ringparam);
+
+out_ops:
+ ethnl_ops_complete(dev);
+out_rtnl:
+ rtnl_unlock();
+ dev_put(dev);
+ return ret;
+}
--
2.25.1