Re: [PATCH net-next 4/6] rtnetlink: Add support for SyncE recovered clock configuration

[Roopa Prabhu <roopa@xxxxxxxxxx>]

On 11/4/21 1:12 AM, Maciej Machnikowski wrote:
> Add support for RTNL messages for reading/configuring SyncE recovered
> clocks.
> The messages are:
> RTM_GETRCLKRANGE: Reads the allowed pin index range for the recovered
> 		  clock outputs. This can be aligned to PHY outputs or
> 		  to EEC inputs, whichever is better for a given
> 		  application
>
> RTM_GETRCLKSTATE: Read the state of recovered pins that output recovered
> 		  clock from a given port. The message will contain the
> 		  number of assigned clocks (IFLA_RCLK_STATE_COUNT) and
> 		  a N pin inexes in IFLA_RCLK_STATE_OUT_IDX
>
> RTM_SETRCLKSTATE: Sets the redirection of the recovered clock for
> 		  a given pin
>
> Signed-off-by: Maciej Machnikowski <maciej.machnikowski@xxxxxxxxx>
> ---


Can't we just use a single RTM msg with nested attributes ?

With separate RTM msgtype for each syncE attribute we will end up 
bloating the RTM msg namespace.

(these api's could also be in ethtool given its directly querying the 
drivers)


>   include/linux/netdevice.h      |   9 ++
>   include/uapi/linux/if_link.h   |  26 +++++
>   include/uapi/linux/rtnetlink.h |   7 ++
>   net/core/rtnetlink.c           | 174 +++++++++++++++++++++++++++++++++
>   security/selinux/nlmsgtab.c    |   3 +
>   5 files changed, 219 insertions(+)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index ef2b381dae0c..708bd8336155 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1576,6 +1576,15 @@ struct net_device_ops {
>   	int			(*ndo_get_eec_src)(struct net_device *dev,
>   						   u32 *src,
>   						   struct netlink_ext_ack *extack);
> +	int			(*ndo_get_rclk_range)(struct net_device *dev,
> +						      u32 *min_idx, u32 *max_idx,
> +						      struct netlink_ext_ack *extack);
> +	int			(*ndo_set_rclk_out)(struct net_device *dev,
> +						    u32 out_idx, bool ena,
> +						    struct netlink_ext_ack *extack);
> +	int			(*ndo_get_rclk_state)(struct net_device *dev,
> +						      u32 out_idx, bool *ena,
> +						      struct netlink_ext_ack *extack);
>   };
>   
>   /**
> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
> index 8eae80f287e9..e27c153cfba3 100644
> --- a/include/uapi/linux/if_link.h
> +++ b/include/uapi/linux/if_link.h
> @@ -1304,4 +1304,30 @@ enum {
>   
>   #define IFLA_EEC_MAX (__IFLA_EEC_MAX - 1)
>   
> +struct if_rclk_range_msg {
> +	__u32 ifindex;
> +};
> +
> +enum {
> +	IFLA_RCLK_RANGE_UNSPEC,
> +	IFLA_RCLK_RANGE_MIN_PIN,
> +	IFLA_RCLK_RANGE_MAX_PIN,
> +	__IFLA_RCLK_RANGE_MAX,
> +};
> +
> +struct if_set_rclk_msg {
> +	__u32 ifindex;
> +	__u32 out_idx;
> +	__u32 flags;
> +};
> +
> +#define SET_RCLK_FLAGS_ENA	(1U << 0)
> +
> +enum {
> +	IFLA_RCLK_STATE_UNSPEC,
> +	IFLA_RCLK_STATE_OUT_IDX,
> +	IFLA_RCLK_STATE_COUNT,
> +	__IFLA_RCLK_STATE_MAX,
> +};
> +
>   #endif /* _UAPI_LINUX_IF_LINK_H */
> diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
> index 1d8662afd6bd..6c0d96d56ec7 100644
> --- a/include/uapi/linux/rtnetlink.h
> +++ b/include/uapi/linux/rtnetlink.h
> @@ -185,6 +185,13 @@ enum {
>   	RTM_GETNEXTHOPBUCKET,
>   #define RTM_GETNEXTHOPBUCKET	RTM_GETNEXTHOPBUCKET
>   
> +	RTM_GETRCLKRANGE = 120,
> +#define RTM_GETRCLKRANGE	RTM_GETRCLKRANGE
> +	RTM_GETRCLKSTATE = 121,
> +#define RTM_GETRCLKSTATE	RTM_GETRCLKSTATE
> +	RTM_SETRCLKSTATE = 122,
> +#define RTM_SETRCLKSTATE	RTM_SETRCLKSTATE
> +
>   	RTM_GETEECSTATE = 124,
>   #define RTM_GETEECSTATE	RTM_GETEECSTATE
>   
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 03bc773d0e69..bc1e050f6d38 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -5544,6 +5544,176 @@ static int rtnl_eec_state_get(struct sk_buff *skb, struct nlmsghdr *nlh,
>   	return err;
>   }
>   
> +static int rtnl_fill_rclk_range(struct sk_buff *skb, struct net_device *dev,
> +				u32 portid, u32 seq,
> +				struct netlink_callback *cb, int flags,
> +				struct netlink_ext_ack *extack)
> +{
> +	const struct net_device_ops *ops = dev->netdev_ops;
> +	struct if_rclk_range_msg *state_msg;
> +	struct nlmsghdr *nlh;
> +	u32 min_idx, max_idx;
> +	int err;
> +
> +	ASSERT_RTNL();
> +
> +	if (!ops->ndo_get_rclk_range)
> +		return -EOPNOTSUPP;
> +
> +	err = ops->ndo_get_rclk_range(dev, &min_idx, &max_idx, extack);
> +	if (err)
> +		return err;
> +
> +	nlh = nlmsg_put(skb, portid, seq, RTM_GETRCLKRANGE, sizeof(*state_msg),
> +			flags);
> +	if (!nlh)
> +		return -EMSGSIZE;
> +
> +	state_msg = nlmsg_data(nlh);
> +	state_msg->ifindex = dev->ifindex;
> +
> +	if (nla_put_u32(skb, IFLA_RCLK_RANGE_MIN_PIN, min_idx) ||
> +	    nla_put_u32(skb, IFLA_RCLK_RANGE_MAX_PIN, max_idx))
> +		return -EMSGSIZE;
> +
> +	nlmsg_end(skb, nlh);
> +	return 0;
> +}
> +
> +static int rtnl_rclk_range_get(struct sk_buff *skb, struct nlmsghdr *nlh,
> +			       struct netlink_ext_ack *extack)
> +{
> +	struct net *net = sock_net(skb->sk);
> +	struct if_eec_state_msg *state;
> +	struct net_device *dev;
> +	struct sk_buff *nskb;
> +	int err;
> +
> +	state = nlmsg_data(nlh);
> +	dev = __dev_get_by_index(net, state->ifindex);
> +	if (!dev) {
> +		NL_SET_ERR_MSG(extack, "unknown ifindex");
> +		return -ENODEV;
> +	}
> +
> +	nskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> +	if (!nskb)
> +		return -ENOBUFS;
> +
> +	err = rtnl_fill_rclk_range(nskb, dev, NETLINK_CB(skb).portid,
> +				   nlh->nlmsg_seq, NULL, nlh->nlmsg_flags,
> +				   extack);
> +	if (err < 0)
> +		kfree_skb(nskb);
> +	else
> +		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid);
> +
> +	return err;
> +}
> +
> +static int rtnl_fill_rclk_state(struct sk_buff *skb, struct net_device *dev,
> +				u32 portid, u32 seq,
> +				struct netlink_callback *cb, int flags,
> +				struct netlink_ext_ack *extack)
> +{
> +	const struct net_device_ops *ops = dev->netdev_ops;
> +	u32 min_idx, max_idx, src_idx, count = 0;
> +	struct if_eec_state_msg *state_msg;
> +	struct nlmsghdr *nlh;
> +	bool ena;
> +	int err;
> +
> +	ASSERT_RTNL();
> +
> +	if (!ops->ndo_get_rclk_state || !ops->ndo_get_rclk_range)
> +		return -EOPNOTSUPP;
> +
> +	err = ops->ndo_get_rclk_range(dev, &min_idx, &max_idx, extack);
> +	if (err)
> +		return err;
> +
> +	nlh = nlmsg_put(skb, portid, seq, RTM_GETRCLKSTATE, sizeof(*state_msg),
> +			flags);
> +	if (!nlh)
> +		return -EMSGSIZE;
> +
> +	state_msg = nlmsg_data(nlh);
> +	state_msg->ifindex = dev->ifindex;
> +
> +	for (src_idx = min_idx; src_idx <= max_idx; src_idx++) {
> +		ops->ndo_get_rclk_state(dev, src_idx, &ena, extack);
> +		if (!ena)
> +			continue;
> +
> +		if (nla_put_u32(skb, IFLA_RCLK_STATE_OUT_IDX, src_idx))
> +			return -EMSGSIZE;
> +		count++;
> +	}
> +
> +	if (nla_put_u32(skb, IFLA_RCLK_STATE_COUNT, count))
> +		return -EMSGSIZE;
> +
> +	nlmsg_end(skb, nlh);
> +	return 0;
> +}
> +
> +static int rtnl_rclk_state_get(struct sk_buff *skb, struct nlmsghdr *nlh,
> +			       struct netlink_ext_ack *extack)
> +{
> +	struct net *net = sock_net(skb->sk);
> +	struct if_eec_state_msg *state;
> +	struct net_device *dev;
> +	struct sk_buff *nskb;
> +	int err;
> +
> +	state = nlmsg_data(nlh);
> +	dev = __dev_get_by_index(net, state->ifindex);
> +	if (!dev) {
> +		NL_SET_ERR_MSG(extack, "unknown ifindex");
> +		return -ENODEV;
> +	}
> +
> +	nskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> +	if (!nskb)
> +		return -ENOBUFS;
> +
> +	err = rtnl_fill_rclk_state(nskb, dev, NETLINK_CB(skb).portid,
> +				   nlh->nlmsg_seq, NULL, nlh->nlmsg_flags,
> +				   extack);
> +	if (err < 0)
> +		kfree_skb(nskb);
> +	else
> +		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid);
> +
> +	return err;
> +}
> +
> +static int rtnl_rclk_set(struct sk_buff *skb, struct nlmsghdr *nlh,
> +			 struct netlink_ext_ack *extack)
> +{
> +	struct net *net = sock_net(skb->sk);
> +	struct if_set_rclk_msg *state;
> +	struct net_device *dev;
> +	bool ena;
> +	int err;
> +
> +	state = nlmsg_data(nlh);
> +	dev = __dev_get_by_index(net, state->ifindex);
> +	if (!dev) {
> +		NL_SET_ERR_MSG(extack, "unknown ifindex");
> +		return -ENODEV;
> +	}
> +
> +	if (!dev->netdev_ops->ndo_set_rclk_out)
> +		return -EOPNOTSUPP;
> +
> +	ena = !!(state->flags & SET_RCLK_FLAGS_ENA);
> +	err = dev->netdev_ops->ndo_set_rclk_out(dev, state->out_idx, ena,
> +						extack);
> +
> +	return err;
> +}
> +
>   /* Process one rtnetlink message. */
>   
>   static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
> @@ -5770,5 +5940,9 @@ void __init rtnetlink_init(void)
>   	rtnl_register(PF_UNSPEC, RTM_GETSTATS, rtnl_stats_get, rtnl_stats_dump,
>   		      0);
>   
> +	rtnl_register(PF_UNSPEC, RTM_GETRCLKRANGE, rtnl_rclk_range_get, NULL, 0);
> +	rtnl_register(PF_UNSPEC, RTM_GETRCLKSTATE, rtnl_rclk_state_get, NULL, 0);
> +	rtnl_register(PF_UNSPEC, RTM_SETRCLKSTATE, rtnl_rclk_set, NULL, 0);
> +
>   	rtnl_register(PF_UNSPEC, RTM_GETEECSTATE, rtnl_eec_state_get, NULL, 0);
>   }
> diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
> index 2c66e722ea9c..57c7c85edd4d 100644
> --- a/security/selinux/nlmsgtab.c
> +++ b/security/selinux/nlmsgtab.c
> @@ -91,6 +91,9 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
>   	{ RTM_NEWNEXTHOPBUCKET,	NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>   	{ RTM_DELNEXTHOPBUCKET,	NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>   	{ RTM_GETNEXTHOPBUCKET,	NETLINK_ROUTE_SOCKET__NLMSG_READ  },
> +	{ RTM_GETRCLKRANGE,	NETLINK_ROUTE_SOCKET__NLMSG_READ  },
> +	{ RTM_GETRCLKSTATE,	NETLINK_ROUTE_SOCKET__NLMSG_READ  },
> +	{ RTM_SETRCLKSTATE,	NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>   	{ RTM_GETEECSTATE,	NETLINK_ROUTE_SOCKET__NLMSG_READ  },
>   };
>