Commit 99132b6e authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

ethtool: netlink: handle SET intro/outro in the common code 



Most ethtool SET callbacks follow the same general structure.

  ethnl_parse_header_dev_get()
  rtnl_lock()
  ethnl_ops_begin()

  ... do stuff ...

  ethtool_notify()
  ethnl_ops_complete()
  rtnl_unlock()
  ethnl_parse_header_dev_put()

This leads to a lot of copy / pasted code an bugs when people
mis-handle the error path.

Add a generic implementation of this pattern with a .set callback
in struct ethnl_request_ops called to "do stuff".

Also add an optional .set_validate which is called before
ethnl_ops_begin() -- a lot of implementations do basic request
capability / sanity checking at that point.

Because we want to avoid generating the notification when
no change happened - adopt a slightly hairy return values:
 - 0 means nothing to do (no notification)
 - 1 means done / continue
 - negative error codes on error

Reuse .hdr_attr from struct ethnl_request_ops, GET and SET
use the same attr spaces in all cases.

Convert pause as an example (and to avoid unused function warnings).

Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c766e077

net/ethtool/netlink.c

+48 −1
Original line number Diff line number Diff line
@@ -279,6 +279,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = { 
	[ETHTOOL_MSG_CHANNELS_GET]	= &ethnl_channels_request_ops,

	[ETHTOOL_MSG_COALESCE_GET]	= &ethnl_coalesce_request_ops,

	[ETHTOOL_MSG_PAUSE_GET]		= &ethnl_pause_request_ops,

	[ETHTOOL_MSG_PAUSE_SET]		= &ethnl_pause_request_ops,

	[ETHTOOL_MSG_EEE_GET]		= &ethnl_eee_request_ops,

	[ETHTOOL_MSG_FEC_GET]		= &ethnl_fec_request_ops,

	[ETHTOOL_MSG_TSINFO_GET]	= &ethnl_tsinfo_request_ops,
@@ -591,6 +592,52 @@ static int ethnl_default_done(struct netlink_callback *cb) 
	return 0;

}



static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)

{

	const struct ethnl_request_ops *ops;

	struct ethnl_req_info req_info = {};

	const u8 cmd = info->genlhdr->cmd;

	int ret;



	ops = ethnl_default_requests[cmd];

	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", cmd))

		return -EOPNOTSUPP;

	if (GENL_REQ_ATTR_CHECK(info, ops->hdr_attr))

		return -EINVAL;



	ret = ethnl_parse_header_dev_get(&req_info, info->attrs[ops->hdr_attr],

					 genl_info_net(info), info->extack,

					 true);

	if (ret < 0)

		return ret;



	if (ops->set_validate) {

		ret = ops->set_validate(&req_info, info);

		/* 0 means nothing to do */

		if (ret <= 0)

			goto out_dev;

	}



	rtnl_lock();

	ret = ethnl_ops_begin(req_info.dev);

	if (ret < 0)

		goto out_rtnl;



	ret = ops->set(&req_info, info);

	if (ret <= 0)

		goto out_ops;

	ethtool_notify(req_info.dev, ops->set_ntf_cmd, NULL);



	ret = 0;

out_ops:

	ethnl_ops_complete(req_info.dev);

out_rtnl:

	rtnl_unlock();

out_dev:

	ethnl_parse_header_dev_put(&req_info);

	return ret;

}



static const struct ethnl_request_ops *

ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {

	[ETHTOOL_MSG_LINKINFO_NTF]	= &ethnl_linkinfo_request_ops,
@@ -921,7 +968,7 @@ static const struct genl_ops ethtool_genl_ops[] = { 
	{

		.cmd	= ETHTOOL_MSG_PAUSE_SET,

		.flags	= GENL_UNS_ADMIN_PERM,

		.doit	= ethnl_set_pause,

		.doit	= ethnl_default_set_doit,

		.policy = ethnl_pause_set_policy,

		.maxattr = ARRAY_SIZE(ethnl_pause_set_policy) - 1,

	},

net/ethtool/netlink.h

+20 −2
Original line number Diff line number Diff line
@@ -284,13 +284,14 @@ int ethnl_ops_begin(struct net_device *dev); 
void ethnl_ops_complete(struct net_device *dev);



/**

 * struct ethnl_request_ops - unified handling of GET requests

 * struct ethnl_request_ops - unified handling of GET and SET requests

 * @request_cmd:      command id for request (GET)

 * @reply_cmd:        command id for reply (GET_REPLY)

 * @hdr_attr:         attribute type for request header

 * @req_info_size:    size of request info

 * @reply_data_size:  size of reply data

 * @allow_nodev_do:   allow non-dump request with no device identification

 * @set_ntf_cmd:      notification to generate on changes (SET)

 * @parse_request:

 *	Parse request except common header (struct ethnl_req_info). Common

 *	header is already filled on entry, the rest up to @repdata_offset
@@ -319,6 +320,18 @@ void ethnl_ops_complete(struct net_device *dev); 
 *	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.

 * @set_validate:

 *	Check if set operation is supported for a given device, and perform

 *	extra input checks. Expected return values:

 *	 - 0 if the operation is a noop for the device (rare)

 *	 - 1 if operation should proceed to calling @set

 *	 - negative errno on errors

 *	Called without any locks, just a reference on the netdev.

 * @set:

 *	Execute the set operation. The implementation should return

 *	 - 0 if no configuration has changed

 *	 - 1 if configuration changed and notification should be generated

 *	 - negative errno on errors

 *

 * Description of variable parts of GET request handling when using the

 * unified infrastructure. When used, a pointer to an instance of this
@@ -335,6 +348,7 @@ struct ethnl_request_ops { 
	unsigned int		req_info_size;

	unsigned int		reply_data_size;

	bool			allow_nodev_do;

	u8			set_ntf_cmd;



	int (*parse_request)(struct ethnl_req_info *req_info,

			     struct nlattr **tb,
@@ -348,6 +362,11 @@ struct ethnl_request_ops { 
			  const struct ethnl_req_info *req_info,

			  const struct ethnl_reply_data *reply_data);

	void (*cleanup_data)(struct ethnl_reply_data *reply_data);



	int (*set_validate)(struct ethnl_req_info *req_info,

			    struct genl_info *info);

	int (*set)(struct ethnl_req_info *req_info,

		   struct genl_info *info);

};



/* request handlers */
@@ -432,7 +451,6 @@ int ethnl_set_privflags(struct sk_buff *skb, struct genl_info *info); 
int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info);

int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info);

int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info);

int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info);

int ethnl_set_eee(struct sk_buff *skb, struct genl_info *info);

int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);

int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info);

net/ethtool/pause.c

+32 −47
Original line number Diff line number Diff line
@@ -161,19 +161,6 @@ static int pause_fill_reply(struct sk_buff *skb, 
	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,

	.req_info_size		= sizeof(struct pause_req_info),

	.reply_data_size	= sizeof(struct pause_reply_data),



	.parse_request		= pause_parse_request,

	.prepare_data		= pause_prepare_data,

	.reply_size		= pause_reply_size,

	.fill_reply		= pause_fill_reply,

};



/* PAUSE_SET */



const struct nla_policy ethnl_pause_set_policy[] = {
@@ -184,51 +171,49 @@ const struct nla_policy ethnl_pause_set_policy[] = { 
	[ETHTOOL_A_PAUSE_TX]			= { .type = NLA_U8 },

};



int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info)

static int

ethnl_set_pause_validate(struct ethnl_req_info *req_info,

			 struct genl_info *info)

{

	const struct ethtool_ops *ops = req_info->dev->ethtool_ops;



	return ops->get_pauseparam && ops->set_pauseparam ? 1 : -EOPNOTSUPP;

}



static int

ethnl_set_pause(struct ethnl_req_info *req_info, struct genl_info *info)

{

	struct net_device *dev = req_info->dev;

	struct ethtool_pauseparam params = {};

	struct ethnl_req_info req_info = {};

	struct nlattr **tb = info->attrs;

	const struct ethtool_ops *ops;

	struct net_device *dev;

	bool mod = false;

	int ret;



	ret = ethnl_parse_header_dev_get(&req_info,

					 tb[ETHTOOL_A_PAUSE_HEADER],

					 genl_info_net(info), info->extack,

					 true);

	if (ret < 0)

		return ret;

	dev = req_info.dev;

	ops = dev->ethtool_ops;

	ret = -EOPNOTSUPP;

	if (!ops->get_pauseparam || !ops->set_pauseparam)

		goto out_dev;



	rtnl_lock();

	ret = ethnl_ops_begin(dev);

	if (ret < 0)

		goto out_rtnl;

	ops->get_pauseparam(dev, &params);

	dev->ethtool_ops->get_pauseparam(dev, &params);



	ethnl_update_bool32(&params.autoneg, tb[ETHTOOL_A_PAUSE_AUTONEG], &mod);

	ethnl_update_bool32(&params.rx_pause, tb[ETHTOOL_A_PAUSE_RX], &mod);

	ethnl_update_bool32(&params.tx_pause, tb[ETHTOOL_A_PAUSE_TX], &mod);

	ret = 0;

	if (!mod)

		goto out_ops;

		return 0;



	ret = dev->ethtool_ops->set_pauseparam(dev, &params);

	if (ret < 0)

		goto out_ops;

	ethtool_notify(dev, ETHTOOL_MSG_PAUSE_NTF, NULL);



out_ops:

	ethnl_ops_complete(dev);

out_rtnl:

	rtnl_unlock();

out_dev:

	ethnl_parse_header_dev_put(&req_info);

	return ret;

	return ret < 0 ? ret : 1;

}



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,

	.req_info_size		= sizeof(struct pause_req_info),

	.reply_data_size	= sizeof(struct pause_reply_data),



	.parse_request		= pause_parse_request,

	.prepare_data		= pause_prepare_data,

	.reply_size		= pause_reply_size,

	.fill_reply		= pause_fill_reply,



	.set_validate		= ethnl_set_pause_validate,

	.set			= ethnl_set_pause,

	.set_ntf_cmd		= ETHTOOL_MSG_PAUSE_NTF,

};