1// SPDX-License-Identifier: GPL-2.0-only
  2
  3#include "netlink.h"
  4#include "common.h"
  5
  6struct rss_req_info {
  7	struct ethnl_req_info		base;
  8	u32				rss_context;
  9};
 10
 11struct rss_reply_data {
 12	struct ethnl_reply_data		base;
 13	u32				indir_size;
 14	u32				hkey_size;
 15	u32				hfunc;
 16	u32				*indir_table;
 17	u8				*hkey;
 18};
 19
 20#define RSS_REQINFO(__req_base) \
 21	container_of(__req_base, struct rss_req_info, base)
 22
 23#define RSS_REPDATA(__reply_base) \
 24	container_of(__reply_base, struct rss_reply_data, base)
 25
 26const struct nla_policy ethnl_rss_get_policy[] = {
 27	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
 28	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
 29};
 30
 31static int
 32rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
 33		  struct netlink_ext_ack *extack)
 34{
 35	struct rss_req_info *request = RSS_REQINFO(req_info);
 36
 37	if (tb[ETHTOOL_A_RSS_CONTEXT])
 38		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
 39
 40	return 0;
 41}
 42
 43static int
 44rss_prepare_data(const struct ethnl_req_info *req_base,
 45		 struct ethnl_reply_data *reply_base, struct genl_info *info)
 46{
 47	struct rss_reply_data *data = RSS_REPDATA(reply_base);
 48	struct rss_req_info *request = RSS_REQINFO(req_base);
 49	struct net_device *dev = reply_base->dev;
 50	const struct ethtool_ops *ops;
 51	u32 total_size, indir_bytes;
 52	u8 dev_hfunc = 0;
 53	u8 *rss_config;
 54	int ret;
 55
 56	ops = dev->ethtool_ops;
 57	if (!ops->get_rxfh)
 58		return -EOPNOTSUPP;
 59
 60	/* Some drivers don't handle rss_context */
 61	if (request->rss_context && !ops->get_rxfh_context)
 62		return -EOPNOTSUPP;
 63
 64	ret = ethnl_ops_begin(dev);
 65	if (ret < 0)
 66		return ret;
 67
 68	data->indir_size = 0;
 69	data->hkey_size = 0;
 70	if (ops->get_rxfh_indir_size)
 71		data->indir_size = ops->get_rxfh_indir_size(dev);
 72	if (ops->get_rxfh_key_size)
 73		data->hkey_size = ops->get_rxfh_key_size(dev);
 74
 75	indir_bytes = data->indir_size * sizeof(u32);
 76	total_size = indir_bytes + data->hkey_size;
 77	rss_config = kzalloc(total_size, GFP_KERNEL);
 78	if (!rss_config) {
 79		ret = -ENOMEM;
 80		goto out_ops;
 81	}
 82
 83	if (data->indir_size)
 84		data->indir_table = (u32 *)rss_config;
 85
 86	if (data->hkey_size)
 87		data->hkey = rss_config + indir_bytes;
 88
 89	if (request->rss_context)
 90		ret = ops->get_rxfh_context(dev, data->indir_table, data->hkey,
 91					    &dev_hfunc, request->rss_context);
 92	else
 93		ret = ops->get_rxfh(dev, data->indir_table, data->hkey,
 94				    &dev_hfunc);
 95
 96	if (ret)
 97		goto out_ops;
 98
 99	data->hfunc = dev_hfunc;
100out_ops:
101	ethnl_ops_complete(dev);
102	return ret;
103}
104
105static int
106rss_reply_size(const struct ethnl_req_info *req_base,
107	       const struct ethnl_reply_data *reply_base)
108{
109	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
110	int len;
111
112	len = nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
113	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
114	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
115
116	return len;
117}
118
119static int
120rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
121	       const struct ethnl_reply_data *reply_base)
122{
123	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
124
125	if ((data->hfunc &&
126	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
127	    (data->indir_size &&
128	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
129		     sizeof(u32) * data->indir_size, data->indir_table)) ||
130	    (data->hkey_size &&
131	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
132		return -EMSGSIZE;
133
134	return 0;
135}
136
137static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
138{
139	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
140
141	kfree(data->indir_table);
142}
143
144const struct ethnl_request_ops ethnl_rss_request_ops = {
145	.request_cmd		= ETHTOOL_MSG_RSS_GET,
146	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
147	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
148	.req_info_size		= sizeof(struct rss_req_info),
149	.reply_data_size	= sizeof(struct rss_reply_data),
150
151	.parse_request		= rss_parse_request,
152	.prepare_data		= rss_prepare_data,
153	.reply_size		= rss_reply_size,
154	.fill_reply		= rss_fill_reply,
155	.cleanup_data		= rss_cleanup_data,
156};