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				input_xfrm;
17	u32				*indir_table;
18	u8				*hkey;
19};
20
21#define RSS_REQINFO(__req_base) \
22	container_of(__req_base, struct rss_req_info, base)
23
24#define RSS_REPDATA(__reply_base) \
25	container_of(__reply_base, struct rss_reply_data, base)
26
27const struct nla_policy ethnl_rss_get_policy[] = {
28	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
29	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
30};
31
32static int
33rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
34		  struct netlink_ext_ack *extack)
35{
36	struct rss_req_info *request = RSS_REQINFO(req_info);
37
38	if (tb[ETHTOOL_A_RSS_CONTEXT])
39		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
40
41	return 0;
42}
43
44static int
45rss_prepare_data(const struct ethnl_req_info *req_base,
46		 struct ethnl_reply_data *reply_base,
47		 const struct genl_info *info)
48{
49	struct rss_reply_data *data = RSS_REPDATA(reply_base);
50	struct rss_req_info *request = RSS_REQINFO(req_base);
51	struct net_device *dev = reply_base->dev;
52	struct ethtool_rxfh_param rxfh = {};
53	const struct ethtool_ops *ops;
54	u32 total_size, indir_bytes;
55	u8 *rss_config;
56	int ret;
57
58	ops = dev->ethtool_ops;
59	if (!ops->get_rxfh)
60		return -EOPNOTSUPP;
61
62	/* Some drivers don't handle rss_context */
63	if (request->rss_context && !ops->cap_rss_ctx_supported)
64		return -EOPNOTSUPP;
65
66	ret = ethnl_ops_begin(dev);
67	if (ret < 0)
68		return ret;
69
70	data->indir_size = 0;
71	data->hkey_size = 0;
72	if (ops->get_rxfh_indir_size)
73		data->indir_size = ops->get_rxfh_indir_size(dev);
74	if (ops->get_rxfh_key_size)
75		data->hkey_size = ops->get_rxfh_key_size(dev);
76
77	indir_bytes = data->indir_size * sizeof(u32);
78	total_size = indir_bytes + data->hkey_size;
79	rss_config = kzalloc(total_size, GFP_KERNEL);
80	if (!rss_config) {
81		ret = -ENOMEM;
82		goto out_ops;
83	}
84
85	if (data->indir_size)
86		data->indir_table = (u32 *)rss_config;
87	if (data->hkey_size)
88		data->hkey = rss_config + indir_bytes;
89
90	rxfh.indir_size = data->indir_size;
91	rxfh.indir = data->indir_table;
92	rxfh.key_size = data->hkey_size;
93	rxfh.key = data->hkey;
94	rxfh.rss_context = request->rss_context;
95
96	ret = ops->get_rxfh(dev, &rxfh);
97	if (ret)
98		goto out_ops;
99
100	data->hfunc = rxfh.hfunc;
101	data->input_xfrm = rxfh.input_xfrm;
102out_ops:
103	ethnl_ops_complete(dev);
104	return ret;
105}
106
107static int
108rss_reply_size(const struct ethnl_req_info *req_base,
109	       const struct ethnl_reply_data *reply_base)
110{
111	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
112	int len;
113
114	len = nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
115	      nla_total_size(sizeof(u32)) +	/* _RSS_INPUT_XFRM */
116	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
117	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
118
119	return len;
120}
121
122static int
123rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
124	       const struct ethnl_reply_data *reply_base)
125{
126	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
127
128	if ((data->hfunc &&
129	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
130	    (data->input_xfrm &&
131	     nla_put_u32(skb, ETHTOOL_A_RSS_INPUT_XFRM, data->input_xfrm)) ||
132	    (data->indir_size &&
133	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
134		     sizeof(u32) * data->indir_size, data->indir_table)) ||
135	    (data->hkey_size &&
136	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
137		return -EMSGSIZE;
138
139	return 0;
140}
141
142static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
143{
144	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
145
146	kfree(data->indir_table);
147}
148
149const struct ethnl_request_ops ethnl_rss_request_ops = {
150	.request_cmd		= ETHTOOL_MSG_RSS_GET,
151	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
152	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
153	.req_info_size		= sizeof(struct rss_req_info),
154	.reply_data_size	= sizeof(struct rss_reply_data),
155
156	.parse_request		= rss_parse_request,
157	.prepare_data		= rss_prepare_data,
158	.reply_size		= rss_reply_size,
159	.fill_reply		= rss_fill_reply,
160	.cleanup_data		= rss_cleanup_data,
161};
162