xref: /linux/net/ethtool/rss.c (revision f7c595c9d9f4cce9ec335f0d3c5d875bb547f9d5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <net/netdev_lock.h>
4 
5 #include "netlink.h"
6 #include "common.h"
7 
8 struct rss_req_info {
9 	struct ethnl_req_info		base;
10 	u32				rss_context;
11 };
12 
13 struct rss_reply_data {
14 	struct ethnl_reply_data		base;
15 	bool				no_key_fields;
16 	u32				indir_size;
17 	u32				hkey_size;
18 	u32				hfunc;
19 	u32				input_xfrm;
20 	u32				*indir_table;
21 	u8				*hkey;
22 };
23 
24 #define RSS_REQINFO(__req_base) \
25 	container_of(__req_base, struct rss_req_info, base)
26 
27 #define RSS_REPDATA(__reply_base) \
28 	container_of(__reply_base, struct rss_reply_data, base)
29 
30 const struct nla_policy ethnl_rss_get_policy[] = {
31 	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
32 	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
33 	[ETHTOOL_A_RSS_START_CONTEXT] = { .type = NLA_U32 },
34 };
35 
36 static int
37 rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
38 		  struct netlink_ext_ack *extack)
39 {
40 	struct rss_req_info *request = RSS_REQINFO(req_info);
41 
42 	if (tb[ETHTOOL_A_RSS_CONTEXT])
43 		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
44 	if (tb[ETHTOOL_A_RSS_START_CONTEXT]) {
45 		NL_SET_BAD_ATTR(extack, tb[ETHTOOL_A_RSS_START_CONTEXT]);
46 		return -EINVAL;
47 	}
48 
49 	return 0;
50 }
51 
52 static int
53 rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
54 		struct rss_reply_data *data, const struct genl_info *info)
55 {
56 	struct ethtool_rxfh_param rxfh = {};
57 	const struct ethtool_ops *ops;
58 	u32 total_size, indir_bytes;
59 	u8 *rss_config;
60 	int ret;
61 
62 	ops = dev->ethtool_ops;
63 
64 	ret = ethnl_ops_begin(dev);
65 	if (ret < 0)
66 		return ret;
67 	mutex_lock(&dev->ethtool->rss_lock);
68 
69 	data->indir_size = 0;
70 	data->hkey_size = 0;
71 	if (ops->get_rxfh_indir_size)
72 		data->indir_size = ops->get_rxfh_indir_size(dev);
73 	if (ops->get_rxfh_key_size)
74 		data->hkey_size = ops->get_rxfh_key_size(dev);
75 
76 	indir_bytes = data->indir_size * sizeof(u32);
77 	total_size = indir_bytes + data->hkey_size;
78 	rss_config = kzalloc(total_size, GFP_KERNEL);
79 	if (!rss_config) {
80 		ret = -ENOMEM;
81 		goto out_unlock;
82 	}
83 
84 	if (data->indir_size)
85 		data->indir_table = (u32 *)rss_config;
86 	if (data->hkey_size)
87 		data->hkey = rss_config + indir_bytes;
88 
89 	rxfh.indir_size = data->indir_size;
90 	rxfh.indir = data->indir_table;
91 	rxfh.key_size = data->hkey_size;
92 	rxfh.key = data->hkey;
93 
94 	ret = ops->get_rxfh(dev, &rxfh);
95 	if (ret)
96 		goto out_unlock;
97 
98 	data->hfunc = rxfh.hfunc;
99 	data->input_xfrm = rxfh.input_xfrm;
100 out_unlock:
101 	mutex_unlock(&dev->ethtool->rss_lock);
102 	ethnl_ops_complete(dev);
103 	return ret;
104 }
105 
106 static int
107 rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
108 		struct rss_reply_data *data, const struct genl_info *info)
109 {
110 	struct ethtool_rxfh_context *ctx;
111 	u32 total_size, indir_bytes;
112 	u8 *rss_config;
113 	int ret;
114 
115 	data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
116 
117 	mutex_lock(&dev->ethtool->rss_lock);
118 	ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
119 	if (!ctx) {
120 		ret = -ENOENT;
121 		goto out_unlock;
122 	}
123 
124 	data->indir_size = ctx->indir_size;
125 	data->hkey_size = ctx->key_size;
126 	data->hfunc = ctx->hfunc;
127 	data->input_xfrm = ctx->input_xfrm;
128 
129 	indir_bytes = data->indir_size * sizeof(u32);
130 	total_size = indir_bytes + data->hkey_size;
131 	rss_config = kzalloc(total_size, GFP_KERNEL);
132 	if (!rss_config) {
133 		ret = -ENOMEM;
134 		goto out_unlock;
135 	}
136 
137 	data->indir_table = (u32 *)rss_config;
138 	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
139 
140 	if (data->hkey_size) {
141 		data->hkey = rss_config + indir_bytes;
142 		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
143 		       data->hkey_size);
144 	}
145 
146 	ret = 0;
147 out_unlock:
148 	mutex_unlock(&dev->ethtool->rss_lock);
149 	return ret;
150 }
151 
152 static int
153 rss_prepare(const struct rss_req_info *request, struct net_device *dev,
154 	    struct rss_reply_data *data, const struct genl_info *info)
155 {
156 	if (request->rss_context)
157 		return rss_prepare_ctx(request, dev, data, info);
158 	return rss_prepare_get(request, dev, data, info);
159 }
160 
161 static int
162 rss_prepare_data(const struct ethnl_req_info *req_base,
163 		 struct ethnl_reply_data *reply_base,
164 		 const struct genl_info *info)
165 {
166 	struct rss_reply_data *data = RSS_REPDATA(reply_base);
167 	struct rss_req_info *request = RSS_REQINFO(req_base);
168 	struct net_device *dev = reply_base->dev;
169 	const struct ethtool_ops *ops;
170 
171 	ops = dev->ethtool_ops;
172 	if (!ops->get_rxfh)
173 		return -EOPNOTSUPP;
174 
175 	/* Some drivers don't handle rss_context */
176 	if (request->rss_context && !ops->create_rxfh_context)
177 		return -EOPNOTSUPP;
178 
179 	return rss_prepare(request, dev, data, info);
180 }
181 
182 static int
183 rss_reply_size(const struct ethnl_req_info *req_base,
184 	       const struct ethnl_reply_data *reply_base)
185 {
186 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
187 	int len;
188 
189 	len = nla_total_size(sizeof(u32)) +	/* _RSS_CONTEXT */
190 	      nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
191 	      nla_total_size(sizeof(u32)) +	/* _RSS_INPUT_XFRM */
192 	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
193 	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
194 
195 	return len;
196 }
197 
198 static int
199 rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
200 	       const struct ethnl_reply_data *reply_base)
201 {
202 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
203 	struct rss_req_info *request = RSS_REQINFO(req_base);
204 
205 	if (request->rss_context &&
206 	    nla_put_u32(skb, ETHTOOL_A_RSS_CONTEXT, request->rss_context))
207 		return -EMSGSIZE;
208 
209 	if ((data->indir_size &&
210 	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
211 		     sizeof(u32) * data->indir_size, data->indir_table)))
212 		return -EMSGSIZE;
213 
214 	if (data->no_key_fields)
215 		return 0;
216 
217 	if ((data->hfunc &&
218 	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
219 	    (data->input_xfrm &&
220 	     nla_put_u32(skb, ETHTOOL_A_RSS_INPUT_XFRM, data->input_xfrm)) ||
221 	    (data->hkey_size &&
222 	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
223 		return -EMSGSIZE;
224 
225 	return 0;
226 }
227 
228 static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
229 {
230 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
231 
232 	kfree(data->indir_table);
233 }
234 
235 struct rss_nl_dump_ctx {
236 	unsigned long		ifindex;
237 	unsigned long		ctx_idx;
238 
239 	/* User wants to only dump contexts from given ifindex */
240 	unsigned int		match_ifindex;
241 	unsigned int		start_ctx;
242 };
243 
244 static struct rss_nl_dump_ctx *rss_dump_ctx(struct netlink_callback *cb)
245 {
246 	NL_ASSERT_CTX_FITS(struct rss_nl_dump_ctx);
247 
248 	return (struct rss_nl_dump_ctx *)cb->ctx;
249 }
250 
251 int ethnl_rss_dump_start(struct netlink_callback *cb)
252 {
253 	const struct genl_info *info = genl_info_dump(cb);
254 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
255 	struct ethnl_req_info req_info = {};
256 	struct nlattr **tb = info->attrs;
257 	int ret;
258 
259 	/* Filtering by context not supported */
260 	if (tb[ETHTOOL_A_RSS_CONTEXT]) {
261 		NL_SET_BAD_ATTR(info->extack, tb[ETHTOOL_A_RSS_CONTEXT]);
262 		return -EINVAL;
263 	}
264 	if (tb[ETHTOOL_A_RSS_START_CONTEXT]) {
265 		ctx->start_ctx = nla_get_u32(tb[ETHTOOL_A_RSS_START_CONTEXT]);
266 		ctx->ctx_idx = ctx->start_ctx;
267 	}
268 
269 	ret = ethnl_parse_header_dev_get(&req_info,
270 					 tb[ETHTOOL_A_RSS_HEADER],
271 					 sock_net(cb->skb->sk), cb->extack,
272 					 false);
273 	if (req_info.dev) {
274 		ctx->match_ifindex = req_info.dev->ifindex;
275 		ctx->ifindex = ctx->match_ifindex;
276 		ethnl_parse_header_dev_put(&req_info);
277 		req_info.dev = NULL;
278 	}
279 
280 	return ret;
281 }
282 
283 static int
284 rss_dump_one_ctx(struct sk_buff *skb, struct netlink_callback *cb,
285 		 struct net_device *dev, u32 rss_context)
286 {
287 	const struct genl_info *info = genl_info_dump(cb);
288 	struct rss_reply_data data = {};
289 	struct rss_req_info req = {};
290 	void *ehdr;
291 	int ret;
292 
293 	req.rss_context = rss_context;
294 
295 	ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_RSS_GET_REPLY);
296 	if (!ehdr)
297 		return -EMSGSIZE;
298 
299 	ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_RSS_HEADER);
300 	if (ret < 0)
301 		goto err_cancel;
302 
303 	ret = rss_prepare(&req, dev, &data, info);
304 	if (ret)
305 		goto err_cancel;
306 
307 	ret = rss_fill_reply(skb, &req.base, &data.base);
308 	if (ret)
309 		goto err_cleanup;
310 	genlmsg_end(skb, ehdr);
311 
312 	rss_cleanup_data(&data.base);
313 	return 0;
314 
315 err_cleanup:
316 	rss_cleanup_data(&data.base);
317 err_cancel:
318 	genlmsg_cancel(skb, ehdr);
319 	return ret;
320 }
321 
322 static int
323 rss_dump_one_dev(struct sk_buff *skb, struct netlink_callback *cb,
324 		 struct net_device *dev)
325 {
326 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
327 	int ret;
328 
329 	if (!dev->ethtool_ops->get_rxfh)
330 		return 0;
331 
332 	if (!ctx->ctx_idx) {
333 		ret = rss_dump_one_ctx(skb, cb, dev, 0);
334 		if (ret)
335 			return ret;
336 		ctx->ctx_idx++;
337 	}
338 
339 	for (; xa_find(&dev->ethtool->rss_ctx, &ctx->ctx_idx,
340 		       ULONG_MAX, XA_PRESENT); ctx->ctx_idx++) {
341 		ret = rss_dump_one_ctx(skb, cb, dev, ctx->ctx_idx);
342 		if (ret)
343 			return ret;
344 	}
345 	ctx->ctx_idx = ctx->start_ctx;
346 
347 	return 0;
348 }
349 
350 int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
351 {
352 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
353 	struct net *net = sock_net(skb->sk);
354 	struct net_device *dev;
355 	int ret = 0;
356 
357 	rtnl_lock();
358 	for_each_netdev_dump(net, dev, ctx->ifindex) {
359 		if (ctx->match_ifindex && ctx->match_ifindex != ctx->ifindex)
360 			break;
361 
362 		netdev_lock_ops(dev);
363 		ret = rss_dump_one_dev(skb, cb, dev);
364 		netdev_unlock_ops(dev);
365 		if (ret)
366 			break;
367 	}
368 	rtnl_unlock();
369 
370 	return ret;
371 }
372 
373 /* RSS_NTF */
374 
375 void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
376 {
377 	struct rss_req_info req_info = {
378 		.rss_context = rss_context,
379 	};
380 
381 	ethnl_notify(dev, ETHTOOL_MSG_RSS_NTF, &req_info.base);
382 }
383 
384 const struct ethnl_request_ops ethnl_rss_request_ops = {
385 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
386 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
387 	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
388 	.req_info_size		= sizeof(struct rss_req_info),
389 	.reply_data_size	= sizeof(struct rss_reply_data),
390 
391 	.parse_request		= rss_parse_request,
392 	.prepare_data		= rss_prepare_data,
393 	.reply_size		= rss_reply_size,
394 	.fill_reply		= rss_fill_reply,
395 	.cleanup_data		= rss_cleanup_data,
396 };
397