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
rss_parse_request(struct ethnl_req_info * req_info,struct nlattr ** tb,struct netlink_ext_ack * extack)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
rss_prepare_get(const struct rss_req_info * request,struct net_device * dev,struct rss_reply_data * data,const struct genl_info * info)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 
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 	if (data->hkey_size)
86 		data->hkey = rss_config + indir_bytes;
87 
88 	rxfh.indir_size = data->indir_size;
89 	rxfh.indir = data->indir_table;
90 	rxfh.key_size = data->hkey_size;
91 	rxfh.key = data->hkey;
92 
93 	ret = ops->get_rxfh(dev, &rxfh);
94 	if (ret)
95 		goto out_ops;
96 
97 	data->hfunc = rxfh.hfunc;
98 	data->input_xfrm = rxfh.input_xfrm;
99 out_ops:
100 	ethnl_ops_complete(dev);
101 	return ret;
102 }
103 
104 static int
rss_prepare_ctx(const struct rss_req_info * request,struct net_device * dev,struct rss_reply_data * data,const struct genl_info * info)105 rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
106 		struct rss_reply_data *data, const struct genl_info *info)
107 {
108 	struct ethtool_rxfh_context *ctx;
109 	u32 total_size, indir_bytes;
110 	u8 *rss_config;
111 
112 	data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
113 
114 	ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
115 	if (!ctx)
116 		return -ENOENT;
117 
118 	data->indir_size = ctx->indir_size;
119 	data->hkey_size = ctx->key_size;
120 	data->hfunc = ctx->hfunc;
121 	data->input_xfrm = ctx->input_xfrm;
122 
123 	indir_bytes = data->indir_size * sizeof(u32);
124 	total_size = indir_bytes + data->hkey_size;
125 	rss_config = kzalloc(total_size, GFP_KERNEL);
126 	if (!rss_config)
127 		return -ENOMEM;
128 
129 	data->indir_table = (u32 *)rss_config;
130 	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
131 
132 	if (data->hkey_size) {
133 		data->hkey = rss_config + indir_bytes;
134 		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
135 		       data->hkey_size);
136 	}
137 
138 	return 0;
139 }
140 
141 static int
rss_prepare_data(const struct ethnl_req_info * req_base,struct ethnl_reply_data * reply_base,const struct genl_info * info)142 rss_prepare_data(const struct ethnl_req_info *req_base,
143 		 struct ethnl_reply_data *reply_base,
144 		 const struct genl_info *info)
145 {
146 	struct rss_reply_data *data = RSS_REPDATA(reply_base);
147 	struct rss_req_info *request = RSS_REQINFO(req_base);
148 	struct net_device *dev = reply_base->dev;
149 	const struct ethtool_ops *ops;
150 
151 	ops = dev->ethtool_ops;
152 	if (!ops->get_rxfh)
153 		return -EOPNOTSUPP;
154 
155 	/* Some drivers don't handle rss_context */
156 	if (request->rss_context) {
157 		if (!ops->cap_rss_ctx_supported && !ops->create_rxfh_context)
158 			return -EOPNOTSUPP;
159 
160 		return rss_prepare_ctx(request, dev, data, info);
161 	}
162 
163 	return rss_prepare_get(request, dev, data, info);
164 }
165 
166 static int
rss_reply_size(const struct ethnl_req_info * req_base,const struct ethnl_reply_data * reply_base)167 rss_reply_size(const struct ethnl_req_info *req_base,
168 	       const struct ethnl_reply_data *reply_base)
169 {
170 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
171 	int len;
172 
173 	len = nla_total_size(sizeof(u32)) +	/* _RSS_CONTEXT */
174 	      nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
175 	      nla_total_size(sizeof(u32)) +	/* _RSS_INPUT_XFRM */
176 	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
177 	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
178 
179 	return len;
180 }
181 
182 static int
rss_fill_reply(struct sk_buff * skb,const struct ethnl_req_info * req_base,const struct ethnl_reply_data * reply_base)183 rss_fill_reply(struct sk_buff *skb, 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 	struct rss_req_info *request = RSS_REQINFO(req_base);
188 
189 	if (request->rss_context &&
190 	    nla_put_u32(skb, ETHTOOL_A_RSS_CONTEXT, request->rss_context))
191 		return -EMSGSIZE;
192 
193 	if ((data->indir_size &&
194 	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
195 		     sizeof(u32) * data->indir_size, data->indir_table)))
196 		return -EMSGSIZE;
197 
198 	if (data->no_key_fields)
199 		return 0;
200 
201 	if ((data->hfunc &&
202 	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
203 	    (data->input_xfrm &&
204 	     nla_put_u32(skb, ETHTOOL_A_RSS_INPUT_XFRM, data->input_xfrm)) ||
205 	    (data->hkey_size &&
206 	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
207 		return -EMSGSIZE;
208 
209 	return 0;
210 }
211 
rss_cleanup_data(struct ethnl_reply_data * reply_base)212 static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
213 {
214 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
215 
216 	kfree(data->indir_table);
217 }
218 
219 struct rss_nl_dump_ctx {
220 	unsigned long		ifindex;
221 	unsigned long		ctx_idx;
222 
223 	/* User wants to only dump contexts from given ifindex */
224 	unsigned int		match_ifindex;
225 	unsigned int		start_ctx;
226 };
227 
rss_dump_ctx(struct netlink_callback * cb)228 static struct rss_nl_dump_ctx *rss_dump_ctx(struct netlink_callback *cb)
229 {
230 	NL_ASSERT_CTX_FITS(struct rss_nl_dump_ctx);
231 
232 	return (struct rss_nl_dump_ctx *)cb->ctx;
233 }
234 
ethnl_rss_dump_start(struct netlink_callback * cb)235 int ethnl_rss_dump_start(struct netlink_callback *cb)
236 {
237 	const struct genl_info *info = genl_info_dump(cb);
238 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
239 	struct ethnl_req_info req_info = {};
240 	struct nlattr **tb = info->attrs;
241 	int ret;
242 
243 	/* Filtering by context not supported */
244 	if (tb[ETHTOOL_A_RSS_CONTEXT]) {
245 		NL_SET_BAD_ATTR(info->extack, tb[ETHTOOL_A_RSS_CONTEXT]);
246 		return -EINVAL;
247 	}
248 	if (tb[ETHTOOL_A_RSS_START_CONTEXT]) {
249 		ctx->start_ctx = nla_get_u32(tb[ETHTOOL_A_RSS_START_CONTEXT]);
250 		ctx->ctx_idx = ctx->start_ctx;
251 	}
252 
253 	ret = ethnl_parse_header_dev_get(&req_info,
254 					 tb[ETHTOOL_A_RSS_HEADER],
255 					 sock_net(cb->skb->sk), cb->extack,
256 					 false);
257 	if (req_info.dev) {
258 		ctx->match_ifindex = req_info.dev->ifindex;
259 		ctx->ifindex = ctx->match_ifindex;
260 		ethnl_parse_header_dev_put(&req_info);
261 		req_info.dev = NULL;
262 	}
263 
264 	return ret;
265 }
266 
267 static int
rss_dump_one_ctx(struct sk_buff * skb,struct netlink_callback * cb,struct net_device * dev,u32 rss_context)268 rss_dump_one_ctx(struct sk_buff *skb, struct netlink_callback *cb,
269 		 struct net_device *dev, u32 rss_context)
270 {
271 	const struct genl_info *info = genl_info_dump(cb);
272 	struct rss_reply_data data = {};
273 	struct rss_req_info req = {};
274 	void *ehdr;
275 	int ret;
276 
277 	req.rss_context = rss_context;
278 
279 	ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_RSS_GET_REPLY);
280 	if (!ehdr)
281 		return -EMSGSIZE;
282 
283 	ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_RSS_HEADER);
284 	if (ret < 0)
285 		goto err_cancel;
286 
287 	/* Context 0 is not currently storred or cached in the XArray */
288 	if (!rss_context)
289 		ret = rss_prepare_get(&req, dev, &data, info);
290 	else
291 		ret = rss_prepare_ctx(&req, dev, &data, info);
292 	if (ret)
293 		goto err_cancel;
294 
295 	ret = rss_fill_reply(skb, &req.base, &data.base);
296 	if (ret)
297 		goto err_cleanup;
298 	genlmsg_end(skb, ehdr);
299 
300 	rss_cleanup_data(&data.base);
301 	return 0;
302 
303 err_cleanup:
304 	rss_cleanup_data(&data.base);
305 err_cancel:
306 	genlmsg_cancel(skb, ehdr);
307 	return ret;
308 }
309 
310 static int
rss_dump_one_dev(struct sk_buff * skb,struct netlink_callback * cb,struct net_device * dev)311 rss_dump_one_dev(struct sk_buff *skb, struct netlink_callback *cb,
312 		 struct net_device *dev)
313 {
314 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
315 	int ret;
316 
317 	if (!dev->ethtool_ops->get_rxfh)
318 		return 0;
319 
320 	if (!ctx->ctx_idx) {
321 		ret = rss_dump_one_ctx(skb, cb, dev, 0);
322 		if (ret)
323 			return ret;
324 		ctx->ctx_idx++;
325 	}
326 
327 	for (; xa_find(&dev->ethtool->rss_ctx, &ctx->ctx_idx,
328 		       ULONG_MAX, XA_PRESENT); ctx->ctx_idx++) {
329 		ret = rss_dump_one_ctx(skb, cb, dev, ctx->ctx_idx);
330 		if (ret)
331 			return ret;
332 	}
333 	ctx->ctx_idx = ctx->start_ctx;
334 
335 	return 0;
336 }
337 
ethnl_rss_dumpit(struct sk_buff * skb,struct netlink_callback * cb)338 int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
339 {
340 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
341 	struct net *net = sock_net(skb->sk);
342 	struct net_device *dev;
343 	int ret = 0;
344 
345 	rtnl_lock();
346 	for_each_netdev_dump(net, dev, ctx->ifindex) {
347 		if (ctx->match_ifindex && ctx->match_ifindex != ctx->ifindex)
348 			break;
349 
350 		netdev_lock_ops(dev);
351 		ret = rss_dump_one_dev(skb, cb, dev);
352 		netdev_unlock_ops(dev);
353 		if (ret)
354 			break;
355 	}
356 	rtnl_unlock();
357 
358 	return ret;
359 }
360 
361 const struct ethnl_request_ops ethnl_rss_request_ops = {
362 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
363 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
364 	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
365 	.req_info_size		= sizeof(struct rss_req_info),
366 	.reply_data_size	= sizeof(struct rss_reply_data),
367 
368 	.parse_request		= rss_parse_request,
369 	.prepare_data		= rss_prepare_data,
370 	.reply_size		= rss_reply_size,
371 	.fill_reply		= rss_fill_reply,
372 	.cleanup_data		= rss_cleanup_data,
373 };
374