xref: /linux/net/sched/act_skbedit.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2008, Intel Corporation.
4  *
5  * Author: Alexander Duyck <alexander.h.duyck@intel.com>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/skbuff.h>
12 #include <linux/rtnetlink.h>
13 #include <net/netlink.h>
14 #include <net/pkt_sched.h>
15 #include <net/ip.h>
16 #include <net/ipv6.h>
17 #include <net/dsfield.h>
18 #include <net/pkt_cls.h>
19 #include <net/tc_wrapper.h>
20 
21 #include <linux/tc_act/tc_skbedit.h>
22 #include <net/tc_act/tc_skbedit.h>
23 
24 static struct tc_action_ops act_skbedit_ops;
25 
tcf_skbedit_hash(struct tcf_skbedit_params * params,struct sk_buff * skb)26 static u16 tcf_skbedit_hash(struct tcf_skbedit_params *params,
27 			    struct sk_buff *skb)
28 {
29 	u16 queue_mapping = params->queue_mapping;
30 
31 	if (params->flags & SKBEDIT_F_TXQ_SKBHASH) {
32 		u32 hash = skb_get_hash(skb);
33 
34 		queue_mapping += hash % params->mapping_mod;
35 	}
36 
37 	return netdev_cap_txqueue(skb->dev, queue_mapping);
38 }
39 
tcf_skbedit_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)40 TC_INDIRECT_SCOPE int tcf_skbedit_act(struct sk_buff *skb,
41 				      const struct tc_action *a,
42 				      struct tcf_result *res)
43 {
44 	struct tcf_skbedit *d = to_skbedit(a);
45 	struct tcf_skbedit_params *params;
46 
47 	tcf_lastuse_update(&d->tcf_tm);
48 	bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb);
49 
50 	params = rcu_dereference_bh(d->params);
51 
52 	if (params->flags & SKBEDIT_F_PRIORITY)
53 		skb->priority = params->priority;
54 	if (params->flags & SKBEDIT_F_INHERITDSFIELD) {
55 		int wlen = skb_network_offset(skb);
56 
57 		switch (skb_protocol(skb, true)) {
58 		case htons(ETH_P_IP):
59 			wlen += sizeof(struct iphdr);
60 			if (!pskb_may_pull(skb, wlen))
61 				goto err;
62 			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
63 			break;
64 
65 		case htons(ETH_P_IPV6):
66 			wlen += sizeof(struct ipv6hdr);
67 			if (!pskb_may_pull(skb, wlen))
68 				goto err;
69 			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
70 			break;
71 		}
72 	}
73 	if (params->flags & SKBEDIT_F_QUEUE_MAPPING &&
74 	    skb->dev->real_num_tx_queues > params->queue_mapping) {
75 #ifdef CONFIG_NET_EGRESS
76 		netdev_xmit_skip_txqueue(true);
77 #endif
78 		skb_set_queue_mapping(skb, tcf_skbedit_hash(params, skb));
79 	}
80 	if (params->flags & SKBEDIT_F_MARK) {
81 		skb->mark &= ~params->mask;
82 		skb->mark |= params->mark & params->mask;
83 	}
84 	if (params->flags & SKBEDIT_F_PTYPE)
85 		skb->pkt_type = params->ptype;
86 	return params->action;
87 
88 err:
89 	qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats));
90 	return TC_ACT_SHOT;
91 }
92 
tcf_skbedit_stats_update(struct tc_action * a,u64 bytes,u64 packets,u64 drops,u64 lastuse,bool hw)93 static void tcf_skbedit_stats_update(struct tc_action *a, u64 bytes,
94 				     u64 packets, u64 drops,
95 				     u64 lastuse, bool hw)
96 {
97 	struct tcf_skbedit *d = to_skbedit(a);
98 	struct tcf_t *tm = &d->tcf_tm;
99 
100 	tcf_action_update_stats(a, bytes, packets, drops, hw);
101 	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
102 }
103 
104 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
105 	[TCA_SKBEDIT_PARMS]		= { .len = sizeof(struct tc_skbedit) },
106 	[TCA_SKBEDIT_PRIORITY]		= { .len = sizeof(u32) },
107 	[TCA_SKBEDIT_QUEUE_MAPPING]	= { .len = sizeof(u16) },
108 	[TCA_SKBEDIT_MARK]		= { .len = sizeof(u32) },
109 	[TCA_SKBEDIT_PTYPE]		= { .len = sizeof(u16) },
110 	[TCA_SKBEDIT_MASK]		= { .len = sizeof(u32) },
111 	[TCA_SKBEDIT_FLAGS]		= { .len = sizeof(u64) },
112 	[TCA_SKBEDIT_QUEUE_MAPPING_MAX]	= { .len = sizeof(u16) },
113 };
114 
tcf_skbedit_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,struct tcf_proto * tp,u32 act_flags,struct netlink_ext_ack * extack)115 static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
116 			    struct nlattr *est, struct tc_action **a,
117 			    struct tcf_proto *tp, u32 act_flags,
118 			    struct netlink_ext_ack *extack)
119 {
120 	struct tc_action_net *tn = net_generic(net, act_skbedit_ops.net_id);
121 	bool bind = act_flags & TCA_ACT_FLAGS_BIND;
122 	struct tcf_skbedit_params *params_new;
123 	struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
124 	struct tcf_chain *goto_ch = NULL;
125 	struct tc_skbedit *parm;
126 	struct tcf_skbedit *d;
127 	u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
128 	u16 *queue_mapping = NULL, *ptype = NULL;
129 	u32 mapping_mod = 1;
130 	bool exists = false;
131 	int ret = 0, err;
132 	u32 index;
133 
134 	if (nla == NULL)
135 		return -EINVAL;
136 
137 	err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla,
138 					  skbedit_policy, NULL);
139 	if (err < 0)
140 		return err;
141 
142 	if (tb[TCA_SKBEDIT_PARMS] == NULL)
143 		return -EINVAL;
144 
145 	if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
146 		flags |= SKBEDIT_F_PRIORITY;
147 		priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
148 	}
149 
150 	if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
151 		if (is_tcf_skbedit_ingress(act_flags) &&
152 		    !(act_flags & TCA_ACT_FLAGS_SKIP_SW)) {
153 			NL_SET_ERR_MSG_MOD(extack, "\"queue_mapping\" option on receive side is hardware only, use skip_sw");
154 			return -EOPNOTSUPP;
155 		}
156 		flags |= SKBEDIT_F_QUEUE_MAPPING;
157 		queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
158 	}
159 
160 	if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
161 		ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
162 		if (!skb_pkt_type_ok(*ptype))
163 			return -EINVAL;
164 		flags |= SKBEDIT_F_PTYPE;
165 	}
166 
167 	if (tb[TCA_SKBEDIT_MARK] != NULL) {
168 		flags |= SKBEDIT_F_MARK;
169 		mark = nla_data(tb[TCA_SKBEDIT_MARK]);
170 	}
171 
172 	if (tb[TCA_SKBEDIT_MASK] != NULL) {
173 		flags |= SKBEDIT_F_MASK;
174 		mask = nla_data(tb[TCA_SKBEDIT_MASK]);
175 	}
176 
177 	if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
178 		u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
179 
180 		if (*pure_flags & SKBEDIT_F_TXQ_SKBHASH) {
181 			u16 *queue_mapping_max;
182 
183 			if (!tb[TCA_SKBEDIT_QUEUE_MAPPING] ||
184 			    !tb[TCA_SKBEDIT_QUEUE_MAPPING_MAX]) {
185 				NL_SET_ERR_MSG_MOD(extack, "Missing required range of queue_mapping.");
186 				return -EINVAL;
187 			}
188 
189 			queue_mapping_max =
190 				nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING_MAX]);
191 			if (*queue_mapping_max < *queue_mapping) {
192 				NL_SET_ERR_MSG_MOD(extack, "The range of queue_mapping is invalid, max < min.");
193 				return -EINVAL;
194 			}
195 
196 			mapping_mod = *queue_mapping_max - *queue_mapping + 1;
197 			if (mapping_mod > U16_MAX) {
198 				NL_SET_ERR_MSG_MOD(extack, "The range of queue_mapping is invalid.");
199 				return -EINVAL;
200 			}
201 			flags |= SKBEDIT_F_TXQ_SKBHASH;
202 		}
203 		if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
204 			flags |= SKBEDIT_F_INHERITDSFIELD;
205 	}
206 
207 	parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
208 	index = parm->index;
209 	err = tcf_idr_check_alloc(tn, &index, a, bind);
210 	if (err < 0)
211 		return err;
212 	exists = err;
213 	if (exists && bind)
214 		return ACT_P_BOUND;
215 
216 	if (!flags) {
217 		if (exists)
218 			tcf_idr_release(*a, bind);
219 		else
220 			tcf_idr_cleanup(tn, index);
221 		return -EINVAL;
222 	}
223 
224 	if (!exists) {
225 		ret = tcf_idr_create(tn, index, est, a,
226 				     &act_skbedit_ops, bind, true, act_flags);
227 		if (ret) {
228 			tcf_idr_cleanup(tn, index);
229 			return ret;
230 		}
231 
232 		d = to_skbedit(*a);
233 		ret = ACT_P_CREATED;
234 	} else {
235 		d = to_skbedit(*a);
236 		if (!(act_flags & TCA_ACT_FLAGS_REPLACE)) {
237 			tcf_idr_release(*a, bind);
238 			return -EEXIST;
239 		}
240 	}
241 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
242 	if (err < 0)
243 		goto release_idr;
244 
245 	params_new = kzalloc_obj(*params_new);
246 	if (unlikely(!params_new)) {
247 		err = -ENOMEM;
248 		goto put_chain;
249 	}
250 
251 	params_new->flags = flags;
252 	if (flags & SKBEDIT_F_PRIORITY)
253 		params_new->priority = *priority;
254 	if (flags & SKBEDIT_F_QUEUE_MAPPING) {
255 		params_new->queue_mapping = *queue_mapping;
256 		params_new->mapping_mod = mapping_mod;
257 	}
258 	if (flags & SKBEDIT_F_MARK)
259 		params_new->mark = *mark;
260 	if (flags & SKBEDIT_F_PTYPE)
261 		params_new->ptype = *ptype;
262 	/* default behaviour is to use all the bits */
263 	params_new->mask = 0xffffffff;
264 	if (flags & SKBEDIT_F_MASK)
265 		params_new->mask = *mask;
266 
267 	params_new->action = parm->action;
268 	spin_lock_bh(&d->tcf_lock);
269 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
270 	params_new = rcu_replace_pointer(d->params, params_new,
271 					 lockdep_is_held(&d->tcf_lock));
272 	spin_unlock_bh(&d->tcf_lock);
273 	if (params_new)
274 		kfree_rcu(params_new, rcu);
275 	if (goto_ch)
276 		tcf_chain_put_by_act(goto_ch);
277 
278 	return ret;
279 put_chain:
280 	if (goto_ch)
281 		tcf_chain_put_by_act(goto_ch);
282 release_idr:
283 	tcf_idr_release(*a, bind);
284 	return err;
285 }
286 
tcf_skbedit_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)287 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
288 			    int bind, int ref)
289 {
290 	const struct tcf_skbedit *d = to_skbedit(a);
291 	unsigned char *b = skb_tail_pointer(skb);
292 	const struct tcf_skbedit_params *params;
293 	struct tc_skbedit opt = {
294 		.index   = d->tcf_index,
295 		.refcnt  = refcount_read(&d->tcf_refcnt) - ref,
296 		.bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
297 	};
298 	u64 pure_flags = 0;
299 	struct tcf_t t;
300 
301 	rcu_read_lock();
302 	params = rcu_dereference(d->params);
303 	opt.action = params->action;
304 
305 	if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
306 		goto nla_put_failure;
307 	if ((params->flags & SKBEDIT_F_PRIORITY) &&
308 	    nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority))
309 		goto nla_put_failure;
310 	if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) &&
311 	    nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping))
312 		goto nla_put_failure;
313 	if ((params->flags & SKBEDIT_F_MARK) &&
314 	    nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark))
315 		goto nla_put_failure;
316 	if ((params->flags & SKBEDIT_F_PTYPE) &&
317 	    nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype))
318 		goto nla_put_failure;
319 	if ((params->flags & SKBEDIT_F_MASK) &&
320 	    nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask))
321 		goto nla_put_failure;
322 	if (params->flags & SKBEDIT_F_INHERITDSFIELD)
323 		pure_flags |= SKBEDIT_F_INHERITDSFIELD;
324 	if (params->flags & SKBEDIT_F_TXQ_SKBHASH) {
325 		if (nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING_MAX,
326 				params->queue_mapping + params->mapping_mod - 1))
327 			goto nla_put_failure;
328 
329 		pure_flags |= SKBEDIT_F_TXQ_SKBHASH;
330 	}
331 	if (pure_flags != 0 &&
332 	    nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags))
333 		goto nla_put_failure;
334 
335 	tcf_tm_dump(&t, &d->tcf_tm);
336 	if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
337 		goto nla_put_failure;
338 	rcu_read_unlock();
339 
340 	return skb->len;
341 
342 nla_put_failure:
343 	rcu_read_unlock();
344 	nlmsg_trim(skb, b);
345 	return -1;
346 }
347 
tcf_skbedit_cleanup(struct tc_action * a)348 static void tcf_skbedit_cleanup(struct tc_action *a)
349 {
350 	struct tcf_skbedit *d = to_skbedit(a);
351 	struct tcf_skbedit_params *params;
352 
353 	params = rcu_dereference_protected(d->params, 1);
354 	if (params)
355 		kfree_rcu(params, rcu);
356 }
357 
tcf_skbedit_get_fill_size(const struct tc_action * act)358 static size_t tcf_skbedit_get_fill_size(const struct tc_action *act)
359 {
360 	return nla_total_size(sizeof(struct tc_skbedit))
361 		+ nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_PRIORITY */
362 		+ nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_QUEUE_MAPPING */
363 		+ nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_QUEUE_MAPPING_MAX */
364 		+ nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MARK */
365 		+ nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_PTYPE */
366 		+ nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MASK */
367 		+ nla_total_size_64bit(sizeof(u64)); /* TCA_SKBEDIT_FLAGS */
368 }
369 
tcf_skbedit_offload_act_setup(struct tc_action * act,void * entry_data,u32 * index_inc,bool bind,struct netlink_ext_ack * extack)370 static int tcf_skbedit_offload_act_setup(struct tc_action *act, void *entry_data,
371 					 u32 *index_inc, bool bind,
372 					 struct netlink_ext_ack *extack)
373 {
374 	if (bind) {
375 		struct flow_action_entry *entry = entry_data;
376 
377 		if (is_tcf_skbedit_mark(act)) {
378 			entry->id = FLOW_ACTION_MARK;
379 			entry->mark = tcf_skbedit_mark(act);
380 		} else if (is_tcf_skbedit_ptype(act)) {
381 			entry->id = FLOW_ACTION_PTYPE;
382 			entry->ptype = tcf_skbedit_ptype(act);
383 		} else if (is_tcf_skbedit_priority(act)) {
384 			entry->id = FLOW_ACTION_PRIORITY;
385 			entry->priority = tcf_skbedit_priority(act);
386 		} else if (is_tcf_skbedit_tx_queue_mapping(act)) {
387 			NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"queue_mapping\" option is used on transmit side");
388 			return -EOPNOTSUPP;
389 		} else if (is_tcf_skbedit_rx_queue_mapping(act)) {
390 			entry->id = FLOW_ACTION_RX_QUEUE_MAPPING;
391 			entry->rx_queue = tcf_skbedit_rx_queue_mapping(act);
392 		} else if (is_tcf_skbedit_inheritdsfield(act)) {
393 			NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"inheritdsfield\" option is used");
394 			return -EOPNOTSUPP;
395 		} else {
396 			NL_SET_ERR_MSG_MOD(extack, "Unsupported skbedit option offload");
397 			return -EOPNOTSUPP;
398 		}
399 		*index_inc = 1;
400 	} else {
401 		struct flow_offload_action *fl_action = entry_data;
402 
403 		if (is_tcf_skbedit_mark(act))
404 			fl_action->id = FLOW_ACTION_MARK;
405 		else if (is_tcf_skbedit_ptype(act))
406 			fl_action->id = FLOW_ACTION_PTYPE;
407 		else if (is_tcf_skbedit_priority(act))
408 			fl_action->id = FLOW_ACTION_PRIORITY;
409 		else if (is_tcf_skbedit_rx_queue_mapping(act))
410 			fl_action->id = FLOW_ACTION_RX_QUEUE_MAPPING;
411 		else
412 			return -EOPNOTSUPP;
413 	}
414 
415 	return 0;
416 }
417 
418 static struct tc_action_ops act_skbedit_ops = {
419 	.kind		=	"skbedit",
420 	.id		=	TCA_ID_SKBEDIT,
421 	.owner		=	THIS_MODULE,
422 	.act		=	tcf_skbedit_act,
423 	.stats_update	=	tcf_skbedit_stats_update,
424 	.dump		=	tcf_skbedit_dump,
425 	.init		=	tcf_skbedit_init,
426 	.cleanup	=	tcf_skbedit_cleanup,
427 	.get_fill_size	=	tcf_skbedit_get_fill_size,
428 	.offload_act_setup =	tcf_skbedit_offload_act_setup,
429 	.size		=	sizeof(struct tcf_skbedit),
430 };
431 MODULE_ALIAS_NET_ACT("skbedit");
432 
skbedit_init_net(struct net * net)433 static __net_init int skbedit_init_net(struct net *net)
434 {
435 	struct tc_action_net *tn = net_generic(net, act_skbedit_ops.net_id);
436 
437 	return tc_action_net_init(net, tn, &act_skbedit_ops);
438 }
439 
skbedit_exit_net(struct list_head * net_list)440 static void __net_exit skbedit_exit_net(struct list_head *net_list)
441 {
442 	tc_action_net_exit(net_list, act_skbedit_ops.net_id);
443 }
444 
445 static struct pernet_operations skbedit_net_ops = {
446 	.init = skbedit_init_net,
447 	.exit_batch = skbedit_exit_net,
448 	.id   = &act_skbedit_ops.net_id,
449 	.size = sizeof(struct tc_action_net),
450 };
451 
452 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
453 MODULE_DESCRIPTION("SKB Editing");
454 MODULE_LICENSE("GPL");
455 
skbedit_init_module(void)456 static int __init skbedit_init_module(void)
457 {
458 	return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
459 }
460 
skbedit_cleanup_module(void)461 static void __exit skbedit_cleanup_module(void)
462 {
463 	tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
464 }
465 
466 module_init(skbedit_init_module);
467 module_exit(skbedit_cleanup_module);
468