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