xref: /linux/net/sched/act_vlan.c (revision 8f8d5745bb520c76b81abef4a2cb3023d0313bfd)
1 /*
2  * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/if_vlan.h>
16 #include <net/netlink.h>
17 #include <net/pkt_sched.h>
18 #include <net/pkt_cls.h>
19 
20 #include <linux/tc_act/tc_vlan.h>
21 #include <net/tc_act/tc_vlan.h>
22 
23 static unsigned int vlan_net_id;
24 static struct tc_action_ops act_vlan_ops;
25 
26 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
27 			struct tcf_result *res)
28 {
29 	struct tcf_vlan *v = to_vlan(a);
30 	struct tcf_vlan_params *p;
31 	int action;
32 	int err;
33 	u16 tci;
34 
35 	tcf_lastuse_update(&v->tcf_tm);
36 	bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
37 
38 	/* Ensure 'data' points at mac_header prior calling vlan manipulating
39 	 * functions.
40 	 */
41 	if (skb_at_tc_ingress(skb))
42 		skb_push_rcsum(skb, skb->mac_len);
43 
44 	action = READ_ONCE(v->tcf_action);
45 
46 	p = rcu_dereference_bh(v->vlan_p);
47 
48 	switch (p->tcfv_action) {
49 	case TCA_VLAN_ACT_POP:
50 		err = skb_vlan_pop(skb);
51 		if (err)
52 			goto drop;
53 		break;
54 	case TCA_VLAN_ACT_PUSH:
55 		err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
56 				    (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
57 		if (err)
58 			goto drop;
59 		break;
60 	case TCA_VLAN_ACT_MODIFY:
61 		/* No-op if no vlan tag (either hw-accel or in-payload) */
62 		if (!skb_vlan_tagged(skb))
63 			goto out;
64 		/* extract existing tag (and guarantee no hw-accel tag) */
65 		if (skb_vlan_tag_present(skb)) {
66 			tci = skb_vlan_tag_get(skb);
67 			__vlan_hwaccel_clear_tag(skb);
68 		} else {
69 			/* in-payload vlan tag, pop it */
70 			err = __skb_vlan_pop(skb, &tci);
71 			if (err)
72 				goto drop;
73 		}
74 		/* replace the vid */
75 		tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
76 		/* replace prio bits, if tcfv_push_prio specified */
77 		if (p->tcfv_push_prio) {
78 			tci &= ~VLAN_PRIO_MASK;
79 			tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
80 		}
81 		/* put updated tci as hwaccel tag */
82 		__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
83 		break;
84 	default:
85 		BUG();
86 	}
87 
88 out:
89 	if (skb_at_tc_ingress(skb))
90 		skb_pull_rcsum(skb, skb->mac_len);
91 
92 	return action;
93 
94 drop:
95 	qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
96 	return TC_ACT_SHOT;
97 }
98 
99 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
100 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
101 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
102 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
103 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
104 };
105 
106 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
107 			 struct nlattr *est, struct tc_action **a,
108 			 int ovr, int bind, bool rtnl_held,
109 			 struct tcf_proto *tp, struct netlink_ext_ack *extack)
110 {
111 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
112 	struct nlattr *tb[TCA_VLAN_MAX + 1];
113 	struct tcf_chain *goto_ch = NULL;
114 	struct tcf_vlan_params *p;
115 	struct tc_vlan *parm;
116 	struct tcf_vlan *v;
117 	int action;
118 	u16 push_vid = 0;
119 	__be16 push_proto = 0;
120 	u8 push_prio = 0;
121 	bool exists = false;
122 	int ret = 0, err;
123 
124 	if (!nla)
125 		return -EINVAL;
126 
127 	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
128 	if (err < 0)
129 		return err;
130 
131 	if (!tb[TCA_VLAN_PARMS])
132 		return -EINVAL;
133 	parm = nla_data(tb[TCA_VLAN_PARMS]);
134 	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
135 	if (err < 0)
136 		return err;
137 	exists = err;
138 	if (exists && bind)
139 		return 0;
140 
141 	switch (parm->v_action) {
142 	case TCA_VLAN_ACT_POP:
143 		break;
144 	case TCA_VLAN_ACT_PUSH:
145 	case TCA_VLAN_ACT_MODIFY:
146 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
147 			if (exists)
148 				tcf_idr_release(*a, bind);
149 			else
150 				tcf_idr_cleanup(tn, parm->index);
151 			return -EINVAL;
152 		}
153 		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
154 		if (push_vid >= VLAN_VID_MASK) {
155 			if (exists)
156 				tcf_idr_release(*a, bind);
157 			else
158 				tcf_idr_cleanup(tn, parm->index);
159 			return -ERANGE;
160 		}
161 
162 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
163 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
164 			switch (push_proto) {
165 			case htons(ETH_P_8021Q):
166 			case htons(ETH_P_8021AD):
167 				break;
168 			default:
169 				if (exists)
170 					tcf_idr_release(*a, bind);
171 				else
172 					tcf_idr_cleanup(tn, parm->index);
173 				return -EPROTONOSUPPORT;
174 			}
175 		} else {
176 			push_proto = htons(ETH_P_8021Q);
177 		}
178 
179 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
180 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
181 		break;
182 	default:
183 		if (exists)
184 			tcf_idr_release(*a, bind);
185 		else
186 			tcf_idr_cleanup(tn, parm->index);
187 		return -EINVAL;
188 	}
189 	action = parm->v_action;
190 
191 	if (!exists) {
192 		ret = tcf_idr_create(tn, parm->index, est, a,
193 				     &act_vlan_ops, bind, true);
194 		if (ret) {
195 			tcf_idr_cleanup(tn, parm->index);
196 			return ret;
197 		}
198 
199 		ret = ACT_P_CREATED;
200 	} else if (!ovr) {
201 		tcf_idr_release(*a, bind);
202 		return -EEXIST;
203 	}
204 
205 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
206 	if (err < 0)
207 		goto release_idr;
208 
209 	v = to_vlan(*a);
210 
211 	p = kzalloc(sizeof(*p), GFP_KERNEL);
212 	if (!p) {
213 		err = -ENOMEM;
214 		goto put_chain;
215 	}
216 
217 	p->tcfv_action = action;
218 	p->tcfv_push_vid = push_vid;
219 	p->tcfv_push_prio = push_prio;
220 	p->tcfv_push_proto = push_proto;
221 
222 	spin_lock_bh(&v->tcf_lock);
223 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
224 	rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
225 	spin_unlock_bh(&v->tcf_lock);
226 
227 	if (goto_ch)
228 		tcf_chain_put_by_act(goto_ch);
229 	if (p)
230 		kfree_rcu(p, rcu);
231 
232 	if (ret == ACT_P_CREATED)
233 		tcf_idr_insert(tn, *a);
234 	return ret;
235 put_chain:
236 	if (goto_ch)
237 		tcf_chain_put_by_act(goto_ch);
238 release_idr:
239 	tcf_idr_release(*a, bind);
240 	return err;
241 }
242 
243 static void tcf_vlan_cleanup(struct tc_action *a)
244 {
245 	struct tcf_vlan *v = to_vlan(a);
246 	struct tcf_vlan_params *p;
247 
248 	p = rcu_dereference_protected(v->vlan_p, 1);
249 	if (p)
250 		kfree_rcu(p, rcu);
251 }
252 
253 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
254 			 int bind, int ref)
255 {
256 	unsigned char *b = skb_tail_pointer(skb);
257 	struct tcf_vlan *v = to_vlan(a);
258 	struct tcf_vlan_params *p;
259 	struct tc_vlan opt = {
260 		.index    = v->tcf_index,
261 		.refcnt   = refcount_read(&v->tcf_refcnt) - ref,
262 		.bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
263 	};
264 	struct tcf_t t;
265 
266 	spin_lock_bh(&v->tcf_lock);
267 	opt.action = v->tcf_action;
268 	p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
269 	opt.v_action = p->tcfv_action;
270 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
271 		goto nla_put_failure;
272 
273 	if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
274 	     p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
275 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
276 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
277 			  p->tcfv_push_proto) ||
278 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
279 					      p->tcfv_push_prio))))
280 		goto nla_put_failure;
281 
282 	tcf_tm_dump(&t, &v->tcf_tm);
283 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
284 		goto nla_put_failure;
285 	spin_unlock_bh(&v->tcf_lock);
286 
287 	return skb->len;
288 
289 nla_put_failure:
290 	spin_unlock_bh(&v->tcf_lock);
291 	nlmsg_trim(skb, b);
292 	return -1;
293 }
294 
295 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
296 			   struct netlink_callback *cb, int type,
297 			   const struct tc_action_ops *ops,
298 			   struct netlink_ext_ack *extack)
299 {
300 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
301 
302 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
303 }
304 
305 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
306 {
307 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
308 
309 	return tcf_idr_search(tn, a, index);
310 }
311 
312 static struct tc_action_ops act_vlan_ops = {
313 	.kind		=	"vlan",
314 	.id		=	TCA_ID_VLAN,
315 	.owner		=	THIS_MODULE,
316 	.act		=	tcf_vlan_act,
317 	.dump		=	tcf_vlan_dump,
318 	.init		=	tcf_vlan_init,
319 	.cleanup	=	tcf_vlan_cleanup,
320 	.walk		=	tcf_vlan_walker,
321 	.lookup		=	tcf_vlan_search,
322 	.size		=	sizeof(struct tcf_vlan),
323 };
324 
325 static __net_init int vlan_init_net(struct net *net)
326 {
327 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
328 
329 	return tc_action_net_init(tn, &act_vlan_ops);
330 }
331 
332 static void __net_exit vlan_exit_net(struct list_head *net_list)
333 {
334 	tc_action_net_exit(net_list, vlan_net_id);
335 }
336 
337 static struct pernet_operations vlan_net_ops = {
338 	.init = vlan_init_net,
339 	.exit_batch = vlan_exit_net,
340 	.id   = &vlan_net_id,
341 	.size = sizeof(struct tc_action_net),
342 };
343 
344 static int __init vlan_init_module(void)
345 {
346 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
347 }
348 
349 static void __exit vlan_cleanup_module(void)
350 {
351 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
352 }
353 
354 module_init(vlan_init_module);
355 module_exit(vlan_cleanup_module);
356 
357 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
358 MODULE_DESCRIPTION("vlan manipulation actions");
359 MODULE_LICENSE("GPL v2");
360