xref: /openbmc/linux/net/sched/act_vlan.c (revision 4419617e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
4  */
5 
6 #include <linux/module.h>
7 #include <linux/init.h>
8 #include <linux/kernel.h>
9 #include <linux/skbuff.h>
10 #include <linux/rtnetlink.h>
11 #include <linux/if_vlan.h>
12 #include <net/netlink.h>
13 #include <net/pkt_sched.h>
14 #include <net/pkt_cls.h>
15 
16 #include <linux/tc_act/tc_vlan.h>
17 #include <net/tc_act/tc_vlan.h>
18 
19 static unsigned int vlan_net_id;
20 static struct tc_action_ops act_vlan_ops;
21 
22 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
23 			struct tcf_result *res)
24 {
25 	struct tcf_vlan *v = to_vlan(a);
26 	struct tcf_vlan_params *p;
27 	int action;
28 	int err;
29 	u16 tci;
30 
31 	tcf_lastuse_update(&v->tcf_tm);
32 	bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
33 
34 	/* Ensure 'data' points at mac_header prior calling vlan manipulating
35 	 * functions.
36 	 */
37 	if (skb_at_tc_ingress(skb))
38 		skb_push_rcsum(skb, skb->mac_len);
39 
40 	action = READ_ONCE(v->tcf_action);
41 
42 	p = rcu_dereference_bh(v->vlan_p);
43 
44 	switch (p->tcfv_action) {
45 	case TCA_VLAN_ACT_POP:
46 		err = skb_vlan_pop(skb);
47 		if (err)
48 			goto drop;
49 		break;
50 	case TCA_VLAN_ACT_PUSH:
51 		err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
52 				    (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
53 		if (err)
54 			goto drop;
55 		break;
56 	case TCA_VLAN_ACT_MODIFY:
57 		/* No-op if no vlan tag (either hw-accel or in-payload) */
58 		if (!skb_vlan_tagged(skb))
59 			goto out;
60 		/* extract existing tag (and guarantee no hw-accel tag) */
61 		if (skb_vlan_tag_present(skb)) {
62 			tci = skb_vlan_tag_get(skb);
63 			__vlan_hwaccel_clear_tag(skb);
64 		} else {
65 			/* in-payload vlan tag, pop it */
66 			err = __skb_vlan_pop(skb, &tci);
67 			if (err)
68 				goto drop;
69 		}
70 		/* replace the vid */
71 		tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
72 		/* replace prio bits, if tcfv_push_prio specified */
73 		if (p->tcfv_push_prio) {
74 			tci &= ~VLAN_PRIO_MASK;
75 			tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
76 		}
77 		/* put updated tci as hwaccel tag */
78 		__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
79 		break;
80 	default:
81 		BUG();
82 	}
83 
84 out:
85 	if (skb_at_tc_ingress(skb))
86 		skb_pull_rcsum(skb, skb->mac_len);
87 
88 	return action;
89 
90 drop:
91 	qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
92 	return TC_ACT_SHOT;
93 }
94 
95 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
96 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
97 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
98 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
99 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
100 };
101 
102 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
103 			 struct nlattr *est, struct tc_action **a,
104 			 int ovr, int bind, bool rtnl_held,
105 			 struct tcf_proto *tp, struct netlink_ext_ack *extack)
106 {
107 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
108 	struct nlattr *tb[TCA_VLAN_MAX + 1];
109 	struct tcf_chain *goto_ch = NULL;
110 	struct tcf_vlan_params *p;
111 	struct tc_vlan *parm;
112 	struct tcf_vlan *v;
113 	int action;
114 	u16 push_vid = 0;
115 	__be16 push_proto = 0;
116 	u8 push_prio = 0;
117 	bool exists = false;
118 	int ret = 0, err;
119 
120 	if (!nla)
121 		return -EINVAL;
122 
123 	err = nla_parse_nested_deprecated(tb, TCA_VLAN_MAX, nla, vlan_policy,
124 					  NULL);
125 	if (err < 0)
126 		return err;
127 
128 	if (!tb[TCA_VLAN_PARMS])
129 		return -EINVAL;
130 	parm = nla_data(tb[TCA_VLAN_PARMS]);
131 	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
132 	if (err < 0)
133 		return err;
134 	exists = err;
135 	if (exists && bind)
136 		return 0;
137 
138 	switch (parm->v_action) {
139 	case TCA_VLAN_ACT_POP:
140 		break;
141 	case TCA_VLAN_ACT_PUSH:
142 	case TCA_VLAN_ACT_MODIFY:
143 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
144 			if (exists)
145 				tcf_idr_release(*a, bind);
146 			else
147 				tcf_idr_cleanup(tn, parm->index);
148 			return -EINVAL;
149 		}
150 		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
151 		if (push_vid >= VLAN_VID_MASK) {
152 			if (exists)
153 				tcf_idr_release(*a, bind);
154 			else
155 				tcf_idr_cleanup(tn, parm->index);
156 			return -ERANGE;
157 		}
158 
159 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
160 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
161 			switch (push_proto) {
162 			case htons(ETH_P_8021Q):
163 			case htons(ETH_P_8021AD):
164 				break;
165 			default:
166 				if (exists)
167 					tcf_idr_release(*a, bind);
168 				else
169 					tcf_idr_cleanup(tn, parm->index);
170 				return -EPROTONOSUPPORT;
171 			}
172 		} else {
173 			push_proto = htons(ETH_P_8021Q);
174 		}
175 
176 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
177 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
178 		break;
179 	default:
180 		if (exists)
181 			tcf_idr_release(*a, bind);
182 		else
183 			tcf_idr_cleanup(tn, parm->index);
184 		return -EINVAL;
185 	}
186 	action = parm->v_action;
187 
188 	if (!exists) {
189 		ret = tcf_idr_create(tn, parm->index, est, a,
190 				     &act_vlan_ops, bind, true);
191 		if (ret) {
192 			tcf_idr_cleanup(tn, parm->index);
193 			return ret;
194 		}
195 
196 		ret = ACT_P_CREATED;
197 	} else if (!ovr) {
198 		tcf_idr_release(*a, bind);
199 		return -EEXIST;
200 	}
201 
202 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
203 	if (err < 0)
204 		goto release_idr;
205 
206 	v = to_vlan(*a);
207 
208 	p = kzalloc(sizeof(*p), GFP_KERNEL);
209 	if (!p) {
210 		err = -ENOMEM;
211 		goto put_chain;
212 	}
213 
214 	p->tcfv_action = action;
215 	p->tcfv_push_vid = push_vid;
216 	p->tcfv_push_prio = push_prio;
217 	p->tcfv_push_proto = push_proto;
218 
219 	spin_lock_bh(&v->tcf_lock);
220 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
221 	rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
222 	spin_unlock_bh(&v->tcf_lock);
223 
224 	if (goto_ch)
225 		tcf_chain_put_by_act(goto_ch);
226 	if (p)
227 		kfree_rcu(p, rcu);
228 
229 	if (ret == ACT_P_CREATED)
230 		tcf_idr_insert(tn, *a);
231 	return ret;
232 put_chain:
233 	if (goto_ch)
234 		tcf_chain_put_by_act(goto_ch);
235 release_idr:
236 	tcf_idr_release(*a, bind);
237 	return err;
238 }
239 
240 static void tcf_vlan_cleanup(struct tc_action *a)
241 {
242 	struct tcf_vlan *v = to_vlan(a);
243 	struct tcf_vlan_params *p;
244 
245 	p = rcu_dereference_protected(v->vlan_p, 1);
246 	if (p)
247 		kfree_rcu(p, rcu);
248 }
249 
250 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
251 			 int bind, int ref)
252 {
253 	unsigned char *b = skb_tail_pointer(skb);
254 	struct tcf_vlan *v = to_vlan(a);
255 	struct tcf_vlan_params *p;
256 	struct tc_vlan opt = {
257 		.index    = v->tcf_index,
258 		.refcnt   = refcount_read(&v->tcf_refcnt) - ref,
259 		.bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
260 	};
261 	struct tcf_t t;
262 
263 	spin_lock_bh(&v->tcf_lock);
264 	opt.action = v->tcf_action;
265 	p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
266 	opt.v_action = p->tcfv_action;
267 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
268 		goto nla_put_failure;
269 
270 	if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
271 	     p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
272 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
273 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
274 			  p->tcfv_push_proto) ||
275 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
276 					      p->tcfv_push_prio))))
277 		goto nla_put_failure;
278 
279 	tcf_tm_dump(&t, &v->tcf_tm);
280 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
281 		goto nla_put_failure;
282 	spin_unlock_bh(&v->tcf_lock);
283 
284 	return skb->len;
285 
286 nla_put_failure:
287 	spin_unlock_bh(&v->tcf_lock);
288 	nlmsg_trim(skb, b);
289 	return -1;
290 }
291 
292 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
293 			   struct netlink_callback *cb, int type,
294 			   const struct tc_action_ops *ops,
295 			   struct netlink_ext_ack *extack)
296 {
297 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
298 
299 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
300 }
301 
302 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
303 {
304 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
305 
306 	return tcf_idr_search(tn, a, index);
307 }
308 
309 static struct tc_action_ops act_vlan_ops = {
310 	.kind		=	"vlan",
311 	.id		=	TCA_ID_VLAN,
312 	.owner		=	THIS_MODULE,
313 	.act		=	tcf_vlan_act,
314 	.dump		=	tcf_vlan_dump,
315 	.init		=	tcf_vlan_init,
316 	.cleanup	=	tcf_vlan_cleanup,
317 	.walk		=	tcf_vlan_walker,
318 	.lookup		=	tcf_vlan_search,
319 	.size		=	sizeof(struct tcf_vlan),
320 };
321 
322 static __net_init int vlan_init_net(struct net *net)
323 {
324 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
325 
326 	return tc_action_net_init(tn, &act_vlan_ops);
327 }
328 
329 static void __net_exit vlan_exit_net(struct list_head *net_list)
330 {
331 	tc_action_net_exit(net_list, vlan_net_id);
332 }
333 
334 static struct pernet_operations vlan_net_ops = {
335 	.init = vlan_init_net,
336 	.exit_batch = vlan_exit_net,
337 	.id   = &vlan_net_id,
338 	.size = sizeof(struct tc_action_net),
339 };
340 
341 static int __init vlan_init_module(void)
342 {
343 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
344 }
345 
346 static void __exit vlan_cleanup_module(void)
347 {
348 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
349 }
350 
351 module_init(vlan_init_module);
352 module_exit(vlan_cleanup_module);
353 
354 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
355 MODULE_DESCRIPTION("vlan manipulation actions");
356 MODULE_LICENSE("GPL v2");
357