xref: /openbmc/linux/net/sched/act_vlan.c (revision d0e22329)
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 
19 #include <linux/tc_act/tc_vlan.h>
20 #include <net/tc_act/tc_vlan.h>
21 
22 static unsigned int vlan_net_id;
23 static struct tc_action_ops act_vlan_ops;
24 
25 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
26 			struct tcf_result *res)
27 {
28 	struct tcf_vlan *v = to_vlan(a);
29 	struct tcf_vlan_params *p;
30 	int action;
31 	int err;
32 	u16 tci;
33 
34 	tcf_lastuse_update(&v->tcf_tm);
35 	bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
36 
37 	/* Ensure 'data' points at mac_header prior calling vlan manipulating
38 	 * functions.
39 	 */
40 	if (skb_at_tc_ingress(skb))
41 		skb_push_rcsum(skb, skb->mac_len);
42 
43 	action = READ_ONCE(v->tcf_action);
44 
45 	p = rcu_dereference_bh(v->vlan_p);
46 
47 	switch (p->tcfv_action) {
48 	case TCA_VLAN_ACT_POP:
49 		err = skb_vlan_pop(skb);
50 		if (err)
51 			goto drop;
52 		break;
53 	case TCA_VLAN_ACT_PUSH:
54 		err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
55 				    (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
56 		if (err)
57 			goto drop;
58 		break;
59 	case TCA_VLAN_ACT_MODIFY:
60 		/* No-op if no vlan tag (either hw-accel or in-payload) */
61 		if (!skb_vlan_tagged(skb))
62 			goto out;
63 		/* extract existing tag (and guarantee no hw-accel tag) */
64 		if (skb_vlan_tag_present(skb)) {
65 			tci = skb_vlan_tag_get(skb);
66 			__vlan_hwaccel_clear_tag(skb);
67 		} else {
68 			/* in-payload vlan tag, pop it */
69 			err = __skb_vlan_pop(skb, &tci);
70 			if (err)
71 				goto drop;
72 		}
73 		/* replace the vid */
74 		tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
75 		/* replace prio bits, if tcfv_push_prio specified */
76 		if (p->tcfv_push_prio) {
77 			tci &= ~VLAN_PRIO_MASK;
78 			tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
79 		}
80 		/* put updated tci as hwaccel tag */
81 		__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
82 		break;
83 	default:
84 		BUG();
85 	}
86 
87 out:
88 	if (skb_at_tc_ingress(skb))
89 		skb_pull_rcsum(skb, skb->mac_len);
90 
91 	return action;
92 
93 drop:
94 	qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
95 	return TC_ACT_SHOT;
96 }
97 
98 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
99 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
100 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
101 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
102 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
103 };
104 
105 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
106 			 struct nlattr *est, struct tc_action **a,
107 			 int ovr, int bind, bool rtnl_held,
108 			 struct netlink_ext_ack *extack)
109 {
110 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
111 	struct nlattr *tb[TCA_VLAN_MAX + 1];
112 	struct tcf_vlan_params *p;
113 	struct tc_vlan *parm;
114 	struct tcf_vlan *v;
115 	int action;
116 	u16 push_vid = 0;
117 	__be16 push_proto = 0;
118 	u8 push_prio = 0;
119 	bool exists = false;
120 	int ret = 0, err;
121 
122 	if (!nla)
123 		return -EINVAL;
124 
125 	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
126 	if (err < 0)
127 		return err;
128 
129 	if (!tb[TCA_VLAN_PARMS])
130 		return -EINVAL;
131 	parm = nla_data(tb[TCA_VLAN_PARMS]);
132 	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
133 	if (err < 0)
134 		return err;
135 	exists = err;
136 	if (exists && bind)
137 		return 0;
138 
139 	switch (parm->v_action) {
140 	case TCA_VLAN_ACT_POP:
141 		break;
142 	case TCA_VLAN_ACT_PUSH:
143 	case TCA_VLAN_ACT_MODIFY:
144 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
145 			if (exists)
146 				tcf_idr_release(*a, bind);
147 			else
148 				tcf_idr_cleanup(tn, parm->index);
149 			return -EINVAL;
150 		}
151 		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
152 		if (push_vid >= VLAN_VID_MASK) {
153 			if (exists)
154 				tcf_idr_release(*a, bind);
155 			else
156 				tcf_idr_cleanup(tn, parm->index);
157 			return -ERANGE;
158 		}
159 
160 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
161 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
162 			switch (push_proto) {
163 			case htons(ETH_P_8021Q):
164 			case htons(ETH_P_8021AD):
165 				break;
166 			default:
167 				if (exists)
168 					tcf_idr_release(*a, bind);
169 				else
170 					tcf_idr_cleanup(tn, parm->index);
171 				return -EPROTONOSUPPORT;
172 			}
173 		} else {
174 			push_proto = htons(ETH_P_8021Q);
175 		}
176 
177 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
178 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
179 		break;
180 	default:
181 		if (exists)
182 			tcf_idr_release(*a, bind);
183 		else
184 			tcf_idr_cleanup(tn, parm->index);
185 		return -EINVAL;
186 	}
187 	action = parm->v_action;
188 
189 	if (!exists) {
190 		ret = tcf_idr_create(tn, parm->index, est, a,
191 				     &act_vlan_ops, bind, true);
192 		if (ret) {
193 			tcf_idr_cleanup(tn, parm->index);
194 			return ret;
195 		}
196 
197 		ret = ACT_P_CREATED;
198 	} else if (!ovr) {
199 		tcf_idr_release(*a, bind);
200 		return -EEXIST;
201 	}
202 
203 	v = to_vlan(*a);
204 
205 	p = kzalloc(sizeof(*p), GFP_KERNEL);
206 	if (!p) {
207 		tcf_idr_release(*a, bind);
208 		return -ENOMEM;
209 	}
210 
211 	p->tcfv_action = action;
212 	p->tcfv_push_vid = push_vid;
213 	p->tcfv_push_prio = push_prio;
214 	p->tcfv_push_proto = push_proto;
215 
216 	spin_lock_bh(&v->tcf_lock);
217 	v->tcf_action = parm->action;
218 	rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
219 	spin_unlock_bh(&v->tcf_lock);
220 
221 	if (p)
222 		kfree_rcu(p, rcu);
223 
224 	if (ret == ACT_P_CREATED)
225 		tcf_idr_insert(tn, *a);
226 	return ret;
227 }
228 
229 static void tcf_vlan_cleanup(struct tc_action *a)
230 {
231 	struct tcf_vlan *v = to_vlan(a);
232 	struct tcf_vlan_params *p;
233 
234 	p = rcu_dereference_protected(v->vlan_p, 1);
235 	if (p)
236 		kfree_rcu(p, rcu);
237 }
238 
239 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
240 			 int bind, int ref)
241 {
242 	unsigned char *b = skb_tail_pointer(skb);
243 	struct tcf_vlan *v = to_vlan(a);
244 	struct tcf_vlan_params *p;
245 	struct tc_vlan opt = {
246 		.index    = v->tcf_index,
247 		.refcnt   = refcount_read(&v->tcf_refcnt) - ref,
248 		.bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
249 	};
250 	struct tcf_t t;
251 
252 	spin_lock_bh(&v->tcf_lock);
253 	opt.action = v->tcf_action;
254 	p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
255 	opt.v_action = p->tcfv_action;
256 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
257 		goto nla_put_failure;
258 
259 	if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
260 	     p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
261 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
262 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
263 			  p->tcfv_push_proto) ||
264 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
265 					      p->tcfv_push_prio))))
266 		goto nla_put_failure;
267 
268 	tcf_tm_dump(&t, &v->tcf_tm);
269 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
270 		goto nla_put_failure;
271 	spin_unlock_bh(&v->tcf_lock);
272 
273 	return skb->len;
274 
275 nla_put_failure:
276 	spin_unlock_bh(&v->tcf_lock);
277 	nlmsg_trim(skb, b);
278 	return -1;
279 }
280 
281 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
282 			   struct netlink_callback *cb, int type,
283 			   const struct tc_action_ops *ops,
284 			   struct netlink_ext_ack *extack)
285 {
286 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
287 
288 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
289 }
290 
291 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
292 {
293 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
294 
295 	return tcf_idr_search(tn, a, index);
296 }
297 
298 static struct tc_action_ops act_vlan_ops = {
299 	.kind		=	"vlan",
300 	.type		=	TCA_ACT_VLAN,
301 	.owner		=	THIS_MODULE,
302 	.act		=	tcf_vlan_act,
303 	.dump		=	tcf_vlan_dump,
304 	.init		=	tcf_vlan_init,
305 	.cleanup	=	tcf_vlan_cleanup,
306 	.walk		=	tcf_vlan_walker,
307 	.lookup		=	tcf_vlan_search,
308 	.size		=	sizeof(struct tcf_vlan),
309 };
310 
311 static __net_init int vlan_init_net(struct net *net)
312 {
313 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
314 
315 	return tc_action_net_init(tn, &act_vlan_ops);
316 }
317 
318 static void __net_exit vlan_exit_net(struct list_head *net_list)
319 {
320 	tc_action_net_exit(net_list, vlan_net_id);
321 }
322 
323 static struct pernet_operations vlan_net_ops = {
324 	.init = vlan_init_net,
325 	.exit_batch = vlan_exit_net,
326 	.id   = &vlan_net_id,
327 	.size = sizeof(struct tc_action_net),
328 };
329 
330 static int __init vlan_init_module(void)
331 {
332 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
333 }
334 
335 static void __exit vlan_cleanup_module(void)
336 {
337 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
338 }
339 
340 module_init(vlan_init_module);
341 module_exit(vlan_cleanup_module);
342 
343 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
344 MODULE_DESCRIPTION("vlan manipulation actions");
345 MODULE_LICENSE("GPL v2");
346