xref: /openbmc/linux/net/sched/act_vlan.c (revision d2ba09c1)
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(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 	rcu_read_lock();
44 
45 	action = READ_ONCE(v->tcf_action);
46 
47 	p = rcu_dereference(v->vlan_p);
48 
49 	switch (p->tcfv_action) {
50 	case TCA_VLAN_ACT_POP:
51 		err = skb_vlan_pop(skb);
52 		if (err)
53 			goto drop;
54 		break;
55 	case TCA_VLAN_ACT_PUSH:
56 		err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
57 				    (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
58 		if (err)
59 			goto drop;
60 		break;
61 	case TCA_VLAN_ACT_MODIFY:
62 		/* No-op if no vlan tag (either hw-accel or in-payload) */
63 		if (!skb_vlan_tagged(skb))
64 			goto unlock;
65 		/* extract existing tag (and guarantee no hw-accel tag) */
66 		if (skb_vlan_tag_present(skb)) {
67 			tci = skb_vlan_tag_get(skb);
68 			skb->vlan_tci = 0;
69 		} else {
70 			/* in-payload vlan tag, pop it */
71 			err = __skb_vlan_pop(skb, &tci);
72 			if (err)
73 				goto drop;
74 		}
75 		/* replace the vid */
76 		tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
77 		/* replace prio bits, if tcfv_push_prio specified */
78 		if (p->tcfv_push_prio) {
79 			tci &= ~VLAN_PRIO_MASK;
80 			tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
81 		}
82 		/* put updated tci as hwaccel tag */
83 		__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
84 		break;
85 	default:
86 		BUG();
87 	}
88 
89 	goto unlock;
90 
91 drop:
92 	action = TC_ACT_SHOT;
93 	qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
94 
95 unlock:
96 	rcu_read_unlock();
97 	if (skb_at_tc_ingress(skb))
98 		skb_pull_rcsum(skb, skb->mac_len);
99 
100 	return action;
101 }
102 
103 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
104 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
105 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
106 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
107 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
108 };
109 
110 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
111 			 struct nlattr *est, struct tc_action **a,
112 			 int ovr, int bind, struct netlink_ext_ack *extack)
113 {
114 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
115 	struct nlattr *tb[TCA_VLAN_MAX + 1];
116 	struct tcf_vlan_params *p, *p_old;
117 	struct tc_vlan *parm;
118 	struct tcf_vlan *v;
119 	int action;
120 	u16 push_vid = 0;
121 	__be16 push_proto = 0;
122 	u8 push_prio = 0;
123 	bool exists = false;
124 	int ret = 0, err;
125 
126 	if (!nla)
127 		return -EINVAL;
128 
129 	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
130 	if (err < 0)
131 		return err;
132 
133 	if (!tb[TCA_VLAN_PARMS])
134 		return -EINVAL;
135 	parm = nla_data(tb[TCA_VLAN_PARMS]);
136 	exists = tcf_idr_check(tn, parm->index, a, bind);
137 	if (exists && bind)
138 		return 0;
139 
140 	switch (parm->v_action) {
141 	case TCA_VLAN_ACT_POP:
142 		break;
143 	case TCA_VLAN_ACT_PUSH:
144 	case TCA_VLAN_ACT_MODIFY:
145 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
146 			if (exists)
147 				tcf_idr_release(*a, bind);
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 			return -ERANGE;
155 		}
156 
157 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
158 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
159 			switch (push_proto) {
160 			case htons(ETH_P_8021Q):
161 			case htons(ETH_P_8021AD):
162 				break;
163 			default:
164 				if (exists)
165 					tcf_idr_release(*a, bind);
166 				return -EPROTONOSUPPORT;
167 			}
168 		} else {
169 			push_proto = htons(ETH_P_8021Q);
170 		}
171 
172 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
173 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
174 		break;
175 	default:
176 		if (exists)
177 			tcf_idr_release(*a, bind);
178 		return -EINVAL;
179 	}
180 	action = parm->v_action;
181 
182 	if (!exists) {
183 		ret = tcf_idr_create(tn, parm->index, est, a,
184 				     &act_vlan_ops, bind, true);
185 		if (ret)
186 			return ret;
187 
188 		ret = ACT_P_CREATED;
189 	} else {
190 		tcf_idr_release(*a, bind);
191 		if (!ovr)
192 			return -EEXIST;
193 	}
194 
195 	v = to_vlan(*a);
196 
197 	ASSERT_RTNL();
198 	p = kzalloc(sizeof(*p), GFP_KERNEL);
199 	if (!p) {
200 		if (ret == ACT_P_CREATED)
201 			tcf_idr_release(*a, bind);
202 		return -ENOMEM;
203 	}
204 
205 	v->tcf_action = parm->action;
206 
207 	p_old = rtnl_dereference(v->vlan_p);
208 
209 	p->tcfv_action = action;
210 	p->tcfv_push_vid = push_vid;
211 	p->tcfv_push_prio = push_prio;
212 	p->tcfv_push_proto = push_proto;
213 
214 	rcu_assign_pointer(v->vlan_p, p);
215 
216 	if (p_old)
217 		kfree_rcu(p_old, rcu);
218 
219 	if (ret == ACT_P_CREATED)
220 		tcf_idr_insert(tn, *a);
221 	return ret;
222 }
223 
224 static void tcf_vlan_cleanup(struct tc_action *a)
225 {
226 	struct tcf_vlan *v = to_vlan(a);
227 	struct tcf_vlan_params *p;
228 
229 	p = rcu_dereference_protected(v->vlan_p, 1);
230 	if (p)
231 		kfree_rcu(p, rcu);
232 }
233 
234 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
235 			 int bind, int ref)
236 {
237 	unsigned char *b = skb_tail_pointer(skb);
238 	struct tcf_vlan *v = to_vlan(a);
239 	struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
240 	struct tc_vlan opt = {
241 		.index    = v->tcf_index,
242 		.refcnt   = v->tcf_refcnt - ref,
243 		.bindcnt  = v->tcf_bindcnt - bind,
244 		.action   = v->tcf_action,
245 		.v_action = p->tcfv_action,
246 	};
247 	struct tcf_t t;
248 
249 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
250 		goto nla_put_failure;
251 
252 	if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
253 	     p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
254 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
255 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
256 			  p->tcfv_push_proto) ||
257 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
258 					      p->tcfv_push_prio))))
259 		goto nla_put_failure;
260 
261 	tcf_tm_dump(&t, &v->tcf_tm);
262 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
263 		goto nla_put_failure;
264 	return skb->len;
265 
266 nla_put_failure:
267 	nlmsg_trim(skb, b);
268 	return -1;
269 }
270 
271 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
272 			   struct netlink_callback *cb, int type,
273 			   const struct tc_action_ops *ops,
274 			   struct netlink_ext_ack *extack)
275 {
276 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
277 
278 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
279 }
280 
281 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index,
282 			   struct netlink_ext_ack *extack)
283 {
284 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
285 
286 	return tcf_idr_search(tn, a, index);
287 }
288 
289 static struct tc_action_ops act_vlan_ops = {
290 	.kind		=	"vlan",
291 	.type		=	TCA_ACT_VLAN,
292 	.owner		=	THIS_MODULE,
293 	.act		=	tcf_vlan,
294 	.dump		=	tcf_vlan_dump,
295 	.init		=	tcf_vlan_init,
296 	.cleanup	=	tcf_vlan_cleanup,
297 	.walk		=	tcf_vlan_walker,
298 	.lookup		=	tcf_vlan_search,
299 	.size		=	sizeof(struct tcf_vlan),
300 };
301 
302 static __net_init int vlan_init_net(struct net *net)
303 {
304 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
305 
306 	return tc_action_net_init(tn, &act_vlan_ops);
307 }
308 
309 static void __net_exit vlan_exit_net(struct list_head *net_list)
310 {
311 	tc_action_net_exit(net_list, vlan_net_id);
312 }
313 
314 static struct pernet_operations vlan_net_ops = {
315 	.init = vlan_init_net,
316 	.exit_batch = vlan_exit_net,
317 	.id   = &vlan_net_id,
318 	.size = sizeof(struct tc_action_net),
319 };
320 
321 static int __init vlan_init_module(void)
322 {
323 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
324 }
325 
326 static void __exit vlan_cleanup_module(void)
327 {
328 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
329 }
330 
331 module_init(vlan_init_module);
332 module_exit(vlan_cleanup_module);
333 
334 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
335 MODULE_DESCRIPTION("vlan manipulation actions");
336 MODULE_LICENSE("GPL v2");
337