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
 22static unsigned int vlan_net_id;
 23static struct tc_action_ops act_vlan_ops;
 24
 25static 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
 91drop:
 92	action = TC_ACT_SHOT;
 93	qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
 94
 95unlock:
 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
103static 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
110static 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
224static 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
234static 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
266nla_put_failure:
267	nlmsg_trim(skb, b);
268	return -1;
269}
270
271static 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
281static 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
289static 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
302static __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
309static void __net_exit vlan_exit_net(struct list_head *net_list)
310{
311	tc_action_net_exit(net_list, vlan_net_id);
312}
313
314static 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
321static int __init vlan_init_module(void)
322{
323	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
324}
325
326static void __exit vlan_cleanup_module(void)
327{
328	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
329}
330
331module_init(vlan_init_module);
332module_exit(vlan_cleanup_module);
333
334MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
335MODULE_DESCRIPTION("vlan manipulation actions");
336MODULE_LICENSE("GPL v2");