xref: /linux/net/sched/act_vlan.c (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
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 	int action;
30 	int err;
31 	u16 tci;
32 
33 	spin_lock(&v->tcf_lock);
34 	tcf_lastuse_update(&v->tcf_tm);
35 	bstats_update(&v->tcf_bstats, skb);
36 	action = v->tcf_action;
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 	switch (v->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, v->tcfv_push_proto, v->tcfv_push_vid |
52 				    (v->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 unlock;
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 			skb->vlan_tci = 0;
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) | v->tcfv_push_vid;
72 		/* replace prio bits, if tcfv_push_prio specified */
73 		if (v->tcfv_push_prio) {
74 			tci &= ~VLAN_PRIO_MASK;
75 			tci |= v->tcfv_push_prio << VLAN_PRIO_SHIFT;
76 		}
77 		/* put updated tci as hwaccel tag */
78 		__vlan_hwaccel_put_tag(skb, v->tcfv_push_proto, tci);
79 		break;
80 	default:
81 		BUG();
82 	}
83 
84 	goto unlock;
85 
86 drop:
87 	action = TC_ACT_SHOT;
88 	v->tcf_qstats.drops++;
89 unlock:
90 	if (skb_at_tc_ingress(skb))
91 		skb_pull_rcsum(skb, skb->mac_len);
92 
93 	spin_unlock(&v->tcf_lock);
94 	return action;
95 }
96 
97 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
98 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
99 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
100 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
101 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
102 };
103 
104 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
105 			 struct nlattr *est, struct tc_action **a,
106 			 int ovr, int bind)
107 {
108 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
109 	struct nlattr *tb[TCA_VLAN_MAX + 1];
110 	struct tc_vlan *parm;
111 	struct tcf_vlan *v;
112 	int action;
113 	__be16 push_vid = 0;
114 	__be16 push_proto = 0;
115 	u8 push_prio = 0;
116 	bool exists = false;
117 	int ret = 0, err;
118 
119 	if (!nla)
120 		return -EINVAL;
121 
122 	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
123 	if (err < 0)
124 		return err;
125 
126 	if (!tb[TCA_VLAN_PARMS])
127 		return -EINVAL;
128 	parm = nla_data(tb[TCA_VLAN_PARMS]);
129 	exists = tcf_idr_check(tn, parm->index, a, bind);
130 	if (exists && bind)
131 		return 0;
132 
133 	switch (parm->v_action) {
134 	case TCA_VLAN_ACT_POP:
135 		break;
136 	case TCA_VLAN_ACT_PUSH:
137 	case TCA_VLAN_ACT_MODIFY:
138 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
139 			if (exists)
140 				tcf_idr_release(*a, bind);
141 			return -EINVAL;
142 		}
143 		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
144 		if (push_vid >= VLAN_VID_MASK) {
145 			if (exists)
146 				tcf_idr_release(*a, bind);
147 			return -ERANGE;
148 		}
149 
150 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
151 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
152 			switch (push_proto) {
153 			case htons(ETH_P_8021Q):
154 			case htons(ETH_P_8021AD):
155 				break;
156 			default:
157 				return -EPROTONOSUPPORT;
158 			}
159 		} else {
160 			push_proto = htons(ETH_P_8021Q);
161 		}
162 
163 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
164 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
165 		break;
166 	default:
167 		if (exists)
168 			tcf_idr_release(*a, bind);
169 		return -EINVAL;
170 	}
171 	action = parm->v_action;
172 
173 	if (!exists) {
174 		ret = tcf_idr_create(tn, parm->index, est, a,
175 				     &act_vlan_ops, bind, false);
176 		if (ret)
177 			return ret;
178 
179 		ret = ACT_P_CREATED;
180 	} else {
181 		tcf_idr_release(*a, bind);
182 		if (!ovr)
183 			return -EEXIST;
184 	}
185 
186 	v = to_vlan(*a);
187 
188 	spin_lock_bh(&v->tcf_lock);
189 
190 	v->tcfv_action = action;
191 	v->tcfv_push_vid = push_vid;
192 	v->tcfv_push_prio = push_prio;
193 	v->tcfv_push_proto = push_proto;
194 
195 	v->tcf_action = parm->action;
196 
197 	spin_unlock_bh(&v->tcf_lock);
198 
199 	if (ret == ACT_P_CREATED)
200 		tcf_idr_insert(tn, *a);
201 	return ret;
202 }
203 
204 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
205 			 int bind, int ref)
206 {
207 	unsigned char *b = skb_tail_pointer(skb);
208 	struct tcf_vlan *v = to_vlan(a);
209 	struct tc_vlan opt = {
210 		.index    = v->tcf_index,
211 		.refcnt   = v->tcf_refcnt - ref,
212 		.bindcnt  = v->tcf_bindcnt - bind,
213 		.action   = v->tcf_action,
214 		.v_action = v->tcfv_action,
215 	};
216 	struct tcf_t t;
217 
218 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
219 		goto nla_put_failure;
220 
221 	if ((v->tcfv_action == TCA_VLAN_ACT_PUSH ||
222 	     v->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
223 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, v->tcfv_push_vid) ||
224 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
225 			  v->tcfv_push_proto) ||
226 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
227 					      v->tcfv_push_prio))))
228 		goto nla_put_failure;
229 
230 	tcf_tm_dump(&t, &v->tcf_tm);
231 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
232 		goto nla_put_failure;
233 	return skb->len;
234 
235 nla_put_failure:
236 	nlmsg_trim(skb, b);
237 	return -1;
238 }
239 
240 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
241 			   struct netlink_callback *cb, int type,
242 			   const struct tc_action_ops *ops)
243 {
244 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
245 
246 	return tcf_generic_walker(tn, skb, cb, type, ops);
247 }
248 
249 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
250 {
251 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
252 
253 	return tcf_idr_search(tn, a, index);
254 }
255 
256 static struct tc_action_ops act_vlan_ops = {
257 	.kind		=	"vlan",
258 	.type		=	TCA_ACT_VLAN,
259 	.owner		=	THIS_MODULE,
260 	.act		=	tcf_vlan,
261 	.dump		=	tcf_vlan_dump,
262 	.init		=	tcf_vlan_init,
263 	.walk		=	tcf_vlan_walker,
264 	.lookup		=	tcf_vlan_search,
265 	.size		=	sizeof(struct tcf_vlan),
266 };
267 
268 static __net_init int vlan_init_net(struct net *net)
269 {
270 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
271 
272 	return tc_action_net_init(tn, &act_vlan_ops);
273 }
274 
275 static void __net_exit vlan_exit_net(struct net *net)
276 {
277 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
278 
279 	tc_action_net_exit(tn);
280 }
281 
282 static struct pernet_operations vlan_net_ops = {
283 	.init = vlan_init_net,
284 	.exit = vlan_exit_net,
285 	.id   = &vlan_net_id,
286 	.size = sizeof(struct tc_action_net),
287 };
288 
289 static int __init vlan_init_module(void)
290 {
291 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
292 }
293 
294 static void __exit vlan_cleanup_module(void)
295 {
296 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
297 }
298 
299 module_init(vlan_init_module);
300 module_exit(vlan_cleanup_module);
301 
302 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
303 MODULE_DESCRIPTION("vlan manipulation actions");
304 MODULE_LICENSE("GPL v2");
305