xref: /linux/net/sched/act_vlan.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 #define VLAN_TAB_MASK     15
23 
24 static int vlan_net_id;
25 static struct tc_action_ops act_vlan_ops;
26 
27 static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
28 		    struct tcf_result *res)
29 {
30 	struct tcf_vlan *v = to_vlan(a);
31 	int action;
32 	int err;
33 	u16 tci;
34 
35 	spin_lock(&v->tcf_lock);
36 	tcf_lastuse_update(&v->tcf_tm);
37 	bstats_update(&v->tcf_bstats, skb);
38 	action = v->tcf_action;
39 
40 	/* Ensure 'data' points at mac_header prior calling vlan manipulating
41 	 * functions.
42 	 */
43 	if (skb_at_tc_ingress(skb))
44 		skb_push_rcsum(skb, skb->mac_len);
45 
46 	switch (v->tcfv_action) {
47 	case TCA_VLAN_ACT_POP:
48 		err = skb_vlan_pop(skb);
49 		if (err)
50 			goto drop;
51 		break;
52 	case TCA_VLAN_ACT_PUSH:
53 		err = skb_vlan_push(skb, v->tcfv_push_proto, v->tcfv_push_vid |
54 				    (v->tcfv_push_prio << VLAN_PRIO_SHIFT));
55 		if (err)
56 			goto drop;
57 		break;
58 	case TCA_VLAN_ACT_MODIFY:
59 		/* No-op if no vlan tag (either hw-accel or in-payload) */
60 		if (!skb_vlan_tagged(skb))
61 			goto unlock;
62 		/* extract existing tag (and guarantee no hw-accel tag) */
63 		if (skb_vlan_tag_present(skb)) {
64 			tci = skb_vlan_tag_get(skb);
65 			skb->vlan_tci = 0;
66 		} else {
67 			/* in-payload vlan tag, pop it */
68 			err = __skb_vlan_pop(skb, &tci);
69 			if (err)
70 				goto drop;
71 		}
72 		/* replace the vid */
73 		tci = (tci & ~VLAN_VID_MASK) | v->tcfv_push_vid;
74 		/* replace prio bits, if tcfv_push_prio specified */
75 		if (v->tcfv_push_prio) {
76 			tci &= ~VLAN_PRIO_MASK;
77 			tci |= v->tcfv_push_prio << VLAN_PRIO_SHIFT;
78 		}
79 		/* put updated tci as hwaccel tag */
80 		__vlan_hwaccel_put_tag(skb, v->tcfv_push_proto, tci);
81 		break;
82 	default:
83 		BUG();
84 	}
85 
86 	goto unlock;
87 
88 drop:
89 	action = TC_ACT_SHOT;
90 	v->tcf_qstats.drops++;
91 unlock:
92 	if (skb_at_tc_ingress(skb))
93 		skb_pull_rcsum(skb, skb->mac_len);
94 
95 	spin_unlock(&v->tcf_lock);
96 	return action;
97 }
98 
99 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
100 	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
101 	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
102 	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
103 	[TCA_VLAN_PUSH_VLAN_PRIORITY]	= { .type = NLA_U8 },
104 };
105 
106 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
107 			 struct nlattr *est, struct tc_action **a,
108 			 int ovr, int bind)
109 {
110 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
111 	struct nlattr *tb[TCA_VLAN_MAX + 1];
112 	struct tc_vlan *parm;
113 	struct tcf_vlan *v;
114 	int action;
115 	__be16 push_vid = 0;
116 	__be16 push_proto = 0;
117 	u8 push_prio = 0;
118 	bool exists = false;
119 	int ret = 0, err;
120 
121 	if (!nla)
122 		return -EINVAL;
123 
124 	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy);
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 	exists = tcf_hash_check(tn, parm->index, a, bind);
132 	if (exists && bind)
133 		return 0;
134 
135 	switch (parm->v_action) {
136 	case TCA_VLAN_ACT_POP:
137 		break;
138 	case TCA_VLAN_ACT_PUSH:
139 	case TCA_VLAN_ACT_MODIFY:
140 		if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
141 			if (exists)
142 				tcf_hash_release(*a, bind);
143 			return -EINVAL;
144 		}
145 		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
146 		if (push_vid >= VLAN_VID_MASK) {
147 			if (exists)
148 				tcf_hash_release(*a, bind);
149 			return -ERANGE;
150 		}
151 
152 		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
153 			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
154 			switch (push_proto) {
155 			case htons(ETH_P_8021Q):
156 			case htons(ETH_P_8021AD):
157 				break;
158 			default:
159 				return -EPROTONOSUPPORT;
160 			}
161 		} else {
162 			push_proto = htons(ETH_P_8021Q);
163 		}
164 
165 		if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
166 			push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
167 		break;
168 	default:
169 		if (exists)
170 			tcf_hash_release(*a, bind);
171 		return -EINVAL;
172 	}
173 	action = parm->v_action;
174 
175 	if (!exists) {
176 		ret = tcf_hash_create(tn, parm->index, est, a,
177 				      &act_vlan_ops, bind, false);
178 		if (ret)
179 			return ret;
180 
181 		ret = ACT_P_CREATED;
182 	} else {
183 		tcf_hash_release(*a, bind);
184 		if (!ovr)
185 			return -EEXIST;
186 	}
187 
188 	v = to_vlan(*a);
189 
190 	spin_lock_bh(&v->tcf_lock);
191 
192 	v->tcfv_action = action;
193 	v->tcfv_push_vid = push_vid;
194 	v->tcfv_push_prio = push_prio;
195 	v->tcfv_push_proto = push_proto;
196 
197 	v->tcf_action = parm->action;
198 
199 	spin_unlock_bh(&v->tcf_lock);
200 
201 	if (ret == ACT_P_CREATED)
202 		tcf_hash_insert(tn, *a);
203 	return ret;
204 }
205 
206 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
207 			 int bind, int ref)
208 {
209 	unsigned char *b = skb_tail_pointer(skb);
210 	struct tcf_vlan *v = to_vlan(a);
211 	struct tc_vlan opt = {
212 		.index    = v->tcf_index,
213 		.refcnt   = v->tcf_refcnt - ref,
214 		.bindcnt  = v->tcf_bindcnt - bind,
215 		.action   = v->tcf_action,
216 		.v_action = v->tcfv_action,
217 	};
218 	struct tcf_t t;
219 
220 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
221 		goto nla_put_failure;
222 
223 	if ((v->tcfv_action == TCA_VLAN_ACT_PUSH ||
224 	     v->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
225 	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, v->tcfv_push_vid) ||
226 	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
227 			  v->tcfv_push_proto) ||
228 	     (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
229 					      v->tcfv_push_prio))))
230 		goto nla_put_failure;
231 
232 	tcf_tm_dump(&t, &v->tcf_tm);
233 	if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
234 		goto nla_put_failure;
235 	return skb->len;
236 
237 nla_put_failure:
238 	nlmsg_trim(skb, b);
239 	return -1;
240 }
241 
242 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
243 			   struct netlink_callback *cb, int type,
244 			   const struct tc_action_ops *ops)
245 {
246 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
247 
248 	return tcf_generic_walker(tn, skb, cb, type, ops);
249 }
250 
251 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
252 {
253 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
254 
255 	return tcf_hash_search(tn, a, index);
256 }
257 
258 static struct tc_action_ops act_vlan_ops = {
259 	.kind		=	"vlan",
260 	.type		=	TCA_ACT_VLAN,
261 	.owner		=	THIS_MODULE,
262 	.act		=	tcf_vlan,
263 	.dump		=	tcf_vlan_dump,
264 	.init		=	tcf_vlan_init,
265 	.walk		=	tcf_vlan_walker,
266 	.lookup		=	tcf_vlan_search,
267 	.size		=	sizeof(struct tcf_vlan),
268 };
269 
270 static __net_init int vlan_init_net(struct net *net)
271 {
272 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
273 
274 	return tc_action_net_init(tn, &act_vlan_ops, VLAN_TAB_MASK);
275 }
276 
277 static void __net_exit vlan_exit_net(struct net *net)
278 {
279 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
280 
281 	tc_action_net_exit(tn);
282 }
283 
284 static struct pernet_operations vlan_net_ops = {
285 	.init = vlan_init_net,
286 	.exit = vlan_exit_net,
287 	.id   = &vlan_net_id,
288 	.size = sizeof(struct tc_action_net),
289 };
290 
291 static int __init vlan_init_module(void)
292 {
293 	return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
294 }
295 
296 static void __exit vlan_cleanup_module(void)
297 {
298 	tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
299 }
300 
301 module_init(vlan_init_module);
302 module_exit(vlan_cleanup_module);
303 
304 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
305 MODULE_DESCRIPTION("vlan manipulation actions");
306 MODULE_LICENSE("GPL v2");
307