xref: /linux/net/sched/act_skbedit.c (revision 5bdd5fbb35ab0fe21bf2263106f51c5bee466a07)
1 /*
2  * Copyright (c) 2008, Intel Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, see <http://www.gnu.org/licenses/>.
15  *
16  * Author: Alexander Duyck <alexander.h.duyck@intel.com>
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/skbuff.h>
23 #include <linux/rtnetlink.h>
24 #include <net/netlink.h>
25 #include <net/pkt_sched.h>
26 
27 #include <linux/tc_act/tc_skbedit.h>
28 #include <net/tc_act/tc_skbedit.h>
29 
30 static unsigned int skbedit_net_id;
31 static struct tc_action_ops act_skbedit_ops;
32 
33 static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a,
34 		       struct tcf_result *res)
35 {
36 	struct tcf_skbedit *d = to_skbedit(a);
37 
38 	spin_lock(&d->tcf_lock);
39 	tcf_lastuse_update(&d->tcf_tm);
40 	bstats_update(&d->tcf_bstats, skb);
41 
42 	if (d->flags & SKBEDIT_F_PRIORITY)
43 		skb->priority = d->priority;
44 	if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
45 	    skb->dev->real_num_tx_queues > d->queue_mapping)
46 		skb_set_queue_mapping(skb, d->queue_mapping);
47 	if (d->flags & SKBEDIT_F_MARK) {
48 		skb->mark &= ~d->mask;
49 		skb->mark |= d->mark & d->mask;
50 	}
51 	if (d->flags & SKBEDIT_F_PTYPE)
52 		skb->pkt_type = d->ptype;
53 
54 	spin_unlock(&d->tcf_lock);
55 	return d->tcf_action;
56 }
57 
58 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
59 	[TCA_SKBEDIT_PARMS]		= { .len = sizeof(struct tc_skbedit) },
60 	[TCA_SKBEDIT_PRIORITY]		= { .len = sizeof(u32) },
61 	[TCA_SKBEDIT_QUEUE_MAPPING]	= { .len = sizeof(u16) },
62 	[TCA_SKBEDIT_MARK]		= { .len = sizeof(u32) },
63 	[TCA_SKBEDIT_PTYPE]		= { .len = sizeof(u16) },
64 	[TCA_SKBEDIT_MASK]		= { .len = sizeof(u32) },
65 };
66 
67 static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
68 			    struct nlattr *est, struct tc_action **a,
69 			    int ovr, int bind, struct netlink_ext_ack *extack)
70 {
71 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
72 	struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
73 	struct tc_skbedit *parm;
74 	struct tcf_skbedit *d;
75 	u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
76 	u16 *queue_mapping = NULL, *ptype = NULL;
77 	bool exists = false;
78 	int ret = 0, err;
79 
80 	if (nla == NULL)
81 		return -EINVAL;
82 
83 	err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL);
84 	if (err < 0)
85 		return err;
86 
87 	if (tb[TCA_SKBEDIT_PARMS] == NULL)
88 		return -EINVAL;
89 
90 	if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
91 		flags |= SKBEDIT_F_PRIORITY;
92 		priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
93 	}
94 
95 	if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
96 		flags |= SKBEDIT_F_QUEUE_MAPPING;
97 		queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
98 	}
99 
100 	if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
101 		ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
102 		if (!skb_pkt_type_ok(*ptype))
103 			return -EINVAL;
104 		flags |= SKBEDIT_F_PTYPE;
105 	}
106 
107 	if (tb[TCA_SKBEDIT_MARK] != NULL) {
108 		flags |= SKBEDIT_F_MARK;
109 		mark = nla_data(tb[TCA_SKBEDIT_MARK]);
110 	}
111 
112 	if (tb[TCA_SKBEDIT_MASK] != NULL) {
113 		flags |= SKBEDIT_F_MASK;
114 		mask = nla_data(tb[TCA_SKBEDIT_MASK]);
115 	}
116 
117 	parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
118 
119 	exists = tcf_idr_check(tn, parm->index, a, bind);
120 	if (exists && bind)
121 		return 0;
122 
123 	if (!flags) {
124 		if (exists)
125 			tcf_idr_release(*a, bind);
126 		return -EINVAL;
127 	}
128 
129 	if (!exists) {
130 		ret = tcf_idr_create(tn, parm->index, est, a,
131 				     &act_skbedit_ops, bind, false);
132 		if (ret)
133 			return ret;
134 
135 		d = to_skbedit(*a);
136 		ret = ACT_P_CREATED;
137 	} else {
138 		d = to_skbedit(*a);
139 		tcf_idr_release(*a, bind);
140 		if (!ovr)
141 			return -EEXIST;
142 	}
143 
144 	spin_lock_bh(&d->tcf_lock);
145 
146 	d->flags = flags;
147 	if (flags & SKBEDIT_F_PRIORITY)
148 		d->priority = *priority;
149 	if (flags & SKBEDIT_F_QUEUE_MAPPING)
150 		d->queue_mapping = *queue_mapping;
151 	if (flags & SKBEDIT_F_MARK)
152 		d->mark = *mark;
153 	if (flags & SKBEDIT_F_PTYPE)
154 		d->ptype = *ptype;
155 	/* default behaviour is to use all the bits */
156 	d->mask = 0xffffffff;
157 	if (flags & SKBEDIT_F_MASK)
158 		d->mask = *mask;
159 
160 	d->tcf_action = parm->action;
161 
162 	spin_unlock_bh(&d->tcf_lock);
163 
164 	if (ret == ACT_P_CREATED)
165 		tcf_idr_insert(tn, *a);
166 	return ret;
167 }
168 
169 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
170 			    int bind, int ref)
171 {
172 	unsigned char *b = skb_tail_pointer(skb);
173 	struct tcf_skbedit *d = to_skbedit(a);
174 	struct tc_skbedit opt = {
175 		.index   = d->tcf_index,
176 		.refcnt  = d->tcf_refcnt - ref,
177 		.bindcnt = d->tcf_bindcnt - bind,
178 		.action  = d->tcf_action,
179 	};
180 	struct tcf_t t;
181 
182 	if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
183 		goto nla_put_failure;
184 	if ((d->flags & SKBEDIT_F_PRIORITY) &&
185 	    nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, d->priority))
186 		goto nla_put_failure;
187 	if ((d->flags & SKBEDIT_F_QUEUE_MAPPING) &&
188 	    nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, d->queue_mapping))
189 		goto nla_put_failure;
190 	if ((d->flags & SKBEDIT_F_MARK) &&
191 	    nla_put_u32(skb, TCA_SKBEDIT_MARK, d->mark))
192 		goto nla_put_failure;
193 	if ((d->flags & SKBEDIT_F_PTYPE) &&
194 	    nla_put_u16(skb, TCA_SKBEDIT_PTYPE, d->ptype))
195 		goto nla_put_failure;
196 	if ((d->flags & SKBEDIT_F_MASK) &&
197 	    nla_put_u32(skb, TCA_SKBEDIT_MASK, d->mask))
198 		goto nla_put_failure;
199 
200 	tcf_tm_dump(&t, &d->tcf_tm);
201 	if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
202 		goto nla_put_failure;
203 	return skb->len;
204 
205 nla_put_failure:
206 	nlmsg_trim(skb, b);
207 	return -1;
208 }
209 
210 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
211 			      struct netlink_callback *cb, int type,
212 			      const struct tc_action_ops *ops,
213 			      struct netlink_ext_ack *extack)
214 {
215 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
216 
217 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
218 }
219 
220 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index,
221 			      struct netlink_ext_ack *extack)
222 {
223 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
224 
225 	return tcf_idr_search(tn, a, index);
226 }
227 
228 static struct tc_action_ops act_skbedit_ops = {
229 	.kind		=	"skbedit",
230 	.type		=	TCA_ACT_SKBEDIT,
231 	.owner		=	THIS_MODULE,
232 	.act		=	tcf_skbedit,
233 	.dump		=	tcf_skbedit_dump,
234 	.init		=	tcf_skbedit_init,
235 	.walk		=	tcf_skbedit_walker,
236 	.lookup		=	tcf_skbedit_search,
237 	.size		=	sizeof(struct tcf_skbedit),
238 };
239 
240 static __net_init int skbedit_init_net(struct net *net)
241 {
242 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
243 
244 	return tc_action_net_init(tn, &act_skbedit_ops);
245 }
246 
247 static void __net_exit skbedit_exit_net(struct list_head *net_list)
248 {
249 	tc_action_net_exit(net_list, skbedit_net_id);
250 }
251 
252 static struct pernet_operations skbedit_net_ops = {
253 	.init = skbedit_init_net,
254 	.exit_batch = skbedit_exit_net,
255 	.id   = &skbedit_net_id,
256 	.size = sizeof(struct tc_action_net),
257 };
258 
259 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
260 MODULE_DESCRIPTION("SKB Editing");
261 MODULE_LICENSE("GPL");
262 
263 static int __init skbedit_init_module(void)
264 {
265 	return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
266 }
267 
268 static void __exit skbedit_cleanup_module(void)
269 {
270 	tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
271 }
272 
273 module_init(skbedit_init_module);
274 module_exit(skbedit_cleanup_module);
275