GNU Linux-libre 4.19.211-gnu1
[releases.git] / net / sched / act_skbedit.c
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 #include <net/ip.h>
27 #include <net/ipv6.h>
28 #include <net/dsfield.h>
29
30 #include <linux/tc_act/tc_skbedit.h>
31 #include <net/tc_act/tc_skbedit.h>
32
33 static unsigned int skbedit_net_id;
34 static struct tc_action_ops act_skbedit_ops;
35
36 static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a,
37                            struct tcf_result *res)
38 {
39         struct tcf_skbedit *d = to_skbedit(a);
40         struct tcf_skbedit_params *params;
41         int action;
42
43         tcf_lastuse_update(&d->tcf_tm);
44         bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
45
46         params = rcu_dereference_bh(d->params);
47         action = READ_ONCE(d->tcf_action);
48
49         if (params->flags & SKBEDIT_F_PRIORITY)
50                 skb->priority = params->priority;
51         if (params->flags & SKBEDIT_F_INHERITDSFIELD) {
52                 int wlen = skb_network_offset(skb);
53
54                 switch (skb_protocol(skb, true)) {
55                 case htons(ETH_P_IP):
56                         wlen += sizeof(struct iphdr);
57                         if (!pskb_may_pull(skb, wlen))
58                                 goto err;
59                         skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
60                         break;
61
62                 case htons(ETH_P_IPV6):
63                         wlen += sizeof(struct ipv6hdr);
64                         if (!pskb_may_pull(skb, wlen))
65                                 goto err;
66                         skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
67                         break;
68                 }
69         }
70         if (params->flags & SKBEDIT_F_QUEUE_MAPPING &&
71             skb->dev->real_num_tx_queues > params->queue_mapping)
72                 skb_set_queue_mapping(skb, params->queue_mapping);
73         if (params->flags & SKBEDIT_F_MARK) {
74                 skb->mark &= ~params->mask;
75                 skb->mark |= params->mark & params->mask;
76         }
77         if (params->flags & SKBEDIT_F_PTYPE)
78                 skb->pkt_type = params->ptype;
79         return action;
80
81 err:
82         qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats));
83         return TC_ACT_SHOT;
84 }
85
86 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
87         [TCA_SKBEDIT_PARMS]             = { .len = sizeof(struct tc_skbedit) },
88         [TCA_SKBEDIT_PRIORITY]          = { .len = sizeof(u32) },
89         [TCA_SKBEDIT_QUEUE_MAPPING]     = { .len = sizeof(u16) },
90         [TCA_SKBEDIT_MARK]              = { .len = sizeof(u32) },
91         [TCA_SKBEDIT_PTYPE]             = { .len = sizeof(u16) },
92         [TCA_SKBEDIT_MASK]              = { .len = sizeof(u32) },
93         [TCA_SKBEDIT_FLAGS]             = { .len = sizeof(u64) },
94 };
95
96 static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
97                             struct nlattr *est, struct tc_action **a,
98                             int ovr, int bind, bool rtnl_held,
99                             struct netlink_ext_ack *extack)
100 {
101         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
102         struct tcf_skbedit_params *params_old, *params_new;
103         struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
104         struct tc_skbedit *parm;
105         struct tcf_skbedit *d;
106         u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
107         u16 *queue_mapping = NULL, *ptype = NULL;
108         bool exists = false;
109         int ret = 0, err;
110         u32 index;
111
112         if (nla == NULL)
113                 return -EINVAL;
114
115         err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL);
116         if (err < 0)
117                 return err;
118
119         if (tb[TCA_SKBEDIT_PARMS] == NULL)
120                 return -EINVAL;
121
122         if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
123                 flags |= SKBEDIT_F_PRIORITY;
124                 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
125         }
126
127         if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
128                 flags |= SKBEDIT_F_QUEUE_MAPPING;
129                 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
130         }
131
132         if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
133                 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
134                 if (!skb_pkt_type_ok(*ptype))
135                         return -EINVAL;
136                 flags |= SKBEDIT_F_PTYPE;
137         }
138
139         if (tb[TCA_SKBEDIT_MARK] != NULL) {
140                 flags |= SKBEDIT_F_MARK;
141                 mark = nla_data(tb[TCA_SKBEDIT_MARK]);
142         }
143
144         if (tb[TCA_SKBEDIT_MASK] != NULL) {
145                 flags |= SKBEDIT_F_MASK;
146                 mask = nla_data(tb[TCA_SKBEDIT_MASK]);
147         }
148
149         if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
150                 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
151
152                 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
153                         flags |= SKBEDIT_F_INHERITDSFIELD;
154         }
155
156         parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
157         index = parm->index;
158         err = tcf_idr_check_alloc(tn, &index, a, bind);
159         if (err < 0)
160                 return err;
161         exists = err;
162         if (exists && bind)
163                 return 0;
164
165         if (!flags) {
166                 if (exists)
167                         tcf_idr_release(*a, bind);
168                 else
169                         tcf_idr_cleanup(tn, index);
170                 return -EINVAL;
171         }
172
173         if (!exists) {
174                 ret = tcf_idr_create(tn, index, est, a,
175                                      &act_skbedit_ops, bind, true);
176                 if (ret) {
177                         tcf_idr_cleanup(tn, index);
178                         return ret;
179                 }
180
181                 d = to_skbedit(*a);
182                 ret = ACT_P_CREATED;
183         } else {
184                 d = to_skbedit(*a);
185                 if (!ovr) {
186                         tcf_idr_release(*a, bind);
187                         return -EEXIST;
188                 }
189         }
190
191         ASSERT_RTNL();
192
193         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
194         if (unlikely(!params_new)) {
195                 tcf_idr_release(*a, bind);
196                 return -ENOMEM;
197         }
198
199         params_new->flags = flags;
200         if (flags & SKBEDIT_F_PRIORITY)
201                 params_new->priority = *priority;
202         if (flags & SKBEDIT_F_QUEUE_MAPPING)
203                 params_new->queue_mapping = *queue_mapping;
204         if (flags & SKBEDIT_F_MARK)
205                 params_new->mark = *mark;
206         if (flags & SKBEDIT_F_PTYPE)
207                 params_new->ptype = *ptype;
208         /* default behaviour is to use all the bits */
209         params_new->mask = 0xffffffff;
210         if (flags & SKBEDIT_F_MASK)
211                 params_new->mask = *mask;
212
213         d->tcf_action = parm->action;
214         params_old = rtnl_dereference(d->params);
215         rcu_assign_pointer(d->params, params_new);
216         if (params_old)
217                 kfree_rcu(params_old, rcu);
218
219         if (ret == ACT_P_CREATED)
220                 tcf_idr_insert(tn, *a);
221         return ret;
222 }
223
224 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
225                             int bind, int ref)
226 {
227         unsigned char *b = skb_tail_pointer(skb);
228         struct tcf_skbedit *d = to_skbedit(a);
229         struct tcf_skbedit_params *params;
230         struct tc_skbedit opt = {
231                 .index   = d->tcf_index,
232                 .refcnt  = refcount_read(&d->tcf_refcnt) - ref,
233                 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
234                 .action  = d->tcf_action,
235         };
236         u64 pure_flags = 0;
237         struct tcf_t t;
238
239         params = rtnl_dereference(d->params);
240
241         if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
242                 goto nla_put_failure;
243         if ((params->flags & SKBEDIT_F_PRIORITY) &&
244             nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority))
245                 goto nla_put_failure;
246         if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) &&
247             nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping))
248                 goto nla_put_failure;
249         if ((params->flags & SKBEDIT_F_MARK) &&
250             nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark))
251                 goto nla_put_failure;
252         if ((params->flags & SKBEDIT_F_PTYPE) &&
253             nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype))
254                 goto nla_put_failure;
255         if ((params->flags & SKBEDIT_F_MASK) &&
256             nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask))
257                 goto nla_put_failure;
258         if (params->flags & SKBEDIT_F_INHERITDSFIELD)
259                 pure_flags |= SKBEDIT_F_INHERITDSFIELD;
260         if (pure_flags != 0 &&
261             nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags))
262                 goto nla_put_failure;
263
264         tcf_tm_dump(&t, &d->tcf_tm);
265         if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
266                 goto nla_put_failure;
267         return skb->len;
268
269 nla_put_failure:
270         nlmsg_trim(skb, b);
271         return -1;
272 }
273
274 static void tcf_skbedit_cleanup(struct tc_action *a)
275 {
276         struct tcf_skbedit *d = to_skbedit(a);
277         struct tcf_skbedit_params *params;
278
279         params = rcu_dereference_protected(d->params, 1);
280         if (params)
281                 kfree_rcu(params, rcu);
282 }
283
284 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
285                               struct netlink_callback *cb, int type,
286                               const struct tc_action_ops *ops,
287                               struct netlink_ext_ack *extack)
288 {
289         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
290
291         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
292 }
293
294 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index,
295                               struct netlink_ext_ack *extack)
296 {
297         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
298
299         return tcf_idr_search(tn, a, index);
300 }
301
302 static struct tc_action_ops act_skbedit_ops = {
303         .kind           =       "skbedit",
304         .type           =       TCA_ACT_SKBEDIT,
305         .owner          =       THIS_MODULE,
306         .act            =       tcf_skbedit_act,
307         .dump           =       tcf_skbedit_dump,
308         .init           =       tcf_skbedit_init,
309         .cleanup        =       tcf_skbedit_cleanup,
310         .walk           =       tcf_skbedit_walker,
311         .lookup         =       tcf_skbedit_search,
312         .size           =       sizeof(struct tcf_skbedit),
313 };
314
315 static __net_init int skbedit_init_net(struct net *net)
316 {
317         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
318
319         return tc_action_net_init(net, tn, &act_skbedit_ops);
320 }
321
322 static void __net_exit skbedit_exit_net(struct list_head *net_list)
323 {
324         tc_action_net_exit(net_list, skbedit_net_id);
325 }
326
327 static struct pernet_operations skbedit_net_ops = {
328         .init = skbedit_init_net,
329         .exit_batch = skbedit_exit_net,
330         .id   = &skbedit_net_id,
331         .size = sizeof(struct tc_action_net),
332 };
333
334 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
335 MODULE_DESCRIPTION("SKB Editing");
336 MODULE_LICENSE("GPL");
337
338 static int __init skbedit_init_module(void)
339 {
340         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
341 }
342
343 static void __exit skbedit_cleanup_module(void)
344 {
345         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
346 }
347
348 module_init(skbedit_init_module);
349 module_exit(skbedit_cleanup_module);