blob: 5f6288fa3f1247462897cd747364dfbc9e0da843 [file] [log] [blame]
Jiri Pirkod23b8ad2015-01-15 09:52:39 +01001/*
2 * Copyright (c) 2015 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/filter.h>
16#include <net/netlink.h>
17#include <net/pkt_sched.h>
18
19#include <linux/tc_act/tc_bpf.h>
20#include <net/tc_act/tc_bpf.h>
21
22#define BPF_TAB_MASK 15
23
24static int tcf_bpf(struct sk_buff *skb, const struct tc_action *a,
25 struct tcf_result *res)
26{
27 struct tcf_bpf *b = a->priv;
Daniel Borkmannced585c2015-03-17 20:25:57 +010028 int action, filter_res;
Jiri Pirkod23b8ad2015-01-15 09:52:39 +010029
30 spin_lock(&b->tcf_lock);
Daniel Borkmannced585c2015-03-17 20:25:57 +010031
Jiri Pirkod23b8ad2015-01-15 09:52:39 +010032 b->tcf_tm.lastuse = jiffies;
33 bstats_update(&b->tcf_bstats, skb);
Jiri Pirkod23b8ad2015-01-15 09:52:39 +010034
35 filter_res = BPF_PROG_RUN(b->filter, skb);
Daniel Borkmannced585c2015-03-17 20:25:57 +010036
37 /* A BPF program may overwrite the default action opcode.
38 * Similarly as in cls_bpf, if filter_res == -1 we use the
39 * default action specified from tc.
40 *
41 * In case a different well-known TC_ACT opcode has been
42 * returned, it will overwrite the default one.
43 *
44 * For everything else that is unkown, TC_ACT_UNSPEC is
45 * returned.
46 */
47 switch (filter_res) {
48 case TC_ACT_PIPE:
49 case TC_ACT_RECLASSIFY:
50 case TC_ACT_OK:
51 action = filter_res;
52 break;
53 case TC_ACT_SHOT:
54 action = filter_res;
Jiri Pirkod23b8ad2015-01-15 09:52:39 +010055 b->tcf_qstats.drops++;
Daniel Borkmannced585c2015-03-17 20:25:57 +010056 break;
57 case TC_ACT_UNSPEC:
58 action = b->tcf_action;
59 break;
60 default:
61 action = TC_ACT_UNSPEC;
62 break;
Jiri Pirkod23b8ad2015-01-15 09:52:39 +010063 }
64
65 spin_unlock(&b->tcf_lock);
66 return action;
67}
68
69static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *a,
70 int bind, int ref)
71{
72 unsigned char *tp = skb_tail_pointer(skb);
73 struct tcf_bpf *b = a->priv;
74 struct tc_act_bpf opt = {
75 .index = b->tcf_index,
76 .refcnt = b->tcf_refcnt - ref,
77 .bindcnt = b->tcf_bindcnt - bind,
78 .action = b->tcf_action,
79 };
80 struct tcf_t t;
81 struct nlattr *nla;
82
83 if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
84 goto nla_put_failure;
85
86 if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, b->bpf_num_ops))
87 goto nla_put_failure;
88
89 nla = nla_reserve(skb, TCA_ACT_BPF_OPS, b->bpf_num_ops *
90 sizeof(struct sock_filter));
91 if (!nla)
92 goto nla_put_failure;
93
94 memcpy(nla_data(nla), b->bpf_ops, nla_len(nla));
95
96 t.install = jiffies_to_clock_t(jiffies - b->tcf_tm.install);
97 t.lastuse = jiffies_to_clock_t(jiffies - b->tcf_tm.lastuse);
98 t.expires = jiffies_to_clock_t(b->tcf_tm.expires);
99 if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(t), &t))
100 goto nla_put_failure;
101 return skb->len;
102
103nla_put_failure:
104 nlmsg_trim(skb, tp);
105 return -1;
106}
107
108static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
109 [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) },
110 [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 },
111 [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY,
112 .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
113};
114
115static int tcf_bpf_init(struct net *net, struct nlattr *nla,
116 struct nlattr *est, struct tc_action *a,
117 int ovr, int bind)
118{
119 struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
120 struct tc_act_bpf *parm;
121 struct tcf_bpf *b;
122 u16 bpf_size, bpf_num_ops;
123 struct sock_filter *bpf_ops;
124 struct sock_fprog_kern tmp;
125 struct bpf_prog *fp;
126 int ret;
127
128 if (!nla)
129 return -EINVAL;
130
131 ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy);
132 if (ret < 0)
133 return ret;
134
135 if (!tb[TCA_ACT_BPF_PARMS] ||
136 !tb[TCA_ACT_BPF_OPS_LEN] || !tb[TCA_ACT_BPF_OPS])
137 return -EINVAL;
138 parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
139
140 bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
141 if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
142 return -EINVAL;
143
144 bpf_size = bpf_num_ops * sizeof(*bpf_ops);
Daniel Borkmannfd3e6462015-01-22 10:58:19 +0100145 if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
146 return -EINVAL;
147
Jiri Pirkod23b8ad2015-01-15 09:52:39 +0100148 bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
149 if (!bpf_ops)
150 return -ENOMEM;
151
152 memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
153
154 tmp.len = bpf_num_ops;
155 tmp.filter = bpf_ops;
156
157 ret = bpf_prog_create(&fp, &tmp);
158 if (ret)
159 goto free_bpf_ops;
160
161 if (!tcf_hash_check(parm->index, a, bind)) {
162 ret = tcf_hash_create(parm->index, est, a, sizeof(*b), bind);
163 if (ret)
164 goto destroy_fp;
165
166 ret = ACT_P_CREATED;
167 } else {
168 if (bind)
169 goto destroy_fp;
170 tcf_hash_release(a, bind);
171 if (!ovr) {
172 ret = -EEXIST;
173 goto destroy_fp;
174 }
175 }
176
177 b = to_bpf(a);
178 spin_lock_bh(&b->tcf_lock);
179 b->tcf_action = parm->action;
180 b->bpf_num_ops = bpf_num_ops;
181 b->bpf_ops = bpf_ops;
182 b->filter = fp;
183 spin_unlock_bh(&b->tcf_lock);
184
185 if (ret == ACT_P_CREATED)
186 tcf_hash_insert(a);
187 return ret;
188
189destroy_fp:
190 bpf_prog_destroy(fp);
191free_bpf_ops:
192 kfree(bpf_ops);
193 return ret;
194}
195
196static void tcf_bpf_cleanup(struct tc_action *a, int bind)
197{
198 struct tcf_bpf *b = a->priv;
199
200 bpf_prog_destroy(b->filter);
201}
202
203static struct tc_action_ops act_bpf_ops = {
204 .kind = "bpf",
205 .type = TCA_ACT_BPF,
206 .owner = THIS_MODULE,
207 .act = tcf_bpf,
208 .dump = tcf_bpf_dump,
209 .cleanup = tcf_bpf_cleanup,
210 .init = tcf_bpf_init,
211};
212
213static int __init bpf_init_module(void)
214{
215 return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK);
216}
217
218static void __exit bpf_cleanup_module(void)
219{
220 tcf_unregister_action(&act_bpf_ops);
221}
222
223module_init(bpf_init_module);
224module_exit(bpf_cleanup_module);
225
226MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
227MODULE_DESCRIPTION("TC BPF based action");
228MODULE_LICENSE("GPL v2");