2 * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us>
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.
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>
19 #include <linux/tc_act/tc_bpf.h>
20 #include <net/tc_act/tc_bpf.h>
22 #define BPF_TAB_MASK 15
24 static int tcf_bpf(struct sk_buff *skb, const struct tc_action *a,
25 struct tcf_result *res)
27 struct tcf_bpf *b = a->priv;
31 spin_lock(&b->tcf_lock);
32 b->tcf_tm.lastuse = jiffies;
33 bstats_update(&b->tcf_bstats, skb);
34 action = b->tcf_action;
36 filter_res = BPF_PROG_RUN(b->filter, skb);
37 if (filter_res == 0) {
38 /* Return code 0 from the BPF program
39 * is being interpreted as a drop here.
42 b->tcf_qstats.drops++;
45 spin_unlock(&b->tcf_lock);
49 static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *a,
52 unsigned char *tp = skb_tail_pointer(skb);
53 struct tcf_bpf *b = a->priv;
54 struct tc_act_bpf opt = {
55 .index = b->tcf_index,
56 .refcnt = b->tcf_refcnt - ref,
57 .bindcnt = b->tcf_bindcnt - bind,
58 .action = b->tcf_action,
63 if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
66 if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, b->bpf_num_ops))
69 nla = nla_reserve(skb, TCA_ACT_BPF_OPS, b->bpf_num_ops *
70 sizeof(struct sock_filter));
74 memcpy(nla_data(nla), b->bpf_ops, nla_len(nla));
76 t.install = jiffies_to_clock_t(jiffies - b->tcf_tm.install);
77 t.lastuse = jiffies_to_clock_t(jiffies - b->tcf_tm.lastuse);
78 t.expires = jiffies_to_clock_t(b->tcf_tm.expires);
79 if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(t), &t))
88 static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
89 [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) },
90 [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 },
91 [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY,
92 .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
95 static int tcf_bpf_init(struct net *net, struct nlattr *nla,
96 struct nlattr *est, struct tc_action *a,
99 struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
100 struct tc_act_bpf *parm;
102 u16 bpf_size, bpf_num_ops;
103 struct sock_filter *bpf_ops;
104 struct sock_fprog_kern tmp;
111 ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy);
115 if (!tb[TCA_ACT_BPF_PARMS] ||
116 !tb[TCA_ACT_BPF_OPS_LEN] || !tb[TCA_ACT_BPF_OPS])
118 parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
120 bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
121 if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
124 bpf_size = bpf_num_ops * sizeof(*bpf_ops);
125 if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
128 bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
132 memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
134 tmp.len = bpf_num_ops;
135 tmp.filter = bpf_ops;
137 ret = bpf_prog_create(&fp, &tmp);
141 if (!tcf_hash_check(parm->index, a, bind)) {
142 ret = tcf_hash_create(parm->index, est, a, sizeof(*b), bind);
150 tcf_hash_release(a, bind);
158 spin_lock_bh(&b->tcf_lock);
159 b->tcf_action = parm->action;
160 b->bpf_num_ops = bpf_num_ops;
161 b->bpf_ops = bpf_ops;
163 spin_unlock_bh(&b->tcf_lock);
165 if (ret == ACT_P_CREATED)
170 bpf_prog_destroy(fp);
176 static void tcf_bpf_cleanup(struct tc_action *a, int bind)
178 struct tcf_bpf *b = a->priv;
180 bpf_prog_destroy(b->filter);
183 static struct tc_action_ops act_bpf_ops = {
186 .owner = THIS_MODULE,
188 .dump = tcf_bpf_dump,
189 .cleanup = tcf_bpf_cleanup,
190 .init = tcf_bpf_init,
193 static int __init bpf_init_module(void)
195 return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK);
198 static void __exit bpf_cleanup_module(void)
200 tcf_unregister_action(&act_bpf_ops);
203 module_init(bpf_init_module);
204 module_exit(bpf_cleanup_module);
206 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
207 MODULE_DESCRIPTION("TC BPF based action");
208 MODULE_LICENSE("GPL v2");