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-rw-r--r--net/sched/act_bpf.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
new file mode 100644
index 000000000000..82c5d7fc1988
--- /dev/null
+++ b/net/sched/act_bpf.c
@@ -0,0 +1,208 @@
1/*
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;
28 int action;
29 int filter_res;
30
31 spin_lock(&b->tcf_lock);
32 b->tcf_tm.lastuse = jiffies;
33 bstats_update(&b->tcf_bstats, skb);
34 action = b->tcf_action;
35
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.
40 */
41 action = TC_ACT_SHOT;
42 b->tcf_qstats.drops++;
43 }
44
45 spin_unlock(&b->tcf_lock);
46 return action;
47}
48
49static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *a,
50 int bind, int ref)
51{
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,
59 };
60 struct tcf_t t;
61 struct nlattr *nla;
62
63 if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
64 goto nla_put_failure;
65
66 if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, b->bpf_num_ops))
67 goto nla_put_failure;
68
69 nla = nla_reserve(skb, TCA_ACT_BPF_OPS, b->bpf_num_ops *
70 sizeof(struct sock_filter));
71 if (!nla)
72 goto nla_put_failure;
73
74 memcpy(nla_data(nla), b->bpf_ops, nla_len(nla));
75
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))
80 goto nla_put_failure;
81 return skb->len;
82
83nla_put_failure:
84 nlmsg_trim(skb, tp);
85 return -1;
86}
87
88static 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 },
93};
94
95static int tcf_bpf_init(struct net *net, struct nlattr *nla,
96 struct nlattr *est, struct tc_action *a,
97 int ovr, int bind)
98{
99 struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
100 struct tc_act_bpf *parm;
101 struct tcf_bpf *b;
102 u16 bpf_size, bpf_num_ops;
103 struct sock_filter *bpf_ops;
104 struct sock_fprog_kern tmp;
105 struct bpf_prog *fp;
106 int ret;
107
108 if (!nla)
109 return -EINVAL;
110
111 ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy);
112 if (ret < 0)
113 return ret;
114
115 if (!tb[TCA_ACT_BPF_PARMS] ||
116 !tb[TCA_ACT_BPF_OPS_LEN] || !tb[TCA_ACT_BPF_OPS])
117 return -EINVAL;
118 parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
119
120 bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
121 if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
122 return -EINVAL;
123
124 bpf_size = bpf_num_ops * sizeof(*bpf_ops);
125 if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
126 return -EINVAL;
127
128 bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
129 if (!bpf_ops)
130 return -ENOMEM;
131
132 memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
133
134 tmp.len = bpf_num_ops;
135 tmp.filter = bpf_ops;
136
137 ret = bpf_prog_create(&fp, &tmp);
138 if (ret)
139 goto free_bpf_ops;
140
141 if (!tcf_hash_check(parm->index, a, bind)) {
142 ret = tcf_hash_create(parm->index, est, a, sizeof(*b), bind);
143 if (ret)
144 goto destroy_fp;
145
146 ret = ACT_P_CREATED;
147 } else {
148 if (bind)
149 goto destroy_fp;
150 tcf_hash_release(a, bind);
151 if (!ovr) {
152 ret = -EEXIST;
153 goto destroy_fp;
154 }
155 }
156
157 b = to_bpf(a);
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;
162 b->filter = fp;
163 spin_unlock_bh(&b->tcf_lock);
164
165 if (ret == ACT_P_CREATED)
166 tcf_hash_insert(a);
167 return ret;
168
169destroy_fp:
170 bpf_prog_destroy(fp);
171free_bpf_ops:
172 kfree(bpf_ops);
173 return ret;
174}
175
176static void tcf_bpf_cleanup(struct tc_action *a, int bind)
177{
178 struct tcf_bpf *b = a->priv;
179
180 bpf_prog_destroy(b->filter);
181}
182
183static struct tc_action_ops act_bpf_ops = {
184 .kind = "bpf",
185 .type = TCA_ACT_BPF,
186 .owner = THIS_MODULE,
187 .act = tcf_bpf,
188 .dump = tcf_bpf_dump,
189 .cleanup = tcf_bpf_cleanup,
190 .init = tcf_bpf_init,
191};
192
193static int __init bpf_init_module(void)
194{
195 return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK);
196}
197
198static void __exit bpf_cleanup_module(void)
199{
200 tcf_unregister_action(&act_bpf_ops);
201}
202
203module_init(bpf_init_module);
204module_exit(bpf_cleanup_module);
205
206MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
207MODULE_DESCRIPTION("TC BPF based action");
208MODULE_LICENSE("GPL v2");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 08:49:30 -0500