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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/act_simple.c Simple example of an action
4 *
5 * Authors: Jamal Hadi Salim (2005-8)
6 */
7
8#include <linux/module.h>
9#include <linux/slab.h>
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/skbuff.h>
13#include <linux/rtnetlink.h>
14#include <net/netlink.h>
15#include <net/pkt_sched.h>
16#include <net/pkt_cls.h>
17#include <net/tc_wrapper.h>
18
19#include <linux/tc_act/tc_defact.h>
20#include <net/tc_act/tc_defact.h>
21
22static struct tc_action_ops act_simp_ops;
23
24#define SIMP_MAX_DATA 32
25TC_INDIRECT_SCOPE int tcf_simp_act(struct sk_buff *skb,
26 const struct tc_action *a,
27 struct tcf_result *res)
28{
29 struct tcf_defact *d = to_defact(a);
30
31 spin_lock(&d->tcf_lock);
32 tcf_lastuse_update(&d->tcf_tm);
33 bstats_update(&d->tcf_bstats, skb);
34
35 /* print policy string followed by _ then packet count
36 * Example if this was the 3rd packet and the string was "hello"
37 * then it would look like "hello_3" (without quotes)
38 */
39 pr_info("simple: %s_%llu\n",
40 (char *)d->tcfd_defdata,
41 u64_stats_read(&d->tcf_bstats.packets));
42 spin_unlock(&d->tcf_lock);
43 return d->tcf_action;
44}
45
46static void tcf_simp_release(struct tc_action *a)
47{
48 struct tcf_defact *d = to_defact(a);
49 kfree(d->tcfd_defdata);
50}
51
52static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata)
53{
54 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
55 if (unlikely(!d->tcfd_defdata))
56 return -ENOMEM;
57 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
58 return 0;
59}
60
61static int reset_policy(struct tc_action *a, const struct nlattr *defdata,
62 struct tc_defact *p, struct tcf_proto *tp,
63 struct netlink_ext_ack *extack)
64{
65 struct tcf_chain *goto_ch = NULL;
66 struct tcf_defact *d;
67 int err;
68
69 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack);
70 if (err < 0)
71 return err;
72 d = to_defact(a);
73 spin_lock_bh(&d->tcf_lock);
74 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch);
75 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
76 spin_unlock_bh(&d->tcf_lock);
77 if (goto_ch)
78 tcf_chain_put_by_act(goto_ch);
79 return 0;
80}
81
82static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
83 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
84 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
85};
86
87static int tcf_simp_init(struct net *net, struct nlattr *nla,
88 struct nlattr *est, struct tc_action **a,
89 struct tcf_proto *tp, u32 flags,
90 struct netlink_ext_ack *extack)
91{
92 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
93 bool bind = flags & TCA_ACT_FLAGS_BIND;
94 struct nlattr *tb[TCA_DEF_MAX + 1];
95 struct tcf_chain *goto_ch = NULL;
96 struct tc_defact *parm;
97 struct tcf_defact *d;
98 bool exists = false;
99 int ret = 0, err;
100 u32 index;
101
102 if (nla == NULL)
103 return -EINVAL;
104
105 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy,
106 NULL);
107 if (err < 0)
108 return err;
109
110 if (tb[TCA_DEF_PARMS] == NULL)
111 return -EINVAL;
112
113 parm = nla_data(tb[TCA_DEF_PARMS]);
114 index = parm->index;
115 err = tcf_idr_check_alloc(tn, &index, a, bind);
116 if (err < 0)
117 return err;
118 exists = err;
119 if (exists && bind)
120 return ACT_P_BOUND;
121
122 if (tb[TCA_DEF_DATA] == NULL) {
123 if (exists)
124 tcf_idr_release(*a, bind);
125 else
126 tcf_idr_cleanup(tn, index);
127 return -EINVAL;
128 }
129
130 if (!exists) {
131 ret = tcf_idr_create(tn, index, est, a,
132 &act_simp_ops, bind, false, flags);
133 if (ret) {
134 tcf_idr_cleanup(tn, index);
135 return ret;
136 }
137
138 d = to_defact(*a);
139 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
140 extack);
141 if (err < 0)
142 goto release_idr;
143
144 err = alloc_defdata(d, tb[TCA_DEF_DATA]);
145 if (err < 0)
146 goto put_chain;
147
148 tcf_action_set_ctrlact(*a, parm->action, goto_ch);
149 ret = ACT_P_CREATED;
150 } else {
151 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
152 err = -EEXIST;
153 goto release_idr;
154 }
155
156 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack);
157 if (err)
158 goto release_idr;
159 }
160
161 return ret;
162put_chain:
163 if (goto_ch)
164 tcf_chain_put_by_act(goto_ch);
165release_idr:
166 tcf_idr_release(*a, bind);
167 return err;
168}
169
170static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
171 int bind, int ref)
172{
173 unsigned char *b = skb_tail_pointer(skb);
174 struct tcf_defact *d = to_defact(a);
175 struct tc_defact opt = {
176 .index = d->tcf_index,
177 .refcnt = refcount_read(&d->tcf_refcnt) - ref,
178 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
179 };
180 struct tcf_t t;
181
182 spin_lock_bh(&d->tcf_lock);
183 opt.action = d->tcf_action;
184 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
185 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
186 goto nla_put_failure;
187
188 tcf_tm_dump(&t, &d->tcf_tm);
189 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
190 goto nla_put_failure;
191 spin_unlock_bh(&d->tcf_lock);
192
193 return skb->len;
194
195nla_put_failure:
196 spin_unlock_bh(&d->tcf_lock);
197 nlmsg_trim(skb, b);
198 return -1;
199}
200
201static struct tc_action_ops act_simp_ops = {
202 .kind = "simple",
203 .id = TCA_ID_SIMP,
204 .owner = THIS_MODULE,
205 .act = tcf_simp_act,
206 .dump = tcf_simp_dump,
207 .cleanup = tcf_simp_release,
208 .init = tcf_simp_init,
209 .size = sizeof(struct tcf_defact),
210};
211MODULE_ALIAS_NET_ACT("simple");
212
213static __net_init int simp_init_net(struct net *net)
214{
215 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
216
217 return tc_action_net_init(net, tn, &act_simp_ops);
218}
219
220static void __net_exit simp_exit_net(struct list_head *net_list)
221{
222 tc_action_net_exit(net_list, act_simp_ops.net_id);
223}
224
225static struct pernet_operations simp_net_ops = {
226 .init = simp_init_net,
227 .exit_batch = simp_exit_net,
228 .id = &act_simp_ops.net_id,
229 .size = sizeof(struct tc_action_net),
230};
231
232MODULE_AUTHOR("Jamal Hadi Salim(2005)");
233MODULE_DESCRIPTION("Simple example action");
234MODULE_LICENSE("GPL");
235
236static int __init simp_init_module(void)
237{
238 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
239 if (!ret)
240 pr_info("Simple TC action Loaded\n");
241 return ret;
242}
243
244static void __exit simp_cleanup_module(void)
245{
246 tcf_unregister_action(&act_simp_ops, &simp_net_ops);
247}
248
249module_init(simp_init_module);
250module_exit(simp_cleanup_module);