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
22 static struct tc_action_ops act_simp_ops;
23
24 #define SIMP_MAX_DATA 32
25 TC_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
46 static void tcf_simp_release(struct tc_action *a)
47 {
48 struct tcf_defact *d = to_defact(a);
49 kfree(d->tcfd_defdata);
50 }
51
52 static 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
61 static 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 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
76 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
77 spin_unlock_bh(&d->tcf_lock);
78 if (goto_ch)
79 tcf_chain_put_by_act(goto_ch);
80 return 0;
81 }
82
83 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
84 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
85 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
86 };
87
88 static int tcf_simp_init(struct net *net, struct nlattr *nla,
89 struct nlattr *est, struct tc_action **a,
90 struct tcf_proto *tp, u32 flags,
91 struct netlink_ext_ack *extack)
92 {
93 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
94 bool bind = flags & TCA_ACT_FLAGS_BIND;
95 struct nlattr *tb[TCA_DEF_MAX + 1];
96 struct tcf_chain *goto_ch = NULL;
97 struct tc_defact *parm;
98 struct tcf_defact *d;
99 bool exists = false;
100 int ret = 0, err;
101 u32 index;
102
103 if (nla == NULL)
104 return -EINVAL;
105
106 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy,
107 NULL);
108 if (err < 0)
109 return err;
110
111 if (tb[TCA_DEF_PARMS] == NULL)
112 return -EINVAL;
113
114 parm = nla_data(tb[TCA_DEF_PARMS]);
115 index = parm->index;
116 err = tcf_idr_check_alloc(tn, &index, a, bind);
117 if (err < 0)
118 return err;
119 exists = err;
120 if (exists && bind)
121 return ACT_P_BOUND;
122
123 if (tb[TCA_DEF_DATA] == NULL) {
124 if (exists)
125 tcf_idr_release(*a, bind);
126 else
127 tcf_idr_cleanup(tn, index);
128 return -EINVAL;
129 }
130
131 if (!exists) {
132 ret = tcf_idr_create(tn, index, est, a,
133 &act_simp_ops, bind, false, flags);
134 if (ret) {
135 tcf_idr_cleanup(tn, index);
136 return ret;
137 }
138
139 d = to_defact(*a);
140 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
141 extack);
142 if (err < 0)
143 goto release_idr;
144
145 err = alloc_defdata(d, tb[TCA_DEF_DATA]);
146 if (err < 0)
147 goto put_chain;
148
149 tcf_action_set_ctrlact(*a, parm->action, goto_ch);
150 ret = ACT_P_CREATED;
151 } else {
152 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
153 err = -EEXIST;
154 goto release_idr;
155 }
156
157 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack);
158 if (err)
159 goto release_idr;
160 }
161
162 return ret;
163 put_chain:
164 if (goto_ch)
165 tcf_chain_put_by_act(goto_ch);
166 release_idr:
167 tcf_idr_release(*a, bind);
168 return err;
169 }
170
171 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
172 int bind, int ref)
173 {
174 unsigned char *b = skb_tail_pointer(skb);
175 struct tcf_defact *d = to_defact(a);
176 struct tc_defact opt = {
177 .index = d->tcf_index,
178 .refcnt = refcount_read(&d->tcf_refcnt) - ref,
179 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
180 };
181 struct tcf_t t;
182
183 spin_lock_bh(&d->tcf_lock);
184 opt.action = d->tcf_action;
185 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
186 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
187 goto nla_put_failure;
188
189 tcf_tm_dump(&t, &d->tcf_tm);
190 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
191 goto nla_put_failure;
192 spin_unlock_bh(&d->tcf_lock);
193
194 return skb->len;
195
196 nla_put_failure:
197 spin_unlock_bh(&d->tcf_lock);
198 nlmsg_trim(skb, b);
199 return -1;
200 }
201
202 static struct tc_action_ops act_simp_ops = {
203 .kind = "simple",
204 .id = TCA_ID_SIMP,
205 .owner = THIS_MODULE,
206 .act = tcf_simp_act,
207 .dump = tcf_simp_dump,
208 .cleanup = tcf_simp_release,
209 .init = tcf_simp_init,
210 .size = sizeof(struct tcf_defact),
211 };
212 MODULE_ALIAS_NET_ACT("simple");
213
214 static __net_init int simp_init_net(struct net *net)
215 {
216 struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
217
218 return tc_action_net_init(net, tn, &act_simp_ops);
219 }
220
221 static void __net_exit simp_exit_net(struct list_head *net_list)
222 {
223 tc_action_net_exit(net_list, act_simp_ops.net_id);
224 }
225
226 static struct pernet_operations simp_net_ops = {
227 .init = simp_init_net,
228 .exit_batch = simp_exit_net,
229 .id = &act_simp_ops.net_id,
230 .size = sizeof(struct tc_action_net),
231 };
232
233 MODULE_AUTHOR("Jamal Hadi Salim(2005)");
234 MODULE_DESCRIPTION("Simple example action");
235 MODULE_LICENSE("GPL");
236
237 static int __init simp_init_module(void)
238 {
239 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
240 if (!ret)
241 pr_info("Simple TC action Loaded\n");
242 return ret;
243 }
244
245 static void __exit simp_cleanup_module(void)
246 {
247 tcf_unregister_action(&act_simp_ops, &simp_net_ops);
248 }
249
250 module_init(simp_init_module);
251 module_exit(simp_cleanup_module);
252
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