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
18 #include <linux/tc_act/tc_defact.h>
19 #include <net/tc_act/tc_defact.h>
20
21 static unsigned int simp_net_id;
22 static struct tc_action_ops act_simp_ops;
23
24 #define SIMP_MAX_DATA 32
tcf_simp_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)25 static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a,
26 struct tcf_result *res)
27 {
28 struct tcf_defact *d = to_defact(a);
29
30 spin_lock(&d->tcf_lock);
31 tcf_lastuse_update(&d->tcf_tm);
32 bstats_update(&d->tcf_bstats, skb);
33
34 /* print policy string followed by _ then packet count
35 * Example if this was the 3rd packet and the string was "hello"
36 * then it would look like "hello_3" (without quotes)
37 */
38 pr_info("simple: %s_%llu\n",
39 (char *)d->tcfd_defdata, d->tcf_bstats.packets);
40 spin_unlock(&d->tcf_lock);
41 return d->tcf_action;
42 }
43
tcf_simp_release(struct tc_action * a)44 static void tcf_simp_release(struct tc_action *a)
45 {
46 struct tcf_defact *d = to_defact(a);
47 kfree(d->tcfd_defdata);
48 }
49
alloc_defdata(struct tcf_defact * d,const struct nlattr * defdata)50 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata)
51 {
52 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
53 if (unlikely(!d->tcfd_defdata))
54 return -ENOMEM;
55 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
56 return 0;
57 }
58
reset_policy(struct tc_action * a,const struct nlattr * defdata,struct tc_defact * p,struct tcf_proto * tp,struct netlink_ext_ack * extack)59 static int reset_policy(struct tc_action *a, const struct nlattr *defdata,
60 struct tc_defact *p, struct tcf_proto *tp,
61 struct netlink_ext_ack *extack)
62 {
63 struct tcf_chain *goto_ch = NULL;
64 struct tcf_defact *d;
65 int err;
66
67 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack);
68 if (err < 0)
69 return err;
70 d = to_defact(a);
71 spin_lock_bh(&d->tcf_lock);
72 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch);
73 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
74 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
75 spin_unlock_bh(&d->tcf_lock);
76 if (goto_ch)
77 tcf_chain_put_by_act(goto_ch);
78 return 0;
79 }
80
81 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
82 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
83 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
84 };
85
tcf_simp_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,int ovr,int bind,bool rtnl_held,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)86 static int tcf_simp_init(struct net *net, struct nlattr *nla,
87 struct nlattr *est, struct tc_action **a,
88 int ovr, int bind, bool rtnl_held,
89 struct tcf_proto *tp, u32 flags,
90 struct netlink_ext_ack *extack)
91 {
92 struct tc_action_net *tn = net_generic(net, simp_net_id);
93 struct nlattr *tb[TCA_DEF_MAX + 1];
94 struct tcf_chain *goto_ch = NULL;
95 struct tc_defact *parm;
96 struct tcf_defact *d;
97 bool exists = false;
98 int ret = 0, err;
99 u32 index;
100
101 if (nla == NULL)
102 return -EINVAL;
103
104 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy,
105 NULL);
106 if (err < 0)
107 return err;
108
109 if (tb[TCA_DEF_PARMS] == NULL)
110 return -EINVAL;
111
112 parm = nla_data(tb[TCA_DEF_PARMS]);
113 index = parm->index;
114 err = tcf_idr_check_alloc(tn, &index, a, bind);
115 if (err < 0)
116 return err;
117 exists = err;
118 if (exists && bind)
119 return 0;
120
121 if (tb[TCA_DEF_DATA] == NULL) {
122 if (exists)
123 tcf_idr_release(*a, bind);
124 else
125 tcf_idr_cleanup(tn, index);
126 return -EINVAL;
127 }
128
129 if (!exists) {
130 ret = tcf_idr_create(tn, index, est, a,
131 &act_simp_ops, bind, false, 0);
132 if (ret) {
133 tcf_idr_cleanup(tn, index);
134 return ret;
135 }
136
137 d = to_defact(*a);
138 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
139 extack);
140 if (err < 0)
141 goto release_idr;
142
143 err = alloc_defdata(d, tb[TCA_DEF_DATA]);
144 if (err < 0)
145 goto put_chain;
146
147 tcf_action_set_ctrlact(*a, parm->action, goto_ch);
148 ret = ACT_P_CREATED;
149 } else {
150 if (!ovr) {
151 err = -EEXIST;
152 goto release_idr;
153 }
154
155 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack);
156 if (err)
157 goto release_idr;
158 }
159
160 return ret;
161 put_chain:
162 if (goto_ch)
163 tcf_chain_put_by_act(goto_ch);
164 release_idr:
165 tcf_idr_release(*a, bind);
166 return err;
167 }
168
tcf_simp_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)169 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
170 int bind, int ref)
171 {
172 unsigned char *b = skb_tail_pointer(skb);
173 struct tcf_defact *d = to_defact(a);
174 struct tc_defact opt = {
175 .index = d->tcf_index,
176 .refcnt = refcount_read(&d->tcf_refcnt) - ref,
177 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
178 };
179 struct tcf_t t;
180
181 spin_lock_bh(&d->tcf_lock);
182 opt.action = d->tcf_action;
183 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
184 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
185 goto nla_put_failure;
186
187 tcf_tm_dump(&t, &d->tcf_tm);
188 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
189 goto nla_put_failure;
190 spin_unlock_bh(&d->tcf_lock);
191
192 return skb->len;
193
194 nla_put_failure:
195 spin_unlock_bh(&d->tcf_lock);
196 nlmsg_trim(skb, b);
197 return -1;
198 }
199
tcf_simp_walker(struct net * net,struct sk_buff * skb,struct netlink_callback * cb,int type,const struct tc_action_ops * ops,struct netlink_ext_ack * extack)200 static int tcf_simp_walker(struct net *net, struct sk_buff *skb,
201 struct netlink_callback *cb, int type,
202 const struct tc_action_ops *ops,
203 struct netlink_ext_ack *extack)
204 {
205 struct tc_action_net *tn = net_generic(net, simp_net_id);
206
207 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
208 }
209
tcf_simp_search(struct net * net,struct tc_action ** a,u32 index)210 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index)
211 {
212 struct tc_action_net *tn = net_generic(net, simp_net_id);
213
214 return tcf_idr_search(tn, a, index);
215 }
216
217 static struct tc_action_ops act_simp_ops = {
218 .kind = "simple",
219 .id = TCA_ID_SIMP,
220 .owner = THIS_MODULE,
221 .act = tcf_simp_act,
222 .dump = tcf_simp_dump,
223 .cleanup = tcf_simp_release,
224 .init = tcf_simp_init,
225 .walk = tcf_simp_walker,
226 .lookup = tcf_simp_search,
227 .size = sizeof(struct tcf_defact),
228 };
229
simp_init_net(struct net * net)230 static __net_init int simp_init_net(struct net *net)
231 {
232 struct tc_action_net *tn = net_generic(net, simp_net_id);
233
234 return tc_action_net_init(net, tn, &act_simp_ops);
235 }
236
simp_exit_net(struct list_head * net_list)237 static void __net_exit simp_exit_net(struct list_head *net_list)
238 {
239 tc_action_net_exit(net_list, simp_net_id);
240 }
241
242 static struct pernet_operations simp_net_ops = {
243 .init = simp_init_net,
244 .exit_batch = simp_exit_net,
245 .id = &simp_net_id,
246 .size = sizeof(struct tc_action_net),
247 };
248
249 MODULE_AUTHOR("Jamal Hadi Salim(2005)");
250 MODULE_DESCRIPTION("Simple example action");
251 MODULE_LICENSE("GPL");
252
simp_init_module(void)253 static int __init simp_init_module(void)
254 {
255 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
256 if (!ret)
257 pr_info("Simple TC action Loaded\n");
258 return ret;
259 }
260
simp_cleanup_module(void)261 static void __exit simp_cleanup_module(void)
262 {
263 tcf_unregister_action(&act_simp_ops, &simp_net_ops);
264 }
265
266 module_init(simp_init_module);
267 module_exit(simp_cleanup_module);
268