tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
21static unsigned int simp_net_id;
22static struct tc_action_ops act_simp_ops;
23
24#define SIMP_MAX_DATA 32
25static 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,
40 u64_stats_read(&d->tcf_bstats.packets));
41 spin_unlock(&d->tcf_lock);
42 return d->tcf_action;
43}
44
45static void tcf_simp_release(struct tc_action *a)
46{
47 struct tcf_defact *d = to_defact(a);
48 kfree(d->tcfd_defdata);
49}
50
51static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata)
52{
53 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
54 if (unlikely(!d->tcfd_defdata))
55 return -ENOMEM;
56 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
57 return 0;
58}
59
60static int reset_policy(struct tc_action *a, const struct nlattr *defdata,
61 struct tc_defact *p, struct tcf_proto *tp,
62 struct netlink_ext_ack *extack)
63{
64 struct tcf_chain *goto_ch = NULL;
65 struct tcf_defact *d;
66 int err;
67
68 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack);
69 if (err < 0)
70 return err;
71 d = to_defact(a);
72 spin_lock_bh(&d->tcf_lock);
73 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch);
74 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
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, simp_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 0;
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, 0);
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 int tcf_simp_walker(struct net *net, struct sk_buff *skb,
202 struct netlink_callback *cb, int type,
203 const struct tc_action_ops *ops,
204 struct netlink_ext_ack *extack)
205{
206 struct tc_action_net *tn = net_generic(net, simp_net_id);
207
208 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
209}
210
211static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index)
212{
213 struct tc_action_net *tn = net_generic(net, simp_net_id);
214
215 return tcf_idr_search(tn, a, index);
216}
217
218static struct tc_action_ops act_simp_ops = {
219 .kind = "simple",
220 .id = TCA_ID_SIMP,
221 .owner = THIS_MODULE,
222 .act = tcf_simp_act,
223 .dump = tcf_simp_dump,
224 .cleanup = tcf_simp_release,
225 .init = tcf_simp_init,
226 .walk = tcf_simp_walker,
227 .lookup = tcf_simp_search,
228 .size = sizeof(struct tcf_defact),
229};
230
231static __net_init int simp_init_net(struct net *net)
232{
233 struct tc_action_net *tn = net_generic(net, simp_net_id);
234
235 return tc_action_net_init(net, tn, &act_simp_ops);
236}
237
238static void __net_exit simp_exit_net(struct list_head *net_list)
239{
240 tc_action_net_exit(net_list, simp_net_id);
241}
242
243static struct pernet_operations simp_net_ops = {
244 .init = simp_init_net,
245 .exit_batch = simp_exit_net,
246 .id = &simp_net_id,
247 .size = sizeof(struct tc_action_net),
248};
249
250MODULE_AUTHOR("Jamal Hadi Salim(2005)");
251MODULE_DESCRIPTION("Simple example action");
252MODULE_LICENSE("GPL");
253
254static int __init simp_init_module(void)
255{
256 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
257 if (!ret)
258 pr_info("Simple TC action Loaded\n");
259 return ret;
260}
261
262static void __exit simp_cleanup_module(void)
263{
264 tcf_unregister_action(&act_simp_ops, &simp_net_ops);
265}
266
267module_init(simp_init_module);
268module_exit(simp_cleanup_module);