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(lock: &d->tcf_lock); |
32 | tcf_lastuse_update(tm: &d->tcf_tm); |
33 | bstats_update(bstats: &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(lock: &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(objp: 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(dst: d->tcfd_defdata, nla: 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(action: p->action, tp, handle: &goto_ch, newchain: extack); |
70 | if (err < 0) |
71 | return err; |
72 | d = to_defact(a); |
73 | spin_lock_bh(lock: &d->tcf_lock); |
74 | goto_ch = tcf_action_set_ctrlact(a, action: p->action, newchain: goto_ch); |
75 | memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); |
76 | nla_strscpy(dst: d->tcfd_defdata, nla: defdata, SIMP_MAX_DATA); |
77 | spin_unlock_bh(lock: &d->tcf_lock); |
78 | if (goto_ch) |
79 | tcf_chain_put_by_act(chain: 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, id: 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, policy: 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(nla: tb[TCA_DEF_PARMS]); |
115 | index = parm->index; |
116 | err = tcf_idr_check_alloc(tn, index: &index, a, bind); |
117 | if (err < 0) |
118 | return err; |
119 | exists = err; |
120 | if (exists && bind) |
121 | return 0; |
122 | |
123 | if (tb[TCA_DEF_DATA] == NULL) { |
124 | if (exists) |
125 | tcf_idr_release(a: *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 | ops: &act_simp_ops, bind, cpustats: 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(action: parm->action, tp, handle: &goto_ch, |
141 | newchain: extack); |
142 | if (err < 0) |
143 | goto release_idr; |
144 | |
145 | err = alloc_defdata(d, defdata: tb[TCA_DEF_DATA]); |
146 | if (err < 0) |
147 | goto put_chain; |
148 | |
149 | tcf_action_set_ctrlact(a: *a, action: parm->action, newchain: 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: *a, defdata: tb[TCA_DEF_DATA], p: 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(chain: goto_ch); |
166 | release_idr: |
167 | tcf_idr_release(a: *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(r: &d->tcf_refcnt) - ref, |
179 | .bindcnt = atomic_read(v: &d->tcf_bindcnt) - bind, |
180 | }; |
181 | struct tcf_t t; |
182 | |
183 | spin_lock_bh(lock: &d->tcf_lock); |
184 | opt.action = d->tcf_action; |
185 | if (nla_put(skb, attrtype: TCA_DEF_PARMS, attrlen: sizeof(opt), data: &opt) || |
186 | nla_put_string(skb, attrtype: TCA_DEF_DATA, str: d->tcfd_defdata)) |
187 | goto nla_put_failure; |
188 | |
189 | tcf_tm_dump(dtm: &t, stm: &d->tcf_tm); |
190 | if (nla_put_64bit(skb, attrtype: TCA_DEF_TM, attrlen: sizeof(t), data: &t, padattr: TCA_DEF_PAD)) |
191 | goto nla_put_failure; |
192 | spin_unlock_bh(lock: &d->tcf_lock); |
193 | |
194 | return skb->len; |
195 | |
196 | nla_put_failure: |
197 | spin_unlock_bh(lock: &d->tcf_lock); |
198 | nlmsg_trim(skb, mark: 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 | |
213 | static __net_init int simp_init_net(struct net *net) |
214 | { |
215 | struct tc_action_net *tn = net_generic(net, id: act_simp_ops.net_id); |
216 | |
217 | return tc_action_net_init(net, tn, ops: &act_simp_ops); |
218 | } |
219 | |
220 | static void __net_exit simp_exit_net(struct list_head *net_list) |
221 | { |
222 | tc_action_net_exit(net_list, id: act_simp_ops.net_id); |
223 | } |
224 | |
225 | static 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 | |
232 | MODULE_AUTHOR("Jamal Hadi Salim(2005)" ); |
233 | MODULE_DESCRIPTION("Simple example action" ); |
234 | MODULE_LICENSE("GPL" ); |
235 | |
236 | static int __init simp_init_module(void) |
237 | { |
238 | int ret = tcf_register_action(a: &act_simp_ops, ops: &simp_net_ops); |
239 | if (!ret) |
240 | pr_info("Simple TC action Loaded\n" ); |
241 | return ret; |
242 | } |
243 | |
244 | static void __exit simp_cleanup_module(void) |
245 | { |
246 | tcf_unregister_action(a: &act_simp_ops, ops: &simp_net_ops); |
247 | } |
248 | |
249 | module_init(simp_init_module); |
250 | module_exit(simp_cleanup_module); |
251 | |