1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/act_gact.c Generic actions
4 *
5 * copyright Jamal Hadi Salim (2002-4)
6 */
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/skbuff.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <net/netlink.h>
17 #include <net/pkt_sched.h>
18 #include <net/pkt_cls.h>
19 #include <linux/tc_act/tc_gact.h>
20 #include <net/tc_act/tc_gact.h>
21 #include <net/tc_wrapper.h>
22
23 static struct tc_action_ops act_gact_ops;
24
25 #ifdef CONFIG_GACT_PROB
26 static int gact_net_rand(struct tcf_gact *gact)
27 {
28 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
29 if (get_random_u32_below(gact->tcfg_pval))
30 return gact->tcf_action;
31 return gact->tcfg_paction;
32 }
33
34 static int gact_determ(struct tcf_gact *gact)
35 {
36 u32 pack = atomic_inc_return(&gact->packets);
37
38 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
39 if (pack % gact->tcfg_pval)
40 return gact->tcf_action;
41 return gact->tcfg_paction;
42 }
43
44 typedef int (*g_rand)(struct tcf_gact *gact);
45 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
46 #endif /* CONFIG_GACT_PROB */
47
48 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
49 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) },
50 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) },
51 };
52
53 static int tcf_gact_init(struct net *net, struct nlattr *nla,
54 struct nlattr *est, struct tc_action **a,
55 struct tcf_proto *tp, u32 flags,
56 struct netlink_ext_ack *extack)
57 {
58 struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
59 bool bind = flags & TCA_ACT_FLAGS_BIND;
60 struct nlattr *tb[TCA_GACT_MAX + 1];
61 struct tcf_chain *goto_ch = NULL;
62 struct tc_gact *parm;
63 struct tcf_gact *gact;
64 int ret = 0;
65 u32 index;
66 int err;
67 #ifdef CONFIG_GACT_PROB
68 struct tc_gact_p *p_parm = NULL;
69 #endif
70
71 if (nla == NULL)
72 return -EINVAL;
73
74 err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
75 NULL);
76 if (err < 0)
77 return err;
78
79 if (tb[TCA_GACT_PARMS] == NULL)
80 return -EINVAL;
81 parm = nla_data(tb[TCA_GACT_PARMS]);
82 index = parm->index;
83
84 #ifndef CONFIG_GACT_PROB
85 if (tb[TCA_GACT_PROB] != NULL)
86 return -EOPNOTSUPP;
87 #else
88 if (tb[TCA_GACT_PROB]) {
89 p_parm = nla_data(tb[TCA_GACT_PROB]);
90 if (p_parm->ptype >= MAX_RAND)
91 return -EINVAL;
92 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
93 NL_SET_ERR_MSG(extack,
94 "goto chain not allowed on fallback");
95 return -EINVAL;
96 }
97 }
98 #endif
99
100 err = tcf_idr_check_alloc(tn, &index, a, bind);
101 if (!err) {
102 ret = tcf_idr_create_from_flags(tn, index, est, a,
103 &act_gact_ops, bind, flags);
104 if (ret) {
105 tcf_idr_cleanup(tn, index);
106 return ret;
107 }
108 ret = ACT_P_CREATED;
109 } else if (err > 0) {
110 if (bind)/* dont override defaults */
111 return ACT_P_BOUND;
112 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
113 tcf_idr_release(*a, bind);
114 return -EEXIST;
115 }
116 } else {
117 return err;
118 }
119
120 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
121 if (err < 0)
122 goto release_idr;
123 gact = to_gact(*a);
124
125 spin_lock_bh(&gact->tcf_lock);
126 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
127 #ifdef CONFIG_GACT_PROB
128 if (p_parm) {
129 gact->tcfg_paction = p_parm->paction;
130 gact->tcfg_pval = max_t(u16, 1, p_parm->pval);
131 /* Make sure tcfg_pval is written before tcfg_ptype
132 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
133 */
134 smp_wmb();
135 gact->tcfg_ptype = p_parm->ptype;
136 }
137 #endif
138 spin_unlock_bh(&gact->tcf_lock);
139
140 if (goto_ch)
141 tcf_chain_put_by_act(goto_ch);
142
143 return ret;
144 release_idr:
145 tcf_idr_release(*a, bind);
146 return err;
147 }
148
149 TC_INDIRECT_SCOPE int tcf_gact_act(struct sk_buff *skb,
150 const struct tc_action *a,
151 struct tcf_result *res)
152 {
153 struct tcf_gact *gact = to_gact(a);
154 int action = READ_ONCE(gact->tcf_action);
155
156 #ifdef CONFIG_GACT_PROB
157 {
158 u32 ptype = READ_ONCE(gact->tcfg_ptype);
159
160 if (ptype)
161 action = gact_rand[ptype](gact);
162 }
163 #endif
164 tcf_action_update_bstats(&gact->common, skb);
165 if (action == TC_ACT_SHOT)
166 tcf_action_inc_drop_qstats(&gact->common);
167
168 tcf_lastuse_update(&gact->tcf_tm);
169
170 return action;
171 }
172
173 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
174 u64 drops, u64 lastuse, bool hw)
175 {
176 struct tcf_gact *gact = to_gact(a);
177 int action = READ_ONCE(gact->tcf_action);
178 struct tcf_t *tm = &gact->tcf_tm;
179
180 tcf_action_update_stats(a, bytes, packets,
181 action == TC_ACT_SHOT ? packets : drops, hw);
182 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
183 }
184
185 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
186 int bind, int ref)
187 {
188 unsigned char *b = skb_tail_pointer(skb);
189 struct tcf_gact *gact = to_gact(a);
190 struct tc_gact opt = {
191 .index = gact->tcf_index,
192 .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
193 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
194 };
195 struct tcf_t t;
196
197 spin_lock_bh(&gact->tcf_lock);
198 opt.action = gact->tcf_action;
199 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
200 goto nla_put_failure;
201 #ifdef CONFIG_GACT_PROB
202 if (gact->tcfg_ptype) {
203 struct tc_gact_p p_opt = {
204 .paction = gact->tcfg_paction,
205 .pval = gact->tcfg_pval,
206 .ptype = gact->tcfg_ptype,
207 };
208
209 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
210 goto nla_put_failure;
211 }
212 #endif
213 tcf_tm_dump(&t, &gact->tcf_tm);
214 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
215 goto nla_put_failure;
216 spin_unlock_bh(&gact->tcf_lock);
217
218 return skb->len;
219
220 nla_put_failure:
221 spin_unlock_bh(&gact->tcf_lock);
222 nlmsg_trim(skb, b);
223 return -1;
224 }
225
226 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
227 {
228 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
229
230 #ifdef CONFIG_GACT_PROB
231 if (to_gact(act)->tcfg_ptype)
232 /* TCA_GACT_PROB */
233 sz += nla_total_size(sizeof(struct tc_gact_p));
234 #endif
235
236 return sz;
237 }
238
239 static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
240 u32 *index_inc, bool bind,
241 struct netlink_ext_ack *extack)
242 {
243 if (bind) {
244 struct flow_action_entry *entry = entry_data;
245
246 if (is_tcf_gact_ok(act)) {
247 entry->id = FLOW_ACTION_ACCEPT;
248 } else if (is_tcf_gact_shot(act)) {
249 entry->id = FLOW_ACTION_DROP;
250 } else if (is_tcf_gact_trap(act)) {
251 entry->id = FLOW_ACTION_TRAP;
252 } else if (is_tcf_gact_goto_chain(act)) {
253 entry->id = FLOW_ACTION_GOTO;
254 entry->chain_index = tcf_gact_goto_chain_index(act);
255 } else if (is_tcf_gact_continue(act)) {
256 NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
257 return -EOPNOTSUPP;
258 } else if (is_tcf_gact_reclassify(act)) {
259 NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
260 return -EOPNOTSUPP;
261 } else if (is_tcf_gact_pipe(act)) {
262 NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
263 return -EOPNOTSUPP;
264 } else {
265 NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
266 return -EOPNOTSUPP;
267 }
268 *index_inc = 1;
269 } else {
270 struct flow_offload_action *fl_action = entry_data;
271
272 if (is_tcf_gact_ok(act))
273 fl_action->id = FLOW_ACTION_ACCEPT;
274 else if (is_tcf_gact_shot(act))
275 fl_action->id = FLOW_ACTION_DROP;
276 else if (is_tcf_gact_trap(act))
277 fl_action->id = FLOW_ACTION_TRAP;
278 else if (is_tcf_gact_goto_chain(act))
279 fl_action->id = FLOW_ACTION_GOTO;
280 else
281 return -EOPNOTSUPP;
282 }
283
284 return 0;
285 }
286
287 static struct tc_action_ops act_gact_ops = {
288 .kind = "gact",
289 .id = TCA_ID_GACT,
290 .owner = THIS_MODULE,
291 .act = tcf_gact_act,
292 .stats_update = tcf_gact_stats_update,
293 .dump = tcf_gact_dump,
294 .init = tcf_gact_init,
295 .get_fill_size = tcf_gact_get_fill_size,
296 .offload_act_setup = tcf_gact_offload_act_setup,
297 .size = sizeof(struct tcf_gact),
298 };
299 MODULE_ALIAS_NET_ACT("gact");
300
301 static __net_init int gact_init_net(struct net *net)
302 {
303 struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
304
305 return tc_action_net_init(net, tn, &act_gact_ops);
306 }
307
308 static void __net_exit gact_exit_net(struct list_head *net_list)
309 {
310 tc_action_net_exit(net_list, act_gact_ops.net_id);
311 }
312
313 static struct pernet_operations gact_net_ops = {
314 .init = gact_init_net,
315 .exit_batch = gact_exit_net,
316 .id = &act_gact_ops.net_id,
317 .size = sizeof(struct tc_action_net),
318 };
319
320 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
321 MODULE_DESCRIPTION("Generic Classifier actions");
322 MODULE_LICENSE("GPL");
323
324 static int __init gact_init_module(void)
325 {
326 #ifdef CONFIG_GACT_PROB
327 pr_info("GACT probability on\n");
328 #else
329 pr_info("GACT probability NOT on\n");
330 #endif
331
332 return tcf_register_action(&act_gact_ops, &gact_net_ops);
333 }
334
335 static void __exit gact_cleanup_module(void)
336 {
337 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
338 }
339
340 module_init(gact_init_module);
341 module_exit(gact_cleanup_module);
342
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