1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * net/sched/act_gact.c Generic actions
5 * copyright Jamal Hadi Salim (2002-4)
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>
22 static unsigned int gact_net_id;
23 static struct tc_action_ops act_gact_ops;
25 #ifdef CONFIG_GACT_PROB
26 static int gact_net_rand(struct tcf_gact *gact)
28 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
29 if (prandom_u32() % gact->tcfg_pval)
30 return gact->tcf_action;
31 return gact->tcfg_paction;
34 static int gact_determ(struct tcf_gact *gact)
36 u32 pack = atomic_inc_return(&gact->packets);
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;
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 */
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) },
53 static int tcf_gact_init(struct net *net, struct nlattr *nla,
54 struct nlattr *est, struct tc_action **a,
55 int ovr, int bind, bool rtnl_held,
56 struct tcf_proto *tp, struct netlink_ext_ack *extack)
58 struct tc_action_net *tn = net_generic(net, gact_net_id);
59 struct nlattr *tb[TCA_GACT_MAX + 1];
60 struct tcf_chain *goto_ch = NULL;
62 struct tcf_gact *gact;
66 #ifdef CONFIG_GACT_PROB
67 struct tc_gact_p *p_parm = NULL;
73 err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
78 if (tb[TCA_GACT_PARMS] == NULL)
80 parm = nla_data(tb[TCA_GACT_PARMS]);
83 #ifndef CONFIG_GACT_PROB
84 if (tb[TCA_GACT_PROB] != NULL)
87 if (tb[TCA_GACT_PROB]) {
88 p_parm = nla_data(tb[TCA_GACT_PROB]);
89 if (p_parm->ptype >= MAX_RAND)
91 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
92 NL_SET_ERR_MSG(extack,
93 "goto chain not allowed on fallback");
99 err = tcf_idr_check_alloc(tn, &index, a, bind);
101 ret = tcf_idr_create(tn, index, est, a,
102 &act_gact_ops, bind, true);
104 tcf_idr_cleanup(tn, index);
108 } else if (err > 0) {
109 if (bind)/* dont override defaults */
112 tcf_idr_release(*a, bind);
119 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
124 spin_lock_bh(&gact->tcf_lock);
125 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
126 #ifdef CONFIG_GACT_PROB
128 gact->tcfg_paction = p_parm->paction;
129 gact->tcfg_pval = max_t(u16, 1, p_parm->pval);
130 /* Make sure tcfg_pval is written before tcfg_ptype
131 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
134 gact->tcfg_ptype = p_parm->ptype;
137 spin_unlock_bh(&gact->tcf_lock);
140 tcf_chain_put_by_act(goto_ch);
142 if (ret == ACT_P_CREATED)
143 tcf_idr_insert(tn, *a);
146 tcf_idr_release(*a, bind);
150 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a,
151 struct tcf_result *res)
153 struct tcf_gact *gact = to_gact(a);
154 int action = READ_ONCE(gact->tcf_action);
156 #ifdef CONFIG_GACT_PROB
158 u32 ptype = READ_ONCE(gact->tcfg_ptype);
161 action = gact_rand[ptype](gact);
164 tcf_action_update_bstats(&gact->common, skb);
165 if (action == TC_ACT_SHOT)
166 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats));
168 tcf_lastuse_update(&gact->tcf_tm);
173 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets,
174 u64 lastuse, bool hw)
176 struct tcf_gact *gact = to_gact(a);
177 int action = READ_ONCE(gact->tcf_action);
178 struct tcf_t *tm = &gact->tcf_tm;
180 tcf_action_update_stats(a, bytes, packets, action == TC_ACT_SHOT, hw);
181 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
184 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
187 unsigned char *b = skb_tail_pointer(skb);
188 struct tcf_gact *gact = to_gact(a);
189 struct tc_gact opt = {
190 .index = gact->tcf_index,
191 .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
192 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
196 spin_lock_bh(&gact->tcf_lock);
197 opt.action = gact->tcf_action;
198 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
199 goto nla_put_failure;
200 #ifdef CONFIG_GACT_PROB
201 if (gact->tcfg_ptype) {
202 struct tc_gact_p p_opt = {
203 .paction = gact->tcfg_paction,
204 .pval = gact->tcfg_pval,
205 .ptype = gact->tcfg_ptype,
208 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
209 goto nla_put_failure;
212 tcf_tm_dump(&t, &gact->tcf_tm);
213 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
214 goto nla_put_failure;
215 spin_unlock_bh(&gact->tcf_lock);
220 spin_unlock_bh(&gact->tcf_lock);
225 static int tcf_gact_walker(struct net *net, struct sk_buff *skb,
226 struct netlink_callback *cb, int type,
227 const struct tc_action_ops *ops,
228 struct netlink_ext_ack *extack)
230 struct tc_action_net *tn = net_generic(net, gact_net_id);
232 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
235 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index)
237 struct tc_action_net *tn = net_generic(net, gact_net_id);
239 return tcf_idr_search(tn, a, index);
242 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
244 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
246 #ifdef CONFIG_GACT_PROB
247 if (to_gact(act)->tcfg_ptype)
249 sz += nla_total_size(sizeof(struct tc_gact_p));
255 static struct tc_action_ops act_gact_ops = {
258 .owner = THIS_MODULE,
260 .stats_update = tcf_gact_stats_update,
261 .dump = tcf_gact_dump,
262 .init = tcf_gact_init,
263 .walk = tcf_gact_walker,
264 .lookup = tcf_gact_search,
265 .get_fill_size = tcf_gact_get_fill_size,
266 .size = sizeof(struct tcf_gact),
269 static __net_init int gact_init_net(struct net *net)
271 struct tc_action_net *tn = net_generic(net, gact_net_id);
273 return tc_action_net_init(net, tn, &act_gact_ops);
276 static void __net_exit gact_exit_net(struct list_head *net_list)
278 tc_action_net_exit(net_list, gact_net_id);
281 static struct pernet_operations gact_net_ops = {
282 .init = gact_init_net,
283 .exit_batch = gact_exit_net,
285 .size = sizeof(struct tc_action_net),
288 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
289 MODULE_DESCRIPTION("Generic Classifier actions");
290 MODULE_LICENSE("GPL");
292 static int __init gact_init_module(void)
294 #ifdef CONFIG_GACT_PROB
295 pr_info("GACT probability on\n");
297 pr_info("GACT probability NOT on\n");
300 return tcf_register_action(&act_gact_ops, &gact_net_ops);
303 static void __exit gact_cleanup_module(void)
305 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
308 module_init(gact_init_module);
309 module_exit(gact_cleanup_module);