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
22 static unsigned int gact_net_id;
23 static struct tc_action_ops act_gact_ops;
24
25 #ifdef CONFIG_GACT_PROB
gact_net_rand(struct tcf_gact * gact)26 static int gact_net_rand(struct tcf_gact *gact)
27 {
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;
32 }
33
gact_determ(struct tcf_gact * gact)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
tcf_gact_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,struct netlink_ext_ack * extack)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)
57 {
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;
61 struct tc_gact *parm;
62 struct tcf_gact *gact;
63 int ret = 0;
64 u32 index;
65 int err;
66 #ifdef CONFIG_GACT_PROB
67 struct tc_gact_p *p_parm = NULL;
68 #endif
69
70 if (nla == NULL)
71 return -EINVAL;
72
73 err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
74 NULL);
75 if (err < 0)
76 return err;
77
78 if (tb[TCA_GACT_PARMS] == NULL)
79 return -EINVAL;
80 parm = nla_data(tb[TCA_GACT_PARMS]);
81 index = parm->index;
82
83 #ifndef CONFIG_GACT_PROB
84 if (tb[TCA_GACT_PROB] != NULL)
85 return -EOPNOTSUPP;
86 #else
87 if (tb[TCA_GACT_PROB]) {
88 p_parm = nla_data(tb[TCA_GACT_PROB]);
89 if (p_parm->ptype >= MAX_RAND)
90 return -EINVAL;
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");
94 return -EINVAL;
95 }
96 }
97 #endif
98
99 err = tcf_idr_check_alloc(tn, &index, a, bind);
100 if (!err) {
101 ret = tcf_idr_create(tn, index, est, a,
102 &act_gact_ops, bind, true);
103 if (ret) {
104 tcf_idr_cleanup(tn, index);
105 return ret;
106 }
107 ret = ACT_P_CREATED;
108 } else if (err > 0) {
109 if (bind)/* dont override defaults */
110 return 0;
111 if (!ovr) {
112 tcf_idr_release(*a, bind);
113 return -EEXIST;
114 }
115 } else {
116 return err;
117 }
118
119 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
120 if (err < 0)
121 goto release_idr;
122 gact = to_gact(*a);
123
124 spin_lock_bh(&gact->tcf_lock);
125 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
126 #ifdef CONFIG_GACT_PROB
127 if (p_parm) {
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()
132 */
133 smp_wmb();
134 gact->tcfg_ptype = p_parm->ptype;
135 }
136 #endif
137 spin_unlock_bh(&gact->tcf_lock);
138
139 if (goto_ch)
140 tcf_chain_put_by_act(goto_ch);
141
142 if (ret == ACT_P_CREATED)
143 tcf_idr_insert(tn, *a);
144 return ret;
145 release_idr:
146 tcf_idr_release(*a, bind);
147 return err;
148 }
149
tcf_gact_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)150 static int tcf_gact_act(struct sk_buff *skb, 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 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb);
165 if (action == TC_ACT_SHOT)
166 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats));
167
168 tcf_lastuse_update(&gact->tcf_tm);
169
170 return action;
171 }
172
tcf_gact_stats_update(struct tc_action * a,u64 bytes,u32 packets,u64 lastuse,bool hw)173 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets,
174 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 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes,
181 packets);
182 if (action == TC_ACT_SHOT)
183 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets;
184
185 if (hw)
186 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats_hw),
187 bytes, packets);
188
189 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
190 }
191
tcf_gact_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)192 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
193 int bind, int ref)
194 {
195 unsigned char *b = skb_tail_pointer(skb);
196 struct tcf_gact *gact = to_gact(a);
197 struct tc_gact opt = {
198 .index = gact->tcf_index,
199 .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
200 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
201 };
202 struct tcf_t t;
203
204 spin_lock_bh(&gact->tcf_lock);
205 opt.action = gact->tcf_action;
206 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
207 goto nla_put_failure;
208 #ifdef CONFIG_GACT_PROB
209 if (gact->tcfg_ptype) {
210 struct tc_gact_p p_opt = {
211 .paction = gact->tcfg_paction,
212 .pval = gact->tcfg_pval,
213 .ptype = gact->tcfg_ptype,
214 };
215
216 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
217 goto nla_put_failure;
218 }
219 #endif
220 tcf_tm_dump(&t, &gact->tcf_tm);
221 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
222 goto nla_put_failure;
223 spin_unlock_bh(&gact->tcf_lock);
224
225 return skb->len;
226
227 nla_put_failure:
228 spin_unlock_bh(&gact->tcf_lock);
229 nlmsg_trim(skb, b);
230 return -1;
231 }
232
tcf_gact_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)233 static int tcf_gact_walker(struct net *net, struct sk_buff *skb,
234 struct netlink_callback *cb, int type,
235 const struct tc_action_ops *ops,
236 struct netlink_ext_ack *extack)
237 {
238 struct tc_action_net *tn = net_generic(net, gact_net_id);
239
240 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
241 }
242
tcf_gact_search(struct net * net,struct tc_action ** a,u32 index)243 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index)
244 {
245 struct tc_action_net *tn = net_generic(net, gact_net_id);
246
247 return tcf_idr_search(tn, a, index);
248 }
249
tcf_gact_get_fill_size(const struct tc_action * act)250 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
251 {
252 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
253
254 #ifdef CONFIG_GACT_PROB
255 if (to_gact(act)->tcfg_ptype)
256 /* TCA_GACT_PROB */
257 sz += nla_total_size(sizeof(struct tc_gact_p));
258 #endif
259
260 return sz;
261 }
262
263 static struct tc_action_ops act_gact_ops = {
264 .kind = "gact",
265 .id = TCA_ID_GACT,
266 .owner = THIS_MODULE,
267 .act = tcf_gact_act,
268 .stats_update = tcf_gact_stats_update,
269 .dump = tcf_gact_dump,
270 .init = tcf_gact_init,
271 .walk = tcf_gact_walker,
272 .lookup = tcf_gact_search,
273 .get_fill_size = tcf_gact_get_fill_size,
274 .size = sizeof(struct tcf_gact),
275 };
276
gact_init_net(struct net * net)277 static __net_init int gact_init_net(struct net *net)
278 {
279 struct tc_action_net *tn = net_generic(net, gact_net_id);
280
281 return tc_action_net_init(net, tn, &act_gact_ops);
282 }
283
gact_exit_net(struct list_head * net_list)284 static void __net_exit gact_exit_net(struct list_head *net_list)
285 {
286 tc_action_net_exit(net_list, gact_net_id);
287 }
288
289 static struct pernet_operations gact_net_ops = {
290 .init = gact_init_net,
291 .exit_batch = gact_exit_net,
292 .id = &gact_net_id,
293 .size = sizeof(struct tc_action_net),
294 };
295
296 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
297 MODULE_DESCRIPTION("Generic Classifier actions");
298 MODULE_LICENSE("GPL");
299
gact_init_module(void)300 static int __init gact_init_module(void)
301 {
302 #ifdef CONFIG_GACT_PROB
303 pr_info("GACT probability on\n");
304 #else
305 pr_info("GACT probability NOT on\n");
306 #endif
307
308 return tcf_register_action(&act_gact_ops, &gact_net_ops);
309 }
310
gact_cleanup_module(void)311 static void __exit gact_cleanup_module(void)
312 {
313 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
314 }
315
316 module_init(gact_init_module);
317 module_exit(gact_cleanup_module);
318