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 struct tc_action_ops act_gact_ops;
23
24 #ifdef CONFIG_GACT_PROB
gact_net_rand(struct tcf_gact * gact)25 static int gact_net_rand(struct tcf_gact *gact)
26 {
27 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
28 if (prandom_u32_max(gact->tcfg_pval))
29 return gact->tcf_action;
30 return gact->tcfg_paction;
31 }
32
gact_determ(struct tcf_gact * gact)33 static int gact_determ(struct tcf_gact *gact)
34 {
35 u32 pack = atomic_inc_return(&gact->packets);
36
37 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
38 if (pack % gact->tcfg_pval)
39 return gact->tcf_action;
40 return gact->tcfg_paction;
41 }
42
43 typedef int (*g_rand)(struct tcf_gact *gact);
44 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
45 #endif /* CONFIG_GACT_PROB */
46
47 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
48 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) },
49 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) },
50 };
51
tcf_gact_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)52 static int tcf_gact_init(struct net *net, struct nlattr *nla,
53 struct nlattr *est, struct tc_action **a,
54 struct tcf_proto *tp, u32 flags,
55 struct netlink_ext_ack *extack)
56 {
57 struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
58 bool bind = flags & TCA_ACT_FLAGS_BIND;
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_from_flags(tn, index, est, a,
102 &act_gact_ops, bind, flags);
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 (!(flags & TCA_ACT_FLAGS_REPLACE)) {
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 return ret;
143 release_idr:
144 tcf_idr_release(*a, bind);
145 return err;
146 }
147
tcf_gact_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)148 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a,
149 struct tcf_result *res)
150 {
151 struct tcf_gact *gact = to_gact(a);
152 int action = READ_ONCE(gact->tcf_action);
153
154 #ifdef CONFIG_GACT_PROB
155 {
156 u32 ptype = READ_ONCE(gact->tcfg_ptype);
157
158 if (ptype)
159 action = gact_rand[ptype](gact);
160 }
161 #endif
162 tcf_action_update_bstats(&gact->common, skb);
163 if (action == TC_ACT_SHOT)
164 tcf_action_inc_drop_qstats(&gact->common);
165
166 tcf_lastuse_update(&gact->tcf_tm);
167
168 return action;
169 }
170
tcf_gact_stats_update(struct tc_action * a,u64 bytes,u64 packets,u64 drops,u64 lastuse,bool hw)171 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
172 u64 drops, u64 lastuse, bool hw)
173 {
174 struct tcf_gact *gact = to_gact(a);
175 int action = READ_ONCE(gact->tcf_action);
176 struct tcf_t *tm = &gact->tcf_tm;
177
178 tcf_action_update_stats(a, bytes, packets,
179 action == TC_ACT_SHOT ? packets : drops, hw);
180 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
181 }
182
tcf_gact_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)183 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
184 int bind, int ref)
185 {
186 unsigned char *b = skb_tail_pointer(skb);
187 struct tcf_gact *gact = to_gact(a);
188 struct tc_gact opt = {
189 .index = gact->tcf_index,
190 .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
191 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
192 };
193 struct tcf_t t;
194
195 spin_lock_bh(&gact->tcf_lock);
196 opt.action = gact->tcf_action;
197 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
198 goto nla_put_failure;
199 #ifdef CONFIG_GACT_PROB
200 if (gact->tcfg_ptype) {
201 struct tc_gact_p p_opt = {
202 .paction = gact->tcfg_paction,
203 .pval = gact->tcfg_pval,
204 .ptype = gact->tcfg_ptype,
205 };
206
207 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
208 goto nla_put_failure;
209 }
210 #endif
211 tcf_tm_dump(&t, &gact->tcf_tm);
212 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
213 goto nla_put_failure;
214 spin_unlock_bh(&gact->tcf_lock);
215
216 return skb->len;
217
218 nla_put_failure:
219 spin_unlock_bh(&gact->tcf_lock);
220 nlmsg_trim(skb, b);
221 return -1;
222 }
223
tcf_gact_get_fill_size(const struct tc_action * act)224 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
225 {
226 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
227
228 #ifdef CONFIG_GACT_PROB
229 if (to_gact(act)->tcfg_ptype)
230 /* TCA_GACT_PROB */
231 sz += nla_total_size(sizeof(struct tc_gact_p));
232 #endif
233
234 return sz;
235 }
236
tcf_gact_offload_act_setup(struct tc_action * act,void * entry_data,u32 * index_inc,bool bind,struct netlink_ext_ack * extack)237 static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
238 u32 *index_inc, bool bind,
239 struct netlink_ext_ack *extack)
240 {
241 if (bind) {
242 struct flow_action_entry *entry = entry_data;
243
244 if (is_tcf_gact_ok(act)) {
245 entry->id = FLOW_ACTION_ACCEPT;
246 } else if (is_tcf_gact_shot(act)) {
247 entry->id = FLOW_ACTION_DROP;
248 } else if (is_tcf_gact_trap(act)) {
249 entry->id = FLOW_ACTION_TRAP;
250 } else if (is_tcf_gact_goto_chain(act)) {
251 entry->id = FLOW_ACTION_GOTO;
252 entry->chain_index = tcf_gact_goto_chain_index(act);
253 } else if (is_tcf_gact_continue(act)) {
254 NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
255 return -EOPNOTSUPP;
256 } else if (is_tcf_gact_reclassify(act)) {
257 NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
258 return -EOPNOTSUPP;
259 } else if (is_tcf_gact_pipe(act)) {
260 NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
261 return -EOPNOTSUPP;
262 } else {
263 NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
264 return -EOPNOTSUPP;
265 }
266 *index_inc = 1;
267 } else {
268 struct flow_offload_action *fl_action = entry_data;
269
270 if (is_tcf_gact_ok(act))
271 fl_action->id = FLOW_ACTION_ACCEPT;
272 else if (is_tcf_gact_shot(act))
273 fl_action->id = FLOW_ACTION_DROP;
274 else if (is_tcf_gact_trap(act))
275 fl_action->id = FLOW_ACTION_TRAP;
276 else if (is_tcf_gact_goto_chain(act))
277 fl_action->id = FLOW_ACTION_GOTO;
278 else
279 return -EOPNOTSUPP;
280 }
281
282 return 0;
283 }
284
285 static struct tc_action_ops act_gact_ops = {
286 .kind = "gact",
287 .id = TCA_ID_GACT,
288 .owner = THIS_MODULE,
289 .act = tcf_gact_act,
290 .stats_update = tcf_gact_stats_update,
291 .dump = tcf_gact_dump,
292 .init = tcf_gact_init,
293 .get_fill_size = tcf_gact_get_fill_size,
294 .offload_act_setup = tcf_gact_offload_act_setup,
295 .size = sizeof(struct tcf_gact),
296 };
297
gact_init_net(struct net * net)298 static __net_init int gact_init_net(struct net *net)
299 {
300 struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
301
302 return tc_action_net_init(net, tn, &act_gact_ops);
303 }
304
gact_exit_net(struct list_head * net_list)305 static void __net_exit gact_exit_net(struct list_head *net_list)
306 {
307 tc_action_net_exit(net_list, act_gact_ops.net_id);
308 }
309
310 static struct pernet_operations gact_net_ops = {
311 .init = gact_init_net,
312 .exit_batch = gact_exit_net,
313 .id = &act_gact_ops.net_id,
314 .size = sizeof(struct tc_action_net),
315 };
316
317 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
318 MODULE_DESCRIPTION("Generic Classifier actions");
319 MODULE_LICENSE("GPL");
320
gact_init_module(void)321 static int __init gact_init_module(void)
322 {
323 #ifdef CONFIG_GACT_PROB
324 pr_info("GACT probability on\n");
325 #else
326 pr_info("GACT probability NOT on\n");
327 #endif
328
329 return tcf_register_action(&act_gact_ops, &gact_net_ops);
330 }
331
gact_cleanup_module(void)332 static void __exit gact_cleanup_module(void)
333 {
334 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
335 }
336
337 module_init(gact_init_module);
338 module_exit(gact_cleanup_module);
339
