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
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 (get_random_u32_below(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,struct tcf_proto * tp,u32 flags,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 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 (!tcf_action_valid(p_parm->paction)) {
93 NL_SET_ERR_MSG(extack,
94 "invalid fallback control action");
95 return -EINVAL;
96 }
97 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
98 NL_SET_ERR_MSG(extack,
99 "goto chain not allowed on fallback");
100 return -EINVAL;
101 }
102 }
103 #endif
104
105 err = tcf_idr_check_alloc(tn, &index, a, bind);
106 if (!err) {
107 ret = tcf_idr_create_from_flags(tn, index, est, a,
108 &act_gact_ops, bind, flags);
109 if (ret) {
110 tcf_idr_cleanup(tn, index);
111 return ret;
112 }
113 ret = ACT_P_CREATED;
114 } else if (err > 0) {
115 if (bind)/* dont override defaults */
116 return ACT_P_BOUND;
117 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
118 tcf_idr_release(*a, bind);
119 return -EEXIST;
120 }
121 } else {
122 return err;
123 }
124
125 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
126 if (err < 0)
127 goto release_idr;
128 gact = to_gact(*a);
129
130 spin_lock_bh(&gact->tcf_lock);
131 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
132 #ifdef CONFIG_GACT_PROB
133 if (p_parm) {
134 gact->tcfg_paction = p_parm->paction;
135 gact->tcfg_pval = max_t(u16, 1, p_parm->pval);
136 /* Make sure tcfg_pval is written before tcfg_ptype
137 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
138 */
139 smp_wmb();
140 gact->tcfg_ptype = p_parm->ptype;
141 }
142 #endif
143 spin_unlock_bh(&gact->tcf_lock);
144
145 if (goto_ch)
146 tcf_chain_put_by_act(goto_ch);
147
148 return ret;
149 release_idr:
150 tcf_idr_release(*a, bind);
151 return err;
152 }
153
tcf_gact_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)154 TC_INDIRECT_SCOPE int tcf_gact_act(struct sk_buff *skb,
155 const struct tc_action *a,
156 struct tcf_result *res)
157 {
158 struct tcf_gact *gact = to_gact(a);
159 int action = READ_ONCE(gact->tcf_action);
160
161 #ifdef CONFIG_GACT_PROB
162 {
163 u32 ptype = READ_ONCE(gact->tcfg_ptype);
164
165 if (ptype)
166 action = gact_rand[ptype](gact);
167 }
168 #endif
169 tcf_action_update_bstats(&gact->common, skb);
170 if (action == TC_ACT_SHOT)
171 tcf_action_inc_drop_qstats(&gact->common);
172
173 tcf_lastuse_update(&gact->tcf_tm);
174
175 return action;
176 }
177
tcf_gact_stats_update(struct tc_action * a,u64 bytes,u64 packets,u64 drops,u64 lastuse,bool hw)178 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
179 u64 drops, u64 lastuse, bool hw)
180 {
181 struct tcf_gact *gact = to_gact(a);
182 int action = READ_ONCE(gact->tcf_action);
183 struct tcf_t *tm = &gact->tcf_tm;
184
185 tcf_action_update_stats(a, bytes, packets,
186 action == TC_ACT_SHOT ? packets : drops, hw);
187 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
188 }
189
tcf_gact_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)190 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
191 int bind, int ref)
192 {
193 unsigned char *b = skb_tail_pointer(skb);
194 struct tcf_gact *gact = to_gact(a);
195 struct tc_gact opt = {
196 .index = gact->tcf_index,
197 .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
198 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
199 };
200 struct tcf_t t;
201
202 spin_lock_bh(&gact->tcf_lock);
203 opt.action = gact->tcf_action;
204 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
205 goto nla_put_failure;
206 #ifdef CONFIG_GACT_PROB
207 if (gact->tcfg_ptype) {
208 struct tc_gact_p p_opt = {
209 .paction = gact->tcfg_paction,
210 .pval = gact->tcfg_pval,
211 .ptype = gact->tcfg_ptype,
212 };
213
214 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
215 goto nla_put_failure;
216 }
217 #endif
218 tcf_tm_dump(&t, &gact->tcf_tm);
219 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
220 goto nla_put_failure;
221 spin_unlock_bh(&gact->tcf_lock);
222
223 return skb->len;
224
225 nla_put_failure:
226 spin_unlock_bh(&gact->tcf_lock);
227 nlmsg_trim(skb, b);
228 return -1;
229 }
230
tcf_gact_get_fill_size(const struct tc_action * act)231 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
232 {
233 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
234
235 #ifdef CONFIG_GACT_PROB
236 if (to_gact(act)->tcfg_ptype)
237 /* TCA_GACT_PROB */
238 sz += nla_total_size(sizeof(struct tc_gact_p));
239 #endif
240
241 return sz;
242 }
243
tcf_gact_offload_act_setup(struct tc_action * act,void * entry_data,u32 * index_inc,bool bind,struct netlink_ext_ack * extack)244 static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
245 u32 *index_inc, bool bind,
246 struct netlink_ext_ack *extack)
247 {
248 if (bind) {
249 struct flow_action_entry *entry = entry_data;
250
251 if (is_tcf_gact_ok(act)) {
252 entry->id = FLOW_ACTION_ACCEPT;
253 } else if (is_tcf_gact_shot(act)) {
254 entry->id = FLOW_ACTION_DROP;
255 } else if (is_tcf_gact_trap(act)) {
256 entry->id = FLOW_ACTION_TRAP;
257 } else if (is_tcf_gact_goto_chain(act)) {
258 entry->id = FLOW_ACTION_GOTO;
259 entry->chain_index = tcf_gact_goto_chain_index(act);
260 } else if (is_tcf_gact_continue(act)) {
261 NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
262 return -EOPNOTSUPP;
263 } else if (is_tcf_gact_reclassify(act)) {
264 NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
265 return -EOPNOTSUPP;
266 } else if (is_tcf_gact_pipe(act)) {
267 NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
268 return -EOPNOTSUPP;
269 } else {
270 NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
271 return -EOPNOTSUPP;
272 }
273 *index_inc = 1;
274 } else {
275 struct flow_offload_action *fl_action = entry_data;
276
277 if (is_tcf_gact_ok(act))
278 fl_action->id = FLOW_ACTION_ACCEPT;
279 else if (is_tcf_gact_shot(act))
280 fl_action->id = FLOW_ACTION_DROP;
281 else if (is_tcf_gact_trap(act))
282 fl_action->id = FLOW_ACTION_TRAP;
283 else if (is_tcf_gact_goto_chain(act))
284 fl_action->id = FLOW_ACTION_GOTO;
285 else
286 return -EOPNOTSUPP;
287 }
288
289 return 0;
290 }
291
292 static struct tc_action_ops act_gact_ops = {
293 .kind = "gact",
294 .id = TCA_ID_GACT,
295 .owner = THIS_MODULE,
296 .act = tcf_gact_act,
297 .stats_update = tcf_gact_stats_update,
298 .dump = tcf_gact_dump,
299 .init = tcf_gact_init,
300 .get_fill_size = tcf_gact_get_fill_size,
301 .offload_act_setup = tcf_gact_offload_act_setup,
302 .size = sizeof(struct tcf_gact),
303 };
304 MODULE_ALIAS_NET_ACT("gact");
305
gact_init_net(struct net * net)306 static __net_init int gact_init_net(struct net *net)
307 {
308 struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
309
310 return tc_action_net_init(net, tn, &act_gact_ops);
311 }
312
gact_exit_net(struct list_head * net_list)313 static void __net_exit gact_exit_net(struct list_head *net_list)
314 {
315 tc_action_net_exit(net_list, act_gact_ops.net_id);
316 }
317
318 static struct pernet_operations gact_net_ops = {
319 .init = gact_init_net,
320 .exit_batch = gact_exit_net,
321 .id = &act_gact_ops.net_id,
322 .size = sizeof(struct tc_action_net),
323 };
324
325 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
326 MODULE_DESCRIPTION("Generic Classifier actions");
327 MODULE_LICENSE("GPL");
328
gact_init_module(void)329 static int __init gact_init_module(void)
330 {
331 #ifdef CONFIG_GACT_PROB
332 pr_info("GACT probability on\n");
333 #else
334 pr_info("GACT probability NOT on\n");
335 #endif
336
337 return tcf_register_action(&act_gact_ops, &gact_net_ops);
338 }
339
gact_cleanup_module(void)340 static void __exit gact_cleanup_module(void)
341 {
342 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
343 }
344
345 module_init(gact_init_module);
346 module_exit(gact_cleanup_module);
347