1 /*
2 * net/sched/act_gact.c Generic actions
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * copyright Jamal Hadi Salim (2002-4)
10 *
11 */
12
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/skbuff.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <net/netlink.h>
22 #include <net/pkt_sched.h>
23 #include <linux/tc_act/tc_gact.h>
24 #include <net/tc_act/tc_gact.h>
25
26 #define GACT_TAB_MASK 15
27
28 static unsigned int gact_net_id;
29 static struct tc_action_ops act_gact_ops;
30
31 #ifdef CONFIG_GACT_PROB
32 static int gact_net_rand(struct tcf_gact *gact)
33 {
34 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
35 if (prandom_u32() % gact->tcfg_pval)
36 return gact->tcf_action;
37 return gact->tcfg_paction;
38 }
39
40 static int gact_determ(struct tcf_gact *gact)
41 {
42 u32 pack = atomic_inc_return(&gact->packets);
43
44 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
45 if (pack % gact->tcfg_pval)
46 return gact->tcf_action;
47 return gact->tcfg_paction;
48 }
49
50 typedef int (*g_rand)(struct tcf_gact *gact);
51 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
52 #endif /* CONFIG_GACT_PROB */
53
54 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
55 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) },
56 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) },
57 };
58
59 static int tcf_gact_init(struct net *net, struct nlattr *nla,
60 struct nlattr *est, struct tc_action **a,
61 int ovr, int bind)
62 {
63 struct tc_action_net *tn = net_generic(net, gact_net_id);
64 struct nlattr *tb[TCA_GACT_MAX + 1];
65 struct tc_gact *parm;
66 struct tcf_gact *gact;
67 int ret = 0;
68 int err;
69 #ifdef CONFIG_GACT_PROB
70 struct tc_gact_p *p_parm = NULL;
71 #endif
72
73 if (nla == NULL)
74 return -EINVAL;
75
76 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy, NULL);
77 if (err < 0)
78 return err;
79
80 if (tb[TCA_GACT_PARMS] == NULL)
81 return -EINVAL;
82 parm = nla_data(tb[TCA_GACT_PARMS]);
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 }
93 #endif
94
95 if (!tcf_hash_check(tn, parm->index, a, bind)) {
96 ret = tcf_hash_create(tn, parm->index, est, a,
97 &act_gact_ops, bind, true);
98 if (ret)
99 return ret;
100 ret = ACT_P_CREATED;
101 } else {
102 if (bind)/* dont override defaults */
103 return 0;
104 tcf_hash_release(*a, bind);
105 if (!ovr)
106 return -EEXIST;
107 }
108
109 gact = to_gact(*a);
110
111 ASSERT_RTNL();
112 gact->tcf_action = parm->action;
113 #ifdef CONFIG_GACT_PROB
114 if (p_parm) {
115 gact->tcfg_paction = p_parm->paction;
116 gact->tcfg_pval = max_t(u16, 1, p_parm->pval);
117 /* Make sure tcfg_pval is written before tcfg_ptype
118 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
119 */
120 smp_wmb();
121 gact->tcfg_ptype = p_parm->ptype;
122 }
123 #endif
124 if (ret == ACT_P_CREATED)
125 tcf_hash_insert(tn, *a);
126 return ret;
127 }
128
129 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
130 struct tcf_result *res)
131 {
132 struct tcf_gact *gact = to_gact(a);
133 int action = READ_ONCE(gact->tcf_action);
134
135 #ifdef CONFIG_GACT_PROB
136 {
137 u32 ptype = READ_ONCE(gact->tcfg_ptype);
138
139 if (ptype)
140 action = gact_rand[ptype](gact);
141 }
142 #endif
143 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb);
144 if (action == TC_ACT_SHOT)
145 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats));
146
147 tcf_lastuse_update(&gact->tcf_tm);
148
149 return action;
150 }
151
152 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets,
153 u64 lastuse)
154 {
155 struct tcf_gact *gact = to_gact(a);
156 int action = READ_ONCE(gact->tcf_action);
157 struct tcf_t *tm = &gact->tcf_tm;
158
159 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes,
160 packets);
161 if (action == TC_ACT_SHOT)
162 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets;
163
164 tm->lastuse = lastuse;
165 }
166
167 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
168 int bind, int ref)
169 {
170 unsigned char *b = skb_tail_pointer(skb);
171 struct tcf_gact *gact = to_gact(a);
172 struct tc_gact opt = {
173 .index = gact->tcf_index,
174 .refcnt = gact->tcf_refcnt - ref,
175 .bindcnt = gact->tcf_bindcnt - bind,
176 .action = gact->tcf_action,
177 };
178 struct tcf_t t;
179
180 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
181 goto nla_put_failure;
182 #ifdef CONFIG_GACT_PROB
183 if (gact->tcfg_ptype) {
184 struct tc_gact_p p_opt = {
185 .paction = gact->tcfg_paction,
186 .pval = gact->tcfg_pval,
187 .ptype = gact->tcfg_ptype,
188 };
189
190 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
191 goto nla_put_failure;
192 }
193 #endif
194 tcf_tm_dump(&t, &gact->tcf_tm);
195 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
196 goto nla_put_failure;
197 return skb->len;
198
199 nla_put_failure:
200 nlmsg_trim(skb, b);
201 return -1;
202 }
203
204 static int tcf_gact_walker(struct net *net, struct sk_buff *skb,
205 struct netlink_callback *cb, int type,
206 const struct tc_action_ops *ops)
207 {
208 struct tc_action_net *tn = net_generic(net, gact_net_id);
209
210 return tcf_generic_walker(tn, skb, cb, type, ops);
211 }
212
213 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index)
214 {
215 struct tc_action_net *tn = net_generic(net, gact_net_id);
216
217 return tcf_hash_search(tn, a, index);
218 }
219
220 static struct tc_action_ops act_gact_ops = {
221 .kind = "gact",
222 .type = TCA_ACT_GACT,
223 .owner = THIS_MODULE,
224 .act = tcf_gact,
225 .stats_update = tcf_gact_stats_update,
226 .dump = tcf_gact_dump,
227 .init = tcf_gact_init,
228 .walk = tcf_gact_walker,
229 .lookup = tcf_gact_search,
230 .size = sizeof(struct tcf_gact),
231 };
232
233 static __net_init int gact_init_net(struct net *net)
234 {
235 struct tc_action_net *tn = net_generic(net, gact_net_id);
236
237 return tc_action_net_init(tn, &act_gact_ops, GACT_TAB_MASK);
238 }
239
240 static void __net_exit gact_exit_net(struct net *net)
241 {
242 struct tc_action_net *tn = net_generic(net, gact_net_id);
243
244 tc_action_net_exit(tn);
245 }
246
247 static struct pernet_operations gact_net_ops = {
248 .init = gact_init_net,
249 .exit = gact_exit_net,
250 .id = &gact_net_id,
251 .size = sizeof(struct tc_action_net),
252 };
253
254 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
255 MODULE_DESCRIPTION("Generic Classifier actions");
256 MODULE_LICENSE("GPL");
257
258 static int __init gact_init_module(void)
259 {
260 #ifdef CONFIG_GACT_PROB
261 pr_info("GACT probability on\n");
262 #else
263 pr_info("GACT probability NOT on\n");
264 #endif
265
266 return tcf_register_action(&act_gact_ops, &gact_net_ops);
267 }
268
269 static void __exit gact_cleanup_module(void)
270 {
271 tcf_unregister_action(&act_gact_ops, &gact_net_ops);
272 }
273
274 module_init(gact_init_module);
275 module_exit(gact_cleanup_module);
276
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