1/*
2 * net/sched/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
27static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
28static u32 gact_idx_gen;
29static DEFINE_RWLOCK(gact_lock);
30
31static struct tcf_hashinfo gact_hash_info = {
32	.htab	=	tcf_gact_ht,
33	.hmask	=	GACT_TAB_MASK,
34	.lock	=	&gact_lock,
35};
36
37#ifdef CONFIG_GACT_PROB
38static int gact_net_rand(struct tcf_gact *gact)
39{
40	if (!gact->tcfg_pval || net_random() % gact->tcfg_pval)
41		return gact->tcf_action;
42	return gact->tcfg_paction;
43}
44
45static int gact_determ(struct tcf_gact *gact)
46{
47	if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
48		return gact->tcf_action;
49	return gact->tcfg_paction;
50}
51
52typedef int (*g_rand)(struct tcf_gact *gact);
53static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
54#endif /* CONFIG_GACT_PROB */
55
56static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
57	[TCA_GACT_PARMS]	= { .len = sizeof(struct tc_gact) },
58	[TCA_GACT_PROB]		= { .len = sizeof(struct tc_gact_p) },
59};
60
61static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
62			 struct tc_action *a, int ovr, int bind)
63{
64	struct nlattr *tb[TCA_GACT_MAX + 1];
65	struct tc_gact *parm;
66	struct tcf_gact *gact;
67	struct tcf_common *pc;
68	int ret = 0;
69	int err;
70
71	if (nla == NULL)
72		return -EINVAL;
73
74	err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
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
82#ifndef CONFIG_GACT_PROB
83	if (tb[TCA_GACT_PROB] != NULL)
84		return -EOPNOTSUPP;
85#endif
86
87	pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
88	if (!pc) {
89		pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
90				     bind, &gact_idx_gen, &gact_hash_info);
91		if (IS_ERR(pc))
92		    return PTR_ERR(pc);
93		ret = ACT_P_CREATED;
94	} else {
95		if (!ovr) {
96			tcf_hash_release(pc, bind, &gact_hash_info);
97			return -EEXIST;
98		}
99	}
100
101	gact = to_gact(pc);
102
103	spin_lock_bh(&gact->tcf_lock);
104	gact->tcf_action = parm->action;
105#ifdef CONFIG_GACT_PROB
106	if (tb[TCA_GACT_PROB] != NULL) {
107		struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]);
108		gact->tcfg_paction = p_parm->paction;
109		gact->tcfg_pval    = p_parm->pval;
110		gact->tcfg_ptype   = p_parm->ptype;
111	}
112#endif
113	spin_unlock_bh(&gact->tcf_lock);
114	if (ret == ACT_P_CREATED)
115		tcf_hash_insert(pc, &gact_hash_info);
116	return ret;
117}
118
119static int tcf_gact_cleanup(struct tc_action *a, int bind)
120{
121	struct tcf_gact *gact = a->priv;
122
123	if (gact)
124		return tcf_hash_release(&gact->common, bind, &gact_hash_info);
125	return 0;
126}
127
128static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
129{
130	struct tcf_gact *gact = a->priv;
131	int action = TC_ACT_SHOT;
132
133	spin_lock(&gact->tcf_lock);
134#ifdef CONFIG_GACT_PROB
135	if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
136		action = gact_rand[gact->tcfg_ptype](gact);
137	else
138		action = gact->tcf_action;
139#else
140	action = gact->tcf_action;
141#endif
142	gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
143	gact->tcf_bstats.packets++;
144	if (action == TC_ACT_SHOT)
145		gact->tcf_qstats.drops++;
146	gact->tcf_tm.lastuse = jiffies;
147	spin_unlock(&gact->tcf_lock);
148
149	return action;
150}
151
152static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
153{
154	unsigned char *b = skb_tail_pointer(skb);
155	struct tcf_gact *gact = a->priv;
156	struct tc_gact opt = {
157		.index   = gact->tcf_index,
158		.refcnt  = gact->tcf_refcnt - ref,
159		.bindcnt = gact->tcf_bindcnt - bind,
160		.action  = gact->tcf_action,
161	};
162	struct tcf_t t;
163
164	NLA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
165#ifdef CONFIG_GACT_PROB
166	if (gact->tcfg_ptype) {
167		struct tc_gact_p p_opt = {
168			.paction = gact->tcfg_paction,
169			.pval    = gact->tcfg_pval,
170			.ptype   = gact->tcfg_ptype,
171		};
172
173		NLA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
174	}
175#endif
176	t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
177	t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
178	t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
179	NLA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
180	return skb->len;
181
182nla_put_failure:
183	nlmsg_trim(skb, b);
184	return -1;
185}
186
187static struct tc_action_ops act_gact_ops = {
188	.kind		=	"gact",
189	.hinfo		=	&gact_hash_info,
190	.type		=	TCA_ACT_GACT,
191	.capab		=	TCA_CAP_NONE,
192	.owner		=	THIS_MODULE,
193	.act		=	tcf_gact,
194	.dump		=	tcf_gact_dump,
195	.cleanup	=	tcf_gact_cleanup,
196	.lookup		=	tcf_hash_search,
197	.init		=	tcf_gact_init,
198	.walk		=	tcf_generic_walker
199};
200
201MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
202MODULE_DESCRIPTION("Generic Classifier actions");
203MODULE_LICENSE("GPL");
204
205static int __init gact_init_module(void)
206{
207#ifdef CONFIG_GACT_PROB
208	printk(KERN_INFO "GACT probability on\n");
209#else
210	printk(KERN_INFO "GACT probability NOT on\n");
211#endif
212	return tcf_register_action(&act_gact_ops);
213}
214
215static void __exit gact_cleanup_module(void)
216{
217	tcf_unregister_action(&act_gact_ops);
218}
219
220module_init(gact_init_module);
221module_exit(gact_cleanup_module);
222