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
27
28#ifdef CONFIG_GACT_PROB
29static int gact_net_rand(struct tcf_gact *gact)
30{
31	if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval)
32		return gact->tcf_action;
33	return gact->tcfg_paction;
34}
35
36static int gact_determ(struct tcf_gact *gact)
37{
38	if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
39		return gact->tcf_action;
40	return gact->tcfg_paction;
41}
42
43typedef int (*g_rand)(struct tcf_gact *gact);
44static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
45#endif /* CONFIG_GACT_PROB */
46
47static 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
52static int tcf_gact_init(struct net *net, struct nlattr *nla,
53			 struct nlattr *est, struct tc_action *a,
54			 int ovr, int bind)
55{
56	struct nlattr *tb[TCA_GACT_MAX + 1];
57	struct tc_gact *parm;
58	struct tcf_gact *gact;
59	int ret = 0;
60	int err;
61#ifdef CONFIG_GACT_PROB
62	struct tc_gact_p *p_parm = NULL;
63#endif
64
65	if (nla == NULL)
66		return -EINVAL;
67
68	err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
69	if (err < 0)
70		return err;
71
72	if (tb[TCA_GACT_PARMS] == NULL)
73		return -EINVAL;
74	parm = nla_data(tb[TCA_GACT_PARMS]);
75
76#ifndef CONFIG_GACT_PROB
77	if (tb[TCA_GACT_PROB] != NULL)
78		return -EOPNOTSUPP;
79#else
80	if (tb[TCA_GACT_PROB]) {
81		p_parm = nla_data(tb[TCA_GACT_PROB]);
82		if (p_parm->ptype >= MAX_RAND)
83			return -EINVAL;
84	}
85#endif
86
87	if (!tcf_hash_check(parm->index, a, bind)) {
88		ret = tcf_hash_create(parm->index, est, a, sizeof(*gact), bind);
89		if (ret)
90			return ret;
91		ret = ACT_P_CREATED;
92	} else {
93		if (bind)/* dont override defaults */
94			return 0;
95		tcf_hash_release(a, bind);
96		if (!ovr)
97			return -EEXIST;
98	}
99
100	gact = to_gact(a);
101
102	spin_lock_bh(&gact->tcf_lock);
103	gact->tcf_action = parm->action;
104#ifdef CONFIG_GACT_PROB
105	if (p_parm) {
106		gact->tcfg_paction = p_parm->paction;
107		gact->tcfg_pval    = p_parm->pval;
108		gact->tcfg_ptype   = p_parm->ptype;
109	}
110#endif
111	spin_unlock_bh(&gact->tcf_lock);
112	if (ret == ACT_P_CREATED)
113		tcf_hash_insert(a);
114	return ret;
115}
116
117static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
118		    struct tcf_result *res)
119{
120	struct tcf_gact *gact = a->priv;
121	int action = TC_ACT_SHOT;
122
123	spin_lock(&gact->tcf_lock);
124#ifdef CONFIG_GACT_PROB
125	if (gact->tcfg_ptype)
126		action = gact_rand[gact->tcfg_ptype](gact);
127	else
128		action = gact->tcf_action;
129#else
130	action = gact->tcf_action;
131#endif
132	gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
133	gact->tcf_bstats.packets++;
134	if (action == TC_ACT_SHOT)
135		gact->tcf_qstats.drops++;
136	gact->tcf_tm.lastuse = jiffies;
137	spin_unlock(&gact->tcf_lock);
138
139	return action;
140}
141
142static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
143{
144	unsigned char *b = skb_tail_pointer(skb);
145	struct tcf_gact *gact = a->priv;
146	struct tc_gact opt = {
147		.index   = gact->tcf_index,
148		.refcnt  = gact->tcf_refcnt - ref,
149		.bindcnt = gact->tcf_bindcnt - bind,
150		.action  = gact->tcf_action,
151	};
152	struct tcf_t t;
153
154	if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
155		goto nla_put_failure;
156#ifdef CONFIG_GACT_PROB
157	if (gact->tcfg_ptype) {
158		struct tc_gact_p p_opt = {
159			.paction = gact->tcfg_paction,
160			.pval    = gact->tcfg_pval,
161			.ptype   = gact->tcfg_ptype,
162		};
163
164		if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
165			goto nla_put_failure;
166	}
167#endif
168	t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
169	t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
170	t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
171	if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
172		goto nla_put_failure;
173	return skb->len;
174
175nla_put_failure:
176	nlmsg_trim(skb, b);
177	return -1;
178}
179
180static struct tc_action_ops act_gact_ops = {
181	.kind		=	"gact",
182	.type		=	TCA_ACT_GACT,
183	.owner		=	THIS_MODULE,
184	.act		=	tcf_gact,
185	.dump		=	tcf_gact_dump,
186	.init		=	tcf_gact_init,
187};
188
189MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
190MODULE_DESCRIPTION("Generic Classifier actions");
191MODULE_LICENSE("GPL");
192
193static int __init gact_init_module(void)
194{
195#ifdef CONFIG_GACT_PROB
196	pr_info("GACT probability on\n");
197#else
198	pr_info("GACT probability NOT on\n");
199#endif
200	return tcf_register_action(&act_gact_ops, GACT_TAB_MASK);
201}
202
203static void __exit gact_cleanup_module(void)
204{
205	tcf_unregister_action(&act_gact_ops);
206}
207
208module_init(gact_init_module);
209module_exit(gact_cleanup_module);
210