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 <asm/uaccess.h>
14#include <asm/system.h>
15#include <linux/bitops.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/string.h>
19#include <linux/mm.h>
20#include <linux/socket.h>
21#include <linux/sockios.h>
22#include <linux/in.h>
23#include <linux/errno.h>
24#include <linux/interrupt.h>
25#include <linux/netdevice.h>
26#include <linux/skbuff.h>
27#include <linux/rtnetlink.h>
28#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/proc_fs.h>
31#include <net/netlink.h>
32#include <net/sock.h>
33#include <net/pkt_sched.h>
34#include <linux/tc_act/tc_gact.h>
35#include <net/tc_act/tc_gact.h>
36
37#define GACT_TAB_MASK	15
38static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
39static u32 gact_idx_gen;
40static DEFINE_RWLOCK(gact_lock);
41
42static struct tcf_hashinfo gact_hash_info = {
43	.htab	=	tcf_gact_ht,
44	.hmask	=	GACT_TAB_MASK,
45	.lock	=	&gact_lock,
46};
47
48#ifdef CONFIG_GACT_PROB
49static int gact_net_rand(struct tcf_gact *gact)
50{
51	if (!gact->tcfg_pval || net_random() % gact->tcfg_pval)
52		return gact->tcf_action;
53	return gact->tcfg_paction;
54}
55
56static int gact_determ(struct tcf_gact *gact)
57{
58	if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
59		return gact->tcf_action;
60	return gact->tcfg_paction;
61}
62
63typedef int (*g_rand)(struct tcf_gact *gact);
64static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
65#endif /* CONFIG_GACT_PROB */
66
67static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
68			 struct tc_action *a, int ovr, int bind)
69{
70	struct rtattr *tb[TCA_GACT_MAX];
71	struct tc_gact *parm;
72	struct tcf_gact *gact;
73	struct tcf_common *pc;
74	int ret = 0;
75
76	if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
77		return -EINVAL;
78
79	if (tb[TCA_GACT_PARMS - 1] == NULL ||
80	    RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
81		return -EINVAL;
82	parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);
83
84	if (tb[TCA_GACT_PROB-1] != NULL)
85#ifdef CONFIG_GACT_PROB
86		if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
87			return -EINVAL;
88#else
89		return -EOPNOTSUPP;
90#endif
91
92	pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
93	if (!pc) {
94		pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
95				     bind, &gact_idx_gen, &gact_hash_info);
96		if (unlikely(!pc))
97			return -ENOMEM;
98		ret = ACT_P_CREATED;
99	} else {
100		if (!ovr) {
101			tcf_hash_release(pc, bind, &gact_hash_info);
102			return -EEXIST;
103		}
104	}
105
106	gact = to_gact(pc);
107
108	spin_lock_bh(&gact->tcf_lock);
109	gact->tcf_action = parm->action;
110#ifdef CONFIG_GACT_PROB
111	if (tb[TCA_GACT_PROB-1] != NULL) {
112		struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
113		gact->tcfg_paction = p_parm->paction;
114		gact->tcfg_pval    = p_parm->pval;
115		gact->tcfg_ptype   = p_parm->ptype;
116	}
117#endif
118	spin_unlock_bh(&gact->tcf_lock);
119	if (ret == ACT_P_CREATED)
120		tcf_hash_insert(pc, &gact_hash_info);
121	return ret;
122}
123
124static int tcf_gact_cleanup(struct tc_action *a, int bind)
125{
126	struct tcf_gact *gact = a->priv;
127
128	if (gact)
129		return tcf_hash_release(&gact->common, bind, &gact_hash_info);
130	return 0;
131}
132
133static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
134{
135	struct tcf_gact *gact = a->priv;
136	int action = TC_ACT_SHOT;
137
138	spin_lock(&gact->tcf_lock);
139#ifdef CONFIG_GACT_PROB
140	if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
141		action = gact_rand[gact->tcfg_ptype](gact);
142	else
143		action = gact->tcf_action;
144#else
145	action = gact->tcf_action;
146#endif
147	gact->tcf_bstats.bytes += skb->len;
148	gact->tcf_bstats.packets++;
149	if (action == TC_ACT_SHOT)
150		gact->tcf_qstats.drops++;
151	gact->tcf_tm.lastuse = jiffies;
152	spin_unlock(&gact->tcf_lock);
153
154	return action;
155}
156
157static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
158{
159	unsigned char *b = skb_tail_pointer(skb);
160	struct tc_gact opt;
161	struct tcf_gact *gact = a->priv;
162	struct tcf_t t;
163
164	opt.index = gact->tcf_index;
165	opt.refcnt = gact->tcf_refcnt - ref;
166	opt.bindcnt = gact->tcf_bindcnt - bind;
167	opt.action = gact->tcf_action;
168	RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
169#ifdef CONFIG_GACT_PROB
170	if (gact->tcfg_ptype) {
171		struct tc_gact_p p_opt;
172		p_opt.paction = gact->tcfg_paction;
173		p_opt.pval = gact->tcfg_pval;
174		p_opt.ptype = gact->tcfg_ptype;
175		RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
176	}
177#endif
178	t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
179	t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
180	t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
181	RTA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
182	return skb->len;
183
184rtattr_failure:
185	nlmsg_trim(skb, b);
186	return -1;
187}
188
189static struct tc_action_ops act_gact_ops = {
190	.kind		=	"gact",
191	.hinfo		=	&gact_hash_info,
192	.type		=	TCA_ACT_GACT,
193	.capab		=	TCA_CAP_NONE,
194	.owner		=	THIS_MODULE,
195	.act		=	tcf_gact,
196	.dump		=	tcf_gact_dump,
197	.cleanup	=	tcf_gact_cleanup,
198	.lookup		=	tcf_hash_search,
199	.init		=	tcf_gact_init,
200	.walk		=	tcf_generic_walker
201};
202
203MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
204MODULE_DESCRIPTION("Generic Classifier actions");
205MODULE_LICENSE("GPL");
206
207static int __init gact_init_module(void)
208{
209#ifdef CONFIG_GACT_PROB
210	printk("GACT probability on\n");
211#else
212	printk("GACT probability NOT on\n");
213#endif
214	return tcf_register_action(&act_gact_ops);
215}
216
217static void __exit gact_cleanup_module(void)
218{
219	tcf_unregister_action(&act_gact_ops);
220}
221
222module_init(gact_init_module);
223module_exit(gact_cleanup_module);
224