xref: /linux/net/sched/act_gact.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/sched.h>
19 #include <linux/string.h>
20 #include <linux/mm.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/interrupt.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/rtnetlink.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/proc_fs.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 /* use generic hash table */
38 #define MY_TAB_SIZE	16
39 #define MY_TAB_MASK	15
40 
41 static u32 idx_gen;
42 static struct tcf_gact *tcf_gact_ht[MY_TAB_SIZE];
43 static DEFINE_RWLOCK(gact_lock);
44 
45 /* ovewrride the defaults */
46 #define tcf_st		tcf_gact
47 #define tc_st		tc_gact
48 #define tcf_t_lock	gact_lock
49 #define tcf_ht		tcf_gact_ht
50 
51 #define CONFIG_NET_ACT_INIT 1
52 #include <net/pkt_act.h>
53 
54 #ifdef CONFIG_GACT_PROB
55 static int gact_net_rand(struct tcf_gact *p)
56 {
57 	if (net_random()%p->pval)
58 		return p->action;
59 	return p->paction;
60 }
61 
62 static int gact_determ(struct tcf_gact *p)
63 {
64 	if (p->bstats.packets%p->pval)
65 		return p->action;
66 	return p->paction;
67 }
68 
69 typedef int (*g_rand)(struct tcf_gact *p);
70 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
71 #endif
72 
73 static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
74                          struct tc_action *a, int ovr, int bind)
75 {
76 	struct rtattr *tb[TCA_GACT_MAX];
77 	struct tc_gact *parm;
78 	struct tcf_gact *p;
79 	int ret = 0;
80 
81 	if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
82 		return -EINVAL;
83 
84 	if (tb[TCA_GACT_PARMS - 1] == NULL ||
85 	    RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
86 		return -EINVAL;
87 	parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);
88 
89 	if (tb[TCA_GACT_PROB-1] != NULL)
90 #ifdef CONFIG_GACT_PROB
91 		if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
92 			return -EINVAL;
93 #else
94 		return -EOPNOTSUPP;
95 #endif
96 
97 	p = tcf_hash_check(parm->index, a, ovr, bind);
98 	if (p == NULL) {
99 		p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
100 		if (p == NULL)
101 			return -ENOMEM;
102 		ret = ACT_P_CREATED;
103 	} else {
104 		if (!ovr) {
105 			tcf_hash_release(p, bind);
106 			return -EEXIST;
107 		}
108 	}
109 
110 	spin_lock_bh(&p->lock);
111 	p->action = parm->action;
112 #ifdef CONFIG_GACT_PROB
113 	if (tb[TCA_GACT_PROB-1] != NULL) {
114 		struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
115 		p->paction = p_parm->paction;
116 		p->pval    = p_parm->pval;
117 		p->ptype   = p_parm->ptype;
118 	}
119 #endif
120 	spin_unlock_bh(&p->lock);
121 	if (ret == ACT_P_CREATED)
122 		tcf_hash_insert(p);
123 	return ret;
124 }
125 
126 static int
127 tcf_gact_cleanup(struct tc_action *a, int bind)
128 {
129 	struct tcf_gact *p = PRIV(a, gact);
130 
131 	if (p != NULL)
132 		return tcf_hash_release(p, bind);
133 	return 0;
134 }
135 
136 static int
137 tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
138 {
139 	struct tcf_gact *p = PRIV(a, gact);
140 	int action = TC_ACT_SHOT;
141 
142 	spin_lock(&p->lock);
143 #ifdef CONFIG_GACT_PROB
144 	if (p->ptype && gact_rand[p->ptype] != NULL)
145 		action = gact_rand[p->ptype](p);
146 	else
147 		action = p->action;
148 #else
149 	action = p->action;
150 #endif
151 	p->bstats.bytes += skb->len;
152 	p->bstats.packets++;
153 	if (action == TC_ACT_SHOT)
154 		p->qstats.drops++;
155 	p->tm.lastuse = jiffies;
156 	spin_unlock(&p->lock);
157 
158 	return action;
159 }
160 
161 static int
162 tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
163 {
164 	unsigned char *b = skb->tail;
165 	struct tc_gact opt;
166 	struct tcf_gact *p = PRIV(a, gact);
167 	struct tcf_t t;
168 
169 	opt.index = p->index;
170 	opt.refcnt = p->refcnt - ref;
171 	opt.bindcnt = p->bindcnt - bind;
172 	opt.action = p->action;
173 	RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
174 #ifdef CONFIG_GACT_PROB
175 	if (p->ptype) {
176 		struct tc_gact_p p_opt;
177 		p_opt.paction = p->paction;
178 		p_opt.pval = p->pval;
179 		p_opt.ptype = p->ptype;
180 		RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
181 	}
182 #endif
183 	t.install = jiffies_to_clock_t(jiffies - p->tm.install);
184 	t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
185 	t.expires = jiffies_to_clock_t(p->tm.expires);
186 	RTA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
187 	return skb->len;
188 
189       rtattr_failure:
190 	skb_trim(skb, b - skb->data);
191 	return -1;
192 }
193 
194 static struct tc_action_ops act_gact_ops = {
195 	.kind		=	"gact",
196 	.type		=	TCA_ACT_GACT,
197 	.capab		=	TCA_CAP_NONE,
198 	.owner		=	THIS_MODULE,
199 	.act		=	tcf_gact,
200 	.dump		=	tcf_gact_dump,
201 	.cleanup	=	tcf_gact_cleanup,
202 	.lookup		=	tcf_hash_search,
203 	.init		=	tcf_gact_init,
204 	.walk		=	tcf_generic_walker
205 };
206 
207 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
208 MODULE_DESCRIPTION("Generic Classifier actions");
209 MODULE_LICENSE("GPL");
210 
211 static int __init
212 gact_init_module(void)
213 {
214 #ifdef CONFIG_GACT_PROB
215 	printk("GACT probability on\n");
216 #else
217 	printk("GACT probability NOT on\n");
218 #endif
219 	return tcf_register_action(&act_gact_ops);
220 }
221 
222 static void __exit
223 gact_cleanup_module(void)
224 {
225 	tcf_unregister_action(&act_gact_ops);
226 }
227 
228 module_init(gact_init_module);
229 module_exit(gact_cleanup_module);
230