xref: /openbmc/linux/net/sched/act_gact.c (revision 87c2ce3b)
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/config.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/string.h>
21 #include <linux/mm.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/in.h>
25 #include <linux/errno.h>
26 #include <linux/interrupt.h>
27 #include <linux/netdevice.h>
28 #include <linux/skbuff.h>
29 #include <linux/rtnetlink.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/proc_fs.h>
33 #include <net/sock.h>
34 #include <net/pkt_sched.h>
35 #include <linux/tc_act/tc_gact.h>
36 #include <net/tc_act/tc_gact.h>
37 
38 /* use generic hash table */
39 #define MY_TAB_SIZE	16
40 #define MY_TAB_MASK	15
41 
42 static u32 idx_gen;
43 static struct tcf_gact *tcf_gact_ht[MY_TAB_SIZE];
44 static DEFINE_RWLOCK(gact_lock);
45 
46 /* ovewrride the defaults */
47 #define tcf_st		tcf_gact
48 #define tc_st		tc_gact
49 #define tcf_t_lock	gact_lock
50 #define tcf_ht		tcf_gact_ht
51 
52 #define CONFIG_NET_ACT_INIT 1
53 #include <net/pkt_act.h>
54 
55 #ifdef CONFIG_GACT_PROB
56 static int gact_net_rand(struct tcf_gact *p)
57 {
58 	if (net_random()%p->pval)
59 		return p->action;
60 	return p->paction;
61 }
62 
63 static int gact_determ(struct tcf_gact *p)
64 {
65 	if (p->bstats.packets%p->pval)
66 		return p->action;
67 	return p->paction;
68 }
69 
70 typedef int (*g_rand)(struct tcf_gact *p);
71 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
72 #endif
73 
74 static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
75                          struct tc_action *a, int ovr, int bind)
76 {
77 	struct rtattr *tb[TCA_GACT_MAX];
78 	struct tc_gact *parm;
79 	struct tcf_gact *p;
80 	int ret = 0;
81 
82 	if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
83 		return -EINVAL;
84 
85 	if (tb[TCA_GACT_PARMS - 1] == NULL ||
86 	    RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
87 		return -EINVAL;
88 	parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);
89 
90 	if (tb[TCA_GACT_PROB-1] != NULL)
91 #ifdef CONFIG_GACT_PROB
92 		if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
93 			return -EINVAL;
94 #else
95 		return -EOPNOTSUPP;
96 #endif
97 
98 	p = tcf_hash_check(parm->index, a, ovr, bind);
99 	if (p == NULL) {
100 		p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
101 		if (p == NULL)
102 			return -ENOMEM;
103 		ret = ACT_P_CREATED;
104 	} else {
105 		if (!ovr) {
106 			tcf_hash_release(p, bind);
107 			return -EEXIST;
108 		}
109 	}
110 
111 	spin_lock_bh(&p->lock);
112 	p->action = parm->action;
113 #ifdef CONFIG_GACT_PROB
114 	if (tb[TCA_GACT_PROB-1] != NULL) {
115 		struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
116 		p->paction = p_parm->paction;
117 		p->pval    = p_parm->pval;
118 		p->ptype   = p_parm->ptype;
119 	}
120 #endif
121 	spin_unlock_bh(&p->lock);
122 	if (ret == ACT_P_CREATED)
123 		tcf_hash_insert(p);
124 	return ret;
125 }
126 
127 static int
128 tcf_gact_cleanup(struct tc_action *a, int bind)
129 {
130 	struct tcf_gact *p = PRIV(a, gact);
131 
132 	if (p != NULL)
133 		return tcf_hash_release(p, bind);
134 	return 0;
135 }
136 
137 static int
138 tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
139 {
140 	struct tcf_gact *p = PRIV(a, gact);
141 	int action = TC_ACT_SHOT;
142 
143 	spin_lock(&p->lock);
144 #ifdef CONFIG_GACT_PROB
145 	if (p->ptype && gact_rand[p->ptype] != NULL)
146 		action = gact_rand[p->ptype](p);
147 	else
148 		action = p->action;
149 #else
150 	action = p->action;
151 #endif
152 	p->bstats.bytes += skb->len;
153 	p->bstats.packets++;
154 	if (action == TC_ACT_SHOT)
155 		p->qstats.drops++;
156 	p->tm.lastuse = jiffies;
157 	spin_unlock(&p->lock);
158 
159 	return action;
160 }
161 
162 static int
163 tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
164 {
165 	unsigned char *b = skb->tail;
166 	struct tc_gact opt;
167 	struct tcf_gact *p = PRIV(a, gact);
168 	struct tcf_t t;
169 
170 	opt.index = p->index;
171 	opt.refcnt = p->refcnt - ref;
172 	opt.bindcnt = p->bindcnt - bind;
173 	opt.action = p->action;
174 	RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
175 #ifdef CONFIG_GACT_PROB
176 	if (p->ptype) {
177 		struct tc_gact_p p_opt;
178 		p_opt.paction = p->paction;
179 		p_opt.pval = p->pval;
180 		p_opt.ptype = p->ptype;
181 		RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
182 	}
183 #endif
184 	t.install = jiffies_to_clock_t(jiffies - p->tm.install);
185 	t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
186 	t.expires = jiffies_to_clock_t(p->tm.expires);
187 	RTA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
188 	return skb->len;
189 
190       rtattr_failure:
191 	skb_trim(skb, b - skb->data);
192 	return -1;
193 }
194 
195 static struct tc_action_ops act_gact_ops = {
196 	.kind		=	"gact",
197 	.type		=	TCA_ACT_GACT,
198 	.capab		=	TCA_CAP_NONE,
199 	.owner		=	THIS_MODULE,
200 	.act		=	tcf_gact,
201 	.dump		=	tcf_gact_dump,
202 	.cleanup	=	tcf_gact_cleanup,
203 	.lookup		=	tcf_hash_search,
204 	.init		=	tcf_gact_init,
205 	.walk		=	tcf_generic_walker
206 };
207 
208 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
209 MODULE_DESCRIPTION("Generic Classifier actions");
210 MODULE_LICENSE("GPL");
211 
212 static int __init
213 gact_init_module(void)
214 {
215 #ifdef CONFIG_GACT_PROB
216 	printk("GACT probability on\n");
217 #else
218 	printk("GACT probability NOT on\n");
219 #endif
220 	return tcf_register_action(&act_gact_ops);
221 }
222 
223 static void __exit
224 gact_cleanup_module(void)
225 {
226 	tcf_unregister_action(&act_gact_ops);
227 }
228 
229 module_init(gact_init_module);
230 module_exit(gact_cleanup_module);
231