xref: /openbmc/linux/net/sched/act_gact.c (revision 64c70b1c)
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
38 static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
39 static u32 gact_idx_gen;
40 static DEFINE_RWLOCK(gact_lock);
41 
42 static 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
49 static 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 
56 static 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 
63 typedef int (*g_rand)(struct tcf_gact *gact);
64 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
65 #endif /* CONFIG_GACT_PROB */
66 
67 static 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 
124 static 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 
133 static 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 
157 static 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 
184 rtattr_failure:
185 	nlmsg_trim(skb, b);
186 	return -1;
187 }
188 
189 static 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 
203 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
204 MODULE_DESCRIPTION("Generic Classifier actions");
205 MODULE_LICENSE("GPL");
206 
207 static 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 
217 static void __exit gact_cleanup_module(void)
218 {
219 	tcf_unregister_action(&act_gact_ops);
220 }
221 
222 module_init(gact_init_module);
223 module_exit(gact_cleanup_module);
224