xref: /openbmc/linux/net/sched/act_simple.c (revision 64c70b1c)
1 /*
2  * net/sched/simp.c	Simple example of an action
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  * Authors:	Jamal Hadi Salim (2005)
10  *
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <linux/skbuff.h>
18 #include <linux/rtnetlink.h>
19 #include <net/netlink.h>
20 #include <net/pkt_sched.h>
21 
22 #define TCA_ACT_SIMP 22
23 
24 #include <linux/tc_act/tc_defact.h>
25 #include <net/tc_act/tc_defact.h>
26 
27 #define SIMP_TAB_MASK     7
28 static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1];
29 static u32 simp_idx_gen;
30 static DEFINE_RWLOCK(simp_lock);
31 
32 static struct tcf_hashinfo simp_hash_info = {
33 	.htab	=	tcf_simp_ht,
34 	.hmask	=	SIMP_TAB_MASK,
35 	.lock	=	&simp_lock,
36 };
37 
38 static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
39 {
40 	struct tcf_defact *d = a->priv;
41 
42 	spin_lock(&d->tcf_lock);
43 	d->tcf_tm.lastuse = jiffies;
44 	d->tcf_bstats.bytes += skb->len;
45 	d->tcf_bstats.packets++;
46 
47 	/* print policy string followed by _ then packet count
48 	 * Example if this was the 3rd packet and the string was "hello"
49 	 * then it would look like "hello_3" (without quotes)
50 	 **/
51 	printk("simple: %s_%d\n",
52 	       (char *)d->tcfd_defdata, d->tcf_bstats.packets);
53 	spin_unlock(&d->tcf_lock);
54 	return d->tcf_action;
55 }
56 
57 static int tcf_simp_release(struct tcf_defact *d, int bind)
58 {
59 	int ret = 0;
60 	if (d) {
61 		if (bind)
62 			d->tcf_bindcnt--;
63 		d->tcf_refcnt--;
64 		if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) {
65 			kfree(d->tcfd_defdata);
66 			tcf_hash_destroy(&d->common, &simp_hash_info);
67 			ret = 1;
68 		}
69 	}
70 	return ret;
71 }
72 
73 static int alloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
74 {
75 	d->tcfd_defdata = kmemdup(defdata, datalen, GFP_KERNEL);
76 	if (unlikely(!d->tcfd_defdata))
77 		return -ENOMEM;
78 	d->tcfd_datalen = datalen;
79 	return 0;
80 }
81 
82 static int realloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
83 {
84 	kfree(d->tcfd_defdata);
85 	return alloc_defdata(d, datalen, defdata);
86 }
87 
88 static int tcf_simp_init(struct rtattr *rta, struct rtattr *est,
89 			 struct tc_action *a, int ovr, int bind)
90 {
91 	struct rtattr *tb[TCA_DEF_MAX];
92 	struct tc_defact *parm;
93 	struct tcf_defact *d;
94 	struct tcf_common *pc;
95 	void *defdata;
96 	u32 datalen = 0;
97 	int ret = 0;
98 
99 	if (rta == NULL || rtattr_parse_nested(tb, TCA_DEF_MAX, rta) < 0)
100 		return -EINVAL;
101 
102 	if (tb[TCA_DEF_PARMS - 1] == NULL ||
103 	    RTA_PAYLOAD(tb[TCA_DEF_PARMS - 1]) < sizeof(*parm))
104 		return -EINVAL;
105 
106 	parm = RTA_DATA(tb[TCA_DEF_PARMS - 1]);
107 	defdata = RTA_DATA(tb[TCA_DEF_DATA - 1]);
108 	if (defdata == NULL)
109 		return -EINVAL;
110 
111 	datalen = RTA_PAYLOAD(tb[TCA_DEF_DATA - 1]);
112 	if (datalen <= 0)
113 		return -EINVAL;
114 
115 	pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info);
116 	if (!pc) {
117 		pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
118 				     &simp_idx_gen, &simp_hash_info);
119 		if (unlikely(!pc))
120 			return -ENOMEM;
121 
122 		d = to_defact(pc);
123 		ret = alloc_defdata(d, datalen, defdata);
124 		if (ret < 0) {
125 			kfree(pc);
126 			return ret;
127 		}
128 		ret = ACT_P_CREATED;
129 	} else {
130 		d = to_defact(pc);
131 		if (!ovr) {
132 			tcf_simp_release(d, bind);
133 			return -EEXIST;
134 		}
135 		realloc_defdata(d, datalen, defdata);
136 	}
137 
138 	spin_lock_bh(&d->tcf_lock);
139 	d->tcf_action = parm->action;
140 	spin_unlock_bh(&d->tcf_lock);
141 
142 	if (ret == ACT_P_CREATED)
143 		tcf_hash_insert(pc, &simp_hash_info);
144 	return ret;
145 }
146 
147 static inline int tcf_simp_cleanup(struct tc_action *a, int bind)
148 {
149 	struct tcf_defact *d = a->priv;
150 
151 	if (d)
152 		return tcf_simp_release(d, bind);
153 	return 0;
154 }
155 
156 static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
157 				int bind, int ref)
158 {
159 	unsigned char *b = skb_tail_pointer(skb);
160 	struct tcf_defact *d = a->priv;
161 	struct tc_defact opt;
162 	struct tcf_t t;
163 
164 	opt.index = d->tcf_index;
165 	opt.refcnt = d->tcf_refcnt - ref;
166 	opt.bindcnt = d->tcf_bindcnt - bind;
167 	opt.action = d->tcf_action;
168 	RTA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt);
169 	RTA_PUT(skb, TCA_DEF_DATA, d->tcfd_datalen, d->tcfd_defdata);
170 	t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
171 	t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
172 	t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
173 	RTA_PUT(skb, TCA_DEF_TM, sizeof(t), &t);
174 	return skb->len;
175 
176 rtattr_failure:
177 	nlmsg_trim(skb, b);
178 	return -1;
179 }
180 
181 static struct tc_action_ops act_simp_ops = {
182 	.kind		=	"simple",
183 	.hinfo		=	&simp_hash_info,
184 	.type		=	TCA_ACT_SIMP,
185 	.capab		=	TCA_CAP_NONE,
186 	.owner		=	THIS_MODULE,
187 	.act		=	tcf_simp,
188 	.dump		=	tcf_simp_dump,
189 	.cleanup	=	tcf_simp_cleanup,
190 	.init		=	tcf_simp_init,
191 	.walk		=	tcf_generic_walker,
192 };
193 
194 MODULE_AUTHOR("Jamal Hadi Salim(2005)");
195 MODULE_DESCRIPTION("Simple example action");
196 MODULE_LICENSE("GPL");
197 
198 static int __init simp_init_module(void)
199 {
200 	int ret = tcf_register_action(&act_simp_ops);
201 	if (!ret)
202 		printk("Simple TC action Loaded\n");
203 	return ret;
204 }
205 
206 static void __exit simp_cleanup_module(void)
207 {
208 	tcf_unregister_action(&act_simp_ops);
209 }
210 
211 module_init(simp_init_module);
212 module_exit(simp_cleanup_module);
213