xref: /openbmc/linux/net/sched/act_simple.c (revision c819e2cf)
1 /*
2  * net/sched/act_simple.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 (2005-8)
10  *
11  */
12 
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/kernel.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 
29 #define SIMP_MAX_DATA	32
30 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a,
31 		    struct tcf_result *res)
32 {
33 	struct tcf_defact *d = a->priv;
34 
35 	spin_lock(&d->tcf_lock);
36 	d->tcf_tm.lastuse = jiffies;
37 	bstats_update(&d->tcf_bstats, skb);
38 
39 	/* print policy string followed by _ then packet count
40 	 * Example if this was the 3rd packet and the string was "hello"
41 	 * then it would look like "hello_3" (without quotes)
42 	 */
43 	pr_info("simple: %s_%d\n",
44 	       (char *)d->tcfd_defdata, d->tcf_bstats.packets);
45 	spin_unlock(&d->tcf_lock);
46 	return d->tcf_action;
47 }
48 
49 static void tcf_simp_release(struct tc_action *a, int bind)
50 {
51 	struct tcf_defact *d = to_defact(a);
52 	kfree(d->tcfd_defdata);
53 }
54 
55 static int alloc_defdata(struct tcf_defact *d, char *defdata)
56 {
57 	d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
58 	if (unlikely(!d->tcfd_defdata))
59 		return -ENOMEM;
60 	strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
61 	return 0;
62 }
63 
64 static void reset_policy(struct tcf_defact *d, char *defdata,
65 			 struct tc_defact *p)
66 {
67 	spin_lock_bh(&d->tcf_lock);
68 	d->tcf_action = p->action;
69 	memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
70 	strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
71 	spin_unlock_bh(&d->tcf_lock);
72 }
73 
74 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
75 	[TCA_DEF_PARMS]	= { .len = sizeof(struct tc_defact) },
76 	[TCA_DEF_DATA]	= { .type = NLA_STRING, .len = SIMP_MAX_DATA },
77 };
78 
79 static int tcf_simp_init(struct net *net, struct nlattr *nla,
80 			 struct nlattr *est, struct tc_action *a,
81 			 int ovr, int bind)
82 {
83 	struct nlattr *tb[TCA_DEF_MAX + 1];
84 	struct tc_defact *parm;
85 	struct tcf_defact *d;
86 	char *defdata;
87 	int ret = 0, err;
88 
89 	if (nla == NULL)
90 		return -EINVAL;
91 
92 	err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy);
93 	if (err < 0)
94 		return err;
95 
96 	if (tb[TCA_DEF_PARMS] == NULL)
97 		return -EINVAL;
98 
99 	if (tb[TCA_DEF_DATA] == NULL)
100 		return -EINVAL;
101 
102 	parm = nla_data(tb[TCA_DEF_PARMS]);
103 	defdata = nla_data(tb[TCA_DEF_DATA]);
104 
105 	if (!tcf_hash_check(parm->index, a, bind)) {
106 		ret = tcf_hash_create(parm->index, est, a, sizeof(*d), bind);
107 		if (ret)
108 			return ret;
109 
110 		d = to_defact(a);
111 		ret = alloc_defdata(d, defdata);
112 		if (ret < 0) {
113 			tcf_hash_cleanup(a, est);
114 			return ret;
115 		}
116 		d->tcf_action = parm->action;
117 		ret = ACT_P_CREATED;
118 	} else {
119 		d = to_defact(a);
120 
121 		if (bind)
122 			return 0;
123 		tcf_hash_release(a, bind);
124 		if (!ovr)
125 			return -EEXIST;
126 
127 		reset_policy(d, defdata, parm);
128 	}
129 
130 	if (ret == ACT_P_CREATED)
131 		tcf_hash_insert(a);
132 	return ret;
133 }
134 
135 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
136 			 int bind, int ref)
137 {
138 	unsigned char *b = skb_tail_pointer(skb);
139 	struct tcf_defact *d = a->priv;
140 	struct tc_defact opt = {
141 		.index   = d->tcf_index,
142 		.refcnt  = d->tcf_refcnt - ref,
143 		.bindcnt = d->tcf_bindcnt - bind,
144 		.action  = d->tcf_action,
145 	};
146 	struct tcf_t t;
147 
148 	if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
149 	    nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
150 		goto nla_put_failure;
151 	t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
152 	t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
153 	t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
154 	if (nla_put(skb, TCA_DEF_TM, sizeof(t), &t))
155 		goto nla_put_failure;
156 	return skb->len;
157 
158 nla_put_failure:
159 	nlmsg_trim(skb, b);
160 	return -1;
161 }
162 
163 static struct tc_action_ops act_simp_ops = {
164 	.kind		=	"simple",
165 	.type		=	TCA_ACT_SIMP,
166 	.owner		=	THIS_MODULE,
167 	.act		=	tcf_simp,
168 	.dump		=	tcf_simp_dump,
169 	.cleanup	=	tcf_simp_release,
170 	.init		=	tcf_simp_init,
171 };
172 
173 MODULE_AUTHOR("Jamal Hadi Salim(2005)");
174 MODULE_DESCRIPTION("Simple example action");
175 MODULE_LICENSE("GPL");
176 
177 static int __init simp_init_module(void)
178 {
179 	int ret;
180 	ret = tcf_register_action(&act_simp_ops, SIMP_TAB_MASK);
181 	if (!ret)
182 		pr_info("Simple TC action Loaded\n");
183 	return ret;
184 }
185 
186 static void __exit simp_cleanup_module(void)
187 {
188 	tcf_unregister_action(&act_simp_ops);
189 }
190 
191 module_init(simp_init_module);
192 module_exit(simp_cleanup_module);
193