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 (2005-8)
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
30static 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
49static 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
55static 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
64static 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
74static 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
79static 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
135static 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
158nla_put_failure:
159	nlmsg_trim(skb, b);
160	return -1;
161}
162
163static 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
173MODULE_AUTHOR("Jamal Hadi Salim(2005)");
174MODULE_DESCRIPTION("Simple example action");
175MODULE_LICENSE("GPL");
176
177static 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
186static void __exit simp_cleanup_module(void)
187{
188	tcf_unregister_action(&act_simp_ops);
189}
190
191module_init(simp_init_module);
192module_exit(simp_cleanup_module);
193