1/* net/sched/sch_ingress.c - Ingress qdisc
2 *              This program is free software; you can redistribute it and/or
3 *              modify it under the terms of the GNU General Public License
4 *              as published by the Free Software Foundation; either version
5 *              2 of the License, or (at your option) any later version.
6 *
7 * Authors:     Jamal Hadi Salim 1999
8 */
9
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/list.h>
13#include <linux/skbuff.h>
14#include <linux/rtnetlink.h>
15#include <net/netlink.h>
16#include <net/pkt_sched.h>
17
18
19struct ingress_qdisc_data {
20	struct tcf_proto __rcu	*filter_list;
21};
22
23/* ------------------------- Class/flow operations ------------------------- */
24
25static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
26{
27	return NULL;
28}
29
30static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
31{
32	return TC_H_MIN(classid) + 1;
33}
34
35static unsigned long ingress_bind_filter(struct Qdisc *sch,
36					 unsigned long parent, u32 classid)
37{
38	return ingress_get(sch, classid);
39}
40
41static void ingress_put(struct Qdisc *sch, unsigned long cl)
42{
43}
44
45static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
46{
47}
48
49static struct tcf_proto __rcu **ingress_find_tcf(struct Qdisc *sch,
50						 unsigned long cl)
51{
52	struct ingress_qdisc_data *p = qdisc_priv(sch);
53
54	return &p->filter_list;
55}
56
57/* --------------------------- Qdisc operations ---------------------------- */
58
59static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
60{
61	struct ingress_qdisc_data *p = qdisc_priv(sch);
62	struct tcf_result res;
63	struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
64	int result;
65
66	result = tc_classify(skb, fl, &res);
67
68	qdisc_bstats_update(sch, skb);
69	switch (result) {
70	case TC_ACT_SHOT:
71		result = TC_ACT_SHOT;
72		qdisc_qstats_drop(sch);
73		break;
74	case TC_ACT_STOLEN:
75	case TC_ACT_QUEUED:
76		result = TC_ACT_STOLEN;
77		break;
78	case TC_ACT_RECLASSIFY:
79	case TC_ACT_OK:
80		skb->tc_index = TC_H_MIN(res.classid);
81	default:
82		result = TC_ACT_OK;
83		break;
84	}
85
86	return result;
87}
88
89/* ------------------------------------------------------------- */
90
91static int ingress_init(struct Qdisc *sch, struct nlattr *opt)
92{
93	net_inc_ingress_queue();
94
95	return 0;
96}
97
98static void ingress_destroy(struct Qdisc *sch)
99{
100	struct ingress_qdisc_data *p = qdisc_priv(sch);
101
102	tcf_destroy_chain(&p->filter_list);
103	net_dec_ingress_queue();
104}
105
106static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
107{
108	struct nlattr *nest;
109
110	nest = nla_nest_start(skb, TCA_OPTIONS);
111	if (nest == NULL)
112		goto nla_put_failure;
113	return nla_nest_end(skb, nest);
114
115nla_put_failure:
116	nla_nest_cancel(skb, nest);
117	return -1;
118}
119
120static const struct Qdisc_class_ops ingress_class_ops = {
121	.leaf		=	ingress_leaf,
122	.get		=	ingress_get,
123	.put		=	ingress_put,
124	.walk		=	ingress_walk,
125	.tcf_chain	=	ingress_find_tcf,
126	.bind_tcf	=	ingress_bind_filter,
127	.unbind_tcf	=	ingress_put,
128};
129
130static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
131	.cl_ops		=	&ingress_class_ops,
132	.id		=	"ingress",
133	.priv_size	=	sizeof(struct ingress_qdisc_data),
134	.enqueue	=	ingress_enqueue,
135	.init		=	ingress_init,
136	.destroy	=	ingress_destroy,
137	.dump		=	ingress_dump,
138	.owner		=	THIS_MODULE,
139};
140
141static int __init ingress_module_init(void)
142{
143	return register_qdisc(&ingress_qdisc_ops);
144}
145
146static void __exit ingress_module_exit(void)
147{
148	unregister_qdisc(&ingress_qdisc_ops);
149}
150
151module_init(ingress_module_init)
152module_exit(ingress_module_exit)
153MODULE_LICENSE("GPL");
154