1 /*
2 * net/sched/act_connmark.c netfilter connmark retriever action
3 * skb mark is over-written
4 *
5 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/skbuff.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/pkt_cls.h>
19 #include <linux/ip.h>
20 #include <linux/ipv6.h>
21 #include <net/netlink.h>
22 #include <net/pkt_sched.h>
23 #include <net/act_api.h>
24 #include <uapi/linux/tc_act/tc_connmark.h>
25 #include <net/tc_act/tc_connmark.h>
26
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_core.h>
29 #include <net/netfilter/nf_conntrack_zones.h>
30
31 #define CONNMARK_TAB_MASK 3
32
tcf_connmark(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)33 static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a,
34 struct tcf_result *res)
35 {
36 const struct nf_conntrack_tuple_hash *thash;
37 struct nf_conntrack_tuple tuple;
38 enum ip_conntrack_info ctinfo;
39 struct tcf_connmark_info *ca = a->priv;
40 struct nf_conntrack_zone zone;
41 struct nf_conn *c;
42 int proto;
43
44 spin_lock(&ca->tcf_lock);
45 ca->tcf_tm.lastuse = jiffies;
46 bstats_update(&ca->tcf_bstats, skb);
47
48 if (skb->protocol == htons(ETH_P_IP)) {
49 if (skb->len < sizeof(struct iphdr))
50 goto out;
51
52 proto = NFPROTO_IPV4;
53 } else if (skb->protocol == htons(ETH_P_IPV6)) {
54 if (skb->len < sizeof(struct ipv6hdr))
55 goto out;
56
57 proto = NFPROTO_IPV6;
58 } else {
59 goto out;
60 }
61
62 c = nf_ct_get(skb, &ctinfo);
63 if (c) {
64 skb->mark = c->mark;
65 /* using overlimits stats to count how many packets marked */
66 ca->tcf_qstats.overlimits++;
67 goto out;
68 }
69
70 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
71 proto, ca->net, &tuple))
72 goto out;
73
74 zone.id = ca->zone;
75 zone.dir = NF_CT_DEFAULT_ZONE_DIR;
76
77 thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
78 if (!thash)
79 goto out;
80
81 c = nf_ct_tuplehash_to_ctrack(thash);
82 /* using overlimits stats to count how many packets marked */
83 ca->tcf_qstats.overlimits++;
84 skb->mark = c->mark;
85 nf_ct_put(c);
86
87 out:
88 spin_unlock(&ca->tcf_lock);
89 return ca->tcf_action;
90 }
91
92 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = {
93 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) },
94 };
95
tcf_connmark_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action * a,int ovr,int bind)96 static int tcf_connmark_init(struct net *net, struct nlattr *nla,
97 struct nlattr *est, struct tc_action *a,
98 int ovr, int bind)
99 {
100 struct nlattr *tb[TCA_CONNMARK_MAX + 1];
101 struct tcf_connmark_info *ci;
102 struct tc_connmark *parm;
103 int ret = 0;
104
105 if (!nla)
106 return -EINVAL;
107
108 ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy);
109 if (ret < 0)
110 return ret;
111
112 if (!tb[TCA_CONNMARK_PARMS])
113 return -EINVAL;
114
115 parm = nla_data(tb[TCA_CONNMARK_PARMS]);
116
117 if (!tcf_hash_check(parm->index, a, bind)) {
118 ret = tcf_hash_create(parm->index, est, a, sizeof(*ci),
119 bind, false);
120 if (ret)
121 return ret;
122
123 ci = to_connmark(a);
124 ci->tcf_action = parm->action;
125 ci->net = net;
126 ci->zone = parm->zone;
127
128 tcf_hash_insert(a);
129 ret = ACT_P_CREATED;
130 } else {
131 ci = to_connmark(a);
132 if (bind)
133 return 0;
134 tcf_hash_release(a, bind);
135 if (!ovr)
136 return -EEXIST;
137 /* replacing action and zone */
138 ci->tcf_action = parm->action;
139 ci->zone = parm->zone;
140 }
141
142 return ret;
143 }
144
tcf_connmark_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)145 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,
146 int bind, int ref)
147 {
148 unsigned char *b = skb_tail_pointer(skb);
149 struct tcf_connmark_info *ci = a->priv;
150
151 struct tc_connmark opt = {
152 .index = ci->tcf_index,
153 .refcnt = ci->tcf_refcnt - ref,
154 .bindcnt = ci->tcf_bindcnt - bind,
155 .action = ci->tcf_action,
156 .zone = ci->zone,
157 };
158 struct tcf_t t;
159
160 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt))
161 goto nla_put_failure;
162
163 t.install = jiffies_to_clock_t(jiffies - ci->tcf_tm.install);
164 t.lastuse = jiffies_to_clock_t(jiffies - ci->tcf_tm.lastuse);
165 t.expires = jiffies_to_clock_t(ci->tcf_tm.expires);
166 if (nla_put(skb, TCA_CONNMARK_TM, sizeof(t), &t))
167 goto nla_put_failure;
168
169 return skb->len;
170 nla_put_failure:
171 nlmsg_trim(skb, b);
172 return -1;
173 }
174
175 static struct tc_action_ops act_connmark_ops = {
176 .kind = "connmark",
177 .type = TCA_ACT_CONNMARK,
178 .owner = THIS_MODULE,
179 .act = tcf_connmark,
180 .dump = tcf_connmark_dump,
181 .init = tcf_connmark_init,
182 };
183
connmark_init_module(void)184 static int __init connmark_init_module(void)
185 {
186 return tcf_register_action(&act_connmark_ops, CONNMARK_TAB_MASK);
187 }
188
connmark_cleanup_module(void)189 static void __exit connmark_cleanup_module(void)
190 {
191 tcf_unregister_action(&act_connmark_ops);
192 }
193
194 module_init(connmark_init_module);
195 module_exit(connmark_cleanup_module);
196 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
197 MODULE_DESCRIPTION("Connection tracking mark restoring");
198 MODULE_LICENSE("GPL");
199
200