1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/act_connmark.c netfilter connmark retriever action
4 * skb mark is over-written
5 *
6 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
7 */
8
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/skbuff.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/pkt_cls.h>
15 #include <linux/ip.h>
16 #include <linux/ipv6.h>
17 #include <net/netlink.h>
18 #include <net/pkt_sched.h>
19 #include <net/act_api.h>
20 #include <net/pkt_cls.h>
21 #include <uapi/linux/tc_act/tc_connmark.h>
22 #include <net/tc_act/tc_connmark.h>
23
24 #include <net/netfilter/nf_conntrack.h>
25 #include <net/netfilter/nf_conntrack_core.h>
26 #include <net/netfilter/nf_conntrack_zones.h>
27
28 static unsigned int connmark_net_id;
29 static struct tc_action_ops act_connmark_ops;
30
tcf_connmark_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)31 static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a,
32 struct tcf_result *res)
33 {
34 const struct nf_conntrack_tuple_hash *thash;
35 struct nf_conntrack_tuple tuple;
36 enum ip_conntrack_info ctinfo;
37 struct tcf_connmark_info *ca = to_connmark(a);
38 struct nf_conntrack_zone zone;
39 struct nf_conn *c;
40 int proto;
41
42 spin_lock(&ca->tcf_lock);
43 tcf_lastuse_update(&ca->tcf_tm);
44 bstats_update(&ca->tcf_bstats, skb);
45
46 switch (skb_protocol(skb, true)) {
47 case htons(ETH_P_IP):
48 if (skb->len < sizeof(struct iphdr))
49 goto out;
50
51 proto = NFPROTO_IPV4;
52 break;
53 case htons(ETH_P_IPV6):
54 if (skb->len < sizeof(struct ipv6hdr))
55 goto out;
56
57 proto = NFPROTO_IPV6;
58 break;
59 default:
60 goto out;
61 }
62
63 c = nf_ct_get(skb, &ctinfo);
64 if (c) {
65 skb->mark = c->mark;
66 /* using overlimits stats to count how many packets marked */
67 ca->tcf_qstats.overlimits++;
68 goto out;
69 }
70
71 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
72 proto, ca->net, &tuple))
73 goto out;
74
75 zone.id = ca->zone;
76 zone.dir = NF_CT_DEFAULT_ZONE_DIR;
77
78 thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
79 if (!thash)
80 goto out;
81
82 c = nf_ct_tuplehash_to_ctrack(thash);
83 /* using overlimits stats to count how many packets marked */
84 ca->tcf_qstats.overlimits++;
85 skb->mark = c->mark;
86 nf_ct_put(c);
87
88 out:
89 spin_unlock(&ca->tcf_lock);
90 return ca->tcf_action;
91 }
92
93 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = {
94 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) },
95 };
96
tcf_connmark_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)97 static int tcf_connmark_init(struct net *net, struct nlattr *nla,
98 struct nlattr *est, struct tc_action **a,
99 struct tcf_proto *tp, u32 flags,
100 struct netlink_ext_ack *extack)
101 {
102 struct tc_action_net *tn = net_generic(net, connmark_net_id);
103 struct nlattr *tb[TCA_CONNMARK_MAX + 1];
104 bool bind = flags & TCA_ACT_FLAGS_BIND;
105 struct tcf_chain *goto_ch = NULL;
106 struct tcf_connmark_info *ci;
107 struct tc_connmark *parm;
108 int ret = 0, err;
109 u32 index;
110
111 if (!nla)
112 return -EINVAL;
113
114 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla,
115 connmark_policy, NULL);
116 if (ret < 0)
117 return ret;
118
119 if (!tb[TCA_CONNMARK_PARMS])
120 return -EINVAL;
121
122 parm = nla_data(tb[TCA_CONNMARK_PARMS]);
123 index = parm->index;
124 ret = tcf_idr_check_alloc(tn, &index, a, bind);
125 if (!ret) {
126 ret = tcf_idr_create(tn, index, est, a,
127 &act_connmark_ops, bind, false, 0);
128 if (ret) {
129 tcf_idr_cleanup(tn, index);
130 return ret;
131 }
132
133 ci = to_connmark(*a);
134 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
135 extack);
136 if (err < 0)
137 goto release_idr;
138 tcf_action_set_ctrlact(*a, parm->action, goto_ch);
139 ci->net = net;
140 ci->zone = parm->zone;
141
142 ret = ACT_P_CREATED;
143 } else if (ret > 0) {
144 ci = to_connmark(*a);
145 if (bind)
146 return 0;
147 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
148 tcf_idr_release(*a, bind);
149 return -EEXIST;
150 }
151 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
152 extack);
153 if (err < 0)
154 goto release_idr;
155 /* replacing action and zone */
156 spin_lock_bh(&ci->tcf_lock);
157 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
158 ci->zone = parm->zone;
159 spin_unlock_bh(&ci->tcf_lock);
160 if (goto_ch)
161 tcf_chain_put_by_act(goto_ch);
162 ret = 0;
163 }
164
165 return ret;
166 release_idr:
167 tcf_idr_release(*a, bind);
168 return err;
169 }
170
tcf_connmark_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)171 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,
172 int bind, int ref)
173 {
174 unsigned char *b = skb_tail_pointer(skb);
175 struct tcf_connmark_info *ci = to_connmark(a);
176 struct tc_connmark opt = {
177 .index = ci->tcf_index,
178 .refcnt = refcount_read(&ci->tcf_refcnt) - ref,
179 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
180 };
181 struct tcf_t t;
182
183 spin_lock_bh(&ci->tcf_lock);
184 opt.action = ci->tcf_action;
185 opt.zone = ci->zone;
186 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt))
187 goto nla_put_failure;
188
189 tcf_tm_dump(&t, &ci->tcf_tm);
190 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t,
191 TCA_CONNMARK_PAD))
192 goto nla_put_failure;
193 spin_unlock_bh(&ci->tcf_lock);
194
195 return skb->len;
196
197 nla_put_failure:
198 spin_unlock_bh(&ci->tcf_lock);
199 nlmsg_trim(skb, b);
200 return -1;
201 }
202
tcf_connmark_walker(struct net * net,struct sk_buff * skb,struct netlink_callback * cb,int type,const struct tc_action_ops * ops,struct netlink_ext_ack * extack)203 static int tcf_connmark_walker(struct net *net, struct sk_buff *skb,
204 struct netlink_callback *cb, int type,
205 const struct tc_action_ops *ops,
206 struct netlink_ext_ack *extack)
207 {
208 struct tc_action_net *tn = net_generic(net, connmark_net_id);
209
210 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
211 }
212
tcf_connmark_search(struct net * net,struct tc_action ** a,u32 index)213 static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index)
214 {
215 struct tc_action_net *tn = net_generic(net, connmark_net_id);
216
217 return tcf_idr_search(tn, a, index);
218 }
219
220 static struct tc_action_ops act_connmark_ops = {
221 .kind = "connmark",
222 .id = TCA_ID_CONNMARK,
223 .owner = THIS_MODULE,
224 .act = tcf_connmark_act,
225 .dump = tcf_connmark_dump,
226 .init = tcf_connmark_init,
227 .walk = tcf_connmark_walker,
228 .lookup = tcf_connmark_search,
229 .size = sizeof(struct tcf_connmark_info),
230 };
231
connmark_init_net(struct net * net)232 static __net_init int connmark_init_net(struct net *net)
233 {
234 struct tc_action_net *tn = net_generic(net, connmark_net_id);
235
236 return tc_action_net_init(net, tn, &act_connmark_ops);
237 }
238
connmark_exit_net(struct list_head * net_list)239 static void __net_exit connmark_exit_net(struct list_head *net_list)
240 {
241 tc_action_net_exit(net_list, connmark_net_id);
242 }
243
244 static struct pernet_operations connmark_net_ops = {
245 .init = connmark_init_net,
246 .exit_batch = connmark_exit_net,
247 .id = &connmark_net_id,
248 .size = sizeof(struct tc_action_net),
249 };
250
connmark_init_module(void)251 static int __init connmark_init_module(void)
252 {
253 return tcf_register_action(&act_connmark_ops, &connmark_net_ops);
254 }
255
connmark_cleanup_module(void)256 static void __exit connmark_cleanup_module(void)
257 {
258 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops);
259 }
260
261 module_init(connmark_init_module);
262 module_exit(connmark_cleanup_module);
263 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
264 MODULE_DESCRIPTION("Connection tracking mark restoring");
265 MODULE_LICENSE("GPL");
266