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 | #include <net/tc_wrapper.h> |
24 | |
25 | #include <net/netfilter/nf_conntrack.h> |
26 | #include <net/netfilter/nf_conntrack_core.h> |
27 | #include <net/netfilter/nf_conntrack_zones.h> |
28 | |
29 | static struct tc_action_ops act_connmark_ops; |
30 | |
31 | TC_INDIRECT_SCOPE int tcf_connmark_act(struct sk_buff *skb, |
32 | const struct tc_action *a, |
33 | struct tcf_result *res) |
34 | { |
35 | const struct nf_conntrack_tuple_hash *thash; |
36 | struct nf_conntrack_tuple tuple; |
37 | enum ip_conntrack_info ctinfo; |
38 | struct tcf_connmark_info *ca = to_connmark(a); |
39 | struct tcf_connmark_parms *parms; |
40 | struct nf_conntrack_zone zone; |
41 | struct nf_conn *c; |
42 | int proto; |
43 | |
44 | tcf_lastuse_update(tm: &ca->tcf_tm); |
45 | tcf_action_update_bstats(a: &ca->common, skb); |
46 | |
47 | parms = rcu_dereference_bh(ca->parms); |
48 | |
49 | switch (skb_protocol(skb, skip_vlan: true)) { |
50 | case htons(ETH_P_IP): |
51 | if (skb->len < sizeof(struct iphdr)) |
52 | goto out; |
53 | |
54 | proto = NFPROTO_IPV4; |
55 | break; |
56 | case htons(ETH_P_IPV6): |
57 | if (skb->len < sizeof(struct ipv6hdr)) |
58 | goto out; |
59 | |
60 | proto = NFPROTO_IPV6; |
61 | break; |
62 | default: |
63 | goto out; |
64 | } |
65 | |
66 | c = nf_ct_get(skb, ctinfo: &ctinfo); |
67 | if (c) { |
68 | skb->mark = READ_ONCE(c->mark); |
69 | goto count; |
70 | } |
71 | |
72 | if (!nf_ct_get_tuplepr(skb, nhoff: skb_network_offset(skb), l3num: proto, net: parms->net, |
73 | tuple: &tuple)) |
74 | goto out; |
75 | |
76 | zone.id = parms->zone; |
77 | zone.dir = NF_CT_DEFAULT_ZONE_DIR; |
78 | |
79 | thash = nf_conntrack_find_get(net: parms->net, zone: &zone, tuple: &tuple); |
80 | if (!thash) |
81 | goto out; |
82 | |
83 | c = nf_ct_tuplehash_to_ctrack(hash: thash); |
84 | skb->mark = READ_ONCE(c->mark); |
85 | nf_ct_put(ct: c); |
86 | |
87 | count: |
88 | /* using overlimits stats to count how many packets marked */ |
89 | tcf_action_inc_overlimit_qstats(a: &ca->common); |
90 | out: |
91 | return READ_ONCE(ca->tcf_action); |
92 | } |
93 | |
94 | static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { |
95 | [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, |
96 | }; |
97 | |
98 | static int tcf_connmark_init(struct net *net, struct nlattr *nla, |
99 | struct nlattr *est, struct tc_action **a, |
100 | struct tcf_proto *tp, u32 flags, |
101 | struct netlink_ext_ack *extack) |
102 | { |
103 | struct tc_action_net *tn = net_generic(net, id: act_connmark_ops.net_id); |
104 | struct tcf_connmark_parms *nparms, *oparms; |
105 | struct nlattr *tb[TCA_CONNMARK_MAX + 1]; |
106 | bool bind = flags & TCA_ACT_FLAGS_BIND; |
107 | struct tcf_chain *goto_ch = NULL; |
108 | struct tcf_connmark_info *ci; |
109 | struct tc_connmark *parm; |
110 | int ret = 0, err; |
111 | u32 index; |
112 | |
113 | if (!nla) |
114 | return -EINVAL; |
115 | |
116 | ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, |
117 | policy: connmark_policy, NULL); |
118 | if (ret < 0) |
119 | return ret; |
120 | |
121 | if (!tb[TCA_CONNMARK_PARMS]) |
122 | return -EINVAL; |
123 | |
124 | nparms = kzalloc(size: sizeof(*nparms), GFP_KERNEL); |
125 | if (!nparms) |
126 | return -ENOMEM; |
127 | |
128 | parm = nla_data(nla: tb[TCA_CONNMARK_PARMS]); |
129 | index = parm->index; |
130 | ret = tcf_idr_check_alloc(tn, index: &index, a, bind); |
131 | if (!ret) { |
132 | ret = tcf_idr_create_from_flags(tn, index, est, a, |
133 | ops: &act_connmark_ops, bind, flags); |
134 | if (ret) { |
135 | tcf_idr_cleanup(tn, index); |
136 | err = ret; |
137 | goto out_free; |
138 | } |
139 | |
140 | ci = to_connmark(*a); |
141 | |
142 | nparms->net = net; |
143 | nparms->zone = parm->zone; |
144 | |
145 | ret = ACT_P_CREATED; |
146 | } else if (ret > 0) { |
147 | ci = to_connmark(*a); |
148 | if (bind) { |
149 | err = 0; |
150 | goto out_free; |
151 | } |
152 | if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
153 | err = -EEXIST; |
154 | goto release_idr; |
155 | } |
156 | |
157 | nparms->net = rtnl_dereference(ci->parms)->net; |
158 | nparms->zone = parm->zone; |
159 | |
160 | ret = 0; |
161 | } else { |
162 | err = ret; |
163 | goto out_free; |
164 | } |
165 | |
166 | err = tcf_action_check_ctrlact(action: parm->action, tp, handle: &goto_ch, newchain: extack); |
167 | if (err < 0) |
168 | goto release_idr; |
169 | |
170 | spin_lock_bh(lock: &ci->tcf_lock); |
171 | goto_ch = tcf_action_set_ctrlact(a: *a, action: parm->action, newchain: goto_ch); |
172 | oparms = rcu_replace_pointer(ci->parms, nparms, lockdep_is_held(&ci->tcf_lock)); |
173 | spin_unlock_bh(lock: &ci->tcf_lock); |
174 | |
175 | if (goto_ch) |
176 | tcf_chain_put_by_act(chain: goto_ch); |
177 | |
178 | if (oparms) |
179 | kfree_rcu(oparms, rcu); |
180 | |
181 | return ret; |
182 | |
183 | release_idr: |
184 | tcf_idr_release(a: *a, bind); |
185 | out_free: |
186 | kfree(objp: nparms); |
187 | return err; |
188 | } |
189 | |
190 | static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, |
191 | int bind, int ref) |
192 | { |
193 | unsigned char *b = skb_tail_pointer(skb); |
194 | struct tcf_connmark_info *ci = to_connmark(a); |
195 | struct tc_connmark opt = { |
196 | .index = ci->tcf_index, |
197 | .refcnt = refcount_read(r: &ci->tcf_refcnt) - ref, |
198 | .bindcnt = atomic_read(v: &ci->tcf_bindcnt) - bind, |
199 | }; |
200 | struct tcf_connmark_parms *parms; |
201 | struct tcf_t t; |
202 | |
203 | spin_lock_bh(lock: &ci->tcf_lock); |
204 | parms = rcu_dereference_protected(ci->parms, lockdep_is_held(&ci->tcf_lock)); |
205 | |
206 | opt.action = ci->tcf_action; |
207 | opt.zone = parms->zone; |
208 | if (nla_put(skb, attrtype: TCA_CONNMARK_PARMS, attrlen: sizeof(opt), data: &opt)) |
209 | goto nla_put_failure; |
210 | |
211 | tcf_tm_dump(dtm: &t, stm: &ci->tcf_tm); |
212 | if (nla_put_64bit(skb, attrtype: TCA_CONNMARK_TM, attrlen: sizeof(t), data: &t, |
213 | padattr: TCA_CONNMARK_PAD)) |
214 | goto nla_put_failure; |
215 | spin_unlock_bh(lock: &ci->tcf_lock); |
216 | |
217 | return skb->len; |
218 | |
219 | nla_put_failure: |
220 | spin_unlock_bh(lock: &ci->tcf_lock); |
221 | nlmsg_trim(skb, mark: b); |
222 | return -1; |
223 | } |
224 | |
225 | static void tcf_connmark_cleanup(struct tc_action *a) |
226 | { |
227 | struct tcf_connmark_info *ci = to_connmark(a); |
228 | struct tcf_connmark_parms *parms; |
229 | |
230 | parms = rcu_dereference_protected(ci->parms, 1); |
231 | if (parms) |
232 | kfree_rcu(parms, rcu); |
233 | } |
234 | |
235 | static struct tc_action_ops act_connmark_ops = { |
236 | .kind = "connmark" , |
237 | .id = TCA_ID_CONNMARK, |
238 | .owner = THIS_MODULE, |
239 | .act = tcf_connmark_act, |
240 | .dump = tcf_connmark_dump, |
241 | .init = tcf_connmark_init, |
242 | .cleanup = tcf_connmark_cleanup, |
243 | .size = sizeof(struct tcf_connmark_info), |
244 | }; |
245 | |
246 | static __net_init int connmark_init_net(struct net *net) |
247 | { |
248 | struct tc_action_net *tn = net_generic(net, id: act_connmark_ops.net_id); |
249 | |
250 | return tc_action_net_init(net, tn, ops: &act_connmark_ops); |
251 | } |
252 | |
253 | static void __net_exit connmark_exit_net(struct list_head *net_list) |
254 | { |
255 | tc_action_net_exit(net_list, id: act_connmark_ops.net_id); |
256 | } |
257 | |
258 | static struct pernet_operations connmark_net_ops = { |
259 | .init = connmark_init_net, |
260 | .exit_batch = connmark_exit_net, |
261 | .id = &act_connmark_ops.net_id, |
262 | .size = sizeof(struct tc_action_net), |
263 | }; |
264 | |
265 | static int __init connmark_init_module(void) |
266 | { |
267 | return tcf_register_action(a: &act_connmark_ops, ops: &connmark_net_ops); |
268 | } |
269 | |
270 | static void __exit connmark_cleanup_module(void) |
271 | { |
272 | tcf_unregister_action(a: &act_connmark_ops, ops: &connmark_net_ops); |
273 | } |
274 | |
275 | module_init(connmark_init_module); |
276 | module_exit(connmark_cleanup_module); |
277 | MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>" ); |
278 | MODULE_DESCRIPTION("Connection tracking mark restoring" ); |
279 | MODULE_LICENSE("GPL" ); |
280 | |