xref: /linux/include/net/ipv6_frag.h (revision 63307d015b91e626c97bb82e88054af3d0b74643)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _IPV6_FRAG_H
3 #define _IPV6_FRAG_H
4 #include <linux/kernel.h>
5 #include <net/addrconf.h>
6 #include <net/ipv6.h>
7 #include <net/inet_frag.h>
8 
9 enum ip6_defrag_users {
10 	IP6_DEFRAG_LOCAL_DELIVER,
11 	IP6_DEFRAG_CONNTRACK_IN,
12 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
13 	IP6_DEFRAG_CONNTRACK_OUT,
14 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
15 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
16 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
17 };
18 
19 /*
20  *	Equivalent of ipv4 struct ip
21  */
22 struct frag_queue {
23 	struct inet_frag_queue	q;
24 
25 	int			iif;
26 	__u16			nhoffset;
27 	u8			ecn;
28 };
29 
30 #if IS_ENABLED(CONFIG_IPV6)
31 static inline void ip6frag_init(struct inet_frag_queue *q, const void *a)
32 {
33 	struct frag_queue *fq = container_of(q, struct frag_queue, q);
34 	const struct frag_v6_compare_key *key = a;
35 
36 	q->key.v6 = *key;
37 	fq->ecn = 0;
38 }
39 
40 static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed)
41 {
42 	return jhash2(data,
43 		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
44 }
45 
46 static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed)
47 {
48 	const struct inet_frag_queue *fq = data;
49 
50 	return jhash2((const u32 *)&fq->key.v6,
51 		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
52 }
53 
54 static inline int
55 ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
56 {
57 	const struct frag_v6_compare_key *key = arg->key;
58 	const struct inet_frag_queue *fq = ptr;
59 
60 	return !!memcmp(&fq->key, key, sizeof(*key));
61 }
62 
63 static inline void
64 ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq)
65 {
66 	struct net_device *dev = NULL;
67 	struct sk_buff *head;
68 
69 	rcu_read_lock();
70 	spin_lock(&fq->q.lock);
71 
72 	if (fq->q.flags & INET_FRAG_COMPLETE)
73 		goto out;
74 
75 	inet_frag_kill(&fq->q);
76 
77 	dev = dev_get_by_index_rcu(net, fq->iif);
78 	if (!dev)
79 		goto out;
80 
81 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
82 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
83 
84 	/* Don't send error if the first segment did not arrive. */
85 	if (!(fq->q.flags & INET_FRAG_FIRST_IN))
86 		goto out;
87 
88 	/* sk_buff::dev and sk_buff::rbnode are unionized. So we
89 	 * pull the head out of the tree in order to be able to
90 	 * deal with head->dev.
91 	 */
92 	head = inet_frag_pull_head(&fq->q);
93 	if (!head)
94 		goto out;
95 
96 	head->dev = dev;
97 	spin_unlock(&fq->q.lock);
98 
99 	icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
100 	kfree_skb(head);
101 	goto out_rcu_unlock;
102 
103 out:
104 	spin_unlock(&fq->q.lock);
105 out_rcu_unlock:
106 	rcu_read_unlock();
107 	inet_frag_put(&fq->q);
108 }
109 #endif
110 #endif
111