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
9enum 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 */
22struct 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)
31static 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
40static 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
46static 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
54static inline int
55ip6frag_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
63static inline void
64ip6frag_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	/* Paired with the WRITE_ONCE() in fqdir_pre_exit(). */
71	if (READ_ONCE(fq->q.fqdir->dead))
72		goto out_rcu_unlock;
73	spin_lock(&fq->q.lock);
74
75	if (fq->q.flags & INET_FRAG_COMPLETE)
76		goto out;
77
78	inet_frag_kill(&fq->q);
79
80	dev = dev_get_by_index_rcu(net, fq->iif);
81	if (!dev)
82		goto out;
83
84	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
85	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
86
87	/* Don't send error if the first segment did not arrive. */
88	if (!(fq->q.flags & INET_FRAG_FIRST_IN))
89		goto out;
90
91	/* sk_buff::dev and sk_buff::rbnode are unionized. So we
92	 * pull the head out of the tree in order to be able to
93	 * deal with head->dev.
94	 */
95	head = inet_frag_pull_head(&fq->q);
96	if (!head)
97		goto out;
98
99	head->dev = dev;
100	spin_unlock(&fq->q.lock);
101
102	icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
103	kfree_skb(head);
104	goto out_rcu_unlock;
105
106out:
107	spin_unlock(&fq->q.lock);
108out_rcu_unlock:
109	rcu_read_unlock();
110	inet_frag_put(&fq->q);
111}
112
113/* Check if the upper layer header is truncated in the first fragment. */
114static inline bool
115ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp)
116{
117	u8 nexthdr = *nexthdrp;
118	__be16 frag_off;
119	int offset;
120
121	offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off);
122	if (offset < 0 || (frag_off & htons(IP6_OFFSET)))
123		return false;
124	switch (nexthdr) {
125	case NEXTHDR_TCP:
126		offset += sizeof(struct tcphdr);
127		break;
128	case NEXTHDR_UDP:
129		offset += sizeof(struct udphdr);
130		break;
131	case NEXTHDR_ICMP:
132		offset += sizeof(struct icmp6hdr);
133		break;
134	default:
135		offset += 1;
136	}
137	if (offset > skb->len)
138		return true;
139	return false;
140}
141
142#endif
143#endif
144