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)
ip6frag_init(struct inet_frag_queue * q,const void * a)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
ip6frag_key_hashfn(const void * data,u32 len,u32 seed)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
ip6frag_obj_hashfn(const void * data,u32 len,u32 seed)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
ip6frag_obj_cmpfn(struct rhashtable_compare_arg * arg,const void * ptr)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
ip6frag_expire_frag_queue(struct net * net,struct frag_queue * fq)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 if (fq->q.fqdir->dead)
71 goto out_rcu_unlock;
72 spin_lock(&fq->q.lock);
73
74 if (fq->q.flags & INET_FRAG_COMPLETE)
75 goto out;
76
77 inet_frag_kill(&fq->q);
78
79 dev = dev_get_by_index_rcu(net, fq->iif);
80 if (!dev)
81 goto out;
82
83 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
84 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
85
86 /* Don't send error if the first segment did not arrive. */
87 if (!(fq->q.flags & INET_FRAG_FIRST_IN))
88 goto out;
89
90 /* sk_buff::dev and sk_buff::rbnode are unionized. So we
91 * pull the head out of the tree in order to be able to
92 * deal with head->dev.
93 */
94 head = inet_frag_pull_head(&fq->q);
95 if (!head)
96 goto out;
97
98 head->dev = dev;
99 spin_unlock(&fq->q.lock);
100
101 icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
102 kfree_skb(head);
103 goto out_rcu_unlock;
104
105 out:
106 spin_unlock(&fq->q.lock);
107 out_rcu_unlock:
108 rcu_read_unlock();
109 inet_frag_put(&fq->q);
110 }
111
112 /* Check if the upper layer header is truncated in the first fragment. */
113 static inline bool
ipv6frag_thdr_truncated(struct sk_buff * skb,int start,u8 * nexthdrp)114 ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp)
115 {
116 u8 nexthdr = *nexthdrp;
117 __be16 frag_off;
118 int offset;
119
120 offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off);
121 if (offset < 0 || (frag_off & htons(IP6_OFFSET)))
122 return false;
123 switch (nexthdr) {
124 case NEXTHDR_TCP:
125 offset += sizeof(struct tcphdr);
126 break;
127 case NEXTHDR_UDP:
128 offset += sizeof(struct udphdr);
129 break;
130 case NEXTHDR_ICMP:
131 offset += sizeof(struct icmp6hdr);
132 break;
133 default:
134 offset += 1;
135 }
136 if (offset > skb->len)
137 return true;
138 return false;
139 }
140
141 #endif
142 #endif
143