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70b095c8 FW |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _IPV6_FRAG_H | |
3 | #define _IPV6_FRAG_H | |
c78b8b20 | 4 | #include <linux/icmpv6.h> |
70b095c8 FW |
5 | #include <linux/kernel.h> |
6 | #include <net/addrconf.h> | |
7 | #include <net/ipv6.h> | |
8 | #include <net/inet_frag.h> | |
9 | ||
10 | enum ip6_defrag_users { | |
11 | IP6_DEFRAG_LOCAL_DELIVER, | |
12 | IP6_DEFRAG_CONNTRACK_IN, | |
13 | __IP6_DEFRAG_CONNTRACK_IN = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX, | |
14 | IP6_DEFRAG_CONNTRACK_OUT, | |
15 | __IP6_DEFRAG_CONNTRACK_OUT = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX, | |
16 | IP6_DEFRAG_CONNTRACK_BRIDGE_IN, | |
17 | __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, | |
18 | }; | |
19 | ||
20 | /* | |
21 | * Equivalent of ipv4 struct ip | |
22 | */ | |
23 | struct frag_queue { | |
24 | struct inet_frag_queue q; | |
25 | ||
26 | int iif; | |
27 | __u16 nhoffset; | |
28 | u8 ecn; | |
29 | }; | |
30 | ||
31 | #if IS_ENABLED(CONFIG_IPV6) | |
32 | static inline void ip6frag_init(struct inet_frag_queue *q, const void *a) | |
33 | { | |
34 | struct frag_queue *fq = container_of(q, struct frag_queue, q); | |
35 | const struct frag_v6_compare_key *key = a; | |
36 | ||
37 | q->key.v6 = *key; | |
38 | fq->ecn = 0; | |
39 | } | |
40 | ||
41 | static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed) | |
42 | { | |
43 | return jhash2(data, | |
44 | sizeof(struct frag_v6_compare_key) / sizeof(u32), seed); | |
45 | } | |
46 | ||
47 | static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed) | |
48 | { | |
49 | const struct inet_frag_queue *fq = data; | |
50 | ||
51 | return jhash2((const u32 *)&fq->key.v6, | |
52 | sizeof(struct frag_v6_compare_key) / sizeof(u32), seed); | |
53 | } | |
54 | ||
55 | static inline int | |
56 | ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr) | |
57 | { | |
58 | const struct frag_v6_compare_key *key = arg->key; | |
59 | const struct inet_frag_queue *fq = ptr; | |
60 | ||
61 | return !!memcmp(&fq->key, key, sizeof(*key)); | |
62 | } | |
63 | ||
64 | static inline void | |
65 | ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq) | |
66 | { | |
67 | struct net_device *dev = NULL; | |
68 | struct sk_buff *head; | |
69 | ||
70 | rcu_read_lock(); | |
91341fa0 ED |
71 | /* Paired with the WRITE_ONCE() in fqdir_pre_exit(). */ |
72 | if (READ_ONCE(fq->q.fqdir->dead)) | |
d5dd8879 | 73 | goto out_rcu_unlock; |
70b095c8 FW |
74 | spin_lock(&fq->q.lock); |
75 | ||
76 | if (fq->q.flags & INET_FRAG_COMPLETE) | |
77 | goto out; | |
78 | ||
77adfd3a | 79 | fq->q.flags |= INET_FRAG_DROP; |
70b095c8 FW |
80 | inet_frag_kill(&fq->q); |
81 | ||
82 | dev = dev_get_by_index_rcu(net, fq->iif); | |
83 | if (!dev) | |
84 | goto out; | |
85 | ||
86 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
87 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); | |
88 | ||
89 | /* Don't send error if the first segment did not arrive. */ | |
d4289fcc PO |
90 | if (!(fq->q.flags & INET_FRAG_FIRST_IN)) |
91 | goto out; | |
92 | ||
93 | /* sk_buff::dev and sk_buff::rbnode are unionized. So we | |
94 | * pull the head out of the tree in order to be able to | |
95 | * deal with head->dev. | |
96 | */ | |
97 | head = inet_frag_pull_head(&fq->q); | |
98 | if (!head) | |
70b095c8 FW |
99 | goto out; |
100 | ||
101 | head->dev = dev; | |
70b095c8 FW |
102 | spin_unlock(&fq->q.lock); |
103 | ||
104 | icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); | |
77adfd3a | 105 | kfree_skb_reason(head, SKB_DROP_REASON_FRAG_REASM_TIMEOUT); |
70b095c8 FW |
106 | goto out_rcu_unlock; |
107 | ||
108 | out: | |
109 | spin_unlock(&fq->q.lock); | |
110 | out_rcu_unlock: | |
111 | rcu_read_unlock(); | |
112 | inet_frag_put(&fq->q); | |
113 | } | |
2d8f6481 GK |
114 | |
115 | /* Check if the upper layer header is truncated in the first fragment. */ | |
116 | static inline bool | |
117 | ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp) | |
118 | { | |
119 | u8 nexthdr = *nexthdrp; | |
120 | __be16 frag_off; | |
121 | int offset; | |
122 | ||
123 | offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off); | |
124 | if (offset < 0 || (frag_off & htons(IP6_OFFSET))) | |
125 | return false; | |
126 | switch (nexthdr) { | |
127 | case NEXTHDR_TCP: | |
128 | offset += sizeof(struct tcphdr); | |
129 | break; | |
130 | case NEXTHDR_UDP: | |
131 | offset += sizeof(struct udphdr); | |
132 | break; | |
133 | case NEXTHDR_ICMP: | |
134 | offset += sizeof(struct icmp6hdr); | |
135 | break; | |
136 | default: | |
137 | offset += 1; | |
138 | } | |
139 | if (offset > skb->len) | |
140 | return true; | |
141 | return false; | |
142 | } | |
143 | ||
70b095c8 FW |
144 | #endif |
145 | #endif |