Florian Westphal | 70b095c | 2018-07-14 01:14:01 +0200 | [diff] [blame] | 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(); |
Eric Dumazet | d5dd8879 | 2019-06-18 11:09:00 -0700 | [diff] [blame] | 70 | if (fq->q.fqdir->dead) |
| 71 | goto out_rcu_unlock; |
Florian Westphal | 70b095c | 2018-07-14 01:14:01 +0200 | [diff] [blame] | 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. */ |
Peter Oskolkov | d4289fc | 2019-01-22 10:02:51 -0800 | [diff] [blame] | 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) |
Florian Westphal | 70b095c | 2018-07-14 01:14:01 +0200 | [diff] [blame] | 96 | goto out; |
| 97 | |
| 98 | head->dev = dev; |
Florian Westphal | 70b095c | 2018-07-14 01:14:01 +0200 | [diff] [blame] | 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 | } |
Georg Kohmann | 2d8f648 | 2020-11-19 10:58:33 +0100 | [diff] [blame] | 111 | |
| 112 | /* Check if the upper layer header is truncated in the first fragment. */ |
| 113 | static inline bool |
| 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 | |
Florian Westphal | 70b095c | 2018-07-14 01:14:01 +0200 | [diff] [blame] | 141 | #endif |
| 142 | #endif |