1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _IPV6_FRAG_H 3 #define _IPV6_FRAG_H 4 #include <linux/icmpv6.h> 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(); 71 /* Paired with the WRITE_ONCE() in fqdir_pre_exit(). */ 72 if (READ_ONCE(fq->q.fqdir->dead)) 73 goto out_rcu_unlock; 74 spin_lock(&fq->q.lock); 75 76 if (fq->q.flags & INET_FRAG_COMPLETE) 77 goto out; 78 79 fq->q.flags |= INET_FRAG_DROP; 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. */ 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) 99 goto out; 100 101 head->dev = dev; 102 spin_unlock(&fq->q.lock); 103 104 icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 105 kfree_skb_reason(head, SKB_DROP_REASON_FRAG_REASM_TIMEOUT); 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 } 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 } 143 144 #endif 145 #endif 146