1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _IPV6_FRAG_H
3*4882a593Smuzhiyun #define _IPV6_FRAG_H
4*4882a593Smuzhiyun #include <linux/kernel.h>
5*4882a593Smuzhiyun #include <net/addrconf.h>
6*4882a593Smuzhiyun #include <net/ipv6.h>
7*4882a593Smuzhiyun #include <net/inet_frag.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun enum ip6_defrag_users {
10*4882a593Smuzhiyun IP6_DEFRAG_LOCAL_DELIVER,
11*4882a593Smuzhiyun IP6_DEFRAG_CONNTRACK_IN,
12*4882a593Smuzhiyun __IP6_DEFRAG_CONNTRACK_IN = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
13*4882a593Smuzhiyun IP6_DEFRAG_CONNTRACK_OUT,
14*4882a593Smuzhiyun __IP6_DEFRAG_CONNTRACK_OUT = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
15*4882a593Smuzhiyun IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
16*4882a593Smuzhiyun __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
17*4882a593Smuzhiyun };
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun /*
20*4882a593Smuzhiyun * Equivalent of ipv4 struct ip
21*4882a593Smuzhiyun */
22*4882a593Smuzhiyun struct frag_queue {
23*4882a593Smuzhiyun struct inet_frag_queue q;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun int iif;
26*4882a593Smuzhiyun __u16 nhoffset;
27*4882a593Smuzhiyun u8 ecn;
28*4882a593Smuzhiyun };
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun #if IS_ENABLED(CONFIG_IPV6)
ip6frag_init(struct inet_frag_queue * q,const void * a)31*4882a593Smuzhiyun static inline void ip6frag_init(struct inet_frag_queue *q, const void *a)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun struct frag_queue *fq = container_of(q, struct frag_queue, q);
34*4882a593Smuzhiyun const struct frag_v6_compare_key *key = a;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun q->key.v6 = *key;
37*4882a593Smuzhiyun fq->ecn = 0;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
ip6frag_key_hashfn(const void * data,u32 len,u32 seed)40*4882a593Smuzhiyun static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun return jhash2(data,
43*4882a593Smuzhiyun sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
ip6frag_obj_hashfn(const void * data,u32 len,u32 seed)46*4882a593Smuzhiyun static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun const struct inet_frag_queue *fq = data;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun return jhash2((const u32 *)&fq->key.v6,
51*4882a593Smuzhiyun sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun static inline int
ip6frag_obj_cmpfn(struct rhashtable_compare_arg * arg,const void * ptr)55*4882a593Smuzhiyun ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
56*4882a593Smuzhiyun {
57*4882a593Smuzhiyun const struct frag_v6_compare_key *key = arg->key;
58*4882a593Smuzhiyun const struct inet_frag_queue *fq = ptr;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun return !!memcmp(&fq->key, key, sizeof(*key));
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun static inline void
ip6frag_expire_frag_queue(struct net * net,struct frag_queue * fq)64*4882a593Smuzhiyun ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq)
65*4882a593Smuzhiyun {
66*4882a593Smuzhiyun struct net_device *dev = NULL;
67*4882a593Smuzhiyun struct sk_buff *head;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun rcu_read_lock();
70*4882a593Smuzhiyun /* Paired with the WRITE_ONCE() in fqdir_pre_exit(). */
71*4882a593Smuzhiyun if (READ_ONCE(fq->q.fqdir->dead))
72*4882a593Smuzhiyun goto out_rcu_unlock;
73*4882a593Smuzhiyun spin_lock(&fq->q.lock);
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun if (fq->q.flags & INET_FRAG_COMPLETE)
76*4882a593Smuzhiyun goto out;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun inet_frag_kill(&fq->q);
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun dev = dev_get_by_index_rcu(net, fq->iif);
81*4882a593Smuzhiyun if (!dev)
82*4882a593Smuzhiyun goto out;
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
85*4882a593Smuzhiyun __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun /* Don't send error if the first segment did not arrive. */
88*4882a593Smuzhiyun if (!(fq->q.flags & INET_FRAG_FIRST_IN))
89*4882a593Smuzhiyun goto out;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun /* sk_buff::dev and sk_buff::rbnode are unionized. So we
92*4882a593Smuzhiyun * pull the head out of the tree in order to be able to
93*4882a593Smuzhiyun * deal with head->dev.
94*4882a593Smuzhiyun */
95*4882a593Smuzhiyun head = inet_frag_pull_head(&fq->q);
96*4882a593Smuzhiyun if (!head)
97*4882a593Smuzhiyun goto out;
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun head->dev = dev;
100*4882a593Smuzhiyun spin_unlock(&fq->q.lock);
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
103*4882a593Smuzhiyun kfree_skb(head);
104*4882a593Smuzhiyun goto out_rcu_unlock;
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun out:
107*4882a593Smuzhiyun spin_unlock(&fq->q.lock);
108*4882a593Smuzhiyun out_rcu_unlock:
109*4882a593Smuzhiyun rcu_read_unlock();
110*4882a593Smuzhiyun inet_frag_put(&fq->q);
111*4882a593Smuzhiyun }
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun /* Check if the upper layer header is truncated in the first fragment. */
114*4882a593Smuzhiyun static inline bool
ipv6frag_thdr_truncated(struct sk_buff * skb,int start,u8 * nexthdrp)115*4882a593Smuzhiyun ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp)
116*4882a593Smuzhiyun {
117*4882a593Smuzhiyun u8 nexthdr = *nexthdrp;
118*4882a593Smuzhiyun __be16 frag_off;
119*4882a593Smuzhiyun int offset;
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off);
122*4882a593Smuzhiyun if (offset < 0 || (frag_off & htons(IP6_OFFSET)))
123*4882a593Smuzhiyun return false;
124*4882a593Smuzhiyun switch (nexthdr) {
125*4882a593Smuzhiyun case NEXTHDR_TCP:
126*4882a593Smuzhiyun offset += sizeof(struct tcphdr);
127*4882a593Smuzhiyun break;
128*4882a593Smuzhiyun case NEXTHDR_UDP:
129*4882a593Smuzhiyun offset += sizeof(struct udphdr);
130*4882a593Smuzhiyun break;
131*4882a593Smuzhiyun case NEXTHDR_ICMP:
132*4882a593Smuzhiyun offset += sizeof(struct icmp6hdr);
133*4882a593Smuzhiyun break;
134*4882a593Smuzhiyun default:
135*4882a593Smuzhiyun offset += 1;
136*4882a593Smuzhiyun }
137*4882a593Smuzhiyun if (offset > skb->len)
138*4882a593Smuzhiyun return true;
139*4882a593Smuzhiyun return false;
140*4882a593Smuzhiyun }
141*4882a593Smuzhiyun
142*4882a593Smuzhiyun #endif
143*4882a593Smuzhiyun #endif
144