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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_FRAG_H__
3#define __NET_FRAG_H__
4
5#include <linux/rhashtable-types.h>
6
7struct netns_frags {
8 /* sysctls */
9 long high_thresh;
10 long low_thresh;
11 int timeout;
12 int max_dist;
13 struct inet_frags *f;
14
15 struct rhashtable rhashtable ____cacheline_aligned_in_smp;
16
17 /* Keep atomic mem on separate cachelines in structs that include it */
18 atomic_long_t mem ____cacheline_aligned_in_smp;
19};
20
21/**
22 * fragment queue flags
23 *
24 * @INET_FRAG_FIRST_IN: first fragment has arrived
25 * @INET_FRAG_LAST_IN: final fragment has arrived
26 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
27 */
28enum {
29 INET_FRAG_FIRST_IN = BIT(0),
30 INET_FRAG_LAST_IN = BIT(1),
31 INET_FRAG_COMPLETE = BIT(2),
32};
33
34struct frag_v4_compare_key {
35 __be32 saddr;
36 __be32 daddr;
37 u32 user;
38 u32 vif;
39 __be16 id;
40 u16 protocol;
41};
42
43struct frag_v6_compare_key {
44 struct in6_addr saddr;
45 struct in6_addr daddr;
46 u32 user;
47 __be32 id;
48 u32 iif;
49};
50
51/**
52 * struct inet_frag_queue - fragment queue
53 *
54 * @node: rhash node
55 * @key: keys identifying this frag.
56 * @timer: queue expiration timer
57 * @lock: spinlock protecting this frag
58 * @refcnt: reference count of the queue
59 * @rb_fragments: received fragments rb-tree root
60 * @fragments_tail: received fragments tail
61 * @last_run_head: the head of the last "run". see ip_fragment.c
62 * @stamp: timestamp of the last received fragment
63 * @len: total length of the original datagram
64 * @meat: length of received fragments so far
65 * @flags: fragment queue flags
66 * @max_size: maximum received fragment size
67 * @net: namespace that this frag belongs to
68 * @rcu: rcu head for freeing deferall
69 */
70struct inet_frag_queue {
71 struct rhash_head node;
72 union {
73 struct frag_v4_compare_key v4;
74 struct frag_v6_compare_key v6;
75 } key;
76 struct timer_list timer;
77 spinlock_t lock;
78 refcount_t refcnt;
79 struct rb_root rb_fragments;
80 struct sk_buff *fragments_tail;
81 struct sk_buff *last_run_head;
82 ktime_t stamp;
83 int len;
84 int meat;
85 __u8 flags;
86 u16 max_size;
87 struct netns_frags *net;
88 struct rcu_head rcu;
89};
90
91struct inet_frags {
92 unsigned int qsize;
93
94 void (*constructor)(struct inet_frag_queue *q,
95 const void *arg);
96 void (*destructor)(struct inet_frag_queue *);
97 void (*frag_expire)(struct timer_list *t);
98 struct kmem_cache *frags_cachep;
99 const char *frags_cache_name;
100 struct rhashtable_params rhash_params;
101};
102
103int inet_frags_init(struct inet_frags *);
104void inet_frags_fini(struct inet_frags *);
105
106static inline int inet_frags_init_net(struct netns_frags *nf)
107{
108 atomic_long_set(&nf->mem, 0);
109 return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params);
110}
111void inet_frags_exit_net(struct netns_frags *nf);
112
113void inet_frag_kill(struct inet_frag_queue *q);
114void inet_frag_destroy(struct inet_frag_queue *q);
115struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key);
116
117/* Free all skbs in the queue; return the sum of their truesizes. */
118unsigned int inet_frag_rbtree_purge(struct rb_root *root);
119
120static inline void inet_frag_put(struct inet_frag_queue *q)
121{
122 if (refcount_dec_and_test(&q->refcnt))
123 inet_frag_destroy(q);
124}
125
126/* Memory Tracking Functions. */
127
128static inline long frag_mem_limit(const struct netns_frags *nf)
129{
130 return atomic_long_read(&nf->mem);
131}
132
133static inline void sub_frag_mem_limit(struct netns_frags *nf, long val)
134{
135 atomic_long_sub(val, &nf->mem);
136}
137
138static inline void add_frag_mem_limit(struct netns_frags *nf, long val)
139{
140 atomic_long_add(val, &nf->mem);
141}
142
143/* RFC 3168 support :
144 * We want to check ECN values of all fragments, do detect invalid combinations.
145 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
146 */
147#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
148#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
149#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
150#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
151
152extern const u8 ip_frag_ecn_table[16];
153
154/* Return values of inet_frag_queue_insert() */
155#define IPFRAG_OK 0
156#define IPFRAG_DUP 1
157#define IPFRAG_OVERLAP 2
158int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
159 int offset, int end);
160void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
161 struct sk_buff *parent);
162void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
163 void *reasm_data);
164struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
165
166#endif