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Linux kernel mirror (for testing)
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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#include <linux/completion.h>
7
8/* Per netns frag queues directory */
9struct fqdir {
10 /* sysctls */
11 long high_thresh;
12 long low_thresh;
13 int timeout;
14 int max_dist;
15 struct inet_frags *f;
16 struct net *net;
17 bool dead;
18
19 struct rhashtable rhashtable ____cacheline_aligned_in_smp;
20
21 /* Keep atomic mem on separate cachelines in structs that include it */
22 atomic_long_t mem ____cacheline_aligned_in_smp;
23 struct work_struct destroy_work;
24 struct llist_node free_list;
25};
26
27/**
28 * fragment queue flags
29 *
30 * @INET_FRAG_FIRST_IN: first fragment has arrived
31 * @INET_FRAG_LAST_IN: final fragment has arrived
32 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
33 * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable
34 */
35enum {
36 INET_FRAG_FIRST_IN = BIT(0),
37 INET_FRAG_LAST_IN = BIT(1),
38 INET_FRAG_COMPLETE = BIT(2),
39 INET_FRAG_HASH_DEAD = BIT(3),
40};
41
42struct frag_v4_compare_key {
43 __be32 saddr;
44 __be32 daddr;
45 u32 user;
46 u32 vif;
47 __be16 id;
48 u16 protocol;
49};
50
51struct frag_v6_compare_key {
52 struct in6_addr saddr;
53 struct in6_addr daddr;
54 u32 user;
55 __be32 id;
56 u32 iif;
57};
58
59/**
60 * struct inet_frag_queue - fragment queue
61 *
62 * @node: rhash node
63 * @key: keys identifying this frag.
64 * @timer: queue expiration timer
65 * @lock: spinlock protecting this frag
66 * @refcnt: reference count of the queue
67 * @rb_fragments: received fragments rb-tree root
68 * @fragments_tail: received fragments tail
69 * @last_run_head: the head of the last "run". see ip_fragment.c
70 * @stamp: timestamp of the last received fragment
71 * @len: total length of the original datagram
72 * @meat: length of received fragments so far
73 * @mono_delivery_time: stamp has a mono delivery time (EDT)
74 * @flags: fragment queue flags
75 * @max_size: maximum received fragment size
76 * @fqdir: pointer to struct fqdir
77 * @rcu: rcu head for freeing deferall
78 */
79struct inet_frag_queue {
80 struct rhash_head node;
81 union {
82 struct frag_v4_compare_key v4;
83 struct frag_v6_compare_key v6;
84 } key;
85 struct timer_list timer;
86 spinlock_t lock;
87 refcount_t refcnt;
88 struct rb_root rb_fragments;
89 struct sk_buff *fragments_tail;
90 struct sk_buff *last_run_head;
91 ktime_t stamp;
92 int len;
93 int meat;
94 u8 mono_delivery_time;
95 __u8 flags;
96 u16 max_size;
97 struct fqdir *fqdir;
98 struct rcu_head rcu;
99};
100
101struct inet_frags {
102 unsigned int qsize;
103
104 void (*constructor)(struct inet_frag_queue *q,
105 const void *arg);
106 void (*destructor)(struct inet_frag_queue *);
107 void (*frag_expire)(struct timer_list *t);
108 struct kmem_cache *frags_cachep;
109 const char *frags_cache_name;
110 struct rhashtable_params rhash_params;
111 refcount_t refcnt;
112 struct completion completion;
113};
114
115int inet_frags_init(struct inet_frags *);
116void inet_frags_fini(struct inet_frags *);
117
118int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
119
120static inline void fqdir_pre_exit(struct fqdir *fqdir)
121{
122 /* Prevent creation of new frags.
123 * Pairs with READ_ONCE() in inet_frag_find().
124 */
125 WRITE_ONCE(fqdir->high_thresh, 0);
126
127 /* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire()
128 * and ip6frag_expire_frag_queue().
129 */
130 WRITE_ONCE(fqdir->dead, true);
131}
132void fqdir_exit(struct fqdir *fqdir);
133
134void inet_frag_kill(struct inet_frag_queue *q);
135void inet_frag_destroy(struct inet_frag_queue *q);
136struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
137
138/* Free all skbs in the queue; return the sum of their truesizes. */
139unsigned int inet_frag_rbtree_purge(struct rb_root *root);
140
141static inline void inet_frag_put(struct inet_frag_queue *q)
142{
143 if (refcount_dec_and_test(&q->refcnt))
144 inet_frag_destroy(q);
145}
146
147/* Memory Tracking Functions. */
148
149static inline long frag_mem_limit(const struct fqdir *fqdir)
150{
151 return atomic_long_read(&fqdir->mem);
152}
153
154static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
155{
156 atomic_long_sub(val, &fqdir->mem);
157}
158
159static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
160{
161 atomic_long_add(val, &fqdir->mem);
162}
163
164/* RFC 3168 support :
165 * We want to check ECN values of all fragments, do detect invalid combinations.
166 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
167 */
168#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
169#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
170#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
171#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
172
173extern const u8 ip_frag_ecn_table[16];
174
175/* Return values of inet_frag_queue_insert() */
176#define IPFRAG_OK 0
177#define IPFRAG_DUP 1
178#define IPFRAG_OVERLAP 2
179int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
180 int offset, int end);
181void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
182 struct sk_buff *parent);
183void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
184 void *reasm_data, bool try_coalesce);
185struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
186
187#endif