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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};
25
26/**
27 * fragment queue flags
28 *
29 * @INET_FRAG_FIRST_IN: first fragment has arrived
30 * @INET_FRAG_LAST_IN: final fragment has arrived
31 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
32 * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable
33 */
34enum {
35 INET_FRAG_FIRST_IN = BIT(0),
36 INET_FRAG_LAST_IN = BIT(1),
37 INET_FRAG_COMPLETE = BIT(2),
38 INET_FRAG_HASH_DEAD = BIT(3),
39};
40
41struct frag_v4_compare_key {
42 __be32 saddr;
43 __be32 daddr;
44 u32 user;
45 u32 vif;
46 __be16 id;
47 u16 protocol;
48};
49
50struct frag_v6_compare_key {
51 struct in6_addr saddr;
52 struct in6_addr daddr;
53 u32 user;
54 __be32 id;
55 u32 iif;
56};
57
58/**
59 * struct inet_frag_queue - fragment queue
60 *
61 * @node: rhash node
62 * @key: keys identifying this frag.
63 * @timer: queue expiration timer
64 * @lock: spinlock protecting this frag
65 * @refcnt: reference count of the queue
66 * @rb_fragments: received fragments rb-tree root
67 * @fragments_tail: received fragments tail
68 * @last_run_head: the head of the last "run". see ip_fragment.c
69 * @stamp: timestamp of the last received fragment
70 * @len: total length of the original datagram
71 * @meat: length of received fragments so far
72 * @flags: fragment queue flags
73 * @max_size: maximum received fragment size
74 * @fqdir: pointer to struct fqdir
75 * @rcu: rcu head for freeing deferall
76 */
77struct inet_frag_queue {
78 struct rhash_head node;
79 union {
80 struct frag_v4_compare_key v4;
81 struct frag_v6_compare_key v6;
82 } key;
83 struct timer_list timer;
84 spinlock_t lock;
85 refcount_t refcnt;
86 struct rb_root rb_fragments;
87 struct sk_buff *fragments_tail;
88 struct sk_buff *last_run_head;
89 ktime_t stamp;
90 int len;
91 int meat;
92 __u8 flags;
93 u16 max_size;
94 struct fqdir *fqdir;
95 struct rcu_head rcu;
96};
97
98struct inet_frags {
99 unsigned int qsize;
100
101 void (*constructor)(struct inet_frag_queue *q,
102 const void *arg);
103 void (*destructor)(struct inet_frag_queue *);
104 void (*frag_expire)(struct timer_list *t);
105 struct kmem_cache *frags_cachep;
106 const char *frags_cache_name;
107 struct rhashtable_params rhash_params;
108 refcount_t refcnt;
109 struct completion completion;
110};
111
112int inet_frags_init(struct inet_frags *);
113void inet_frags_fini(struct inet_frags *);
114
115int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
116
117static inline void fqdir_pre_exit(struct fqdir *fqdir)
118{
119 fqdir->high_thresh = 0; /* prevent creation of new frags */
120 fqdir->dead = true;
121}
122void fqdir_exit(struct fqdir *fqdir);
123
124void inet_frag_kill(struct inet_frag_queue *q);
125void inet_frag_destroy(struct inet_frag_queue *q);
126struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
127
128/* Free all skbs in the queue; return the sum of their truesizes. */
129unsigned int inet_frag_rbtree_purge(struct rb_root *root);
130
131static inline void inet_frag_put(struct inet_frag_queue *q)
132{
133 if (refcount_dec_and_test(&q->refcnt))
134 inet_frag_destroy(q);
135}
136
137/* Memory Tracking Functions. */
138
139static inline long frag_mem_limit(const struct fqdir *fqdir)
140{
141 return atomic_long_read(&fqdir->mem);
142}
143
144static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
145{
146 atomic_long_sub(val, &fqdir->mem);
147}
148
149static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
150{
151 atomic_long_add(val, &fqdir->mem);
152}
153
154/* RFC 3168 support :
155 * We want to check ECN values of all fragments, do detect invalid combinations.
156 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
157 */
158#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
159#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
160#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
161#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
162
163extern const u8 ip_frag_ecn_table[16];
164
165/* Return values of inet_frag_queue_insert() */
166#define IPFRAG_OK 0
167#define IPFRAG_DUP 1
168#define IPFRAG_OVERLAP 2
169int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
170 int offset, int end);
171void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
172 struct sk_buff *parent);
173void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
174 void *reasm_data, bool try_coalesce);
175struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
176
177#endif
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#include <linux/in6.h>
8#include <linux/rbtree_types.h>
9#include <linux/refcount.h>
10#include <net/dropreason-core.h>
11
12/* Per netns frag queues directory */
13struct fqdir {
14 /* sysctls */
15 long high_thresh;
16 long low_thresh;
17 int timeout;
18 int max_dist;
19 struct inet_frags *f;
20 struct net *net;
21 bool dead;
22
23 struct rhashtable rhashtable ____cacheline_aligned_in_smp;
24
25 /* Keep atomic mem on separate cachelines in structs that include it */
26 atomic_long_t mem ____cacheline_aligned_in_smp;
27 struct work_struct destroy_work;
28 struct llist_node free_list;
29};
30
31/**
32 * enum: fragment queue flags
33 *
34 * @INET_FRAG_FIRST_IN: first fragment has arrived
35 * @INET_FRAG_LAST_IN: final fragment has arrived
36 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
37 * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable
38 * @INET_FRAG_DROP: if skbs must be dropped (instead of being consumed)
39 */
40enum {
41 INET_FRAG_FIRST_IN = BIT(0),
42 INET_FRAG_LAST_IN = BIT(1),
43 INET_FRAG_COMPLETE = BIT(2),
44 INET_FRAG_HASH_DEAD = BIT(3),
45 INET_FRAG_DROP = BIT(4),
46};
47
48struct frag_v4_compare_key {
49 __be32 saddr;
50 __be32 daddr;
51 u32 user;
52 u32 vif;
53 __be16 id;
54 u16 protocol;
55};
56
57struct frag_v6_compare_key {
58 struct in6_addr saddr;
59 struct in6_addr daddr;
60 u32 user;
61 __be32 id;
62 u32 iif;
63};
64
65/**
66 * struct inet_frag_queue - fragment queue
67 *
68 * @node: rhash node
69 * @key: keys identifying this frag.
70 * @timer: queue expiration timer
71 * @lock: spinlock protecting this frag
72 * @refcnt: reference count of the queue
73 * @rb_fragments: received fragments rb-tree root
74 * @fragments_tail: received fragments tail
75 * @last_run_head: the head of the last "run". see ip_fragment.c
76 * @stamp: timestamp of the last received fragment
77 * @len: total length of the original datagram
78 * @meat: length of received fragments so far
79 * @mono_delivery_time: stamp has a mono delivery time (EDT)
80 * @flags: fragment queue flags
81 * @max_size: maximum received fragment size
82 * @fqdir: pointer to struct fqdir
83 * @rcu: rcu head for freeing deferall
84 */
85struct inet_frag_queue {
86 struct rhash_head node;
87 union {
88 struct frag_v4_compare_key v4;
89 struct frag_v6_compare_key v6;
90 } key;
91 struct timer_list timer;
92 spinlock_t lock;
93 refcount_t refcnt;
94 struct rb_root rb_fragments;
95 struct sk_buff *fragments_tail;
96 struct sk_buff *last_run_head;
97 ktime_t stamp;
98 int len;
99 int meat;
100 u8 mono_delivery_time;
101 __u8 flags;
102 u16 max_size;
103 struct fqdir *fqdir;
104 struct rcu_head rcu;
105};
106
107struct inet_frags {
108 unsigned int qsize;
109
110 void (*constructor)(struct inet_frag_queue *q,
111 const void *arg);
112 void (*destructor)(struct inet_frag_queue *);
113 void (*frag_expire)(struct timer_list *t);
114 struct kmem_cache *frags_cachep;
115 const char *frags_cache_name;
116 struct rhashtable_params rhash_params;
117 refcount_t refcnt;
118 struct completion completion;
119};
120
121int inet_frags_init(struct inet_frags *);
122void inet_frags_fini(struct inet_frags *);
123
124int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
125
126static inline void fqdir_pre_exit(struct fqdir *fqdir)
127{
128 /* Prevent creation of new frags.
129 * Pairs with READ_ONCE() in inet_frag_find().
130 */
131 WRITE_ONCE(fqdir->high_thresh, 0);
132
133 /* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire()
134 * and ip6frag_expire_frag_queue().
135 */
136 WRITE_ONCE(fqdir->dead, true);
137}
138void fqdir_exit(struct fqdir *fqdir);
139
140void inet_frag_kill(struct inet_frag_queue *q);
141void inet_frag_destroy(struct inet_frag_queue *q);
142struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
143
144/* Free all skbs in the queue; return the sum of their truesizes. */
145unsigned int inet_frag_rbtree_purge(struct rb_root *root,
146 enum skb_drop_reason reason);
147
148static inline void inet_frag_put(struct inet_frag_queue *q)
149{
150 if (refcount_dec_and_test(&q->refcnt))
151 inet_frag_destroy(q);
152}
153
154/* Memory Tracking Functions. */
155
156static inline long frag_mem_limit(const struct fqdir *fqdir)
157{
158 return atomic_long_read(&fqdir->mem);
159}
160
161static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
162{
163 atomic_long_sub(val, &fqdir->mem);
164}
165
166static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
167{
168 atomic_long_add(val, &fqdir->mem);
169}
170
171/* RFC 3168 support :
172 * We want to check ECN values of all fragments, do detect invalid combinations.
173 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
174 */
175#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
176#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
177#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
178#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
179
180extern const u8 ip_frag_ecn_table[16];
181
182/* Return values of inet_frag_queue_insert() */
183#define IPFRAG_OK 0
184#define IPFRAG_DUP 1
185#define IPFRAG_OVERLAP 2
186int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
187 int offset, int end);
188void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
189 struct sk_buff *parent);
190void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
191 void *reasm_data, bool try_coalesce);
192struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
193
194#endif