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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#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 * @tstamp_type: 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 tstamp_type;
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
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 * @flags: fragment queue flags
74 * @max_size: maximum received fragment size
75 * @fqdir: pointer to struct fqdir
76 * @rcu: rcu head for freeing deferall
77 */
78struct inet_frag_queue {
79 struct rhash_head node;
80 union {
81 struct frag_v4_compare_key v4;
82 struct frag_v6_compare_key v6;
83 } key;
84 struct timer_list timer;
85 spinlock_t lock;
86 refcount_t refcnt;
87 struct rb_root rb_fragments;
88 struct sk_buff *fragments_tail;
89 struct sk_buff *last_run_head;
90 ktime_t stamp;
91 int len;
92 int meat;
93 __u8 flags;
94 u16 max_size;
95 struct fqdir *fqdir;
96 struct rcu_head rcu;
97};
98
99struct inet_frags {
100 unsigned int qsize;
101
102 void (*constructor)(struct inet_frag_queue *q,
103 const void *arg);
104 void (*destructor)(struct inet_frag_queue *);
105 void (*frag_expire)(struct timer_list *t);
106 struct kmem_cache *frags_cachep;
107 const char *frags_cache_name;
108 struct rhashtable_params rhash_params;
109 refcount_t refcnt;
110 struct completion completion;
111};
112
113int inet_frags_init(struct inet_frags *);
114void inet_frags_fini(struct inet_frags *);
115
116int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
117
118static inline void fqdir_pre_exit(struct fqdir *fqdir)
119{
120 fqdir->high_thresh = 0; /* prevent creation of new frags */
121 fqdir->dead = true;
122}
123void fqdir_exit(struct fqdir *fqdir);
124
125void inet_frag_kill(struct inet_frag_queue *q);
126void inet_frag_destroy(struct inet_frag_queue *q);
127struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
128
129/* Free all skbs in the queue; return the sum of their truesizes. */
130unsigned int inet_frag_rbtree_purge(struct rb_root *root);
131
132static inline void inet_frag_put(struct inet_frag_queue *q)
133{
134 if (refcount_dec_and_test(&q->refcnt))
135 inet_frag_destroy(q);
136}
137
138/* Memory Tracking Functions. */
139
140static inline long frag_mem_limit(const struct fqdir *fqdir)
141{
142 return atomic_long_read(&fqdir->mem);
143}
144
145static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
146{
147 atomic_long_sub(val, &fqdir->mem);
148}
149
150static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
151{
152 atomic_long_add(val, &fqdir->mem);
153}
154
155/* RFC 3168 support :
156 * We want to check ECN values of all fragments, do detect invalid combinations.
157 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
158 */
159#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
160#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
161#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
162#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
163
164extern const u8 ip_frag_ecn_table[16];
165
166/* Return values of inet_frag_queue_insert() */
167#define IPFRAG_OK 0
168#define IPFRAG_DUP 1
169#define IPFRAG_OVERLAP 2
170int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
171 int offset, int end);
172void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
173 struct sk_buff *parent);
174void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
175 void *reasm_data, bool try_coalesce);
176struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
177
178#endif