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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.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 * @fragments: received fragments head
60 * @fragments_tail: received fragments tail
61 * @stamp: timestamp of the last received fragment
62 * @len: total length of the original datagram
63 * @meat: length of received fragments so far
64 * @flags: fragment queue flags
65 * @max_size: maximum received fragment size
66 * @net: namespace that this frag belongs to
67 * @rcu: rcu head for freeing deferall
68 */
69struct inet_frag_queue {
70 struct rhash_head node;
71 union {
72 struct frag_v4_compare_key v4;
73 struct frag_v6_compare_key v6;
74 } key;
75 struct timer_list timer;
76 spinlock_t lock;
77 refcount_t refcnt;
78 struct sk_buff *fragments;
79 struct sk_buff *fragments_tail;
80 ktime_t stamp;
81 int len;
82 int meat;
83 __u8 flags;
84 u16 max_size;
85 struct netns_frags *net;
86 struct rcu_head rcu;
87};
88
89struct inet_frags {
90 unsigned int qsize;
91
92 void (*constructor)(struct inet_frag_queue *q,
93 const void *arg);
94 void (*destructor)(struct inet_frag_queue *);
95 void (*frag_expire)(struct timer_list *t);
96 struct kmem_cache *frags_cachep;
97 const char *frags_cache_name;
98 struct rhashtable_params rhash_params;
99};
100
101int inet_frags_init(struct inet_frags *);
102void inet_frags_fini(struct inet_frags *);
103
104static inline int inet_frags_init_net(struct netns_frags *nf)
105{
106 atomic_long_set(&nf->mem, 0);
107 return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params);
108}
109void inet_frags_exit_net(struct netns_frags *nf);
110
111void inet_frag_kill(struct inet_frag_queue *q);
112void inet_frag_destroy(struct inet_frag_queue *q);
113struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key);
114
115static inline void inet_frag_put(struct inet_frag_queue *q)
116{
117 if (refcount_dec_and_test(&q->refcnt))
118 inet_frag_destroy(q);
119}
120
121/* Memory Tracking Functions. */
122
123static inline long frag_mem_limit(const struct netns_frags *nf)
124{
125 return atomic_long_read(&nf->mem);
126}
127
128static inline void sub_frag_mem_limit(struct netns_frags *nf, long val)
129{
130 atomic_long_sub(val, &nf->mem);
131}
132
133static inline void add_frag_mem_limit(struct netns_frags *nf, long val)
134{
135 atomic_long_add(val, &nf->mem);
136}
137
138/* RFC 3168 support :
139 * We want to check ECN values of all fragments, do detect invalid combinations.
140 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
141 */
142#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
143#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
144#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
145#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
146
147extern const u8 ip_frag_ecn_table[16];
148
149#endif