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
7 struct 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 */
28 enum {
29 INET_FRAG_FIRST_IN = BIT(0),
30 INET_FRAG_LAST_IN = BIT(1),
31 INET_FRAG_COMPLETE = BIT(2),
32 };
33
34 struct frag_v4_compare_key {
35 __be32 saddr;
36 __be32 daddr;
37 u32 user;
38 u32 vif;
39 __be16 id;
40 u16 protocol;
41 };
42
43 struct 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 * @rb_fragments: received fragments rb-tree root
61 * @fragments_tail: received fragments tail
62 * @last_run_head: the head of the last "run". see ip_fragment.c
63 * @stamp: timestamp of the last received fragment
64 * @len: total length of the original datagram
65 * @meat: length of received fragments so far
66 * @flags: fragment queue flags
67 * @max_size: maximum received fragment size
68 * @net: namespace that this frag belongs to
69 * @rcu: rcu head for freeing deferall
70 */
71 struct inet_frag_queue {
72 struct rhash_head node;
73 union {
74 struct frag_v4_compare_key v4;
75 struct frag_v6_compare_key v6;
76 } key;
77 struct timer_list timer;
78 spinlock_t lock;
79 refcount_t refcnt;
80 struct sk_buff *fragments; /* used in 6lopwpan IPv6. */
81 struct rb_root rb_fragments; /* Used in IPv4/IPv6. */
82 struct sk_buff *fragments_tail;
83 struct sk_buff *last_run_head;
84 ktime_t stamp;
85 int len;
86 int meat;
87 __u8 flags;
88 u16 max_size;
89 struct netns_frags *net;
90 struct rcu_head rcu;
91 };
92
93 struct inet_frags {
94 unsigned int qsize;
95
96 void (*constructor)(struct inet_frag_queue *q,
97 const void *arg);
98 void (*destructor)(struct inet_frag_queue *);
99 void (*frag_expire)(struct timer_list *t);
100 struct kmem_cache *frags_cachep;
101 const char *frags_cache_name;
102 struct rhashtable_params rhash_params;
103 };
104
105 int inet_frags_init(struct inet_frags *);
106 void inet_frags_fini(struct inet_frags *);
107
inet_frags_init_net(struct netns_frags * nf)108 static inline int inet_frags_init_net(struct netns_frags *nf)
109 {
110 atomic_long_set(&nf->mem, 0);
111 return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params);
112 }
113 void inet_frags_exit_net(struct netns_frags *nf);
114
115 void inet_frag_kill(struct inet_frag_queue *q);
116 void inet_frag_destroy(struct inet_frag_queue *q);
117 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key);
118
119 /* Free all skbs in the queue; return the sum of their truesizes. */
120 unsigned int inet_frag_rbtree_purge(struct rb_root *root);
121
inet_frag_put(struct inet_frag_queue * q)122 static inline void inet_frag_put(struct inet_frag_queue *q)
123 {
124 if (refcount_dec_and_test(&q->refcnt))
125 inet_frag_destroy(q);
126 }
127
128 /* Memory Tracking Functions. */
129
frag_mem_limit(const struct netns_frags * nf)130 static inline long frag_mem_limit(const struct netns_frags *nf)
131 {
132 return atomic_long_read(&nf->mem);
133 }
134
sub_frag_mem_limit(struct netns_frags * nf,long val)135 static inline void sub_frag_mem_limit(struct netns_frags *nf, long val)
136 {
137 atomic_long_sub(val, &nf->mem);
138 }
139
add_frag_mem_limit(struct netns_frags * nf,long val)140 static inline void add_frag_mem_limit(struct netns_frags *nf, long val)
141 {
142 atomic_long_add(val, &nf->mem);
143 }
144
145 /* RFC 3168 support :
146 * We want to check ECN values of all fragments, do detect invalid combinations.
147 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
148 */
149 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
150 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
151 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
152 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
153
154 extern const u8 ip_frag_ecn_table[16];
155
156 /* Return values of inet_frag_queue_insert() */
157 #define IPFRAG_OK 0
158 #define IPFRAG_DUP 1
159 #define IPFRAG_OVERLAP 2
160 int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
161 int offset, int end);
162 void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
163 struct sk_buff *parent);
164 void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
165 void *reasm_data);
166 struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
167
168 #endif
169