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 */ |
13 | struct 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 | */ |
40 | enum { |
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 | |
48 | struct frag_v4_compare_key { |
49 | __be32 saddr; |
50 | __be32 daddr; |
51 | u32 user; |
52 | u32 vif; |
53 | __be16 id; |
54 | u16 protocol; |
55 | }; |
56 | |
57 | struct 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 | */ |
85 | struct 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 | |
107 | struct 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 | |
121 | int inet_frags_init(struct inet_frags *); |
122 | void inet_frags_fini(struct inet_frags *); |
123 | |
124 | int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net); |
125 | |
126 | static 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 | } |
138 | void fqdir_exit(struct fqdir *fqdir); |
139 | |
140 | void inet_frag_kill(struct inet_frag_queue *q); |
141 | void inet_frag_destroy(struct inet_frag_queue *q); |
142 | struct 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. */ |
145 | unsigned int inet_frag_rbtree_purge(struct rb_root *root, |
146 | enum skb_drop_reason reason); |
147 | |
148 | static inline void inet_frag_put(struct inet_frag_queue *q) |
149 | { |
150 | if (refcount_dec_and_test(r: &q->refcnt)) |
151 | inet_frag_destroy(q); |
152 | } |
153 | |
154 | /* Memory Tracking Functions. */ |
155 | |
156 | static inline long frag_mem_limit(const struct fqdir *fqdir) |
157 | { |
158 | return atomic_long_read(v: &fqdir->mem); |
159 | } |
160 | |
161 | static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val) |
162 | { |
163 | atomic_long_sub(i: val, v: &fqdir->mem); |
164 | } |
165 | |
166 | static inline void add_frag_mem_limit(struct fqdir *fqdir, long val) |
167 | { |
168 | atomic_long_add(i: val, v: &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 | |
180 | extern 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 |
186 | int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, |
187 | int offset, int end); |
188 | void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, |
189 | struct sk_buff *parent); |
190 | void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, |
191 | void *reasm_data, bool try_coalesce); |
192 | struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q); |
193 | |
194 | #endif |
195 | |