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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __NET_FRAG_H__ #define __NET_FRAG_H__ #include <linux/rhashtable-types.h> #include <linux/completion.h> #include <linux/in6.h> #include <linux/rbtree_types.h> #include <linux/refcount.h> /* Per netns frag queues directory */ struct fqdir { /* sysctls */ long high_thresh; long low_thresh; int timeout; int max_dist; struct inet_frags *f; struct net *net; bool dead; struct rhashtable rhashtable ____cacheline_aligned_in_smp; /* Keep atomic mem on separate cachelines in structs that include it */ atomic_long_t mem ____cacheline_aligned_in_smp; struct work_struct destroy_work; struct llist_node free_list; }; /** * fragment queue flags * * @INET_FRAG_FIRST_IN: first fragment has arrived * @INET_FRAG_LAST_IN: final fragment has arrived * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable */ enum { INET_FRAG_FIRST_IN = BIT(0), INET_FRAG_LAST_IN = BIT(1), INET_FRAG_COMPLETE = BIT(2), INET_FRAG_HASH_DEAD = BIT(3), }; struct frag_v4_compare_key { __be32 saddr; __be32 daddr; u32 user; u32 vif; __be16 id; u16 protocol; }; struct frag_v6_compare_key { struct in6_addr saddr; struct in6_addr daddr; u32 user; __be32 id; u32 iif; }; /** * struct inet_frag_queue - fragment queue * * @node: rhash node * @key: keys identifying this frag. * @timer: queue expiration timer * @lock: spinlock protecting this frag * @refcnt: reference count of the queue * @rb_fragments: received fragments rb-tree root * @fragments_tail: received fragments tail * @last_run_head: the head of the last "run". see ip_fragment.c * @stamp: timestamp of the last received fragment * @len: total length of the original datagram * @meat: length of received fragments so far * @mono_delivery_time: stamp has a mono delivery time (EDT) * @flags: fragment queue flags * @max_size: maximum received fragment size * @fqdir: pointer to struct fqdir * @rcu: rcu head for freeing deferall */ struct inet_frag_queue { struct rhash_head node; union { struct frag_v4_compare_key v4; struct frag_v6_compare_key v6; } key; struct timer_list timer; spinlock_t lock; refcount_t refcnt; struct rb_root rb_fragments; struct sk_buff *fragments_tail; struct sk_buff *last_run_head; ktime_t stamp; int len; int meat; u8 mono_delivery_time; __u8 flags; u16 max_size; struct fqdir *fqdir; struct rcu_head rcu; }; struct inet_frags { unsigned int qsize; void (*constructor)(struct inet_frag_queue *q, const void *arg); void (*destructor)(struct inet_frag_queue *); void (*frag_expire)(struct timer_list *t); struct kmem_cache *frags_cachep; const char *frags_cache_name; struct rhashtable_params rhash_params; refcount_t refcnt; struct completion completion; }; int inet_frags_init(struct inet_frags *); void inet_frags_fini(struct inet_frags *); int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net); static inline void fqdir_pre_exit(struct fqdir *fqdir) { /* Prevent creation of new frags. * Pairs with READ_ONCE() in inet_frag_find(). */ WRITE_ONCE(fqdir->high_thresh, 0); /* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire() * and ip6frag_expire_frag_queue(). */ WRITE_ONCE(fqdir->dead, true); } void fqdir_exit(struct fqdir *fqdir); void inet_frag_kill(struct inet_frag_queue *q); void inet_frag_destroy(struct inet_frag_queue *q); struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key); /* Free all skbs in the queue; return the sum of their truesizes. */ unsigned int inet_frag_rbtree_purge(struct rb_root *root); static inline void inet_frag_put(struct inet_frag_queue *q) { if (refcount_dec_and_test(&q->refcnt)) inet_frag_destroy(q); } /* Memory Tracking Functions. */ static inline long frag_mem_limit(const struct fqdir *fqdir) { return atomic_long_read(&fqdir->mem); } static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val) { atomic_long_sub(val, &fqdir->mem); } static inline void add_frag_mem_limit(struct fqdir *fqdir, long val) { atomic_long_add(val, &fqdir->mem); } /* RFC 3168 support : * We want to check ECN values of all fragments, do detect invalid combinations. * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value. */ #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */ #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */ #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */ #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */ extern const u8 ip_frag_ecn_table[16]; /* Return values of inet_frag_queue_insert() */ #define IPFRAG_OK 0 #define IPFRAG_DUP 1 #define IPFRAG_OVERLAP 2 int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, int offset, int end); void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, struct sk_buff *parent); void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, void *reasm_data, bool try_coalesce); struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q); #endif |