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 * @rb_fragments: received fragments rb-tree root 60 * @fragments_tail: received fragments tail 61 * @last_run_head: the head of the last "run". see ip_fragment.c 62 * @stamp: timestamp of the last received fragment 63 * @len: total length of the original datagram 64 * @meat: length of received fragments so far 65 * @flags: fragment queue flags 66 * @max_size: maximum received fragment size 67 * @net: namespace that this frag belongs to 68 * @rcu: rcu head for freeing deferall 69 */ 70 struct inet_frag_queue { 71 struct rhash_head node; 72 union { 73 struct frag_v4_compare_key v4; 74 struct frag_v6_compare_key v6; 75 } key; 76 struct timer_list timer; 77 spinlock_t lock; 78 refcount_t refcnt; 79 struct rb_root rb_fragments; 80 struct sk_buff *fragments_tail; 81 struct sk_buff *last_run_head; 82 ktime_t stamp; 83 int len; 84 int meat; 85 __u8 flags; 86 u16 max_size; 87 struct netns_frags *net; 88 struct rcu_head rcu; 89 }; 90 91 struct inet_frags { 92 unsigned int qsize; 93 94 void (*constructor)(struct inet_frag_queue *q, 95 const void *arg); 96 void (*destructor)(struct inet_frag_queue *); 97 void (*frag_expire)(struct timer_list *t); 98 struct kmem_cache *frags_cachep; 99 const char *frags_cache_name; 100 struct rhashtable_params rhash_params; 101 }; 102 103 int inet_frags_init(struct inet_frags *); 104 void inet_frags_fini(struct inet_frags *); 105 106 static inline int inet_frags_init_net(struct netns_frags *nf) 107 { 108 atomic_long_set(&nf->mem, 0); 109 return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params); 110 } 111 void inet_frags_exit_net(struct netns_frags *nf); 112 113 void inet_frag_kill(struct inet_frag_queue *q); 114 void inet_frag_destroy(struct inet_frag_queue *q); 115 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key); 116 117 /* Free all skbs in the queue; return the sum of their truesizes. */ 118 unsigned int inet_frag_rbtree_purge(struct rb_root *root); 119 120 static inline void inet_frag_put(struct inet_frag_queue *q) 121 { 122 if (refcount_dec_and_test(&q->refcnt)) 123 inet_frag_destroy(q); 124 } 125 126 /* Memory Tracking Functions. */ 127 128 static inline long frag_mem_limit(const struct netns_frags *nf) 129 { 130 return atomic_long_read(&nf->mem); 131 } 132 133 static inline void sub_frag_mem_limit(struct netns_frags *nf, long val) 134 { 135 atomic_long_sub(val, &nf->mem); 136 } 137 138 static inline void add_frag_mem_limit(struct netns_frags *nf, long val) 139 { 140 atomic_long_add(val, &nf->mem); 141 } 142 143 /* RFC 3168 support : 144 * We want to check ECN values of all fragments, do detect invalid combinations. 145 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value. 146 */ 147 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */ 148 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */ 149 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */ 150 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */ 151 152 extern const u8 ip_frag_ecn_table[16]; 153 154 /* Return values of inet_frag_queue_insert() */ 155 #define IPFRAG_OK 0 156 #define IPFRAG_DUP 1 157 #define IPFRAG_OVERLAP 2 158 int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, 159 int offset, int end); 160 void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, 161 struct sk_buff *parent); 162 void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, 163 void *reasm_data); 164 struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q); 165 166 #endif 167