1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_FRAG_H__ 3 #define __NET_FRAG_H__ 4 5 #include <linux/rhashtable.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 * @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 */ 69 struct 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 89 struct 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 }; 100 101 int inet_frags_init(struct inet_frags *); 102 void inet_frags_fini(struct inet_frags *); 103 104 static 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 } 109 void inet_frags_exit_net(struct netns_frags *nf); 110 111 void inet_frag_kill(struct inet_frag_queue *q); 112 void inet_frag_destroy(struct inet_frag_queue *q); 113 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key); 114 115 static 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. */ 122 123 static inline long frag_mem_limit(const struct netns_frags *nf) 124 { 125 return atomic_long_read(&nf->mem); 126 } 127 128 static inline void sub_frag_mem_limit(struct netns_frags *nf, long val) 129 { 130 atomic_long_sub(val, &nf->mem); 131 } 132 133 static 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 */ 146 147 extern const u8 ip_frag_ecn_table[16]; 148 149 #endif 150