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