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 11 /* Per netns frag queues directory */ 12 struct fqdir { 13 /* sysctls */ 14 long high_thresh; 15 long low_thresh; 16 int timeout; 17 int max_dist; 18 struct inet_frags *f; 19 struct net *net; 20 bool dead; 21 22 struct rhashtable rhashtable ____cacheline_aligned_in_smp; 23 24 /* Keep atomic mem on separate cachelines in structs that include it */ 25 atomic_long_t mem ____cacheline_aligned_in_smp; 26 struct work_struct destroy_work; 27 struct llist_node free_list; 28 }; 29 30 /** 31 * fragment queue flags 32 * 33 * @INET_FRAG_FIRST_IN: first fragment has arrived 34 * @INET_FRAG_LAST_IN: final fragment has arrived 35 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction 36 * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable 37 */ 38 enum { 39 INET_FRAG_FIRST_IN = BIT(0), 40 INET_FRAG_LAST_IN = BIT(1), 41 INET_FRAG_COMPLETE = BIT(2), 42 INET_FRAG_HASH_DEAD = BIT(3), 43 }; 44 45 struct frag_v4_compare_key { 46 __be32 saddr; 47 __be32 daddr; 48 u32 user; 49 u32 vif; 50 __be16 id; 51 u16 protocol; 52 }; 53 54 struct frag_v6_compare_key { 55 struct in6_addr saddr; 56 struct in6_addr daddr; 57 u32 user; 58 __be32 id; 59 u32 iif; 60 }; 61 62 /** 63 * struct inet_frag_queue - fragment queue 64 * 65 * @node: rhash node 66 * @key: keys identifying this frag. 67 * @timer: queue expiration timer 68 * @lock: spinlock protecting this frag 69 * @refcnt: reference count of the queue 70 * @rb_fragments: received fragments rb-tree root 71 * @fragments_tail: received fragments tail 72 * @last_run_head: the head of the last "run". see ip_fragment.c 73 * @stamp: timestamp of the last received fragment 74 * @len: total length of the original datagram 75 * @meat: length of received fragments so far 76 * @mono_delivery_time: stamp has a mono delivery time (EDT) 77 * @flags: fragment queue flags 78 * @max_size: maximum received fragment size 79 * @fqdir: pointer to struct fqdir 80 * @rcu: rcu head for freeing deferall 81 */ 82 struct inet_frag_queue { 83 struct rhash_head node; 84 union { 85 struct frag_v4_compare_key v4; 86 struct frag_v6_compare_key v6; 87 } key; 88 struct timer_list timer; 89 spinlock_t lock; 90 refcount_t refcnt; 91 struct rb_root rb_fragments; 92 struct sk_buff *fragments_tail; 93 struct sk_buff *last_run_head; 94 ktime_t stamp; 95 int len; 96 int meat; 97 u8 mono_delivery_time; 98 __u8 flags; 99 u16 max_size; 100 struct fqdir *fqdir; 101 struct rcu_head rcu; 102 }; 103 104 struct inet_frags { 105 unsigned int qsize; 106 107 void (*constructor)(struct inet_frag_queue *q, 108 const void *arg); 109 void (*destructor)(struct inet_frag_queue *); 110 void (*frag_expire)(struct timer_list *t); 111 struct kmem_cache *frags_cachep; 112 const char *frags_cache_name; 113 struct rhashtable_params rhash_params; 114 refcount_t refcnt; 115 struct completion completion; 116 }; 117 118 int inet_frags_init(struct inet_frags *); 119 void inet_frags_fini(struct inet_frags *); 120 121 int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net); 122 123 static inline void fqdir_pre_exit(struct fqdir *fqdir) 124 { 125 /* Prevent creation of new frags. 126 * Pairs with READ_ONCE() in inet_frag_find(). 127 */ 128 WRITE_ONCE(fqdir->high_thresh, 0); 129 130 /* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire() 131 * and ip6frag_expire_frag_queue(). 132 */ 133 WRITE_ONCE(fqdir->dead, true); 134 } 135 void fqdir_exit(struct fqdir *fqdir); 136 137 void inet_frag_kill(struct inet_frag_queue *q); 138 void inet_frag_destroy(struct inet_frag_queue *q); 139 struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key); 140 141 /* Free all skbs in the queue; return the sum of their truesizes. */ 142 unsigned int inet_frag_rbtree_purge(struct rb_root *root); 143 144 static inline void inet_frag_put(struct inet_frag_queue *q) 145 { 146 if (refcount_dec_and_test(&q->refcnt)) 147 inet_frag_destroy(q); 148 } 149 150 /* Memory Tracking Functions. */ 151 152 static inline long frag_mem_limit(const struct fqdir *fqdir) 153 { 154 return atomic_long_read(&fqdir->mem); 155 } 156 157 static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val) 158 { 159 atomic_long_sub(val, &fqdir->mem); 160 } 161 162 static inline void add_frag_mem_limit(struct fqdir *fqdir, long val) 163 { 164 atomic_long_add(val, &fqdir->mem); 165 } 166 167 /* RFC 3168 support : 168 * We want to check ECN values of all fragments, do detect invalid combinations. 169 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value. 170 */ 171 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */ 172 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */ 173 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */ 174 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */ 175 176 extern const u8 ip_frag_ecn_table[16]; 177 178 /* Return values of inet_frag_queue_insert() */ 179 #define IPFRAG_OK 0 180 #define IPFRAG_DUP 1 181 #define IPFRAG_OVERLAP 2 182 int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, 183 int offset, int end); 184 void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, 185 struct sk_buff *parent); 186 void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, 187 void *reasm_data, bool try_coalesce); 188 struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q); 189 190 #endif 191