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