diff options
Diffstat (limited to 'include/net/inet_frag.h')
| -rw-r--r-- | include/net/inet_frag.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h new file mode 100644 index 0000000000..153960663c --- /dev/null +++ b/include/net/inet_frag.h @@ -0,0 +1,194 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_FRAG_H__ +#define __NET_FRAG_H__ + +#include <linux/rhashtable-types.h> +#include <linux/completion.h> +#include <linux/in6.h> +#include <linux/rbtree_types.h> +#include <linux/refcount.h> +#include <net/dropreason-core.h> + +/* Per netns frag queues directory */ +struct fqdir { + /* sysctls */ + long high_thresh; + long low_thresh; + int timeout; + int max_dist; + struct inet_frags *f; + struct net *net; + bool dead; + + struct rhashtable rhashtable ____cacheline_aligned_in_smp; + + /* Keep atomic mem on separate cachelines in structs that include it */ + atomic_long_t mem ____cacheline_aligned_in_smp; + struct work_struct destroy_work; + struct llist_node free_list; +}; + +/** + * enum: fragment queue flags + * + * @INET_FRAG_FIRST_IN: first fragment has arrived + * @INET_FRAG_LAST_IN: final fragment has arrived + * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction + * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable + * @INET_FRAG_DROP: if skbs must be dropped (instead of being consumed) + */ +enum { + INET_FRAG_FIRST_IN = BIT(0), + INET_FRAG_LAST_IN = BIT(1), + INET_FRAG_COMPLETE = BIT(2), + INET_FRAG_HASH_DEAD = BIT(3), + INET_FRAG_DROP = BIT(4), +}; + +struct frag_v4_compare_key { + __be32 saddr; + __be32 daddr; + u32 user; + u32 vif; + __be16 id; + u16 protocol; +}; + +struct frag_v6_compare_key { + struct in6_addr saddr; + struct in6_addr daddr; + u32 user; + __be32 id; + u32 iif; +}; + +/** + * struct inet_frag_queue - fragment queue + * + * @node: rhash node + * @key: keys identifying this frag. + * @timer: queue expiration timer + * @lock: spinlock protecting this frag + * @refcnt: reference count of the queue + * @rb_fragments: received fragments rb-tree root + * @fragments_tail: received fragments tail + * @last_run_head: the head of the last "run". see ip_fragment.c + * @stamp: timestamp of the last received fragment + * @len: total length of the original datagram + * @meat: length of received fragments so far + * @mono_delivery_time: stamp has a mono delivery time (EDT) + * @flags: fragment queue flags + * @max_size: maximum received fragment size + * @fqdir: pointer to struct fqdir + * @rcu: rcu head for freeing deferall + */ +struct inet_frag_queue { + struct rhash_head node; + union { + struct frag_v4_compare_key v4; + struct frag_v6_compare_key v6; + } key; + struct timer_list timer; + spinlock_t lock; + refcount_t refcnt; + struct rb_root rb_fragments; + struct sk_buff *fragments_tail; + struct sk_buff *last_run_head; + ktime_t stamp; + int len; + int meat; + u8 mono_delivery_time; + __u8 flags; + u16 max_size; + struct fqdir *fqdir; + struct rcu_head rcu; +}; + +struct inet_frags { + unsigned int qsize; + + void (*constructor)(struct inet_frag_queue *q, + const void *arg); + void (*destructor)(struct inet_frag_queue *); + void (*frag_expire)(struct timer_list *t); + struct kmem_cache *frags_cachep; + const char *frags_cache_name; + struct rhashtable_params rhash_params; + refcount_t refcnt; + struct completion completion; +}; + +int inet_frags_init(struct inet_frags *); +void inet_frags_fini(struct inet_frags *); + +int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net); + +static inline void fqdir_pre_exit(struct fqdir *fqdir) +{ + /* Prevent creation of new frags. + * Pairs with READ_ONCE() in inet_frag_find(). + */ + WRITE_ONCE(fqdir->high_thresh, 0); + + /* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire() + * and ip6frag_expire_frag_queue(). + */ + WRITE_ONCE(fqdir->dead, true); +} +void fqdir_exit(struct fqdir *fqdir); + +void inet_frag_kill(struct inet_frag_queue *q); +void inet_frag_destroy(struct inet_frag_queue *q); +struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key); + +/* Free all skbs in the queue; return the sum of their truesizes. */ +unsigned int inet_frag_rbtree_purge(struct rb_root *root, + enum skb_drop_reason reason); + +static inline void inet_frag_put(struct inet_frag_queue *q) +{ + if (refcount_dec_and_test(&q->refcnt)) + inet_frag_destroy(q); +} + +/* Memory Tracking Functions. */ + +static inline long frag_mem_limit(const struct fqdir *fqdir) +{ + return atomic_long_read(&fqdir->mem); +} + +static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val) +{ + atomic_long_sub(val, &fqdir->mem); +} + +static inline void add_frag_mem_limit(struct fqdir *fqdir, long val) +{ + atomic_long_add(val, &fqdir->mem); +} + +/* RFC 3168 support : + * We want to check ECN values of all fragments, do detect invalid combinations. + * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value. + */ +#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */ +#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */ +#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */ +#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */ + +extern const u8 ip_frag_ecn_table[16]; + +/* Return values of inet_frag_queue_insert() */ +#define IPFRAG_OK 0 +#define IPFRAG_DUP 1 +#define IPFRAG_OVERLAP 2 +int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, + int offset, int end); +void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, + struct sk_buff *parent); +void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, + void *reasm_data, bool try_coalesce); +struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q); + +#endif |