diff options
Diffstat (limited to 'kernel/include/net/inet_frag.h')
| -rw-r--r-- | kernel/include/net/inet_frag.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/kernel/include/net/inet_frag.h b/kernel/include/net/inet_frag.h new file mode 100644 index 000000000..8d1765577 --- /dev/null +++ b/kernel/include/net/inet_frag.h @@ -0,0 +1,179 @@ +#ifndef __NET_FRAG_H__ +#define __NET_FRAG_H__ + +#include <linux/percpu_counter.h> + +struct netns_frags { + /* The percpu_counter "mem" need to be cacheline aligned. + * mem.count must not share cacheline with other writers + */ + struct percpu_counter mem ____cacheline_aligned_in_smp; + + /* sysctls */ + int timeout; + int high_thresh; + int low_thresh; +}; + +/** + * 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_EVICTED: frag queue is being evicted + */ +enum { + INET_FRAG_FIRST_IN = BIT(0), + INET_FRAG_LAST_IN = BIT(1), + INET_FRAG_COMPLETE = BIT(2), + INET_FRAG_EVICTED = BIT(3) +}; + +/** + * struct inet_frag_queue - fragment queue + * + * @lock: spinlock protecting the queue + * @timer: queue expiration timer + * @list: hash bucket list + * @refcnt: reference count of the queue + * @fragments: received fragments head + * @fragments_tail: received fragments tail + * @stamp: timestamp of the last received fragment + * @len: total length of the original datagram + * @meat: length of received fragments so far + * @flags: fragment queue flags + * @max_size: (ipv4 only) maximum received fragment size with IP_DF set + * @net: namespace that this frag belongs to + */ +struct inet_frag_queue { + spinlock_t lock; + struct timer_list timer; + struct hlist_node list; + atomic_t refcnt; + struct sk_buff *fragments; + struct sk_buff *fragments_tail; + ktime_t stamp; + int len; + int meat; + __u8 flags; + u16 max_size; + struct netns_frags *net; +}; + +#define INETFRAGS_HASHSZ 1024 + +/* averaged: + * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ / + * rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or + * struct frag_queue)) + */ +#define INETFRAGS_MAXDEPTH 128 + +struct inet_frag_bucket { + struct hlist_head chain; + spinlock_t chain_lock; +}; + +struct inet_frags { + struct inet_frag_bucket hash[INETFRAGS_HASHSZ]; + + struct work_struct frags_work; + unsigned int next_bucket; + unsigned long last_rebuild_jiffies; + bool rebuild; + + /* The first call to hashfn is responsible to initialize + * rnd. This is best done with net_get_random_once. + * + * rnd_seqlock is used to let hash insertion detect + * when it needs to re-lookup the hash chain to use. + */ + u32 rnd; + seqlock_t rnd_seqlock; + int qsize; + + unsigned int (*hashfn)(const struct inet_frag_queue *); + bool (*match)(const struct inet_frag_queue *q, + const void *arg); + void (*constructor)(struct inet_frag_queue *q, + const void *arg); + void (*destructor)(struct inet_frag_queue *); + void (*skb_free)(struct sk_buff *); + void (*frag_expire)(unsigned long data); + struct kmem_cache *frags_cachep; + const char *frags_cache_name; +}; + +int inet_frags_init(struct inet_frags *); +void inet_frags_fini(struct inet_frags *); + +void inet_frags_init_net(struct netns_frags *nf); +void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f); + +void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f); +void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f); +struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, + struct inet_frags *f, void *key, unsigned int hash); + +void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q, + const char *prefix); + +static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f) +{ + if (atomic_dec_and_test(&q->refcnt)) + inet_frag_destroy(q, f); +} + +/* Memory Tracking Functions. */ + +/* The default percpu_counter batch size is not big enough to scale to + * fragmentation mem acct sizes. + * The mem size of a 64K fragment is approx: + * (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes + */ +static unsigned int frag_percpu_counter_batch = 130000; + +static inline int frag_mem_limit(struct netns_frags *nf) +{ + return percpu_counter_read(&nf->mem); +} + +static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i) +{ + __percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch); +} + +static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i) +{ + __percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch); +} + +static inline void init_frag_mem_limit(struct netns_frags *nf) +{ + percpu_counter_init(&nf->mem, 0, GFP_KERNEL); +} + +static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf) +{ + unsigned int res; + + local_bh_disable(); + res = percpu_counter_sum_positive(&nf->mem); + local_bh_enable(); + + return res; +} + +/* 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]; + +#endif |