#ifndef __NET_FRAG_H__
#define __NET_FRAG_H__
#include <linux/percpu_counter.h>
struct netns_frags {
int nqueues;
struct list_head lru_list;
spinlock_t lru_lock;
/* 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;
};
struct inet_frag_queue {
spinlock_t lock;
struct timer_list timer; /* when will this queue expire? */
struct list_head lru_list; /* lru list member */
struct hlist_node list;
atomic_t refcnt;
struct sk_buff *fragments; /* list of received fragments */
struct sk_buff *fragments_tail;
ktime_t stamp;
int len; /* total length of orig datagram */
int meat;
__u8 last_in; /* first/last segment arrived? */
#define INET_FRAG_COMPLETE 4
#define INET_FRAG_FIRST_IN 2
#define INET_FRAG_LAST_IN 1
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];
/* This rwlock is a global lock (seperate per IPv4, IPv6 and
* netfilter). Important to keep this on a seperate cacheline.
* Its primarily a rebuild protection rwlock.
*/
rwlock_t lock ____cacheline_aligned_in_smp;
int secret_interval;
struct timer_list secret_timer;
/* The first call to hashfn is responsible to initialize
* rnd. This is best done with net_get_random_once.
*/
u32 rnd;
int qsize;
unsigned int (*hashfn)(struct inet_frag_queue *);
bool (*match)(struct inet_frag_queue *q, void *arg);
void (*constructor)(struct inet_frag_queue *q,
void *arg);
void (*destructor)(struct inet_frag_queue *);
void (*skb_free)(struct sk_buff *);
void (*frag_expire)(unsigned long data);
};
void 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, int *work);
int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force);
struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
struct inet_frags *f, void *key, unsigned int hash)
__releases(&f->lock);
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, NULL);
}
/* 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);
}
static inline int sum_frag_mem_limit(struct netns_frags *nf)
{
int res;
local_bh_disable();
res = percpu_counter_sum_positive(&nf->mem);
local_bh_enable();
return res;
}
static inline void inet_frag_lru_move(struct inet_frag_queue *q)
{
spin_lock(&q->net->lru_lock);
if (!list_empty(&q->lru_list))
list_move_tail(&q->lru_list, &q->net->lru_list);
spin_unlock(&q->net->lru_lock);
}
static inline void inet_frag_lru_del(struct inet_frag_queue *q)
{
spin_lock(&q->net->lru_lock);
list_del_init(&q->lru_list);
q->net->nqueues--;
spin_unlock(&q->net->lru_lock);
}
static inline void inet_frag_lru_add(struct netns_frags *nf,
struct inet_frag_queue *q)
{
spin_lock(&nf->lru_lock);
list_add_tail(&q->lru_list, &nf->lru_list);
q->net->nqueues++;
spin_unlock(&nf->lru_lock);
}
/* 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
