166 lines
4.4 KiB
C
166 lines
4.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __NET_FRAG_H__
|
|
#define __NET_FRAG_H__
|
|
|
|
struct netns_frags {
|
|
/* Keep atomic mem on separate cachelines in structs that include it */
|
|
atomic_t mem ____cacheline_aligned_in_smp;
|
|
/* sysctls */
|
|
int timeout;
|
|
int high_thresh;
|
|
int low_thresh;
|
|
int max_dist;
|
|
};
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
enum {
|
|
INET_FRAG_FIRST_IN = BIT(0),
|
|
INET_FRAG_LAST_IN = BIT(1),
|
|
INET_FRAG_COMPLETE = BIT(2),
|
|
};
|
|
|
|
/**
|
|
* 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: maximum received fragment size
|
|
* @net: namespace that this frag belongs to
|
|
* @list_evictor: list of queues to forcefully evict (e.g. due to low memory)
|
|
*/
|
|
struct inet_frag_queue {
|
|
spinlock_t lock;
|
|
struct timer_list timer;
|
|
struct hlist_node list;
|
|
refcount_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;
|
|
struct hlist_node list_evictor;
|
|
};
|
|
|
|
#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;
|
|
unsigned 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 (*frag_expire)(struct timer_list *t);
|
|
struct kmem_cache *frags_cachep;
|
|
const char *frags_cache_name;
|
|
};
|
|
|
|
int inet_frags_init(struct inet_frags *);
|
|
void inet_frags_fini(struct inet_frags *);
|
|
|
|
static inline void inet_frags_init_net(struct netns_frags *nf)
|
|
{
|
|
atomic_set(&nf->mem, 0);
|
|
}
|
|
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 (refcount_dec_and_test(&q->refcnt))
|
|
inet_frag_destroy(q, f);
|
|
}
|
|
|
|
static inline bool inet_frag_evicting(struct inet_frag_queue *q)
|
|
{
|
|
return !hlist_unhashed(&q->list_evictor);
|
|
}
|
|
|
|
/* Memory Tracking Functions. */
|
|
|
|
static inline int frag_mem_limit(struct netns_frags *nf)
|
|
{
|
|
return atomic_read(&nf->mem);
|
|
}
|
|
|
|
static inline void sub_frag_mem_limit(struct netns_frags *nf, int i)
|
|
{
|
|
atomic_sub(i, &nf->mem);
|
|
}
|
|
|
|
static inline void add_frag_mem_limit(struct netns_frags *nf, int i)
|
|
{
|
|
atomic_add(i, &nf->mem);
|
|
}
|
|
|
|
static inline int sum_frag_mem_limit(struct netns_frags *nf)
|
|
{
|
|
return atomic_read(&nf->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];
|
|
|
|
#endif
|