--- /dev/null
+#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
Code Review / kvmfornfv.git / blobdiff