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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /net/ipv4/inet_fragment.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'net/ipv4/inet_fragment.c')
-rw-r--r-- | net/ipv4/inet_fragment.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c new file mode 100644 index 00000000..5ff2a51b --- /dev/null +++ b/net/ipv4/inet_fragment.c @@ -0,0 +1,286 @@ +/* + * inet fragments management + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Pavel Emelyanov <xemul@openvz.org> + * Started as consolidation of ipv4/ip_fragment.c, + * ipv6/reassembly. and ipv6 nf conntrack reassembly + */ + +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/module.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/random.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> + +#include <net/inet_frag.h> + +static void inet_frag_secret_rebuild(unsigned long dummy) +{ + struct inet_frags *f = (struct inet_frags *)dummy; + unsigned long now = jiffies; + int i; + + write_lock(&f->lock); + get_random_bytes(&f->rnd, sizeof(u32)); + for (i = 0; i < INETFRAGS_HASHSZ; i++) { + struct inet_frag_queue *q; + struct hlist_node *p, *n; + + hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) { + unsigned int hval = f->hashfn(q); + + if (hval != i) { + hlist_del(&q->list); + + /* Relink to new hash chain. */ + hlist_add_head(&q->list, &f->hash[hval]); + } + } + } + write_unlock(&f->lock); + + mod_timer(&f->secret_timer, now + f->secret_interval); +} + +void inet_frags_init(struct inet_frags *f) +{ + int i; + + for (i = 0; i < INETFRAGS_HASHSZ; i++) + INIT_HLIST_HEAD(&f->hash[i]); + + rwlock_init(&f->lock); + + f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^ + (jiffies ^ (jiffies >> 6))); + + setup_timer(&f->secret_timer, inet_frag_secret_rebuild, + (unsigned long)f); + f->secret_timer.expires = jiffies + f->secret_interval; + add_timer(&f->secret_timer); +} +EXPORT_SYMBOL(inet_frags_init); + +void inet_frags_init_net(struct netns_frags *nf) +{ + nf->nqueues = 0; + atomic_set(&nf->mem, 0); + INIT_LIST_HEAD(&nf->lru_list); +} +EXPORT_SYMBOL(inet_frags_init_net); + +void inet_frags_fini(struct inet_frags *f) +{ + del_timer(&f->secret_timer); +} +EXPORT_SYMBOL(inet_frags_fini); + +void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f) +{ + nf->low_thresh = 0; + + local_bh_disable(); + inet_frag_evictor(nf, f); + local_bh_enable(); +} +EXPORT_SYMBOL(inet_frags_exit_net); + +static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f) +{ + write_lock(&f->lock); + hlist_del(&fq->list); + list_del(&fq->lru_list); + fq->net->nqueues--; + write_unlock(&f->lock); +} + +void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f) +{ + if (del_timer(&fq->timer)) + atomic_dec(&fq->refcnt); + + if (!(fq->last_in & INET_FRAG_COMPLETE)) { + fq_unlink(fq, f); + atomic_dec(&fq->refcnt); + fq->last_in |= INET_FRAG_COMPLETE; + } +} +EXPORT_SYMBOL(inet_frag_kill); + +static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f, + struct sk_buff *skb, int *work) +{ + if (work) + *work -= skb->truesize; + + atomic_sub(skb->truesize, &nf->mem); + if (f->skb_free) + f->skb_free(skb); + kfree_skb(skb); +} + +void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f, + int *work) +{ + struct sk_buff *fp; + struct netns_frags *nf; + + WARN_ON(!(q->last_in & INET_FRAG_COMPLETE)); + WARN_ON(del_timer(&q->timer) != 0); + + /* Release all fragment data. */ + fp = q->fragments; + nf = q->net; + while (fp) { + struct sk_buff *xp = fp->next; + + frag_kfree_skb(nf, f, fp, work); + fp = xp; + } + + if (work) + *work -= f->qsize; + atomic_sub(f->qsize, &nf->mem); + + if (f->destructor) + f->destructor(q); + kfree(q); + +} +EXPORT_SYMBOL(inet_frag_destroy); + +int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f) +{ + struct inet_frag_queue *q; + int work, evicted = 0; + + work = atomic_read(&nf->mem) - nf->low_thresh; + while (work > 0) { + read_lock(&f->lock); + if (list_empty(&nf->lru_list)) { + read_unlock(&f->lock); + break; + } + + q = list_first_entry(&nf->lru_list, + struct inet_frag_queue, lru_list); + atomic_inc(&q->refcnt); + read_unlock(&f->lock); + + spin_lock(&q->lock); + if (!(q->last_in & INET_FRAG_COMPLETE)) + inet_frag_kill(q, f); + spin_unlock(&q->lock); + + if (atomic_dec_and_test(&q->refcnt)) + inet_frag_destroy(q, f, &work); + evicted++; + } + + return evicted; +} +EXPORT_SYMBOL(inet_frag_evictor); + +static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf, + struct inet_frag_queue *qp_in, struct inet_frags *f, + void *arg) +{ + struct inet_frag_queue *qp; +#ifdef CONFIG_SMP + struct hlist_node *n; +#endif + unsigned int hash; + + write_lock(&f->lock); + /* + * While we stayed w/o the lock other CPU could update + * the rnd seed, so we need to re-calculate the hash + * chain. Fortunatelly the qp_in can be used to get one. + */ + hash = f->hashfn(qp_in); +#ifdef CONFIG_SMP + /* With SMP race we have to recheck hash table, because + * such entry could be created on other cpu, while we + * promoted read lock to write lock. + */ + hlist_for_each_entry(qp, n, &f->hash[hash], list) { + if (qp->net == nf && f->match(qp, arg)) { + atomic_inc(&qp->refcnt); + write_unlock(&f->lock); + qp_in->last_in |= INET_FRAG_COMPLETE; + inet_frag_put(qp_in, f); + return qp; + } + } +#endif + qp = qp_in; + if (!mod_timer(&qp->timer, jiffies + nf->timeout)) + atomic_inc(&qp->refcnt); + + atomic_inc(&qp->refcnt); + hlist_add_head(&qp->list, &f->hash[hash]); + list_add_tail(&qp->lru_list, &nf->lru_list); + nf->nqueues++; + write_unlock(&f->lock); + return qp; +} + +static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf, + struct inet_frags *f, void *arg) +{ + struct inet_frag_queue *q; + + q = kzalloc(f->qsize, GFP_ATOMIC); + if (q == NULL) + return NULL; + + f->constructor(q, arg); + atomic_add(f->qsize, &nf->mem); + setup_timer(&q->timer, f->frag_expire, (unsigned long)q); + spin_lock_init(&q->lock); + atomic_set(&q->refcnt, 1); + q->net = nf; + + return q; +} + +static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf, + struct inet_frags *f, void *arg) +{ + struct inet_frag_queue *q; + + q = inet_frag_alloc(nf, f, arg); + if (q == NULL) + return NULL; + + return inet_frag_intern(nf, q, f, arg); +} + +struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, + struct inet_frags *f, void *key, unsigned int hash) + __releases(&f->lock) +{ + struct inet_frag_queue *q; + struct hlist_node *n; + + hlist_for_each_entry(q, n, &f->hash[hash], list) { + if (q->net == nf && f->match(q, key)) { + atomic_inc(&q->refcnt); + read_unlock(&f->lock); + return q; + } + } + read_unlock(&f->lock); + + return inet_frag_create(nf, f, key); +} +EXPORT_SYMBOL(inet_frag_find); |