dst.c File Reference

#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <net/dst.h>

Go to the source code of this file.

Functions
void	dst_run_gc (unsigned long)
int	dst_discard (struct sk_buff *skb)
int	dst_blackhole (struct sk_buff *skb)
void *	dst_alloc (struct dst_ops *ops)
void	__dst_free (struct dst_entry *dst)
void	dst_destroy (struct dst_entry *dst)
int	dst_dev_event (struct notifier_block *this, unsigned long event, void *ptr)
void __init	dst_init (void)
Variables
dst_entry *	dst_garbage_list
spinlock_t	dst_lock = SPIN_LOCK_UNLOCKED
unsigned long	dst_gc_timer_expires
unsigned long	dst_gc_timer_inc = DST_GC_MAX
timer_list	dst_gc_timer
notifier_block	dst_dev_notifier

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Function Documentation

void __dst_free (  struct dst_entry *  dst  )

Definition at line 120 of file dst.c. References dst_entry::dev, dst_blackhole(), dst_discard(), dst_garbage_list, DST_GC_INC, DST_GC_MIN, dst_gc_timer, dst_gc_timer_expires, dst_gc_timer_inc, dst_lock, net_device::flags, dst_entry::input, dst_entry::next, dst_entry::obsolete, and dst_entry::output. Referenced by dst_free(). { spin_lock_bh(&dst_lock); /* The first case (dev==NULL) is required, when protocol module is unloaded. */ if (dst->dev == NULL || !(dst->dev->flags&IFF_UP)) { dst->input = dst_discard; dst->output = dst_blackhole; } dst->obsolete = 2; dst->next = dst_garbage_list; dst_garbage_list = dst; if (dst_gc_timer_inc > DST_GC_INC) { dst_gc_timer_inc = DST_GC_INC; dst_gc_timer_expires = DST_GC_MIN; mod_timer(&dst_gc_timer, jiffies + dst_gc_timer_expires); } spin_unlock_bh(&dst_lock); }

void* dst_alloc (  struct dst_ops *  ops  )

Definition at line 96 of file dst.c. References dst_blackhole(), dst_discard(), dst_ops::entries, dst_ops::entry_size, dst_ops::gc, dst_ops::gc_thresh, and dst_ops::kmem_cachep. Referenced by ip_route_input_mc(), ip_route_input_slow(), ip_route_output_slow(), and ip_rt_redirect(). { struct dst_entry * dst; if (ops->gc && atomic_read(&ops->entries) > ops->gc_thresh) { if (ops->gc()) return NULL; } dst = kmem_cache_alloc(ops->kmem_cachep, SLAB_ATOMIC); if (!dst) return NULL; memset(dst, 0, ops->entry_size); atomic_set(&dst->__refcnt, 0); dst->ops = ops; dst->lastuse = jiffies; dst->input = dst_discard; dst->output = dst_blackhole; #if RT_CACHE_DEBUG >= 2 atomic_inc(&dst_total); #endif atomic_inc(&ops->entries); return dst; }

int dst_blackhole (  struct sk_buff *  skb  )  [static]

Definition at line 90 of file dst.c. References kfree_skb(). Referenced by __dst_free(), dst_alloc(), and dst_dev_event(). { kfree_skb(skb); return 0; }

void dst_destroy (  struct dst_entry *  dst  )

Definition at line 143 of file dst.c. References dst_ops::destroy, dst_entry::dev, dev_put(), dst_ops::entries, dst_entry::hh, dst_ops::kmem_cachep, neigh_release(), dst_entry::neighbour, and dst_entry::ops. Referenced by dst_free(), and dst_run_gc(). { struct neighbour *neigh = dst->neighbour; struct hh_cache *hh = dst->hh; dst->hh = NULL; if (hh && atomic_dec_and_test(&hh->hh_refcnt)) kfree(hh); if (neigh) { dst->neighbour = NULL; neigh_release(neigh); } atomic_dec(&dst->ops->entries); if (dst->ops->destroy) dst->ops->destroy(dst); if (dst->dev) dev_put(dst->dev); #if RT_CACHE_DEBUG >= 2 atomic_dec(&dst_total); #endif kmem_cache_free(dst->ops->kmem_cachep, dst); }

int dst_dev_event (  struct notifier_block *  this, unsigned long  event, void *  ptr )  [static]

Definition at line 169 of file dst.c. References dev_hold, dev_put(), dst_blackhole(), dst_discard(), dst_garbage_list, dst_lock, loopback_dev, NETIF_F_DYNALLOC, and dst_entry::next. { struct net_device *dev = ptr; struct dst_entry *dst; switch (event) { case NETDEV_UNREGISTER: case NETDEV_DOWN: spin_lock_bh(&dst_lock); for (dst = dst_garbage_list; dst; dst = dst->next) { if (dst->dev == dev) { /* Dirty hack. We did it in 2.2 (in __dst_free), we have _very_ good reasons not to repeat this mistake in 2.3, but we have no choice now. _It_ _is_ _explicit_ _deliberate_ _race_ _condition_. */ if (event!=NETDEV_DOWN && !(dev->features & NETIF_F_DYNALLOC) && dst->output == dst_blackhole) { dst->dev = &loopback_dev; dev_put(dev); dev_hold(&loopback_dev); dst->output = dst_discard; if (dst->neighbour && dst->neighbour->dev == dev) { dst->neighbour->dev = &loopback_dev; dev_put(dev); dev_hold(&loopback_dev); } } else { dst->input = dst_discard; dst->output = dst_blackhole; } } } spin_unlock_bh(&dst_lock); break; } return NOTIFY_DONE; }

int dst_discard (  struct sk_buff *  skb  )  [static]

Definition at line 84 of file dst.c. References kfree_skb(). Referenced by __dst_free(), dst_alloc(), and dst_dev_event(). { kfree_skb(skb); return 0; }

void __init dst_init (  void   )

Definition at line 216 of file dst.c. References dst_dev_notifier, and register_netdevice_notifier(). Referenced by net_dev_init(). { register_netdevice_notifier(&dst_dev_notifier); }

void dst_run_gc (  unsigned  long  )  [static]

Definition at line 44 of file dst.c. References dst_destroy(), dst_garbage_list, DST_GC_INC, DST_GC_MAX, dst_gc_timer, dst_gc_timer_expires, dst_gc_timer_inc, dst_lock, and dst_entry::next. { int delayed = 0; struct dst_entry * dst, **dstp; if (!spin_trylock(&dst_lock)) { mod_timer(&dst_gc_timer, jiffies + HZ/10); return; } del_timer(&dst_gc_timer); dstp = &dst_garbage_list; while ((dst = *dstp) != NULL) { if (atomic_read(&dst->__refcnt)) { dstp = &dst->next; delayed++; continue; } *dstp = dst->next; dst_destroy(dst); } if (!dst_garbage_list) { dst_gc_timer_inc = DST_GC_MAX; goto out; } if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX) dst_gc_timer_expires = DST_GC_MAX; dst_gc_timer_inc += DST_GC_INC; dst_gc_timer.expires = jiffies + dst_gc_timer_expires; #if RT_CACHE_DEBUG >= 2 printk("dst_total: %d/%d %ld\n", atomic_read(&dst_total), delayed, dst_gc_timer_expires); #endif add_timer(&dst_gc_timer); out: spin_unlock(&dst_lock); }

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Variable Documentation

struct notifier_block dst_dev_notifier

Initial value: { dst_dev_event, NULL, 0 } Definition at line 210 of file dst.c. Referenced by dst_init().

struct dst_entry* dst_garbage_list [static]

Definition at line 30 of file dst.c. Referenced by __dst_free(), dst_dev_event(), and dst_run_gc().

struct timer_list dst_gc_timer [static]

Initial value: { data: DST_GC_MIN, function: dst_run_gc } Definition at line 40 of file dst.c. Referenced by __dst_free(), and dst_run_gc().

unsigned long dst_gc_timer_expires [static]

Definition at line 36 of file dst.c. Referenced by __dst_free(), and dst_run_gc().

unsigned long dst_gc_timer_inc = DST_GC_MAX [static]

Definition at line 37 of file dst.c. Referenced by __dst_free(), and dst_run_gc().

spinlock_t dst_lock = SPIN_LOCK_UNLOCKED [static]

Definition at line 34 of file dst.c. Referenced by __dst_free(), dst_dev_event(), and dst_run_gc().

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