diff options
Diffstat (limited to 'pfinet/linux-src/net/core/neighbour.c')
| -rw-r--r-- | pfinet/linux-src/net/core/neighbour.c | 1394 |
1 files changed, 1394 insertions, 0 deletions
diff --git a/pfinet/linux-src/net/core/neighbour.c b/pfinet/linux-src/net/core/neighbour.c new file mode 100644 index 00000000..6afbfdcc --- /dev/null +++ b/pfinet/linux-src/net/core/neighbour.c @@ -0,0 +1,1394 @@ +/* + * Generic address resolution entity + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> + * + * 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. + * + * Fixes: + * Vitaly E. Lavrov releasing NULL neighbor in neigh_add. + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/socket.h> +#include <linux/sched.h> +#include <linux/netdevice.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#endif +#include <net/neighbour.h> +#include <net/dst.h> +#include <net/sock.h> +#include <linux/rtnetlink.h> + +/* + NOTE. The most unpleasent question is serialization of + accesses to resolved addresses. The problem is that addresses + are modified by bh, but they are referenced from normal + kernel thread. Before today no locking was made. + My reasoning was that corrupted address token will be copied + to packet with cosmologically small probability + (it is even difficult to estimate such small number) + and it is very silly to waste cycles in fast path to lock them. + + But now I changed my mind, but not because previous statement + is wrong. Actually, neigh->ha MAY BE not opaque byte array, + but reference to some private data. In this case even neglibible + corruption probability becomes bug. + + - hh cache is protected by rwlock. It assumes that + hh cache update procedure is short and fast, and that + read_lock is cheaper than start_bh_atomic(). + - ha tokens, saved in neighbour entries, are protected + by bh_atomic(). + - no protection is made in /proc reading. It is OK, because + /proc is broken by design in any case, and + corrupted output is normal behaviour there. + + --ANK (981025) + */ + +#define NEIGH_DEBUG 1 + +#define NEIGH_PRINTK(x...) printk(x) +#define NEIGH_NOPRINTK(x...) do { ; } while(0) +#define NEIGH_PRINTK0 NEIGH_PRINTK +#define NEIGH_PRINTK1 NEIGH_NOPRINTK +#define NEIGH_PRINTK2 NEIGH_NOPRINTK + +#if NEIGH_DEBUG >= 1 +#undef NEIGH_PRINTK1 +#define NEIGH_PRINTK1 NEIGH_PRINTK +#endif +#if NEIGH_DEBUG >= 2 +#undef NEIGH_PRINTK2 +#define NEIGH_PRINTK2 NEIGH_PRINTK +#endif + +static void neigh_timer_handler(unsigned long arg); +#ifdef CONFIG_ARPD +static void neigh_app_notify(struct neighbour *n); +#endif +static int pneigh_ifdown(struct neigh_table *tbl, struct device *dev); + +static int neigh_glbl_allocs; +static struct neigh_table *neigh_tables; + +static int neigh_blackhole(struct sk_buff *skb) +{ + kfree_skb(skb); + return -ENETDOWN; +} + +/* + * It is random distribution in the interval (1/2)*base...(3/2)*base. + * It corresponds to default IPv6 settings and is not overridable, + * because it is really reasonbale choice. + */ + +unsigned long neigh_rand_reach_time(unsigned long base) +{ + return (net_random() % base) + (base>>1); +} + + +static int neigh_forced_gc(struct neigh_table *tbl) +{ + int shrunk = 0; + int i; + + if (atomic_read(&tbl->lock)) + return 0; + + for (i=0; i<=NEIGH_HASHMASK; i++) { + struct neighbour *n, **np; + + np = &tbl->hash_buckets[i]; + while ((n = *np) != NULL) { + /* Neighbour record may be discarded if: + - nobody refers to it. + - it is not premanent + - (NEW and probably wrong) + INCOMPLETE entries are kept at least for + n->parms->retrans_time, otherwise we could + flood network with resolution requests. + It is not clear, what is better table overflow + or flooding. + */ + if (atomic_read(&n->refcnt) == 0 && + !(n->nud_state&NUD_PERMANENT) && + (n->nud_state != NUD_INCOMPLETE || + jiffies - n->used > n->parms->retrans_time)) { + *np = n->next; + n->tbl = NULL; + tbl->entries--; + shrunk = 1; + neigh_destroy(n); + continue; + } + np = &n->next; + } + } + + tbl->last_flush = jiffies; + return shrunk; +} + +int neigh_ifdown(struct neigh_table *tbl, struct device *dev) +{ + int i; + + if (atomic_read(&tbl->lock)) { + NEIGH_PRINTK1("neigh_ifdown: impossible event 1763\n"); + return -EBUSY; + } + + start_bh_atomic(); + for (i=0; i<=NEIGH_HASHMASK; i++) { + struct neighbour *n, **np; + + np = &tbl->hash_buckets[i]; + while ((n = *np) != NULL) { + if (dev && n->dev != dev) { + np = &n->next; + continue; + } + *np = n->next; + n->tbl = NULL; + tbl->entries--; + if (atomic_read(&n->refcnt)) { + /* The most unpleasant situation. + We must destroy neighbour entry, + but someone still uses it. + + The destroy will be delayed until + the last user releases us, but + we must kill timers etc. and move + it to safe state. + */ + if (n->nud_state & NUD_IN_TIMER) + del_timer(&n->timer); + n->parms = &tbl->parms; + skb_queue_purge(&n->arp_queue); + n->output = neigh_blackhole; + if (n->nud_state&NUD_VALID) + n->nud_state = NUD_NOARP; + else + n->nud_state = NUD_NONE; + NEIGH_PRINTK2("neigh %p is stray.\n", n); + } else + neigh_destroy(n); + } + } + + del_timer(&tbl->proxy_timer); + skb_queue_purge(&tbl->proxy_queue); + pneigh_ifdown(tbl, dev); + end_bh_atomic(); + return 0; +} + +static struct neighbour *neigh_alloc(struct neigh_table *tbl, int creat) +{ + struct neighbour *n; + unsigned long now = jiffies; + + if (tbl->entries > tbl->gc_thresh1) { + if (creat < 0) + return NULL; + if (tbl->entries > tbl->gc_thresh3 || + (tbl->entries > tbl->gc_thresh2 && + now - tbl->last_flush > 5*HZ)) { + if (neigh_forced_gc(tbl) == 0 && + tbl->entries > tbl->gc_thresh3) + return NULL; + } + } + + n = kmalloc(tbl->entry_size, GFP_ATOMIC); + if (n == NULL) + return NULL; + + memset(n, 0, tbl->entry_size); + + skb_queue_head_init(&n->arp_queue); + n->updated = n->used = now; + n->nud_state = NUD_NONE; + n->output = neigh_blackhole; + n->parms = &tbl->parms; + init_timer(&n->timer); + n->timer.function = neigh_timer_handler; + n->timer.data = (unsigned long)n; + tbl->stats.allocs++; + neigh_glbl_allocs++; + return n; +} + + +struct neighbour * __neigh_lookup(struct neigh_table *tbl, const void *pkey, + struct device *dev, int creat) +{ + struct neighbour *n; + u32 hash_val; + int key_len = tbl->key_len; + + hash_val = *(u32*)(pkey + key_len - 4); + hash_val ^= (hash_val>>16); + hash_val ^= hash_val>>8; + hash_val ^= hash_val>>3; + hash_val = (hash_val^dev->ifindex)&NEIGH_HASHMASK; + + for (n = tbl->hash_buckets[hash_val]; n; n = n->next) { + if (dev == n->dev && + memcmp(n->primary_key, pkey, key_len) == 0) { + atomic_inc(&n->refcnt); + return n; + } + } + if (!creat) + return NULL; + + n = neigh_alloc(tbl, creat); + if (n == NULL) + return NULL; + + memcpy(n->primary_key, pkey, key_len); + n->dev = dev; + + /* Protocol specific setup. */ + if (tbl->constructor && tbl->constructor(n) < 0) { + neigh_destroy(n); + return NULL; + } + + /* Device specific setup. */ + if (n->parms && n->parms->neigh_setup && n->parms->neigh_setup(n) < 0) { + neigh_destroy(n); + return NULL; + } + + n->confirmed = jiffies - (n->parms->base_reachable_time<<1); + atomic_set(&n->refcnt, 1); + tbl->entries++; + n->next = tbl->hash_buckets[hash_val]; + tbl->hash_buckets[hash_val] = n; + n->tbl = tbl; + NEIGH_PRINTK2("neigh %p is created.\n", n); + return n; +} + +struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl, const void *pkey, + struct device *dev, int creat) +{ + struct pneigh_entry *n; + u32 hash_val; + int key_len = tbl->key_len; + + hash_val = *(u32*)(pkey + key_len - 4); + hash_val ^= (hash_val>>16); + hash_val ^= hash_val>>8; + hash_val ^= hash_val>>4; + hash_val &= PNEIGH_HASHMASK; + + for (n = tbl->phash_buckets[hash_val]; n; n = n->next) { + if (memcmp(n->key, pkey, key_len) == 0 && + (n->dev == dev || !n->dev)) + return n; + } + if (!creat) + return NULL; + + n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL); + if (n == NULL) + return NULL; + + memcpy(n->key, pkey, key_len); + n->dev = dev; + + if (tbl->pconstructor && tbl->pconstructor(n)) { + kfree(n); + return NULL; + } + + n->next = tbl->phash_buckets[hash_val]; + tbl->phash_buckets[hash_val] = n; + return n; +} + + +int pneigh_delete(struct neigh_table *tbl, const void *pkey, struct device *dev) +{ + struct pneigh_entry *n, **np; + u32 hash_val; + int key_len = tbl->key_len; + + hash_val = *(u32*)(pkey + key_len - 4); + hash_val ^= (hash_val>>16); + hash_val ^= hash_val>>8; + hash_val ^= hash_val>>4; + hash_val &= PNEIGH_HASHMASK; + + for (np = &tbl->phash_buckets[hash_val]; (n=*np) != NULL; np = &n->next) { + if (memcmp(n->key, pkey, key_len) == 0 && n->dev == dev) { + *np = n->next; + synchronize_bh(); + if (tbl->pdestructor) + tbl->pdestructor(n); + kfree(n); + return 0; + } + } + return -ENOENT; +} + +static int pneigh_ifdown(struct neigh_table *tbl, struct device *dev) +{ + struct pneigh_entry *n, **np; + u32 h; + + for (h=0; h<=PNEIGH_HASHMASK; h++) { + np = &tbl->phash_buckets[h]; + while ((n=*np) != NULL) { + if (n->dev == dev || dev == NULL) { + *np = n->next; + synchronize_bh(); + if (tbl->pdestructor) + tbl->pdestructor(n); + kfree(n); + continue; + } + np = &n->next; + } + } + return -ENOENT; +} + + +/* + * neighbour must already be out of the table; + * + */ +void neigh_destroy(struct neighbour *neigh) +{ + struct hh_cache *hh; + + if (neigh->tbl || atomic_read(&neigh->refcnt)) { + NEIGH_PRINTK1("neigh_destroy: neighbour is use tbl=%p, ref=%d: " + "called from %p\n", neigh->tbl, atomic_read(&neigh->refcnt), __builtin_return_address(0)); + return; + } + + if (neigh->nud_state&NUD_IN_TIMER) + del_timer(&neigh->timer); + + while ((hh = neigh->hh) != NULL) { + neigh->hh = hh->hh_next; + hh->hh_next = NULL; + hh->hh_output = neigh_blackhole; + if (atomic_dec_and_test(&hh->hh_refcnt)) + kfree(hh); + } + + if (neigh->ops && neigh->ops->destructor) + (neigh->ops->destructor)(neigh); + + skb_queue_purge(&neigh->arp_queue); + + NEIGH_PRINTK2("neigh %p is destroyed.\n", neigh); + + neigh_glbl_allocs--; + kfree(neigh); +} + +/* Neighbour state is suspicious; + disable fast path. + */ +static void neigh_suspect(struct neighbour *neigh) +{ + struct hh_cache *hh; + + NEIGH_PRINTK2("neigh %p is suspecteded.\n", neigh); + + neigh->output = neigh->ops->output; + + for (hh = neigh->hh; hh; hh = hh->hh_next) + hh->hh_output = neigh->ops->output; +} + +/* Neighbour state is OK; + enable fast path. + */ +static void neigh_connect(struct neighbour *neigh) +{ + struct hh_cache *hh; + + NEIGH_PRINTK2("neigh %p is connected.\n", neigh); + + neigh->output = neigh->ops->connected_output; + + for (hh = neigh->hh; hh; hh = hh->hh_next) + hh->hh_output = neigh->ops->hh_output; +} + +/* + Transitions NUD_STALE <-> NUD_REACHABLE do not occur + when fast path is built: we have no timers assotiated with + these states, we do not have time to check state when sending. + neigh_periodic_timer check periodically neigh->confirmed + time and moves NUD_REACHABLE -> NUD_STALE. + + If a routine wants to know TRUE entry state, it calls + neigh_sync before checking state. + */ + +static void neigh_sync(struct neighbour *n) +{ + unsigned long now = jiffies; + u8 state = n->nud_state; + + if (state&(NUD_NOARP|NUD_PERMANENT)) + return; + if (state&NUD_REACHABLE) { + if (now - n->confirmed > n->parms->reachable_time) { + n->nud_state = NUD_STALE; + neigh_suspect(n); + } + } else if (state&NUD_VALID) { + if (now - n->confirmed < n->parms->reachable_time) { + if (state&NUD_IN_TIMER) + del_timer(&n->timer); + n->nud_state = NUD_REACHABLE; + neigh_connect(n); + } + } +} + +static void neigh_periodic_timer(unsigned long arg) +{ + struct neigh_table *tbl = (struct neigh_table*)arg; + unsigned long now = jiffies; + int i; + + if (atomic_read(&tbl->lock)) { + tbl->gc_timer.expires = now + 1*HZ; + add_timer(&tbl->gc_timer); + return; + } + + /* + * periodicly recompute ReachableTime from random function + */ + + if (now - tbl->last_rand > 300*HZ) { + struct neigh_parms *p; + tbl->last_rand = now; + for (p=&tbl->parms; p; p = p->next) + p->reachable_time = neigh_rand_reach_time(p->base_reachable_time); + } + + for (i=0; i <= NEIGH_HASHMASK; i++) { + struct neighbour *n, **np; + + np = &tbl->hash_buckets[i]; + while ((n = *np) != NULL) { + unsigned state = n->nud_state; + + if (state&(NUD_PERMANENT|NUD_IN_TIMER)) + goto next_elt; + + if ((long)(n->used - n->confirmed) < 0) + n->used = n->confirmed; + + if (atomic_read(&n->refcnt) == 0 && + (state == NUD_FAILED || now - n->used > n->parms->gc_staletime)) { + *np = n->next; + n->tbl = NULL; + n->next = NULL; + tbl->entries--; + neigh_destroy(n); + continue; + } + + if (n->nud_state&NUD_REACHABLE && + now - n->confirmed > n->parms->reachable_time) { + n->nud_state = NUD_STALE; + neigh_suspect(n); + } + +next_elt: + np = &n->next; + } + } + + tbl->gc_timer.expires = now + tbl->gc_interval; + add_timer(&tbl->gc_timer); +} + +static __inline__ int neigh_max_probes(struct neighbour *n) +{ + struct neigh_parms *p = n->parms; + return p->ucast_probes + p->app_probes + p->mcast_probes; +} + + +/* Called when a timer expires for a neighbour entry. */ + +static void neigh_timer_handler(unsigned long arg) +{ + unsigned long now = jiffies; + struct neighbour *neigh = (struct neighbour*)arg; + unsigned state = neigh->nud_state; + + if (!(state&NUD_IN_TIMER)) { + NEIGH_PRINTK1("neigh: timer & !nud_in_timer\n"); + return; + } + + if ((state&NUD_VALID) && + now - neigh->confirmed < neigh->parms->reachable_time) { + neigh->nud_state = NUD_REACHABLE; + NEIGH_PRINTK2("neigh %p is still alive.\n", neigh); + neigh_connect(neigh); + return; + } + if (state == NUD_DELAY) { + NEIGH_PRINTK2("neigh %p is probed.\n", neigh); + neigh->nud_state = NUD_PROBE; + neigh->probes = 0; + } + + if (neigh->probes >= neigh_max_probes(neigh)) { + struct sk_buff *skb; + + neigh->nud_state = NUD_FAILED; + neigh->tbl->stats.res_failed++; + NEIGH_PRINTK2("neigh %p is failed.\n", neigh); + + /* It is very thin place. report_unreachable is very complicated + routine. Particularly, it can hit the same neighbour entry! + + So that, we try to be accurate and avoid dead loop. --ANK + */ + while(neigh->nud_state==NUD_FAILED && (skb=__skb_dequeue(&neigh->arp_queue)) != NULL) + neigh->ops->error_report(neigh, skb); + skb_queue_purge(&neigh->arp_queue); + return; + } + + neigh->timer.expires = now + neigh->parms->retrans_time; + add_timer(&neigh->timer); + + neigh->ops->solicit(neigh, skb_peek(&neigh->arp_queue)); + neigh->probes++; +} + +int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) +{ + start_bh_atomic(); + if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) { + if (!(neigh->nud_state&(NUD_STALE|NUD_INCOMPLETE))) { + if (neigh->tbl == NULL) { + NEIGH_PRINTK2("neigh %p used after death.\n", neigh); + if (skb) + kfree_skb(skb); + end_bh_atomic(); + return 1; + } + if (neigh->parms->mcast_probes + neigh->parms->app_probes) { + neigh->probes = neigh->parms->ucast_probes; + neigh->nud_state = NUD_INCOMPLETE; + neigh->timer.expires = jiffies + neigh->parms->retrans_time; + add_timer(&neigh->timer); + + neigh->ops->solicit(neigh, skb); + neigh->probes++; + } else { + neigh->nud_state = NUD_FAILED; + if (skb) + kfree_skb(skb); + end_bh_atomic(); + return 1; + } + } + if (neigh->nud_state == NUD_INCOMPLETE) { + if (skb) { + if (skb_queue_len(&neigh->arp_queue) >= neigh->parms->queue_len) { + struct sk_buff *buff; + buff = neigh->arp_queue.prev; + __skb_unlink(buff, &neigh->arp_queue); + kfree_skb(buff); + } + __skb_queue_head(&neigh->arp_queue, skb); + } + end_bh_atomic(); + return 1; + } + if (neigh->nud_state == NUD_STALE) { + NEIGH_PRINTK2("neigh %p is delayed.\n", neigh); + neigh->nud_state = NUD_DELAY; + neigh->timer.expires = jiffies + neigh->parms->delay_probe_time; + add_timer(&neigh->timer); + } + } + end_bh_atomic(); + return 0; +} + +static __inline__ void neigh_update_hhs(struct neighbour *neigh) +{ + struct hh_cache *hh; + void (*update)(struct hh_cache*, struct device*, unsigned char*) = + neigh->dev->header_cache_update; + + if (update) { + for (hh=neigh->hh; hh; hh=hh->hh_next) { + write_lock_irq(&hh->hh_lock); + update(hh, neigh->dev, neigh->ha); + write_unlock_irq(&hh->hh_lock); + } + } +} + + + +/* Generic update routine. + -- lladdr is new lladdr or NULL, if it is not supplied. + -- new is new state. + -- override==1 allows to override existing lladdr, if it is different. + -- arp==0 means that the change is administrative. + */ + +int neigh_update(struct neighbour *neigh, u8 *lladdr, u8 new, int override, int arp) +{ + u8 old = neigh->nud_state; + struct device *dev = neigh->dev; + + if (arp && (old&(NUD_NOARP|NUD_PERMANENT))) + return -EPERM; + + if (!(new&NUD_VALID)) { + if (old&NUD_IN_TIMER) + del_timer(&neigh->timer); + if (old&NUD_CONNECTED) + neigh_suspect(neigh); + neigh->nud_state = new; + return 0; + } + + /* Compare new lladdr with cached one */ + if (dev->addr_len == 0) { + /* First case: device needs no address. */ + lladdr = neigh->ha; + } else if (lladdr) { + /* The second case: if something is already cached + and a new address is proposed: + - compare new & old + - if they are different, check override flag + */ + if (old&NUD_VALID) { + if (memcmp(lladdr, neigh->ha, dev->addr_len) == 0) + lladdr = neigh->ha; + else if (!override) + return -EPERM; + } + } else { + /* No address is supplied; if we know something, + use it, otherwise discard the request. + */ + if (!(old&NUD_VALID)) + return -EINVAL; + lladdr = neigh->ha; + } + + neigh_sync(neigh); + old = neigh->nud_state; + if (new&NUD_CONNECTED) + neigh->confirmed = jiffies; + neigh->updated = jiffies; + + /* If entry was valid and address is not changed, + do not change entry state, if new one is STALE. + */ + if (old&NUD_VALID) { + if (lladdr == neigh->ha) + if (new == old || (new == NUD_STALE && (old&NUD_CONNECTED))) + return 0; + } + if (old&NUD_IN_TIMER) + del_timer(&neigh->timer); + neigh->nud_state = new; + if (lladdr != neigh->ha) { + memcpy(&neigh->ha, lladdr, dev->addr_len); + neigh_update_hhs(neigh); + neigh->confirmed = jiffies - (neigh->parms->base_reachable_time<<1); +#ifdef CONFIG_ARPD + if (neigh->parms->app_probes) + neigh_app_notify(neigh); +#endif + } + if (new == old) + return 0; + if (new&NUD_CONNECTED) + neigh_connect(neigh); + else + neigh_suspect(neigh); + if (!(old&NUD_VALID)) { + struct sk_buff *skb; + + /* Again: avoid dead loop if something went wrong */ + + while (neigh->nud_state&NUD_VALID && + (skb=__skb_dequeue(&neigh->arp_queue)) != NULL) { + struct neighbour *n1 = neigh; + /* On shaper/eql skb->dst->neighbour != neigh :( */ + if (skb->dst && skb->dst->neighbour) + n1 = skb->dst->neighbour; + n1->output(skb); + } + skb_queue_purge(&neigh->arp_queue); + } + return 0; +} + +struct neighbour * neigh_event_ns(struct neigh_table *tbl, + u8 *lladdr, void *saddr, + struct device *dev) +{ + struct neighbour *neigh; + + neigh = __neigh_lookup(tbl, saddr, dev, lladdr || !dev->addr_len); + if (neigh) + neigh_update(neigh, lladdr, NUD_STALE, 1, 1); + return neigh; +} + +static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst, u16 protocol) +{ + struct hh_cache *hh = NULL; + struct device *dev = dst->dev; + + for (hh=n->hh; hh; hh = hh->hh_next) + if (hh->hh_type == protocol) + break; + + if (!hh && (hh = kmalloc(sizeof(*hh), GFP_ATOMIC)) != NULL) { + memset(hh, 0, sizeof(struct hh_cache)); + hh->hh_type = protocol; + atomic_set(&hh->hh_refcnt, 0); + hh->hh_next = NULL; + if (dev->hard_header_cache(n, hh)) { + kfree(hh); + hh = NULL; + } else { + atomic_inc(&hh->hh_refcnt); + hh->hh_next = n->hh; + n->hh = hh; + if (n->nud_state&NUD_CONNECTED) + hh->hh_output = n->ops->hh_output; + else + hh->hh_output = n->ops->output; + } + } + if (hh) { + atomic_inc(&hh->hh_refcnt); + dst->hh = hh; + } +} + +/* This function can be used in contexts, where only old dev_queue_xmit + worked, f.e. if you want to override normal output path (eql, shaper), + but resoltution is not made yet. + */ + +int neigh_compat_output(struct sk_buff *skb) +{ + struct device *dev = skb->dev; + + __skb_pull(skb, skb->nh.raw - skb->data); + + if (dev->hard_header && + dev->hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL, skb->len) < 0 && + dev->rebuild_header(skb)) + return 0; + + return dev_queue_xmit(skb); +} + +/* Slow and careful. */ + +int neigh_resolve_output(struct sk_buff *skb) +{ + struct dst_entry *dst = skb->dst; + struct neighbour *neigh; + + if (!dst || !(neigh = dst->neighbour)) + goto discard; + + __skb_pull(skb, skb->nh.raw - skb->data); + + if (neigh_event_send(neigh, skb) == 0) { + int err; + struct device *dev = neigh->dev; + if (dev->hard_header_cache && dst->hh == NULL) { + start_bh_atomic(); + if (dst->hh == NULL) + neigh_hh_init(neigh, dst, dst->ops->protocol); + err = dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); + end_bh_atomic(); + } else { + start_bh_atomic(); + err = dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); + end_bh_atomic(); + } + if (err >= 0) + return neigh->ops->queue_xmit(skb); + kfree_skb(skb); + return -EINVAL; + } + return 0; + +discard: + NEIGH_PRINTK1("neigh_resolve_output: dst=%p neigh=%p\n", dst, dst ? dst->neighbour : NULL); + kfree_skb(skb); + return -EINVAL; +} + +/* As fast as possible without hh cache */ + +int neigh_connected_output(struct sk_buff *skb) +{ + int err; + struct dst_entry *dst = skb->dst; + struct neighbour *neigh = dst->neighbour; + struct device *dev = neigh->dev; + + __skb_pull(skb, skb->nh.raw - skb->data); + + start_bh_atomic(); + err = dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); + end_bh_atomic(); + if (err >= 0) + return neigh->ops->queue_xmit(skb); + kfree_skb(skb); + return -EINVAL; +} + +static void neigh_proxy_process(unsigned long arg) +{ + struct neigh_table *tbl = (struct neigh_table *)arg; + long sched_next = 0; + unsigned long now = jiffies; + struct sk_buff *skb = tbl->proxy_queue.next; + + while (skb != (struct sk_buff*)&tbl->proxy_queue) { + struct sk_buff *back = skb; + long tdif = back->stamp.tv_usec - now; + + skb = skb->next; + if (tdif <= 0) { + __skb_unlink(back, &tbl->proxy_queue); + if (tbl->proxy_redo) + tbl->proxy_redo(back); + else + kfree_skb(back); + } else if (!sched_next || tdif < sched_next) + sched_next = tdif; + } + del_timer(&tbl->proxy_timer); + if (sched_next) { + tbl->proxy_timer.expires = jiffies + sched_next; + add_timer(&tbl->proxy_timer); + } +} + +void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, + struct sk_buff *skb) +{ + unsigned long now = jiffies; + long sched_next = net_random()%p->proxy_delay; + + if (tbl->proxy_queue.qlen > p->proxy_qlen) { + kfree_skb(skb); + return; + } + skb->stamp.tv_sec = 0; + skb->stamp.tv_usec = now + sched_next; + if (del_timer(&tbl->proxy_timer)) { + long tval = tbl->proxy_timer.expires - now; + if (tval < sched_next) + sched_next = tval; + } + tbl->proxy_timer.expires = now + sched_next; + dst_release(skb->dst); + skb->dst = NULL; + __skb_queue_tail(&tbl->proxy_queue, skb); + add_timer(&tbl->proxy_timer); +} + + +struct neigh_parms *neigh_parms_alloc(struct device *dev, struct neigh_table *tbl) +{ + struct neigh_parms *p; + p = kmalloc(sizeof(*p), GFP_KERNEL); + if (p) { + memcpy(p, &tbl->parms, sizeof(*p)); + p->tbl = tbl; + p->reachable_time = neigh_rand_reach_time(p->base_reachable_time); + if (dev && dev->neigh_setup) { + if (dev->neigh_setup(dev, p)) { + kfree(p); + return NULL; + } + } + p->next = tbl->parms.next; + tbl->parms.next = p; + } + return p; +} + +void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms) +{ + struct neigh_parms **p; + + if (parms == NULL || parms == &tbl->parms) + return; + for (p = &tbl->parms.next; *p; p = &(*p)->next) { + if (*p == parms) { + *p = parms->next; + synchronize_bh(); +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(parms); +#endif + kfree(parms); + return; + } + } + NEIGH_PRINTK1("neigh_release_parms: not found\n"); +} + + +void neigh_table_init(struct neigh_table *tbl) +{ + unsigned long now = jiffies; + + tbl->parms.reachable_time = neigh_rand_reach_time(tbl->parms.base_reachable_time); + + init_timer(&tbl->gc_timer); + tbl->gc_timer.data = (unsigned long)tbl; + tbl->gc_timer.function = neigh_periodic_timer; + tbl->gc_timer.expires = now + tbl->gc_interval + tbl->parms.reachable_time; + add_timer(&tbl->gc_timer); + + init_timer(&tbl->proxy_timer); + tbl->proxy_timer.data = (unsigned long)tbl; + tbl->proxy_timer.function = neigh_proxy_process; + skb_queue_head_init(&tbl->proxy_queue); + + tbl->last_flush = now; + tbl->last_rand = now + tbl->parms.reachable_time*20; + tbl->next = neigh_tables; + neigh_tables = tbl; +} + +int neigh_table_clear(struct neigh_table *tbl) +{ + struct neigh_table **tp; + + start_bh_atomic(); + del_timer(&tbl->gc_timer); + del_timer(&tbl->proxy_timer); + skb_queue_purge(&tbl->proxy_queue); + neigh_ifdown(tbl, NULL); + end_bh_atomic(); + if (tbl->entries) + printk(KERN_CRIT "neighbour leakage\n"); + for (tp = &neigh_tables; *tp; tp = &(*tp)->next) { + if (*tp == tbl) { + *tp = tbl->next; + synchronize_bh(); + break; + } + } +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&tbl->parms); +#endif + return 0; +} + +#ifdef CONFIG_RTNETLINK + + +int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) +{ + struct ndmsg *ndm = NLMSG_DATA(nlh); + struct rtattr **nda = arg; + struct neigh_table *tbl; + struct device *dev = NULL; + + if (ndm->ndm_ifindex) { + if ((dev = dev_get_by_index(ndm->ndm_ifindex)) == NULL) + return -ENODEV; + } + + for (tbl=neigh_tables; tbl; tbl = tbl->next) { + int err = 0; + struct neighbour *n; + + if (tbl->family != ndm->ndm_family) + continue; + + if (nda[NDA_DST-1] == NULL || + nda[NDA_DST-1]->rta_len != RTA_LENGTH(tbl->key_len)) + return -EINVAL; + + if (ndm->ndm_flags&NTF_PROXY) + return pneigh_delete(tbl, RTA_DATA(nda[NDA_DST-1]), dev); + + if (dev == NULL) + return -EINVAL; + + start_bh_atomic(); + n = __neigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev, 0); + if (n) { + err = neigh_update(n, NULL, NUD_FAILED, 1, 0); + neigh_release(n); + } + end_bh_atomic(); + return err; + } + + return -EADDRNOTAVAIL; +} + +int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) +{ + struct ndmsg *ndm = NLMSG_DATA(nlh); + struct rtattr **nda = arg; + struct neigh_table *tbl; + struct device *dev = NULL; + + if (ndm->ndm_ifindex) { + if ((dev = dev_get_by_index(ndm->ndm_ifindex)) == NULL) + return -ENODEV; + } + + for (tbl=neigh_tables; tbl; tbl = tbl->next) { + int err = 0; + struct neighbour *n; + + if (tbl->family != ndm->ndm_family) + continue; + if (nda[NDA_DST-1] == NULL || + nda[NDA_DST-1]->rta_len != RTA_LENGTH(tbl->key_len)) + return -EINVAL; + if (ndm->ndm_flags&NTF_PROXY) { + if (pneigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev, 1)) + return 0; + return -ENOBUFS; + } + if (dev == NULL) + return -EINVAL; + if (nda[NDA_LLADDR-1] != NULL && + nda[NDA_LLADDR-1]->rta_len != RTA_LENGTH(dev->addr_len)) + return -EINVAL; + start_bh_atomic(); + n = __neigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev, 0); + if (n) { + if (nlh->nlmsg_flags&NLM_F_EXCL) + err = -EEXIST; + } else if (!(nlh->nlmsg_flags&NLM_F_CREATE)) + err = -ENOENT; + else { + n = __neigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev, 1); + if (n == NULL) + err = -ENOBUFS; + } + if (err == 0) { + err = neigh_update(n, nda[NDA_LLADDR-1] ? RTA_DATA(nda[NDA_LLADDR-1]) : NULL, + ndm->ndm_state, + nlh->nlmsg_flags&NLM_F_REPLACE, 0); + } + if (n) + neigh_release(n); + end_bh_atomic(); + return err; + } + + return -EADDRNOTAVAIL; +} + + +static int neigh_fill_info(struct sk_buff *skb, struct neighbour *n, + u32 pid, u32 seq, int event) +{ + unsigned long now = jiffies; + struct ndmsg *ndm; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + struct nda_cacheinfo ci; + + nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*ndm)); + ndm = NLMSG_DATA(nlh); + ndm->ndm_family = n->ops->family; + ndm->ndm_flags = n->flags; + ndm->ndm_type = n->type; + ndm->ndm_state = n->nud_state; + ndm->ndm_ifindex = n->dev->ifindex; + RTA_PUT(skb, NDA_DST, n->tbl->key_len, n->primary_key); + if (n->nud_state&NUD_VALID) + RTA_PUT(skb, NDA_LLADDR, n->dev->addr_len, n->ha); + ci.ndm_used = now - n->used; + ci.ndm_confirmed = now - n->confirmed; + ci.ndm_updated = now - n->updated; + ci.ndm_refcnt = atomic_read(&n->refcnt); + RTA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci); + nlh->nlmsg_len = skb->tail - b; + return skb->len; + +nlmsg_failure: +rtattr_failure: + skb_trim(skb, b - skb->data); + return -1; +} + + +static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, struct netlink_callback *cb) +{ + struct neighbour *n; + int h, s_h; + int idx, s_idx; + + s_h = cb->args[1]; + s_idx = idx = cb->args[2]; + for (h=0; h <= NEIGH_HASHMASK; h++) { + if (h < s_h) continue; + if (h > s_h) + s_idx = 0; + start_bh_atomic(); + for (n = tbl->hash_buckets[h], idx = 0; n; + n = n->next, idx++) { + if (idx < s_idx) + continue; + if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, RTM_NEWNEIGH) <= 0) { + end_bh_atomic(); + cb->args[1] = h; + cb->args[2] = idx; + return -1; + } + } + end_bh_atomic(); + } + + cb->args[1] = h; + cb->args[2] = idx; + return skb->len; +} + +int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) +{ + int t; + int s_t; + struct neigh_table *tbl; + int family = ((struct rtgenmsg*)NLMSG_DATA(cb->nlh))->rtgen_family; + + s_t = cb->args[0]; + + for (tbl=neigh_tables, t=0; tbl; tbl = tbl->next, t++) { + if (t < s_t) continue; + if (family && tbl->family != family) + continue; + if (t > s_t) + memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); + if (neigh_dump_table(tbl, skb, cb) < 0) + break; + } + + cb->args[0] = t; + + return skb->len; +} + +#ifdef CONFIG_ARPD +void neigh_app_ns(struct neighbour *n) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + int size = NLMSG_SPACE(sizeof(struct ndmsg)+256); + + skb = alloc_skb(size, GFP_ATOMIC); + if (!skb) + return; + + if (neigh_fill_info(skb, n, 0, 0, RTM_GETNEIGH) < 0) { + kfree_skb(skb); + return; + } + nlh = (struct nlmsghdr*)skb->data; + nlh->nlmsg_flags = NLM_F_REQUEST; + NETLINK_CB(skb).dst_groups = RTMGRP_NEIGH; + netlink_broadcast(rtnl, skb, 0, RTMGRP_NEIGH, GFP_ATOMIC); +} + +static void neigh_app_notify(struct neighbour *n) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + int size = NLMSG_SPACE(sizeof(struct ndmsg)+256); + + skb = alloc_skb(size, GFP_ATOMIC); + if (!skb) + return; + + if (neigh_fill_info(skb, n, 0, 0, RTM_NEWNEIGH) < 0) { + kfree_skb(skb); + return; + } + nlh = (struct nlmsghdr*)skb->data; + NETLINK_CB(skb).dst_groups = RTMGRP_NEIGH; + netlink_broadcast(rtnl, skb, 0, RTMGRP_NEIGH, GFP_ATOMIC); +} + + + +#endif + + +#endif + +#ifdef CONFIG_SYSCTL + +struct neigh_sysctl_table +{ + struct ctl_table_header *sysctl_header; + ctl_table neigh_vars[17]; + ctl_table neigh_dev[2]; + ctl_table neigh_neigh_dir[2]; + ctl_table neigh_proto_dir[2]; + ctl_table neigh_root_dir[2]; +} neigh_sysctl_template = { + NULL, + {{NET_NEIGH_MCAST_SOLICIT, "mcast_solicit", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_UCAST_SOLICIT, "ucast_solicit", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_APP_SOLICIT, "app_solicit", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_RETRANS_TIME, "retrans_time", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_REACHABLE_TIME, "base_reachable_time", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec_jiffies}, + {NET_NEIGH_DELAY_PROBE_TIME, "delay_first_probe_time", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec_jiffies}, + {NET_NEIGH_GC_STALE_TIME, "gc_stale_time", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec_jiffies}, + {NET_NEIGH_UNRES_QLEN, "unres_qlen", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_PROXY_QLEN, "proxy_qlen", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_ANYCAST_DELAY, "anycast_delay", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_PROXY_DELAY, "proxy_delay", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_LOCKTIME, "locktime", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_GC_INTERVAL, "gc_interval", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec_jiffies}, + {NET_NEIGH_GC_THRESH1, "gc_thresh1", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_GC_THRESH2, "gc_thresh2", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {NET_NEIGH_GC_THRESH3, "gc_thresh3", + NULL, sizeof(int), 0644, NULL, + &proc_dointvec}, + {0}}, + + {{NET_PROTO_CONF_DEFAULT, "default", NULL, 0, 0555, NULL},{0}}, + {{0, "neigh", NULL, 0, 0555, NULL},{0}}, + {{0, NULL, NULL, 0, 0555, NULL},{0}}, + {{CTL_NET, "net", NULL, 0, 0555, NULL},{0}} +}; + +int neigh_sysctl_register(struct device *dev, struct neigh_parms *p, + int p_id, int pdev_id, char *p_name) +{ + struct neigh_sysctl_table *t; + + t = kmalloc(sizeof(*t), GFP_KERNEL); + if (t == NULL) + return -ENOBUFS; + memcpy(t, &neigh_sysctl_template, sizeof(*t)); + t->neigh_vars[0].data = &p->mcast_probes; + t->neigh_vars[1].data = &p->ucast_probes; + t->neigh_vars[2].data = &p->app_probes; + t->neigh_vars[3].data = &p->retrans_time; + t->neigh_vars[4].data = &p->base_reachable_time; + t->neigh_vars[5].data = &p->delay_probe_time; + t->neigh_vars[6].data = &p->gc_staletime; + t->neigh_vars[7].data = &p->queue_len; + t->neigh_vars[8].data = &p->proxy_qlen; + t->neigh_vars[9].data = &p->anycast_delay; + t->neigh_vars[10].data = &p->proxy_delay; + t->neigh_vars[11].data = &p->locktime; + if (dev) { + t->neigh_dev[0].procname = dev->name; + t->neigh_dev[0].ctl_name = dev->ifindex; + memset(&t->neigh_vars[12], 0, sizeof(ctl_table)); + } else { + t->neigh_vars[12].data = (int*)(p+1); + t->neigh_vars[13].data = (int*)(p+1) + 1; + t->neigh_vars[14].data = (int*)(p+1) + 2; + t->neigh_vars[15].data = (int*)(p+1) + 3; + } + t->neigh_neigh_dir[0].ctl_name = pdev_id; + + t->neigh_proto_dir[0].procname = p_name; + t->neigh_proto_dir[0].ctl_name = p_id; + + t->neigh_dev[0].child = t->neigh_vars; + t->neigh_neigh_dir[0].child = t->neigh_dev; + t->neigh_proto_dir[0].child = t->neigh_neigh_dir; + t->neigh_root_dir[0].child = t->neigh_proto_dir; + + t->sysctl_header = register_sysctl_table(t->neigh_root_dir, 0); + if (t->sysctl_header == NULL) { + kfree(t); + return -ENOBUFS; + } + p->sysctl_table = t; + return 0; +} + +void neigh_sysctl_unregister(struct neigh_parms *p) +{ + if (p->sysctl_table) { + struct neigh_sysctl_table *t = p->sysctl_table; + p->sysctl_table = NULL; + unregister_sysctl_table(t->sysctl_header); + kfree(t); + } +} + +#endif /* CONFIG_SYSCTL */ |