/* net/atm/clip.c - RFC1577 Classical IP over ATM */ /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA * * Changes: * Harald Welte : * - backport DaveM's generalized neighbour cache from 2.6.9-rcX */ #include #include #include #include /* for UINT_MAX */ #include #include #include #include #include #include #include /* for some manifest constants */ #include #include #include #include #include #include /* for net/route.h */ #include /* for struct sockaddr_in */ #include /* for IFF_UP */ #include #include #include #include /* for struct rtable and routing */ #include /* icmp_send */ #include /* for HZ */ #include /* for htons etc. */ #include /* save/restore_flags */ #include #include #include "common.h" #include "resources.h" #include "ipcommon.h" #include #if 0 #define DPRINTK(format,args...) printk(format,##args) #else #define DPRINTK(format,args...) #endif struct net_device *clip_devs = NULL; struct atm_vcc *atmarpd = NULL; static struct neigh_table clip_tbl; static struct timer_list idle_timer; static int start_timer = 1; static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip) { struct atmarp_ctrl *ctrl; struct sk_buff *skb; DPRINTK("to_atmarpd(%d)\n",type); if (!atmarpd) return -EUNATCH; skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC); if (!skb) return -ENOMEM; ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl)); ctrl->type = type; ctrl->itf_num = itf; ctrl->ip = ip; atm_force_charge(atmarpd,skb->truesize); skb_queue_tail(&atmarpd->sk->receive_queue,skb); wake_up(&atmarpd->sleep); return 0; } static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry) { DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry, entry->neigh); clip_vcc->entry = entry; clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */ clip_vcc->next = entry->vccs; entry->vccs = clip_vcc; entry->neigh->used = jiffies; } static void unlink_clip_vcc(struct clip_vcc *clip_vcc) { struct atmarp_entry *entry = clip_vcc->entry; struct clip_vcc **walk; if (!entry) { printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc); return; } spin_lock_bh(&entry->neigh->dev->xmit_lock); /* block clip_start_xmit() */ entry->neigh->used = jiffies; for (walk = &entry->vccs; *walk; walk = &(*walk)->next) if (*walk == clip_vcc) { int error; *walk = clip_vcc->next; /* atomic */ clip_vcc->entry = NULL; if (clip_vcc->xoff) netif_wake_queue(entry->neigh->dev); if (entry->vccs) goto out; entry->expires = jiffies-1; /* force resolution or expiration */ error = neigh_update(entry->neigh,NULL,NUD_NONE,0,0); if (error) printk(KERN_CRIT "unlink_clip_vcc: " "neigh_update failed with %d\n",error); goto out; } printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc " "0x%p)\n",entry,clip_vcc); out: spin_unlock_bh(&entry->neigh->dev->xmit_lock); } /* The neighbour entry n->lock is held. */ static int neigh_check_cb(struct neighbour *n) { struct atmarp_entry *entry = NEIGH2ENTRY(n); struct clip_vcc *cv; for (cv = entry->vccs; cv; cv = cv->next) { unsigned long exp = cv->last_use + cv->idle_timeout; if (cv->idle_timeout && time_after(jiffies, exp)) { DPRINTK("releasing vcc %p->%p of entry %p\n", cv, cv->vcc, entry); vcc_release_async(cv->vcc, -ETIMEDOUT); } } if (entry->vccs || time_before(jiffies, entry->expires)) return 0; if (atomic_read(&n->refcnt) > 1) { struct sk_buff *skb; DPRINTK("destruction postponed with ref %d\n", atomic_read(&n->refcnt)); while ((skb = skb_dequeue(&n->arp_queue)) != NULL) dev_kfree_skb(skb); return 0; } DPRINTK("expired neigh %p\n",n); return 1; } static void idle_timer_check(unsigned long dummy) { write_lock(&clip_tbl.lock); __neigh_for_each_release(&clip_tbl, neigh_check_cb); mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ); write_unlock(&clip_tbl.lock); } static int clip_arp_rcv(struct sk_buff *skb) { struct atm_vcc *vcc; DPRINTK("clip_arp_rcv\n"); vcc = ATM_SKB(skb)->vcc; if (!vcc || !atm_charge(vcc,skb->truesize)) { dev_kfree_skb_any(skb); return 0; } DPRINTK("pushing to %p\n",vcc); DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push); CLIP_VCC(vcc)->old_push(vcc,skb); return 0; } static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb) { struct clip_vcc *clip_vcc = CLIP_VCC(vcc); DPRINTK("clip push\n"); if (!skb) { DPRINTK("removing VCC %p\n",clip_vcc); if (clip_vcc->entry) unlink_clip_vcc(clip_vcc); clip_vcc->old_push(vcc,NULL); /* pass on the bad news */ kfree(clip_vcc); return; } atm_return(vcc,skb->truesize); skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs; /* clip_vcc->entry == NULL if we don't have an IP address yet */ if (!skb->dev) { dev_kfree_skb_any(skb); return; } ATM_SKB(skb)->vcc = vcc; skb->mac.raw = skb->data; if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data, llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP); else { skb->protocol = ((u16 *) skb->data)[3]; skb_pull(skb,RFC1483LLC_LEN); if (skb->protocol == htons(ETH_P_ARP)) { PRIV(skb->dev)->stats.rx_packets++; PRIV(skb->dev)->stats.rx_bytes += skb->len; clip_arp_rcv(skb); return; } } clip_vcc->last_use = jiffies; PRIV(skb->dev)->stats.rx_packets++; PRIV(skb->dev)->stats.rx_bytes += skb->len; memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data)); netif_rx(skb); } /* * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that * clip_pop is atomic with respect to the critical section in clip_start_xmit. */ static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb) { struct clip_vcc *clip_vcc = CLIP_VCC(vcc); struct net_device *dev = skb->dev; int old; unsigned long flags; DPRINTK("clip_pop(vcc %p)\n",vcc); clip_vcc->old_pop(vcc,skb); /* skb->dev == NULL in outbound ARP packets */ if (!dev) return; spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags); if (atm_may_send(vcc,0)) { old = xchg(&clip_vcc->xoff,0); if (old) netif_wake_queue(dev); } spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags); } static void clip_neigh_destroy(struct neighbour *neigh) { DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh); if (NEIGH2ENTRY(neigh)->vccs) printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n"); NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef; } static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb) { DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb); to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip); } static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb) { #ifndef CONFIG_ATM_CLIP_NO_ICMP icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0); #endif kfree_skb(skb); } static struct neigh_ops clip_neigh_ops = { family: AF_INET, destructor: clip_neigh_destroy, solicit: clip_neigh_solicit, error_report: clip_neigh_error, output: dev_queue_xmit, connected_output: dev_queue_xmit, hh_output: dev_queue_xmit, queue_xmit: dev_queue_xmit, }; static int clip_constructor(struct neighbour *neigh) { struct atmarp_entry *entry = NEIGH2ENTRY(neigh); struct net_device *dev = neigh->dev; struct in_device *in_dev = dev->ip_ptr; DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry); if (!in_dev) return -EINVAL; neigh->type = inet_addr_type(entry->ip); if (neigh->type != RTN_UNICAST) return -EINVAL; if (in_dev->arp_parms) neigh->parms = in_dev->arp_parms; neigh->ops = &clip_neigh_ops; neigh->output = neigh->nud_state & NUD_VALID ? neigh->ops->connected_output : neigh->ops->output; entry->neigh = neigh; entry->vccs = NULL; entry->expires = jiffies-1; return 0; } static u32 clip_hash(const void *pkey, const struct net_device *dev) { return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd); } static struct neigh_table clip_tbl = { NULL, /* next */ AF_INET, /* family */ sizeof(struct neighbour)+sizeof(struct atmarp_entry), /* entry_size */ 4, /* key_len */ clip_hash, clip_constructor, /* constructor */ NULL, /* pconstructor */ NULL, /* pdestructor */ NULL, /* proxy_redo */ "clip_arp_cache", { /* neigh_parms */ NULL, /* next */ NULL, /* neigh_setup */ &clip_tbl, /* tbl */ 0, /* entries */ NULL, /* priv */ NULL, /* sysctl_table */ 30*HZ, /* base_reachable_time */ 1*HZ, /* retrans_time */ 60*HZ, /* gc_staletime */ 30*HZ, /* reachable_time */ 5*HZ, /* delay_probe_time */ 3, /* queue_len */ 3, /* ucast_probes */ 0, /* app_probes */ 3, /* mcast_probes */ 1*HZ, /* anycast_delay */ (8*HZ)/10, /* proxy_delay */ 1*HZ, /* proxy_qlen */ 64 /* locktime */ }, 30*HZ,128,512,1024 /* copied from ARP ... */ }; /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */ /* * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means * to allocate the neighbour entry but not to ask atmarpd for resolution. Also, * don't increment the usage count. This is used to create entries in * clip_setentry. */ static int clip_encap(struct atm_vcc *vcc,int mode) { CLIP_VCC(vcc)->encap = mode; return 0; } static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev) { struct clip_priv *clip_priv = PRIV(dev); struct atmarp_entry *entry; struct atm_vcc *vcc; int old; unsigned long flags; DPRINTK("clip_start_xmit (skb %p)\n",skb); if (!skb->dst) { printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n"); dev_kfree_skb(skb); clip_priv->stats.tx_dropped++; return 0; } if (!skb->dst->neighbour) { #if 0 skb->dst->neighbour = clip_find_neighbour(skb->dst,1); if (!skb->dst->neighbour) { dev_kfree_skb(skb); /* lost that one */ clip_priv->stats.tx_dropped++; return 0; } #endif printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n"); dev_kfree_skb(skb); clip_priv->stats.tx_dropped++; return 0; } entry = NEIGH2ENTRY(skb->dst->neighbour); if (!entry->vccs) { if (time_after(jiffies, entry->expires)) { /* should be resolved */ entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ; to_atmarpd(act_need,PRIV(dev)->number,entry->ip); } if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS) skb_queue_tail(&entry->neigh->arp_queue,skb); else { dev_kfree_skb(skb); clip_priv->stats.tx_dropped++; } return 0; } DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs); ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc; DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc); if (entry->vccs->encap) { void *here; here = skb_push(skb,RFC1483LLC_LEN); memcpy(here,llc_oui,sizeof(llc_oui)); ((u16 *) here)[3] = skb->protocol; } atomic_add(skb->truesize,&vcc->sk->wmem_alloc); ATM_SKB(skb)->atm_options = vcc->atm_options; entry->vccs->last_use = jiffies; DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev); old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */ if (old) { printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n"); return 0; } clip_priv->stats.tx_packets++; clip_priv->stats.tx_bytes += skb->len; (void) vcc->send(vcc,skb); if (atm_may_send(vcc,0)) { entry->vccs->xoff = 0; return 0; } spin_lock_irqsave(&clip_priv->xoff_lock,flags); netif_stop_queue(dev); /* XOFF -> throttle immediately */ barrier(); if (!entry->vccs->xoff) netif_start_queue(dev); /* Oh, we just raced with clip_pop. netif_start_queue should be good enough, because nothing should really be asleep because of the brief netif_stop_queue. If this isn't true or if it changes, use netif_wake_queue instead. */ spin_unlock_irqrestore(&clip_priv->xoff_lock,flags); return 0; } static struct net_device_stats *clip_get_stats(struct net_device *dev) { return &PRIV(dev)->stats; } static int clip_mkip(struct atm_vcc *vcc,int timeout) { struct clip_vcc *clip_vcc; struct sk_buff_head copy; struct sk_buff *skb; if (!vcc->push) return -EBADFD; clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL); if (!clip_vcc) return -ENOMEM; DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc); clip_vcc->vcc = vcc; vcc->user_back = clip_vcc; clip_vcc->entry = NULL; clip_vcc->xoff = 0; clip_vcc->encap = 1; clip_vcc->last_use = jiffies; clip_vcc->idle_timeout = timeout*HZ; clip_vcc->old_push = vcc->push; clip_vcc->old_pop = vcc->pop; vcc->push = clip_push; vcc->pop = clip_pop; skb_queue_head_init(©); skb_migrate(&vcc->sk->receive_queue,©); /* re-process everything received between connection setup and MKIP */ while ((skb = skb_dequeue(©))) if (!clip_devs) { atm_return(vcc,skb->truesize); kfree_skb(skb); } else { unsigned int len = skb->len; skb_get(skb); clip_push(vcc,skb); PRIV(skb->dev)->stats.rx_packets--; PRIV(skb->dev)->stats.rx_bytes -= len; kfree_skb(skb); } return 0; } static int clip_setentry(struct atm_vcc *vcc,u32 ip) { struct neighbour *neigh; struct atmarp_entry *entry; int error; struct clip_vcc *clip_vcc; struct rtable *rt; if (vcc->push != clip_push) { printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n"); return -EBADF; } clip_vcc = CLIP_VCC(vcc); if (!ip) { if (!clip_vcc->entry) { printk(KERN_ERR "hiding hidden ATMARP entry\n"); return 0; } DPRINTK("setentry: remove\n"); unlink_clip_vcc(clip_vcc); return 0; } error = ip_route_output(&rt,ip,0,1,0); if (error) return error; neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1); ip_rt_put(rt); if (!neigh) return -ENOMEM; entry = NEIGH2ENTRY(neigh); if (entry != clip_vcc->entry) { if (!clip_vcc->entry) DPRINTK("setentry: add\n"); else { DPRINTK("setentry: update\n"); unlink_clip_vcc(clip_vcc); } link_vcc(clip_vcc,entry); } error = neigh_update(neigh,llc_oui,NUD_PERMANENT,1,0); neigh_release(neigh); return error; } static int clip_init(struct net_device *dev) { DPRINTK("clip_init %s\n",dev->name); dev->hard_start_xmit = clip_start_xmit; /* sg_xmit ... */ dev->hard_header = NULL; dev->rebuild_header = NULL; dev->set_mac_address = NULL; dev->hard_header_parse = NULL; dev->hard_header_cache = NULL; dev->header_cache_update = NULL; dev->change_mtu = NULL; dev->do_ioctl = NULL; dev->get_stats = clip_get_stats; dev->type = ARPHRD_ATM; dev->hard_header_len = RFC1483LLC_LEN; dev->mtu = RFC1626_MTU; dev->addr_len = 0; dev->tx_queue_len = 100; /* "normal" queue (packets) */ /* When using a "real" qdisc, the qdisc determines the queue */ /* length. tx_queue_len is only used for the default case, */ /* without any more elaborate queuing. 100 is a reasonable */ /* compromise between decent burst-tolerance and protection */ /* against memory hogs. */ dev->flags = 0; return 0; } static int clip_create(int number) { struct net_device *dev; struct clip_priv *clip_priv; int error; if (number != -1) { for (dev = clip_devs; dev; dev = PRIV(dev)->next) if (PRIV(dev)->number == number) return -EEXIST; } else { number = 0; for (dev = clip_devs; dev; dev = PRIV(dev)->next) if (PRIV(dev)->number >= number) number = PRIV(dev)->number+1; } dev = kmalloc(sizeof(struct net_device)+sizeof(struct clip_priv), GFP_KERNEL); if (!dev) return -ENOMEM; memset(dev,0,sizeof(struct net_device)+sizeof(struct clip_priv)); clip_priv = PRIV(dev); sprintf(dev->name,"atm%d",number); dev->init = clip_init; spin_lock_init(&clip_priv->xoff_lock); clip_priv->number = number; error = register_netdev(dev); if (error) { kfree(dev); return error; } clip_priv->next = clip_devs; clip_devs = dev; DPRINTK("registered (net:%s)\n",dev->name); return number; } static int clip_device_event(struct notifier_block *this,unsigned long event, void *dev) { /* ignore non-CLIP devices */ if (((struct net_device *) dev)->type != ARPHRD_ATM || ((struct net_device *) dev)->init != clip_init) return NOTIFY_DONE; switch (event) { case NETDEV_UP: DPRINTK("clip_device_event NETDEV_UP\n"); (void) to_atmarpd(act_up,PRIV(dev)->number,0); break; case NETDEV_GOING_DOWN: DPRINTK("clip_device_event NETDEV_DOWN\n"); (void) to_atmarpd(act_down,PRIV(dev)->number,0); break; case NETDEV_CHANGE: case NETDEV_CHANGEMTU: DPRINTK("clip_device_event NETDEV_CHANGE*\n"); (void) to_atmarpd(act_change,PRIV(dev)->number,0); break; case NETDEV_REBOOT: case NETDEV_REGISTER: case NETDEV_DOWN: DPRINTK("clip_device_event %ld\n",event); /* ignore */ break; default: printk(KERN_WARNING "clip_device_event: unknown event " "%ld\n",event); break; } return NOTIFY_DONE; } static int clip_inet_event(struct notifier_block *this,unsigned long event, void *ifa) { struct in_device *in_dev; in_dev = ((struct in_ifaddr *) ifa)->ifa_dev; if (!in_dev || !in_dev->dev) { printk(KERN_WARNING "clip_inet_event: no device\n"); return NOTIFY_DONE; } /* * Transitions are of the down-change-up type, so it's sufficient to * handle the change on up. */ if (event != NETDEV_UP) return NOTIFY_DONE; return clip_device_event(this,NETDEV_CHANGE,in_dev->dev); } static struct notifier_block clip_dev_notifier = { clip_device_event, NULL, 0 }; static struct notifier_block clip_inet_notifier = { clip_inet_event, NULL, 0 }; static void atmarpd_close(struct atm_vcc *vcc) { DPRINTK("atmarpd_close\n"); atmarpd = NULL; /* assumed to be atomic */ barrier(); unregister_inetaddr_notifier(&clip_inet_notifier); unregister_netdevice_notifier(&clip_dev_notifier); if (skb_peek(&vcc->sk->receive_queue)) printk(KERN_ERR "atmarpd_close: closing with requests " "pending\n"); skb_queue_purge(&vcc->sk->receive_queue); DPRINTK("(done)\n"); MOD_DEC_USE_COUNT; } static struct atmdev_ops atmarpd_dev_ops = { .close = atmarpd_close, }; static struct atm_dev atmarpd_dev = { .ops = &atmarpd_dev_ops, .type = "arpd", .number = 999, .lock = SPIN_LOCK_UNLOCKED }; static int atm_init_atmarp(struct atm_vcc *vcc) { struct net_device *dev; if (atmarpd) return -EADDRINUSE; if (start_timer) { start_timer = 0; init_timer(&idle_timer); idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ; idle_timer.function = idle_timer_check; add_timer(&idle_timer); } atmarpd = vcc; set_bit(ATM_VF_META,&vcc->flags); set_bit(ATM_VF_READY,&vcc->flags); /* allow replies and avoid getting closed if signaling dies */ vcc->dev = &atmarpd_dev; vcc_insert_socket(vcc->sk); vcc->push = NULL; vcc->pop = NULL; /* crash */ vcc->push_oam = NULL; /* crash */ if (register_netdevice_notifier(&clip_dev_notifier)) printk(KERN_ERR "register_netdevice_notifier failed\n"); if (register_inetaddr_notifier(&clip_inet_notifier)) printk(KERN_ERR "register_inetaddr_notifier failed\n"); for (dev = clip_devs; dev; dev = PRIV(dev)->next) if (dev->flags & IFF_UP) (void) to_atmarpd(act_up,PRIV(dev)->number,0); MOD_INC_USE_COUNT; return 0; } static struct atm_clip_ops __atm_clip_ops = { .clip_create = clip_create, .clip_mkip = clip_mkip, .clip_setentry = clip_setentry, .clip_encap = clip_encap, .clip_push = clip_push, .atm_init_atmarp = atm_init_atmarp, .owner = THIS_MODULE }; static int __init atm_clip_init(void) { neigh_table_init(&clip_tbl); clip_tbl_hook = &clip_tbl; atm_clip_ops_set(&__atm_clip_ops); return 0; } static void __exit atm_clip_exit(void) { struct net_device *dev, *next; atm_clip_ops_set(NULL); /* First, stop the idle timer, so it stops banging * on the table. */ if (start_timer == 0) del_timer(&idle_timer); /* Next, purge the table, so that the device * unregister loop below does not hang due to * device references remaining in the table. */ neigh_ifdown(&clip_tbl, NULL); dev = clip_devs; while (dev) { next = PRIV(dev)->next; unregister_netdev(dev); kfree(dev); dev = next; } /* Now it is safe to fully shutdown whole table. */ neigh_table_clear(&clip_tbl); clip_tbl_hook = NULL; } module_init(atm_clip_init); module_exit(atm_clip_exit); MODULE_LICENSE("GPL");