path: root/net/atm/clip.c

/* net/atm/clip.c - RFC1577 Classical IP over ATM */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kernel.h> /* for UINT_MAX */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/timer.h>
#include <linux/if_arp.h> /* for some manifest constants */
#include <linux/notifier.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/atmclip.h>
#include <linux/atmarp.h>
#include <linux/capability.h>
#include <linux/ip.h> /* for net/route.h */
#include <linux/in.h> /* for struct sockaddr_in */
#include <linux/if.h> /* for IFF_UP */
#include <linux/inetdevice.h>
#include <linux/bitops.h>
#include <linux/poison.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <net/route.h> /* for struct rtable and routing */
#include <net/icmp.h> /* icmp_send */
#include <asm/param.h> /* for HZ */
#include <asm/byteorder.h> /* for htons etc. */
#include <asm/system.h> /* save/restore_flags */
#include <asm/uaccess.h>
#include <asm/atomic.h>

#include "common.h"
#include "resources.h"
#include <net/atmclip.h>

static struct net_device *clip_devs;
static struct atm_vcc *atmarpd;
static struct neigh_table clip_tbl;
static struct timer_list idle_timer;

static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
{
	struct sock *sk;
	struct atmarp_ctrl *ctrl;
	struct sk_buff *skb;

	pr_debug("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);

	sk = sk_atm(atmarpd);
	skb_queue_tail(&sk->sk_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);
	return 0;
}

static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
{
	pr_debug("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;
	}
	netif_tx_lock_bh(entry->neigh->dev);	/* 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,
					     NEIGH_UPDATE_F_ADMIN);
			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:
	netif_tx_unlock_bh(entry->neigh->dev);
}

/* 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->i