addrconf.c

嵌入式系统设计与实验教材二源码linux内核移植与编译

				       ifp->prefix_len,
				       ifp->scope,
				       ifp->flags,
				       ifp->idev->dev->name);
			pos=begin+len;
			if(pos<offset) {
				len=0;
				begin=pos;
			}
			if(pos>offset+length) {
				read_unlock_bh(&addrconf_hash_lock);
				goto done;
			}
		}
		read_unlock_bh(&addrconf_hash_lock);
	}

done:

	*start=buffer+(offset-begin);
	len-=(offset-begin);
	if(len>length)
		len=length;
	if(len<0)
		len=0;
	return len;
}

#endif	/* CONFIG_PROC_FS */

/*
 *	Periodic address status verification
 */

void addrconf_verify(unsigned long foo)
{
	struct inet6_ifaddr *ifp;
	unsigned long now = jiffies;
	int i;

	for (i=0; i < IN6_ADDR_HSIZE; i++) {

restart:
		write_lock(&addrconf_hash_lock);
		for (ifp=inet6_addr_lst[i]; ifp; ifp=ifp->lst_next) {
			unsigned long age;

			if (ifp->flags & IFA_F_PERMANENT)
				continue;

			age = (now - ifp->tstamp) / HZ;

			if (age > ifp->valid_lft) {
				in6_ifa_hold(ifp);
				write_unlock(&addrconf_hash_lock);
				ipv6_del_addr(ifp);
				goto restart;
			} else if (age > ifp->prefered_lft) {
				int deprecate = 0;

				spin_lock(&ifp->lock);
				if (!(ifp->flags&IFA_F_DEPRECATED)) {
					deprecate = 1;
					ifp->flags |= IFA_F_DEPRECATED;
				}
				spin_unlock(&ifp->lock);

				if (deprecate) {
					in6_ifa_hold(ifp);
					write_unlock(&addrconf_hash_lock);

					ipv6_ifa_notify(0, ifp);
					in6_ifa_put(ifp);
					goto restart;
				}
			}
		}
		write_unlock(&addrconf_hash_lock);
	}

	mod_timer(&addr_chk_timer, jiffies + ADDR_CHECK_FREQUENCY);
}

static int
inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct ifaddrmsg *ifm = NLMSG_DATA(nlh);
	struct in6_addr *pfx;

	pfx = NULL;
	if (rta[IFA_ADDRESS-1]) {
		if (RTA_PAYLOAD(rta[IFA_ADDRESS-1]) < sizeof(*pfx))
			return -EINVAL;
		pfx = RTA_DATA(rta[IFA_ADDRESS-1]);
	}
	if (rta[IFA_LOCAL-1]) {
		if (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx)))
			return -EINVAL;
		pfx = RTA_DATA(rta[IFA_LOCAL-1]);
	}
	if (pfx == NULL)
		return -EINVAL;

	return inet6_addr_del(ifm->ifa_index, pfx, ifm->ifa_prefixlen);
}

static int
inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr  **rta = arg;
	struct ifaddrmsg *ifm = NLMSG_DATA(nlh);
	struct in6_addr *pfx;

	pfx = NULL;
	if (rta[IFA_ADDRESS-1]) {
		if (RTA_PAYLOAD(rta[IFA_ADDRESS-1]) < sizeof(*pfx))
			return -EINVAL;
		pfx = RTA_DATA(rta[IFA_ADDRESS-1]);
	}
	if (rta[IFA_LOCAL-1]) {
		if (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx)))
			return -EINVAL;
		pfx = RTA_DATA(rta[IFA_LOCAL-1]);
	}
	if (pfx == NULL)
		return -EINVAL;

	return inet6_addr_add(ifm->ifa_index, pfx, ifm->ifa_prefixlen);
}

static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
			     u32 pid, u32 seq, int event)
{
	struct ifaddrmsg *ifm;
	struct nlmsghdr  *nlh;
	struct ifa_cacheinfo ci;
	unsigned char	 *b = skb->tail;

	nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*ifm));
	ifm = NLMSG_DATA(nlh);
	ifm->ifa_family = AF_INET6;
	ifm->ifa_prefixlen = ifa->prefix_len;
	ifm->ifa_flags = ifa->flags;
	ifm->ifa_scope = RT_SCOPE_UNIVERSE;
	if (ifa->scope&IFA_HOST)
		ifm->ifa_scope = RT_SCOPE_HOST;
	else if (ifa->scope&IFA_LINK)
		ifm->ifa_scope = RT_SCOPE_LINK;
	else if (ifa->scope&IFA_SITE)
		ifm->ifa_scope = RT_SCOPE_SITE;
	ifm->ifa_index = ifa->idev->dev->ifindex;
	RTA_PUT(skb, IFA_ADDRESS, 16, &ifa->addr);
	if (!(ifa->flags&IFA_F_PERMANENT)) {
		ci.ifa_prefered = ifa->prefered_lft;
		ci.ifa_valid = ifa->valid_lft;
		if (ci.ifa_prefered != 0xFFFFFFFF) {
			long tval = (jiffies - ifa->tstamp)/HZ;
			ci.ifa_prefered -= tval;
			if (ci.ifa_valid != 0xFFFFFFFF)
				ci.ifa_valid -= tval;
		}
		RTA_PUT(skb, IFA_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 inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx, ip_idx;
	int s_idx, s_ip_idx;
 	struct inet6_ifaddr *ifa;

	s_idx = cb->args[0];
	s_ip_idx = ip_idx = cb->args[1];

	for (idx=0; idx < IN6_ADDR_HSIZE; idx++) {
		if (idx < s_idx)
			continue;
		if (idx > s_idx)
			s_ip_idx = 0;
		read_lock_bh(&addrconf_hash_lock);
		for (ifa=inet6_addr_lst[idx], ip_idx = 0; ifa;
		     ifa = ifa->lst_next, ip_idx++) {
			if (ip_idx < s_ip_idx)
				continue;
			if (inet6_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
					      cb->nlh->nlmsg_seq, RTM_NEWADDR) <= 0) {
				read_unlock_bh(&addrconf_hash_lock);
				goto done;
			}
		}
		read_unlock_bh(&addrconf_hash_lock);
	}
done:
	cb->args[0] = idx;
	cb->args[1] = ip_idx;

	return skb->len;
}

static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
{
	struct sk_buff *skb;
	int size = NLMSG_SPACE(sizeof(struct ifaddrmsg)+128);

	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb) {
		netlink_set_err(rtnl, 0, RTMGRP_IPV6_IFADDR, ENOBUFS);
		return;
	}
	if (inet6_fill_ifaddr(skb, ifa, 0, 0, event) < 0) {
		kfree_skb(skb);
		netlink_set_err(rtnl, 0, RTMGRP_IPV6_IFADDR, EINVAL);
		return;
	}
	NETLINK_CB(skb).dst_groups = RTMGRP_IPV6_IFADDR;
	netlink_broadcast(rtnl, skb, 0, RTMGRP_IPV6_IFADDR, GFP_ATOMIC);
}

static struct rtnetlink_link inet6_rtnetlink_table[RTM_MAX-RTM_BASE+1] =
{
	{ NULL,			NULL,			},
	{ NULL,			NULL,			},
	{ NULL,			NULL,			},
	{ NULL,			NULL,			},

	{ inet6_rtm_newaddr,	NULL,			},
	{ inet6_rtm_deladdr,	NULL,			},
	{ NULL,			inet6_dump_ifaddr,	},
	{ NULL,			NULL,			},

	{ inet6_rtm_newroute,	NULL,			},
	{ inet6_rtm_delroute,	NULL,			},
	{ inet6_rtm_getroute,	inet6_dump_fib,		},
	{ NULL,			NULL,			},
};

static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
{
	inet6_ifa_notify(event ? : RTM_NEWADDR, ifp);

	switch (event) {
	case RTM_NEWADDR:
		ip6_rt_addr_add(&ifp->addr, ifp->idev->dev);
		break;
	case RTM_DELADDR:
		addrconf_leave_solict(ifp->idev->dev, &ifp->addr);
		if (!ipv6_chk_addr(&ifp->addr, ifp->idev->dev))
			ip6_rt_addr_del(&ifp->addr, ifp->idev->dev);
		break;
	}
}

#ifdef CONFIG_SYSCTL

static
int addrconf_sysctl_forward(ctl_table *ctl, int write, struct file * filp,
			   void *buffer, size_t *lenp)
{
	int *valp = ctl->data;
	int val = *valp;
	int ret;

	ret = proc_dointvec(ctl, write, filp, buffer, lenp);

	if (write && *valp != val && valp != &ipv6_devconf_dflt.forwarding) {
		struct inet6_dev *idev = NULL;

		if (valp != &ipv6_devconf.forwarding) {
			struct net_device *dev = dev_get_by_index(ctl->ctl_name);
			if (dev) {
				idev = in6_dev_get(dev);
				dev_put(dev);
			}
			if (idev == NULL)
				return ret;
		} else
			ipv6_devconf_dflt.forwarding = ipv6_devconf.forwarding;

		addrconf_forward_change(idev);

		if (*valp)
			rt6_purge_dflt_routers(0);
		if (idev)
			in6_dev_put(idev);
	}

        return ret;
}

static struct addrconf_sysctl_table
{
	struct ctl_table_header *sysctl_header;
	ctl_table addrconf_vars[11];
	ctl_table addrconf_dev[2];
	ctl_table addrconf_conf_dir[2];
	ctl_table addrconf_proto_dir[2];
	ctl_table addrconf_root_dir[2];
} addrconf_sysctl = {
	NULL,
        {{NET_IPV6_FORWARDING, "forwarding",
         &ipv6_devconf.forwarding, sizeof(int), 0644, NULL,
         &addrconf_sysctl_forward},

	{NET_IPV6_HOP_LIMIT, "hop_limit",
         &ipv6_devconf.hop_limit, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_MTU, "mtu",
         &ipv6_devconf.mtu6, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_ACCEPT_RA, "accept_ra",
         &ipv6_devconf.accept_ra, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_ACCEPT_REDIRECTS, "accept_redirects",
         &ipv6_devconf.accept_redirects, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_AUTOCONF, "autoconf",
         &ipv6_devconf.autoconf, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_DAD_TRANSMITS, "dad_transmits",
         &ipv6_devconf.dad_transmits, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_RTR_SOLICITS, "router_solicitations",
         &ipv6_devconf.rtr_solicits, sizeof(int), 0644, NULL,
         &proc_dointvec},

	{NET_IPV6_RTR_SOLICIT_INTERVAL, "router_solicitation_interval",
         &ipv6_devconf.rtr_solicit_interval, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},

	{NET_IPV6_RTR_SOLICIT_DELAY, "router_solicitation_delay",
         &ipv6_devconf.rtr_solicit_delay, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},

	{0}},

	{{NET_PROTO_CONF_ALL, "all", NULL, 0, 0555, addrconf_sysctl.addrconf_vars},{0}},
	{{NET_IPV6_CONF, "conf", NULL, 0, 0555, addrconf_sysctl.addrconf_dev},{0}},
	{{NET_IPV6, "ipv6", NULL, 0, 0555, addrconf_sysctl.addrconf_conf_dir},{0}},
	{{CTL_NET, "net", NULL, 0, 0555, addrconf_sysctl.addrconf_proto_dir},{0}}
};

static void addrconf_sysctl_register(struct inet6_dev *idev, struct ipv6_devconf *p)
{
	int i;
	struct net_device *dev = idev ? idev->dev : NULL;
	struct addrconf_sysctl_table *t;

	t = kmalloc(sizeof(*t), GFP_KERNEL);
	if (t == NULL)
		return;
	memcpy(t, &addrconf_sysctl, sizeof(*t));
	for (i=0; i<sizeof(t->addrconf_vars)/sizeof(t->addrconf_vars[0])-1; i++) {
		t->addrconf_vars[i].data += (char*)p - (char*)&ipv6_devconf;
		t->addrconf_vars[i].de = NULL;
	}
	if (dev) {
		t->addrconf_dev[0].procname = dev->name;
		t->addrconf_dev[0].ctl_name = dev->ifindex;
	} else {
		t->addrconf_dev[0].procname = "default";
		t->addrconf_dev[0].ctl_name = NET_PROTO_CONF_DEFAULT;
	}
	t->addrconf_dev[0].child = t->addrconf_vars;
	t->addrconf_dev[0].de = NULL;
	t->addrconf_conf_dir[0].child = t->addrconf_dev;
	t->addrconf_conf_dir[0].de = NULL;
	t->addrconf_proto_dir[0].child = t->addrconf_conf_dir;
	t->addrconf_proto_dir[0].de = NULL;
	t->addrconf_root_dir[0].child = t->addrconf_proto_dir;
	t->addrconf_root_dir[0].de = NULL;

	t->sysctl_header = register_sysctl_table(t->addrconf_root_dir, 0);
	if (t->sysctl_header == NULL)
		kfree(t);
	else
		p->sysctl = t;
}

static void addrconf_sysctl_unregister(struct ipv6_devconf *p)
{
	if (p->sysctl) {
		struct addrconf_sysctl_table *t = p->sysctl;
		p->sysctl = NULL;
		unregister_sysctl_table(t->sysctl_header);
		kfree(t);
	}
}


#endif

/*
 *      Device notifier
 */

int register_inet6addr_notifier(struct notifier_block *nb)
{
        return notifier_chain_register(&inet6addr_chain, nb);
}

int unregister_inet6addr_notifier(struct notifier_block *nb)
{
        return notifier_chain_unregister(&inet6addr_chain,nb);
}

/*
 *	Init / cleanup code
 */

void __init addrconf_init(void)
{
#ifdef MODULE
	struct net_device *dev;

	/* This takes sense only during module load. */
	rtnl_lock();
	for (dev = dev_base; dev; dev = dev->next) {
		if (!(dev->flags&IFF_UP))
			continue;

		switch (dev->type) {
		case ARPHRD_LOOPBACK:	
			init_loopback(dev);
			break;
		case ARPHRD_ETHER:
		case ARPHRD_FDDI:
		case ARPHRD_IEEE802_TR:	
			addrconf_dev_config(dev);
			break;
		default:;
			/* Ignore all other */
		}
	}
	rtnl_unlock();
#endif

#ifdef CONFIG_PROC_FS
	proc_net_create("if_inet6", 0, iface_proc_info);
#endif
	
	addr_chk_timer.expires = jiffies + ADDR_CHECK_FREQUENCY;
	add_timer(&addr_chk_timer);
	rtnetlink_links[PF_INET6] = inet6_rtnetlink_table;
#ifdef CONFIG_SYSCTL
	addrconf_sysctl.sysctl_header =
		register_sysctl_table(addrconf_sysctl.addrconf_root_dir, 0);
	addrconf_sysctl_register(NULL, &ipv6_devconf_dflt);
#endif
}

#ifdef MODULE
void addrconf_cleanup(void)
{
 	struct net_device *dev;
 	struct inet6_dev *idev;
 	struct inet6_ifaddr *ifa;
	int i;

	rtnetlink_links[PF_INET6] = NULL;
#ifdef CONFIG_SYSCTL
	addrconf_sysctl_unregister(&ipv6_devconf_dflt);
	addrconf_sysctl_unregister(&ipv6_devconf);
#endif

	rtnl_lock();

	/*
	 *	clean dev list.
	 */

	for (dev=dev_base; dev; dev=dev->next) {
		if ((idev = __in6_dev_get(dev)) == NULL)
			continue;
		addrconf_ifdown(dev, 1);
	}

	/*
	 *	Check hash table.
	 */

	write_lock_bh(&addrconf_hash_lock);
	for (i=0; i < IN6_ADDR_HSIZE; i++) {
		for (ifa=inet6_addr_lst[i]; ifa; ) {
			struct inet6_ifaddr *bifa;

			bifa = ifa;
			ifa = ifa->lst_next;
			printk(KERN_DEBUG "bug: IPv6 address leakage detected: ifa=%p\n", bifa);
			/* Do not free it; something is wrong.
			   Now we can investigate it with debugger.
			 */
		}
	}
	write_unlock_bh(&addrconf_hash_lock);

	del_timer(&addr_chk_timer);

	rtnl_unlock();

#ifdef CONFIG_PROC_FS
	proc_net_remove("if_inet6");
#endif
}
#endif	/* MODULE */