patch-2.4.21 linux-2.4.21/net/ipv6/anycast.c

• Lines: 490
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/net/ipv6/anycast.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/net/ipv6/anycast.c linux-2.4.21/net/ipv6/anycast.c
@@ -0,0 +1,489 @@
+/*
+ *	Anycast support for IPv6
+ *	Linux INET6 implementation 
+ *
+ *	Authors:
+ *	David L Stevens (dlstevens@us.ibm.com)
+ *
+ *	based heavily on net/ipv6/mcast.c
+ *
+ *	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.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/random.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/sched.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/route.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/if_inet6.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+#include <net/ip6_route.h>
+
+#include <net/checksum.h>
+
+/* Big ac list lock for all the sockets */
+static rwlock_t ipv6_sk_ac_lock = RW_LOCK_UNLOCKED;
+
+/* XXX ip6_addr_match() and ip6_onlink() really belong in net/core.c */
+
+static int
+ip6_addr_match(struct in6_addr *addr1, struct in6_addr *addr2, int prefix)
+{
+	__u32	mask;
+	int	i;
+
+	if (prefix > 128 || prefix < 0)
+		return 0;
+	if (prefix == 0)
+		return 1;
+	for (i=0; i<4; ++i) {
+		if (prefix >= 32)
+			mask = ~0;
+		else
+			mask = htonl(~0 << (32 - prefix));
+		if ((addr1->s6_addr32[i] ^ addr2->s6_addr32[i]) & mask)
+			return 0;
+		prefix -= 32;
+		if (prefix <= 0)
+			break;
+	}
+	return 1;
+}
+
+static int
+ip6_onlink(struct in6_addr *addr, struct net_device *dev)
+{
+	struct inet6_dev	*idev;
+	struct inet6_ifaddr	*ifa;
+	int	onlink;
+
+	onlink = 0;
+	read_lock(&addrconf_lock);
+	idev = __in6_dev_get(dev);
+	if (idev) {
+		read_lock_bh(&idev->lock);
+		for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
+			onlink = ip6_addr_match(addr, &ifa->addr,
+					ifa->prefix_len);
+			if (onlink)
+				break;
+		}
+		read_unlock_bh(&idev->lock);
+	}
+	read_unlock(&addrconf_lock);
+	return onlink;
+}
+
+
+/*
+ *	socket join an anycast group
+ */
+
+int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
+{
+	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
+	struct net_device *dev = NULL;
+	struct inet6_dev *idev;
+	struct ipv6_ac_socklist *pac;
+	int	ishost = !ipv6_devconf.forwarding;
+	int	err = 0;
+
+	if (ipv6_addr_type(addr) & IPV6_ADDR_MULTICAST)
+		return -EINVAL;
+
+	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
+	if (pac == NULL)
+		return -ENOMEM;
+	pac->acl_next = NULL;
+	ipv6_addr_copy(&pac->acl_addr, addr);
+
+	if (ifindex == 0) {
+		struct rt6_info *rt;
+
+		rt = rt6_lookup(addr, NULL, 0, 0);
+		if (rt) {
+			dev = rt->rt6i_dev;
+			dev_hold(dev);
+			dst_release(&rt->u.dst);
+		} else if (ishost) {
+			sock_kfree_s(sk, pac, sizeof(*pac));
+			return -EADDRNOTAVAIL;
+		} else {
+			/* router, no matching interface: just pick one */
+
+			dev = dev_get_by_flags(IFF_UP, IFF_UP|IFF_LOOPBACK);
+		}
+	} else
+		dev = dev_get_by_index(ifindex);
+
+	if (dev == NULL) {
+		sock_kfree_s(sk, pac, sizeof(*pac));
+		return -ENODEV;
+	}
+
+	idev = in6_dev_get(dev);
+	if (!idev) {
+		sock_kfree_s(sk, pac, sizeof(*pac));
+		dev_put(dev);
+		if (ifindex)
+			return -ENODEV;
+		else
+			return -EADDRNOTAVAIL;
+	}
+	/* reset ishost, now that we have a specific device */
+	ishost = !idev->cnf.forwarding;
+	in6_dev_put(idev);
+
+	pac->acl_ifindex = dev->ifindex;
+
+	/* XXX
+	 * For hosts, allow link-local or matching prefix anycasts.
+	 * This obviates the need for propagating anycast routes while
+	 * still allowing some non-router anycast participation.
+	 *
+	 * allow anyone to join anycasts that don't require a special route
+	 * and can't be spoofs of unicast addresses (reserved anycast only)
+	 */
+	if (!ip6_onlink(addr, dev)) {
+		if (ishost)
+			err = -EADDRNOTAVAIL;
+		else if (!capable(CAP_NET_ADMIN))
+			err = -EPERM;
+		if (err) {
+			sock_kfree_s(sk, pac, sizeof(*pac));
+			dev_put(dev);
+			return err;
+		}
+	} else if (!(ipv6_addr_type(addr) & IPV6_ADDR_ANYCAST) &&
+		   !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	err = ipv6_dev_ac_inc(dev, addr);
+	if (err) {
+		sock_kfree_s(sk, pac, sizeof(*pac));
+		dev_put(dev);
+		return err;
+	}
+
+	write_lock_bh(&ipv6_sk_ac_lock);
+	pac->acl_next = np->ipv6_ac_list;
+	np->ipv6_ac_list = pac;
+	write_unlock_bh(&ipv6_sk_ac_lock);
+
+	dev_put(dev);
+
+	return 0;
+}
+
+/*
+ *	socket leave an anycast group
+ */
+int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
+{
+	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
+	struct net_device *dev;
+	struct ipv6_ac_socklist *pac, *prev_pac;
+
+	write_lock_bh(&ipv6_sk_ac_lock);
+	prev_pac = 0;
+	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
+		if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
+		     ipv6_addr_cmp(&pac->acl_addr, addr) == 0)
+			break;
+		prev_pac = pac;
+	}
+	if (!pac) {
+		write_unlock_bh(&ipv6_sk_ac_lock);
+		return -ENOENT;
+	}
+	if (prev_pac)
+		prev_pac->acl_next = pac->acl_next;
+	else
+		np->ipv6_ac_list = pac->acl_next;
+
+	write_unlock_bh(&ipv6_sk_ac_lock);
+
+	dev = dev_get_by_index(pac->acl_ifindex);
+	if (dev) {
+		ipv6_dev_ac_dec(dev, &pac->acl_addr);
+		dev_put(dev);
+	}
+	sock_kfree_s(sk, pac, sizeof(*pac));
+	return 0;
+}
+
+void ipv6_sock_ac_close(struct sock *sk)
+{
+	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
+	struct net_device *dev = 0;
+	struct ipv6_ac_socklist *pac;
+	int	prev_index;
+
+	write_lock_bh(&ipv6_sk_ac_lock);
+	pac = np->ipv6_ac_list;
+	np->ipv6_ac_list = 0;
+	write_unlock_bh(&ipv6_sk_ac_lock);
+
+	prev_index = 0;
+	while (pac) {
+		struct ipv6_ac_socklist *next = pac->acl_next;
+
+		if (pac->acl_ifindex != prev_index) {
+			if (dev)
+				dev_put(dev);
+			dev = dev_get_by_index(pac->acl_ifindex);
+			prev_index = pac->acl_ifindex;
+		}
+		if (dev)
+			ipv6_dev_ac_dec(dev, &pac->acl_addr);
+		sock_kfree_s(sk, pac, sizeof(*pac));
+		pac = next;
+	}
+	if (dev)
+		dev_put(dev);
+}
+
+int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
+{
+	struct ipv6_ac_socklist *pac;
+	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
+	int	found;
+
+	found = 0;
+	read_lock(&ipv6_sk_ac_lock);
+	for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
+		if (ifindex && pac->acl_ifindex != ifindex)
+			continue;
+		found = ipv6_addr_cmp(&pac->acl_addr, addr) == 0;
+		if (found)
+			break;
+	}
+	read_unlock(&ipv6_sk_ac_lock);
+
+	return found;
+}
+
+static void aca_put(struct ifacaddr6 *ac)
+{
+	if (atomic_dec_and_test(&ac->aca_refcnt)) {
+		in6_dev_put(ac->aca_idev);
+		kfree(ac);
+	}
+}
+
+/*
+ *	device anycast group inc (add if not found)
+ */
+int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
+{
+	struct ifacaddr6 *aca;
+	struct inet6_dev *idev;
+
+	idev = in6_dev_get(dev);
+
+	if (idev == NULL)
+		return -EINVAL;
+
+	write_lock_bh(&idev->lock);
+	if (idev->dead) {
+		write_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+		return -ENODEV;
+	}
+
+	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
+		if (ipv6_addr_cmp(&aca->aca_addr, addr) == 0) {
+			aca->aca_users++;
+			write_unlock_bh(&idev->lock);
+			in6_dev_put(idev);
+			return 0;
+		}
+	}
+
+	/*
+	 *	not found: create a new one.
+	 */
+
+	aca = kmalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
+
+	if (aca == NULL) {
+		write_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+		return -ENOMEM;
+	}
+
+	memset(aca, 0, sizeof(struct ifacaddr6));
+
+	ipv6_addr_copy(&aca->aca_addr, addr);
+	aca->aca_idev = idev;
+	aca->aca_users = 1;
+	atomic_set(&aca->aca_refcnt, 2);
+	aca->aca_lock = SPIN_LOCK_UNLOCKED;
+
+	aca->aca_next = idev->ac_list;
+	idev->ac_list = aca;
+	write_unlock_bh(&idev->lock);
+
+	ip6_rt_addr_add(&aca->aca_addr, dev);
+
+	addrconf_join_solict(dev, &aca->aca_addr);
+
+	aca_put(aca);
+	return 0;
+}
+
+/*
+ *	device anycast group decrement
+ */
+int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
+{
+	struct inet6_dev *idev;
+	struct ifacaddr6 *aca, *prev_aca;
+
+	idev = in6_dev_get(dev);
+	if (idev == NULL)
+		return -ENODEV;
+
+	write_lock_bh(&idev->lock);
+	prev_aca = 0;
+	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
+		if (ipv6_addr_cmp(&aca->aca_addr, addr) == 0)
+			break;
+		prev_aca = aca;
+	}
+	if (!aca) {
+		write_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+		return -ENOENT;
+	}
+	if (--aca->aca_users > 0) {
+		write_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+		return 0;
+	}
+	if (prev_aca)
+		prev_aca->aca_next = aca->aca_next;
+	else
+		idev->ac_list = aca->aca_next;
+	write_unlock_bh(&idev->lock);
+	addrconf_leave_solict(dev, &aca->aca_addr);
+
+	ip6_rt_addr_del(&aca->aca_addr, dev);
+
+	aca_put(aca);
+	in6_dev_put(idev);
+	return 0;
+}
+
+/*
+ *	check if the interface has this anycast address
+ */
+static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
+{
+	struct inet6_dev *idev;
+	struct ifacaddr6 *aca;
+
+	idev = in6_dev_get(dev);
+	if (idev) {
+		read_lock_bh(&idev->lock);
+		for (aca = idev->ac_list; aca; aca = aca->aca_next)
+			if (ipv6_addr_cmp(&aca->aca_addr, addr) == 0)
+				break;
+		read_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+		return aca != 0;
+	}
+	return 0;
+}
+
+/*
+ *	check if given interface (or any, if dev==0) has this anycast address
+ */
+int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
+{
+	if (dev)
+		return ipv6_chk_acast_dev(dev, addr);
+	read_lock(&dev_base_lock);
+	for (dev=dev_base; dev; dev=dev->next)
+		if (ipv6_chk_acast_dev(dev, addr))
+			break;
+	read_unlock(&dev_base_lock);
+	return dev != 0;
+}
+
+
+#ifdef CONFIG_PROC_FS
+int anycast6_get_info(char *buffer, char **start, off_t offset, int length)
+{
+	off_t pos=0, begin=0;
+	struct ifacaddr6 *im;
+	int len=0;
+	struct net_device *dev;
+	
+	read_lock(&dev_base_lock);
+	for (dev = dev_base; dev; dev = dev->next) {
+		struct inet6_dev *idev;
+
+		if ((idev = in6_dev_get(dev)) == NULL)
+			continue;
+
+		read_lock_bh(&idev->lock);
+		for (im = idev->ac_list; im; im = im->aca_next) {
+			int i;
+
+			len += sprintf(buffer+len,"%-4d %-15s ", dev->ifindex, dev->name);
+
+			for (i=0; i<16; i++)
+				len += sprintf(buffer+len, "%02x", im->aca_addr.s6_addr[i]);
+
+			len += sprintf(buffer+len, " %5d\n", im->aca_users);
+
+			pos=begin+len;
+			if (pos < offset) {
+				len=0;
+				begin=pos;
+			}
+			if (pos > offset+length) {
+				read_unlock_bh(&idev->lock);
+				in6_dev_put(idev);
+				goto done;
+			}
+		}
+		read_unlock_bh(&idev->lock);
+		in6_dev_put(idev);
+	}
+
+done:
+	read_unlock(&dev_base_lock);
+
+	*start=buffer+(offset-begin);
+	len-=(offset-begin);
+	if(len>length)
+		len=length;
+	if (len<0)
+		len=0;
+	return len;
+}
+
+#endif