591 lines
12 KiB
C
591 lines
12 KiB
C
/*
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* Anycast support for IPv6
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* Linux INET6 implementation
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*
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* Authors:
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* David L Stevens (dlstevens@us.ibm.com)
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*
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* based heavily on net/ipv6/mcast.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/capability.h>
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/random.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/sched.h>
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#include <linux/net.h>
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#include <linux/in6.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/route.h>
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#include <linux/init.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <net/if_inet6.h>
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#include <net/ndisc.h>
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#include <net/addrconf.h>
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#include <net/ip6_route.h>
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#include <net/checksum.h>
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static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
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/* Big ac list lock for all the sockets */
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static DEFINE_RWLOCK(ipv6_sk_ac_lock);
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static int
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ip6_onlink(struct in6_addr *addr, struct net_device *dev)
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{
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struct inet6_dev *idev;
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struct inet6_ifaddr *ifa;
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int onlink;
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onlink = 0;
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read_lock(&addrconf_lock);
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idev = __in6_dev_get(dev);
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if (idev) {
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read_lock_bh(&idev->lock);
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for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
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onlink = ipv6_prefix_equal(addr, &ifa->addr,
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ifa->prefix_len);
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if (onlink)
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break;
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}
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read_unlock_bh(&idev->lock);
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}
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read_unlock(&addrconf_lock);
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return onlink;
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}
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/*
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* socket join an anycast group
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*/
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int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
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{
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struct ipv6_pinfo *np = inet6_sk(sk);
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struct net_device *dev = NULL;
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struct inet6_dev *idev;
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struct ipv6_ac_socklist *pac;
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int ishost = !ipv6_devconf.forwarding;
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int err = 0;
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if (!capable(CAP_NET_ADMIN))
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return -EPERM;
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if (ipv6_addr_is_multicast(addr))
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return -EINVAL;
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if (ipv6_chk_addr(addr, NULL, 0))
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return -EINVAL;
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pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
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if (pac == NULL)
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return -ENOMEM;
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pac->acl_next = NULL;
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ipv6_addr_copy(&pac->acl_addr, addr);
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if (ifindex == 0) {
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struct rt6_info *rt;
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rt = rt6_lookup(addr, NULL, 0, 0);
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if (rt) {
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dev = rt->rt6i_dev;
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dev_hold(dev);
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dst_release(&rt->u.dst);
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} else if (ishost) {
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err = -EADDRNOTAVAIL;
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goto out_free_pac;
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} else {
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/* router, no matching interface: just pick one */
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dev = dev_get_by_flags(IFF_UP, IFF_UP|IFF_LOOPBACK);
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}
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} else
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dev = dev_get_by_index(ifindex);
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if (dev == NULL) {
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err = -ENODEV;
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goto out_free_pac;
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}
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idev = in6_dev_get(dev);
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if (!idev) {
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if (ifindex)
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err = -ENODEV;
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else
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err = -EADDRNOTAVAIL;
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goto out_dev_put;
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}
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/* reset ishost, now that we have a specific device */
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ishost = !idev->cnf.forwarding;
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in6_dev_put(idev);
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pac->acl_ifindex = dev->ifindex;
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/* XXX
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* For hosts, allow link-local or matching prefix anycasts.
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* This obviates the need for propagating anycast routes while
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* still allowing some non-router anycast participation.
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*/
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if (!ip6_onlink(addr, dev)) {
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if (ishost)
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err = -EADDRNOTAVAIL;
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if (err)
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goto out_dev_put;
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}
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err = ipv6_dev_ac_inc(dev, addr);
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if (err)
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goto out_dev_put;
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write_lock_bh(&ipv6_sk_ac_lock);
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pac->acl_next = np->ipv6_ac_list;
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np->ipv6_ac_list = pac;
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write_unlock_bh(&ipv6_sk_ac_lock);
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dev_put(dev);
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return 0;
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out_dev_put:
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dev_put(dev);
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out_free_pac:
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sock_kfree_s(sk, pac, sizeof(*pac));
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return err;
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}
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/*
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* socket leave an anycast group
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*/
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int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
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{
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struct ipv6_pinfo *np = inet6_sk(sk);
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struct net_device *dev;
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struct ipv6_ac_socklist *pac, *prev_pac;
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write_lock_bh(&ipv6_sk_ac_lock);
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prev_pac = NULL;
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for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
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if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
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ipv6_addr_equal(&pac->acl_addr, addr))
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break;
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prev_pac = pac;
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}
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if (!pac) {
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write_unlock_bh(&ipv6_sk_ac_lock);
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return -ENOENT;
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}
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if (prev_pac)
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prev_pac->acl_next = pac->acl_next;
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else
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np->ipv6_ac_list = pac->acl_next;
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write_unlock_bh(&ipv6_sk_ac_lock);
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dev = dev_get_by_index(pac->acl_ifindex);
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if (dev) {
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ipv6_dev_ac_dec(dev, &pac->acl_addr);
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dev_put(dev);
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}
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sock_kfree_s(sk, pac, sizeof(*pac));
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return 0;
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}
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void ipv6_sock_ac_close(struct sock *sk)
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{
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struct ipv6_pinfo *np = inet6_sk(sk);
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struct net_device *dev = NULL;
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struct ipv6_ac_socklist *pac;
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int prev_index;
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write_lock_bh(&ipv6_sk_ac_lock);
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pac = np->ipv6_ac_list;
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np->ipv6_ac_list = NULL;
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write_unlock_bh(&ipv6_sk_ac_lock);
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prev_index = 0;
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while (pac) {
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struct ipv6_ac_socklist *next = pac->acl_next;
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if (pac->acl_ifindex != prev_index) {
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if (dev)
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dev_put(dev);
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dev = dev_get_by_index(pac->acl_ifindex);
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prev_index = pac->acl_ifindex;
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}
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if (dev)
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ipv6_dev_ac_dec(dev, &pac->acl_addr);
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sock_kfree_s(sk, pac, sizeof(*pac));
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pac = next;
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}
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if (dev)
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dev_put(dev);
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}
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#if 0
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/* The function is not used, which is funny. Apparently, author
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* supposed to use it to filter out datagrams inside udp/raw but forgot.
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*
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* It is OK, anycasts are not special comparing to delivery to unicasts.
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*/
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int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
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{
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struct ipv6_ac_socklist *pac;
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struct ipv6_pinfo *np = inet6_sk(sk);
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int found;
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found = 0;
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read_lock(&ipv6_sk_ac_lock);
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for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
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if (ifindex && pac->acl_ifindex != ifindex)
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continue;
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found = ipv6_addr_equal(&pac->acl_addr, addr);
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if (found)
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break;
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}
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read_unlock(&ipv6_sk_ac_lock);
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return found;
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}
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#endif
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static void aca_put(struct ifacaddr6 *ac)
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{
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if (atomic_dec_and_test(&ac->aca_refcnt)) {
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in6_dev_put(ac->aca_idev);
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dst_release(&ac->aca_rt->u.dst);
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kfree(ac);
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}
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}
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/*
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* device anycast group inc (add if not found)
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*/
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int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
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{
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struct ifacaddr6 *aca;
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struct inet6_dev *idev;
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struct rt6_info *rt;
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int err;
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idev = in6_dev_get(dev);
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if (idev == NULL)
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return -EINVAL;
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write_lock_bh(&idev->lock);
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if (idev->dead) {
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err = -ENODEV;
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goto out;
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}
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for (aca = idev->ac_list; aca; aca = aca->aca_next) {
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if (ipv6_addr_equal(&aca->aca_addr, addr)) {
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aca->aca_users++;
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err = 0;
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goto out;
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}
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}
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/*
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* not found: create a new one.
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*/
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aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
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if (aca == NULL) {
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err = -ENOMEM;
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goto out;
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}
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rt = addrconf_dst_alloc(idev, addr, 1);
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if (IS_ERR(rt)) {
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kfree(aca);
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err = PTR_ERR(rt);
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goto out;
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}
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ipv6_addr_copy(&aca->aca_addr, addr);
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aca->aca_idev = idev;
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aca->aca_rt = rt;
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aca->aca_users = 1;
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/* aca_tstamp should be updated upon changes */
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aca->aca_cstamp = aca->aca_tstamp = jiffies;
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atomic_set(&aca->aca_refcnt, 2);
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spin_lock_init(&aca->aca_lock);
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aca->aca_next = idev->ac_list;
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idev->ac_list = aca;
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write_unlock_bh(&idev->lock);
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dst_hold(&rt->u.dst);
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if (ip6_ins_rt(rt, NULL, NULL, NULL))
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dst_release(&rt->u.dst);
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addrconf_join_solict(dev, &aca->aca_addr);
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aca_put(aca);
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return 0;
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out:
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write_unlock_bh(&idev->lock);
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in6_dev_put(idev);
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return err;
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}
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/*
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* device anycast group decrement
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*/
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int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
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{
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struct ifacaddr6 *aca, *prev_aca;
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write_lock_bh(&idev->lock);
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prev_aca = NULL;
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for (aca = idev->ac_list; aca; aca = aca->aca_next) {
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if (ipv6_addr_equal(&aca->aca_addr, addr))
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break;
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prev_aca = aca;
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}
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if (!aca) {
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write_unlock_bh(&idev->lock);
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return -ENOENT;
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}
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if (--aca->aca_users > 0) {
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write_unlock_bh(&idev->lock);
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return 0;
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}
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if (prev_aca)
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prev_aca->aca_next = aca->aca_next;
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else
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idev->ac_list = aca->aca_next;
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write_unlock_bh(&idev->lock);
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addrconf_leave_solict(idev, &aca->aca_addr);
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dst_hold(&aca->aca_rt->u.dst);
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if (ip6_del_rt(aca->aca_rt, NULL, NULL, NULL))
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dst_free(&aca->aca_rt->u.dst);
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else
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dst_release(&aca->aca_rt->u.dst);
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aca_put(aca);
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return 0;
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}
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static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
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{
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int ret;
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struct inet6_dev *idev = in6_dev_get(dev);
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if (idev == NULL)
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return -ENODEV;
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ret = __ipv6_dev_ac_dec(idev, addr);
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in6_dev_put(idev);
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return ret;
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}
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/*
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* check if the interface has this anycast address
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*/
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static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
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{
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struct inet6_dev *idev;
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struct ifacaddr6 *aca;
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idev = in6_dev_get(dev);
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if (idev) {
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read_lock_bh(&idev->lock);
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for (aca = idev->ac_list; aca; aca = aca->aca_next)
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if (ipv6_addr_equal(&aca->aca_addr, addr))
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break;
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read_unlock_bh(&idev->lock);
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in6_dev_put(idev);
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return aca != 0;
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}
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return 0;
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}
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/*
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* check if given interface (or any, if dev==0) has this anycast address
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*/
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int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
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{
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if (dev)
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return ipv6_chk_acast_dev(dev, addr);
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read_lock(&dev_base_lock);
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for (dev=dev_base; dev; dev=dev->next)
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if (ipv6_chk_acast_dev(dev, addr))
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break;
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read_unlock(&dev_base_lock);
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return dev != 0;
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}
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#ifdef CONFIG_PROC_FS
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struct ac6_iter_state {
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struct net_device *dev;
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struct inet6_dev *idev;
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};
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#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
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static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
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{
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struct ifacaddr6 *im = NULL;
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struct ac6_iter_state *state = ac6_seq_private(seq);
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for (state->dev = dev_base, state->idev = NULL;
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state->dev;
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state->dev = state->dev->next) {
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struct inet6_dev *idev;
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idev = in6_dev_get(state->dev);
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if (!idev)
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continue;
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read_lock_bh(&idev->lock);
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im = idev->ac_list;
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if (im) {
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state->idev = idev;
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break;
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}
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read_unlock_bh(&idev->lock);
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}
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return im;
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}
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static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
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{
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struct ac6_iter_state *state = ac6_seq_private(seq);
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im = im->aca_next;
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while (!im) {
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if (likely(state->idev != NULL)) {
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read_unlock_bh(&state->idev->lock);
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in6_dev_put(state->idev);
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}
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state->dev = state->dev->next;
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if (!state->dev) {
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state->idev = NULL;
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break;
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}
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state->idev = in6_dev_get(state->dev);
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if (!state->idev)
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continue;
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read_lock_bh(&state->idev->lock);
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im = state->idev->ac_list;
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}
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return im;
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}
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static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
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{
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struct ifacaddr6 *im = ac6_get_first(seq);
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if (im)
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while (pos && (im = ac6_get_next(seq, im)) != NULL)
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--pos;
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return pos ? NULL : im;
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}
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static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
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{
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read_lock(&dev_base_lock);
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return ac6_get_idx(seq, *pos);
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}
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static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct ifacaddr6 *im;
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im = ac6_get_next(seq, v);
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++*pos;
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return im;
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}
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static void ac6_seq_stop(struct seq_file *seq, void *v)
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{
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struct ac6_iter_state *state = ac6_seq_private(seq);
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if (likely(state->idev != NULL)) {
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read_unlock_bh(&state->idev->lock);
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in6_dev_put(state->idev);
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}
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read_unlock(&dev_base_lock);
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}
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static int ac6_seq_show(struct seq_file *seq, void *v)
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{
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struct ifacaddr6 *im = (struct ifacaddr6 *)v;
|
|
struct ac6_iter_state *state = ac6_seq_private(seq);
|
|
|
|
seq_printf(seq,
|
|
"%-4d %-15s " NIP6_SEQFMT " %5d\n",
|
|
state->dev->ifindex, state->dev->name,
|
|
NIP6(im->aca_addr),
|
|
im->aca_users);
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations ac6_seq_ops = {
|
|
.start = ac6_seq_start,
|
|
.next = ac6_seq_next,
|
|
.stop = ac6_seq_stop,
|
|
.show = ac6_seq_show,
|
|
};
|
|
|
|
static int ac6_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *seq;
|
|
int rc = -ENOMEM;
|
|
struct ac6_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
|
|
|
|
if (!s)
|
|
goto out;
|
|
|
|
rc = seq_open(file, &ac6_seq_ops);
|
|
if (rc)
|
|
goto out_kfree;
|
|
|
|
seq = file->private_data;
|
|
seq->private = s;
|
|
out:
|
|
return rc;
|
|
out_kfree:
|
|
kfree(s);
|
|
goto out;
|
|
}
|
|
|
|
static struct file_operations ac6_seq_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = ac6_seq_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
int __init ac6_proc_init(void)
|
|
{
|
|
if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops))
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void ac6_proc_exit(void)
|
|
{
|
|
proc_net_remove("anycast6");
|
|
}
|
|
#endif
|
|
|