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7f6c40391a
Add extack info for IPv6 address add/delete, which would be useful for users to understand the problem without having to read kernel code. Suggested-by: Beniamino Galvani <bgalvani@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
619 lines
13 KiB
C
619 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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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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#include <linux/capability.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/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 <linux/slab.h>
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#include <net/net_namespace.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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#define IN6_ADDR_HSIZE_SHIFT 8
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#define IN6_ADDR_HSIZE BIT(IN6_ADDR_HSIZE_SHIFT)
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/* anycast address hash table
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*/
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static struct hlist_head inet6_acaddr_lst[IN6_ADDR_HSIZE];
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static DEFINE_SPINLOCK(acaddr_hash_lock);
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static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
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static u32 inet6_acaddr_hash(struct net *net, const struct in6_addr *addr)
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{
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u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net);
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return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
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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, const 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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struct net *net = sock_net(sk);
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int ishost = !net->ipv6.devconf_all->forwarding;
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int err = 0;
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ASSERT_RTNL();
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if (!ns_capable(net->user_ns, 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 (ifindex)
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dev = __dev_get_by_index(net, ifindex);
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if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
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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)
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return -ENOMEM;
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pac->acl_next = NULL;
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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(net, addr, NULL, 0, NULL, 0);
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if (rt) {
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dev = rt->dst.dev;
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ip6_rt_put(rt);
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} else if (ishost) {
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err = -EADDRNOTAVAIL;
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goto error;
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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(net, IFF_UP,
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IFF_UP | IFF_LOOPBACK);
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}
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}
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if (!dev) {
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err = -ENODEV;
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goto error;
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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 error;
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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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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 (!ipv6_chk_prefix(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 error;
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}
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err = __ipv6_dev_ac_inc(idev, addr);
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if (!err) {
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pac->acl_next = np->ipv6_ac_list;
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np->ipv6_ac_list = pac;
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pac = NULL;
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}
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error:
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if (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, const 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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struct net *net = sock_net(sk);
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ASSERT_RTNL();
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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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return -ENOENT;
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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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dev = __dev_get_by_index(net, 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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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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struct net *net = sock_net(sk);
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int prev_index;
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ASSERT_RTNL();
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pac = np->ipv6_ac_list;
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np->ipv6_ac_list = NULL;
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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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dev = __dev_get_by_index(net, 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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}
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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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if (!np->ipv6_ac_list)
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return;
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rtnl_lock();
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__ipv6_sock_ac_close(sk);
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rtnl_unlock();
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}
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static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca)
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{
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unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr);
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spin_lock(&acaddr_hash_lock);
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hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]);
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spin_unlock(&acaddr_hash_lock);
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}
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static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca)
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{
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spin_lock(&acaddr_hash_lock);
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hlist_del_init_rcu(&aca->aca_addr_lst);
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spin_unlock(&acaddr_hash_lock);
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}
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static void aca_get(struct ifacaddr6 *aca)
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{
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refcount_inc(&aca->aca_refcnt);
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}
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static void aca_free_rcu(struct rcu_head *h)
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{
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struct ifacaddr6 *aca = container_of(h, struct ifacaddr6, rcu);
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fib6_info_release(aca->aca_rt);
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kfree(aca);
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}
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static void aca_put(struct ifacaddr6 *ac)
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{
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if (refcount_dec_and_test(&ac->aca_refcnt)) {
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call_rcu(&ac->rcu, aca_free_rcu);
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}
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}
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static struct ifacaddr6 *aca_alloc(struct fib6_info *f6i,
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const struct in6_addr *addr)
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{
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struct ifacaddr6 *aca;
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aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
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if (!aca)
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return NULL;
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aca->aca_addr = *addr;
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fib6_info_hold(f6i);
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aca->aca_rt = f6i;
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INIT_HLIST_NODE(&aca->aca_addr_lst);
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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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refcount_set(&aca->aca_refcnt, 1);
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return aca;
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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 inet6_dev *idev, const struct in6_addr *addr)
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{
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struct ifacaddr6 *aca;
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struct fib6_info *f6i;
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struct net *net;
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int err;
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ASSERT_RTNL();
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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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net = dev_net(idev->dev);
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f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC, NULL);
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if (IS_ERR(f6i)) {
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err = PTR_ERR(f6i);
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goto out;
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}
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aca = aca_alloc(f6i, addr);
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if (!aca) {
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fib6_info_release(f6i);
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err = -ENOMEM;
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goto out;
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}
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aca->aca_next = idev->ac_list;
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idev->ac_list = aca;
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/* Hold this for addrconf_join_solict() below before we unlock,
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* it is already exposed via idev->ac_list.
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*/
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aca_get(aca);
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write_unlock_bh(&idev->lock);
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ipv6_add_acaddr_hash(net, aca);
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ip6_ins_rt(net, f6i);
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addrconf_join_solict(idev->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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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, const struct in6_addr *addr)
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{
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struct ifacaddr6 *aca, *prev_aca;
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ASSERT_RTNL();
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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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ipv6_del_acaddr_hash(aca);
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addrconf_leave_solict(idev, &aca->aca_addr);
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ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
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aca_put(aca);
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return 0;
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}
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/* called with rtnl_lock() */
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static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
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{
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struct inet6_dev *idev = __in6_dev_get(dev);
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if (!idev)
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return -ENODEV;
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return __ipv6_dev_ac_dec(idev, addr);
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}
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void ipv6_ac_destroy_dev(struct inet6_dev *idev)
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{
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struct ifacaddr6 *aca;
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write_lock_bh(&idev->lock);
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while ((aca = idev->ac_list) != NULL) {
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idev->ac_list = aca->aca_next;
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write_unlock_bh(&idev->lock);
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ipv6_del_acaddr_hash(aca);
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addrconf_leave_solict(idev, &aca->aca_addr);
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ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
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aca_put(aca);
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write_lock_bh(&idev->lock);
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}
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write_unlock_bh(&idev->lock);
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}
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/*
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* check if the interface has this anycast address
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* called with rcu_read_lock()
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*/
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static bool ipv6_chk_acast_dev(struct net_device *dev, const 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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return aca != NULL;
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}
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return false;
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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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bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
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const struct in6_addr *addr)
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{
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struct net_device *nh_dev;
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struct ifacaddr6 *aca;
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bool found = false;
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rcu_read_lock();
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if (dev)
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found = ipv6_chk_acast_dev(dev, addr);
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else {
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unsigned int hash = inet6_acaddr_hash(net, addr);
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hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash],
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aca_addr_lst) {
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nh_dev = fib6_info_nh_dev(aca->aca_rt);
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if (!nh_dev || !net_eq(dev_net(nh_dev), net))
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continue;
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if (ipv6_addr_equal(&aca->aca_addr, addr)) {
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found = true;
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break;
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}
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}
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}
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rcu_read_unlock();
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return found;
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}
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|
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/* check if this anycast address is link-local on given interface or
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* is global
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*/
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bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
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const struct in6_addr *addr)
|
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{
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return ipv6_chk_acast_addr(net,
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(ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
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dev : NULL),
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addr);
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}
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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 seq_net_private p;
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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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struct net *net = seq_file_net(seq);
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state->idev = NULL;
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for_each_netdev_rcu(net, state->dev) {
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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);
|
|
im = idev->ac_list;
|
|
if (im) {
|
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state->idev = idev;
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break;
|
|
}
|
|
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)
|
|
{
|
|
struct ac6_iter_state *state = ac6_seq_private(seq);
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|
|
|
im = im->aca_next;
|
|
while (!im) {
|
|
if (likely(state->idev != NULL))
|
|
read_unlock_bh(&state->idev->lock);
|
|
|
|
state->dev = next_net_device_rcu(state->dev);
|
|
if (!state->dev) {
|
|
state->idev = NULL;
|
|
break;
|
|
}
|
|
state->idev = __in6_dev_get(state->dev);
|
|
if (!state->idev)
|
|
continue;
|
|
read_lock_bh(&state->idev->lock);
|
|
im = state->idev->ac_list;
|
|
}
|
|
return im;
|
|
}
|
|
|
|
static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
|
|
{
|
|
struct ifacaddr6 *im = ac6_get_first(seq);
|
|
if (im)
|
|
while (pos && (im = ac6_get_next(seq, im)) != NULL)
|
|
--pos;
|
|
return pos ? NULL : im;
|
|
}
|
|
|
|
static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
|
|
__acquires(RCU)
|
|
{
|
|
rcu_read_lock();
|
|
return ac6_get_idx(seq, *pos);
|
|
}
|
|
|
|
static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct ifacaddr6 *im = ac6_get_next(seq, v);
|
|
|
|
++*pos;
|
|
return im;
|
|
}
|
|
|
|
static void ac6_seq_stop(struct seq_file *seq, void *v)
|
|
__releases(RCU)
|
|
{
|
|
struct ac6_iter_state *state = ac6_seq_private(seq);
|
|
|
|
if (likely(state->idev != NULL)) {
|
|
read_unlock_bh(&state->idev->lock);
|
|
state->idev = NULL;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static int ac6_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct ifacaddr6 *im = (struct ifacaddr6 *)v;
|
|
struct ac6_iter_state *state = ac6_seq_private(seq);
|
|
|
|
seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
|
|
state->dev->ifindex, state->dev->name,
|
|
&im->aca_addr, im->aca_users);
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations ac6_seq_ops = {
|
|
.start = ac6_seq_start,
|
|
.next = ac6_seq_next,
|
|
.stop = ac6_seq_stop,
|
|
.show = ac6_seq_show,
|
|
};
|
|
|
|
int __net_init ac6_proc_init(struct net *net)
|
|
{
|
|
if (!proc_create_net("anycast6", 0444, net->proc_net, &ac6_seq_ops,
|
|
sizeof(struct ac6_iter_state)))
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void ac6_proc_exit(struct net *net)
|
|
{
|
|
remove_proc_entry("anycast6", net->proc_net);
|
|
}
|
|
#endif
|
|
|
|
/* Init / cleanup code
|
|
*/
|
|
int __init ipv6_anycast_init(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < IN6_ADDR_HSIZE; i++)
|
|
INIT_HLIST_HEAD(&inet6_acaddr_lst[i]);
|
|
return 0;
|
|
}
|
|
|
|
void ipv6_anycast_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
spin_lock(&acaddr_hash_lock);
|
|
for (i = 0; i < IN6_ADDR_HSIZE; i++)
|
|
WARN_ON(!hlist_empty(&inet6_acaddr_lst[i]));
|
|
spin_unlock(&acaddr_hash_lock);
|
|
}
|