1 files changed, 594 insertions, 0 deletions

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
new file mode 100644
index 000000000000..5d22ca3cca2e
--- /dev/null
+++ b/net/ipv6/anycast.c
@@ -0,0 +1,594 @@
+/*
+ *      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 <linux/seq_file.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>
+
+static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
+
+/* Big ac list lock for all the sockets */
+static DEFINE_RWLOCK(ipv6_sk_ac_lock);
+
+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 = ipv6_prefix_equal(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 = inet6_sk(sk);
+        struct net_device *dev = NULL;
+        struct inet6_dev *idev;
+        struct ipv6_ac_socklist *pac;
+        int     ishost = !ipv6_devconf.forwarding;
+        int     err = 0;
+
+        if (!capable(CAP_NET_ADMIN))
+                return -EPERM;
+        if (ipv6_addr_is_multicast(addr))
+                return -EINVAL;
+        if (ipv6_chk_addr(addr, NULL, 0))
+                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) {
+                        err = -EADDRNOTAVAIL;
+                        goto out_free_pac;
+                } 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) {
+                err = -ENODEV;
+                goto out_free_pac;
+        }
+
+        idev = in6_dev_get(dev);
+        if (!idev) {
+                if (ifindex)
+                        err = -ENODEV;
+                else
+                        err = -EADDRNOTAVAIL;
+                goto out_dev_put;
+        }
+        /* 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.
+         */
+        if (!ip6_onlink(addr, dev)) {
+                if (ishost)
+                        err = -EADDRNOTAVAIL;
+                if (err)
+                        goto out_dev_put;
+        }
+
+        err = ipv6_dev_ac_inc(dev, addr);
+        if (err)
+                goto out_dev_put;
+
+        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;
+
+out_dev_put:
+        dev_put(dev);
+out_free_pac:
+        sock_kfree_s(sk, pac, sizeof(*pac));
+        return err;
+}
+
+/*
+ *      socket leave an anycast group
+ */
+int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
+{
+        struct ipv6_pinfo *np = inet6_sk(sk);
+        struct net_device *dev;
+        struct ipv6_ac_socklist *pac, *prev_pac;
+
+        write_lock_bh(&ipv6_sk_ac_lock);
+        prev_pac = NULL;
+        for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
+                if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
+                     ipv6_addr_equal(&pac->acl_addr, addr))
+                        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 = inet6_sk(sk);
+        struct net_device *dev = NULL;
+        struct ipv6_ac_socklist *pac;
+        int     prev_index;
+
+        write_lock_bh(&ipv6_sk_ac_lock);
+        pac = np->ipv6_ac_list;
+        np->ipv6_ac_list = NULL;
+        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);
+}
+
+#if 0
+/* The function is not used, which is funny. Apparently, author
+ * supposed to use it to filter out datagrams inside udp/raw but forgot.
+ *
+ * It is OK, anycasts are not special comparing to delivery to unicasts.
+ */
+
+int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
+{
+        struct ipv6_ac_socklist *pac;
+        struct ipv6_pinfo *np = inet6_sk(sk);
+        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_equal(&pac->acl_addr, addr);
+                if (found)
+                        break;
+        }
+        read_unlock(&ipv6_sk_ac_lock);
+
+        return found;
+}
+
+#endif
+
+static void aca_put(struct ifacaddr6 *ac)
+{
+        if (atomic_dec_and_test(&ac->aca_refcnt)) {
+                in6_dev_put(ac->aca_idev);
+                dst_release(&ac->aca_rt->u.dst);
+                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;
+        struct rt6_info *rt;
+        int err;
+
+        idev = in6_dev_get(dev);
+
+        if (idev == NULL)
+                return -EINVAL;
+
+        write_lock_bh(&idev->lock);
+        if (idev->dead) {
+                err = -ENODEV;
+                goto out;
+        }
+
+        for (aca = idev->ac_list; aca; aca = aca->aca_next) {
+                if (ipv6_addr_equal(&aca->aca_addr, addr)) {
+                        aca->aca_users++;
+                        err = 0;
+                        goto out;
+                }
+        }
+
+        /*
+         *      not found: create a new one.
+         */
+
+        aca = kmalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
+
+        if (aca == NULL) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        rt = addrconf_dst_alloc(idev, addr, 1);
+        if (IS_ERR(rt)) {
+                kfree(aca);
+                err = PTR_ERR(rt);
+                goto out;
+        }
+
+        memset(aca, 0, sizeof(struct ifacaddr6));
+
+        ipv6_addr_copy(&aca->aca_addr, addr);
+        aca->aca_idev = idev;
+        aca->aca_rt = rt;
+        aca->aca_users = 1;
+        /* aca_tstamp should be updated upon changes */
+        aca->aca_cstamp = aca->aca_tstamp = jiffies;
+        atomic_set(&aca->aca_refcnt, 2);
+        spin_lock_init(&aca->aca_lock);
+
+        aca->aca_next = idev->ac_list;
+        idev->ac_list = aca;
+        write_unlock_bh(&idev->lock);
+
+        dst_hold(&rt->u.dst);
+        if (ip6_ins_rt(rt, NULL, NULL))
+                dst_release(&rt->u.dst);
+
+        addrconf_join_solict(dev, &aca->aca_addr);
+
+        aca_put(aca);
+        return 0;
+out:
+        write_unlock_bh(&idev->lock);
+        in6_dev_put(idev);
+        return err;
+}
+
+/*
+ *      device anycast group decrement
+ */
+int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
+{
+        struct ifacaddr6 *aca, *prev_aca;
+
+        write_lock_bh(&idev->lock);
+        prev_aca = NULL;
+        for (aca = idev->ac_list; aca; aca = aca->aca_next) {
+                if (ipv6_addr_equal(&aca->aca_addr, addr))
+                        break;
+                prev_aca = aca;
+        }
+        if (!aca) {
+                write_unlock_bh(&idev->lock);
+                return -ENOENT;
+        }
+        if (--aca->aca_users > 0) {
+                write_unlock_bh(&idev->lock);
+                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(idev, &aca->aca_addr);
+
+        dst_hold(&aca->aca_rt->u.dst);
+        if (ip6_del_rt(aca->aca_rt, NULL, NULL))
+                dst_free(&aca->aca_rt->u.dst);
+        else
+                dst_release(&aca->aca_rt->u.dst);
+
+        aca_put(aca);
+        return 0;
+}
+
+static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
+{
+        int ret;
+        struct inet6_dev *idev = in6_dev_get(dev);
+        if (idev == NULL)
+                return -ENODEV;
+        ret = __ipv6_dev_ac_dec(idev, addr);
+        in6_dev_put(idev);
+        return ret;
+}
+        
+/*
+ *      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_equal(&aca->aca_addr, addr))
+                                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
+struct ac6_iter_state {
+        struct net_device *dev;
+        struct inet6_dev *idev;
+};
+
+#define ac6_seq_private(seq)    ((struct ac6_iter_state *)(seq)->private)
+
+static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
+{
+        struct ifacaddr6 *im = NULL;
+        struct ac6_iter_state *state = ac6_seq_private(seq);
+
+        for (state->dev = dev_base, state->idev = NULL;
+             state->dev;
+             state->dev = state->dev->next) {
+                struct inet6_dev *idev;
+                idev = in6_dev_get(state->dev);
+                if (!idev)
+                        continue;
+                read_lock_bh(&idev->lock);
+                im = idev->ac_list;
+                if (im) {
+                        state->idev = idev;
+                        break;
+                }
+                read_unlock_bh(&idev->lock);
+        }
+        return im;
+}
+
+static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
+{
+        struct ac6_iter_state *state = ac6_seq_private(seq);
+
+        im = im->aca_next;
+        while (!im) {
+                if (likely(state->idev != NULL)) {
+                        read_unlock_bh(&state->idev->lock);
+                        in6_dev_put(state->idev);
+                }
+                state->dev = state->dev->next;
+                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)
+{
+        read_lock(&dev_base_lock);
+        return ac6_get_idx(seq, *pos);
+}
+
+static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct ifacaddr6 *im;
+        im = ac6_get_next(seq, v);
+        ++*pos;
+        return im;
+}
+
+static void ac6_seq_stop(struct seq_file *seq, void *v)
+{
+        struct ac6_iter_state *state = ac6_seq_private(seq);
+        if (likely(state->idev != NULL)) {
+                read_unlock_bh(&state->idev->lock);
+                in6_dev_put(state->idev);
+        }
+        read_unlock(&dev_base_lock);
+}
+
+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 "
+                   "%04x%04x%04x%04x%04x%04x%04x%04x "
+                   "%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 = kmalloc(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;
+        memset(s, 0, sizeof(*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
+