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-rw-r--r--net/ipv6/anycast.c594
1 files changed, 594 insertions, 0 deletions
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
new file mode 100644
index 0000000..5d22ca3
--- /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
+
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