| /* |
| * 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/capability.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 = kzalloc(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; |
| } |
| |
| 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)) |
| 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, 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 " 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 |
| |