From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/ipv6/anycast.c | 619 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 619 insertions(+) create mode 100644 net/ipv6/anycast.c (limited to 'net/ipv6/anycast.c') diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c new file mode 100644 index 000000000..dacdea7fc --- /dev/null +++ b/net/ipv6/anycast.c @@ -0,0 +1,619 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Anycast support for IPv6 + * Linux INET6 implementation + * + * Authors: + * David L Stevens (dlstevens@us.ibm.com) + * + * based heavily on net/ipv6/mcast.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include + +#define IN6_ADDR_HSIZE_SHIFT 8 +#define IN6_ADDR_HSIZE BIT(IN6_ADDR_HSIZE_SHIFT) +/* anycast address hash table + */ +static struct hlist_head inet6_acaddr_lst[IN6_ADDR_HSIZE]; +static DEFINE_SPINLOCK(acaddr_hash_lock); + +static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr); + +static u32 inet6_acaddr_hash(struct net *net, const struct in6_addr *addr) +{ + u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net); + + return hash_32(val, IN6_ADDR_HSIZE_SHIFT); +} + +/* + * socket join an anycast group + */ + +int ipv6_sock_ac_join(struct sock *sk, int ifindex, const 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; + struct net *net = sock_net(sk); + int ishost = !net->ipv6.devconf_all->forwarding; + int err = 0; + + ASSERT_RTNL(); + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + if (ipv6_addr_is_multicast(addr)) + return -EINVAL; + + if (ifindex) + dev = __dev_get_by_index(net, ifindex); + + if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE)) + return -EINVAL; + + pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL); + if (!pac) + return -ENOMEM; + pac->acl_next = NULL; + pac->acl_addr = *addr; + + if (ifindex == 0) { + struct rt6_info *rt; + + rt = rt6_lookup(net, addr, NULL, 0, NULL, 0); + if (rt) { + dev = rt->dst.dev; + ip6_rt_put(rt); + } else if (ishost) { + err = -EADDRNOTAVAIL; + goto error; + } else { + /* router, no matching interface: just pick one */ + dev = __dev_get_by_flags(net, IFF_UP, + IFF_UP | IFF_LOOPBACK); + } + } + + if (!dev) { + err = -ENODEV; + goto error; + } + + idev = __in6_dev_get(dev); + if (!idev) { + if (ifindex) + err = -ENODEV; + else + err = -EADDRNOTAVAIL; + goto error; + } + /* reset ishost, now that we have a specific device */ + ishost = !idev->cnf.forwarding; + + 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 (!ipv6_chk_prefix(addr, dev)) { + if (ishost) + err = -EADDRNOTAVAIL; + if (err) + goto error; + } + + err = __ipv6_dev_ac_inc(idev, addr); + if (!err) { + pac->acl_next = np->ipv6_ac_list; + np->ipv6_ac_list = pac; + pac = NULL; + } + +error: + if (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, const struct in6_addr *addr) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct net_device *dev; + struct ipv6_ac_socklist *pac, *prev_pac; + struct net *net = sock_net(sk); + + ASSERT_RTNL(); + + 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) + return -ENOENT; + if (prev_pac) + prev_pac->acl_next = pac->acl_next; + else + np->ipv6_ac_list = pac->acl_next; + + dev = __dev_get_by_index(net, pac->acl_ifindex); + if (dev) + ipv6_dev_ac_dec(dev, &pac->acl_addr); + + 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; + struct net *net = sock_net(sk); + int prev_index; + + ASSERT_RTNL(); + pac = np->ipv6_ac_list; + np->ipv6_ac_list = NULL; + + prev_index = 0; + while (pac) { + struct ipv6_ac_socklist *next = pac->acl_next; + + if (pac->acl_ifindex != prev_index) { + dev = __dev_get_by_index(net, 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; + } +} + +void ipv6_sock_ac_close(struct sock *sk) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + + if (!np->ipv6_ac_list) + return; + rtnl_lock(); + __ipv6_sock_ac_close(sk); + rtnl_unlock(); +} + +static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca) +{ + unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr); + + spin_lock(&acaddr_hash_lock); + hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]); + spin_unlock(&acaddr_hash_lock); +} + +static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca) +{ + spin_lock(&acaddr_hash_lock); + hlist_del_init_rcu(&aca->aca_addr_lst); + spin_unlock(&acaddr_hash_lock); +} + +static void aca_get(struct ifacaddr6 *aca) +{ + refcount_inc(&aca->aca_refcnt); +} + +static void aca_free_rcu(struct rcu_head *h) +{ + struct ifacaddr6 *aca = container_of(h, struct ifacaddr6, rcu); + + fib6_info_release(aca->aca_rt); + kfree(aca); +} + +static void aca_put(struct ifacaddr6 *ac) +{ + if (refcount_dec_and_test(&ac->aca_refcnt)) { + call_rcu(&ac->rcu, aca_free_rcu); + } +} + +static struct ifacaddr6 *aca_alloc(struct fib6_info *f6i, + const struct in6_addr *addr) +{ + struct ifacaddr6 *aca; + + aca = kzalloc(sizeof(*aca), GFP_ATOMIC); + if (!aca) + return NULL; + + aca->aca_addr = *addr; + fib6_info_hold(f6i); + aca->aca_rt = f6i; + INIT_HLIST_NODE(&aca->aca_addr_lst); + aca->aca_users = 1; + /* aca_tstamp should be updated upon changes */ + aca->aca_cstamp = aca->aca_tstamp = jiffies; + refcount_set(&aca->aca_refcnt, 1); + + return aca; +} + +/* + * device anycast group inc (add if not found) + */ +int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr) +{ + struct ifacaddr6 *aca; + struct fib6_info *f6i; + struct net *net; + int err; + + ASSERT_RTNL(); + + 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; + } + } + + net = dev_net(idev->dev); + f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC); + if (IS_ERR(f6i)) { + err = PTR_ERR(f6i); + goto out; + } + aca = aca_alloc(f6i, addr); + if (!aca) { + fib6_info_release(f6i); + err = -ENOMEM; + goto out; + } + + aca->aca_next = idev->ac_list; + idev->ac_list = aca; + + /* Hold this for addrconf_join_solict() below before we unlock, + * it is already exposed via idev->ac_list. + */ + aca_get(aca); + write_unlock_bh(&idev->lock); + + ipv6_add_acaddr_hash(net, aca); + + ip6_ins_rt(net, f6i); + + addrconf_join_solict(idev->dev, &aca->aca_addr); + + aca_put(aca); + return 0; +out: + write_unlock_bh(&idev->lock); + return err; +} + +/* + * device anycast group decrement + */ +int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr) +{ + struct ifacaddr6 *aca, *prev_aca; + + ASSERT_RTNL(); + + 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); + ipv6_del_acaddr_hash(aca); + addrconf_leave_solict(idev, &aca->aca_addr); + + ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false); + + aca_put(aca); + return 0; +} + +/* called with rtnl_lock() */ +static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr) +{ + struct inet6_dev *idev = __in6_dev_get(dev); + + if (!idev) + return -ENODEV; + return __ipv6_dev_ac_dec(idev, addr); +} + +void ipv6_ac_destroy_dev(struct inet6_dev *idev) +{ + struct ifacaddr6 *aca; + + write_lock_bh(&idev->lock); + while ((aca = idev->ac_list) != NULL) { + idev->ac_list = aca->aca_next; + write_unlock_bh(&idev->lock); + + ipv6_del_acaddr_hash(aca); + + addrconf_leave_solict(idev, &aca->aca_addr); + + ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false); + + aca_put(aca); + + write_lock_bh(&idev->lock); + } + write_unlock_bh(&idev->lock); +} + +/* + * check if the interface has this anycast address + * called with rcu_read_lock() + */ +static bool ipv6_chk_acast_dev(struct net_device *dev, const 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); + return aca != NULL; + } + return false; +} + +/* + * check if given interface (or any, if dev==0) has this anycast address + */ +bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev, + const struct in6_addr *addr) +{ + struct net_device *nh_dev; + struct ifacaddr6 *aca; + bool found = false; + + rcu_read_lock(); + if (dev) + found = ipv6_chk_acast_dev(dev, addr); + else { + unsigned int hash = inet6_acaddr_hash(net, addr); + + hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash], + aca_addr_lst) { + nh_dev = fib6_info_nh_dev(aca->aca_rt); + if (!nh_dev || !net_eq(dev_net(nh_dev), net)) + continue; + if (ipv6_addr_equal(&aca->aca_addr, addr)) { + found = true; + break; + } + } + } + rcu_read_unlock(); + return found; +} + +/* check if this anycast address is link-local on given interface or + * is global + */ +bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev, + const struct in6_addr *addr) +{ + return ipv6_chk_acast_addr(net, + (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ? + dev : NULL), + addr); +} + +#ifdef CONFIG_PROC_FS +struct ac6_iter_state { + struct seq_net_private p; + 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); + struct net *net = seq_file_net(seq); + + state->idev = NULL; + for_each_netdev_rcu(net, state->dev) { + 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); + + 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); +} -- cgit v1.2.3