diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /net/ipv6/anycast.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'net/ipv6/anycast.c')
| -rw-r--r-- | net/ipv6/anycast.c | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c new file mode 100644 index 000000000..be6dac8a8 --- /dev/null +++ b/net/ipv6/anycast.c @@ -0,0 +1,656 @@ +// 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 <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/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 <linux/slab.h> + +#include <net/net_namespace.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> + +#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); + +#define ac_dereference(a, idev) \ + rcu_dereference_protected(a, lockdep_is_held(&(idev)->lock)) + +static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr); + +static u32 inet6_acaddr_hash(const struct net *net, + const struct in6_addr *addr) +{ + u32 val = __ipv6_addr_jhash(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 ipv6_ac_socklist *pac = NULL; + struct net *net = sock_net(sk); + netdevice_tracker dev_tracker; + struct net_device *dev = NULL; + struct inet6_dev *idev; + int err = 0, ishost; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + if (ipv6_addr_is_multicast(addr)) + return -EINVAL; + + if (ifindex) + dev = netdev_get_by_index(net, ifindex, &dev_tracker, GFP_KERNEL); + + if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE)) { + err = -EINVAL; + goto error; + } + + pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL); + if (!pac) { + err = -ENOMEM; + goto error; + } + + pac->acl_next = NULL; + pac->acl_addr = *addr; + + ishost = !READ_ONCE(net->ipv6.devconf_all->forwarding); + + if (ifindex == 0) { + struct rt6_info *rt; + + rcu_read_lock(); + rt = rt6_lookup(net, addr, NULL, 0, NULL, 0); + if (rt) { + dev = dst_dev_rcu(&rt->dst); + netdev_hold(dev, &dev_tracker, GFP_ATOMIC); + ip6_rt_put(rt); + } else if (ishost) { + rcu_read_unlock(); + err = -EADDRNOTAVAIL; + goto error; + } else { + /* router, no matching interface: just pick one */ + dev = netdev_get_by_flags_rcu(net, &dev_tracker, IFF_UP, + IFF_UP | IFF_LOOPBACK); + } + rcu_read_unlock(); + } + + 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 = !READ_ONCE(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_idev; + } + + err = __ipv6_dev_ac_inc(idev, addr); + if (!err) { + pac->acl_next = np->ipv6_ac_list; + np->ipv6_ac_list = pac; + pac = NULL; + } + +error_idev: + in6_dev_put(idev); +error: + netdev_put(dev, &dev_tracker); + + 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_ac_socklist *pac, *prev_pac; + struct ipv6_pinfo *np = inet6_sk(sk); + struct net *net = sock_net(sk); + struct net_device *dev; + + 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); + 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 *net = sock_net(sk); + struct net_device *dev = NULL; + struct ipv6_ac_socklist *pac; + int prev_index = 0; + + pac = np->ipv6_ac_list; + np->ipv6_ac_list = NULL; + + while (pac) { + struct ipv6_ac_socklist *next = pac->acl_next; + + if (pac->acl_ifindex != prev_index) { + dev_put(dev); + 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; + } + + dev_put(dev); +} + +void ipv6_sock_ac_close(struct sock *sk) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + + if (!np->ipv6_ac_list) + return; + + __ipv6_sock_ac_close(sk); +} + +static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca) +{ + unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr); + + spin_lock_bh(&acaddr_hash_lock); + hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]); + spin_unlock_bh(&acaddr_hash_lock); +} + +static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca) +{ + spin_lock_bh(&acaddr_hash_lock); + hlist_del_init_rcu(&aca->aca_addr_lst); + spin_unlock_bh(&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_hurry(&ac->rcu, aca_free_rcu); +} + +static struct ifacaddr6 *aca_alloc(struct fib6_info *f6i, + const struct in6_addr *addr) +{ + struct ifacaddr6 *aca; + + aca = kzalloc_obj(*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; +} + +static void inet6_ifacaddr_notify(struct net_device *dev, + const struct ifacaddr6 *ifaca, int event) +{ + struct inet6_fill_args fillargs = { + .event = event, + .netnsid = -1, + }; + struct net *net = dev_net(dev); + struct sk_buff *skb; + int err = -ENOMEM; + + skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) + + nla_total_size(sizeof(struct in6_addr)) + + nla_total_size(sizeof(struct ifa_cacheinfo)), + GFP_KERNEL); + if (!skb) + goto error; + + err = inet6_fill_ifacaddr(skb, ifaca, &fillargs); + if (err < 0) { + pr_err("Failed to fill in anycast addresses (err %d)\n", err); + nlmsg_free(skb); + goto error; + } + + rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ACADDR, NULL, GFP_KERNEL); + return; +error: + rtnl_set_sk_err(net, RTNLGRP_IPV6_ACADDR, err); +} + +/* + * 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; + + write_lock_bh(&idev->lock); + if (idev->dead) { + err = -ENODEV; + goto out; + } + + for (aca = ac_dereference(idev->ac_list, idev); aca; + aca = ac_dereference(aca->aca_next, idev)) { + 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, NULL); + 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; + } + + /* Hold this for addrconf_join_solict() below before we unlock, + * it is already exposed via idev->ac_list. + */ + aca_get(aca); + aca->aca_next = idev->ac_list; + rcu_assign_pointer(idev->ac_list, aca); + + ipv6_add_acaddr_hash(net, aca); + + write_unlock_bh(&idev->lock); + + ip6_ins_rt(net, f6i); + + addrconf_join_solict(idev->dev, &aca->aca_addr); + + inet6_ifacaddr_notify(idev->dev, aca, RTM_NEWANYCAST); + + 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; + + write_lock_bh(&idev->lock); + prev_aca = NULL; + for (aca = ac_dereference(idev->ac_list, idev); aca; + aca = ac_dereference(aca->aca_next, idev)) { + 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) + rcu_assign_pointer(prev_aca->aca_next, aca->aca_next); + else + rcu_assign_pointer(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); + + inet6_ifacaddr_notify(idev->dev, aca, RTM_DELANYCAST); + + aca_put(aca); + return 0; +} + +static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr) +{ + struct inet6_dev *idev = in6_dev_get(dev); + int err; + + if (!idev) + return -ENODEV; + + err = __ipv6_dev_ac_dec(idev, addr); + in6_dev_put(idev); + + return err; +} + +void ipv6_ac_destroy_dev(struct inet6_dev *idev) +{ + struct ifacaddr6 *aca; + + write_lock_bh(&idev->lock); + while ((aca = ac_dereference(idev->ac_list, idev)) != NULL) { + rcu_assign_pointer(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) { + for (aca = rcu_dereference(idev->ac_list); aca; + aca = rcu_dereference(aca->aca_next)) + if (ipv6_addr_equal(&aca->aca_addr, addr)) + break; + 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; +}; + +#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private) + +static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq) +{ + struct ac6_iter_state *state = ac6_seq_private(seq); + struct net *net = seq_file_net(seq); + struct ifacaddr6 *im = NULL; + + for_each_netdev_rcu(net, state->dev) { + struct inet6_dev *idev; + + idev = __in6_dev_get(state->dev); + if (!idev) + continue; + im = rcu_dereference(idev->ac_list); + if (im) + break; + } + return im; +} + +static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im) +{ + struct ac6_iter_state *state = ac6_seq_private(seq); + struct inet6_dev *idev; + + im = rcu_dereference(im->aca_next); + while (!im) { + state->dev = next_net_device_rcu(state->dev); + if (!state->dev) + break; + idev = __in6_dev_get(state->dev); + if (!idev) + continue; + im = rcu_dereference(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) +{ + 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_bh(&acaddr_hash_lock); + for (i = 0; i < IN6_ADDR_HSIZE; i++) + WARN_ON(!hlist_empty(&inet6_acaddr_lst[i])); + spin_unlock_bh(&acaddr_hash_lock); +} |
