kernel/linux.git/include/net/addrconf.h, branch v6.18.21

ipv6: Add __in6_dev_get_rtnl_net().

2025-01-20T20:16:04+00:00

We will convert rtnl_lock() with rtnl_net_lock(), and we want to convert __in6_dev_get() too. __in6_dev_get() uses rcu_dereference_rtnl(), but as written in its comment, rtnl_dereference() or rcu_dereference() is preferable. Let's add __in6_dev_get_rtnl_net() that uses rtnl_net_dereference(). We can add the RCU version helper later if needed. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250115080608.28127-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

netlink: add IPv6 anycast join/leave notifications

2025-01-09T11:54:45+00:00

This change introduces a mechanism for notifying userspace applications about changes to IPv6 anycast addresses via netlink. It includes: * Addition and deletion of IPv6 anycast addresses are reported using RTM_NEWANYCAST and RTM_DELANYCAST. * A new netlink group (RTNLGRP_IPV6_ACADDR) for subscribing to these notifications. This enables user space applications(e.g. ip monitor) to efficiently track anycast addresses through netlink messages, improving metrics collection and system monitoring. It also unlocks the potential for advanced anycast management in user space, such as hardware offload control and fine grained network control. Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Signed-off-by: Yuyang Huang Reviewed-by: David Ahern Link: https://patch.msgid.link/20250107114355.1766086-1-yuyanghuang@google.com Signed-off-by: Paolo Abeni

netlink: add IGMP/MLD join/leave notifications

2024-12-15T12:31:35+00:00

This change introduces netlink notifications for multicast address changes. The following features are included: * Addition and deletion of multicast addresses are reported using RTM_NEWMULTICAST and RTM_DELMULTICAST messages with AF_INET and AF_INET6. * Two new notification groups: RTNLGRP_IPV4_MCADDR and RTNLGRP_IPV6_MCADDR are introduced for receiving these events. This change allows user space applications (e.g., ip monitor) to efficiently track multicast group memberships by listening for netlink events. Previously, applications relied on inefficient polling of procfs, introducing delays. With netlink notifications, applications receive realtime updates on multicast group membership changes, enabling more precise metrics collection and system monitoring. This change also unlocks the potential for implementing a wide range of sophisticated multicast related features in user space by allowing applications to combine kernel provided multicast address information with user space data and communicate decisions back to the kernel for more fine grained control. This mechanism can be used for various purposes, including multicast filtering, IGMP/MLD offload, and IGMP/MLD snooping. Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Co-developed-by: Patrick Ruddy Signed-off-by: Patrick Ruddy Link: https://lore.kernel.org/r/20180906091056.21109-1-pruddy@vyatta.att-mail.com Signed-off-by: Yuyang Huang Signed-off-by: David S. Miller

net: Correct spelling in headers

2024-08-26T16:37:23+00:00

Correct spelling in Networking headers. As reported by codespell. Signed-off-by: Simon Horman Link: https://patch.msgid.link/20240822-net-spell-v1-12-3a98971ce2d2@kernel.org Signed-off-by: Jakub Kicinski

ip: Move INFINITY_LIFE_TIME to addrconf.h.

2024-08-16T01:56:14+00:00

INFINITY_LIFE_TIME is the common value used in IPv4 and IPv6 but defined in both .c files. Also, 0xffffffff used in addrconf_timeout_fixup() is INFINITY_LIFE_TIME. Let's move INFINITY_LIFE_TIME's definition to addrconf.h Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20240809235406.50187-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

Add support for PIO p flag

2024-07-31T12:49:48+00:00

draft-ietf-6man-pio-pflag is adding a new flag to the Prefix Information Option to signal that the network can allocate a unique IPv6 prefix per client via DHCPv6-PD (see draft-ietf-v6ops-dhcp-pd-per-device). When ra_honor_pio_pflag is enabled, the presence of a P-flag causes SLAAC autoconfiguration to be disabled for that particular PIO. An automated test has been added in Android (r.android.com/3195335) to go along with this change. Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Cc: David Lamparter Cc: Simon Horman Signed-off-by: Patrick Rohr Reviewed-by: Maciej Żenczykowski Signed-off-by: David S. Miller

ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr

2024-04-10T00:09:05+00:00

Although ipv6_get_ifaddr walks inet6_addr_lst under the RCU lock, it still means hlist_for_each_entry_rcu can return an item that got removed from the list. The memory itself of such item is not freed thanks to RCU but nothing guarantees the actual content of the memory is sane. In particular, the reference count can be zero. This can happen if ipv6_del_addr is called in parallel. ipv6_del_addr removes the entry from inet6_addr_lst (hlist_del_init_rcu(&ifp->addr_lst)) and drops all references (__in6_ifa_put(ifp) + in6_ifa_put(ifp)). With bad enough timing, this can happen: 1. In ipv6_get_ifaddr, hlist_for_each_entry_rcu returns an entry. 2. Then, the whole ipv6_del_addr is executed for the given entry. The reference count drops to zero and kfree_rcu is scheduled. 3. ipv6_get_ifaddr continues and tries to increments the reference count (in6_ifa_hold). 4. The rcu is unlocked and the entry is freed. 5. The freed entry is returned. Prevent increasing of the reference count in such case. The name in6_ifa_hold_safe is chosen to mimic the existing fib6_info_hold_safe. [ 41.506330] refcount_t: addition on 0; use-after-free. [ 41.506760] WARNING: CPU: 0 PID: 595 at lib/refcount.c:25 refcount_warn_saturate+0xa5/0x130 [ 41.507413] Modules linked in: veth bridge stp llc [ 41.507821] CPU: 0 PID: 595 Comm: python3 Not tainted 6.9.0-rc2.main-00208-g49563be82afa #14 [ 41.508479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) [ 41.509163] RIP: 0010:refcount_warn_saturate+0xa5/0x130 [ 41.509586] Code: ad ff 90 0f 0b 90 90 c3 cc cc cc cc 80 3d c0 30 ad 01 00 75 a0 c6 05 b7 30 ad 01 01 90 48 c7 c7 38 cc 7a 8c e8 cc 18 ad ff 90 <0f> 0b 90 90 c3 cc cc cc cc 80 3d 98 30 ad 01 00 0f 85 75 ff ff ff [ 41.510956] RSP: 0018:ffffbda3c026baf0 EFLAGS: 00010282 [ 41.511368] RAX: 0000000000000000 RBX: ffff9e9c46914800 RCX: 0000000000000000 [ 41.511910] RDX: ffff9e9c7ec29c00 RSI: ffff9e9c7ec1c900 RDI: ffff9e9c7ec1c900 [ 41.512445] RBP: ffff9e9c43660c9c R08: 0000000000009ffb R09: 00000000ffffdfff [ 41.512998] R10: 00000000ffffdfff R11: ffffffff8ca58a40 R12: ffff9e9c4339a000 [ 41.513534] R13: 0000000000000001 R14: ffff9e9c438a0000 R15: ffffbda3c026bb48 [ 41.514086] FS: 00007fbc4cda1740(0000) GS:ffff9e9c7ec00000(0000) knlGS:0000000000000000 [ 41.514726] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.515176] CR2: 000056233b337d88 CR3: 000000000376e006 CR4: 0000000000370ef0 [ 41.515713] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 41.516252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 41.516799] Call Trace: [ 41.517037] [ 41.517249] ? __warn+0x7b/0x120 [ 41.517535] ? refcount_warn_saturate+0xa5/0x130 [ 41.517923] ? report_bug+0x164/0x190 [ 41.518240] ? handle_bug+0x3d/0x70 [ 41.518541] ? exc_invalid_op+0x17/0x70 [ 41.520972] ? asm_exc_invalid_op+0x1a/0x20 [ 41.521325] ? refcount_warn_saturate+0xa5/0x130 [ 41.521708] ipv6_get_ifaddr+0xda/0xe0 [ 41.522035] inet6_rtm_getaddr+0x342/0x3f0 [ 41.522376] ? __pfx_inet6_rtm_getaddr+0x10/0x10 [ 41.522758] rtnetlink_rcv_msg+0x334/0x3d0 [ 41.523102] ? netlink_unicast+0x30f/0x390 [ 41.523445] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 41.523832] netlink_rcv_skb+0x53/0x100 [ 41.524157] netlink_unicast+0x23b/0x390 [ 41.524484] netlink_sendmsg+0x1f2/0x440 [ 41.524826] __sys_sendto+0x1d8/0x1f0 [ 41.525145] __x64_sys_sendto+0x1f/0x30 [ 41.525467] do_syscall_64+0xa5/0x1b0 [ 41.525794] entry_SYSCALL_64_after_hwframe+0x72/0x7a [ 41.526213] RIP: 0033:0x7fbc4cfcea9a [ 41.526528] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89 [ 41.527942] RSP: 002b:00007ffcf54012a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 41.528593] RAX: ffffffffffffffda RBX: 00007ffcf5401368 RCX: 00007fbc4cfcea9a [ 41.529173] RDX: 000000000000002c RSI: 00007fbc4b9d9bd0 RDI: 0000000000000005 [ 41.529786] RBP: 00007fbc4bafb040 R08: 00007ffcf54013e0 R09: 000000000000000c [ 41.530375] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 41.530977] R13: ffffffffc4653600 R14: 0000000000000001 R15: 00007fbc4ca85d1b [ 41.531573] Fixes: 5c578aedcb21d ("IPv6: convert addrconf hash list to RCU") Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: Jiri Benc Link: https://lore.kernel.org/r/8ab821e36073a4a406c50ec83c9e8dc586c539e4.1712585809.git.jbenc@redhat.com Signed-off-by: Jakub Kicinski

ipv6: annotate data-races around idev->cnf.ignore_routes_with_linkdown

2024-03-01T08:42:32+00:00

idev->cnf.ignore_routes_with_linkdown can be used without any locks, add appropriate annotations. Signed-off-by: Eric Dumazet Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

net: ipv6/addrconf: introduce a regen_min_advance sysctl

2024-02-15T14:34:40+00:00

In RFC 8981, REGEN_ADVANCE cannot be less than 2 seconds, and the RFC does not permit the creation of temporary addresses with lifetimes shorter than that: > When processing a Router Advertisement with a > Prefix Information option carrying a prefix for the purposes of > address autoconfiguration (i.e., the A bit is set), the host MUST > perform the following steps: > 5. A temporary address is created only if this calculated preferred > lifetime is greater than REGEN_ADVANCE time units. However, some users want to change their IPv6 address as frequently as possible regardless of the RFC's arbitrary minimum lifetime. For the benefit of those users, add a regen_min_advance sysctl parameter that can be set to below or above 2 seconds. Link: https://datatracker.ietf.org/doc/html/rfc8981 Signed-off-by: Alex Henrie Reviewed-by: David Ahern Signed-off-by: Paolo Abeni

net: ipv6: support reporting otherwise unknown prefix flags in RTM_NEWPREFIX

2023-12-08T10:40:51+00:00

Lorenzo points out that we effectively clear all unknown flags from PIO when copying them to userspace in the netlink RTM_NEWPREFIX notification. We could fix this one at a time as new flags are defined, or in one fell swoop - I choose the latter. We could either define 6 new reserved flags (reserved1..6) and handle them individually (and rename them as new flags are defined), or we could simply copy the entire unmodified byte over - I choose the latter. This unfortunately requires some anonymous union/struct magic, so we add a static assert on the struct size for a little extra safety. Cc: David Ahern Cc: Lorenzo Colitti Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Maciej Żenczykowski Reviewed-by: David Ahern Signed-off-by: David S. Miller