Add 'struct fib6_result' to hold the fib entry and fib6_nh from a fib
lookup as separate entries, similar to what IPv4 now has with fib_result.

Rename fib6_multipath_select to fib6_select_path, pass fib6_result to
it, and set f6i and nh in the result once a path selection is done.
Call fib6_select_path unconditionally for path selection which means
moving the sibling and oif check to fib6_select_path. To handle the two
different call paths (2 only call multipath_select if flowi6_oif == 0 and
the other always calls it), add a new have_oif_match that controls the
sibling walk if relevant.

Update callers of fib6_multipath_select accordingly and have them use the
fib6_info and fib6_nh from the result.

This is needed for multipath nexthop objects where a single f6i can
point to multiple fib6_nh (similar to IPv4).
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rt6_probe sends probes for gateways in a nexthop. As such it really
depends on a fib6_nh, not a fib entry. Move last_probe to fib6_nh and
update rt6_probe to a fib6_nh struct.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add fib_nh_common struct with common nexthop attributes. Convert
fib_nh and fib6_nh to use it. Use macros to move existing
fib_nh_* references to the new nh_common.nhc_*.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename fib6_nh entries that will be moved to a fib_nh_common struct.
Specifically, the device, gateway, flags, and lwtstate are common
with all nexthop definitions. In some places new temporary variables
are declared or local variables renamed to maintain line lengths.

Rename only; no functional change intended.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The gateway setting is not per fib6_info entry but per-fib6_nh. Add a new
fib_nh_has_gw flag to fib6_nh and convert references to RTF_GATEWAY to
the new flag. For IPv6 address the flag is cheaper than checking that
nh_gw is non-0 like IPv4 does.

While this increases fib6_nh by 8-bytes, the effective allocation size of
a fib6_info is unchanged. The 8 bytes is recovered later with a
fib_nh_common change.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the fib6_nh cleanup code to a new helper, fib6_nh_release.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to IPv4, consolidate the fib6_nh initialization into a helper.
As a new standalone function, add a cleanup path to put lwtstate on
error.

To avoid modifying fib6_config flags, move the reject check to a helper
that is invoked once by fib6_nh_init to reset the device and then
again in ip6_route_info_create to set the fib6_flags.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change addrconf_f6i_alloc to generate a fib6_config and call
ip6_route_info_create. addrconf_f6i_alloc is the last caller to
fib6_info_alloc besides ip6_route_info_create, and there is no
reason for it to do its own initialization on a fib6_info.

Host routes need to be created even if the device is down, so add a
new flag, fc_ignore_dev_down, to fib6_config and update fib6_nh_init
to not error out if device is not up.

Notes on the conversion:
- ip_fib_metrics_init is the same as fib6_config has fc_mx set to NULL
  and fc_mx_len set to 0
- dst_nocount is handled by the RTF_ADDRCONF flag
- dst_host is handled by fc_dst_len = 128

nh_gw does not get set after the conversion to ip6_route_info_create
but it should not be set in addrconf_f6i_alloc since this is a host
route not a gateway route.

Everything else is a straight forward map between fib6_info and
fib6_config.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When commit 27097255 ("[IPV6]: ROUTE: Add Router Reachability
Probing (RFC4191).") introduced router probing, the rt6_probe() function
required that a neighbour entry existed. This neighbour entry is used to
record the timestamp of the last probe via the ->updated field.

Later, commit 2152caea ("ipv6: Do not depend on rt->n in rt6_probe().")
removed the requirement for a neighbour entry. Neighbourless routes skip
the interval check and are not rate-limited.

This patch adds rate-limiting for neighbourless routes, by recording the
timestamp of the last probe in the fib6_info itself.

Fixes: 2152caea ("ipv6: Do not depend on rt->n in rt6_probe().")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Another difference between IPv4 and IPv6 is the generation of RTM_DELROUTE
notifications when a device is taken down (admin down) or deleted. IPv4
does not generate a message for routes evicted by the down or delete;
IPv6 does. A NOS at scale really needs to avoid these messages and have
IPv4 and IPv6 behave similarly, relying on userspace to handle link
notifications and evict the routes.

At this point existing user behavior needs to be preserved. Since
notifications are a global action (not per app) the only way to preserve
existing behavior and allow the messages to be skipped is to add a new
sysctl (net/ipv6/route/skip_notify_on_dev_down) which can be set to
disable the notificatioons.

IPv6 route code already supports the option to skip the message (it is
used for multipath routes for example). Besides the new sysctl we need
to pass the skip_notify setting through the generic fib6_clean and
fib6_walk functions to fib6_clean_node and to set skip_notify on calls
to __ip_del_rt for the addrconf_ifdown path.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The fib6_info reference in rt6_info is rcu protected. Add a helper
to extract prefsrc from and update cxgbi_check_route6 to use it.

Fixes: 0153167a ("net/ipv6: Remove rt6i_prefsrc")
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the conversion to fib6_info, rt6i_prefsrc has a single user that
reads the value and otherwise it is only set. The one reader can be
converted to use rt->from so rt6i_prefsrc can be removed, reducing
rt6_info by another 20 bytes.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the code path where only rcu read lock is held, e.g. in the route
lookup code path, it is not safe to directly call fib6_info_hold()
because the fib6_info may already have been deleted but still exists
in the rcu grace period. Holding reference to it could cause double
free and crash the kernel.

This patch adds a new function fib6_info_hold_safe() and replace
fib6_info_hold() in all necessary places.

Syzbot reported 3 crash traces because of this. One of them is:
8021q: adding VLAN 0 to HW filter on device team0
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
dst_release: dst:(____ptrval____) refcnt:-1
dst_release: dst:(____ptrval____) refcnt:-2
WARNING: CPU: 1 PID: 4845 at include/net/dst.h:239 dst_hold include/net/dst.h:239 [inline]
WARNING: CPU: 1 PID: 4845 at include/net/dst.h:239 ip6_setup_cork+0xd66/0x1830 net/ipv6/ip6_output.c:1204
dst_release: dst:(____ptrval____) refcnt:-1
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4845 Comm: syz-executor493 Not tainted 4.18.0-rc3+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
dst_release: dst:(____ptrval____) refcnt:-2
dst_release: dst:(____ptrval____) refcnt:-3
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
dst_release: dst:(____ptrval____) refcnt:-4
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
dst_release: dst:(____ptrval____) refcnt:-5
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:dst_hold include/net/dst.h:239 [inline]
RIP: 0010:ip6_setup_cork+0xd66/0x1830 net/ipv6/ip6_output.c:1204
Code: c1 ed 03 89 9d 18 ff ff ff 48 b8 00 00 00 00 00 fc ff df 41 c6 44 05 00 f8 e9 2d 01 00 00 4c 8b a5 c8 fe ff ff e8 1a f6 e6 fa <0f> 0b e9 6a fc ff ff e8 0e f6 e6 fa 48 8b 85 d0 fe ff ff 48 8d 78
RSP: 0018:ffff8801a8fcf178 EFLAGS: 00010293
RAX: ffff8801a8eba5c0 RBX: 0000000000000000 RCX: ffffffff869511e6
RDX: 0000000000000000 RSI: ffffffff869515b6 RDI: 0000000000000005
RBP: ffff8801a8fcf2c8 R08: ffff8801a8eba5c0 R09: ffffed0035ac8338
R10: ffffed0035ac8338 R11: ffff8801ad6419c3 R12: ffff8801a8fcf720
R13: ffff8801a8fcf6a0 R14: ffff8801ad6419c0 R15: ffff8801ad641980
 ip6_make_skb+0x2c8/0x600 net/ipv6/ip6_output.c:1768
 udpv6_sendmsg+0x2c90/0x35f0 net/ipv6/udp.c:1376
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:651
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2125
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2220
 __do_sys_sendmmsg net/socket.c:2249 [inline]
 __se_sys_sendmmsg net/socket.c:2246 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2246
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446ba9
Code: e8 cc bb 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb39a469da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc54 RCX: 0000000000446ba9
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc50 R08: 00007fb39a46a700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 45c828efc7a64843
R13: e6eeb815b9d8a477 R14: 5068caf6f713c6fc R15: 0000000000000001
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 93531c67 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: syzbot+902e2a1bcd4f7808cef5@syzkaller.appspotmail.com
Reported-by: syzbot+8ae62d67f647abeeceb9@syzkaller.appspotmail.com
Reported-by: syzbot+3f08feb14086930677d0@syzkaller.appspotmail.com
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported use after free that is caused by fib6_info being
freed without a proper RCU grace period.

CPU: 0 PID: 1407 Comm: udevd Not tainted 4.17.0+ #39
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __read_once_size include/linux/compiler.h:188 [inline]
 find_rr_leaf net/ipv6/route.c:705 [inline]
 rt6_select net/ipv6/route.c:761 [inline]
 fib6_table_lookup+0x12b7/0x14d0 net/ipv6/route.c:1823
 ip6_pol_route+0x1c2/0x1020 net/ipv6/route.c:1856
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2082
 fib6_rule_lookup+0x211/0x6d0 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2110
 ip6_route_output include/net/ip6_route.h:82 [inline]
 icmpv6_xrlim_allow net/ipv6/icmp.c:211 [inline]
 icmp6_send+0x147c/0x2da0 net/ipv6/icmp.c:535
 icmpv6_send+0x17a/0x300 net/ipv6/ip6_icmp.c:43
 ip6_link_failure+0xa5/0x790 net/ipv6/route.c:2244
 dst_link_failure include/net/dst.h:427 [inline]
 ndisc_error_report+0xd1/0x1c0 net/ipv6/ndisc.c:695
 neigh_invalidate+0x246/0x550 net/core/neighbour.c:892
 neigh_timer_handler+0xaf9/0xde0 net/core/neighbour.c:978
 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0x79e/0xc50 kernel/time/timer.c:1666
 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d1/0x200 kernel/softirq.c:404
 exiting_irq arch/x86/include/asm/apic.h:527 [inline]
 smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:strlen+0x5e/0xa0 lib/string.c:482
Code: 24 00 74 3b 48 bb 00 00 00 00 00 fc ff df 4c 89 e0 48 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38 ca 7f 04 <84> d2 75 23 80 38 00 75 de 48 83 c4 08 4c 29 e0 5b 41 5c 5d c3 48
RSP: 0018:ffff8801af117850 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff880197f53bd0 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81c5b06c RDI: ffff880197f53bc0
RBP: ffff8801af117868 R08: ffff88019a976540 R09: 0000000000000000
R10: ffff88019a976540 R11: 0000000000000000 R12: ffff880197f53bc0
R13: ffff880197f53bc0 R14: ffffffff899e4e90 R15: ffff8801d91c6a00
 strlen include/linux/string.h:267 [inline]
 getname_kernel+0x24/0x370 fs/namei.c:218
 open_exec+0x17/0x70 fs/exec.c:882
 load_elf_binary+0x968/0x5610 fs/binfmt_elf.c:780
 search_binary_handler+0x17d/0x570 fs/exec.c:1653
 exec_binprm fs/exec.c:1695 [inline]
 __do_execve_file.isra.35+0x16fe/0x2710 fs/exec.c:1819
 do_execveat_common fs/exec.c:1866 [inline]
 do_execve fs/exec.c:1883 [inline]
 __do_sys_execve fs/exec.c:1964 [inline]
 __se_sys_execve fs/exec.c:1959 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f1576a46207
Code: 77 19 f4 48 89 d7 44 89 c0 0f 05 48 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 f7 d8 64 41 89 01 eb df b8 3b 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 00 8c 2d 00 f7 d8 64 89 02
RSP: 002b:00007ffff2784568 EFLAGS: 00000202 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f1576a46207
RDX: 0000000001215b10 RSI: 00007ffff2784660 RDI: 00007ffff2785670
RBP: 0000000000625500 R08: 000000000000589c R09: 000000000000589c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000001215b10
R13: 0000000000000007 R14: 0000000001204250 R15: 0000000000000005

Allocated by task 12188:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
 kmalloc include/linux/slab.h:513 [inline]
 kzalloc include/linux/slab.h:706 [inline]
 fib6_info_alloc+0xbb/0x280 net/ipv6/ip6_fib.c:152
 ip6_route_info_create+0x782/0x2b50 net/ipv6/route.c:3013
 ip6_route_add+0x23/0xb0 net/ipv6/route.c:3154
 ipv6_route_ioctl+0x5a5/0x760 net/ipv6/route.c:3660
 inet6_ioctl+0x100/0x1f0 net/ipv6/af_inet6.c:546
 sock_do_ioctl+0xe4/0x3e0 net/socket.c:973
 sock_ioctl+0x30d/0x680 net/socket.c:1097
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 1402:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 fib6_info_destroy+0x29b/0x350 net/ipv6/ip6_fib.c:207
 fib6_info_release include/net/ip6_fib.h:286 [inline]
 __ip6_del_rt_siblings net/ipv6/route.c:3235 [inline]
 ip6_route_del+0x11c4/0x13b0 net/ipv6/route.c:3316
 ipv6_route_ioctl+0x616/0x760 net/ipv6/route.c:3663
 inet6_ioctl+0x100/0x1f0 net/ipv6/af_inet6.c:546
 sock_do_ioctl+0xe4/0x3e0 net/socket.c:973
 sock_ioctl+0x30d/0x680 net/socket.c:1097
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801b5df2580
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 8 bytes inside of
 256-byte region [ffff8801b5df2580, ffff8801b5df2680)
The buggy address belongs to the page:
page:ffffea0006d77c80 count:1 mapcount:0 mapping:ffff8801da8007c0 index:0xffff8801b5df2e40
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006c5cc48 ffffea0007363308 ffff8801da8007c0
raw: ffff8801b5df2e40 ffff8801b5df2080 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b5df2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801b5df2500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
> ffff8801b5df2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8801b5df2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801b5df2680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb

Fixes: a64efe14 ("net/ipv6: introduce fib6_info struct and helpers")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@gmail.com>
Reported-by: syzbot+9e6d75e3edef427ee888@syzkaller.appspotmail.com
Acked-by: NDavid Ahern <dsahern@gmail.com>
Tested-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.

Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules,
but returns a FIB entry, fib6_info, rather than a dst based rt6_info.
fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled)
to 60% faster than any of the dst based lookup methods (without custom
rules) and 25% faster with custom rules (e.g., l3mdev rule).

Since the lookup function has a completely different signature,
fib6_rule_action is split into 2 paths: the existing one is
renamed __fib6_rule_action and a new one for the fib6_info path
is added. fib6_rule_action decides which to call based on the
lookup_ptr. If it is fib6_table_lookup then the new path is taken.

Caller must hold rcu lock as no reference is taken on the returned
fib entry.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

ip6_pol_route is used for ingress and egress FIB lookups. Refactor it
moving the table lookup into a separate fib6_table_lookup that can be
invoked separately and export the new function.

ip6_pol_route now calls fib6_table_lookup and uses the result to generate
a dst based rt6_info.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rename rt6_multipath_select to fib6_multipath_select and export it.
A later patch wants access to it similar to IPv4's fib_select_path.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rename fib6_lookup to fib6_node_lookup to better reflect what it
returns. The fib6_lookup name will be used in a later patch for
an IPv6 equivalent to IPv4's fib_lookup.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This slipped through the cracks in the followup set to the fib6_info flip.
Rename rt6_next to fib6_next.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a dst entry is created from a fib entry, the 'from' in rt6_info
is set to the fib entry. The 'from' reference is used most notably for
cookie checking - making sure stale dst entries are updated if the
fib entry is changed.

When a fib entry is deleted, the pcpu routes on it are walked releasing
the fib6_info reference. This is needed for the fib6_info cleanup to
happen and to make sure all device references are released in a timely
manner.

There is a race window when a FIB entry is deleted and the 'from' on the
pcpu route is dropped and the pcpu route hits a cookie check. Handle
this race using rcu on from.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A later patch protects 'from' in rt6_info and this simplifies the
locking needed by it.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rt6_get_cookie_safe takes a fib6_info and checks the sernum of
the node. Update the name to reflect its purpose.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rt6_clean_expires and rt6_set_expires are no longer used. Removed them.
rt6_update_expires has 1 caller in route.c, so move it from the header.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib6_idev can be obtained from __in6_dev_get on the nexthop device
rather than caching it in the fib6_info. Remove it.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

aca_idev has only 1 user - inet6_fill_ifacaddr - and it only
wants the device index which can be extracted from the fib6_info
nexthop.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the prefix for fib6_info struct elements from rt6i_ to fib6_.
rt6i_pcpu and rt6i_exception_bucket are left as is given that they
point to rt6_info entries.

Rename only; not functional change intended.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop unneeded elements from rt6_info struct and rearrange layout to
something more relevant for the data path.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert all code paths referencing a FIB entry from
rt6_info to fib6_info.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Last step before flipping the data type for FIB entries:
- use fib6_info_alloc to create FIB entries in ip6_route_info_create
  and addrconf_dst_alloc
- use fib6_info_release in place of dst_release, ip6_rt_put and
  rt6_release
- remove the dst_hold before calling __ip6_ins_rt or ip6_del_rt
- when purging routes, drop per-cpu routes
- replace inc and dec of rt6i_ref with fib6_info_hold and fib6_info_release
- use rt->from since it points to the FIB entry
- drop references to exception bucket, fib6_metrics and per-cpu from
  dst entries (those are relevant for fib entries only)
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add fib6_info struct and alloc, destroy, hold and release helpers.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Continuing to wean FIB paths off of dst_entry, use a bool to hold
requests for certain dst settings. Add a helper to convert the
flags to DST flags when a FIB entry is converted to a dst_entry.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add expires to rt6_info for FIB entries, and add fib6 helpers to
manage it. Data path use of dst.expires remains.

The transition is fairly straightforward: when working with fib entries,
rt->dst.expires is just rt->expires, rt6_clean_expires is replaced with
fib6_clean_expires, rt6_set_expires becomes fib6_set_expires, and
rt6_check_expired becomes fib6_check_expired, where the fib6 versions
are added by this patch.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to IPv4, add fib metrics to the fib struct, which at the moment
is rt6_info. Will be moved to fib6_info in a later patch. Copy metrics
into dst by reference using refcount.

To make the transition:
- add dst_metrics to rt6_info. Default to dst_default_metrics if no
  metrics are passed during route add. No need for a separate pmtu
  entry; it can reference the MTU slot in fib6_metrics

- ip6_convert_metrics allocates memory in the FIB entry and uses
  ip_metrics_convert to copy from netlink attribute to metrics entry

- the convert metrics call is done in ip6_route_info_create simplifying
  the route add path
  + fib6_commit_metrics and fib6_copy_metrics and the temporary
    mx6_config are no longer needed

- add fib6_metric_set helper to change the value of a metric in the
  fib entry since dst_metric_set can no longer be used

- cow_metrics for IPv6 can drop to dst_cow_metrics_generic

- rt6_dst_from_metrics_check is no longer needed

- rt6_fill_node needs the FIB entry and dst as separate arguments to
  keep compatibility with existing output. Current dst address is
  renamed to dest.
  (to be consistent with IPv4 rt6_fill_node really should be split
  into 2 functions similar to fib_dump_info and rt_fill_info)

- rt6_fill_node no longer needs the temporary metrics variable
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce fib6_nh structure and move nexthop related data from
rt6_info and rt6_info.dst to fib6_nh. References to dev, gateway or
lwtstate from a FIB lookup perspective are converted to use fib6_nh;
datapath references to dst version are left as is.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RTN_ type for IPv6 FIB entries is currently embedded in rt6i_flags
and dst.error. Since dst is going to be removed, it can no longer be
relied on for FIB dumps so save the route type as fib6_type.

fc_type is set in current users based on the algorithm in rt6_fill_node:
  - rt6i_flags contains RTF_LOCAL: fc_type = RTN_LOCAL
  - rt6i_flags contains RTF_ANYCAST: fc_type = RTN_ANYCAST
  - else fc_type = RTN_UNICAST

Similarly, fib6_type is set in the rt6_info templates based on the
RTF_REJECT section of rt6_fill_node converting dst.error to RTN type.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass net namespace to fib6_update_sernum. It can not be marked const
as fib6_new_sernum will change ipv6.fib6_sernum.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 does path selection for multipath routes deep in the lookup
functions. The next patch adds L4 hash option and needs the skb
for the forward path. To get the skb to the relevant FIB lookup
functions it needs to go through the fib rules layer, so add a
lookup_data argument to the fib_lookup_arg struct.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dissect flow in fwd path if fib rules require it. Controlled by
a flag to avoid penatly for the common case. Flag is set when fib
rules with sport, dport and proto match that require flow dissect
are installed. Also passes the dissected hash keys to the multipath
hash function when applicable to avoid dissecting the flow again.
icmp packets will continue to use inner header for hash
calculations.
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>