The previous bug fix had an unfortunate side effect that broke
distribution of binding table entries between nodes. The updated
tipc_sock_addr struct is also used further down in the same
function, and there the old value is still the correct one.

Fixes: 032062f3 ("tipc: fix wrong publisher node address in link publications")
Signed-off-by: NJon Maloy <jmaloy@redhat.com>
Link: https://lore.kernel.org/r/20220216020009.3404578-1-jmaloy@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

When a link comes up we add its presence to the name table to make it
possible for users to subscribe for link up/down events. However, after
a previous call signature change the binding is wrongly published with
the peer node as publishing node, instead of the own node as it should
be. This has the effect that the command 'tipc name table show' will
list the link binding (service type 2) with node scope and a peer node
as originator, something that obviously is impossible.

We correct this bug here.

Fixes: 50a3499a ("tipc: simplify signature of tipc_namtbl_publish()")
Signed-off-by: NJon Maloy <jmaloy@redhat.com>
Link: https://lore.kernel.org/r/20220214013852.2803940-1-jmaloy@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Fix the use of indefinite article.
Signed-off-by: Ngushengxian <gushengxian@yulong.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The using of the node address and node link identity are not thread safe,
meaning that two publications may be published the same values, as result
one of them will get failure because of already existing in the name table.
To avoid this we have to use the node address and node link identity values
from inside the node item's write lock protection.

Fixes: 50a3499a ("tipc: simplify signature of tipc_namtbl_publish()")
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These patches fix a series of spelling errors in net/tipc module.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

s/synching/syncing/
Signed-off-by: NBhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Following the principles of the preceding commits, we reduce
the number of parameters passed along in tipc_sk_withdraw(),
tipc_nametbl_withdraw() and associated functions.
Signed-off-by: NJon Maloy <jmaloy@redhat.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NHoang Le <hoang.h.le@dektech.com.au>
Acked-by: NTung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using the new address structure tipc_uaddr, we simplify the signature
of function tipc_sk_publish() and tipc_namtbl_publish() so that fewer
parameters need to be passed around.
Signed-off-by: NJon Maloy <jmaloy@redhat.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NHoang Le <hoang.h.le@dektech.com.au>
Acked-by: NTung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before calling tipc_aead_key_size(ptr), we need to ensure
we have enough data to dereference ptr->keylen.

We probably also want to make sure tipc_aead_key_size()
wont overflow with malicious ptr->keylen values.

Syzbot reported:

BUG: KMSAN: uninit-value in __tipc_nl_node_set_key net/tipc/node.c:2971 [inline]
BUG: KMSAN: uninit-value in tipc_nl_node_set_key+0x9bf/0x13b0 net/tipc/node.c:3023
CPU: 0 PID: 21060 Comm: syz-executor.5 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 __tipc_nl_node_set_key net/tipc/node.c:2971 [inline]
 tipc_nl_node_set_key+0x9bf/0x13b0 net/tipc/node.c:3023
 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
 genl_rcv_msg+0x1319/0x1610 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x6fa/0x810 net/netlink/af_netlink.c:2494
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11d6/0x14a0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x1740/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x714/0x830 net/socket.c:2432
 __compat_sys_sendmsg net/compat.c:347 [inline]
 __do_compat_sys_sendmsg net/compat.c:354 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351
 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline]
 __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:141
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:166
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:209
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f60549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f555a5fc EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000200
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2907 [inline]
 __kmalloc_node_track_caller+0xa37/0x1430 mm/slub.c:4527
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2f8/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1099 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline]
 netlink_sendmsg+0xdbc/0x1840 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x714/0x830 net/socket.c:2432
 __compat_sys_sendmsg net/compat.c:347 [inline]
 __do_compat_sys_sendmsg net/compat.c:354 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351
 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline]
 __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:141
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:166
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:209
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Fixes: e1f32190 ("tipc: add support for AEAD key setting via netlink")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Tuong Lien <tuong.t.lien@dektech.com.au>
Cc: Jon Maloy <jmaloy@redhat.com>
Cc: Ying Xue <ying.xue@windriver.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the following warning from sparse:

net/tipc/monitor.c:263:35: warning: incorrect type in assignment (different base types)
net/tipc/monitor.c:263:35:    expected unsigned int
net/tipc/monitor.c:263:35:    got restricted __be32 [usertype]
[...]
net/tipc/node.c:374:13: warning: context imbalance in 'tipc_node_read_lock' - wrong count at exit
net/tipc/node.c:379:13: warning: context imbalance in 'tipc_node_read_unlock' - unexpected unlock
net/tipc/node.c:384:13: warning: context imbalance in 'tipc_node_write_lock' - wrong count at exit
net/tipc/node.c:389:13: warning: context imbalance in 'tipc_node_write_unlock_fast' - unexpected unlock
net/tipc/node.c:404:17: warning: context imbalance in 'tipc_node_write_unlock' - unexpected unlock
[...]
net/tipc/crypto.c:1201:9: warning: incorrect type in initializer (different address spaces)
net/tipc/crypto.c:1201:9:    expected struct tipc_aead [noderef] __rcu *__tmp
net/tipc/crypto.c:1201:9:    got struct tipc_aead *
[...]
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NHoang Huu Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A function has a different name between their prototype
and its kernel-doc markup:

	../net/tipc/link.c:2551: warning: expecting prototype for link_reset_stats(). Prototype was for tipc_link_reset_stats() instead
	../net/tipc/node.c:1678: warning: expecting prototype for is the general link level function for message sending(). Prototype was for tipc_node_xmit() instead
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

`tipc_node_apply_property` does a null check on a `tipc_link_entry`
pointer but also accesses the same pointer out of the null check block.

This triggers a warning on Coverity Static Analyzer because we're
implying that `e->link` can BE null.

Move "Update MTU for node link entry" line into if block to make sure
that we're not in a state that `e->link` is null.
Signed-off-by: NCengiz Can <cengiz@kernel.wtf>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We add the support to remove a specific node down with 128bit
node identifier, as an alternative to legacy 32-bit node address.

example:
$tipc peer remove identiy <1001002|16777777>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Link: https://lore.kernel.org/r/20201203035045.4564-1-hoang.h.le@dektech.com.auSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Fix Return: kernel-doc notation in all net/tipc/ source files.
Also keep ReST list notation intact for output formatting.
Fix a few typos in comments.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Fix node.c kernel-doc warnings in preparation for adding to the
networking docbook.

../net/tipc/node.c:141: warning: Function parameter or member 'kref' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'bc_entry' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'failover_sent' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'peer_id' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'peer_id_string' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'conn_sks' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'keepalive_intv' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'timer' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'peer_net' not described in 'tipc_node'
../net/tipc/node.c:141: warning: Function parameter or member 'peer_hash_mix' not described in 'tipc_node'
../net/tipc/node.c:273: warning: Function parameter or member '__n' not described in 'tipc_node_crypto_rx'
../net/tipc/node.c:822: warning: Function parameter or member 'n' not described in '__tipc_node_link_up'
../net/tipc/node.c:822: warning: Function parameter or member 'bearer_id' not described in '__tipc_node_link_up'
../net/tipc/node.c:822: warning: Function parameter or member 'xmitq' not described in '__tipc_node_link_up'
../net/tipc/node.c:888: warning: Function parameter or member 'n' not described in 'tipc_node_link_up'
../net/tipc/node.c:888: warning: Function parameter or member 'bearer_id' not described in 'tipc_node_link_up'
../net/tipc/node.c:888: warning: Function parameter or member 'xmitq' not described in 'tipc_node_link_up'
../net/tipc/node.c:948: warning: Function parameter or member 'n' not described in '__tipc_node_link_down'
../net/tipc/node.c:948: warning: Function parameter or member 'bearer_id' not described in '__tipc_node_link_down'
../net/tipc/node.c:948: warning: Function parameter or member 'xmitq' not described in '__tipc_node_link_down'
../net/tipc/node.c:948: warning: Function parameter or member 'maddr' not described in '__tipc_node_link_down'
../net/tipc/node.c:1537: warning: Function parameter or member 'net' not described in 'tipc_node_get_linkname'
../net/tipc/node.c:1537: warning: Function parameter or member 'len' not described in 'tipc_node_get_linkname'
../net/tipc/node.c:1891: warning: Function parameter or member 'n' not described in 'tipc_node_check_state'
../net/tipc/node.c:1891: warning: Function parameter or member 'xmitq' not described in 'tipc_node_check_state'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

kernel-doc and Sphinx fixes to eliminate lots of warnings
in preparation for adding to the networking docbook.

../net/tipc/crypto.c:57: warning: cannot understand function prototype: 'enum '
../net/tipc/crypto.c:69: warning: cannot understand function prototype: 'enum '
../net/tipc/crypto.c:130: warning: Function parameter or member 'tfm' not described in 'tipc_tfm'
../net/tipc/crypto.c:130: warning: Function parameter or member 'list' not described in 'tipc_tfm'
../net/tipc/crypto.c:172: warning: Function parameter or member 'stat' not described in 'tipc_crypto_stats'
../net/tipc/crypto.c:232: warning: Function parameter or member 'flags' not described in 'tipc_crypto'
../net/tipc/crypto.c:329: warning: Function parameter or member 'ukey' not described in 'tipc_aead_key_validate'
../net/tipc/crypto.c:329: warning: Function parameter or member 'info' not described in 'tipc_aead_key_validate'
../net/tipc/crypto.c:482: warning: Function parameter or member 'aead' not described in 'tipc_aead_tfm_next'
../net/tipc/trace.c:43: warning: cannot understand function prototype: 'unsigned long sysctl_tipc_sk_filter[5] __read_mostly = '

Documentation/networking/tipc:57: ../net/tipc/msg.c:584: WARNING: Unexpected indentation.
Documentation/networking/tipc:63: ../net/tipc/name_table.c:536: WARNING: Unexpected indentation.
Documentation/networking/tipc:63: ../net/tipc/name_table.c:537: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/networking/tipc:78: ../net/tipc/socket.c:3809: WARNING: Unexpected indentation.
Documentation/networking/tipc:78: ../net/tipc/socket.c:3807: WARNING: Inline strong start-string without end-string.
Documentation/networking/tipc:72: ../net/tipc/node.c:904: WARNING: Unexpected indentation.
Documentation/networking/tipc:39: ../net/tipc/crypto.c:97: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/networking/tipc:39: ../net/tipc/crypto.c:98: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/networking/tipc:39: ../net/tipc/crypto.c:141: WARNING: Inline strong start-string without end-string.

../net/tipc/discover.c:82: warning: Function parameter or member 'skb' not described in 'tipc_disc_init_msg'

../net/tipc/msg.c:69: warning: Function parameter or member 'gfp' not described in 'tipc_buf_acquire'
../net/tipc/msg.c:382: warning: Function parameter or member 'offset' not described in 'tipc_msg_build'
../net/tipc/msg.c:708: warning: Function parameter or member 'net' not described in 'tipc_msg_lookup_dest'

../net/tipc/subscr.c:65: warning: Function parameter or member 'seq' not described in 'tipc_sub_check_overlap'
../net/tipc/subscr.c:65: warning: Function parameter or member 'found_lower' not described in 'tipc_sub_check_overlap'
../net/tipc/subscr.c:65: warning: Function parameter or member 'found_upper' not described in 'tipc_sub_check_overlap'

../net/tipc/udp_media.c:75: warning: Function parameter or member 'proto' not described in 'udp_media_addr'
../net/tipc/udp_media.c:75: warning: Function parameter or member 'port' not described in 'udp_media_addr'
../net/tipc/udp_media.c:75: warning: Function parameter or member 'ipv4' not described in 'udp_media_addr'
../net/tipc/udp_media.c:75: warning: Function parameter or member 'ipv6' not described in 'udp_media_addr'
../net/tipc/udp_media.c:98: warning: Function parameter or member 'rcast' not described in 'udp_bearer'

Also fixed a typo of "duest" to "dest".
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

In commit 682cd3cf
("tipc: confgiure and apply UDP bearer MTU on running links"), we
introduced a function to change UDP bearer MTU and applied this new value
across existing per-link. However, we did not apply this new MTU value at
node level. This lead to packet dropped at link level if its size is
greater than new MTU value.

To fix this issue, we also apply this new MTU value for node level.

Fixes: 682cd3cf ("tipc: confgiure and apply UDP bearer MTU on running links")
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Link: https://lore.kernel.org/r/20201130025544.3602-1-hoang.h.le@dektech.com.auSigned-off-by: NJakub Kicinski <kuba@kernel.org>

A semicolon is not needed after a switch statement.
Signed-off-by: NTom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201101155822.2294856-1-trix@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

In the function node_lost_contact(), we call __skb_queue_purge() without
grabbing the list->lock. This can cause to a race-condition why processing
the list 'namedq' in calling path tipc_named_rcv()->tipc_named_dequeue().

    [] BUG: kernel NULL pointer dereference, address: 0000000000000000
    [] #PF: supervisor read access in kernel mode
    [] #PF: error_code(0x0000) - not-present page
    [] PGD 7ca63067 P4D 7ca63067 PUD 6c553067 PMD 0
    [] Oops: 0000 [#1] SMP NOPTI
    [] CPU: 1 PID: 15 Comm: ksoftirqd/1 Tainted: G  O  5.9.0-rc6+ #2
    [] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS [...]
    [] RIP: 0010:tipc_named_rcv+0x103/0x320 [tipc]
    [] Code: 41 89 44 24 10 49 8b 16 49 8b 46 08 49 c7 06 00 00 00 [...]
    [] RSP: 0018:ffffc900000a7c58 EFLAGS: 00000282
    [] RAX: 00000000000012ec RBX: 0000000000000000 RCX: ffff88807bde1270
    [] RDX: 0000000000002c7c RSI: 0000000000002c7c RDI: ffff88807b38f1a8
    [] RBP: ffff88807b006288 R08: ffff88806a367800 R09: ffff88806a367900
    [] R10: ffff88806a367a00 R11: ffff88806a367b00 R12: ffff88807b006258
    [] R13: ffff88807b00628a R14: ffff888069334d00 R15: ffff88806a434600
    [] FS:  0000000000000000(0000) GS:ffff888079480000(0000) knlGS:0[...]
    [] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [] CR2: 0000000000000000 CR3: 0000000077320000 CR4: 00000000000006e0
    [] Call Trace:
    []  ? tipc_bcast_rcv+0x9a/0x1a0 [tipc]
    []  tipc_rcv+0x40d/0x670 [tipc]
    []  ? _raw_spin_unlock+0xa/0x20
    []  tipc_l2_rcv_msg+0x55/0x80 [tipc]
    []  __netif_receive_skb_one_core+0x8c/0xa0
    []  process_backlog+0x98/0x140
    []  net_rx_action+0x13a/0x420
    []  __do_softirq+0xdb/0x316
    []  ? smpboot_thread_fn+0x2f/0x1e0
    []  ? smpboot_thread_fn+0x74/0x1e0
    []  ? smpboot_thread_fn+0x14e/0x1e0
    []  run_ksoftirqd+0x1a/0x40
    []  smpboot_thread_fn+0x149/0x1e0
    []  ? sort_range+0x20/0x20
    []  kthread+0x131/0x150
    []  ? kthread_unuse_mm+0xa0/0xa0
    []  ret_from_fork+0x22/0x30
    [] Modules linked in: veth tipc(O) ip6_udp_tunnel udp_tunnel [...]
    [] CR2: 0000000000000000
    [] ---[ end trace 65c276a8e2e2f310 ]---

To fix this, we need to grab the lock of the 'namedq' list on both
path calling.

Fixes: cad2929d ("tipc: update a binding service via broadcast")
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NHoang Huu Le <hoang.h.le@dektech.com.au>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Rekeying is required for security since a key is less secure when using
for a long time. Also, key will be detached when its nonce value (or
seqno ...) is exhausted. We now make the rekeying process automatic and
configurable by user.

Basically, TIPC will at a specific interval generate a new key by using
the kernel 'Random Number Generator' cipher, then attach it as the node
TX key and securely distribute to others in the cluster as RX keys (-
the key exchange). The automatic key switching will then take over, and
make the new key active shortly. Afterwards, the traffic from this node
will be encrypted with the new session key. The same can happen in peer
nodes but not necessarily at the same time.

For simplicity, the automatically generated key will be initiated as a
per node key. It is not too hard to also support a cluster key rekeying
(e.g. a given node will generate a unique cluster key and update to the
others in the cluster...), but that doesn't bring much benefit, while a
per-node key is even more secure.

We also enable user to force a rekeying or change the rekeying interval
via netlink, the new 'set key' command option: 'TIPC_NLA_NODE_REKEYING'
is added for these purposes as follows:
- A value >= 1 will be set as the rekeying interval (in minutes);
- A value of 0 will disable the rekeying;
- A value of 'TIPC_REKEYING_NOW' (~0) will force an immediate rekeying;

The default rekeying interval is (60 * 24) minutes i.e. done every day.
There isn't any restriction for the value but user shouldn't set it too
small or too large which results in an "ineffective" rekeying (thats ok
for testing though).
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With support from the master key option in the previous commit, it
becomes easy to make frequent updates/exchanges of session keys between
authenticated cluster nodes.
Basically, there are two situations where the key exchange will take in
place:

- When a new node joins the cluster (with the master key), it will need
  to get its peer's TX key, so that be able to decrypt further messages
  from that peer.

- When a new session key is generated (by either user manual setting or
  later automatic rekeying feature), the key will be distributed to all
  peer nodes in the cluster.

A key to be exchanged is encapsulated in the data part of a 'MSG_CRYPTO
/KEY_DISTR_MSG' TIPC v2 message, then xmit-ed as usual and encrypted by
using the master key before sending out. Upon receipt of the message it
will be decrypted in the same way as regular messages, then attached as
the sender's RX key in the receiver node.

In this way, the key exchange is reliable by the link layer, as well as
security, integrity and authenticity by the crypto layer.

Also, the forward security will be easily achieved by user changing the
master key actively but this should not be required very frequently.

The key exchange feature is independent on the presence of a master key
Note however that the master key still is needed for new nodes to be
able to join the cluster. It is also optional, and can be turned off/on
via the sysfs: 'net/tipc/key_exchange_enabled' [default 1: enabled].

Backward compatibility is guaranteed because for nodes that do not have
master key support, key exchange using master key ie. tx_key = 0 if any
will be shortly discarded at the message validation step. In other
words, the key exchange feature will be automatically disabled to those
nodes.

v2: fix the "implicit declaration of function 'tipc_crypto_key_flush'"
error in node.c. The function only exists when built with the TIPC
"CONFIG_TIPC_CRYPTO" option.

v3: use 'info->extack' for a message emitted due to netlink operations
instead (- David's comment).
Reported-by: Nkernel test robot <lkp@intel.com>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In addition to the supported cluster & per-node encryption keys for the
en/decryption of TIPC messages, we now introduce one option for user to
set a cluster key as 'master key', which is simply a symmetric key like
the former but has a longer life cycle. It has two purposes:

- Authentication of new member nodes in the cluster. New nodes, having
  no knowledge of current session keys in the cluster will still be
  able to join the cluster as long as they know the master key. This is
  because all neighbor discovery (LINK_CONFIG) messages must be
  encrypted with this key.

- Encryption of session encryption keys during automatic exchange and
  update of those.This is a feature we will introduce in a later commit
  in this series.

We insert the new key into the currently unused slot 0 in the key array
and start using it immediately once the user has set it.
After joining, a node only knowing the master key should be fully
communicable to existing nodes in the cluster, although those nodes may
have their own session keys activated (i.e. not the master one). To
support this, we define a 'grace period', starting from the time a node
itself reports having no RX keys, so the existing nodes will use the
master key for encryption instead. The grace period can be extended but
will automatically stop after e.g. 5 seconds without a new report. This
is also the basis for later key exchanging feature as the new node will
be impossible to decrypt anything without the support from master key.

For user to set a master key, we define a new netlink flag -
'TIPC_NLA_NODE_KEY_MASTER', so it can be added to the current 'set key'
netlink command to specify the setting key to be a master key.

Above all, the traditional cluster/per-node key mechanism is guaranteed
to work when user comes not to use this master key option. This is also
compatible to legacy nodes without the feature supported.

Even this master key can be updated without any interruption of cluster
connectivity but is so is needed, this has to be coordinated and set by
the user.
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We reduce the lasting time for a pending TX key to be active as well as
for a passive RX key to be freed which generally helps speed up the key
switching. It is not expected to be too fast but should not be too slow
either. Also the key handling logic is simplified that a pending RX key
will be removed automatically if it is found not working after a number
of times; the probing for a pending TX key is now carried on a specific
message user ('LINK_PROTOCOL' or 'LINK_CONFIG') which is more efficient
than using a timer on broadcast messages, the timer is reserved for use
later as needed.

The kernel logs or 'pr***()' are now made as clear as possible to user.
Some prints are added, removed or changed to the debug-level. The
'TIPC_CRYPTO_DEBUG' definition is removed, and the 'pr_debug()' is used
instead which will be much helpful in runtime.

Besides we also optimize the code in some other places as a preparation
for later commits.

v2: silent more kernel logs, also use 'info->extack' for a message
emitted due to netlink operations instead (- David's comments).
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simple fixes which require no deep knowledge of the code.

Cc: Jon Maloy <jmaloy@redhat.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, updating binding table (add service binding to
name table/withdraw a service binding) is being sent over replicast.
However, if we are scaling up clusters to > 100 nodes/containers this
method is less affection because of looping through nodes in a cluster one
by one.

It is worth to use broadcast to update a binding service. This way, the
binding table can be updated on all peer nodes in one shot.

Broadcast is used when all peer nodes, as indicated by a new capability
flag TIPC_NAMED_BCAST, support reception of this message type.

Four problems need to be considered when introducing this feature.
1) When establishing a link to a new peer node we still update this by a
unicast 'bulk' update. This may lead to race conditions, where a later
broadcast publication/withdrawal bypass the 'bulk', resulting in
disordered publications, or even that a withdrawal may arrive before the
corresponding publication. We solve this by adding an 'is_last_bulk' bit
in the last bulk messages so that it can be distinguished from all other
messages. Only when this message has arrived do we open up for reception
of broadcast publications/withdrawals.

2) When a first legacy node is added to the cluster all distribution
will switch over to use the legacy 'replicast' method, while the
opposite happens when the last legacy node leaves the cluster. This
entails another risk of message disordering that has to be handled. We
solve this by adding a sequence number to the broadcast/replicast
messages, so that disordering can be discovered and corrected. Note
however that we don't need to consider potential message loss or
duplication at this protocol level.

3) Bulk messages don't contain any sequence numbers, and will always
arrive in order. Hence we must exempt those from the sequence number
control and deliver them unconditionally. We solve this by adding a new
'is_bulk' bit in those messages so that they can be recognized.

4) Legacy messages, which don't contain any new bits or sequence
numbers, but neither can arrive out of order, also need to be exempt
from the initial synchronization and sequence number check, and
delivered unconditionally. Therefore, we add another 'is_not_legacy' bit
to all new messages so that those can be distinguished from legacy
messages and the latter delivered directly.

v1->v2:
 - fix warning issue reported by kbuild test robot <lkp@intel.com>
 - add santiy check to drop the publication message with a sequence
number that is lower than the agreed synch point
Signed-off-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NHoang Huu Le <hoang.h.le@dektech.com.au>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit de058420.

There is no actual tipc_node refcnt leak as stated in the above commit.
The refcnt is hold carefully for the case of an asynchronous decryption
(i.e. -EINPROGRESS/-EBUSY and skb = NULL is returned), so that the node
object cannot be freed in the meantime. The counter will be re-balanced
when the operation's callback arrives with the decrypted buffer if any.
In other cases, e.g. a synchronous crypto the counter will be decreased
immediately when it is done.

Now with that commit, a kernel panic will occur when there is no node
found (i.e. n = NULL) in the 'tipc_rcv()' or a premature release of the
node object.

This commit solves the issues by reverting the said commit, but keeping
one valid case that the 'skb_linearize()' is failed.
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Tested-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit enables dumping the statistics of a broadcast-receiver link
like the traditional 'broadcast-link' one (which is for broadcast-
sender). The link dumping can be triggered via netlink (e.g. the
iproute2/tipc tool) by the link flag - 'TIPC_NLA_LINK_BROADCAST' as the
indicator.

The name of a broadcast-receiver link of a specific peer will be in the
format: 'broadcast-link:<peer-id>'.

For example:

Link <broadcast-link:1001002>
  Window:50 packets
  RX packets:7841 fragments:2408/440 bundles:0/0
  TX packets:0 fragments:0/0 bundles:0/0
  RX naks:0 defs:124 dups:0
  TX naks:21 acks:0 retrans:0
  Congestion link:0  Send queue max:0 avg:0

In addition, the broadcast-receiver link statistics can be reset in the
usual way via netlink by specifying that link name in command.

Note: the 'tipc_link_name_ext()' is removed because the link name can
now be retrieved simply via the 'l->name'.
Acked-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In some environment, broadcast traffic is suppressed at high rate (i.e.
a kind of bandwidth limit setting). When it is applied, TIPC broadcast
can still run successfully. However, when it comes to a high load, some
packets will be dropped first and TIPC tries to retransmit them but the
packet retransmission is intentionally broadcast too, so making things
worse and not helpful at all.

This commit enables the broadcast retransmission via unicast which only
retransmits packets to the specific peer that has really reported a gap
i.e. not broadcasting to all nodes in the cluster, so will prevent from
being suppressed, and also reduce some overheads on the other peers due
to duplicates, finally improve the overall TIPC broadcast performance.

Note: the functionality can be turned on/off via the sysctl file:

echo 1 > /proc/sys/net/tipc/bc_retruni
echo 0 > /proc/sys/net/tipc/bc_retruni

Default is '0', i.e. the broadcast retransmission still works as usual.
Acked-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As achieved through commit 9195948f ("tipc: improve TIPC throughput
by Gap ACK blocks"), we apply the same mechanism for the broadcast link
as well. The 'Gap ACK blocks' data field in a 'PROTOCOL/STATE_MSG' will
consist of two parts built for both the broadcast and unicast types:

 31                       16 15                        0
+-------------+-------------+-------------+-------------+
|  bgack_cnt  |  ugack_cnt  |            len            |
+-------------+-------------+-------------+-------------+  -
|            gap            |            ack            |   |
+-------------+-------------+-------------+-------------+    > bc gacks
:                           :                           :   |
+-------------+-------------+-------------+-------------+  -
|            gap            |            ack            |   |
+-------------+-------------+-------------+-------------+    > uc gacks
:                           :                           :   |
+-------------+-------------+-------------+-------------+  -

which is "automatically" backward-compatible.

We also increase the max number of Gap ACK blocks to 128, allowing upto
64 blocks per type (total buffer size = 516 bytes).

Besides, the 'tipc_link_advance_transmq()' function is refactored which
is applicable for both the unicast and broadcast cases now, so some old
functions can be removed and the code is optimized.

With the patch, TIPC broadcast is more robust regardless of packet loss
or disorder, latency, ... in the underlying network. Its performance is
boost up significantly.
For example, experiment with a 5% packet loss rate results:

$ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000
real    0m 42.46s
user    0m 1.16s
sys     0m 17.67s

Without the patch:

$ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000
real    8m 27.94s
user    0m 0.55s
sys     0m 2.38s
Acked-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tipc_rcv() invokes tipc_node_find() twice, which returns a reference of
the specified tipc_node object to "n" with increased refcnt.

When tipc_rcv() returns or a new object is assigned to "n", the original
local reference of "n" becomes invalid, so the refcount should be
decreased to keep refcount balanced.

The issue happens in some paths of tipc_rcv(), which forget to decrease
the refcnt increased by tipc_node_find() and will cause a refcnt leak.

Fix this issue by calling tipc_node_put() before the original object
pointed by "n" becomes invalid.
Signed-off-by: NXiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: NXin Tan <tanxin.ctf@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the commit f73b1281
("tipc: improve throughput between nodes in netns"), we're missing a check
to handle TIPC_DIRECT_MSG type, it's still using old sending mechanism for
this message type. So, throughput improvement is not significant as
expected.

Besides that, when sending a large message with that type, we're also
handle wrong receiving queue, it should be enqueued in socket receiving
instead of multicast messages.

Fix this by adding the missing case for TIPC_DIRECT_MSG.

Fixes: f73b1281 ("tipc: improve throughput between nodes in netns")
Reported-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the following sparse warning:

net/tipc/node.c:281:6: warning: symbol 'tipc_node_free' was not declared. Should it be static?
net/tipc/node.c:2801:5: warning: symbol '__tipc_nl_node_set_key' was not declared. Should it be static?
net/tipc/node.c:2878:5: warning: symbol '__tipc_nl_node_flush_key' was not declared. Should it be static?

Fixes: fc1b6d6d ("tipc: introduce TIPC encryption & authentication")
Fixes: e1f32190 ("tipc: add support for AEAD key setting via netlink")
Signed-off-by: NChen Wandun <chenwandun@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We introduce a simple variable window congestion control for links.
The algorithm is inspired by the Reno algorithm, covering both 'slow
start', 'congestion avoidance', and 'fast recovery' modes.

- We introduce hard lower and upper window limits per link, still
  different and configurable per bearer type.

- We introduce a 'slow start theshold' variable, initially set to
  the maximum window size.

- We let a link start at the minimum congestion window, i.e. in slow
  start mode, and then let is grow rapidly (+1 per rceived ACK) until
  it reaches the slow start threshold and enters congestion avoidance
  mode.

- In congestion avoidance mode we increment the congestion window for
  each window-size number of acked packets, up to a possible maximum
  equal to the configured maximum window.

- For each non-duplicate NACK received, we drop back to fast recovery
  mode, by setting the both the slow start threshold to and the
  congestion window to (current_congestion_window / 2).

- If the timeout handler finds that the transmit queue has not moved
  since the previous timeout, it drops the link back to slow start
  and forces a probe containing the last sent sequence number to the
  sent to the peer, so that this can discover the stale situation.

This change does in reality have effect only on unicast ethernet
transport, as we have seen that there is no room whatsoever for
increasing the window max size for the UDP bearer.
For now, we also choose to keep the limits for the broadcast link
unchanged and equal.

This algorithm seems to give a 50-100% throughput improvement for
messages larger than MTU.
Suggested-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When setting up a cluster with non-replicast/replicast capability
supported. This capability will be disabled for broadcast send link
in order to be backwards compatible.

However, when these non-support nodes left and be removed out the cluster.
We don't update this capability on broadcast send link. Then, some of
features that based on this capability will also disabling as unexpected.

In this commit, we make sure the broadcast send link capabilities will
be re-calculated as soon as a node removed/rejoined a cluster.
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit adds two netlink commands to TIPC in order for user to be
able to set or remove AEAD keys:
- TIPC_NL_KEY_SET
- TIPC_NL_KEY_FLUSH

When the 'KEY_SET' is given along with the key data, the key will be
initiated and attached to TIPC crypto. On the other hand, the
'KEY_FLUSH' command will remove all existing keys if any.
Acked-by: NYing Xue <ying.xue@windreiver.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit offers an option to encrypt and authenticate all messaging,
including the neighbor discovery messages. The currently most advanced
algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All
encryption/decryption is done at the bearer layer, just before leaving
or after entering TIPC.

Supported features:
- Encryption & authentication of all TIPC messages (header + data);
- Two symmetric-key modes: Cluster and Per-node;
- Automatic key switching;
- Key-expired revoking (sequence number wrapped);
- Lock-free encryption/decryption (RCU);
- Asynchronous crypto, Intel AES-NI supported;
- Multiple cipher transforms;
- Logs & statistics;

Two key modes:
- Cluster key mode: One single key is used for both TX & RX in all
nodes in the cluster.
- Per-node key mode: Each nodes in the cluster has one specific TX key.
For RX, a node requires its peers' TX key to be able to decrypt the
messages from those peers.

Key setting from user-space is performed via netlink by a user program
(e.g. the iproute2 'tipc' tool).

Internal key state machine:

                                 Attach    Align(RX)
                                     +-+   +-+
                                     | V   | V
        +---------+      Attach     +---------+
        |  IDLE   |---------------->| PENDING |(user = 0)
        +---------+                 +---------+
           A   A                   Switch|  A
           |   |                         |  |
           |   | Free(switch/revoked)    |  |
     (Free)|   +----------------------+  |  |Timeout
           |              (TX)        |  |  |(RX)
           |                          |  |  |
           |                          |  v  |
        +---------+      Switch     +---------+
        | PASSIVE |<----------------| ACTIVE  |
        +---------+       (RX)      +---------+
        (user = 1)                  (user >= 1)

The number of TFMs is 10 by default and can be changed via the procfs
'net/tipc/max_tfms'. At this moment, as for simplicity, this file is
also used to print the crypto statistics at runtime:

echo 0xfff1 > /proc/sys/net/tipc/max_tfms

The patch defines a new TIPC version (v7) for the encryption message (-
backward compatibility as well). The message is basically encapsulated
as follows:

   +----------------------------------------------------------+
   | TIPCv7 encryption  | Original TIPCv2    | Authentication |
   | header             | packet (encrypted) | Tag            |
   +----------------------------------------------------------+

The throughput is about ~40% for small messages (compared with non-
encryption) and ~9% for large messages. With the support from hardware
crypto i.e. the Intel AES-NI CPU instructions, the throughput increases
upto ~85% for small messages and ~55% for large messages.

By default, the new feature is inactive (i.e. no encryption) until user
sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO"
in the kernel configuration to enable/disable the new code when needed.

MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc
Acked-by: NYing Xue <ying.xue@windreiver.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When user sets RX key for a peer not existing on the own node, a new
node entry is needed to which the RX key will be attached. However,
since the peer node address (& capabilities) is unknown at that moment,
only the node-ID is provided, this commit allows the creation of a node
with only the data that we call as “preliminary”.

A preliminary node is not the object of the “tipc_node_find()” but the
“tipc_node_find_by_id()”. Once the first message i.e. LINK_CONFIG comes
from that peer, and is successfully decrypted by the own node, the
actual peer node data will be properly updated and the node will
function as usual.

In addition, the node timer always starts when a node object is created
so if a preliminary node is not used, it will be cleaned up.

The later encryption functions will also use the node timer and be able
to create a preliminary node automatically when needed.
Acked-by: NYing Xue <ying.xue@windreiver.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, we scan over all network namespaces at each received
discovery message in order to check if the sending peer might be
present in a host local namespaces.

This is unnecessary since we can assume that a peer will not change its
location during an established session.

We now improve the condition for this testing so that we don't perform
any redundant scans.

Fixes: f73b1281 ("tipc: improve throughput between nodes in netns")
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two improvements when re-calculate cluster capabilities:

- When deleting a specific down node, need to re-calculate.
- In tipc_node_cleanup(), do not need to re-calculate if node
is still existing in cluster.
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Acked-by: Jon
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, TIPC transports intra-node user data messages directly
socket to socket, hence shortcutting all the lower layers of the
communication stack. This gives TIPC very good intra node performance,
both regarding throughput and latency.

We now introduce a similar mechanism for TIPC data traffic across
network namespaces located in the same kernel. On the send path, the
call chain is as always accompanied by the sending node's network name
space pointer. However, once we have reliably established that the
receiving node is represented by a namespace on the same host, we just
replace the namespace pointer with the receiving node/namespace's
ditto, and follow the regular socket receive patch though the receiving
node. This technique gives us a throughput similar to the node internal
throughput, several times larger than if we let the traffic go though
the full network stacks. As a comparison, max throughput for 64k
messages is four times larger than TCP throughput for the same type of
traffic.

To meet any security concerns, the following should be noted.

- All nodes joining a cluster are supposed to have been be certified
and authenticated by mechanisms outside TIPC. This is no different for
nodes/namespaces on the same host; they have to auto discover each
other using the attached interfaces, and establish links which are
supervised via the regular link monitoring mechanism. Hence, a kernel
local node has no other way to join a cluster than any other node, and
have to obey to policies set in the IP or device layers of the stack.

- Only when a sender has established with 100% certainty that the peer
node is located in a kernel local namespace does it choose to let user
data messages, and only those, take the crossover path to the receiving
node/namespace.

- If the receiving node/namespace is removed, its namespace pointer
is invalidated at all peer nodes, and their neighbor link monitoring
will eventually note that this node is gone.

- To ensure the "100% certainty" criteria, and prevent any possible
spoofing, received discovery messages must contain a proof that the
sender knows a common secret. We use the hash mix of the sending
node/namespace for this purpose, since it can be accessed directly by
all other namespaces in the kernel. Upon reception of a discovery
message, the receiver checks this proof against all the local
namespaces'hash_mix:es. If it finds a match, that, along with a
matching node id and cluster id, this is deemed sufficient proof that
the peer node in question is in a local namespace, and a wormhole can
be opened.

- We should also consider that TIPC is intended to be a cluster local
IPC mechanism (just like e.g. UNIX sockets) rather than a network
protocol, and hence we think it can justified to allow it to shortcut the
lower protocol layers.

Regarding traceability, we should notice that since commit 6c9081a3
("tipc: add loopback device tracking") it is possible to follow the node
internal packet flow by just activating tcpdump on the loopback
interface. This will be true even for this mechanism; by activating
tcpdump on the involved nodes' loopback interfaces their inter-name
space messaging can easily be tracked.

v2:
- update 'net' pointer when node left/rejoined
v3:
- grab read/write lock when using node ref obj
v4:
- clone traffics between netns to loopback
Suggested-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>