linux-toradex.git/net/tipc/core.c, branch v5.5

tipc: fix ordering of tipc module init and exit routine

2019-12-06T20:01:09+00:00

In order to set/get/dump, the tipc uses the generic netlink
infrastructure. So, when tipc module is inserted, init function
calls genl_register_family().
After genl_register_family(), set/get/dump commands are immediately
allowed and these callbacks internally use the net_generic.
net_generic is allocated by register_pernet_device() but this
is called after genl_register_family() in the __init function.
So, these callbacks would use un-initialized net_generic.

Test commands:
    #SHELL1
    while :
    do
        modprobe tipc
        modprobe -rv tipc
    done

    #SHELL2
    while :
    do
        tipc link list
    done

Splat looks like:
[   59.616322][ T2788] kasan: CONFIG_KASAN_INLINE enabled
[   59.617234][ T2788] kasan: GPF could be caused by NULL-ptr deref or user memory access
[   59.618398][ T2788] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[   59.619389][ T2788] CPU: 3 PID: 2788 Comm: tipc Not tainted 5.4.0+ #194
[   59.620231][ T2788] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   59.621428][ T2788] RIP: 0010:tipc_bcast_get_broadcast_mode+0x131/0x310 [tipc]
[   59.622379][ T2788] Code: c7 c6 ef 8b 38 c0 65 ff 0d 84 83 c9 3f e8 d7 a5 f2 e3 48 8d bb 38 11 00 00 48 b8 00 00 00 00
[   59.622550][ T2780] NET: Registered protocol family 30
[   59.624627][ T2788] RSP: 0018:ffff88804b09f578 EFLAGS: 00010202
[   59.624630][ T2788] RAX: dffffc0000000000 RBX: 0000000000000011 RCX: 000000008bc66907
[   59.624631][ T2788] RDX: 0000000000000229 RSI: 000000004b3cf4cc RDI: 0000000000001149
[   59.624633][ T2788] RBP: ffff88804b09f588 R08: 0000000000000003 R09: fffffbfff4fb3df1
[   59.624635][ T2788] R10: fffffbfff50318f8 R11: ffff888066cadc18 R12: ffffffffa6cc2f40
[   59.624637][ T2788] R13: 1ffff11009613eba R14: ffff8880662e9328 R15: ffff8880662e9328
[   59.624639][ T2788] FS:  00007f57d8f7b740(0000) GS:ffff88806cc00000(0000) knlGS:0000000000000000
[   59.624645][ T2788] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.625875][ T2780] tipc: Started in single node mode
[   59.626128][ T2788] CR2: 00007f57d887a8c0 CR3: 000000004b140002 CR4: 00000000000606e0
[   59.633991][ T2788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   59.635195][ T2788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   59.636478][ T2788] Call Trace:
[   59.637025][ T2788]  tipc_nl_add_bc_link+0x179/0x1470 [tipc]
[   59.638219][ T2788]  ? lock_downgrade+0x6e0/0x6e0
[   59.638923][ T2788]  ? __tipc_nl_add_link+0xf90/0xf90 [tipc]
[   59.639533][ T2788]  ? tipc_nl_node_dump_link+0x318/0xa50 [tipc]
[   59.640160][ T2788]  ? mutex_lock_io_nested+0x1380/0x1380
[   59.640746][ T2788]  tipc_nl_node_dump_link+0x4fd/0xa50 [tipc]
[   59.641356][ T2788]  ? tipc_nl_node_reset_link_stats+0x340/0x340 [tipc]
[   59.642088][ T2788]  ? __skb_ext_del+0x270/0x270
[   59.642594][ T2788]  genl_lock_dumpit+0x85/0xb0
[   59.643050][ T2788]  netlink_dump+0x49c/0xed0
[   59.643529][ T2788]  ? __netlink_sendskb+0xc0/0xc0
[   59.644044][ T2788]  ? __netlink_dump_start+0x190/0x800
[   59.644617][ T2788]  ? __mutex_unlock_slowpath+0xd0/0x670
[   59.645177][ T2788]  __netlink_dump_start+0x5a0/0x800
[   59.645692][ T2788]  genl_rcv_msg+0xa75/0xe90
[   59.646144][ T2788]  ? __lock_acquire+0xdfe/0x3de0
[   59.646692][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.647340][ T2788]  ? genl_lock_dumpit+0xb0/0xb0
[   59.647821][ T2788]  ? genl_unlock+0x20/0x20
[   59.648290][ T2788]  ? genl_parallel_done+0xe0/0xe0
[   59.648787][ T2788]  ? find_held_lock+0x39/0x1d0
[   59.649276][ T2788]  ? genl_rcv+0x15/0x40
[   59.649722][ T2788]  ? lock_contended+0xcd0/0xcd0
[   59.650296][ T2788]  netlink_rcv_skb+0x121/0x350
[   59.650828][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.651491][ T2788]  ? netlink_ack+0x940/0x940
[   59.651953][ T2788]  ? lock_acquire+0x164/0x3b0
[   59.652449][ T2788]  genl_rcv+0x24/0x40
[   59.652841][ T2788]  netlink_unicast+0x421/0x600
[ ... ]

Fixes: 7e4369057806 ("tipc: fix a slab object leak")
Fixes: a62fbccecd62 ("tipc: make subscriber server support net namespace")
Signed-off-by: Taehee Yoo 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2019-11-17T05:51:42+00:00

Lots of overlapping changes and parallel additions, stuff
like that.

Signed-off-by: David S. Miller

tipc: add back tipc prefix to log messages

2019-11-15T02:03:03+00:00

The tipc prefix for log messages generated by tipc was
removed in commit 07f6c4bc048a ("tipc: convert tipc reference
table to use generic rhashtable").

This is still a useful prefix so add it back.

Signed-off-by: Matt Bennett 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: introduce TIPC encryption & authentication

2019-11-08T22:01:59+00:00

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: Ying Xue 
Acked-by: Jon Maloy 
Signed-off-by: Tuong Lien 
Signed-off-by: David S. Miller

tipc: improve throughput between nodes in netns

2019-10-30T00:55:38+00:00

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 6c9081a3915d
("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: Jon Maloy 
Acked-by: Jon Maloy 
Signed-off-by: Hoang Le 
Signed-off-by: David S. Miller

tipc: add loopback device tracking

2019-08-09T05:11:39+00:00

Since node internal messages are passed directly to the socket, it is not
possible to observe those messages via tcpdump or wireshark.

We now remedy this by making it possible to clone such messages and send
the clones to the loopback interface.  The clones are dropped at reception
and have no functional role except making the traffic visible.

The feature is enabled if network taps are active for the loopback device.
pcap filtering restrictions require the messages to be presented to the
receiving side of the loopback device.

v3 - Function dev_nit_active used to check for network taps.
   - Procedure netif_rx_ni used to send cloned messages to loopback device.

Signed-off-by: John Rutherford 
Acked-by: Jon Maloy 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: change to use register_pernet_device

2019-06-22T23:51:47+00:00

This patch is to fix a dst defcnt leak, which can be reproduced by doing:

  # ip net a c; ip net a s; modprobe tipc
  # ip net e s ip l a n eth1 type veth peer n eth1 netns c
  # ip net e c ip l s lo up; ip net e c ip l s eth1 up
  # ip net e s ip l s lo up; ip net e s ip l s eth1 up
  # ip net e c ip a a 1.1.1.2/8 dev eth1
  # ip net e s ip a a 1.1.1.1/8 dev eth1
  # ip net e c tipc b e m udp n u1 localip 1.1.1.2
  # ip net e s tipc b e m udp n u1 localip 1.1.1.1
  # ip net d c; ip net d s; rmmod tipc

and it will get stuck and keep logging the error:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

The cause is that a dst is held by the udp sock's sk_rx_dst set on udp rx
path with udp_early_demux == 1, and this dst (eventually holding lo dev)
can't be released as bearer's removal in tipc pernet .exit happens after
lo dev's removal, default_device pernet .exit.

 "There are two distinct types of pernet_operations recognized: subsys and
  device.  At creation all subsys init functions are called before device
  init functions, and at destruction all device exit functions are called
  before subsys exit function."

So by calling register_pernet_device instead to register tipc_net_ops, the
pernet .exit() will be invoked earlier than loopback dev's removal when a
netns is being destroyed, as fou/gue does.

Note that vxlan and geneve udp tunnels don't have this issue, as the udp
sock is released in their device ndo_stop().

This fix is also necessary for tipc dst_cache, which will hold dsts on tx
path and I will introduce in my next patch.

Reported-by: Li Shuang 
Signed-off-by: Xin Long 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: fix modprobe tipc failed after switch order of device registration

2019-05-20T17:45:43+00:00

Error message printed:
modprobe: ERROR: could not insert 'tipc': Address family not
supported by protocol.
when modprobe tipc after the following patch: switch order of
device registration, commit 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")

Because sock_create_kern(net, AF_TIPC, ...) called by
tipc_topsrv_create_listener() in the initialization process
of tipc_init_net(), so tipc_socket_init() must be execute before that.
Meanwhile, tipc_net_id need to be initialized when sock_create()
called, and tipc_socket_init() is no need to be called for each namespace.

I add a variable tipc_topsrv_net_ops, and split the
register_pernet_subsys() of tipc into two parts, and split
tipc_socket_init() with initialization of pernet params.

By the way, I fixed resources rollback error when tipc_bcast_init()
failed in tipc_init_net().

Fixes: 7e27e8d6130c ("tipc: switch order of device registration to fix a crash")
Signed-off-by: Junwei Hu 
Reported-by: Wang Wang 
Reported-by: syzbot+1e8114b61079bfe9cbc5@syzkaller.appspotmail.com
Reviewed-by: Kang Zhou 
Reviewed-by: Suanming Mou 
Signed-off-by: David S. Miller

Revert "tipc: fix modprobe tipc failed after switch order of device registration"

2019-05-17T19:15:05+00:00

This reverts commit 532b0f7ece4cb2ffd24dc723ddf55242d1188e5e.

More revisions coming up.

Signed-off-by: David S. Miller

tipc: fix modprobe tipc failed after switch order of device registration

2019-05-17T18:33:51+00:00

Error message printed:
modprobe: ERROR: could not insert 'tipc': Address family not
supported by protocol.
when modprobe tipc after the following patch: switch order of
device registration, commit 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")

Because sock_create_kern(net, AF_TIPC, ...) is called by
tipc_topsrv_create_listener() in the initialization process
of tipc_net_ops, tipc_socket_init() must be execute before that.

I move tipc_socket_init() into function tipc_init_net().

Fixes: 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")
Signed-off-by: Junwei Hu 
Reported-by: Wang Wang 
Reviewed-by: Kang Zhou 
Reviewed-by: Suanming Mou 
Signed-off-by: David S. Miller