[net-next v2 0/5] TIPC Encryption

[net-next v2 0/5] TIPC Encryption

[Tuong Lien]

This series provides TIPC encryption feature, kernel part. There will be
another one in the 'iproute2/tipc' for user space to set key.

v2: add select crypto 'aes(gcm)' for TIPC_CRYPTO in Kconfig

Tuong Lien (5):
  tipc: add reference counter to bearer
  tipc: enable creating a "preliminary" node
  tipc: add new AEAD key structure for user API
  tipc: introduce TIPC encryption & authentication
  tipc: add support for AEAD key setting via netlink

 include/uapi/linux/tipc.h         |   21 +
 include/uapi/linux/tipc_netlink.h |    4 +
 net/tipc/Kconfig                  |   15 +
 net/tipc/Makefile                 |    1 +
 net/tipc/bcast.c                  |    2 +-
 net/tipc/bearer.c                 |   49 +-
 net/tipc/bearer.h                 |    6 +-
 net/tipc/core.c                   |   14 +
 net/tipc/core.h                   |    8 +
 net/tipc/crypto.c                 | 1986 +++++++++++++++++++++++++++++++++++++
 net/tipc/crypto.h                 |  167 ++++
 net/tipc/link.c                   |   19 +-
 net/tipc/link.h                   |    1 +
 net/tipc/msg.c                    |   15 +-
 net/tipc/msg.h                    |   46 +-
 net/tipc/netlink.c                |   18 +-
 net/tipc/node.c                   |  325 +++++-
 net/tipc/node.h                   |   13 +
 net/tipc/sysctl.c                 |   11 +
 net/tipc/udp_media.c              |    1 +
 20 files changed, 2651 insertions(+), 71 deletions(-)
 create mode 100644 net/tipc/crypto.c
 create mode 100644 net/tipc/crypto.h

-- 
2.13.7

[net-next v2 1/5] tipc: add reference counter to bearer

[Tuong Lien]

As a need to support the crypto asynchronous operations in the later
commits, apart from the current RCU mechanism for bearer pointer, we
add a 'refcnt' to the bearer object as well.

So, a bearer can be hold via 'tipc_bearer_hold()' without being freed
even though the bearer or interface can be disabled in the meanwhile.
If that happens, the bearer will be released then when the crypto
operation is completed and 'tipc_bearer_put()' is called.

Acked-by: Ying Xue <ying.xue@windreiver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
---
 net/tipc/bearer.c | 14 +++++++++++++-
 net/tipc/bearer.h |  3 +++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 0214aa1c4427..6e15b9b1f1ef 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -315,6 +315,7 @@ static int tipc_enable_bearer(struct net *net, const char *name,
 	b->net_plane = bearer_id + 'A';
 	b->priority = prio;
 	test_and_set_bit_lock(0, &b->up);
+	refcount_set(&b->refcnt, 1);
 
 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
 	if (res) {
@@ -351,6 +352,17 @@ static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
 	return 0;
 }
 
+bool tipc_bearer_hold(struct tipc_bearer *b)
+{
+	return (b && refcount_inc_not_zero(&b->refcnt));
+}
+
+void tipc_bearer_put(struct tipc_bearer *b)
+{
+	if (b && refcount_dec_and_test(&b->refcnt))
+		kfree_rcu(b, rcu);
+}
+
 /**
  * bearer_disable
  *
@@ -369,7 +381,7 @@ static void bearer_disable(struct net *net, struct tipc_bearer *b)
 	if (b->disc)
 		tipc_disc_delete(b->disc);
 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
-	kfree_rcu(b, rcu);
+	tipc_bearer_put(b);
 	tipc_mon_delete(net, bearer_id);
 }
 
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index ea0f3c49cbed..faca696d422f 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -165,6 +165,7 @@ struct tipc_bearer {
 	struct tipc_discoverer *disc;
 	char net_plane;
 	unsigned long up;
+	refcount_t refcnt;
 };
 
 struct tipc_bearer_names {
@@ -210,6 +211,8 @@ int tipc_media_set_window(const char *name, u32 new_value);
 int tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a);
 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
 			 struct nlattr *attrs[]);
+bool tipc_bearer_hold(struct tipc_bearer *b);
+void tipc_bearer_put(struct tipc_bearer *b);
 void tipc_disable_l2_media(struct tipc_bearer *b);
 int tipc_l2_send_msg(struct net *net, struct sk_buff *buf,
 		     struct tipc_bearer *b, struct tipc_media_addr *dest);
-- 
2.13.7

[net-next v2 2/5] tipc: enable creating a "preliminary" node

[Tuong Lien]

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: Ying Xue <ying.xue@windreiver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
---
 net/tipc/node.c | 99 +++++++++++++++++++++++++++++++++++++++++----------------
 net/tipc/node.h |  1 +
 2 files changed, 73 insertions(+), 27 deletions(-)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index b66d2f67b1dd..43d12a630f34 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -89,6 +89,7 @@ struct tipc_bclink_entry {
  * @links: array containing references to all links to node
  * @action_flags: bit mask of different types of node actions
  * @state: connectivity state vs peer node
+ * @preliminary: a preliminary node or not
  * @sync_point: sequence number where synch/failover is finished
  * @list: links to adjacent nodes in sorted list of cluster's nodes
  * @working_links: number of working links to node (both active and standby)
@@ -112,6 +113,7 @@ struct tipc_node {
 	int action_flags;
 	struct list_head list;
 	int state;
+	bool preliminary;
 	bool failover_sent;
 	u16 sync_point;
 	int link_cnt;
@@ -120,6 +122,7 @@ struct tipc_node {
 	u32 signature;
 	u32 link_id;
 	u8 peer_id[16];
+	char peer_id_string[NODE_ID_STR_LEN];
 	struct list_head publ_list;
 	struct list_head conn_sks;
 	unsigned long keepalive_intv;
@@ -245,6 +248,16 @@ u16 tipc_node_get_capabilities(struct net *net, u32 addr)
 	return caps;
 }
 
+u32 tipc_node_get_addr(struct tipc_node *node)
+{
+	return (node) ? node->addr : 0;
+}
+
+char *tipc_node_get_id_str(struct tipc_node *node)
+{
+	return node->peer_id_string;
+}
+
 static void tipc_node_kref_release(struct kref *kref)
 {
 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
@@ -274,7 +287,7 @@ static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
-		if (node->addr != addr)
+		if (node->addr != addr || node->preliminary)
 			continue;
 		if (!kref_get_unless_zero(&node->kref))
 			node = NULL;
@@ -400,17 +413,39 @@ static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
 
 static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 					  u8 *peer_id, u16 capabilities,
-					  u32 signature, u32 hash_mixes)
+					  u32 hash_mixes, bool preliminary)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_node *n, *temp_node;
 	struct tipc_link *l;
+	unsigned long intv;
 	int bearer_id;
 	int i;
 
 	spin_lock_bh(&tn->node_list_lock);
-	n = tipc_node_find(net, addr);
+	n = tipc_node_find(net, addr) ?:
+		tipc_node_find_by_id(net, peer_id);
 	if (n) {
+		if (!n->preliminary)
+			goto update;
+		if (preliminary)
+			goto exit;
+		/* A preliminary node becomes "real" now, refresh its data */
+		tipc_node_write_lock(n);
+		n->preliminary = false;
+		n->addr = addr;
+		hlist_del_rcu(&n->hash);
+		hlist_add_head_rcu(&n->hash,
+				   &tn->node_htable[tipc_hashfn(addr)]);
+		list_del_rcu(&n->list);
+		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
+			if (n->addr < temp_node->addr)
+				break;
+		}
+		list_add_tail_rcu(&n->list, &temp_node->list);
+		tipc_node_write_unlock_fast(n);
+
+update:
 		if (n->peer_hash_mix ^ hash_mixes)
 			tipc_node_assign_peer_net(n, hash_mixes);
 		if (n->capabilities == capabilities)
@@ -438,7 +473,9 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 		pr_warn("Node creation failed, no memory\n");
 		goto exit;
 	}
+	tipc_nodeid2string(n->peer_id_string, peer_id);
 	n->addr = addr;
+	n->preliminary = preliminary;
 	memcpy(&n->peer_id, peer_id, 16);
 	n->net = net;
 	n->peer_net = NULL;
@@ -463,22 +500,14 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 	n->signature = INVALID_NODE_SIG;
 	n->active_links[0] = INVALID_BEARER_ID;
 	n->active_links[1] = INVALID_BEARER_ID;
-	if (!tipc_link_bc_create(net, tipc_own_addr(net),
-				 addr, U16_MAX,
-				 tipc_link_window(tipc_bc_sndlink(net)),
-				 n->capabilities,
-				 &n->bc_entry.inputq1,
-				 &n->bc_entry.namedq,
-				 tipc_bc_sndlink(net),
-				 &n->bc_entry.link)) {
-		pr_warn("Broadcast rcv link creation failed, no memory\n");
-		kfree(n);
-		n = NULL;
-		goto exit;
-	}
+	n->bc_entry.link = NULL;
 	tipc_node_get(n);
 	timer_setup(&n->timer, tipc_node_timeout, 0);
-	n->keepalive_intv = U32_MAX;
+	/* Start a slow timer anyway, crypto needs it */
+	n->keepalive_intv = 10000;
+	intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
+	if (!mod_timer(&n->timer, intv))
+		tipc_node_get(n);
 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 		if (n->addr < temp_node->addr)
@@ -1001,6 +1030,8 @@ u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
 {
 	struct tipc_net *tn = tipc_net(net);
 	struct tipc_node *n;
+	bool preliminary;
+	u32 sugg_addr;
 
 	/* Suggest new address if some other peer is using this one */
 	n = tipc_node_find(net, addr);
@@ -1016,9 +1047,11 @@ u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
 	/* Suggest previously used address if peer is known */
 	n = tipc_node_find_by_id(net, id);
 	if (n) {
-		addr = n->addr;
+		sugg_addr = n->addr;
+		preliminary = n->preliminary;
 		tipc_node_put(n);
-		return addr;
+		if (!preliminary)
+			return sugg_addr;
 	}
 
 	/* Even this node may be in conflict */
@@ -1035,7 +1068,7 @@ void tipc_node_check_dest(struct net *net, u32 addr,
 			  bool *respond, bool *dupl_addr)
 {
 	struct tipc_node *n;
-	struct tipc_link *l;
+	struct tipc_link *l, *snd_l;
 	struct tipc_link_entry *le;
 	bool addr_match = false;
 	bool sign_match = false;
@@ -1049,12 +1082,27 @@ void tipc_node_check_dest(struct net *net, u32 addr,
 	*dupl_addr = false;
 	*respond = false;
 
-	n = tipc_node_create(net, addr, peer_id, capabilities, signature,
-			     hash_mixes);
+	n = tipc_node_create(net, addr, peer_id, capabilities, hash_mixes,
+			     false);
 	if (!n)
 		return;
 
 	tipc_node_write_lock(n);
+	if (unlikely(!n->bc_entry.link)) {
+		snd_l = tipc_bc_sndlink(net);
+		if (!tipc_link_bc_create(net, tipc_own_addr(net),
+					 addr, U16_MAX,
+					 tipc_link_window(snd_l),
+					 n->capabilities,
+					 &n->bc_entry.inputq1,
+					 &n->bc_entry.namedq, snd_l,
+					 &n->bc_entry.link)) {
+			pr_warn("Broadcast rcv link creation failed, no mem\n");
+			tipc_node_write_unlock_fast(n);
+			tipc_node_put(n);
+			return;
+		}
+	}
 
 	le = &n->links[b->identity];
 
@@ -2134,6 +2182,8 @@ int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	list_for_each_entry_rcu(node, &tn->node_list, list) {
+		if (node->preliminary)
+			continue;
 		if (last_addr) {
 			if (node->addr == last_addr)
 				last_addr = 0;
@@ -2649,11 +2699,6 @@ int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
 	return skb->len;
 }
 
-u32 tipc_node_get_addr(struct tipc_node *node)
-{
-	return (node) ? node->addr : 0;
-}
-
 /**
  * tipc_node_dump - dump TIPC node data
  * @n: tipc node to be dumped
diff --git a/net/tipc/node.h b/net/tipc/node.h
index c39cd861c07d..50f8838b32c2 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -75,6 +75,7 @@ enum {
 void tipc_node_stop(struct net *net);
 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id);
 u32 tipc_node_get_addr(struct tipc_node *node);
+char *tipc_node_get_id_str(struct tipc_node *node);
 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr);
 void tipc_node_check_dest(struct net *net, u32 onode, u8 *peer_id128,
 			  struct tipc_bearer *bearer,
-- 
2.13.7

[net-next v2 3/5] tipc: add new AEAD key structure for user API

[Tuong Lien]

The new structure 'tipc_aead_key' is added to the 'tipc.h' for user to
be able to transfer a key to TIPC in kernel. Netlink will be used for
this purpose in the later commits.

Acked-by: Ying Xue <ying.xue@windreiver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
---
 include/uapi/linux/tipc.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/include/uapi/linux/tipc.h b/include/uapi/linux/tipc.h
index 76421b878767..add01db1daef 100644
--- a/include/uapi/linux/tipc.h
+++ b/include/uapi/linux/tipc.h
@@ -233,6 +233,27 @@ struct tipc_sioc_nodeid_req {
 	char node_id[TIPC_NODEID_LEN];
 };
 
+/*
+ * TIPC Crypto, AEAD
+ */
+#define TIPC_AEAD_ALG_NAME		(32)
+
+struct tipc_aead_key {
+	char alg_name[TIPC_AEAD_ALG_NAME];
+	unsigned int keylen;	/* in bytes */
+	char key[];
+};
+
+#define TIPC_AEAD_KEYLEN_MIN		(16 + 4)
+#define TIPC_AEAD_KEYLEN_MAX		(32 + 4)
+#define TIPC_AEAD_KEY_SIZE_MAX		(sizeof(struct tipc_aead_key) + \
+							TIPC_AEAD_KEYLEN_MAX)
+
+static inline int tipc_aead_key_size(struct tipc_aead_key *key)
+{
+	return sizeof(*key) + key->keylen;
+}
+
 /* The macros and functions below are deprecated:
  */
 
-- 
2.13.7

[net-next v2 4/5] tipc: introduce TIPC encryption & authentication

[Tuong Lien]

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 <ying.xue@windreiver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
---
 net/tipc/Kconfig     |   15 +
 net/tipc/Makefile    |    1 +
 net/tipc/bcast.c     |    2 +-
 net/tipc/bearer.c    |   35 +-
 net/tipc/bearer.h    |    3 +-
 net/tipc/core.c      |   14 +
 net/tipc/core.h      |    8 +
 net/tipc/crypto.c    | 1986 ++++++++++++++++++++++++++++++++++++++++++++++++++
 net/tipc/crypto.h    |  167 +++++
 net/tipc/link.c      |   19 +-
 net/tipc/link.h      |    1 +
 net/tipc/msg.c       |   15 +-
 net/tipc/msg.h       |   46 +-
 net/tipc/node.c      |   99 ++-
 net/tipc/node.h      |    8 +
 net/tipc/sysctl.c    |   11 +
 net/tipc/udp_media.c |    1 +
 17 files changed, 2385 insertions(+), 46 deletions(-)
 create mode 100644 net/tipc/crypto.c
 create mode 100644 net/tipc/crypto.h

diff --git a/net/tipc/Kconfig b/net/tipc/Kconfig
index b83e16ade4d2..716b61a701a8 100644
--- a/net/tipc/Kconfig
+++ b/net/tipc/Kconfig
@@ -35,6 +35,21 @@ config TIPC_MEDIA_UDP
 	  Saying Y here will enable support for running TIPC over IP/UDP
 	bool
 	default y
+config TIPC_CRYPTO
+	bool "TIPC encryption support"
+	depends on TIPC
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_GCM
+	help
+	  Saying Y here will enable support for TIPC encryption.
+	  All TIPC messages will be encrypted/decrypted by using the currently most
+	  advanced algorithm: AEAD AES-GCM (like IPSec or TLS) before leaving/
+	  entering the TIPC stack.
+	  Key setting from user-space is performed via netlink by a user program
+	  (e.g. the iproute2 'tipc' tool).
+	bool
+	default y
 
 config TIPC_DIAG
 	tristate "TIPC: socket monitoring interface"
diff --git a/net/tipc/Makefile b/net/tipc/Makefile
index c86aba0282af..11255e970dd4 100644
--- a/net/tipc/Makefile
+++ b/net/tipc/Makefile
@@ -16,6 +16,7 @@ CFLAGS_trace.o += -I$(src)
 tipc-$(CONFIG_TIPC_MEDIA_UDP)	+= udp_media.o
 tipc-$(CONFIG_TIPC_MEDIA_IB)	+= ib_media.o
 tipc-$(CONFIG_SYSCTL)		+= sysctl.o
+tipc-$(CONFIG_TIPC_CRYPTO)	+= crypto.o
 
 
 obj-$(CONFIG_TIPC_DIAG)	+= diag.o
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 6ef1abdd525f..f41096a759fa 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -84,7 +84,7 @@ static struct tipc_bc_base *tipc_bc_base(struct net *net)
  */
 int tipc_bcast_get_mtu(struct net *net)
 {
-	return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE;
+	return tipc_link_mss(tipc_bc_sndlink(net));
 }
 
 void tipc_bcast_disable_rcast(struct net *net)
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 6e15b9b1f1ef..d7ec26bd739d 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -44,6 +44,7 @@
 #include "netlink.h"
 #include "udp_media.h"
 #include "trace.h"
+#include "crypto.h"
 
 #define MAX_ADDR_STR 60
 
@@ -516,10 +517,15 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
 
 	rcu_read_lock();
 	b = bearer_get(net, bearer_id);
-	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr))))
-		b->media->send_msg(net, skb, b, dest);
-	else
+	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
+#ifdef CONFIG_TIPC_CRYPTO
+		tipc_crypto_xmit(net, &skb, b, dest, NULL);
+		if (skb)
+#endif
+			b->media->send_msg(net, skb, b, dest);
+	} else {
 		kfree_skb(skb);
+	}
 	rcu_read_unlock();
 }
 
@@ -527,7 +533,8 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
  */
 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 		      struct sk_buff_head *xmitq,
-		      struct tipc_media_addr *dst)
+		      struct tipc_media_addr *dst,
+		      struct tipc_node *__dnode)
 {
 	struct tipc_bearer *b;
 	struct sk_buff *skb, *tmp;
@@ -541,10 +548,15 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 		__skb_queue_purge(xmitq);
 	skb_queue_walk_safe(xmitq, skb, tmp) {
 		__skb_dequeue(xmitq);
-		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb))))
-			b->media->send_msg(net, skb, b, dst);
-		else
+		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
+#ifdef CONFIG_TIPC_CRYPTO
+			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
+			if (skb)
+#endif
+				b->media->send_msg(net, skb, b, dst);
+		} else {
 			kfree_skb(skb);
+		}
 	}
 	rcu_read_unlock();
 }
@@ -555,6 +567,7 @@ void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
 			 struct sk_buff_head *xmitq)
 {
 	struct tipc_net *tn = tipc_net(net);
+	struct tipc_media_addr *dst;
 	int net_id = tn->net_id;
 	struct tipc_bearer *b;
 	struct sk_buff *skb, *tmp;
@@ -569,7 +582,12 @@ void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
 		msg_set_non_seq(hdr, 1);
 		msg_set_mc_netid(hdr, net_id);
 		__skb_dequeue(xmitq);
-		b->media->send_msg(net, skb, b, &b->bcast_addr);
+		dst = &b->bcast_addr;
+#ifdef CONFIG_TIPC_CRYPTO
+		tipc_crypto_xmit(net, &skb, b, dst, NULL);
+		if (skb)
+#endif
+			b->media->send_msg(net, skb, b, dst);
 	}
 	rcu_read_unlock();
 }
@@ -596,6 +614,7 @@ static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
 	if (likely(b && test_bit(0, &b->up) &&
 		   (skb->pkt_type <= PACKET_MULTICAST))) {
 		skb_mark_not_on_list(skb);
+		TIPC_SKB_CB(skb)->flags = 0;
 		tipc_rcv(dev_net(b->pt.dev), skb, b);
 		rcu_read_unlock();
 		return NET_RX_SUCCESS;
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index faca696d422f..d0c79cc6c0c2 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -232,7 +232,8 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
 			  struct tipc_media_addr *dest);
 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 		      struct sk_buff_head *xmitq,
-		      struct tipc_media_addr *dst);
+		      struct tipc_media_addr *dst,
+		      struct tipc_node *__dnode);
 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
 			 struct sk_buff_head *xmitq);
 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts);
diff --git a/net/tipc/core.c b/net/tipc/core.c
index ab648dd150ee..fc01a13d7462 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -44,6 +44,7 @@
 #include "socket.h"
 #include "bcast.h"
 #include "node.h"
+#include "crypto.h"
 
 #include <linux/module.h>
 
@@ -68,6 +69,11 @@ static int __net_init tipc_init_net(struct net *net)
 	INIT_LIST_HEAD(&tn->node_list);
 	spin_lock_init(&tn->node_list_lock);
 
+#ifdef CONFIG_TIPC_CRYPTO
+	err = tipc_crypto_start(&tn->crypto_tx, net, NULL);
+	if (err)
+		goto out_crypto;
+#endif
 	err = tipc_sk_rht_init(net);
 	if (err)
 		goto out_sk_rht;
@@ -93,6 +99,11 @@ static int __net_init tipc_init_net(struct net *net)
 out_nametbl:
 	tipc_sk_rht_destroy(net);
 out_sk_rht:
+
+#ifdef CONFIG_TIPC_CRYPTO
+	tipc_crypto_stop(&tn->crypto_tx);
+out_crypto:
+#endif
 	return err;
 }
 
@@ -103,6 +114,9 @@ static void __net_exit tipc_exit_net(struct net *net)
 	tipc_bcast_stop(net);
 	tipc_nametbl_stop(net);
 	tipc_sk_rht_destroy(net);
+#ifdef CONFIG_TIPC_CRYPTO
+	tipc_crypto_stop(&tipc_net(net)->crypto_tx);
+#endif
 }
 
 static void __net_exit tipc_pernet_pre_exit(struct net *net)
diff --git a/net/tipc/core.h b/net/tipc/core.h
index 8776d32a4a47..775848a5f27e 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -68,6 +68,9 @@ struct tipc_link;
 struct tipc_name_table;
 struct tipc_topsrv;
 struct tipc_monitor;
+#ifdef CONFIG_TIPC_CRYPTO
+struct tipc_crypto;
+#endif
 
 #define TIPC_MOD_VER "2.0.0"
 
@@ -129,6 +132,11 @@ struct tipc_net {
 
 	/* Tracing of node internal messages */
 	struct packet_type loopback_pt;
+
+#ifdef CONFIG_TIPC_CRYPTO
+	/* TX crypto handler */
+	struct tipc_crypto *crypto_tx;
+#endif
 };
 
 static inline struct tipc_net *tipc_net(struct net *net)
diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
new file mode 100644
index 000000000000..05f7ca76e8ce
--- /dev/null
+++ b/net/tipc/crypto.c
@@ -0,0 +1,1986 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * net/tipc/crypto.c: TIPC crypto for key handling & packet en/decryption
+ *
+ * Copyright (c) 2019, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <crypto/aead.h>
+#include <crypto/aes.h>
+#include "crypto.h"
+
+#define TIPC_TX_PROBE_LIM	msecs_to_jiffies(1000) /* > 1s */
+#define TIPC_TX_LASTING_LIM	msecs_to_jiffies(120000) /* 2 mins */
+#define TIPC_RX_ACTIVE_LIM	msecs_to_jiffies(3000) /* 3s */
+#define TIPC_RX_PASSIVE_LIM	msecs_to_jiffies(180000) /* 3 mins */
+#define TIPC_MAX_TFMS_DEF	10
+#define TIPC_MAX_TFMS_LIM	1000
+
+/**
+ * TIPC Key ids
+ */
+enum {
+	KEY_UNUSED = 0,
+	KEY_MIN,
+	KEY_1 = KEY_MIN,
+	KEY_2,
+	KEY_3,
+	KEY_MAX = KEY_3,
+};
+
+/**
+ * TIPC Crypto statistics
+ */
+enum {
+	STAT_OK,
+	STAT_NOK,
+	STAT_ASYNC,
+	STAT_ASYNC_OK,
+	STAT_ASYNC_NOK,
+	STAT_BADKEYS, /* tx only */
+	STAT_BADMSGS = STAT_BADKEYS, /* rx only */
+	STAT_NOKEYS,
+	STAT_SWITCHES,
+
+	MAX_STATS,
+};
+
+/* TIPC crypto statistics' header */
+static const char *hstats[MAX_STATS] = {"ok", "nok", "async", "async_ok",
+					"async_nok", "badmsgs", "nokeys",
+					"switches"};
+
+/* Max TFMs number per key */
+int sysctl_tipc_max_tfms __read_mostly = TIPC_MAX_TFMS_DEF;
+
+/**
+ * struct tipc_key - TIPC keys' status indicator
+ *
+ *         7     6     5     4     3     2     1     0
+ *      +-----+-----+-----+-----+-----+-----+-----+-----+
+ * key: | (reserved)|passive idx| active idx|pending idx|
+ *      +-----+-----+-----+-----+-----+-----+-----+-----+
+ */
+struct tipc_key {
+#define KEY_BITS (2)
+#define KEY_MASK ((1 << KEY_BITS) - 1)
+	union {
+		struct {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+			u8 pending:2,
+			   active:2,
+			   passive:2, /* rx only */
+			   reserved:2;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+			u8 reserved:2,
+			   passive:2, /* rx only */
+			   active:2,
+			   pending:2;
+#else
+#error  "Please fix <asm/byteorder.h>"
+#endif
+		} __packed;
+		u8 keys;
+	};
+};
+
+/**
+ * struct tipc_tfm - TIPC TFM structure to form a list of TFMs
+ */
+struct tipc_tfm {
+	struct crypto_aead *tfm;
+	struct list_head list;
+};
+
+/**
+ * struct tipc_aead - TIPC AEAD key structure
+ * @tfm_entry: per-cpu pointer to one entry in TFM list
+ * @crypto: TIPC crypto owns this key
+ * @cloned: reference to the source key in case cloning
+ * @users: the number of the key users (TX/RX)
+ * @salt: the key's SALT value
+ * @authsize: authentication tag size (max = 16)
+ * @mode: crypto mode is applied to the key
+ * @hint[]: a hint for user key
+ * @rcu: struct rcu_head
+ * @seqno: the key seqno (cluster scope)
+ * @refcnt: the key reference counter
+ */
+struct tipc_aead {
+#define TIPC_AEAD_HINT_LEN (5)
+	struct tipc_tfm * __percpu *tfm_entry;
+	struct tipc_crypto *crypto;
+	struct tipc_aead *cloned;
+	atomic_t users;
+	u32 salt;
+	u8 authsize;
+	u8 mode;
+	char hint[TIPC_AEAD_HINT_LEN + 1];
+	struct rcu_head rcu;
+
+	atomic64_t seqno ____cacheline_aligned;
+	refcount_t refcnt ____cacheline_aligned;
+
+} ____cacheline_aligned;
+
+/**
+ * struct tipc_crypto_stats - TIPC Crypto statistics
+ */
+struct tipc_crypto_stats {
+	unsigned int stat[MAX_STATS];
+};
+
+/**
+ * struct tipc_crypto - TIPC TX/RX crypto structure
+ * @net: struct net
+ * @node: TIPC node (RX)
+ * @aead: array of pointers to AEAD keys for encryption/decryption
+ * @peer_rx_active: replicated peer RX active key index
+ * @key: the key states
+ * @working: the crypto is working or not
+ * @stats: the crypto statistics
+ * @sndnxt: the per-peer sndnxt (TX)
+ * @timer1: general timer 1 (jiffies)
+ * @timer2: general timer 1 (jiffies)
+ * @lock: tipc_key lock
+ */
+struct tipc_crypto {
+	struct net *net;
+	struct tipc_node *node;
+	struct tipc_aead __rcu *aead[KEY_MAX + 1]; /* key[0] is UNUSED */
+	atomic_t peer_rx_active;
+	struct tipc_key key;
+	u8 working:1;
+	struct tipc_crypto_stats __percpu *stats;
+
+	atomic64_t sndnxt ____cacheline_aligned;
+	unsigned long timer1;
+	unsigned long timer2;
+	spinlock_t lock; /* crypto lock */
+
+} ____cacheline_aligned;
+
+/* struct tipc_crypto_tx_ctx - TX context for callbacks */
+struct tipc_crypto_tx_ctx {
+	struct tipc_aead *aead;
+	struct tipc_bearer *bearer;
+	struct tipc_media_addr dst;
+};
+
+/* struct tipc_crypto_rx_ctx - RX context for callbacks */
+struct tipc_crypto_rx_ctx {
+	struct tipc_aead *aead;
+	struct tipc_bearer *bearer;
+};
+
+static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead);
+static inline void tipc_aead_put(struct tipc_aead *aead);
+static void tipc_aead_free(struct rcu_head *rp);
+static int tipc_aead_users(struct tipc_aead __rcu *aead);
+static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim);
+static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim);
+static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val);
+static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead);
+static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
+			  u8 mode);
+static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src);
+static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
+				 unsigned int crypto_ctx_size,
+				 u8 **iv, struct aead_request **req,
+				 struct scatterlist **sg, int nsg);
+static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
+			     struct tipc_bearer *b,
+			     struct tipc_media_addr *dst,
+			     struct tipc_node *__dnode);
+static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err);
+static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
+			     struct sk_buff *skb, struct tipc_bearer *b);
+static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err);
+static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr);
+static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
+			   u8 tx_key, struct sk_buff *skb,
+			   struct tipc_crypto *__rx);
+static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
+					     u8 new_passive,
+					     u8 new_active,
+					     u8 new_pending);
+static int tipc_crypto_key_attach(struct tipc_crypto *c,
+				  struct tipc_aead *aead, u8 pos);
+static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending);
+static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
+						 struct tipc_crypto *rx,
+						 struct sk_buff *skb);
+static void tipc_crypto_key_synch(struct tipc_crypto *rx, u8 new_rx_active,
+				  struct tipc_msg *hdr);
+static int tipc_crypto_key_revoke(struct net *net, u8 tx_key);
+static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
+				     struct tipc_bearer *b,
+				     struct sk_buff **skb, int err);
+static void tipc_crypto_do_cmd(struct net *net, int cmd);
+static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf);
+#ifdef TIPC_CRYPTO_DEBUG
+static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
+				  char *buf);
+#endif
+
+#define key_next(cur) ((cur) % KEY_MAX + 1)
+
+#define tipc_aead_rcu_ptr(rcu_ptr, lock)				\
+	rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock))
+
+#define tipc_aead_rcu_swap(rcu_ptr, ptr, lock)				\
+	rcu_swap_protected((rcu_ptr), (ptr), lockdep_is_held(lock))
+
+#define tipc_aead_rcu_replace(rcu_ptr, ptr, lock)			\
+do {									\
+	typeof(rcu_ptr) __tmp = rcu_dereference_protected((rcu_ptr),	\
+						lockdep_is_held(lock));	\
+	rcu_assign_pointer((rcu_ptr), (ptr));				\
+	tipc_aead_put(__tmp);						\
+} while (0)
+
+#define tipc_crypto_key_detach(rcu_ptr, lock)				\
+	tipc_aead_rcu_replace((rcu_ptr), NULL, lock)
+
+/**
+ * tipc_aead_key_validate - Validate a AEAD user key
+ */
+int tipc_aead_key_validate(struct tipc_aead_key *ukey)
+{
+	int keylen;
+
+	/* Check if algorithm exists */
+	if (unlikely(!crypto_has_alg(ukey->alg_name, 0, 0))) {
+		pr_info("Not found cipher: \"%s\"!\n", ukey->alg_name);
+		return -ENODEV;
+	}
+
+	/* Currently, we only support the "gcm(aes)" cipher algorithm */
+	if (strcmp(ukey->alg_name, "gcm(aes)"))
+		return -ENOTSUPP;
+
+	/* Check if key size is correct */
+	keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
+	if (unlikely(keylen != TIPC_AES_GCM_KEY_SIZE_128 &&
+		     keylen != TIPC_AES_GCM_KEY_SIZE_192 &&
+		     keylen != TIPC_AES_GCM_KEY_SIZE_256))
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead)
+{
+	struct tipc_aead *tmp;
+
+	rcu_read_lock();
+	tmp = rcu_dereference(aead);
+	if (unlikely(!tmp || !refcount_inc_not_zero(&tmp->refcnt)))
+		tmp = NULL;
+	rcu_read_unlock();
+
+	return tmp;
+}
+
+static inline void tipc_aead_put(struct tipc_aead *aead)
+{
+	if (aead && refcount_dec_and_test(&aead->refcnt))
+		call_rcu(&aead->rcu, tipc_aead_free);
+}
+
+/**
+ * tipc_aead_free - Release AEAD key incl. all the TFMs in the list
+ * @rp: rcu head pointer
+ */
+static void tipc_aead_free(struct rcu_head *rp)
+{
+	struct tipc_aead *aead = container_of(rp, struct tipc_aead, rcu);
+	struct tipc_tfm *tfm_entry, *head, *tmp;
+
+	if (aead->cloned) {
+		tipc_aead_put(aead->cloned);
+	} else {
+		head = *this_cpu_ptr(aead->tfm_entry);
+		list_for_each_entry_safe(tfm_entry, tmp, &head->list, list) {
+			crypto_free_aead(tfm_entry->tfm);
+			list_del(&tfm_entry->list);
+			kfree(tfm_entry);
+		}
+		/* Free the head */
+		crypto_free_aead(head->tfm);
+		list_del(&head->list);
+		kfree(head);
+	}
+	free_percpu(aead->tfm_entry);
+	kfree(aead);
+}
+
+static int tipc_aead_users(struct tipc_aead __rcu *aead)
+{
+	struct tipc_aead *tmp;
+	int users = 0;
+
+	rcu_read_lock();
+	tmp = rcu_dereference(aead);
+	if (tmp)
+		users = atomic_read(&tmp->users);
+	rcu_read_unlock();
+
+	return users;
+}
+
+static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim)
+{
+	struct tipc_aead *tmp;
+
+	rcu_read_lock();
+	tmp = rcu_dereference(aead);
+	if (tmp)
+		atomic_add_unless(&tmp->users, 1, lim);
+	rcu_read_unlock();
+}
+
+static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim)
+{
+	struct tipc_aead *tmp;
+
+	rcu_read_lock();
+	tmp = rcu_dereference(aead);
+	if (tmp)
+		atomic_add_unless(&rcu_dereference(aead)->users, -1, lim);
+	rcu_read_unlock();
+}
+
+static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val)
+{
+	struct tipc_aead *tmp;
+	int cur;
+
+	rcu_read_lock();
+	tmp = rcu_dereference(aead);
+	if (tmp) {
+		do {
+			cur = atomic_read(&tmp->users);
+			if (cur == val)
+				break;
+		} while (atomic_cmpxchg(&tmp->users, cur, val) != cur);
+	}
+	rcu_read_unlock();
+}
+
+/**
+ * tipc_aead_tfm_next - Move TFM entry to the next one in list and return it
+ */
+static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead)
+{
+	struct tipc_tfm **tfm_entry = this_cpu_ptr(aead->tfm_entry);
+
+	*tfm_entry = list_next_entry(*tfm_entry, list);
+	return (*tfm_entry)->tfm;
+}
+
+/**
+ * tipc_aead_init - Initiate TIPC AEAD
+ * @aead: returned new TIPC AEAD key handle pointer
+ * @ukey: pointer to user key data
+ * @mode: the key mode
+ *
+ * Allocate a (list of) new cipher transformation (TFM) with the specific user
+ * key data if valid. The number of the allocated TFMs can be set via the sysfs
+ * "net/tipc/max_tfms" first.
+ * Also, all the other AEAD data are also initialized.
+ *
+ * Return: 0 if the initiation is successful, otherwise: < 0
+ */
+static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
+			  u8 mode)
+{
+	struct tipc_tfm *tfm_entry, *head;
+	struct crypto_aead *tfm;
+	struct tipc_aead *tmp;
+	int keylen, err, cpu;
+	int tfm_cnt = 0;
+
+	if (unlikely(*aead))
+		return -EEXIST;
+
+	/* Allocate a new AEAD */
+	tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
+	if (unlikely(!tmp))
+		return -ENOMEM;
+
+	/* The key consists of two parts: [AES-KEY][SALT] */
+	keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
+
+	/* Allocate per-cpu TFM entry pointer */
+	tmp->tfm_entry = alloc_percpu(struct tipc_tfm *);
+	if (!tmp->tfm_entry) {
+		kzfree(tmp);
+		return -ENOMEM;
+	}
+
+	/* Make a list of TFMs with the user key data */
+	do {
+		tfm = crypto_alloc_aead(ukey->alg_name, 0, 0);
+		if (IS_ERR(tfm)) {
+			err = PTR_ERR(tfm);
+			break;
+		}
+
+		if (unlikely(!tfm_cnt &&
+			     crypto_aead_ivsize(tfm) != TIPC_AES_GCM_IV_SIZE)) {
+			crypto_free_aead(tfm);
+			err = -ENOTSUPP;
+			break;
+		}
+
+		err |= crypto_aead_setauthsize(tfm, TIPC_AES_GCM_TAG_SIZE);
+		err |= crypto_aead_setkey(tfm, ukey->key, keylen);
+		if (unlikely(err)) {
+			crypto_free_aead(tfm);
+			break;
+		}
+
+		tfm_entry = kmalloc(sizeof(*tfm_entry), GFP_KERNEL);
+		if (unlikely(!tfm_entry)) {
+			crypto_free_aead(tfm);
+			err = -ENOMEM;
+			break;
+		}
+		INIT_LIST_HEAD(&tfm_entry->list);
+		tfm_entry->tfm = tfm;
+
+		/* First entry? */
+		if (!tfm_cnt) {
+			head = tfm_entry;
+			for_each_possible_cpu(cpu) {
+				*per_cpu_ptr(tmp->tfm_entry, cpu) = head;
+			}
+		} else {
+			list_add_tail(&tfm_entry->list, &head->list);
+		}
+
+	} while (++tfm_cnt < sysctl_tipc_max_tfms);
+
+	/* Not any TFM is allocated? */
+	if (!tfm_cnt) {
+		free_percpu(tmp->tfm_entry);
+		kzfree(tmp);
+		return err;
+	}
+
+	/* Copy some chars from the user key as a hint */
+	memcpy(tmp->hint, ukey->key, TIPC_AEAD_HINT_LEN);
+	tmp->hint[TIPC_AEAD_HINT_LEN] = '\0';
+
+	/* Initialize the other data */
+	tmp->mode = mode;
+	tmp->cloned = NULL;
+	tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
+	memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
+	atomic_set(&tmp->users, 0);
+	atomic64_set(&tmp->seqno, 0);
+	refcount_set(&tmp->refcnt, 1);
+
+	*aead = tmp;
+	return 0;
+}
+
+/**
+ * tipc_aead_clone - Clone a TIPC AEAD key
+ * @dst: dest key for the cloning
+ * @src: source key to clone from
+ *
+ * Make a "copy" of the source AEAD key data to the dest, the TFMs list is
+ * common for the keys.
+ * A reference to the source is hold in the "cloned" pointer for the later
+ * freeing purposes.
+ *
+ * Note: this must be done in cluster-key mode only!
+ * Return: 0 in case of success, otherwise < 0
+ */
+static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src)
+{
+	struct tipc_aead *aead;
+	int cpu;
+
+	if (!src)
+		return -ENOKEY;
+
+	if (src->mode != CLUSTER_KEY)
+		return -EINVAL;
+
+	if (unlikely(*dst))
+		return -EEXIST;
+
+	aead = kzalloc(sizeof(*aead), GFP_ATOMIC);
+	if (unlikely(!aead))
+		return -ENOMEM;
+
+	aead->tfm_entry = alloc_percpu_gfp(struct tipc_tfm *, GFP_ATOMIC);
+	if (unlikely(!aead->tfm_entry)) {
+		kzfree(aead);
+		return -ENOMEM;
+	}
+
+	for_each_possible_cpu(cpu) {
+		*per_cpu_ptr(aead->tfm_entry, cpu) =
+				*per_cpu_ptr(src->tfm_entry, cpu);
+	}
+
+	memcpy(aead->hint, src->hint, sizeof(src->hint));
+	aead->mode = src->mode;
+	aead->salt = src->salt;
+	aead->authsize = src->authsize;
+	atomic_set(&aead->users, 0);
+	atomic64_set(&aead->seqno, 0);
+	refcount_set(&aead->refcnt, 1);
+
+	WARN_ON(!refcount_inc_not_zero(&src->refcnt));
+	aead->cloned = src;
+
+	*dst = aead;
+	return 0;
+}
+
+/**
+ * tipc_aead_mem_alloc - Allocate memory for AEAD request operations
+ * @tfm: cipher handle to be registered with the request
+ * @crypto_ctx_size: size of crypto context for callback
+ * @iv: returned pointer to IV data
+ * @req: returned pointer to AEAD request data
+ * @sg: returned pointer to SG lists
+ * @nsg: number of SG lists to be allocated
+ *
+ * Allocate memory to store the crypto context data, AEAD request, IV and SG
+ * lists, the memory layout is as follows:
+ * crypto_ctx || iv || aead_req || sg[]
+ *
+ * Return: the pointer to the memory areas in case of success, otherwise NULL
+ */
+static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
+				 unsigned int crypto_ctx_size,
+				 u8 **iv, struct aead_request **req,
+				 struct scatterlist **sg, int nsg)
+{
+	unsigned int iv_size, req_size;
+	unsigned int len;
+	u8 *mem;
+
+	iv_size = crypto_aead_ivsize(tfm);
+	req_size = sizeof(**req) + crypto_aead_reqsize(tfm);
+
+	len = crypto_ctx_size;
+	len += iv_size;
+	len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1);
+	len = ALIGN(len, crypto_tfm_ctx_alignment());
+	len += req_size;
+	len = ALIGN(len, __alignof__(struct scatterlist));
+	len += nsg * sizeof(**sg);
+
+	mem = kmalloc(len, GFP_ATOMIC);
+	if (!mem)
+		return NULL;
+
+	*iv = (u8 *)PTR_ALIGN(mem + crypto_ctx_size,
+			      crypto_aead_alignmask(tfm) + 1);
+	*req = (struct aead_request *)PTR_ALIGN(*iv + iv_size,
+						crypto_tfm_ctx_alignment());
+	*sg = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
+					      __alignof__(struct scatterlist));
+
+	return (void *)mem;
+}
+
+/**
+ * tipc_aead_encrypt - Encrypt a message
+ * @aead: TIPC AEAD key for the message encryption
+ * @skb: the input/output skb
+ * @b: TIPC bearer where the message will be delivered after the encryption
+ * @dst: the destination media address
+ * @__dnode: TIPC dest node if "known"
+ *
+ * Return:
+ * 0                   : if the encryption has completed
+ * -EINPROGRESS/-EBUSY : if a callback will be performed
+ * < 0                 : the encryption has failed
+ */
+static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
+			     struct tipc_bearer *b,
+			     struct tipc_media_addr *dst,
+			     struct tipc_node *__dnode)
+{
+	struct crypto_aead *tfm = tipc_aead_tfm_next(aead);
+	struct tipc_crypto_tx_ctx *tx_ctx;
+	struct aead_request *req;
+	struct sk_buff *trailer;
+	struct scatterlist *sg;
+	struct tipc_ehdr *ehdr;
+	int ehsz, len, tailen, nsg, rc;
+	void *ctx;
+	u32 salt;
+	u8 *iv;
+
+	/* Make sure message len at least 4-byte aligned */
+	len = ALIGN(skb->len, 4);
+	tailen = len - skb->len + aead->authsize;
+
+	/* Expand skb tail for authentication tag:
+	 * As for simplicity, we'd have made sure skb having enough tailroom
+	 * for authentication tag @skb allocation. Even when skb is nonlinear
+	 * but there is no frag_list, it should be still fine!
+	 * Otherwise, we must cow it to be a writable buffer with the tailroom.
+	 */
+#ifdef TIPC_CRYPTO_DEBUG
+	SKB_LINEAR_ASSERT(skb);
+	if (tailen > skb_tailroom(skb)) {
+		pr_warn("TX: skb tailroom is not enough: %d, requires: %d\n",
+			skb_tailroom(skb), tailen);
+	}
+#endif
+
+	if (unlikely(!skb_cloned(skb) && tailen <= skb_tailroom(skb))) {
+		nsg = 1;
+		trailer = skb;
+	} else {
+		/* TODO: We could avoid skb_cow_data() if skb has no frag_list
+		 * e.g. by skb_fill_page_desc() to add another page to the skb
+		 * with the wanted tailen... However, page skbs look not often,
+		 * so take it easy now!
+		 * Cloned skbs e.g. from link_xmit() seems no choice though :(
+		 */
+		nsg = skb_cow_data(skb, tailen, &trailer);
+		if (unlikely(nsg < 0)) {
+			pr_err("TX: skb_cow_data() returned %d\n", nsg);
+			return nsg;
+		}
+	}
+
+	pskb_put(skb, trailer, tailen);
+
+	/* Allocate memory for the AEAD operation */
+	ctx = tipc_aead_mem_alloc(tfm, sizeof(*tx_ctx), &iv, &req, &sg, nsg);
+	if (unlikely(!ctx))
+		return -ENOMEM;
+	TIPC_SKB_CB(skb)->crypto_ctx = ctx;
+
+	/* Map skb to the sg lists */
+	sg_init_table(sg, nsg);
+	rc = skb_to_sgvec(skb, sg, 0, skb->len);
+	if (unlikely(rc < 0)) {
+		pr_err("TX: skb_to_sgvec() returned %d, nsg %d!\n", rc, nsg);
+		goto exit;
+	}
+
+	/* Prepare IV: [SALT (4 octets)][SEQNO (8 octets)]
+	 * In case we're in cluster-key mode, SALT is varied by xor-ing with
+	 * the source address (or w0 of id), otherwise with the dest address
+	 * if dest is known.
+	 */
+	ehdr = (struct tipc_ehdr *)skb->data;
+	salt = aead->salt;
+	if (aead->mode == CLUSTER_KEY)
+		salt ^= ehdr->addr; /* __be32 */
+	else if (__dnode)
+		salt ^= tipc_node_get_addr(__dnode);
+	memcpy(iv, &salt, 4);
+	memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
+
+	/* Prepare request */
+	ehsz = tipc_ehdr_size(ehdr);
+	aead_request_set_tfm(req, tfm);
+	aead_request_set_ad(req, ehsz);
+	aead_request_set_crypt(req, sg, sg, len - ehsz, iv);
+
+	/* Set callback function & data */
+	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				  tipc_aead_encrypt_done, skb);
+	tx_ctx = (struct tipc_crypto_tx_ctx *)ctx;
+	tx_ctx->aead = aead;
+	tx_ctx->bearer = b;
+	memcpy(&tx_ctx->dst, dst, sizeof(*dst));
+
+	/* Hold bearer */
+	if (unlikely(!tipc_bearer_hold(b))) {
+		rc = -ENODEV;
+		goto exit;
+	}
+
+	/* Now, do encrypt */
+	rc = crypto_aead_encrypt(req);
+	if (rc == -EINPROGRESS || rc == -EBUSY)
+		return rc;
+
+	tipc_bearer_put(b);
+
+exit:
+	kfree(ctx);
+	TIPC_SKB_CB(skb)->crypto_ctx = NULL;
+	return rc;
+}
+
+static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err)
+{
+	struct sk_buff *skb = base->data;
+	struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
+	struct tipc_bearer *b = tx_ctx->bearer;
+	struct tipc_aead *aead = tx_ctx->aead;
+	struct tipc_crypto *tx = aead->crypto;
+	struct net *net = tx->net;
+
+	switch (err) {
+	case 0:
+		this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]);
+		if (likely(test_bit(0, &b->up)))
+			b->media->send_msg(net, skb, b, &tx_ctx->dst);
+		else
+			kfree_skb(skb);
+		break;
+	case -EINPROGRESS:
+		return;
+	default:
+		this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]);
+		kfree_skb(skb);
+		break;
+	}
+
+	kfree(tx_ctx);
+	tipc_bearer_put(b);
+	tipc_aead_put(aead);
+}
+
+/**
+ * tipc_aead_decrypt - Decrypt an encrypted message
+ * @net: struct net
+ * @aead: TIPC AEAD for the message decryption
+ * @skb: the input/output skb
+ * @b: TIPC bearer where the message has been received
+ *
+ * Return:
+ * 0                   : if the decryption has completed
+ * -EINPROGRESS/-EBUSY : if a callback will be performed
+ * < 0                 : the decryption has failed
+ */
+static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
+			     struct sk_buff *skb, struct tipc_bearer *b)
+{
+	struct tipc_crypto_rx_ctx *rx_ctx;
+	struct aead_request *req;
+	struct crypto_aead *tfm;
+	struct sk_buff *unused;
+	struct scatterlist *sg;
+	struct tipc_ehdr *ehdr;
+	int ehsz, nsg, rc;
+	void *ctx;
+	u32 salt;
+	u8 *iv;
+
+	if (unlikely(!aead))
+		return -ENOKEY;
+
+	/* Cow skb data if needed */
+	if (likely(!skb_cloned(skb) &&
+		   (!skb_is_nonlinear(skb) || !skb_has_frag_list(skb)))) {
+		nsg = 1 + skb_shinfo(skb)->nr_frags;
+	} else {
+		nsg = skb_cow_data(skb, 0, &unused);
+		if (unlikely(nsg < 0)) {
+			pr_err("RX: skb_cow_data() returned %d\n", nsg);
+			return nsg;
+		}
+	}
+
+	/* Allocate memory for the AEAD operation */
+	tfm = tipc_aead_tfm_next(aead);
+	ctx = tipc_aead_mem_alloc(tfm, sizeof(*rx_ctx), &iv, &req, &sg, nsg);
+	if (unlikely(!ctx))
+		return -ENOMEM;
+	TIPC_SKB_CB(skb)->crypto_ctx = ctx;
+
+	/* Map skb to the sg lists */
+	sg_init_table(sg, nsg);
+	rc = skb_to_sgvec(skb, sg, 0, skb->len);
+	if (unlikely(rc < 0)) {
+		pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg);
+		goto exit;
+	}
+
+	/* Reconstruct IV: */
+	ehdr = (struct tipc_ehdr *)skb->data;
+	salt = aead->salt;
+	if (aead->mode == CLUSTER_KEY)
+		salt ^= ehdr->addr; /* __be32 */
+	else if (ehdr->destined)
+		salt ^= tipc_own_addr(net);
+	memcpy(iv, &salt, 4);
+	memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
+
+	/* Prepare request */
+	ehsz = tipc_ehdr_size(ehdr);
+	aead_request_set_tfm(req, tfm);
+	aead_request_set_ad(req, ehsz);
+	aead_request_set_crypt(req, sg, sg, skb->len - ehsz, iv);
+
+	/* Set callback function & data */
+	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				  tipc_aead_decrypt_done, skb);
+	rx_ctx = (struct tipc_crypto_rx_ctx *)ctx;
+	rx_ctx->aead = aead;
+	rx_ctx->bearer = b;
+
+	/* Hold bearer */
+	if (unlikely(!tipc_bearer_hold(b))) {
+		rc = -ENODEV;
+		goto exit;
+	}
+
+	/* Now, do decrypt */
+	rc = crypto_aead_decrypt(req);
+	if (rc == -EINPROGRESS || rc == -EBUSY)
+		return rc;
+
+	tipc_bearer_put(b);
+
+exit:
+	kfree(ctx);
+	TIPC_SKB_CB(skb)->crypto_ctx = NULL;
+	return rc;
+}
+
+static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err)
+{
+	struct sk_buff *skb = base->data;
+	struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
+	struct tipc_bearer *b = rx_ctx->bearer;
+	struct tipc_aead *aead = rx_ctx->aead;
+	struct tipc_crypto_stats __percpu *stats = aead->crypto->stats;
+	struct net *net = aead->crypto->net;
+
+	switch (err) {
+	case 0:
+		this_cpu_inc(stats->stat[STAT_ASYNC_OK]);
+		break;
+	case -EINPROGRESS:
+		return;
+	default:
+		this_cpu_inc(stats->stat[STAT_ASYNC_NOK]);
+		break;
+	}
+
+	kfree(rx_ctx);
+	tipc_crypto_rcv_complete(net, aead, b, &skb, err);
+	if (likely(skb)) {
+		if (likely(test_bit(0, &b->up)))
+			tipc_rcv(net, skb, b);
+		else
+			kfree_skb(skb);
+	}
+
+	tipc_bearer_put(b);
+}
+
+static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr)
+{
+	return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
+}
+
+/**
+ * tipc_ehdr_validate - Validate an encryption message
+ * @skb: the message buffer
+ *
+ * Returns "true" if this is a valid encryption message, otherwise "false"
+ */
+bool tipc_ehdr_validate(struct sk_buff *skb)
+{
+	struct tipc_ehdr *ehdr;
+	int ehsz;
+
+	if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE)))
+		return false;
+
+	ehdr = (struct tipc_ehdr *)skb->data;
+	if (unlikely(ehdr->version != TIPC_EVERSION))
+		return false;
+	ehsz = tipc_ehdr_size(ehdr);
+	if (unlikely(!pskb_may_pull(skb, ehsz)))
+		return false;
+	if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE))
+		return false;
+	if (unlikely(!ehdr->tx_key))
+		return false;
+
+	return true;
+}
+
+/**
+ * tipc_ehdr_build - Build TIPC encryption message header
+ * @net: struct net
+ * @aead: TX AEAD key to be used for the message encryption
+ * @tx_key: key id used for the message encryption
+ * @skb: input/output message skb
+ * @__rx: RX crypto handle if dest is "known"
+ *
+ * Return: the header size if the building is successful, otherwise < 0
+ */
+static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
+			   u8 tx_key, struct sk_buff *skb,
+			   struct tipc_crypto *__rx)
+{
+	struct tipc_msg *hdr = buf_msg(skb);
+	struct tipc_ehdr *ehdr;
+	u32 user = msg_user(hdr);
+	u64 seqno;
+	int ehsz;
+
+	/* Make room for encryption header */
+	ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
+	WARN_ON(skb_headroom(skb) < ehsz);
+	ehdr = (struct tipc_ehdr *)skb_push(skb, ehsz);
+
+	/* Obtain a seqno first:
+	 * Use the key seqno (= cluster wise) if dest is unknown or we're in
+	 * cluster key mode, otherwise it's better for a per-peer seqno!
+	 */
+	if (!__rx || aead->mode == CLUSTER_KEY)
+		seqno = atomic64_inc_return(&aead->seqno);
+	else
+		seqno = atomic64_inc_return(&__rx->sndnxt);
+
+	/* Revoke the key if seqno is wrapped around */
+	if (unlikely(!seqno))
+		return tipc_crypto_key_revoke(net, tx_key);
+
+	/* Word 1-2 */
+	ehdr->seqno = cpu_to_be64(seqno);
+
+	/* Words 0, 3- */
+	ehdr->version = TIPC_EVERSION;
+	ehdr->user = 0;
+	ehdr->keepalive = 0;
+	ehdr->tx_key = tx_key;
+	ehdr->destined = (__rx) ? 1 : 0;
+	ehdr->rx_key_active = (__rx) ? __rx->key.active : 0;
+	ehdr->reserved_1 = 0;
+	ehdr->reserved_2 = 0;
+
+	switch (user) {
+	case LINK_CONFIG:
+		ehdr->user = LINK_CONFIG;
+		memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN);
+		break;
+	default:
+		if (user == LINK_PROTOCOL && msg_type(hdr) == STATE_MSG) {
+			ehdr->user = LINK_PROTOCOL;
+			ehdr->keepalive = msg_is_keepalive(hdr);
+		}
+		ehdr->addr = hdr->hdr[3];
+		break;
+	}
+
+	return ehsz;
+}
+
+static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
+					     u8 new_passive,
+					     u8 new_active,
+					     u8 new_pending)
+{
+#ifdef TIPC_CRYPTO_DEBUG
+	struct tipc_key old = c->key;
+	char buf[32];
+#endif
+
+	c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) |
+		      ((new_active  & KEY_MASK) << (KEY_BITS)) |
+		      ((new_pending & KEY_MASK));
+
+#ifdef TIPC_CRYPTO_DEBUG
+	pr_info("%s(%s): key changing %s ::%pS\n",
+		(c->node) ? "RX" : "TX",
+		(c->node) ? tipc_node_get_id_str(c->node) :
+			    tipc_own_id_string(c->net),
+		tipc_key_change_dump(old, c->key, buf),
+		__builtin_return_address(0));
+#endif
+}
+
+/**
+ * tipc_crypto_key_init - Initiate a new user / AEAD key
+ * @c: TIPC crypto to which new key is attached
+ * @ukey: the user key
+ * @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY)
+ *
+ * A new TIPC AEAD key will be allocated and initiated with the specified user
+ * key, then attached to the TIPC crypto.
+ *
+ * Return: new key id in case of success, otherwise: < 0
+ */
+int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
+			 u8 mode)
+{
+	struct tipc_aead *aead = NULL;
+	int rc = 0;
+
+	/* Initiate with the new user key */
+	rc = tipc_aead_init(&aead, ukey, mode);
+
+	/* Attach it to the crypto */
+	if (likely(!rc)) {
+		rc = tipc_crypto_key_attach(c, aead, 0);
+		if (rc < 0)
+			tipc_aead_free(&aead->rcu);
+	}
+
+	pr_info("%s(%s): key initiating, rc %d!\n",
+		(c->node) ? "RX" : "TX",
+		(c->node) ? tipc_node_get_id_str(c->node) :
+			    tipc_own_id_string(c->net),
+		rc);
+
+	return rc;
+}
+
+/**
+ * tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto
+ * @c: TIPC crypto to which the new AEAD key is attached
+ * @aead: the new AEAD key pointer
+ * @pos: desired slot in the crypto key array, = 0 if any!
+ *
+ * Return: new key id in case of success, otherwise: -EBUSY
+ */
+static int tipc_crypto_key_attach(struct tipc_crypto *c,
+				  struct tipc_aead *aead, u8 pos)
+{
+	u8 new_pending, new_passive, new_key;
+	struct tipc_key key;
+	int rc = -EBUSY;
+
+	spin_lock_bh(&c->lock);
+	key = c->key;
+	if (key.active && key.passive)
+		goto exit;
+	if (key.passive && !tipc_aead_users(c->aead[key.passive]))
+		goto exit;
+	if (key.pending) {
+		if (pos)
+			goto exit;
+		if (tipc_aead_users(c->aead[key.pending]) > 0)
+			goto exit;
+		/* Replace it */
+		new_pending = key.pending;
+		new_passive = key.passive;
+		new_key = new_pending;
+	} else {
+		if (pos) {
+			if (key.active && pos != key_next(key.active)) {
+				new_pending = key.pending;
+				new_passive = pos;
+				new_key = new_passive;
+				goto attach;
+			} else if (!key.active && !key.passive) {
+				new_pending = pos;
+				new_passive = key.passive;
+				new_key = new_pending;
+				goto attach;
+			}
+		}
+		new_pending = key_next(key.active ?: key.passive);
+		new_passive = key.passive;
+		new_key = new_pending;
+	}
+
+attach:
+	aead->crypto = c;
+	tipc_crypto_key_set_state(c, new_passive, key.active, new_pending);
+	tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock);
+
+	c->working = 1;
+	c->timer1 = jiffies;
+	c->timer2 = jiffies;
+	rc = new_key;
+
+exit:
+	spin_unlock_bh(&c->lock);
+	return rc;
+}
+
+void tipc_crypto_key_flush(struct tipc_crypto *c)
+{
+	int k;
+
+	spin_lock_bh(&c->lock);
+	c->working = 0;
+	tipc_crypto_key_set_state(c, 0, 0, 0);
+	for (k = KEY_MIN; k <= KEY_MAX; k++)
+		tipc_crypto_key_detach(c->aead[k], &c->lock);
+	atomic_set(&c->peer_rx_active, 0);
+	atomic64_set(&c->sndnxt, 0);
+	spin_unlock_bh(&c->lock);
+}
+
+/**
+ * tipc_crypto_key_try_align - Align RX keys if possible
+ * @rx: RX crypto handle
+ * @new_pending: new pending slot if aligned (= TX key from peer)
+ *
+ * Peer has used an unknown key slot, this only happens when peer has left and
+ * rejoned, or we are newcomer.
+ * That means, there must be no active key but a pending key at unaligned slot.
+ * If so, we try to move the pending key to the new slot.
+ * Note: A potential passive key can exist, it will be shifted correspondingly!
+ *
+ * Return: "true" if key is successfully aligned, otherwise "false"
+ */
+static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
+{
+	struct tipc_aead *tmp1, *tmp2 = NULL;
+	struct tipc_key key;
+	bool aligned = false;
+	u8 new_passive = 0;
+	int x;
+
+	spin_lock(&rx->lock);
+	key = rx->key;
+	if (key.pending == new_pending) {
+		aligned = true;
+		goto exit;
+	}
+	if (key.active)
+		goto exit;
+	if (!key.pending)
+		goto exit;
+	if (tipc_aead_users(rx->aead[key.pending]) > 0)
+		goto exit;
+
+	/* Try to "isolate" this pending key first */
+	tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock);
+	if (!refcount_dec_if_one(&tmp1->refcnt))
+		goto exit;
+	rcu_assign_pointer(rx->aead[key.pending], NULL);
+
+	/* Move passive key if any */
+	if (key.passive) {
+		tipc_aead_rcu_swap(rx->aead[key.passive], tmp2, &rx->lock);
+		x = (key.passive - key.pending + new_pending) % KEY_MAX;
+		new_passive = (x <= 0) ? x + KEY_MAX : x;
+	}
+
+	/* Re-allocate the key(s) */
+	tipc_crypto_key_set_state(rx, new_passive, 0, new_pending);
+	rcu_assign_pointer(rx->aead[new_pending], tmp1);
+	if (new_passive)
+		rcu_assign_pointer(rx->aead[new_passive], tmp2);
+	refcount_set(&tmp1->refcnt, 1);
+	aligned = true;
+	pr_info("RX(%s): key is aligned!\n", tipc_node_get_id_str(rx->node));
+
+exit:
+	spin_unlock(&rx->lock);
+	return aligned;
+}
+
+/**
+ * tipc_crypto_key_pick_tx - Pick one TX key for message decryption
+ * @tx: TX crypto handle
+ * @rx: RX crypto handle (can be NULL)
+ * @skb: the message skb which will be decrypted later
+ *
+ * This function looks up the existing TX keys and pick one which is suitable
+ * for the message decryption, that must be a cluster key and not used before
+ * on the same message (i.e. recursive).
+ *
+ * Return: the TX AEAD key handle in case of success, otherwise NULL
+ */
+static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
+						 struct tipc_crypto *rx,
+						 struct sk_buff *skb)
+{
+	struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb);
+	struct tipc_aead *aead = NULL;
+	struct tipc_key key = tx->key;
+	u8 k, i = 0;
+
+	/* Initialize data if not yet */
+	if (!skb_cb->tx_clone_deferred) {
+		skb_cb->tx_clone_deferred = 1;
+		memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
+	}
+
+	skb_cb->tx_clone_ctx.rx = rx;
+	if (++skb_cb->tx_clone_ctx.recurs > 2)
+		return NULL;
+
+	/* Pick one TX key */
+	spin_lock(&tx->lock);
+	do {
+		k = (i == 0) ? key.pending :
+			((i == 1) ? key.active : key.passive);
+		if (!k)
+			continue;
+		aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock);
+		if (!aead)
+			continue;
+		if (aead->mode != CLUSTER_KEY ||
+		    aead == skb_cb->tx_clone_ctx.last) {
+			aead = NULL;
+			continue;
+		}
+		/* Ok, found one cluster key */
+		skb_cb->tx_clone_ctx.last = aead;
+		WARN_ON(skb->next);
+		skb->next = skb_clone(skb, GFP_ATOMIC);
+		if (unlikely(!skb->next))
+			pr_warn("Failed to clone skb for next round if any\n");
+		WARN_ON(!refcount_inc_not_zero(&aead->refcnt));
+		break;
+	} while (++i < 3);
+	spin_unlock(&tx->lock);
+
+	return aead;
+}
+
+/**
+ * tipc_crypto_key_synch: Synch own key data according to peer key status
+ * @rx: RX crypto handle
+ * @new_rx_active: latest RX active key from peer
+ * @hdr: TIPCv2 message
+ *
+ * This function updates the peer node related data as the peer RX active key
+ * has changed, so the number of TX keys' users on this node are increased and
+ * decreased correspondingly.
+ *
+ * The "per-peer" sndnxt is also reset when the peer key has switched.
+ */
+static void tipc_crypto_key_synch(struct tipc_crypto *rx, u8 new_rx_active,
+				  struct tipc_msg *hdr)
+{
+	struct net *net = rx->net;
+	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
+	u8 cur_rx_active;
+
+	/* TX might be even not ready yet */
+	if (unlikely(!tx->key.active && !tx->key.pending))
+		return;
+
+	cur_rx_active = atomic_read(&rx->peer_rx_active);
+	if (likely(cur_rx_active == new_rx_active))
+		return;
+
+	/* Make sure this message destined for this node */
+	if (unlikely(msg_short(hdr) ||
+		     msg_destnode(hdr) != tipc_own_addr(net)))
+		return;
+
+	/* Peer RX active key has changed, try to update owns' & TX users */
+	if (atomic_cmpxchg(&rx->peer_rx_active,
+			   cur_rx_active,
+			   new_rx_active) == cur_rx_active) {
+		if (new_rx_active)
+			tipc_aead_users_inc(tx->aead[new_rx_active], INT_MAX);
+		if (cur_rx_active)
+			tipc_aead_users_dec(tx->aead[cur_rx_active], 0);
+
+		atomic64_set(&rx->sndnxt, 0);
+		/* Mark the point TX key users changed */
+		tx->timer1 = jiffies;
+
+#ifdef TIPC_CRYPTO_DEBUG
+		pr_info("TX(%s): key users changed %d-- %d++, peer RX(%s)\n",
+			tipc_own_id_string(net), cur_rx_active,
+			new_rx_active, tipc_node_get_id_str(rx->node));
+#endif
+	}
+}
+
+static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
+{
+	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
+	struct tipc_key key;
+
+	spin_lock(&tx->lock);
+	key = tx->key;
+	WARN_ON(!key.active || tx_key != key.active);
+
+	/* Free the active key */
+	tipc_crypto_key_set_state(tx, key.passive, 0, key.pending);
+	tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
+	spin_unlock(&tx->lock);
+
+	pr_warn("TX(%s): key is revoked!\n", tipc_own_id_string(net));
+	return -EKEYREVOKED;
+}
+
+int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
+		      struct tipc_node *node)
+{
+	struct tipc_crypto *c;
+
+	if (*crypto)
+		return -EEXIST;
+
+	/* Allocate crypto */
+	c = kzalloc(sizeof(*c), GFP_ATOMIC);
+	if (!c)
+		return -ENOMEM;
+
+	/* Allocate statistic structure */
+	c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
+	if (!c->stats) {
+		kzfree(c);
+		return -ENOMEM;
+	}
+
+	c->working = 0;
+	c->net = net;
+	c->node = node;
+	tipc_crypto_key_set_state(c, 0, 0, 0);
+	atomic_set(&c->peer_rx_active, 0);
+	atomic64_set(&c->sndnxt, 0);
+	c->timer1 = jiffies;
+	c->timer2 = jiffies;
+	spin_lock_init(&c->lock);
+	*crypto = c;
+
+	return 0;
+}
+
+void tipc_crypto_stop(struct tipc_crypto **crypto)
+{
+	struct tipc_crypto *c, *tx, *rx;
+	bool is_rx;
+	u8 k;
+
+	if (!*crypto)
+		return;
+
+	rcu_read_lock();
+	/* RX stopping? => decrease TX key users if any */
+	is_rx = !!((*crypto)->node);
+	if (is_rx) {
+		rx = *crypto;
+		tx = tipc_net(rx->net)->crypto_tx;
+		k = atomic_read(&rx->peer_rx_active);
+		if (k) {
+			tipc_aead_users_dec(tx->aead[k], 0);
+			/* Mark the point TX key users changed */
+			tx->timer1 = jiffies;
+		}
+	}
+
+	/* Release AEAD keys */
+	c = *crypto;
+	for (k = KEY_MIN; k <= KEY_MAX; k++)
+		tipc_aead_put(rcu_dereference(c->aead[k]));
+	rcu_read_unlock();
+
+	pr_warn("%s(%s) has been purged, node left!\n",
+		(is_rx) ? "RX" : "TX",
+		(is_rx) ? tipc_node_get_id_str((*crypto)->node) :
+			  tipc_own_id_string((*crypto)->net));
+
+	/* Free this crypto statistics */
+	free_percpu(c->stats);
+
+	*crypto = NULL;
+	kzfree(c);
+}
+
+void tipc_crypto_timeout(struct tipc_crypto *rx)
+{
+	struct tipc_net *tn = tipc_net(rx->net);
+	struct tipc_crypto *tx = tn->crypto_tx;
+	struct tipc_key key;
+	u8 new_pending, new_passive;
+	int cmd;
+
+	/* TX key activating:
+	 * The pending key (users > 0) -> active
+	 * The active key if any (users == 0) -> free
+	 */
+	spin_lock(&tx->lock);
+	key = tx->key;
+	if (key.active && tipc_aead_users(tx->aead[key.active]) > 0)
+		goto s1;
+	if (!key.pending || tipc_aead_users(tx->aead[key.pending]) <= 0)
+		goto s1;
+	if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_LIM))
+		goto s1;
+
+	tipc_crypto_key_set_state(tx, key.passive, key.pending, 0);
+	if (key.active)
+		tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
+	this_cpu_inc(tx->stats->stat[STAT_SWITCHES]);
+	pr_info("TX(%s): key %d is activated!\n", tipc_own_id_string(tx->net),
+		key.pending);
+
+s1:
+	spin_unlock(&tx->lock);
+
+	/* RX key activating:
+	 * The pending key (users > 0) -> active
+	 * The active key if any -> passive, freed later
+	 */
+	spin_lock(&rx->lock);
+	key = rx->key;
+	if (!key.pending || tipc_aead_users(rx->aead[key.pending]) <= 0)
+		goto s2;
+
+	new_pending = (key.passive &&
+		       !tipc_aead_users(rx->aead[key.passive])) ?
+				       key.passive : 0;
+	new_passive = (key.active) ?: ((new_pending) ? 0 : key.passive);
+	tipc_crypto_key_set_state(rx, new_passive, key.pending, new_pending);
+	this_cpu_inc(rx->stats->stat[STAT_SWITCHES]);
+	pr_info("RX(%s): key %d is activated!\n",
+		tipc_node_get_id_str(rx->node),	key.pending);
+	goto s5;
+
+s2:
+	/* RX key "faulty" switching:
+	 * The faulty pending key (users < -30) -> passive
+	 * The passive key (users = 0) -> pending
+	 * Note: This only happens after RX deactivated - s3!
+	 */
+	key = rx->key;
+	if (!key.pending || tipc_aead_users(rx->aead[key.pending]) > -30)
+		goto s3;
+	if (!key.passive || tipc_aead_users(rx->aead[key.passive]) != 0)
+		goto s3;
+
+	new_pending = key.passive;
+	new_passive = key.pending;
+	tipc_crypto_key_set_state(rx, new_passive, key.active, new_pending);
+	goto s5;
+
+s3:
+	/* RX key deactivating:
+	 * The passive key if any -> pending
+	 * The active key -> passive (users = 0) / pending
+	 * The pending key if any -> passive (users = 0)
+	 */
+	key = rx->key;
+	if (!key.active)
+		goto s4;
+	if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM))
+		goto s4;
+
+	new_pending = (key.passive) ?: key.active;
+	new_passive = (key.passive) ? key.active : key.pending;
+	tipc_aead_users_set(rx->aead[new_pending], 0);
+	if (new_passive)
+		tipc_aead_users_set(rx->aead[new_passive], 0);
+	tipc_crypto_key_set_state(rx, new_passive, 0, new_pending);
+	pr_info("RX(%s): key %d is deactivated!\n",
+		tipc_node_get_id_str(rx->node), key.active);
+	goto s5;
+
+s4:
+	/* RX key passive -> freed: */
+	key = rx->key;
+	if (!key.passive || !tipc_aead_users(rx->aead[key.passive]))
+		goto s5;
+	if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM))
+		goto s5;
+
+	tipc_crypto_key_set_state(rx, 0, key.active, key.pending);
+	tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock);
+	pr_info("RX(%s): key %d is freed!\n", tipc_node_get_id_str(rx->node),
+		key.passive);
+
+s5:
+	spin_unlock(&rx->lock);
+
+	/* Limit max_tfms & do debug commands if needed */
+	if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM))
+		return;
+
+	cmd = sysctl_tipc_max_tfms;
+	sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF;
+	tipc_crypto_do_cmd(rx->net, cmd);
+}
+
+/**
+ * tipc_crypto_xmit - Build & encrypt TIPC message for xmit
+ * @net: struct net
+ * @skb: input/output message skb pointer
+ * @b: bearer used for xmit later
+ * @dst: destination media address
+ * @__dnode: destination node for reference if any
+ *
+ * First, build an encryption message header on the top of the message, then
+ * encrypt the original TIPC message by using the active or pending TX key.
+ * If the encryption is successful, the encrypted skb is returned directly or
+ * via the callback.
+ * Otherwise, the skb is freed!
+ *
+ * Return:
+ * 0                   : the encryption has succeeded (or no encryption)
+ * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made
+ * -ENOKEK             : the encryption has failed due to no key
+ * -EKEYREVOKED        : the encryption has failed due to key revoked
+ * -ENOMEM             : the encryption has failed due to no memory
+ * < 0                 : the encryption has failed due to other reasons
+ */
+int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
+		     struct tipc_bearer *b, struct tipc_media_addr *dst,
+		     struct tipc_node *__dnode)
+{
+	struct tipc_crypto *__rx = tipc_node_crypto_rx(__dnode);
+	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
+	struct tipc_crypto_stats __percpu *stats = tx->stats;
+	struct tipc_key key = tx->key;
+	struct tipc_aead *aead = NULL;
+	struct sk_buff *probe;
+	int rc = -ENOKEY;
+	u8 tx_key;
+
+	/* No encryption? */
+	if (!tx->working)
+		return 0;
+
+	/* Try with the pending key if available and:
+	 * 1) This is the only choice (i.e. no active key) or;
+	 * 2) Peer has switched to this key (unicast only) or;
+	 * 3) It is time to do a pending key probe;
+	 */
+	if (unlikely(key.pending)) {
+		tx_key = key.pending;
+		if (!key.active)
+			goto encrypt;
+		if (__rx && atomic_read(&__rx->peer_rx_active) == tx_key)
+			goto encrypt;
+		if (TIPC_SKB_CB(*skb)->probe)
+			goto encrypt;
+		if (!__rx &&
+		    time_after(jiffies, tx->timer2 + TIPC_TX_PROBE_LIM)) {
+			tx->timer2 = jiffies;
+			probe = skb_clone(*skb, GFP_ATOMIC);
+			if (probe) {
+				TIPC_SKB_CB(probe)->probe = 1;
+				tipc_crypto_xmit(net, &probe, b, dst, __dnode);
+				if (probe)
+					b->media->send_msg(net, probe, b, dst);
+			}
+		}
+	}
+	/* Else, use the active key if any */
+	if (likely(key.active)) {
+		tx_key = key.active;
+		goto encrypt;
+	}
+	goto exit;
+
+encrypt:
+	aead = tipc_aead_get(tx->aead[tx_key]);
+	if (unlikely(!aead))
+		goto exit;
+	rc = tipc_ehdr_build(net, aead, tx_key, *skb, __rx);
+	if (likely(rc > 0))
+		rc = tipc_aead_encrypt(aead, *skb, b, dst, __dnode);
+
+exit:
+	switch (rc) {
+	case 0:
+		this_cpu_inc(stats->stat[STAT_OK]);
+		break;
+	case -EINPROGRESS:
+	case -EBUSY:
+		this_cpu_inc(stats->stat[STAT_ASYNC]);
+		*skb = NULL;
+		return rc;
+	default:
+		this_cpu_inc(stats->stat[STAT_NOK]);
+		if (rc == -ENOKEY)
+			this_cpu_inc(stats->stat[STAT_NOKEYS]);
+		else if (rc == -EKEYREVOKED)
+			this_cpu_inc(stats->stat[STAT_BADKEYS]);
+		kfree_skb(*skb);
+		*skb = NULL;
+		break;
+	}
+
+	tipc_aead_put(aead);
+	return rc;
+}
+
+/**
+ * tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer
+ * @net: struct net
+ * @rx: RX crypto handle
+ * @skb: input/output message skb pointer
+ * @b: bearer where the message has been received
+ *
+ * If the decryption is successful, the decrypted skb is returned directly or
+ * as the callback, the encryption header and auth tag will be trimed out
+ * before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete().
+ * Otherwise, the skb will be freed!
+ * Note: RX key(s) can be re-aligned, or in case of no key suitable, TX
+ * cluster key(s) can be taken for decryption (- recursive).
+ *
+ * Return:
+ * 0                   : the decryption has successfully completed
+ * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made
+ * -ENOKEY             : the decryption has failed due to no key
+ * -EBADMSG            : the decryption has failed due to bad message
+ * -ENOMEM             : the decryption has failed due to no memory
+ * < 0                 : the decryption has failed due to other reasons
+ */
+int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
+		    struct sk_buff **skb, struct tipc_bearer *b)
+{
+	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
+	struct tipc_crypto_stats __percpu *stats;
+	struct tipc_aead *aead = NULL;
+	struct tipc_key key;
+	int rc = -ENOKEY;
+	u8 tx_key = 0;
+
+	/* New peer?
+	 * Let's try with TX key (i.e. cluster mode) & verify the skb first!
+	 */
+	if (unlikely(!rx))
+		goto pick_tx;
+
+	/* Pick RX key according to TX key, three cases are possible:
+	 * 1) The current active key (likely) or;
+	 * 2) The pending (new or deactivated) key (if any) or;
+	 * 3) The passive or old active key (i.e. users > 0);
+	 */
+	tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key;
+	key = rx->key;
+	if (likely(tx_key == key.active))
+		goto decrypt;
+	if (tx_key == key.pending)
+		goto decrypt;
+	if (tx_key == key.passive) {
+		rx->timer2 = jiffies;
+		if (tipc_aead_users(rx->aead[key.passive]) > 0)
+			goto decrypt;
+	}
+
+	/* Unknown key, let's try to align RX key(s) */
+	if (tipc_crypto_key_try_align(rx, tx_key))
+		goto decrypt;
+
+pick_tx:
+	/* No key suitable? Try to pick one from TX... */
+	aead = tipc_crypto_key_pick_tx(tx, rx, *skb);
+	if (aead)
+		goto decrypt;
+	goto exit;
+
+decrypt:
+	rcu_read_lock();
+	if (!aead)
+		aead = tipc_aead_get(rx->aead[tx_key]);
+	rc = tipc_aead_decrypt(net, aead, *skb, b);
+	rcu_read_unlock();
+
+exit:
+	stats = ((rx) ?: tx)->stats;
+	switch (rc) {
+	case 0:
+		this_cpu_inc(stats->stat[STAT_OK]);
+		break;
+	case -EINPROGRESS:
+	case -EBUSY:
+		this_cpu_inc(stats->stat[STAT_ASYNC]);
+		*skb = NULL;
+		return rc;
+	default:
+		this_cpu_inc(stats->stat[STAT_NOK]);
+		if (rc == -ENOKEY) {
+			kfree_skb(*skb);
+			*skb = NULL;
+			if (rx)
+				tipc_node_put(rx->node);
+			this_cpu_inc(stats->stat[STAT_NOKEYS]);
+			return rc;
+		} else if (rc == -EBADMSG) {
+			this_cpu_inc(stats->stat[STAT_BADMSGS]);
+		}
+		break;
+	}
+
+	tipc_crypto_rcv_complete(net, aead, b, skb, rc);
+	return rc;
+}
+
+static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
+				     struct tipc_bearer *b,
+				     struct sk_buff **skb, int err)
+{
+	struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb);
+	struct tipc_crypto *rx = aead->crypto;
+	struct tipc_aead *tmp = NULL;
+	struct tipc_ehdr *ehdr;
+	struct tipc_node *n;
+	u8 rx_key_active;
+	bool destined;
+
+	/* Is this completed by TX? */
+	if (unlikely(!rx->node)) {
+		rx = skb_cb->tx_clone_ctx.rx;
+#ifdef TIPC_CRYPTO_DEBUG
+		pr_info("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n",
+			(rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead,
+			(*skb)->next, skb_cb->flags);
+		pr_info("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n",
+			skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last,
+			aead->crypto->aead[1], aead->crypto->aead[2],
+			aead->crypto->aead[3]);
+#endif
+		if (unlikely(err)) {
+			if (err == -EBADMSG && (*skb)->next)
+				tipc_rcv(net, (*skb)->next, b);
+			goto free_skb;
+		}
+
+		if (likely((*skb)->next)) {
+			kfree_skb((*skb)->next);
+			(*skb)->next = NULL;
+		}
+		ehdr = (struct tipc_ehdr *)(*skb)->data;
+		if (!rx) {
+			WARN_ON(ehdr->user != LINK_CONFIG);
+			n = tipc_node_create(net, 0, ehdr->id, 0xffffu, 0,
+					     true);
+			rx = tipc_node_crypto_rx(n);
+			if (unlikely(!rx))
+				goto free_skb;
+		}
+
+		/* Skip cloning this time as we had a RX pending key */
+		if (rx->key.pending)
+			goto rcv;
+		if (tipc_aead_clone(&tmp, aead) < 0)
+			goto rcv;
+		if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key) < 0) {
+			tipc_aead_free(&tmp->rcu);
+			goto rcv;
+		}
+		tipc_aead_put(aead);
+		aead = tipc_aead_get(tmp);
+	}
+
+	if (unlikely(err)) {
+		tipc_aead_users_dec(aead, INT_MIN);
+		goto free_skb;
+	}
+
+	/* Set the RX key's user */
+	tipc_aead_users_set(aead, 1);
+
+rcv:
+	/* Mark this point, RX works */
+	rx->timer1 = jiffies;
+
+	/* Remove ehdr & auth. tag prior to tipc_rcv() */
+	ehdr = (struct tipc_ehdr *)(*skb)->data;
+	destined = ehdr->destined;
+	rx_key_active = ehdr->rx_key_active;
+	skb_pull(*skb, tipc_ehdr_size(ehdr));
+	pskb_trim(*skb, (*skb)->len - aead->authsize);
+
+	/* Validate TIPCv2 message */
+	if (unlikely(!tipc_msg_validate(skb))) {
+		pr_err_ratelimited("Packet dropped after decryption!\n");
+		goto free_skb;
+	}
+
+	/* Update peer RX active key & TX users */
+	if (destined)
+		tipc_crypto_key_synch(rx, rx_key_active, buf_msg(*skb));
+
+	/* Mark skb decrypted */
+	skb_cb->decrypted = 1;
+
+	/* Clear clone cxt if any */
+	if (likely(!skb_cb->tx_clone_deferred))
+		goto exit;
+	skb_cb->tx_clone_deferred = 0;
+	memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
+	goto exit;
+
+free_skb:
+	kfree_skb(*skb);
+	*skb = NULL;
+
+exit:
+	tipc_aead_put(aead);
+	if (rx)
+		tipc_node_put(rx->node);
+}
+
+static void tipc_crypto_do_cmd(struct net *net, int cmd)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_crypto *tx = tn->crypto_tx, *rx;
+	struct list_head *p;
+	unsigned int stat;
+	int i, j, cpu;
+	char buf[200];
+
+	/* Currently only one command is supported */
+	switch (cmd) {
+	case 0xfff1:
+		goto print_stats;
+	default:
+		return;
+	}
+
+print_stats:
+	/* Print a header */
+	pr_info("\n=============== TIPC Crypto Statistics ===============\n\n");
+
+	/* Print key status */
+	pr_info("Key status:\n");
+	pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net),
+		tipc_crypto_key_dump(tx, buf));
+
+	rcu_read_lock();
+	for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
+		rx = tipc_node_crypto_rx_by_list(p);
+		pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node),
+			tipc_crypto_key_dump(rx, buf));
+	}
+	rcu_read_unlock();
+
+	/* Print crypto statistics */
+	for (i = 0, j = 0; i < MAX_STATS; i++)
+		j += scnprintf(buf + j, 200 - j, "|%11s ", hstats[i]);
+	pr_info("\nCounter     %s", buf);
+
+	memset(buf, '-', 115);
+	buf[115] = '\0';
+	pr_info("%s\n", buf);
+
+	j = scnprintf(buf, 200, "TX(%7.7s) ", tipc_own_id_string(net));
+	for_each_possible_cpu(cpu) {
+		for (i = 0; i < MAX_STATS; i++) {
+			stat = per_cpu_ptr(tx->stats, cpu)->stat[i];
+			j += scnprintf(buf + j, 200 - j, "|%11d ", stat);
+		}
+		pr_info("%s", buf);
+		j = scnprintf(buf, 200, "%12s", " ");
+	}
+
+	rcu_read_lock();
+	for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
+		rx = tipc_node_crypto_rx_by_list(p);
+		j = scnprintf(buf, 200, "RX(%7.7s) ",
+			      tipc_node_get_id_str(rx->node));
+		for_each_possible_cpu(cpu) {
+			for (i = 0; i < MAX_STATS; i++) {
+				stat = per_cpu_ptr(rx->stats, cpu)->stat[i];
+				j += scnprintf(buf + j, 200 - j, "|%11d ",
+					       stat);
+			}
+			pr_info("%s", buf);
+			j = scnprintf(buf, 200, "%12s", " ");
+		}
+	}
+	rcu_read_unlock();
+
+	pr_info("\n======================== Done ========================\n");
+}
+
+static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf)
+{
+	struct tipc_key key = c->key;
+	struct tipc_aead *aead;
+	int k, i = 0;
+	char *s;
+
+	for (k = KEY_MIN; k <= KEY_MAX; k++) {
+		if (k == key.passive)
+			s = "PAS";
+		else if (k == key.active)
+			s = "ACT";
+		else if (k == key.pending)
+			s = "PEN";
+		else
+			s = "-";
+		i += scnprintf(buf + i, 200 - i, "\tKey%d: %s", k, s);
+
+		rcu_read_lock();
+		aead = rcu_dereference(c->aead[k]);
+		if (aead)
+			i += scnprintf(buf + i, 200 - i,
+				       "{\"%s...\", \"%s\"}/%d:%d",
+				       aead->hint,
+				       (aead->mode == CLUSTER_KEY) ? "c" : "p",
+				       atomic_read(&aead->users),
+				       refcount_read(&aead->refcnt));
+		rcu_read_unlock();
+		i += scnprintf(buf + i, 200 - i, "\n");
+	}
+
+	if (c->node)
+		i += scnprintf(buf + i, 200 - i, "\tPeer RX active: %d\n",
+			       atomic_read(&c->peer_rx_active));
+
+	return buf;
+}
+
+#ifdef TIPC_CRYPTO_DEBUG
+static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
+				  char *buf)
+{
+	struct tipc_key *key = &old;
+	int k, i = 0;
+	char *s;
+
+	/* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */
+again:
+	i += scnprintf(buf + i, 32 - i, "[");
+	for (k = KEY_MIN; k <= KEY_MAX; k++) {
+		if (k == key->passive)
+			s = "pas";
+		else if (k == key->active)
+			s = "act";
+		else if (k == key->pending)
+			s = "pen";
+		else
+			s = "-";
+		i += scnprintf(buf + i, 32 - i,
+			       (k != KEY_MAX) ? "%s " : "%s", s);
+	}
+	if (key != &new) {
+		i += scnprintf(buf + i, 32 - i, "] -> ");
+		key = &new;
+		goto again;
+	}
+	i += scnprintf(buf + i, 32 - i, "]");
+	return buf;
+}
+#endif
diff --git a/net/tipc/crypto.h b/net/tipc/crypto.h
new file mode 100644
index 000000000000..c3de769f49e8
--- /dev/null
+++ b/net/tipc/crypto.h
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * net/tipc/crypto.h: Include file for TIPC crypto
+ *
+ * Copyright (c) 2019, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifdef CONFIG_TIPC_CRYPTO
+#ifndef _TIPC_CRYPTO_H
+#define _TIPC_CRYPTO_H
+
+#include "core.h"
+#include "node.h"
+#include "msg.h"
+#include "bearer.h"
+
+#define TIPC_EVERSION			7
+
+/* AEAD aes(gcm) */
+#define TIPC_AES_GCM_KEY_SIZE_128	16
+#define TIPC_AES_GCM_KEY_SIZE_192	24
+#define TIPC_AES_GCM_KEY_SIZE_256	32
+
+#define TIPC_AES_GCM_SALT_SIZE		4
+#define TIPC_AES_GCM_IV_SIZE		12
+#define TIPC_AES_GCM_TAG_SIZE		16
+
+/**
+ * TIPC crypto modes:
+ * - CLUSTER_KEY:
+ *	One single key is used for both TX & RX in all nodes in the cluster.
+ * - PER_NODE_KEY:
+ *	Each nodes in the cluster has one TX key, for RX a node needs to know
+ *	its peers' TX key for the decryption of messages from those nodes.
+ */
+enum {
+	CLUSTER_KEY = 1,
+	PER_NODE_KEY = (1 << 1),
+};
+
+extern int sysctl_tipc_max_tfms __read_mostly;
+
+/**
+ * TIPC encryption message format:
+ *
+ *     3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
+ *     1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * w0:|Ver=7| User  |D|TX |RX |K|                 Rsvd                |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * w1:|                             Seqno                             |
+ * w2:|                           (8 octets)                          |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * w3:\                            Prevnode                           \
+ *    /                        (4 or 16 octets)                       /
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    \                                                               \
+ *    /       Encrypted complete TIPC V2 header and user data         /
+ *    \                                                               \
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    |                                                               |
+ *    |                             AuthTag                           |
+ *    |                           (16 octets)                         |
+ *    |                                                               |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Word0:
+ *	Ver	: = 7 i.e. TIPC encryption message version
+ *	User	: = 7 (for LINK_PROTOCOL); = 13 (for LINK_CONFIG) or = 0
+ *	D	: The destined bit i.e. the message's destination node is
+ *	          "known" or not at the message encryption
+ *	TX	: TX key used for the message encryption
+ *	RX	: Currently RX active key corresponding to the destination
+ *	          node's TX key (when the "D" bit is set)
+ *	K	: Keep-alive bit (for RPS, LINK_PROTOCOL/STATE_MSG only)
+ *	Rsvd	: Reserved bit, field
+ * Word1-2:
+ *	Seqno	: The 64-bit sequence number of the encrypted message, also
+ *		  part of the nonce used for the message encryption/decryption
+ * Word3-:
+ *	Prevnode: The source node address, or ID in case LINK_CONFIG only
+ *	AuthTag	: The authentication tag for the message integrity checking
+ *		  generated by the message encryption
+ */
+struct tipc_ehdr {
+	union {
+		struct {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+			__u8	destined:1,
+				user:4,
+				version:3;
+			__u8	reserved_1:3,
+				keepalive:1,
+				rx_key_active:2,
+				tx_key:2;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+			__u8	version:3,
+				user:4,
+				destined:1;
+			__u8	tx_key:2,
+				rx_key_active:2,
+				keepalive:1,
+				reserved_1:3;
+#else
+#error  "Please fix <asm/byteorder.h>"
+#endif
+			__be16	reserved_2;
+		} __packed;
+		__be32 w0;
+	};
+	__be64 seqno;
+	union {
+		__be32 addr;
+		__u8 id[NODE_ID_LEN]; /* For a LINK_CONFIG message only! */
+	};
+#define EHDR_SIZE	(offsetof(struct tipc_ehdr, addr) + sizeof(__be32))
+#define EHDR_CFG_SIZE	(sizeof(struct tipc_ehdr))
+#define EHDR_MIN_SIZE	(EHDR_SIZE)
+#define EHDR_MAX_SIZE	(EHDR_CFG_SIZE)
+#define EMSG_OVERHEAD	(EHDR_SIZE + TIPC_AES_GCM_TAG_SIZE)
+} __packed;
+
+int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
+		      struct tipc_node *node);
+void tipc_crypto_stop(struct tipc_crypto **crypto);
+void tipc_crypto_timeout(struct tipc_crypto *rx);
+int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
+		     struct tipc_bearer *b, struct tipc_media_addr *dst,
+		     struct tipc_node *__dnode);
+int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
+		    struct sk_buff **skb, struct tipc_bearer *b);
+int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
+			 u8 mode);
+void tipc_crypto_key_flush(struct tipc_crypto *c);
+int tipc_aead_key_validate(struct tipc_aead_key *ukey);
+bool tipc_ehdr_validate(struct sk_buff *skb);
+
+#endif /* _TIPC_CRYPTO_H */
+#endif
diff --git a/net/tipc/link.c b/net/tipc/link.c
index e7bb4cbb7716..fb72031228c9 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -44,6 +44,7 @@
 #include "netlink.h"
 #include "monitor.h"
 #include "trace.h"
+#include "crypto.h"
 
 #include <linux/pkt_sched.h>
 
@@ -397,6 +398,15 @@ int tipc_link_mtu(struct tipc_link *l)
 	return l->mtu;
 }
 
+int tipc_link_mss(struct tipc_link *l)
+{
+#ifdef CONFIG_TIPC_CRYPTO
+	return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
+#else
+	return l->mtu - INT_H_SIZE;
+#endif
+}
+
 u16 tipc_link_rcv_nxt(struct tipc_link *l)
 {
 	return l->rcv_nxt;
@@ -948,6 +958,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 	u16 seqno = l->snd_nxt;
 	int pkt_cnt = skb_queue_len(list);
 	int imp = msg_importance(hdr);
+	unsigned int mss = tipc_link_mss(l);
 	unsigned int maxwin = l->window;
 	unsigned int mtu = l->mtu;
 	bool new_bundle;
@@ -1000,8 +1011,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 			continue;
 		}
 		if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
-					mtu - INT_H_SIZE, l->addr,
-					&new_bundle)) {
+					mss, l->addr, &new_bundle)) {
 			if (skb) {
 				/* Keep a ref. to the skb for next try */
 				l->backlog[imp].target_bskb = skb;
@@ -1154,7 +1164,7 @@ static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
 		if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
 			continue;
 		TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
-		_skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, GFP_ATOMIC);
+		_skb = pskb_copy(skb, GFP_ATOMIC);
 		if (!_skb)
 			return 0;
 		hdr = buf_msg(_skb);
@@ -1430,8 +1440,7 @@ static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
 			if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
 				continue;
 			TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
-			_skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE,
-					   GFP_ATOMIC);
+			_skb = pskb_copy(skb, GFP_ATOMIC);
 			if (!_skb)
 				continue;
 			hdr = buf_msg(_skb);
diff --git a/net/tipc/link.h b/net/tipc/link.h
index adcad65e761c..c09e9d49d0a3 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -141,6 +141,7 @@ void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 int tipc_link_bc_peers(struct tipc_link *l);
 void tipc_link_set_mtu(struct tipc_link *l, int mtu);
 int tipc_link_mtu(struct tipc_link *l);
+int tipc_link_mss(struct tipc_link *l);
 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
 			  struct sk_buff_head *xmitq);
 void tipc_link_build_bc_sync_msg(struct tipc_link *l,
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index acb7be592fb1..0d515d20b056 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -39,10 +39,16 @@
 #include "msg.h"
 #include "addr.h"
 #include "name_table.h"
+#include "crypto.h"
 
 #define MAX_FORWARD_SIZE 1024
+#ifdef CONFIG_TIPC_CRYPTO
+#define BUF_HEADROOM ALIGN(((LL_MAX_HEADER + 48) + EHDR_MAX_SIZE), 16)
+#define BUF_TAILROOM (TIPC_AES_GCM_TAG_SIZE)
+#else
 #define BUF_HEADROOM (LL_MAX_HEADER + 48)
 #define BUF_TAILROOM 16
+#endif
 
 static unsigned int align(unsigned int i)
 {
@@ -61,7 +67,11 @@ static unsigned int align(unsigned int i)
 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
 {
 	struct sk_buff *skb;
+#ifdef CONFIG_TIPC_CRYPTO
+	unsigned int buf_size = (BUF_HEADROOM + size + BUF_TAILROOM + 3) & ~3u;
+#else
 	unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
+#endif
 
 	skb = alloc_skb_fclone(buf_size, gfp);
 	if (skb) {
@@ -173,7 +183,7 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
 	}
 
 	if (fragid == LAST_FRAGMENT) {
-		TIPC_SKB_CB(head)->validated = false;
+		TIPC_SKB_CB(head)->validated = 0;
 		if (unlikely(!tipc_msg_validate(&head)))
 			goto err;
 		*buf = head;
@@ -271,6 +281,7 @@ bool tipc_msg_validate(struct sk_buff **_skb)
 
 	if (unlikely(TIPC_SKB_CB(skb)->validated))
 		return true;
+
 	if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
 		return false;
 
@@ -292,7 +303,7 @@ bool tipc_msg_validate(struct sk_buff **_skb)
 	if (unlikely(skb->len < msz))
 		return false;
 
-	TIPC_SKB_CB(skb)->validated = true;
+	TIPC_SKB_CB(skb)->validated = 1;
 	return true;
 }
 
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 14697e6c995e..6d466ebdb64f 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -102,16 +102,42 @@ struct plist;
 #define TIPC_MEDIA_INFO_OFFSET	5
 
 struct tipc_skb_cb {
-	struct sk_buff *tail;
-	unsigned long nxt_retr;
-	unsigned long retr_stamp;
-	u32 bytes_read;
-	u32 orig_member;
-	u16 chain_imp;
-	u16 ackers;
-	u16 retr_cnt;
-	bool validated;
-};
+	union {
+		struct {
+			struct sk_buff *tail;
+			unsigned long nxt_retr;
+			unsigned long retr_stamp;
+			u32 bytes_read;
+			u32 orig_member;
+			u16 chain_imp;
+			u16 ackers;
+			u16 retr_cnt;
+		} __packed;
+#ifdef CONFIG_TIPC_CRYPTO
+		struct {
+			struct tipc_crypto *rx;
+			struct tipc_aead *last;
+			u8 recurs;
+		} tx_clone_ctx __packed;
+#endif
+	} __packed;
+	union {
+		struct {
+			u8 validated:1;
+#ifdef CONFIG_TIPC_CRYPTO
+			u8 encrypted:1;
+			u8 decrypted:1;
+			u8 probe:1;
+			u8 tx_clone_deferred:1;
+#endif
+		};
+		u8 flags;
+	};
+	u8 reserved;
+#ifdef CONFIG_TIPC_CRYPTO
+	void *crypto_ctx;
+#endif
+} __packed;
 
 #define TIPC_SKB_CB(__skb) ((struct tipc_skb_cb *)&((__skb)->cb[0]))
 
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 43d12a630f34..d8bf2c179562 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -44,6 +44,7 @@
 #include "discover.h"
 #include "netlink.h"
 #include "trace.h"
+#include "crypto.h"
 
 #define INVALID_NODE_SIG	0x10000
 #define NODE_CLEANUP_AFTER	300000
@@ -100,6 +101,7 @@ struct tipc_bclink_entry {
  * @publ_list: list of publications
  * @rcu: rcu struct for tipc_node
  * @delete_at: indicates the time for deleting a down node
+ * @crypto_rx: RX crypto handler
  */
 struct tipc_node {
 	u32 addr;
@@ -131,6 +133,9 @@ struct tipc_node {
 	unsigned long delete_at;
 	struct net *peer_net;
 	u32 peer_hash_mix;
+#ifdef CONFIG_TIPC_CRYPTO
+	struct tipc_crypto *crypto_rx;
+#endif
 };
 
 /* Node FSM states and events:
@@ -168,7 +173,6 @@ static void tipc_node_timeout(struct timer_list *t);
 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
-static void tipc_node_put(struct tipc_node *node);
 static bool node_is_up(struct tipc_node *n);
 static void tipc_node_delete_from_list(struct tipc_node *node);
 
@@ -258,15 +262,41 @@ char *tipc_node_get_id_str(struct tipc_node *node)
 	return node->peer_id_string;
 }
 
+#ifdef CONFIG_TIPC_CRYPTO
+/**
+ * tipc_node_crypto_rx - Retrieve crypto RX handle from node
+ * Note: node ref counter must be held first!
+ */
+struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n)
+{
+	return (__n) ? __n->crypto_rx : NULL;
+}
+
+struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos)
+{
+	return container_of(pos, struct tipc_node, list)->crypto_rx;
+}
+#endif
+
+void tipc_node_free(struct rcu_head *rp)
+{
+	struct tipc_node *n = container_of(rp, struct tipc_node, rcu);
+
+#ifdef CONFIG_TIPC_CRYPTO
+	tipc_crypto_stop(&n->crypto_rx);
+#endif
+	kfree(n);
+}
+
 static void tipc_node_kref_release(struct kref *kref)
 {
 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
 
 	kfree(n->bc_entry.link);
-	kfree_rcu(n, rcu);
+	call_rcu(&n->rcu, tipc_node_free);
 }
 
-static void tipc_node_put(struct tipc_node *node)
+void tipc_node_put(struct tipc_node *node)
 {
 	kref_put(&node->kref, tipc_node_kref_release);
 }
@@ -411,9 +441,9 @@ static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
 	}
 }
 
-static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
-					  u8 *peer_id, u16 capabilities,
-					  u32 hash_mixes, bool preliminary)
+struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
+				   u16 capabilities, u32 hash_mixes,
+				   bool preliminary)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_node *n, *temp_node;
@@ -474,6 +504,14 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 		goto exit;
 	}
 	tipc_nodeid2string(n->peer_id_string, peer_id);
+#ifdef CONFIG_TIPC_CRYPTO
+	if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
+		pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
+		kfree(n);
+		n = NULL;
+		goto exit;
+	}
+#endif
 	n->addr = addr;
 	n->preliminary = preliminary;
 	memcpy(&n->peer_id, peer_id, 16);
@@ -725,6 +763,10 @@ static void tipc_node_timeout(struct timer_list *t)
 		return;
 	}
 
+#ifdef CONFIG_TIPC_CRYPTO
+	/* Take any crypto key related actions first */
+	tipc_crypto_timeout(n->crypto_rx);
+#endif
 	__skb_queue_head_init(&xmitq);
 
 	/* Initial node interval to value larger (10 seconds), then it will be
@@ -745,7 +787,7 @@ static void tipc_node_timeout(struct timer_list *t)
 			remains--;
 		}
 		tipc_node_read_unlock(n);
-		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
+		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr, n);
 		if (rc & TIPC_LINK_DOWN_EVT)
 			tipc_node_link_down(n, bearer_id, false);
 	}
@@ -777,7 +819,7 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
 	n->link_id = tipc_link_id(nl);
 
 	/* Leave room for tunnel header when returning 'mtu' to users: */
-	n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
+	n->links[bearer_id].mtu = tipc_link_mss(nl);
 
 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
@@ -831,7 +873,7 @@ static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
 	tipc_node_write_lock(n);
 	__tipc_node_link_up(n, bearer_id, xmitq);
 	maddr = &n->links[bearer_id].maddr;
-	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
+	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr, n);
 	tipc_node_write_unlock(n);
 }
 
@@ -986,7 +1028,7 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 	if (delete)
 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
 	if (!skb_queue_empty(&xmitq))
-		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
+		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr, n);
 	tipc_sk_rcv(n->net, &le->inputq);
 }
 
@@ -1640,7 +1682,7 @@ int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
 	if (unlikely(rc == -ENOBUFS))
 		tipc_node_link_down(n, bearer_id, false);
 	else
-		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
 
 	tipc_node_put(n);
 
@@ -1788,7 +1830,7 @@ static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id
 	}
 
 	if (!skb_queue_empty(&xmitq))
-		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
 
 	if (!skb_queue_empty(&be->inputq1))
 		tipc_node_mcast_rcv(n);
@@ -1966,20 +2008,38 @@ static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 {
 	struct sk_buff_head xmitq;
-	struct tipc_node *n;
+	struct tipc_link_entry *le;
 	struct tipc_msg *hdr;
+	struct tipc_node *n;
 	int bearer_id = b->identity;
-	struct tipc_link_entry *le;
 	u32 self = tipc_own_addr(net);
 	int usr, rc = 0;
 	u16 bc_ack;
+#ifdef CONFIG_TIPC_CRYPTO
+	struct tipc_ehdr *ehdr;
 
-	__skb_queue_head_init(&xmitq);
+	/* Check if message must be decrypted first */
+	if (TIPC_SKB_CB(skb)->decrypted || !tipc_ehdr_validate(skb))
+		goto rcv;
 
+	ehdr = (struct tipc_ehdr *)skb->data;
+	if (likely(ehdr->user != LINK_CONFIG)) {
+		n = tipc_node_find(net, ntohl(ehdr->addr));
+		if (unlikely(!n))
+			goto discard;
+	} else {
+		n = tipc_node_find_by_id(net, ehdr->id);
+	}
+	tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
+	if (!skb)
+		return;
+
+rcv:
+#endif
 	/* Ensure message is well-formed before touching the header */
-	TIPC_SKB_CB(skb)->validated = false;
 	if (unlikely(!tipc_msg_validate(&skb)))
 		goto discard;
+	__skb_queue_head_init(&xmitq);
 	hdr = buf_msg(skb);
 	usr = msg_user(hdr);
 	bc_ack = msg_bcast_ack(hdr);
@@ -2050,7 +2110,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 		tipc_sk_rcv(net, &le->inputq);
 
 	if (!skb_queue_empty(&xmitq))
-		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
 
 	tipc_node_put(n);
 discard:
@@ -2081,7 +2141,7 @@ void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
 				tipc_link_set_mtu(e->link, b->mtu);
 		}
 		tipc_node_write_unlock(n);
-		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
 	}
 
 	rcu_read_unlock();
@@ -2323,7 +2383,8 @@ int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
 
 out:
 	tipc_node_read_unlock(node);
-	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
+	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
+			 NULL);
 	return res;
 }
 
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 50f8838b32c2..1a15cf82cb11 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -76,6 +76,14 @@ void tipc_node_stop(struct net *net);
 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id);
 u32 tipc_node_get_addr(struct tipc_node *node);
 char *tipc_node_get_id_str(struct tipc_node *node);
+void tipc_node_put(struct tipc_node *node);
+struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
+				   u16 capabilities, u32 hash_mixes,
+				   bool preliminary);
+#ifdef CONFIG_TIPC_CRYPTO
+struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n);
+struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos);
+#endif
 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr);
 void tipc_node_check_dest(struct net *net, u32 onode, u8 *peer_id128,
 			  struct tipc_bearer *bearer,
diff --git a/net/tipc/sysctl.c b/net/tipc/sysctl.c
index 6159d327db76..58ab3d6dcdce 100644
--- a/net/tipc/sysctl.c
+++ b/net/tipc/sysctl.c
@@ -35,6 +35,7 @@
 
 #include "core.h"
 #include "trace.h"
+#include "crypto.h"
 
 #include <linux/sysctl.h>
 
@@ -64,6 +65,16 @@ static struct ctl_table tipc_table[] = {
 		.mode           = 0644,
 		.proc_handler   = proc_doulongvec_minmax,
 	},
+#ifdef CONFIG_TIPC_CRYPTO
+	{
+		.procname	= "max_tfms",
+		.data		= &sysctl_tipc_max_tfms,
+		.maxlen		= sizeof(sysctl_tipc_max_tfms),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1         = SYSCTL_ONE,
+	},
+#endif
 	{}
 };
 
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 43ca5fd6574d..86aaa4d3e781 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -372,6 +372,7 @@ static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 		goto out;
 
 	if (b && test_bit(0, &b->up)) {
+		TIPC_SKB_CB(skb)->flags = 0;
 		tipc_rcv(sock_net(sk), skb, b);
 		return 0;
 	}
-- 
2.13.7

[net-next v2 5/5] tipc: add support for AEAD key setting via netlink

[Tuong Lien]

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: Ying Xue <ying.xue@windreiver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
---
 include/uapi/linux/tipc_netlink.h |   4 ++
 net/tipc/netlink.c                |  18 ++++-
 net/tipc/node.c                   | 135 ++++++++++++++++++++++++++++++++++++++
 net/tipc/node.h                   |   4 ++
 4 files changed, 160 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index efb958fd167d..6c2194ab745b 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -63,6 +63,8 @@ enum {
 	TIPC_NL_PEER_REMOVE,
 	TIPC_NL_BEARER_ADD,
 	TIPC_NL_UDP_GET_REMOTEIP,
+	TIPC_NL_KEY_SET,
+	TIPC_NL_KEY_FLUSH,
 
 	__TIPC_NL_CMD_MAX,
 	TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
@@ -160,6 +162,8 @@ enum {
 	TIPC_NLA_NODE_UNSPEC,
 	TIPC_NLA_NODE_ADDR,		/* u32 */
 	TIPC_NLA_NODE_UP,		/* flag */
+	TIPC_NLA_NODE_ID,		/* data */
+	TIPC_NLA_NODE_KEY,		/* data */
 
 	__TIPC_NLA_NODE_MAX,
 	TIPC_NLA_NODE_MAX = __TIPC_NLA_NODE_MAX - 1
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index d32bbd0f5e46..e53231bd23b4 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -102,7 +102,11 @@ const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
 const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = {
 	[TIPC_NLA_NODE_UNSPEC]		= { .type = NLA_UNSPEC },
 	[TIPC_NLA_NODE_ADDR]		= { .type = NLA_U32 },
-	[TIPC_NLA_NODE_UP]		= { .type = NLA_FLAG }
+	[TIPC_NLA_NODE_UP]		= { .type = NLA_FLAG },
+	[TIPC_NLA_NODE_ID]		= { .type = NLA_BINARY,
+					    .len = TIPC_NODEID_LEN},
+	[TIPC_NLA_NODE_KEY]		= { .type = NLA_BINARY,
+					    .len = TIPC_AEAD_KEY_SIZE_MAX},
 };
 
 /* Properties valid for media, bearer and link */
@@ -257,6 +261,18 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 		.dumpit	= tipc_udp_nl_dump_remoteip,
 	},
 #endif
+#ifdef CONFIG_TIPC_CRYPTO
+	{
+		.cmd	= TIPC_NL_KEY_SET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit	= tipc_nl_node_set_key,
+	},
+	{
+		.cmd	= TIPC_NL_KEY_FLUSH,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit	= tipc_nl_node_flush_key,
+	},
+#endif
 };
 
 struct genl_family tipc_genl_family __ro_after_init = {
diff --git a/net/tipc/node.c b/net/tipc/node.c
index d8bf2c179562..aaf595613e6e 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -2760,6 +2760,141 @@ int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
 	return skb->len;
 }
 
+#ifdef CONFIG_TIPC_CRYPTO
+static int tipc_nl_retrieve_key(struct nlattr **attrs,
+				struct tipc_aead_key **key)
+{
+	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
+
+	if (!attr)
+		return -ENODATA;
+
+	*key = (struct tipc_aead_key *)nla_data(attr);
+	if (nla_len(attr) < tipc_aead_key_size(*key))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
+{
+	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
+
+	if (!attr)
+		return -ENODATA;
+
+	if (nla_len(attr) < TIPC_NODEID_LEN)
+		return -EINVAL;
+
+	*node_id = (u8 *)nla_data(attr);
+	return 0;
+}
+
+int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *n = NULL;
+	struct tipc_aead_key *ukey;
+	struct tipc_crypto *c;
+	u8 *id, *own_id;
+	int rc = 0;
+
+	if (!info->attrs[TIPC_NLA_NODE])
+		return -EINVAL;
+
+	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
+			      info->attrs[TIPC_NLA_NODE],
+			      tipc_nl_node_policy, info->extack);
+	if (rc)
+		goto exit;
+
+	own_id = tipc_own_id(net);
+	if (!own_id) {
+		rc = -EPERM;
+		goto exit;
+	}
+
+	rc = tipc_nl_retrieve_key(attrs, &ukey);
+	if (rc)
+		goto exit;
+
+	rc = tipc_aead_key_validate(ukey);
+	if (rc)
+		goto exit;
+
+	rc = tipc_nl_retrieve_nodeid(attrs, &id);
+	switch (rc) {
+	case -ENODATA:
+		/* Cluster key mode */
+		rc = tipc_crypto_key_init(tn->crypto_tx, ukey, CLUSTER_KEY);
+		break;
+	case 0:
+		/* Per-node key mode */
+		if (!memcmp(id, own_id, NODE_ID_LEN)) {
+			c = tn->crypto_tx;
+		} else {
+			n = tipc_node_find_by_id(net, id) ?:
+				tipc_node_create(net, 0, id, 0xffffu, 0, true);
+			if (unlikely(!n)) {
+				rc = -ENOMEM;
+				break;
+			}
+			c = n->crypto_rx;
+		}
+
+		rc = tipc_crypto_key_init(c, ukey, PER_NODE_KEY);
+		if (n)
+			tipc_node_put(n);
+		break;
+	default:
+		break;
+	}
+
+exit:
+	return (rc < 0) ? rc : 0;
+}
+
+int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_node_set_key(skb, info);
+	rtnl_unlock();
+
+	return err;
+}
+
+int __tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *n;
+
+	tipc_crypto_key_flush(tn->crypto_tx);
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, &tn->node_list, list)
+		tipc_crypto_key_flush(n->crypto_rx);
+	rcu_read_unlock();
+
+	pr_info("All keys are flushed!\n");
+	return 0;
+}
+
+int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_node_flush_key(skb, info);
+	rtnl_unlock();
+
+	return err;
+}
+#endif
+
 /**
  * tipc_node_dump - dump TIPC node data
  * @n: tipc node to be dumped
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 1a15cf82cb11..a6803b449a2c 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -119,5 +119,9 @@ int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
 				   struct netlink_callback *cb);
+#ifdef CONFIG_TIPC_CRYPTO
+int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info);
+int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info);
+#endif
 void tipc_node_pre_cleanup_net(struct net *exit_net);
 #endif
-- 
2.13.7

Re: [net-next v2 0/5] TIPC Encryption

[David Miller]

From: Tuong Lien <tuong.t.lien@dektech.com.au>
Date: Fri,  8 Nov 2019 12:05:07 +0700

> This series provides TIPC encryption feature, kernel part. There will be
> another one in the 'iproute2/tipc' for user space to set key.
> 
> v2: add select crypto 'aes(gcm)' for TIPC_CRYPTO in Kconfig

Series applied, thanks.