tipc: introduce TIPC encryption & authentication

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

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"

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

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)

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))))
+	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
+	} 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;
@@ -541,11 +548,16 @@ 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))))
+		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
+		} 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;

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);

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)

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)

net/tipc/crypto.h

+/* 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

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);

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,

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;
 }
 

net/tipc/msg.h

@@ -102,6 +102,8 @@ struct plist;
 #define TIPC_MEDIA_INFO_OFFSET	5
 
 struct tipc_skb_cb {
+	union {
+		struct {
 			struct sk_buff *tail;
 			unsigned long nxt_retr;
 			unsigned long retr_stamp;
@@ -110,8 +112,32 @@ struct tipc_skb_cb {
 			u16 chain_imp;
 			u16 ackers;
 			u16 retr_cnt;
-	bool validated;
-};
+		} __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]))
 

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;
 }
 

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,

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
 	{}
 };
 

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;
 	}