diff mbox series

[v7,08/22] net/tcp: Add AO sign to RST packets

Message ID 20230614230947.3954084-9-dima@arista.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net/tcp: Add TCP-AO support | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply, async

Commit Message

Dmitry Safonov June 14, 2023, 11:09 p.m. UTC 
Wire up sending resets to TCP-AO hashing.

Co-developed-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Co-developed-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 include/net/tcp_ao.h |  12 +++++
 net/ipv4/tcp_ao.c    | 102 ++++++++++++++++++++++++++++++++++++++++++-
 net/ipv4/tcp_ipv4.c  |  76 ++++++++++++++++++++++++--------
 net/ipv6/tcp_ipv6.c  |  67 ++++++++++++++++++++++------
 4 files changed, 223 insertions(+), 34 deletions(-)

Comments

kernel test robot June 15, 2023, 1:22 a.m. UTC | #1 
Hi Dmitry,

kernel test robot noticed the following build warnings:

[auto build test WARNING on b6dad5178ceaf23f369c3711062ce1f2afc33644]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Safonov/net-tcp-Prepare-tcp_md5sig_pool-for-TCP-AO/20230615-071334
base:   b6dad5178ceaf23f369c3711062ce1f2afc33644
patch link:    https://lore.kernel.org/r/20230614230947.3954084-9-dima%40arista.com
patch subject: [PATCH v7 08/22] net/tcp: Add AO sign to RST packets
config: i386-randconfig-r021-20230612 (https://download.01.org/0day-ci/archive/20230615/202306150911.gIaFpxg9-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build):
        git checkout b6dad5178ceaf23f369c3711062ce1f2afc33644
        b4 shazam https://lore.kernel.org/r/20230614230947.3954084-9-dima@arista.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash net/ipv6/

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306150911.gIaFpxg9-lkp@intel.com/

All warnings (new ones prefixed by >>):

   net/ipv6/tcp_ipv6.c: In function 'tcp_v6_send_reset':
>> net/ipv6/tcp_ipv6.c:1136:1: warning: label 'out' defined but not used [-Wunused-label]
    1136 | out:
         | ^~~


vim +/out +1136 net/ipv6/tcp_ipv6.c

2045a93527d963 Dmitry Safonov           2023-06-15  1110  
c24b14c46bb88d Song Liu                 2017-10-23  1111  	if (sk) {
c24b14c46bb88d Song Liu                 2017-10-23  1112  		oif = sk->sk_bound_dev_if;
052e0690f1f62f Eric Dumazet             2019-07-10  1113  		if (sk_fullsock(sk)) {
052e0690f1f62f Eric Dumazet             2019-07-10  1114  			const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
052e0690f1f62f Eric Dumazet             2019-07-10  1115  
c24b14c46bb88d Song Liu                 2017-10-23  1116  			trace_tcp_send_reset(sk, skb);
052e0690f1f62f Eric Dumazet             2019-07-10  1117  			if (np->repflow)
052e0690f1f62f Eric Dumazet             2019-07-10  1118  				label = ip6_flowlabel(ipv6h);
e9a5dceee56cb5 Eric Dumazet             2019-09-24  1119  			priority = sk->sk_priority;
dc6456e938e938 Antoine Tenart           2023-04-27  1120  			txhash = sk->sk_txhash;
052e0690f1f62f Eric Dumazet             2019-07-10  1121  		}
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1122  		if (sk->sk_state == TCP_TIME_WAIT) {
50a8accf10627b Eric Dumazet             2019-06-05  1123  			label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1124  			priority = inet_twsk(sk)->tw_priority;
9258b8b1be2e1e Eric Dumazet             2022-09-22  1125  			txhash = inet_twsk(sk)->tw_txhash;
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1126  		}
323a53c41292a0 Eric Dumazet             2019-06-05  1127  	} else {
a346abe051bd2b Eric Dumazet             2019-07-01  1128  		if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
323a53c41292a0 Eric Dumazet             2019-06-05  1129  			label = ip6_flowlabel(ipv6h);
c24b14c46bb88d Song Liu                 2017-10-23  1130  	}
c24b14c46bb88d Song Liu                 2017-10-23  1131  
e92dd77e6fe0a3 Wei Wang                 2020-09-08  1132  	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
2045a93527d963 Dmitry Safonov           2023-06-15  1133  			     ipv6_get_dsfield(ipv6h), label, priority, txhash,
2045a93527d963 Dmitry Safonov           2023-06-15  1134  			     ao_key, traffic_key, rcv_next, ao_sne);
658ddaaf6694ad Shawn Lu                 2012-01-31  1135  
3b24d854cb3538 Eric Dumazet             2016-04-01 @1136  out:
658ddaaf6694ad Shawn Lu                 2012-01-31  1137  	rcu_read_unlock();
ecc51b6d5ca04b Arnaldo Carvalho de Melo 2005-12-12  1138  }
^1da177e4c3f41 Linus Torvalds           2005-04-16  1139
kernel test robot June 15, 2023, 1:23 a.m. UTC | #2 
Hi Dmitry,

kernel test robot noticed the following build warnings:

[auto build test WARNING on b6dad5178ceaf23f369c3711062ce1f2afc33644]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Safonov/net-tcp-Prepare-tcp_md5sig_pool-for-TCP-AO/20230615-071334
base:   b6dad5178ceaf23f369c3711062ce1f2afc33644
patch link:    https://lore.kernel.org/r/20230614230947.3954084-9-dima%40arista.com
patch subject: [PATCH v7 08/22] net/tcp: Add AO sign to RST packets
config: hexagon-randconfig-r025-20230612 (https://download.01.org/0day-ci/archive/20230615/202306150955.0sJRXmfG-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout b6dad5178ceaf23f369c3711062ce1f2afc33644
        b4 shazam https://lore.kernel.org/r/20230614230947.3954084-9-dima@arista.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash net/ipv6/

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306150955.0sJRXmfG-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from net/ipv6/tcp_ipv6.c:32:
   In file included from include/linux/netdevice.h:38:
   In file included from include/net/net_namespace.h:43:
   In file included from include/linux/skbuff.h:17:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:334:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     547 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     560 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   In file included from net/ipv6/tcp_ipv6.c:32:
   In file included from include/linux/netdevice.h:38:
   In file included from include/net/net_namespace.h:43:
   In file included from include/linux/skbuff.h:17:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:334:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     573 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
         |                                                   ^
   In file included from net/ipv6/tcp_ipv6.c:32:
   In file included from include/linux/netdevice.h:38:
   In file included from include/net/net_namespace.h:43:
   In file included from include/linux/skbuff.h:17:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:334:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     584 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     594 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     604 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
>> net/ipv6/tcp_ipv6.c:1136:1: warning: unused label 'out' [-Wunused-label]
    1136 | out:
         | ^~~~
    1137 |         rcu_read_unlock();
   7 warnings generated.


vim +/out +1136 net/ipv6/tcp_ipv6.c

2045a93527d963 Dmitry Safonov           2023-06-15  1110  
c24b14c46bb88d Song Liu                 2017-10-23  1111  	if (sk) {
c24b14c46bb88d Song Liu                 2017-10-23  1112  		oif = sk->sk_bound_dev_if;
052e0690f1f62f Eric Dumazet             2019-07-10  1113  		if (sk_fullsock(sk)) {
052e0690f1f62f Eric Dumazet             2019-07-10  1114  			const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
052e0690f1f62f Eric Dumazet             2019-07-10  1115  
c24b14c46bb88d Song Liu                 2017-10-23  1116  			trace_tcp_send_reset(sk, skb);
052e0690f1f62f Eric Dumazet             2019-07-10  1117  			if (np->repflow)
052e0690f1f62f Eric Dumazet             2019-07-10  1118  				label = ip6_flowlabel(ipv6h);
e9a5dceee56cb5 Eric Dumazet             2019-09-24  1119  			priority = sk->sk_priority;
dc6456e938e938 Antoine Tenart           2023-04-27  1120  			txhash = sk->sk_txhash;
052e0690f1f62f Eric Dumazet             2019-07-10  1121  		}
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1122  		if (sk->sk_state == TCP_TIME_WAIT) {
50a8accf10627b Eric Dumazet             2019-06-05  1123  			label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1124  			priority = inet_twsk(sk)->tw_priority;
9258b8b1be2e1e Eric Dumazet             2022-09-22  1125  			txhash = inet_twsk(sk)->tw_txhash;
f6c0f5d209fa80 Eric Dumazet             2019-09-24  1126  		}
323a53c41292a0 Eric Dumazet             2019-06-05  1127  	} else {
a346abe051bd2b Eric Dumazet             2019-07-01  1128  		if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
323a53c41292a0 Eric Dumazet             2019-06-05  1129  			label = ip6_flowlabel(ipv6h);
c24b14c46bb88d Song Liu                 2017-10-23  1130  	}
c24b14c46bb88d Song Liu                 2017-10-23  1131  
e92dd77e6fe0a3 Wei Wang                 2020-09-08  1132  	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
2045a93527d963 Dmitry Safonov           2023-06-15  1133  			     ipv6_get_dsfield(ipv6h), label, priority, txhash,
2045a93527d963 Dmitry Safonov           2023-06-15  1134  			     ao_key, traffic_key, rcv_next, ao_sne);
658ddaaf6694ad Shawn Lu                 2012-01-31  1135  
3b24d854cb3538 Eric Dumazet             2016-04-01 @1136  out:
658ddaaf6694ad Shawn Lu                 2012-01-31  1137  	rcu_read_unlock();
ecc51b6d5ca04b Arnaldo Carvalho de Melo 2005-12-12  1138  }
^1da177e4c3f41 Linus Torvalds           2005-04-16  1139
kernel test robot June 15, 2023, 11:47 a.m. UTC | #3 
Hi Dmitry,

kernel test robot noticed the following build errors:

[auto build test ERROR on b6dad5178ceaf23f369c3711062ce1f2afc33644]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Safonov/net-tcp-Prepare-tcp_md5sig_pool-for-TCP-AO/20230615-071334
base:   b6dad5178ceaf23f369c3711062ce1f2afc33644
patch link:    https://lore.kernel.org/r/20230614230947.3954084-9-dima%40arista.com
patch subject: [PATCH v7 08/22] net/tcp: Add AO sign to RST packets
config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20230615/202306151905.1KMdlW2R-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout b6dad5178ceaf23f369c3711062ce1f2afc33644
        b4 shazam https://lore.kernel.org/r/20230614230947.3954084-9-dima@arista.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306151905.1KMdlW2R-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "tcp_ao_prepare_reset" [net/ipv6/ipv6.ko] undefined!
ERROR: modpost: "tcp_v6_ao_calc_key_sk" [net/ipv6/ipv6.ko] undefined!
diff mbox series

Patch

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 72fc87cf58bf..010c77c4456e 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -121,6 +121,8 @@  int tcp_ao_hash_skb(unsigned short int family,
 		    const u8 *tkey, int hash_offset, u32 sne);
 int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
 		 sockptr_t optval, int optlen);
+struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+					  int sndid, int rcvid);
 int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
 			    unsigned int len);
 void tcp_ao_destroy_sock(struct sock *sk);
@@ -128,6 +130,16 @@  u32 tcp_ao_compute_sne(u32 sne, u32 seq, u32 new_seq);
 struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
 				    const union tcp_ao_addr *addr,
 				    int family, int sndid, int rcvid, u16 port);
+int tcp_ao_hash_hdr(unsigned short family, char *ao_hash,
+		struct tcp_ao_key *key, const u8 *tkey,
+		const union tcp_ao_addr *daddr,
+		const union tcp_ao_addr *saddr,
+		const struct tcphdr *th, u32 sne);
+int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
+			 const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
+			 struct tcp_ao_key **key, char **traffic_key,
+			 u8 *keyid, u32 *sne);
+
 /* ipv4 specific functions */
 int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
 struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 3889628bdcc1..a45ab30265bf 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -56,8 +56,8 @@  int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
  * it's known that the keys in ao_info are matching peer's
  * family/address/port/VRF/etc.
  */
-static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
-						 int sndid, int rcvid)
+struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+					  int sndid, int rcvid)
 {
 	struct tcp_ao_key *key;
 
@@ -70,6 +70,7 @@  static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(tcp_ao_established_key);
 
 static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
 				  const struct in_addr *addr2,
@@ -387,6 +388,61 @@  static int tcp_ao_hash_header(struct tcp_sigpool *hp,
 	return err;
 }
 
+int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash,
+		    struct tcp_ao_key *key, const u8 *tkey,
+		    const union tcp_ao_addr *daddr,
+		    const union tcp_ao_addr *saddr,
+		    const struct tcphdr *th, u32 sne)
+{
+	__u8 tmp_hash[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align;
+	int tkey_len = tcp_ao_digest_size(key);
+	int hash_offset = ao_hash - (char *)th;
+	struct tcp_sigpool hp;
+
+	if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
+		goto clear_hash_noput;
+
+	if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
+		goto clear_hash;
+
+	if (crypto_ahash_init(hp.req))
+		goto clear_hash;
+
+	if (tcp_ao_hash_sne(&hp, sne))
+		goto clear_hash;
+	if (family == AF_INET) {
+		if (tcp_v4_ao_hash_pseudoheader(&hp, daddr->a4.s_addr,
+						saddr->a4.s_addr, th->doff * 4))
+			goto clear_hash;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		if (tcp_v6_ao_hash_pseudoheader(&hp, &daddr->a6,
+						&saddr->a6, th->doff * 4))
+			goto clear_hash;
+#endif
+	} else {
+		WARN_ON_ONCE(1);
+		goto clear_hash;
+	}
+	if (tcp_ao_hash_header(&hp, th, false,
+			       ao_hash, hash_offset, tcp_ao_maclen(key)))
+		goto clear_hash;
+	ahash_request_set_crypt(hp.req, NULL, tmp_hash, 0);
+	if (crypto_ahash_final(hp.req))
+		goto clear_hash;
+
+	memcpy(ao_hash, tmp_hash, tcp_ao_maclen(key));
+	tcp_sigpool_end(&hp);
+	return 0;
+
+clear_hash:
+	tcp_sigpool_end(&hp);
+clear_hash_noput:
+	memset(ao_hash, 0, tcp_ao_maclen(key));
+	return 1;
+}
+EXPORT_SYMBOL_GPL(tcp_ao_hash_hdr);
+
 int tcp_ao_hash_skb(unsigned short int family,
 		    char *ao_hash, struct tcp_ao_key *key,
 		    const struct sock *sk, const struct sk_buff *skb,
@@ -449,6 +505,48 @@  struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
 	return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
 }
 
+int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
+			 const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
+			 struct tcp_ao_key **key, char **traffic_key,
+			 u8 *keyid, u32 *sne)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	struct tcp_ao_info *ao_info;
+
+	/* If there's no socket - than initial sisn/disn are unknown.
+	 * Drop the segment. RFC5925 (7.7) advises to require graceful
+	 * restart [RFC4724]. Alternatively, the RFC5925 advises to
+	 * save/restore traffic keys before/after reboot.
+	 * Linux TCP-AO support provides TCP_AO_ADD_KEY and TCP_REPAIR
+	 * options to restore a socket post-reboot.
+	 */
+	if (!sk)
+		return -ENOTCONN;
+
+	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
+		return -1;
+	} else {
+		struct tcp_ao_key *rnext_key;
+
+		if (sk->sk_state == TCP_TIME_WAIT)
+			return -1;
+		ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+		if (!ao_info)
+			return -ENOENT;
+
+		*key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+		if (!*key)
+			return -ENOENT;
+		*traffic_key = snd_other_key(*key);
+		rnext_key = READ_ONCE(ao_info->rnext_key);
+		*keyid = rnext_key->rcvid;
+		*sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
+					  READ_ONCE(ao_info->snd_sne_seq),
+					  ntohl(seq));
+	}
+	return 0;
+}
+
 static int tcp_ao_cache_traffic_keys(const struct sock *sk,
 				     struct tcp_ao_info *ao,
 				     struct tcp_ao_key *ao_key)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 05fa0aab0b8d..9638bab8ed92 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -655,6 +655,49 @@  void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(tcp_v4_send_check);
 
+#define REPLY_OPTIONS_LEN      (MAX_TCP_OPTION_SPACE / sizeof(__be32))
+
+static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb,
+				 const struct tcp_ao_hdr *aoh,
+				 struct ip_reply_arg *arg, struct tcphdr *reply,
+				 __be32 reply_options[REPLY_OPTIONS_LEN])
+{
+#ifdef CONFIG_TCP_AO
+	char key_buf[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align;
+	char *traffic_key = key_buf;
+	int sdif = tcp_v4_sdif(skb);
+	int dif = inet_iif(skb);
+	int l3index = sdif ? dif : 0;
+	struct tcp_ao_key *key;
+	bool drop = true;
+	u32 ao_sne = 0;
+	u8 keyid;
+
+	rcu_read_lock();
+	if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, reply->seq,
+				 &key, &traffic_key, &keyid, &ao_sne))
+		goto out;
+
+	reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) |
+				 (aoh->rnext_keyid << 8) | keyid);
+	arg->iov[0].iov_len += round_up(tcp_ao_len(key), 4);
+	reply->doff = arg->iov[0].iov_len / 4;
+
+	if (tcp_ao_hash_hdr(AF_INET, (char *)&reply_options[1],
+			    key, traffic_key,
+			    (union tcp_ao_addr *)&ip_hdr(skb)->saddr,
+			    (union tcp_ao_addr *)&ip_hdr(skb)->daddr,
+			    reply, ao_sne))
+		goto out;
+	drop = false;
+out:
+	rcu_read_unlock();
+	return drop;
+#else
+	return true;
+#endif
+}
+
 /*
  *	This routine will send an RST to the other tcp.
  *
@@ -668,32 +711,25 @@  EXPORT_SYMBOL(tcp_v4_send_check);
  *	Exception: precedence violation. We do not implement it in any case.
  */
 
-#ifdef CONFIG_TCP_AO
-#define OPTION_BYTES MAX_TCP_OPTION_SPACE
-#elif defined(CONFIG_TCP_MD5SIG)
-#define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED
-#else
-#define OPTION_BYTES sizeof(__be32)
-#endif
-
 static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct {
 		struct tcphdr th;
-		__be32 opt[OPTION_BYTES / sizeof(__be32)];
+		__be32 opt[REPLY_OPTIONS_LEN];
 	} rep;
 	struct ip_reply_arg arg;
-#ifdef CONFIG_TCP_MD5SIG
-	struct tcp_md5sig_key *key = NULL;
-	const __u8 *md5_hash_location = NULL;
-	unsigned char newhash[16];
-	int genhash;
-	struct sock *sk1 = NULL;
-#endif
 	u64 transmit_time = 0;
 	struct sock *ctl_sk;
 	struct net *net;
+	const __u8 *md5_hash_location = NULL;
+	const struct tcp_ao_hdr *aoh;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *key = NULL;
+	unsigned char newhash[16];
+	struct sock *sk1 = NULL;
+	int genhash;
+#endif
 
 	/* Never send a reset in response to a reset. */
 	if (th->rst)
@@ -725,11 +761,15 @@  static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	arg.iov[0].iov_len  = sizeof(rep.th);
 
 	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
-#ifdef CONFIG_TCP_MD5SIG
+
 	/* Invalid TCP option size or twice included auth */
-	if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, NULL))
+	if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, &aoh))
 		return;
 
+	if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, &arg, &rep.th, rep.opt))
+		return;
+
+#ifdef CONFIG_TCP_MD5SIG
 	rcu_read_lock();
 	if (sk && sk_fullsock(sk)) {
 		const union tcp_md5_addr *addr;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0074d1f1f8a5..282603cb009c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -858,7 +858,9 @@  const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 				 u32 ack, u32 win, u32 tsval, u32 tsecr,
 				 int oif, struct tcp_md5sig_key *key, int rst,
-				 u8 tclass, __be32 label, u32 priority, u32 txhash)
+				 u8 tclass, __be32 label, u32 priority, u32 txhash,
+				 struct tcp_ao_key *ao_key, char *tkey,
+				 u8 rcv_next, u32 ao_sne)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct tcphdr *t1;
@@ -877,6 +879,13 @@  static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
 	if (key)
 		tot_len += TCPOLEN_MD5SIG_ALIGNED;
 #endif
+#ifdef CONFIG_TCP_AO
+	if (ao_key)
+		tot_len += tcp_ao_len(ao_key);
+#endif
+#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO)
+	WARN_ON_ONCE(key && ao_key);
+#endif
 
 #ifdef CONFIG_MPTCP
 	if (rst && !key) {
@@ -928,6 +937,17 @@  static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
 				    &ipv6_hdr(skb)->daddr, t1);
 	}
 #endif
+#ifdef CONFIG_TCP_AO
+	if (ao_key) {
+		*topt++ = htonl((TCPOPT_AO << 24) | (tcp_ao_len(ao_key) << 16) |
+				(ao_key->sndid << 8) | (rcv_next));
+
+		tcp_ao_hash_hdr(AF_INET6, (char *)topt, ao_key, tkey,
+				(union tcp_ao_addr *)&ipv6_hdr(skb)->saddr,
+				(union tcp_ao_addr *)&ipv6_hdr(skb)->daddr,
+				t1, ao_sne);
+	}
+#endif
 
 	memset(&fl6, 0, sizeof(fl6));
 	fl6.daddr = ipv6_hdr(skb)->saddr;
@@ -992,17 +1012,27 @@  static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 	u32 seq = 0, ack_seq = 0;
 	struct tcp_md5sig_key *key = NULL;
-#ifdef CONFIG_TCP_MD5SIG
+	__be32 label = 0;
+	u32 priority = 0;
+	struct net *net;
+	struct tcp_ao_key *ao_key = NULL;
+	u8 rcv_next = 0;
+	u32 ao_sne = 0;
+	u32 txhash = 0;
+	int oif = 0;
 	const __u8 *md5_hash_location = NULL;
+	const struct tcp_ao_hdr *aoh;
+#ifdef CONFIG_TCP_MD5SIG
 	unsigned char newhash[16];
 	int genhash;
 	struct sock *sk1 = NULL;
 #endif
-	__be32 label = 0;
-	u32 priority = 0;
-	struct net *net;
-	u32 txhash = 0;
-	int oif = 0;
+#ifdef CONFIG_TCP_AO
+	char key_buf[TCP_AO_MAX_HASH_SIZE] __tcp_ao_key_align;
+	char *traffic_key = key_buf;
+#else
+	u8 *traffic_key = NULL;
+#endif
 
 	if (th->rst)
 		return;
@@ -1014,12 +1044,11 @@  static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 		return;
 
 	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
-#ifdef CONFIG_TCP_MD5SIG
 	/* Invalid TCP option size or twice included auth */
-	if (tcp_parse_auth_options(th, &md5_hash_location, NULL))
+	if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
 		return;
-
 	rcu_read_lock();
+#ifdef CONFIG_TCP_MD5SIG
 	if (sk && sk_fullsock(sk)) {
 		int l3index;
 
@@ -1068,6 +1097,17 @@  static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 			  (th->doff << 2);
 
+#ifdef CONFIG_TCP_AO
+	if (aoh) {
+		int l3index;
+
+		l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+		if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq, &ao_key,
+					 &traffic_key, &rcv_next, &ao_sne))
+			goto out;
+	}
+#endif
+
 	if (sk) {
 		oif = sk->sk_bound_dev_if;
 		if (sk_fullsock(sk)) {
@@ -1090,12 +1130,11 @@  static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 	}
 
 	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
-			     ipv6_get_dsfield(ipv6h), label, priority, txhash);
+			     ipv6_get_dsfield(ipv6h), label, priority, txhash,
+			     ao_key, traffic_key, rcv_next, ao_sne);
 
-#ifdef CONFIG_TCP_MD5SIG
 out:
 	rcu_read_unlock();
-#endif
 }
 
 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
@@ -1104,7 +1143,7 @@  static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 			    __be32 label, u32 priority, u32 txhash)
 {
 	tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
-			     tclass, label, priority, txhash);
+			     tclass, label, priority, txhash, NULL, NULL, 0, 0);
 }
 
 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)