diff mbox series

[v2,23/35] net/tcp: Add getsockopt(TCP_AO_GET)

Message ID 20220923201319.493208-24-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 Sept. 23, 2022, 8:13 p.m. UTC
Introduce getsockopt() that let user get TCP-AO keys and their
properties from a socket. A user can provide a filter to match
a specific key to be dumped or TCP_AO_GET_ALL flag may be used to dump
all keys in one syscall.

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     |   1 +
 include/uapi/linux/tcp.h |  19 ++++
 net/ipv4/tcp.c           |  11 ++
 net/ipv4/tcp_ao.c        | 223 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 254 insertions(+)

Comments

kernel test robot Sept. 24, 2022, 6:44 a.m. UTC | #1
Hi Dmitry,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on bf682942cd26ce9cd5e87f73ae099b383041e782]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Safonov/net-tcp-Add-TCP-AO-support/20220924-042311
base:   bf682942cd26ce9cd5e87f73ae099b383041e782
config: um-x86_64_defconfig
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/464de48068a05d5b8690ca346f382b74914e5ce3
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Dmitry-Safonov/net-tcp-Add-TCP-AO-support/20220924-042311
        git checkout 464de48068a05d5b8690ca346f382b74914e5ce3
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um SUBARCH=x86_64 SHELL=/bin/bash net/ipv4/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   net/ipv4/tcp_ao.c:113:20: warning: no previous prototype for 'tcp_ao_do_lookup_keyid' [-Wmissing-prototypes]
     113 | struct tcp_ao_key *tcp_ao_do_lookup_keyid(struct tcp_ao_info *ao,
         |                    ^~~~~~~~~~~~~~~~~~~~~~
   net/ipv4/tcp_ao.c:270:20: warning: no previous prototype for 'tcp_ao_copy_key' [-Wmissing-prototypes]
     270 | struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk, struct tcp_ao_key *key)
         |                    ^~~~~~~~~~~~~~~
>> net/ipv4/tcp_ao.c:1778:5: warning: no previous prototype for 'tcp_ao_copy_mkts_to_user' [-Wmissing-prototypes]
    1778 | int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
         |     ^~~~~~~~~~~~~~~~~~~~~~~~


vim +/tcp_ao_copy_mkts_to_user +1778 net/ipv4/tcp_ao.c

  1742	
  1743	/* tcp_ao_copy_mkts_to_user(ao_info, optval, optlen)
  1744	 *
  1745	 * @ao_info:	struct tcp_ao_info on the socket that
  1746	 *		socket getsockopt(TCP_AO_GET) is executed on
  1747	 * @optval:	pointer to array of tcp_ao_getsockopt structures in user space.
  1748	 *		Must be != NULL.
  1749	 * @optlen:	pointer to size of tcp_ao_getsockopt structure.
  1750	 *		Must be != NULL.
  1751	 *
  1752	 * Return value: 0 on success, a negative error number otherwise.
  1753	 *
  1754	 * optval points to an array of tcp_ao_getsockopt structures in user space.
  1755	 * optval[0] is used as both input and output to getsockopt. It determines
  1756	 * which keys are returned by the kernel.
  1757	 * optval[0].nkeys is the size of the array in user space. On return it contains
  1758	 * the number of keys matching the search criteria.
  1759	 * If TCP_AO_GET_ALL is set in "flags", then all keys in the socket are
  1760	 * returned, otherwise only keys matching <addr, prefix, sndid, rcvid>
  1761	 * in optval[0] are returned.
  1762	 * optlen is also used as both input and output. The user provides the size
  1763	 * of struct tcp_ao_getsockopt in user space, and the kernel returns the size
  1764	 * of the structure in kernel space.
  1765	 * The size of struct tcp_ao_getsockopt may differ between user and kernel.
  1766	 * There are three cases to consider:
  1767	 *  * If usize == ksize, then keys are copied verbatim.
  1768	 *  * If usize < ksize, then the userspace has passed an old struct to a
  1769	 *    newer kernel. The rest of the trailing bytes in optval[0]
  1770	 *    (ksize - usize) are interpreted as 0 by the kernel.
  1771	 *  * If usize > ksize, then the userspace has passed a new struct to an
  1772	 *    older kernel. The trailing bytes unknown to the kernel (usize - ksize)
  1773	 *    are checked to ensure they are zeroed, otherwise -E2BIG is returned.
  1774	 * On return the kernel fills in min(usize, ksize) in each entry of the array.
  1775	 * The layout of the fields in the user and kernel structures is expected to
  1776	 * be the same (including in the 32bit vs 64bit case).
  1777	 */
> 1778	int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
  1779				     char __user *optval, int __user *optlen)
  1780	{
  1781		struct tcp_ao_getsockopt opt_in;
  1782		struct tcp_ao_getsockopt opt_out;
  1783		struct tcp_ao_getsockopt __user *optval_in;
  1784		int user_len;
  1785		unsigned int max_keys;	/* maximum number of keys to copy to user */
  1786		u32 copied_keys;	/* keys copied to user so far */
  1787		int matched_keys;	/* keys from ao_info matched so far */
  1788		int bytes_to_write;	/* number of bytes to write to user level */
  1789		struct tcp_ao_key *key;
  1790		struct sockaddr_in *sin;   /* (struct sockaddr_in *)&opt_in.addr */
  1791		struct sockaddr_in6 *sin6; /* (struct sockaddr_in6 *)&opt_in.addr */
  1792		struct in6_addr *addr6;    /* &sin6->sin6_addr */
  1793		__kernel_sa_family_t ss_family;
  1794		union tcp_ao_addr *addr;
  1795		int optlen_out;
  1796		u8 prefix_in;
  1797		u16 port = 0;
  1798		bool copy_all, copy_current, copy_next;
  1799		int err;
  1800	
  1801		if (get_user(user_len, optlen))
  1802			return -EFAULT;
  1803	
  1804		if (user_len <= 0)
  1805			return -EINVAL;
  1806	
  1807		memset(&opt_in, 0, sizeof(struct tcp_ao_getsockopt));
  1808		err = copy_struct_from_user(&opt_in, sizeof(struct tcp_ao_getsockopt),
  1809					    optval, user_len);
  1810		if (err < 0)
  1811			return err;
  1812	
  1813		optval_in = (struct tcp_ao_getsockopt __user *)optval;
  1814		ss_family = opt_in.addr.ss_family;
  1815	
  1816		BUILD_BUG_ON(TCP_AO_GET_ALL & (TCP_AO_GET_CURR | TCP_AO_GET_NEXT));
  1817		if (opt_in.flags & ~TCP_AO_GETF_VALID)
  1818			return -EINVAL;
  1819	
  1820		max_keys = opt_in.nkeys;
  1821		copy_all = !!(opt_in.flags & TCP_AO_GET_ALL);
  1822		copy_current = !!(opt_in.flags & TCP_AO_GET_CURR);
  1823		copy_next = !!(opt_in.flags & TCP_AO_GET_NEXT);
  1824	
  1825		if (!(copy_all || copy_current || copy_next)) {
  1826			prefix_in = opt_in.prefix;
  1827	
  1828			switch (ss_family) {
  1829			case AF_INET: {
  1830				sin = (struct sockaddr_in *)&opt_in.addr;
  1831				port = sin->sin_port;
  1832				addr = (union tcp_ao_addr *)&sin->sin_addr;
  1833	
  1834				if (prefix_in > 32)
  1835					return -EINVAL;
  1836	
  1837				if (sin->sin_addr.s_addr == INADDR_ANY &&
  1838				    prefix_in != 0)
  1839					return -EINVAL;
  1840	
  1841				break;
  1842			}
  1843			case AF_INET6: {
  1844				sin6 = (struct sockaddr_in6 *)&opt_in.addr;
  1845				addr = (union tcp_ao_addr *)&sin6->sin6_addr;
  1846				addr6 = &sin6->sin6_addr;
  1847				port = sin6->sin6_port;
  1848	
  1849				if (prefix_in != 0) {
  1850					if (ipv6_addr_v4mapped(addr6)) {
  1851						__be32 addr4 = addr6->s6_addr32[3];
  1852	
  1853						if (prefix_in > 32 ||
  1854						    addr4 == INADDR_ANY)
  1855							return -EINVAL;
  1856					} else {
  1857						if (ipv6_addr_any(addr6) ||
  1858						    prefix_in > 128)
  1859							return -EINVAL;
  1860					}
  1861				} else if (!ipv6_addr_any(addr6)) {
  1862					return -EINVAL;
  1863				}
  1864	
  1865				break;
  1866			}
  1867			default:
  1868				return -EINVAL;
  1869			}
  1870		}
  1871	
  1872		bytes_to_write = min(user_len, (int)sizeof(struct tcp_ao_getsockopt));
  1873		copied_keys = 0;
  1874		matched_keys = 0;
  1875	
  1876		hlist_for_each_entry_rcu(key, &ao_info->head, node) {
  1877			if (copy_all)
  1878				goto match;
  1879	
  1880			if (copy_current || copy_next) {
  1881				if (copy_current && key == ao_info->current_key)
  1882					goto match;
  1883				if (copy_next && key == ao_info->rnext_key)
  1884					goto match;
  1885				continue;
  1886			}
  1887	
  1888			if (tcp_ao_key_cmp(key, addr, opt_in.prefix,
  1889					   opt_in.addr.ss_family,
  1890					   opt_in.sndid, opt_in.rcvid, port) != 0)
  1891				continue;
  1892	match:
  1893			matched_keys++;
  1894			if (copied_keys >= max_keys)
  1895				continue;
  1896	
  1897			memset(&opt_out, 0, sizeof(struct tcp_ao_getsockopt));
  1898	
  1899			if (key->family == AF_INET) {
  1900				struct sockaddr_in *sin_out = (struct sockaddr_in *)&opt_out.addr;
  1901	
  1902				sin_out->sin_family = key->family;
  1903				sin_out->sin_port = ntohs(key->port);
  1904				memcpy(&sin_out->sin_addr, &key->addr, sizeof(struct in_addr));
  1905			} else {
  1906				struct sockaddr_in6 *sin6_out = (struct sockaddr_in6 *)&opt_out.addr;
  1907	
  1908				sin6_out->sin6_family = key->family;
  1909				sin6_out->sin6_port = ntohs(key->port);
  1910				memcpy(&sin6_out->sin6_addr, &key->addr, sizeof(struct in6_addr));
  1911			}
  1912			opt_out.sndid = key->sndid;
  1913			opt_out.rcvid = key->rcvid;
  1914			opt_out.prefix = key->prefixlen;
  1915			opt_out.keyflags = key->keyflags;
  1916			opt_out.flags = 0;
  1917			if (key == ao_info->current_key)
  1918				opt_out.flags |= TCP_AO_GET_CURR;
  1919			if (key == ao_info->rnext_key)
  1920				opt_out.flags |= TCP_AO_GET_NEXT;
  1921			opt_out.nkeys = 0;
  1922			opt_out.maclen = key->maclen;
  1923			opt_out.keylen = key->keylen;
  1924			memcpy(&opt_out.key, key->key, key->keylen);
  1925			crypto_pool_algo(key->crypto_pool_id, opt_out.alg_name, 64);
  1926	
  1927			/* Copy key to user */
  1928			if (copy_to_user(optval, &opt_out, bytes_to_write))
  1929				return -EFAULT;
  1930			optval += user_len;
  1931			copied_keys++;
  1932		}
  1933	
  1934		optlen_out = (int)sizeof(struct tcp_ao_getsockopt);
  1935		if (copy_to_user(optlen, &optlen_out, sizeof(int)))
  1936			return -EFAULT;
  1937	
  1938		if (copy_to_user(&optval_in->nkeys, &matched_keys, sizeof(u32)))
  1939			return -EFAULT;
  1940	
  1941		return 0;
  1942	}
  1943
diff mbox series

Patch

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 743a910ba508..b5088d4c5587 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -174,6 +174,7 @@  void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
 int tcp_ao_cache_traffic_keys(const struct sock *sk, struct tcp_ao_info *ao,
 			      struct tcp_ao_key *ao_key);
 bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code);
+int tcp_ao_get_mkts(struct sock *sk, char __user *optval, int __user *optlen);
 enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
 			const struct sk_buff *skb, unsigned short int family,
 			const struct request_sock *req,
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index b60933ee2a27..453187d21da8 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -132,6 +132,7 @@  enum {
 #define TCP_AO			38	/* (Add/Set MKT) */
 #define TCP_AO_DEL		39	/* (Delete MKT) */
 #define TCP_AO_MOD		40	/* (Modify MKT) */
+#define TCP_AO_GET		41	/* (Get MKTs) */
 
 #define TCP_REPAIR_ON		1
 #define TCP_REPAIR_OFF		0
@@ -353,6 +354,10 @@  struct tcp_diag_md5sig {
 #define TCP_AO_CMDF_NEXT	(1 << 1)	/* Only checks field rcvid */
 #define TCP_AO_CMDF_ACCEPT_ICMP	(1 << 2)	/* Accept incoming ICMPs */
 
+#define TCP_AO_GET_CURR		TCP_AO_CMDF_CURR
+#define TCP_AO_GET_NEXT		TCP_AO_CMDF_NEXT
+#define TCP_AO_GET_ALL		(1 << 2)
+
 struct tcp_ao { /* setsockopt(TCP_AO) */
 	struct __kernel_sockaddr_storage tcpa_addr;
 	char	tcpa_alg_name[64];
@@ -382,6 +387,20 @@  struct tcp_ao_mod { /* setsockopt(TCP_AO_MOD) */
 	__u8	tcpa_rnext;
 } __attribute__((aligned(8)));
 
+struct tcp_ao_getsockopt { /* getsockopt(TCP_AO_GET) */
+	struct __kernel_sockaddr_storage addr;
+	__u8	sndid;
+	__u8	rcvid;
+	__u32	nkeys;
+	char	alg_name[64];
+	__u16	flags;
+	__u8	prefix;
+	__u8	maclen;
+	__u8	keyflags;
+	__u8	keylen;
+	__u8	key[TCP_AO_MAXKEYLEN];
+} __attribute__((aligned(8)));
+
 /* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
 
 #define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f7ad4443c350..edc27b0d7cb2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4382,6 +4382,17 @@  static int do_tcp_getsockopt(struct sock *sk, int level,
 			err = -EFAULT;
 		return err;
 	}
+#endif
+#ifdef CONFIG_TCP_AO
+	case TCP_AO_GET: {
+		int err;
+
+		lock_sock(sk);
+		err = tcp_ao_get_mkts(sk, optval, optlen);
+		release_sock(sk);
+
+		return err;
+	}
 #endif
 	default:
 		return -ENOPROTOOPT;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index f5489b73fae0..8f569f43e9c2 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -1462,6 +1462,8 @@  static inline bool tcp_ao_mkt_overlap_v6(struct tcp_ao *cmd,
 	(TCP_AO_CMDF_CURR | TCP_AO_CMDF_NEXT | TCP_AO_CMDF_ACCEPT_ICMP)
 #define TCP_AO_CMDF_DEL_VALID						\
 	(TCP_AO_CMDF_CURR | TCP_AO_CMDF_NEXT)
+#define TCP_AO_GETF_VALID						\
+	(TCP_AO_GET_ALL | TCP_AO_GET_CURR | TCP_AO_GET_NEXT)
 
 static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
 			  sockptr_t optval, int optlen)
@@ -1738,3 +1740,224 @@  int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen)
 	return tcp_parse_ao(sk, cmd, AF_INET, optval, optlen);
 }
 
+/* tcp_ao_copy_mkts_to_user(ao_info, optval, optlen)
+ *
+ * @ao_info:	struct tcp_ao_info on the socket that
+ *		socket getsockopt(TCP_AO_GET) is executed on
+ * @optval:	pointer to array of tcp_ao_getsockopt structures in user space.
+ *		Must be != NULL.
+ * @optlen:	pointer to size of tcp_ao_getsockopt structure.
+ *		Must be != NULL.
+ *
+ * Return value: 0 on success, a negative error number otherwise.
+ *
+ * optval points to an array of tcp_ao_getsockopt structures in user space.
+ * optval[0] is used as both input and output to getsockopt. It determines
+ * which keys are returned by the kernel.
+ * optval[0].nkeys is the size of the array in user space. On return it contains
+ * the number of keys matching the search criteria.
+ * If TCP_AO_GET_ALL is set in "flags", then all keys in the socket are
+ * returned, otherwise only keys matching <addr, prefix, sndid, rcvid>
+ * in optval[0] are returned.
+ * optlen is also used as both input and output. The user provides the size
+ * of struct tcp_ao_getsockopt in user space, and the kernel returns the size
+ * of the structure in kernel space.
+ * The size of struct tcp_ao_getsockopt may differ between user and kernel.
+ * There are three cases to consider:
+ *  * If usize == ksize, then keys are copied verbatim.
+ *  * If usize < ksize, then the userspace has passed an old struct to a
+ *    newer kernel. The rest of the trailing bytes in optval[0]
+ *    (ksize - usize) are interpreted as 0 by the kernel.
+ *  * If usize > ksize, then the userspace has passed a new struct to an
+ *    older kernel. The trailing bytes unknown to the kernel (usize - ksize)
+ *    are checked to ensure they are zeroed, otherwise -E2BIG is returned.
+ * On return the kernel fills in min(usize, ksize) in each entry of the array.
+ * The layout of the fields in the user and kernel structures is expected to
+ * be the same (including in the 32bit vs 64bit case).
+ */
+int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
+			     char __user *optval, int __user *optlen)
+{
+	struct tcp_ao_getsockopt opt_in;
+	struct tcp_ao_getsockopt opt_out;
+	struct tcp_ao_getsockopt __user *optval_in;
+	int user_len;
+	unsigned int max_keys;	/* maximum number of keys to copy to user */
+	u32 copied_keys;	/* keys copied to user so far */
+	int matched_keys;	/* keys from ao_info matched so far */
+	int bytes_to_write;	/* number of bytes to write to user level */
+	struct tcp_ao_key *key;
+	struct sockaddr_in *sin;   /* (struct sockaddr_in *)&opt_in.addr */
+	struct sockaddr_in6 *sin6; /* (struct sockaddr_in6 *)&opt_in.addr */
+	struct in6_addr *addr6;    /* &sin6->sin6_addr */
+	__kernel_sa_family_t ss_family;
+	union tcp_ao_addr *addr;
+	int optlen_out;
+	u8 prefix_in;
+	u16 port = 0;
+	bool copy_all, copy_current, copy_next;
+	int err;
+
+	if (get_user(user_len, optlen))
+		return -EFAULT;
+
+	if (user_len <= 0)
+		return -EINVAL;
+
+	memset(&opt_in, 0, sizeof(struct tcp_ao_getsockopt));
+	err = copy_struct_from_user(&opt_in, sizeof(struct tcp_ao_getsockopt),
+				    optval, user_len);
+	if (err < 0)
+		return err;
+
+	optval_in = (struct tcp_ao_getsockopt __user *)optval;
+	ss_family = opt_in.addr.ss_family;
+
+	BUILD_BUG_ON(TCP_AO_GET_ALL & (TCP_AO_GET_CURR | TCP_AO_GET_NEXT));
+	if (opt_in.flags & ~TCP_AO_GETF_VALID)
+		return -EINVAL;
+
+	max_keys = opt_in.nkeys;
+	copy_all = !!(opt_in.flags & TCP_AO_GET_ALL);
+	copy_current = !!(opt_in.flags & TCP_AO_GET_CURR);
+	copy_next = !!(opt_in.flags & TCP_AO_GET_NEXT);
+
+	if (!(copy_all || copy_current || copy_next)) {
+		prefix_in = opt_in.prefix;
+
+		switch (ss_family) {
+		case AF_INET: {
+			sin = (struct sockaddr_in *)&opt_in.addr;
+			port = sin->sin_port;
+			addr = (union tcp_ao_addr *)&sin->sin_addr;
+
+			if (prefix_in > 32)
+				return -EINVAL;
+
+			if (sin->sin_addr.s_addr == INADDR_ANY &&
+			    prefix_in != 0)
+				return -EINVAL;
+
+			break;
+		}
+		case AF_INET6: {
+			sin6 = (struct sockaddr_in6 *)&opt_in.addr;
+			addr = (union tcp_ao_addr *)&sin6->sin6_addr;
+			addr6 = &sin6->sin6_addr;
+			port = sin6->sin6_port;
+
+			if (prefix_in != 0) {
+				if (ipv6_addr_v4mapped(addr6)) {
+					__be32 addr4 = addr6->s6_addr32[3];
+
+					if (prefix_in > 32 ||
+					    addr4 == INADDR_ANY)
+						return -EINVAL;
+				} else {
+					if (ipv6_addr_any(addr6) ||
+					    prefix_in > 128)
+						return -EINVAL;
+				}
+			} else if (!ipv6_addr_any(addr6)) {
+				return -EINVAL;
+			}
+
+			break;
+		}
+		default:
+			return -EINVAL;
+		}
+	}
+
+	bytes_to_write = min(user_len, (int)sizeof(struct tcp_ao_getsockopt));
+	copied_keys = 0;
+	matched_keys = 0;
+
+	hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+		if (copy_all)
+			goto match;
+
+		if (copy_current || copy_next) {
+			if (copy_current && key == ao_info->current_key)
+				goto match;
+			if (copy_next && key == ao_info->rnext_key)
+				goto match;
+			continue;
+		}
+
+		if (tcp_ao_key_cmp(key, addr, opt_in.prefix,
+				   opt_in.addr.ss_family,
+				   opt_in.sndid, opt_in.rcvid, port) != 0)
+			continue;
+match:
+		matched_keys++;
+		if (copied_keys >= max_keys)
+			continue;
+
+		memset(&opt_out, 0, sizeof(struct tcp_ao_getsockopt));
+
+		if (key->family == AF_INET) {
+			struct sockaddr_in *sin_out = (struct sockaddr_in *)&opt_out.addr;
+
+			sin_out->sin_family = key->family;
+			sin_out->sin_port = ntohs(key->port);
+			memcpy(&sin_out->sin_addr, &key->addr, sizeof(struct in_addr));
+		} else {
+			struct sockaddr_in6 *sin6_out = (struct sockaddr_in6 *)&opt_out.addr;
+
+			sin6_out->sin6_family = key->family;
+			sin6_out->sin6_port = ntohs(key->port);
+			memcpy(&sin6_out->sin6_addr, &key->addr, sizeof(struct in6_addr));
+		}
+		opt_out.sndid = key->sndid;
+		opt_out.rcvid = key->rcvid;
+		opt_out.prefix = key->prefixlen;
+		opt_out.keyflags = key->keyflags;
+		opt_out.flags = 0;
+		if (key == ao_info->current_key)
+			opt_out.flags |= TCP_AO_GET_CURR;
+		if (key == ao_info->rnext_key)
+			opt_out.flags |= TCP_AO_GET_NEXT;
+		opt_out.nkeys = 0;
+		opt_out.maclen = key->maclen;
+		opt_out.keylen = key->keylen;
+		memcpy(&opt_out.key, key->key, key->keylen);
+		crypto_pool_algo(key->crypto_pool_id, opt_out.alg_name, 64);
+
+		/* Copy key to user */
+		if (copy_to_user(optval, &opt_out, bytes_to_write))
+			return -EFAULT;
+		optval += user_len;
+		copied_keys++;
+	}
+
+	optlen_out = (int)sizeof(struct tcp_ao_getsockopt);
+	if (copy_to_user(optlen, &optlen_out, sizeof(int)))
+		return -EFAULT;
+
+	if (copy_to_user(&optval_in->nkeys, &matched_keys, sizeof(u32)))
+		return -EFAULT;
+
+	return 0;
+}
+
+int tcp_ao_get_mkts(struct sock *sk, char __user *optval, int __user *optlen)
+{
+	struct tcp_ao_info *ao_info;
+	u32 state;
+
+	/* Check socket state */
+	state = (1 << sk->sk_state) &
+		(TCPF_CLOSE | TCPF_ESTABLISHED | TCPF_LISTEN);
+	if (!state)
+		return -ESOCKTNOSUPPORT;
+
+	/* Check ao_info */
+	ao_info = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+					    lockdep_sock_is_held(sk));
+	if (!ao_info)
+		return -ENOENT;
+
+	return tcp_ao_copy_mkts_to_user(ao_info, optval, optlen);
+}
+