Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/klassert/ipsec-next

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2020-10-02

1) Add a full xfrm compatible layer for 32-bit applications on
   64-bit kernels. From Dmitry Safonov.

Please pull or let me know if there are problems.
====================

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

MAINTAINERS

@@ -12158,6 +12158,7 @@ F:	net/ipv6/ipcomp6.c
 F:	net/ipv6/xfrm*
 F:	net/key/
 F:	net/xfrm/
+F:	tools/testing/selftests/net/ipsec.c
 
 NETWORKING [IPv4/IPv6]
 M:	"David S. Miller" <davem@davemloft.net>

include/net/xfrm.h

@@ -2000,6 +2000,39 @@ static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
 	return 0;
 }
 
+extern const int xfrm_msg_min[XFRM_NR_MSGTYPES];
+extern const struct nla_policy xfrma_policy[XFRMA_MAX+1];
+
+struct xfrm_translator {
+	/* Allocate frag_list and put compat translation there */
+	int (*alloc_compat)(struct sk_buff *skb, const struct nlmsghdr *src);
+
+	/* Allocate nlmsg with 64-bit translaton of received 32-bit message */
+	struct nlmsghdr *(*rcv_msg_compat)(const struct nlmsghdr *nlh,
+			int maxtype, const struct nla_policy *policy,
+			struct netlink_ext_ack *extack);
+
+	/* Translate 32-bit user_policy from sockptr */
+	int (*xlate_user_policy_sockptr)(u8 **pdata32, int optlen);
+
+	struct module *owner;
+};
+
+#if IS_ENABLED(CONFIG_XFRM_USER_COMPAT)
+extern int xfrm_register_translator(struct xfrm_translator *xtr);
+extern int xfrm_unregister_translator(struct xfrm_translator *xtr);
+extern struct xfrm_translator *xfrm_get_translator(void);
+extern void xfrm_put_translator(struct xfrm_translator *xtr);
+#else
+static inline struct xfrm_translator *xfrm_get_translator(void)
+{
+	return NULL;
+}
+static inline void xfrm_put_translator(struct xfrm_translator *xtr)
+{
+}
+#endif
+
 #if IS_ENABLED(CONFIG_IPV6)
 static inline bool xfrm6_local_dontfrag(const struct sock *sk)
 {

net/netlink/af_netlink.c

@@ -2186,13 +2186,35 @@ EXPORT_SYMBOL(__nlmsg_put);
  * It would be better to create kernel thread.
  */
 
+static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb,
+			     struct netlink_callback *cb,
+			     struct netlink_ext_ack *extack)
+{
+	struct nlmsghdr *nlh;
+
+	nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno),
+			       NLM_F_MULTI | cb->answer_flags);
+	if (WARN_ON(!nlh))
+		return -ENOBUFS;
+
+	nl_dump_check_consistent(cb, nlh);
+	memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno));
+
+	if (extack->_msg && nlk->flags & NETLINK_F_EXT_ACK) {
+		nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
+		if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg))
+			nlmsg_end(skb, nlh);
+	}
+
+	return 0;
+}
+
 static int netlink_dump(struct sock *sk)
 {
 	struct netlink_sock *nlk = nlk_sk(sk);
 	struct netlink_ext_ack extack = {};
 	struct netlink_callback *cb;
 	struct sk_buff *skb = NULL;
-	struct nlmsghdr *nlh;
 	struct module *module;
 	int err = -ENOBUFS;
 	int alloc_min_size;
@@ -2258,22 +2280,19 @@ static int netlink_dump(struct sock *sk)
 		return 0;
 	}
 
-	nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE,
-			       sizeof(nlk->dump_done_errno),
-			       NLM_F_MULTI | cb->answer_flags);
-	if (WARN_ON(!nlh))
+	if (netlink_dump_done(nlk, skb, cb, &extack))
 		goto errout_skb;
 
-	nl_dump_check_consistent(cb, nlh);
-
-	memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
-	       sizeof(nlk->dump_done_errno));
-
-	if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {
-		nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
-		if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))
-			nlmsg_end(skb, nlh);
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+	/* frag_list skb's data is used for compat tasks
+	 * and the regular skb's data for normal (non-compat) tasks.
+	 * See netlink_recvmsg().
+	 */
+	if (unlikely(skb_shinfo(skb)->frag_list)) {
+		if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack))
+			goto errout_skb;
 	}
+#endif
 
 	if (sk_filter(sk, skb))
 		kfree_skb(skb);

net/xfrm/Kconfig

@@ -28,6 +28,17 @@ config XFRM_USER
 
 	  If unsure, say Y.
 
+config XFRM_USER_COMPAT
+	tristate "Compatible ABI support"
+	depends on XFRM_USER && COMPAT_FOR_U64_ALIGNMENT && \
+		HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select WANT_COMPAT_NETLINK_MESSAGES
+	help
+	  Transformation(XFRM) user configuration interface like IPsec
+	  used by compatible Linux applications.
+
+	  If unsure, say N.
+
 config XFRM_INTERFACE
 	tristate "Transformation virtual interface"
 	depends on XFRM && IPV6

net/xfrm/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
 obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
 obj-$(CONFIG_XFRM_ALGO) += xfrm_algo.o
 obj-$(CONFIG_XFRM_USER) += xfrm_user.o
+obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o
 obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
 obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o
 obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o