Merge branch 'netlink_ext_ACK'

Johannes Berg says:

====================
netlink extended ACK reporting

Changes since v4:
 * use __NLMSGERR_ATTR_MAX instead of NUM_NLMSGERR_ATTRS

Changes since v3:
 * Add NLM_F_CAPPED and NLM_F_ACK_TLVS flags, to allow entirely
   stateless parsing of the ACK messages by looking at the new
   flags. Need to check NLM_F_ACK_TLVS first, since capping can
   be done in kernels before this patchset without setting the
   flag.
 * Remove "missing_attr" functionality - this can obviously be
   added back rather easily, but I'd rather have more discussion
   about the nesting problem there.
 * Improve documentation of NLMSGERR_ATTR_OFFS
 * Improve message structure documentation, documenting that the
   request message is always capped for success cases
 * fix nlmsg_len of the outer message by calling nlmsg_end()
 * fix memcpy() of the request in success cases, going back to
   the original code that I'd changed before due to the payload
   adjustments that I reverted when introducing tlvlen

Changes since v2:
 * add NUM_NLMSGERR_ATTRS, NLMSGERR_ATTR_MAX
 * fix cookie length to 20 (sha-1 length)
 * move struct members for cookie to patch 3 where they should be
 * another cleanup suggested by David Ahern

Changes since v1:
 * credit Pablo and Jamal
 * incorporate suggestion from David Ahern
 * fix compilation in decnet
====================

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

6 files changed, 41 insertions, 33 deletions

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 816e3ccb0ec9..df03110ca3c8 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -386,7 +386,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh)
 		goto errout;
 	}
 
-	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
+	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, NULL);
 	if (err < 0)
 		goto errout;
 
@@ -580,7 +580,7 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh)
 		goto errout;
 	}
 
-	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
+	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, NULL);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index 0cfe7b0216c3..b3bc0a31af9f 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -209,7 +209,8 @@ static int bpf_parse_prog(struct nlattr *attr, struct bpf_lwt_prog *prog,
 	int ret;
 	u32 fd;
 
-	ret = nla_parse_nested(tb, LWT_BPF_PROG_MAX, attr, bpf_prog_policy);
+	ret = nla_parse_nested(tb, LWT_BPF_PROG_MAX, attr, bpf_prog_policy,
+			       NULL);
 	if (ret < 0)
 		return ret;
 
@@ -249,7 +250,7 @@ static int bpf_build_state(struct nlattr *nla,
 	if (family != AF_INET && family != AF_INET6)
 		return -EAFNOSUPPORT;
 
-	ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy);
+	ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy, NULL);
 	if (ret < 0)
 		return ret;
 
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 8ae87c591c8e..31f37b264710 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1661,7 +1661,7 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int err;
 
 	ASSERT_RTNL();
-	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, NULL);
 	if (err < 0)
 		goto out;
 
@@ -1946,7 +1946,7 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int err, tidx;
 
 	err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
-			  nl_neightbl_policy);
+			  nl_neightbl_policy, NULL);
 	if (err < 0)
 		goto errout;
 
@@ -1984,7 +1984,7 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
 		int i, ifindex = 0;
 
 		err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
-				       nl_ntbl_parm_policy);
+				       nl_ntbl_parm_policy, NULL);
 		if (err < 0)
 			goto errout_tbl_lock;
 
@@ -2275,7 +2275,7 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
 	unsigned int flags = NLM_F_MULTI;
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL);
+	err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL, NULL);
 	if (!err) {
 		if (tb[NDA_IFINDEX])
 			filter_idx = nla_get_u32(tb[NDA_IFINDEX]);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 652468ff65b7..ec18cbc756d2 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -579,7 +579,7 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int nsid, err;
 
 	err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
-			  rtnl_net_policy);
+			  rtnl_net_policy, NULL);
 	if (err < 0)
 		return err;
 	if (!tb[NETNSA_NSID])
@@ -653,7 +653,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int err, id;
 
 	err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
-			  rtnl_net_policy);
+			  rtnl_net_policy, NULL);
 	if (err < 0)
 		return err;
 	if (tb[NETNSA_PID])
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index c138b6b75e59..0ee5479528b5 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1515,7 +1515,8 @@ static const struct rtnl_link_ops *linkinfo_to_kind_ops(const struct nlattr *nla
 	const struct rtnl_link_ops *ops = NULL;
 	struct nlattr *linfo[IFLA_INFO_MAX + 1];
 
-	if (nla_parse_nested(linfo, IFLA_INFO_MAX, nla, ifla_info_policy) < 0)
+	if (nla_parse_nested(linfo, IFLA_INFO_MAX, nla,
+			     ifla_info_policy, NULL) < 0)
 		return NULL;
 
 	if (linfo[IFLA_INFO_KIND]) {
@@ -1592,8 +1593,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 	hdrlen = nlmsg_len(cb->nlh) < sizeof(struct ifinfomsg) ?
 		 sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
 
-	if (nlmsg_parse(cb->nlh, hdrlen, tb, IFLA_MAX, ifla_policy) >= 0) {
-
+	if (nlmsg_parse(cb->nlh, hdrlen, tb, IFLA_MAX,
+			ifla_policy, NULL) >= 0) {
 		if (tb[IFLA_EXT_MASK])
 			ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
 
@@ -1640,9 +1641,10 @@ out:
 	return skb->len;
 }
 
-int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len)
+int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len,
+			struct netlink_ext_ack *exterr)
 {
-	return nla_parse(tb, IFLA_MAX, head, len, ifla_policy);
+	return nla_parse(tb, IFLA_MAX, head, len, ifla_policy, exterr);
 }
 EXPORT_SYMBOL(rtnl_nla_parse_ifla);
 
@@ -2078,7 +2080,7 @@ static int do_setlink(const struct sk_buff *skb,
 				goto errout;
 			}
 			err = nla_parse_nested(vfinfo, IFLA_VF_MAX, attr,
-					       ifla_vf_policy);
+					       ifla_vf_policy, NULL);
 			if (err < 0)
 				goto errout;
 			err = do_setvfinfo(dev, vfinfo);
@@ -2106,7 +2108,7 @@ static int do_setlink(const struct sk_buff *skb,
 				goto errout;
 			}
 			err = nla_parse_nested(port, IFLA_PORT_MAX, attr,
-					       ifla_port_policy);
+					       ifla_port_policy, NULL);
 			if (err < 0)
 				goto errout;
 			if (!port[IFLA_PORT_VF]) {
@@ -2126,7 +2128,8 @@ static int do_setlink(const struct sk_buff *skb,
 		struct nlattr *port[IFLA_PORT_MAX+1];
 
 		err = nla_parse_nested(port, IFLA_PORT_MAX,
-			tb[IFLA_PORT_SELF], ifla_port_policy);
+				       tb[IFLA_PORT_SELF], ifla_port_policy,
+				       NULL);
 		if (err < 0)
 			goto errout;
 
@@ -2170,7 +2173,7 @@ static int do_setlink(const struct sk_buff *skb,
 		u32 xdp_flags = 0;
 
 		err = nla_parse_nested(xdp, IFLA_XDP_MAX, tb[IFLA_XDP],
-				       ifla_xdp_policy);
+				       ifla_xdp_policy, NULL);
 		if (err < 0)
 			goto errout;
 
@@ -2219,7 +2222,7 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct nlattr *tb[IFLA_MAX+1];
 	char ifname[IFNAMSIZ];
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
 	if (err < 0)
 		goto errout;
 
@@ -2312,7 +2315,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct nlattr *tb[IFLA_MAX+1];
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
 	if (err < 0)
 		return err;
 
@@ -2441,7 +2444,7 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh)
 #ifdef CONFIG_MODULES
 replay:
 #endif
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
 	if (err < 0)
 		return err;
 
@@ -2472,7 +2475,8 @@ replay:
 
 	if (tb[IFLA_LINKINFO]) {
 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
-				       tb[IFLA_LINKINFO], ifla_info_policy);
+				       tb[IFLA_LINKINFO], ifla_info_policy,
+				       NULL);
 		if (err < 0)
 			return err;
 	} else
@@ -2497,7 +2501,7 @@ replay:
 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
 				err = nla_parse_nested(attr, ops->maxtype,
 						       linkinfo[IFLA_INFO_DATA],
-						       ops->policy);
+						       ops->policy, NULL);
 				if (err < 0)
 					return err;
 				data = attr;
@@ -2515,7 +2519,8 @@ replay:
 				err = nla_parse_nested(slave_attr,
 						       m_ops->slave_maxtype,
 						       linkinfo[IFLA_INFO_SLAVE_DATA],
-						       m_ops->slave_policy);
+						       m_ops->slave_policy,
+						       NULL);
 				if (err < 0)
 					return err;
 				slave_data = slave_attr;
@@ -2684,7 +2689,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh)
 	int err;
 	u32 ext_filter_mask = 0;
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
 	if (err < 0)
 		return err;
 
@@ -2734,7 +2739,7 @@ static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
 	hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ?
 		 sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
 
-	if (nlmsg_parse(nlh, hdrlen, tb, IFLA_MAX, ifla_policy) >= 0) {
+	if (nlmsg_parse(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) {
 		if (tb[IFLA_EXT_MASK])
 			ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
 	}
@@ -2965,7 +2970,7 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 	u16 vid;
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, NULL);
 	if (err < 0)
 		return err;
 
@@ -3068,7 +3073,7 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (!netlink_capable(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, NULL);
 	if (err < 0)
 		return err;
 
@@ -3203,8 +3208,8 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	int err = 0;
 	int fidx = 0;
 
-	if (nlmsg_parse(cb->nlh, sizeof(struct ifinfomsg), tb, IFLA_MAX,
-			ifla_policy) == 0) {
+	if (nlmsg_parse(cb->nlh, sizeof(struct ifinfomsg), tb,
+			IFLA_MAX, ifla_policy, NULL) == 0) {
 		if (tb[IFLA_MASTER])
 			br_idx = nla_get_u32(tb[IFLA_MASTER]);
 	}
@@ -4046,7 +4051,8 @@ out:
 
 /* Process one rtnetlink message. */
 
-static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	rtnl_doit_func doit;
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index fb9d0e2fd148..217f4e3b82f6 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -238,7 +238,8 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
 	return err;
 }
 
-static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
 {
 	int ret;