Merge branch 'mptcp-some-clean-up-patches'

Matthieu Baerts says:

====================
mptcp: some clean-up patches

Here are some clean-up patches for MPTCP:

- Patch 1 drops duplicated header inclusions.

- Patch 2 updates PM 'set_flags' interface, to make it more similar to
  others.

- Patch 3 adds some error messages for the PM 'set_flags' command to
  help the userspace understanding what's wrong in case of error.

- Patch 4 simplifies __lookup_addr() function from pm_netlink.c.

Except for the 3rd patch, the behaviour is not supposed to be modified.
====================

Link: https://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-0-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

8 files changed, 73 insertions, 69 deletions

diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c
index 7017dd60659d..3ae46b545d2c 100644
--- a/net/mptcp/diag.c
+++ b/net/mptcp/diag.c
@@ -10,7 +10,6 @@
 #include <linux/net.h>
 #include <linux/inet_diag.h>
 #include <net/netlink.h>
-#include <uapi/linux/mptcp.h>
 #include "protocol.h"
 
 static int subflow_get_info(struct sock *sk, struct sk_buff *skb)
diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c
index bd8ff5950c8d..0566dd793810 100644
--- a/net/mptcp/mptcp_diag.c
+++ b/net/mptcp/mptcp_diag.c
@@ -10,7 +10,6 @@
 #include <linux/net.h>
 #include <linux/inet_diag.h>
 #include <net/netlink.h>
-#include <uapi/linux/mptcp.h>
 #include "protocol.h"
 
 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index b4bdd92a5648..55406720c607 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -6,7 +6,6 @@
 #define pr_fmt(fmt) "MPTCP: " fmt
 
 #include <linux/kernel.h>
-#include <net/tcp.h>
 #include <net/mptcp.h>
 #include "protocol.h"
 
@@ -457,13 +456,11 @@ int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
 	return mptcp_pm_nl_dump_addr(msg, cb);
 }
 
-int mptcp_pm_set_flags(struct net *net, struct nlattr *token,
-		       struct mptcp_pm_addr_entry *loc,
-		       struct mptcp_pm_addr_entry *rem, u8 bkup)
+int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
-	if (token)
-		return mptcp_userspace_pm_set_flags(net, token, loc, rem, bkup);
-	return mptcp_pm_nl_set_flags(net, loc, bkup);
+	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
+		return mptcp_userspace_pm_set_flags(skb, info);
+	return mptcp_pm_nl_set_flags(skb, info);
 }
 
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 16f8bd47f4b8..5c17d39146ea 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -8,12 +8,9 @@
 
 #include <linux/inet.h>
 #include <linux/kernel.h>
-#include <net/tcp.h>
 #include <net/inet_common.h>
 #include <net/netns/generic.h>
 #include <net/mptcp.h>
-#include <net/genetlink.h>
-#include <uapi/linux/mptcp.h>
 
 #include "protocol.h"
 #include "mib.h"
@@ -502,15 +499,12 @@ __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 }
 
 static struct mptcp_pm_addr_entry *
-__lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
-	      bool lookup_by_id)
+__lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info)
 {
 	struct mptcp_pm_addr_entry *entry;
 
 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
-		if ((!lookup_by_id &&
-		     mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) ||
-		    (lookup_by_id && entry->addr.id == info->id))
+		if (mptcp_addresses_equal(&entry->addr, info, entry->addr.port))
 			return entry;
 	}
 	return NULL;
@@ -540,7 +534,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 
 		mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
 		rcu_read_lock();
-		entry = __lookup_addr(pernet, &mpc_addr, false);
+		entry = __lookup_addr(pernet, &mpc_addr);
 		if (entry) {
 			__clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
 			msk->mpc_endpoint_id = entry->addr.id;
@@ -1890,66 +1884,63 @@ next:
 	return ret;
 }
 
-int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup)
+int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
-	struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
+	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
 			   MPTCP_PM_ADDR_FLAG_FULLMESH;
+	struct net *net = sock_net(skb->sk);
 	struct mptcp_pm_addr_entry *entry;
+	struct pm_nl_pernet *pernet;
 	u8 lookup_by_id = 0;
+	u8 bkup = 0;
+	int ret;
+
+	pernet = pm_nl_get_pernet(net);
 
-	if (addr->addr.family == AF_UNSPEC) {
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
+	if (ret < 0)
+		return ret;
+
+	if (addr.addr.family == AF_UNSPEC) {
 		lookup_by_id = 1;
-		if (!addr->addr.id)
+		if (!addr.addr.id) {
+			GENL_SET_ERR_MSG(info, "missing required inputs");
 			return -EOPNOTSUPP;
+		}
 	}
 
+	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+		bkup = 1;
+
 	spin_lock_bh(&pernet->lock);
-	entry = __lookup_addr(pernet, &addr->addr, lookup_by_id);
+	entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
+			       __lookup_addr(pernet, &addr.addr);
 	if (!entry) {
 		spin_unlock_bh(&pernet->lock);
+		GENL_SET_ERR_MSG(info, "address not found");
 		return -EINVAL;
 	}
-	if ((addr->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
+	if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
 	    (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
 		spin_unlock_bh(&pernet->lock);
+		GENL_SET_ERR_MSG(info, "invalid addr flags");
 		return -EINVAL;
 	}
 
-	changed = (addr->flags ^ entry->flags) & mask;
-	entry->flags = (entry->flags & ~mask) | (addr->flags & mask);
-	*addr = *entry;
+	changed = (addr.flags ^ entry->flags) & mask;
+	entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
+	addr = *entry;
 	spin_unlock_bh(&pernet->lock);
 
-	mptcp_nl_set_flags(net, &addr->addr, bkup, changed);
+	mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
 	return 0;
 }
 
 int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
-	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
-	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
-	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
-	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
-	struct net *net = sock_net(skb->sk);
-	u8 bkup = 0;
-	int ret;
-
-	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
-	if (ret < 0)
-		return ret;
-
-	if (attr_rem) {
-		ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
-		if (ret < 0)
-			return ret;
-	}
-
-	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
-		bkup = 1;
-
-	return mptcp_pm_set_flags(net, token, &addr, &remote, bkup);
+	return mptcp_pm_set_flags(skb, info);
 }
 
 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index b9809d988693..9f5d422d5ef6 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -546,32 +546,57 @@ destroy_err:
 	return err;
 }
 
-int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
-				 struct mptcp_pm_addr_entry *loc,
-				 struct mptcp_pm_addr_entry *rem, u8 bkup)
+int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
+	struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, };
+	struct mptcp_pm_addr_entry rem = { .addr = { .family = AF_UNSPEC }, };
+	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct net *net = sock_net(skb->sk);
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
 	struct sock *sk;
 	u32 token_val;
+	u8 bkup = 0;
 
 	token_val = nla_get_u32(token);
 
 	msk = mptcp_token_get_sock(net, token_val);
-	if (!msk)
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 		return ret;
+	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk))
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "userspace PM not selected");
+		goto set_flags_err;
+	}
+
+	ret = mptcp_pm_parse_entry(attr, info, false, &loc);
+	if (ret < 0)
 		goto set_flags_err;
 
-	if (loc->addr.family == AF_UNSPEC ||
-	    rem->addr.family == AF_UNSPEC)
+	if (attr_rem) {
+		ret = mptcp_pm_parse_entry(attr_rem, info, false, &rem);
+		if (ret < 0)
+			goto set_flags_err;
+	}
+
+	if (loc.addr.family == AF_UNSPEC ||
+	    rem.addr.family == AF_UNSPEC) {
+		GENL_SET_ERR_MSG(info, "invalid address families");
+		ret = -EINVAL;
 		goto set_flags_err;
+	}
+
+	if (loc.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+		bkup = 1;
 
 	lock_sock(sk);
-	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
+	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc.addr, &rem.addr, bkup);
 	release_sock(sk);
 
 set_flags_err:
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 99367c40de0d..3a1967bc7bad 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -15,7 +15,6 @@
 #include <net/inet_common.h>
 #include <net/inet_hashtables.h>
 #include <net/protocol.h>
-#include <net/tcp.h>
 #include <net/tcp_states.h>
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 #include <net/transp_v6.h>
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index de9f0ff6dd30..f16edef6026a 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -970,13 +970,9 @@ int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int
 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 						   unsigned int id,
 						   u8 *flags, int *ifindex);
-int mptcp_pm_set_flags(struct net *net, struct nlattr *token,
-		       struct mptcp_pm_addr_entry *loc,
-		       struct mptcp_pm_addr_entry *rem, u8 bkup);
-int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup);
-int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
-				 struct mptcp_pm_addr_entry *loc,
-				 struct mptcp_pm_addr_entry *rem, u8 bkup);
+int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
+int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info);
+int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   const struct mptcp_addr_info *addr,
 			   bool echo);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 6403c56f2902..1626dd20c68f 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -15,13 +15,11 @@
 #include <net/inet_common.h>
 #include <net/inet_hashtables.h>
 #include <net/protocol.h>
-#include <net/tcp.h>
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 #include <net/ip6_route.h>
 #include <net/transp_v6.h>
 #endif
 #include <net/mptcp.h>
-#include <uapi/linux/mptcp.h>
 #include "protocol.h"
 #include "mib.h"