Merge branch 'mptcp-fixes-and-cleanup-for-v6-7'

Mat Martineau says:

====================
mptcp: Fixes and cleanup for v6.7

This series includes three initial patches that we had queued in our
mptcp-net branch, but given the likely timing of net/net-next syncs this
week, the need to avoid introducing branch conflicts, and another batch
of net-next patches pending in the mptcp tree, the most practical route
is to send everything for net-next.

Patches 1 & 2 fix some intermittent selftest failures by adjusting timing.

Patch 3 removes an unneccessary userspace path manager restriction on
the removal of subflows with subflow ID 0.

The remainder of the patches are all cleanup or selftest changes:

Patches 4-8 clean up kernel code by removing unused parameters, making
more consistent use of existing helper functions, and reducing extra
casting of socket pointers.

Patch 9 removes an unused variable in a selftest script.

Patch 10 adds a little more detail to some mptcp_join test output.
====================

Link: https://lore.kernel.org/r/20231025-send-net-next-20231025-v1-0-db8f25f798eb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 88 insertions, 31 deletions

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index d8da5374d9e1..4ae19113b8eb 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -184,7 +184,7 @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk)
 	spin_unlock_bh(&pm->lock);
 }
 
-void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
+void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 				 const struct mptcp_subflow_context *subflow)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 0f92e5b13a8a..5c01b9bc619a 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -152,6 +152,7 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 	struct mptcp_pm_addr_entry addr_val;
 	struct mptcp_sock *msk;
 	int err = -EINVAL;
+	struct sock *sk;
 	u32 token_val;
 
 	if (!addr || !token) {
@@ -167,6 +168,8 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 		return err;
 	}
 
+	sk = (struct sock *)msk;
+
 	if (!mptcp_pm_is_userspace(msk)) {
 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 		goto announce_err;
@@ -190,7 +193,7 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 		goto announce_err;
 	}
 
-	lock_sock((struct sock *)msk);
+	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
 
 	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
@@ -200,11 +203,45 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	spin_unlock_bh(&msk->pm.lock);
-	release_sock((struct sock *)msk);
+	release_sock(sk);
 
 	err = 0;
  announce_err:
-	sock_put((struct sock *)msk);
+	sock_put(sk);
+	return err;
+}
+
+static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
+						     struct genl_info *info)
+{
+	struct mptcp_rm_list list = { .nr = 0 };
+	struct mptcp_subflow_context *subflow;
+	struct sock *sk = (struct sock *)msk;
+	bool has_id_0 = false;
+	int err = -EINVAL;
+
+	lock_sock(sk);
+	mptcp_for_each_subflow(msk, subflow) {
+		if (subflow->local_id == 0) {
+			has_id_0 = true;
+			break;
+		}
+	}
+	if (!has_id_0) {
+		GENL_SET_ERR_MSG(info, "address with id 0 not found");
+		goto remove_err;
+	}
+
+	list.ids[list.nr++] = 0;
+
+	spin_lock_bh(&msk->pm.lock);
+	mptcp_pm_remove_addr(msk, &list);
+	spin_unlock_bh(&msk->pm.lock);
+
+	err = 0;
+
+remove_err:
+	release_sock(sk);
 	return err;
 }
 
@@ -217,6 +254,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	struct mptcp_sock *msk;
 	LIST_HEAD(free_list);
 	int err = -EINVAL;
+	struct sock *sk;
 	u32 token_val;
 	u8 id_val;
 
@@ -234,12 +272,19 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 		return err;
 	}
 
+	sk = (struct sock *)msk;
+
 	if (!mptcp_pm_is_userspace(msk)) {
 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 		goto remove_err;
 	}
 
-	lock_sock((struct sock *)msk);
+	if (id_val == 0) {
+		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
+		goto remove_err;
+	}
+
+	lock_sock(sk);
 
 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 		if (entry->addr.id == id_val) {
@@ -250,7 +295,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 
 	if (!match) {
 		GENL_SET_ERR_MSG(info, "address with specified id not found");
-		release_sock((struct sock *)msk);
+		release_sock(sk);
 		goto remove_err;
 	}
 
@@ -258,15 +303,15 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 
 	mptcp_pm_remove_addrs(msk, &free_list);
 
-	release_sock((struct sock *)msk);
+	release_sock(sk);
 
 	list_for_each_entry_safe(match, entry, &free_list, list) {
-		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
+		sock_kfree_s(sk, match, sizeof(*match));
 	}
 
 	err = 0;
  remove_err:
-	sock_put((struct sock *)msk);
+	sock_put(sk);
 	return err;
 }
 
@@ -296,6 +341,8 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 		return err;
 	}
 
+	sk = (struct sock *)msk;
+
 	if (!mptcp_pm_is_userspace(msk)) {
 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 		goto create_err;
@@ -313,8 +360,6 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 		goto create_err;
 	}
 
-	sk = (struct sock *)msk;
-
 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 		GENL_SET_ERR_MSG(info, "families mismatch");
 		err = -EINVAL;
@@ -342,7 +387,7 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 	spin_unlock_bh(&msk->pm.lock);
 
  create_err:
-	sock_put((struct sock *)msk);
+	sock_put(sk);
 	return err;
 }
 
@@ -419,6 +464,8 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 		return err;
 	}
 
+	sk = (struct sock *)msk;
+
 	if (!mptcp_pm_is_userspace(msk)) {
 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 		goto destroy_err;
@@ -448,7 +495,6 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 		goto destroy_err;
 	}
 
-	sk = (struct sock *)msk;
 	lock_sock(sk);
 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 	if (ssk) {
@@ -468,7 +514,7 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 	release_sock(sk);
 
 destroy_err:
-	sock_put((struct sock *)msk);
+	sock_put(sk);
 	return err;
 }
 
@@ -478,6 +524,7 @@ int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 {
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
+	struct sock *sk;
 	u32 token_val;
 
 	token_val = nla_get_u32(token);
@@ -486,6 +533,8 @@ int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 	if (!msk)
 		return ret;
 
+	sk = (struct sock *)msk;
+
 	if (!mptcp_pm_is_userspace(msk))
 		goto set_flags_err;
 
@@ -493,11 +542,11 @@ int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 	    rem->addr.family == AF_UNSPEC)
 		goto set_flags_err;
 
-	lock_sock((struct sock *)msk);
+	lock_sock(sk);
 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
-	release_sock((struct sock *)msk);
+	release_sock(sk);
 
 set_flags_err:
-	sock_put((struct sock *)msk);
+	sock_put(sk);
 	return ret;
 }
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1dacc072dcca..a0b8356cd8c5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1267,7 +1267,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 		 * queue management operation, to avoid breaking the ext <->
 		 * SSN association set here
 		 */
-		mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
+		mpext = mptcp_get_ext(skb);
 		if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
 			TCP_SKB_CB(skb)->eor = 1;
 			goto alloc_skb;
@@ -1289,7 +1289,7 @@ alloc_skb:
 
 		i = skb_shinfo(skb)->nr_frags;
 		reuse_skb = false;
-		mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
+		mpext = mptcp_get_ext(skb);
 	}
 
 	/* Zero window and all data acked? Probe. */
@@ -2490,7 +2490,7 @@ void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 	/* subflow aborted before reaching the fully_established status
 	 * attempt the creation of the next subflow
 	 */
-	mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow);
+	mptcp_pm_subflow_check_next(mptcp_sk(sk), subflow);
 
 	__mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH);
 }
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 9092fcf18798..fe6f2d399ee8 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -888,7 +888,7 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
 void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
-void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
+void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 				 const struct mptcp_subflow_context *subflow);
 void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr);
@@ -1065,7 +1065,7 @@ static inline bool mptcp_check_fallback(const struct sock *sk)
 
 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
 {
-	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
+	if (__mptcp_check_fallback(msk)) {
 		pr_debug("TCP fallback already done (msk=%p)", msk);
 		return;
 	}
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 574e221bb765..77f5e8932abf 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -916,7 +916,7 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
 			mptcp_pm_get_local_addr_max(msk);
 	}
 
-	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags))
+	if (__mptcp_check_fallback(msk))
 		flags |= MPTCP_INFO_FLAG_FALLBACK;
 	if (READ_ONCE(msk->can_ack))
 		flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED;
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index dc895b7b94e1..75a2438efdf3 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -1770,7 +1770,10 @@ chk_rm_nr()
 		# in case of simult flush, the subflow removal count on each side is
 		# unreliable
 		count=$((count + cnt))
-		[ "$count" != "$rm_subflow_nr" ] && suffix="$count in [$rm_subflow_nr:$((rm_subflow_nr*2))]"
+		if [ "$count" != "$rm_subflow_nr" ]; then
+			suffix="$count in [$rm_subflow_nr:$((rm_subflow_nr*2))]"
+			extra_msg="$extra_msg simult"
+		fi
 		if [ $count -ge "$rm_subflow_nr" ] && \
 		   [ "$count" -le "$((rm_subflow_nr *2 ))" ]; then
 			print_ok "$suffix"
@@ -3289,6 +3292,7 @@ userspace_pm_rm_sf_addr_ns1()
 	local addr=$1
 	local id=$2
 	local tk sp da dp
+	local cnt_addr cnt_sf
 
 	tk=$(grep "type:1," "$evts_ns1" |
 	     sed -n 's/.*\(token:\)\([[:digit:]]*\).*$/\2/p;q')
@@ -3298,11 +3302,13 @@ userspace_pm_rm_sf_addr_ns1()
 	     sed -n 's/.*\(daddr6:\)\([0-9a-f:.]*\).*$/\2/p;q')
 	dp=$(grep "type:10" "$evts_ns1" |
 	     sed -n 's/.*\(dport:\)\([[:digit:]]*\).*$/\2/p;q')
+	cnt_addr=$(rm_addr_count ${ns1})
+	cnt_sf=$(rm_sf_count ${ns1})
 	ip netns exec $ns1 ./pm_nl_ctl rem token $tk id $id
 	ip netns exec $ns1 ./pm_nl_ctl dsf lip "::ffff:$addr" \
 				lport $sp rip $da rport $dp token $tk
-	wait_rm_addr $ns1 1
-	wait_rm_sf $ns1 1
+	wait_rm_addr $ns1 "${cnt_addr}"
+	wait_rm_sf $ns1 "${cnt_sf}"
 }
 
 userspace_pm_add_sf()
@@ -3324,17 +3330,20 @@ userspace_pm_rm_sf_addr_ns2()
 	local addr=$1
 	local id=$2
 	local tk da dp sp
+	local cnt_addr cnt_sf
 
 	tk=$(sed -n 's/.*\(token:\)\([[:digit:]]*\).*$/\2/p;q' "$evts_ns2")
 	da=$(sed -n 's/.*\(daddr4:\)\([0-9.]*\).*$/\2/p;q' "$evts_ns2")
 	dp=$(sed -n 's/.*\(dport:\)\([[:digit:]]*\).*$/\2/p;q' "$evts_ns2")
 	sp=$(grep "type:10" "$evts_ns2" |
 	     sed -n 's/.*\(sport:\)\([[:digit:]]*\).*$/\2/p;q')
+	cnt_addr=$(rm_addr_count ${ns2})
+	cnt_sf=$(rm_sf_count ${ns2})
 	ip netns exec $ns2 ./pm_nl_ctl rem token $tk id $id
 	ip netns exec $ns2 ./pm_nl_ctl dsf lip $addr lport $sp \
 				rip $da rport $dp token $tk
-	wait_rm_addr $ns2 1
-	wait_rm_sf $ns2 1
+	wait_rm_addr $ns2 "${cnt_addr}"
+	wait_rm_sf $ns2 "${cnt_sf}"
 }
 
 userspace_tests()
@@ -3417,7 +3426,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns1
 		pm_nl_set_limits $ns2 1 1
-		speed=10 \
+		speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 &
 		local tests_pid=$!
 		wait_mpj $ns1
@@ -3438,7 +3447,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns2
 		pm_nl_set_limits $ns1 0 1
-		speed=10 \
+		speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 &
 		local tests_pid=$!
 		wait_mpj $ns2
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
index 8c8694f21e7d..a817af6616ec 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
@@ -11,7 +11,6 @@ cout=""
 ksft_skip=4
 timeout_poll=30
 timeout_test=$((timeout_poll * 2 + 1))
-mptcp_connect=""
 iptables="iptables"
 ip6tables="ip6tables"