Merge branch 'mptcp-more-misc-fixes-for-v6-8'

Matthieu Baerts says:

====================
mptcp: more misc. fixes for v6.8

This series includes 6 types of fixes:

- Patch 1 fixes v4 mapped in v6 addresses support for the userspace PM,
  when asking to delete a subflow. It was done everywhere else, but not
  there. Patch 2 validates the modification, thanks to a subtest in
  mptcp_join.sh. These patches can be backported up to v5.19.

- Patch 3 is a small fix for a recent bug-fix patch, just to avoid
  printing an irrelevant warning (pr_warn()) once. It can be backported
  up to v5.6, alongside the bug-fix that has been introduced in the
  v6.8-rc5.

- Patches 4 to 6 are fixes for bugs found by Paolo while working on
  TCP_NOTSENT_LOWAT support for MPTCP. These fixes can improve the
  performances in some cases. Patches can be backported up to v5.6,
  v5.11 and v6.7 respectively.

- Patch 7 makes sure 'ss -M' is available when starting MPTCP Join
  selftest as it is required for some subtests since v5.18.

- Patch 8 fixes a possible double-free on socket dismantle. The issue
  always existed, but was unnoticed because it was not causing any
  problem so far. This fix can be backported up to v5.6.

- Patch 9 is a fix for a very recent patch causing lockdep warnings in
  subflow diag. The patch causing the regression -- which fixes another
  issue present since v5.7 -- should be part of the future v6.8-rc6.
  Patch 10 validates the modification, thanks to a new subtest in
  diag.sh.
====================

Link: https://lore.kernel.org/r/20240223-upstream-net-20240223-misc-fixes-v1-0-162e87e48497@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 51 insertions, 1 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 948606a537da..7833a49f6214 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1260,6 +1260,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 		mpext = mptcp_get_ext(skb);
 		if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
 			TCP_SKB_CB(skb)->eor = 1;
+			tcp_mark_push(tcp_sk(ssk), skb);
 			goto alloc_skb;
 		}
 
@@ -3177,8 +3178,50 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
 
 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
 }
+
+static void mptcp_copy_ip6_options(struct sock *newsk, const struct sock *sk)
+{
+	const struct ipv6_pinfo *np = inet6_sk(sk);
+	struct ipv6_txoptions *opt;
+	struct ipv6_pinfo *newnp;
+
+	newnp = inet6_sk(newsk);
+
+	rcu_read_lock();
+	opt = rcu_dereference(np->opt);
+	if (opt) {
+		opt = ipv6_dup_options(newsk, opt);
+		if (!opt)
+			net_warn_ratelimited("%s: Failed to copy ip6 options\n", __func__);
+	}
+	RCU_INIT_POINTER(newnp->opt, opt);
+	rcu_read_unlock();
+}
 #endif
 
+static void mptcp_copy_ip_options(struct sock *newsk, const struct sock *sk)
+{
+	struct ip_options_rcu *inet_opt, *newopt = NULL;
+	const struct inet_sock *inet = inet_sk(sk);
+	struct inet_sock *newinet;
+
+	newinet = inet_sk(newsk);
+
+	rcu_read_lock();
+	inet_opt = rcu_dereference(inet->inet_opt);
+	if (inet_opt) {
+		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
+				      inet_opt->opt.optlen, GFP_ATOMIC);
+		if (newopt)
+			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
+			       inet_opt->opt.optlen);
+		else
+			net_warn_ratelimited("%s: Failed to copy ip options\n", __func__);
+	}
+	RCU_INIT_POINTER(newinet->inet_opt, newopt);
+	rcu_read_unlock();
+}
+
 struct sock *mptcp_sk_clone_init(const struct sock *sk,
 				 const struct mptcp_options_received *mp_opt,
 				 struct sock *ssk,
@@ -3199,6 +3242,13 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
 
 	__mptcp_init_sock(nsk);
 
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	if (nsk->sk_family == AF_INET6)
+		mptcp_copy_ip6_options(nsk, sk);
+	else
+#endif
+		mptcp_copy_ip_options(nsk, sk);
+
 	msk = mptcp_sk(nsk);
 	msk->local_key = subflow_req->local_key;
 	msk->token = subflow_req->token;
@@ -3210,7 +3260,7 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
 	msk->write_seq = subflow_req->idsn + 1;
 	msk->snd_nxt = msk->write_seq;
 	msk->snd_una = msk->write_seq;
-	msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
+	msk->wnd_end = msk->snd_nxt + tcp_sk(ssk)->snd_wnd;
 	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
 	mptcp_init_sched(msk, mptcp_sk(sk)->sched);