| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20210415234502.224225-6-mathew.j.martineau@linux.intel.com>
Date: Thu, 15 Apr 2021 16:44:54 -0700
From: Mat Martineau <mathew.j.martineau@...ux.intel.com>
To: netdev@...r.kernel.org
Cc: Florian Westphal <fw@...len.de>, davem@...emloft.net,
kuba@...nel.org, matthieu.baerts@...sares.net,
mptcp@...ts.linux.dev, Paolo Abeni <pabeni@...hat.com>,
Mat Martineau <mathew.j.martineau@...ux.intel.com>
Subject: [PATCH net-next 05/13] mptcp: tag sequence_seq with socket state
From: Florian Westphal <fw@...len.de>
Paolo Abeni suggested to avoid re-syncing new subflows because
they inherit options from listener. In case options were set on
listener but are not set on mptcp-socket there is no need to
do any synchronisation for new subflows.
This change sets sockopt_seq of new mptcp sockets to the seq of
the mptcp listener sock.
Subflow sequence is set to the embedded tcp listener sk.
Add a comment explaing why sk_state is involved in sockopt_seq
generation.
Acked-by: Paolo Abeni <pabeni@...hat.com>
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@...ux.intel.com>
---
net/mptcp/protocol.c | 12 ++++++++---
net/mptcp/protocol.h | 4 ++++
net/mptcp/sockopt.c | 47 ++++++++++++++++++++++++++++++++++++++++++--
net/mptcp/subflow.c | 4 ++++
4 files changed, 62 insertions(+), 5 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1399d301d47f..5cba90948a7e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -733,18 +733,23 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk)
static bool mptcp_do_flush_join_list(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
+ bool ret = false;
if (likely(list_empty(&msk->join_list)))
return false;
spin_lock_bh(&msk->join_list_lock);
- list_for_each_entry(subflow, &msk->join_list, node)
- mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow));
+ list_for_each_entry(subflow, &msk->join_list, node) {
+ u32 sseq = READ_ONCE(subflow->setsockopt_seq);
+ mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow));
+ if (READ_ONCE(msk->setsockopt_seq) != sseq)
+ ret = true;
+ }
list_splice_tail_init(&msk->join_list, &msk->conn_list);
spin_unlock_bh(&msk->join_list_lock);
- return true;
+ return ret;
}
void __mptcp_flush_join_list(struct mptcp_sock *msk)
@@ -2718,6 +2723,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
msk->snd_nxt = msk->write_seq;
msk->snd_una = msk->write_seq;
msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
+ msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
if (mp_opt->mp_capable) {
msk->can_ack = true;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 0186aad3108a..df269c26f145 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -256,6 +256,8 @@ struct mptcp_sock {
u64 time; /* start time of measurement window */
u64 rtt_us; /* last maximum rtt of subflows */
} rcvq_space;
+
+ u32 setsockopt_seq;
};
#define mptcp_lock_sock(___sk, cb) do { \
@@ -414,6 +416,8 @@ struct mptcp_subflow_context {
long delegated_status;
struct list_head delegated_node; /* link into delegated_action, protected by local BH */
+ u32 setsockopt_seq;
+
struct sock *tcp_sock; /* tcp sk backpointer */
struct sock *conn; /* parent mptcp_sock */
const struct inet_connection_sock_af_ops *icsk_af_ops;
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 4fdc0ad6acf7..27b49543fc58 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -24,6 +24,27 @@ static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk)
return msk->first;
}
+static u32 sockopt_seq_reset(const struct sock *sk)
+{
+ sock_owned_by_me(sk);
+
+ /* Highbits contain state. Allows to distinguish sockopt_seq
+ * of listener and established:
+ * s0 = new_listener()
+ * sockopt(s0) - seq is 1
+ * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0)
+ * sockopt(s0) - seq increments to 2 on s0
+ * sockopt(s1) // seq increments to 2 on s1 (different option)
+ * new ssk completes join, inherits options from s0 // seq 2
+ * Needs sync from mptcp join logic, but ssk->seq == msk->seq
+ *
+ * Set High order bits to sk_state so ssk->seq == msk->seq test
+ * will fail.
+ */
+
+ return (u32)sk->sk_state << 24u;
+}
+
static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -350,22 +371,44 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname,
return -EOPNOTSUPP;
}
+static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk)
+{
+}
+
void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk)
{
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+
msk_owned_by_me(msk);
+
+ if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) {
+ __mptcp_sockopt_sync(msk, ssk);
+
+ subflow->setsockopt_seq = msk->setsockopt_seq;
+ }
}
void mptcp_sockopt_sync_all(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
+ struct sock *sk = (struct sock *)msk;
+ u32 seq;
- msk_owned_by_me(msk);
+ seq = sockopt_seq_reset(sk);
mptcp_for_each_subflow(msk, subflow) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+ u32 sseq = READ_ONCE(subflow->setsockopt_seq);
- mptcp_sockopt_sync(msk, ssk);
+ if (sseq != msk->setsockopt_seq) {
+ __mptcp_sockopt_sync(msk, ssk);
+ WRITE_ONCE(subflow->setsockopt_seq, seq);
+ } else if (sseq != seq) {
+ WRITE_ONCE(subflow->setsockopt_seq, seq);
+ }
cond_resched();
}
+
+ msk->setsockopt_seq = seq;
}
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 350c51c6bf9d..c3da84576b3c 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -679,6 +679,9 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
goto out;
}
+ /* ssk inherits options of listener sk */
+ ctx->setsockopt_seq = listener->setsockopt_seq;
+
if (ctx->mp_capable) {
/* this can't race with mptcp_close(), as the msk is
* not yet exposted to user-space
@@ -694,6 +697,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
* created mptcp socket
*/
new_msk->sk_destruct = mptcp_sock_destruct;
+ mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq;
mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1);
mptcp_token_accept(subflow_req, mptcp_sk(new_msk));
ctx->conn = new_msk;
--
2.31.1
Powered by blists - more mailing lists