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Diffstat (limited to 'net/mptcp/protocol.c')
-rw-r--r--net/mptcp/protocol.c107
1 files changed, 69 insertions, 38 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b998e9df53ce..08dc53f56bc2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -49,18 +49,6 @@ static void __mptcp_check_send_data_fin(struct sock *sk);
DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
static struct net_device mptcp_napi_dev;
-/* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
- * completed yet or has failed, return the subflow socket.
- * Otherwise return NULL.
- */
-struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk)
-{
- if (!msk->subflow || READ_ONCE(msk->can_ack))
- return NULL;
-
- return msk->subflow;
-}
-
/* Returns end sequence number of the receiver's advertised window */
static u64 mptcp_wnd_end(const struct mptcp_sock *msk)
{
@@ -116,6 +104,31 @@ static int __mptcp_socket_create(struct mptcp_sock *msk)
return 0;
}
+/* If the MPC handshake is not started, returns the first subflow,
+ * eventually allocating it.
+ */
+struct socket *__mptcp_nmpc_socket(struct mptcp_sock *msk)
+{
+ struct sock *sk = (struct sock *)msk;
+ int ret;
+
+ if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
+ return ERR_PTR(-EINVAL);
+
+ if (!msk->subflow) {
+ if (msk->first)
+ return ERR_PTR(-EINVAL);
+
+ ret = __mptcp_socket_create(msk);
+ if (ret)
+ return ERR_PTR(ret);
+
+ mptcp_sockopt_sync(msk, msk->first);
+ }
+
+ return msk->subflow;
+}
+
static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
{
sk_drops_add(sk, skb);
@@ -459,7 +472,7 @@ static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
return false;
}
-static void mptcp_set_datafin_timeout(const struct sock *sk)
+static void mptcp_set_datafin_timeout(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
u32 retransmits;
@@ -1662,13 +1675,31 @@ static void mptcp_set_nospace(struct sock *sk)
static int mptcp_disconnect(struct sock *sk, int flags);
-static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msghdr *msg,
+static int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
size_t len, int *copied_syn)
{
unsigned int saved_flags = msg->msg_flags;
struct mptcp_sock *msk = mptcp_sk(sk);
+ struct socket *ssock;
+ struct sock *ssk;
int ret;
+ /* on flags based fastopen the mptcp is supposed to create the
+ * first subflow right now. Otherwise we are in the defer_connect
+ * path, and the first subflow must be already present.
+ * Since the defer_connect flag is cleared after the first succsful
+ * fastopen attempt, no need to check for additional subflow status.
+ */
+ if (msg->msg_flags & MSG_FASTOPEN) {
+ ssock = __mptcp_nmpc_socket(msk);
+ if (IS_ERR(ssock))
+ return PTR_ERR(ssock);
+ }
+ if (!msk->first)
+ return -EINVAL;
+
+ ssk = msk->first;
+
lock_sock(ssk);
msg->msg_flags |= MSG_DONTWAIT;
msk->connect_flags = O_NONBLOCK;
@@ -1691,6 +1722,7 @@ static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msgh
} else if (ret && ret != -EINPROGRESS) {
mptcp_disconnect(sk, 0);
}
+ inet_sk(sk)->defer_connect = 0;
return ret;
}
@@ -1699,7 +1731,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct mptcp_sock *msk = mptcp_sk(sk);
struct page_frag *pfrag;
- struct socket *ssock;
size_t copied = 0;
int ret = 0;
long timeo;
@@ -1709,12 +1740,10 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
lock_sock(sk);
- ssock = __mptcp_nmpc_socket(msk);
- if (unlikely(ssock && (inet_sk(ssock->sk)->defer_connect ||
- msg->msg_flags & MSG_FASTOPEN))) {
+ if (unlikely(inet_sk(sk)->defer_connect || msg->msg_flags & MSG_FASTOPEN)) {
int copied_syn = 0;
- ret = mptcp_sendmsg_fastopen(sk, ssock->sk, msg, len, &copied_syn);
+ ret = mptcp_sendmsg_fastopen(sk, msg, len, &copied_syn);
copied += copied_syn;
if (ret == -EINPROGRESS && copied_syn > 0)
goto out;
@@ -2486,15 +2515,15 @@ static void mptcp_check_fastclose(struct mptcp_sock *msk)
/* Mirror the tcp_reset() error propagation */
switch (sk->sk_state) {
case TCP_SYN_SENT:
- sk->sk_err = ECONNREFUSED;
+ WRITE_ONCE(sk->sk_err, ECONNREFUSED);
break;
case TCP_CLOSE_WAIT:
- sk->sk_err = EPIPE;
+ WRITE_ONCE(sk->sk_err, EPIPE);
break;
case TCP_CLOSE:
return;
default:
- sk->sk_err = ECONNRESET;
+ WRITE_ONCE(sk->sk_err, ECONNRESET);
}
inet_sk_state_store(sk, TCP_CLOSE);
@@ -2734,10 +2763,6 @@ static int mptcp_init_sock(struct sock *sk)
if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net))
return -ENOMEM;
- ret = __mptcp_socket_create(mptcp_sk(sk));
- if (ret)
- return ret;
-
set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
/* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will
@@ -2942,10 +2967,13 @@ bool __mptcp_close(struct sock *sk, long timeout)
goto cleanup;
}
- if (mptcp_check_readable(msk)) {
- /* the msk has read data, do the MPTCP equivalent of TCP reset */
+ if (mptcp_check_readable(msk) || timeout < 0) {
+ /* If the msk has read data, or the caller explicitly ask it,
+ * do the MPTCP equivalent of TCP reset, aka MPTCP fastclose
+ */
inet_sk_state_store(sk, TCP_CLOSE);
mptcp_do_fastclose(sk);
+ timeout = 0;
} else if (mptcp_close_state(sk)) {
__mptcp_wr_shutdown(sk);
}
@@ -3157,7 +3185,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
struct socket *listener;
struct sock *newsk;
- listener = __mptcp_nmpc_socket(msk);
+ listener = msk->subflow;
if (WARN_ON_ONCE(!listener)) {
*err = -EINVAL;
return NULL;
@@ -3377,7 +3405,7 @@ static int mptcp_get_port(struct sock *sk, unsigned short snum)
struct mptcp_sock *msk = mptcp_sk(sk);
struct socket *ssock;
- ssock = __mptcp_nmpc_socket(msk);
+ ssock = msk->subflow;
pr_debug("msk=%p, subflow=%p", msk, ssock);
if (WARN_ON_ONCE(!ssock))
return -EINVAL;
@@ -3565,8 +3593,8 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
int err = -EINVAL;
ssock = __mptcp_nmpc_socket(msk);
- if (!ssock)
- return -EINVAL;
+ if (IS_ERR(ssock))
+ return PTR_ERR(ssock);
mptcp_token_destroy(msk);
inet_sk_state_store(sk, TCP_SYN_SENT);
@@ -3654,8 +3682,8 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
lock_sock(sock->sk);
ssock = __mptcp_nmpc_socket(msk);
- if (!ssock) {
- err = -EINVAL;
+ if (IS_ERR(ssock)) {
+ err = PTR_ERR(ssock);
goto unlock;
}
@@ -3691,8 +3719,8 @@ static int mptcp_listen(struct socket *sock, int backlog)
lock_sock(sk);
ssock = __mptcp_nmpc_socket(msk);
- if (!ssock) {
- err = -EINVAL;
+ if (IS_ERR(ssock)) {
+ err = PTR_ERR(ssock);
goto unlock;
}
@@ -3723,7 +3751,10 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
pr_debug("msk=%p", msk);
- ssock = __mptcp_nmpc_socket(msk);
+ /* buggy applications can call accept on socket states other then LISTEN
+ * but no need to allocate the first subflow just to error out.
+ */
+ ssock = msk->subflow;
if (!ssock)
return -EINVAL;
@@ -3817,7 +3848,7 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock,
/* This barrier is coupled with smp_wmb() in __mptcp_error_report() */
smp_rmb();
- if (sk->sk_err)
+ if (READ_ONCE(sk->sk_err))
mask |= EPOLLERR;
return mask;
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-07 19:55:46 +0300