mptcp: Create SUBFLOW socket for incoming connections (cf7da0d6) · Commits · 戴 / test

net/mptcp/protocol.c

+231 −5

Original line number	Diff line number	Diff line
		@@ -14,6 +14,9 @@
		#include <net/inet_hashtables.h>
		#include <net/protocol.h>
		#include <net/tcp.h>
		#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		#include <net/transp_v6.h>
		#endif
		#include <net/mptcp.h>
		#include "protocol.h"

		@@ -212,6 +215,90 @@ static void mptcp_close(struct sock *sk, long timeout)
		sk_common_release(sk);
		}

		static void mptcp_copy_inaddrs(struct sock msk, const struct sock ssk)
		{
		#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
		struct ipv6_pinfo *msk6 = inet6_sk(msk);

		msk->sk_v6_daddr = ssk->sk_v6_daddr;
		msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;

		if (msk6 && ssk6) {
		msk6->saddr = ssk6->saddr;
		msk6->flow_label = ssk6->flow_label;
		}
		#endif

		inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
		inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
		inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
		inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
		inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
		inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr;
		}

		static struct sock mptcp_accept(struct sock sk, int flags, int *err,
		bool kern)
		{
		struct mptcp_sock *msk = mptcp_sk(sk);
		struct socket *listener;
		struct sock *newsk;

		listener = __mptcp_nmpc_socket(msk);
		if (WARN_ON_ONCE(!listener)) {
		*err = -EINVAL;
		return NULL;
		}

		pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
		newsk = inet_csk_accept(listener->sk, flags, err, kern);
		if (!newsk)
		return NULL;

		pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));

		if (sk_is_mptcp(newsk)) {
		struct mptcp_subflow_context *subflow;
		struct sock *new_mptcp_sock;
		struct sock *ssk = newsk;

		subflow = mptcp_subflow_ctx(newsk);
		lock_sock(sk);

		local_bh_disable();
		new_mptcp_sock = sk_clone_lock(sk, GFP_ATOMIC);
		if (!new_mptcp_sock) {
		*err = -ENOBUFS;
		local_bh_enable();
		release_sock(sk);
		tcp_close(newsk, 0);
		return NULL;
		}

		mptcp_init_sock(new_mptcp_sock);

		msk = mptcp_sk(new_mptcp_sock);
		msk->remote_key = subflow->remote_key;
		msk->local_key = subflow->local_key;
		msk->subflow = NULL;

		newsk = new_mptcp_sock;
		mptcp_copy_inaddrs(newsk, ssk);
		list_add(&subflow->node, &msk->conn_list);

		/* will be fully established at mptcp_stream_accept()
		* completion.
		*/
		inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV);
		bh_unlock_sock(new_mptcp_sock);
		local_bh_enable();
		release_sock(sk);
		}

		return newsk;
		}

		static int mptcp_get_port(struct sock *sk, unsigned short snum)
		{
		struct mptcp_sock *msk = mptcp_sk(sk);
		@@ -246,12 +333,21 @@ void mptcp_finish_connect(struct sock *ssk)
		WRITE_ONCE(msk->local_key, subflow->local_key);
		}

		static void mptcp_sock_graft(struct sock sk, struct socket parent)
		{
		write_lock_bh(&sk->sk_callback_lock);
		rcu_assign_pointer(sk->sk_wq, &parent->wq);
		sk_set_socket(sk, parent);
		sk->sk_uid = SOCK_INODE(parent)->i_uid;
		write_unlock_bh(&sk->sk_callback_lock);
		}

		static struct proto mptcp_prot = {
		.name = "MPTCP",
		.owner = THIS_MODULE,
		.init = mptcp_init_sock,
		.close = mptcp_close,
		.accept = inet_csk_accept,
		.accept = mptcp_accept,
		.shutdown = tcp_shutdown,
		.sendmsg = mptcp_sendmsg,
		.recvmsg = mptcp_recvmsg,
		@@ -266,10 +362,7 @@ static int mptcp_bind(struct socket sock, struct sockaddr uaddr, int addr_len)
		{
		struct mptcp_sock *msk = mptcp_sk(sock->sk);
		struct socket *ssock;
		int err = -ENOTSUPP;

		if (uaddr->sa_family != AF_INET) // @@ allow only IPv4 for now
		return err;
		int err;

		lock_sock(sock->sk);
		ssock = __mptcp_socket_create(msk, MPTCP_SAME_STATE);
		@@ -279,6 +372,8 @@ static int mptcp_bind(struct socket sock, struct sockaddr uaddr, int addr_len)
		}

		err = ssock->ops->bind(ssock, uaddr, addr_len);
		if (!err)
		mptcp_copy_inaddrs(sock->sk, ssock->sk);

		unlock:
		release_sock(sock->sk);
		@@ -299,14 +394,139 @@ static int mptcp_stream_connect(struct socket sock, struct sockaddr uaddr,
		goto unlock;
		}

		#ifdef CONFIG_TCP_MD5SIG
		/* no MPTCP if MD5SIG is enabled on this socket or we may run out of
		* TCP option space.
		*/
		if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
		mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0;
		#endif

		err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
		inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
		mptcp_copy_inaddrs(sock->sk, ssock->sk);

		unlock:
		release_sock(sock->sk);
		return err;
		}

		static int mptcp_v4_getname(struct socket sock, struct sockaddr uaddr,
		int peer)
		{
		if (sock->sk->sk_prot == &tcp_prot) {
		/* we are being invoked from __sys_accept4, after
		* mptcp_accept() has just accepted a non-mp-capable
		* flow: sk is a tcp_sk, not an mptcp one.
		*
		* Hand the socket over to tcp so all further socket ops
		* bypass mptcp.
		*/
		sock->ops = &inet_stream_ops;
		}

		return inet_getname(sock, uaddr, peer);
		}

		#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		static int mptcp_v6_getname(struct socket sock, struct sockaddr uaddr,
		int peer)
		{
		if (sock->sk->sk_prot == &tcpv6_prot) {
		/* we are being invoked from __sys_accept4 after
		* mptcp_accept() has accepted a non-mp-capable
		* subflow: sk is a tcp_sk, not mptcp.
		*
		* Hand the socket over to tcp so all further
		* socket ops bypass mptcp.
		*/
		sock->ops = &inet6_stream_ops;
		}

		return inet6_getname(sock, uaddr, peer);
		}
		#endif

		static int mptcp_listen(struct socket *sock, int backlog)
		{
		struct mptcp_sock *msk = mptcp_sk(sock->sk);
		struct socket *ssock;
		int err;

		pr_debug("msk=%p", msk);

		lock_sock(sock->sk);
		ssock = __mptcp_socket_create(msk, TCP_LISTEN);
		if (IS_ERR(ssock)) {
		err = PTR_ERR(ssock);
		goto unlock;
		}

		err = ssock->ops->listen(ssock, backlog);
		inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
		if (!err)
		mptcp_copy_inaddrs(sock->sk, ssock->sk);

		unlock:
		release_sock(sock->sk);
		return err;
		}

		static bool is_tcp_proto(const struct proto *p)
		{
		#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		return p == &tcp_prot \|\| p == &tcpv6_prot;
		#else
		return p == &tcp_prot;
		#endif
		}

		static int mptcp_stream_accept(struct socket sock, struct socket newsock,
		int flags, bool kern)
		{
		struct mptcp_sock *msk = mptcp_sk(sock->sk);
		struct socket *ssock;
		int err;

		pr_debug("msk=%p", msk);

		lock_sock(sock->sk);
		if (sock->sk->sk_state != TCP_LISTEN)
		goto unlock_fail;

		ssock = __mptcp_nmpc_socket(msk);
		if (!ssock)
		goto unlock_fail;

		sock_hold(ssock->sk);
		release_sock(sock->sk);

		err = ssock->ops->accept(sock, newsock, flags, kern);
		if (err == 0 && !is_tcp_proto(newsock->sk->sk_prot)) {
		struct mptcp_sock *msk = mptcp_sk(newsock->sk);
		struct mptcp_subflow_context *subflow;

		/* set ssk->sk_socket of accept()ed flows to mptcp socket.
		* This is needed so NOSPACE flag can be set from tcp stack.
		*/
		list_for_each_entry(subflow, &msk->conn_list, node) {
		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);

		if (!ssk->sk_socket)
		mptcp_sock_graft(ssk, newsock);
		}

		inet_sk_state_store(newsock->sk, TCP_ESTABLISHED);
		}

		sock_put(ssock->sk);
		return err;

		unlock_fail:
		release_sock(sock->sk);
		return -EINVAL;
		}

		static __poll_t mptcp_poll(struct file file, struct socket sock,
		struct poll_table_struct *wait)
		{
		@@ -332,6 +552,9 @@ void __init mptcp_init(void)
		mptcp_stream_ops.bind = mptcp_bind;
		mptcp_stream_ops.connect = mptcp_stream_connect;
		mptcp_stream_ops.poll = mptcp_poll;
		mptcp_stream_ops.accept = mptcp_stream_accept;
		mptcp_stream_ops.getname = mptcp_v4_getname;
		mptcp_stream_ops.listen = mptcp_listen;

		mptcp_subflow_init();

		@@ -371,6 +594,9 @@ int mptcpv6_init(void)
		mptcp_v6_stream_ops.bind = mptcp_bind;
		mptcp_v6_stream_ops.connect = mptcp_stream_connect;
		mptcp_v6_stream_ops.poll = mptcp_poll;
		mptcp_v6_stream_ops.accept = mptcp_stream_accept;
		mptcp_v6_stream_ops.getname = mptcp_v6_getname;
		mptcp_v6_stream_ops.listen = mptcp_listen;

		err = inet6_register_protosw(&mptcp_v6_protosw);
		if (err)

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