From f870fa0b5768842cb4690c1c11f19f28b731ae6d Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Tue, 21 Jan 2020 16:56:15 -0800 Subject: [PATCH] mptcp: Add MPTCP socket stubs Implements the infrastructure for MPTCP sockets. MPTCP sockets open one in-kernel TCP socket per subflow. These subflow sockets are only managed by the MPTCP socket that owns them and are not visible from userspace. This commit allows a userspace program to open an MPTCP socket with: sock = socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP); The resulting socket is simply a wrapper around a single regular TCP socket, without any of the MPTCP protocol implemented over the wire. Co-developed-by: Florian Westphal Signed-off-by: Florian Westphal Co-developed-by: Peter Krystad Signed-off-by: Peter Krystad Co-developed-by: Matthieu Baerts Signed-off-by: Matthieu Baerts Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Christoph Paasch Signed-off-by: David S. Miller --- MAINTAINERS | 1 + include/net/mptcp.h | 16 +++++ net/Kconfig | 1 + net/Makefile | 1 + net/ipv4/tcp.c | 2 + net/ipv6/tcp_ipv6.c | 7 +++ net/mptcp/Kconfig | 16 +++++ net/mptcp/Makefile | 4 ++ net/mptcp/protocol.c | 142 +++++++++++++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 22 +++++++ 10 files changed, 212 insertions(+) create mode 100644 net/mptcp/Kconfig create mode 100644 net/mptcp/Makefile create mode 100644 net/mptcp/protocol.c create mode 100644 net/mptcp/protocol.h diff --git a/MAINTAINERS b/MAINTAINERS index 702382b89c37..4be9c1b50183 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11583,6 +11583,7 @@ W: https://github.com/multipath-tcp/mptcp_net-next/wiki B: https://github.com/multipath-tcp/mptcp_net-next/issues S: Maintained F: include/net/mptcp.h +F: net/mptcp/ NETWORKING [TCP] M: Eric Dumazet diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 0573ae75c3db..98ba22379117 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -28,6 +28,8 @@ struct mptcp_ext { #ifdef CONFIG_MPTCP +void mptcp_init(void); + /* move the skb extension owership, with the assumption that 'to' is * newly allocated */ @@ -70,6 +72,10 @@ static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, #else +static inline void mptcp_init(void) +{ +} + static inline void mptcp_skb_ext_move(struct sk_buff *to, const struct sk_buff *from) { @@ -82,4 +88,14 @@ static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, } #endif /* CONFIG_MPTCP */ + +#if IS_ENABLED(CONFIG_MPTCP_IPV6) +int mptcpv6_init(void); +#elif IS_ENABLED(CONFIG_IPV6) +static inline int mptcpv6_init(void) +{ + return 0; +} +#endif + #endif /* __NET_MPTCP_H */ diff --git a/net/Kconfig b/net/Kconfig index 54916b7adb9b..b0937a700f01 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -91,6 +91,7 @@ if INET source "net/ipv4/Kconfig" source "net/ipv6/Kconfig" source "net/netlabel/Kconfig" +source "net/mptcp/Kconfig" endif # if INET diff --git a/net/Makefile b/net/Makefile index 848303d98d3d..07ea48160874 100644 --- a/net/Makefile +++ b/net/Makefile @@ -87,3 +87,4 @@ endif obj-$(CONFIG_QRTR) += qrtr/ obj-$(CONFIG_NET_NCSI) += ncsi/ obj-$(CONFIG_XDP_SOCKETS) += xdp/ +obj-$(CONFIG_MPTCP) += mptcp/ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 6711a97de3ce..7dfb78caedaf 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -271,6 +271,7 @@ #include #include #include +#include #include #include #include @@ -4021,4 +4022,5 @@ void __init tcp_init(void) tcp_metrics_init(); BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); tcp_tasklet_init(); + mptcp_init(); } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 5b5260103b65..60068ffde1d9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2163,9 +2163,16 @@ int __init tcpv6_init(void) ret = register_pernet_subsys(&tcpv6_net_ops); if (ret) goto out_tcpv6_protosw; + + ret = mptcpv6_init(); + if (ret) + goto out_tcpv6_pernet_subsys; + out: return ret; +out_tcpv6_pernet_subsys: + unregister_pernet_subsys(&tcpv6_net_ops); out_tcpv6_protosw: inet6_unregister_protosw(&tcpv6_protosw); out_tcpv6_protocol: diff --git a/net/mptcp/Kconfig b/net/mptcp/Kconfig new file mode 100644 index 000000000000..c1a99f07a4cd --- /dev/null +++ b/net/mptcp/Kconfig @@ -0,0 +1,16 @@ + +config MPTCP + bool "MPTCP: Multipath TCP" + depends on INET + select SKB_EXTENSIONS + help + Multipath TCP (MPTCP) connections send and receive data over multiple + subflows in order to utilize multiple network paths. Each subflow + uses the TCP protocol, and TCP options carry header information for + MPTCP. + +config MPTCP_IPV6 + bool "MPTCP: IPv6 support for Multipath TCP" + depends on MPTCP + select IPV6 + default y diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile new file mode 100644 index 000000000000..659129d1fcbf --- /dev/null +++ b/net/mptcp/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_MPTCP) += mptcp.o + +mptcp-y := protocol.o diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c new file mode 100644 index 000000000000..5e24e7cf7d70 --- /dev/null +++ b/net/mptcp/protocol.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2017 - 2019, Intel Corporation. + */ + +#define pr_fmt(fmt) "MPTCP: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "protocol.h" + +static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct socket *subflow = msk->subflow; + + if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) + return -EOPNOTSUPP; + + return sock_sendmsg(subflow, msg); +} + +static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, int *addr_len) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct socket *subflow = msk->subflow; + + if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) + return -EOPNOTSUPP; + + return sock_recvmsg(subflow, msg, flags); +} + +static int mptcp_init_sock(struct sock *sk) +{ + return 0; +} + +static void mptcp_close(struct sock *sk, long timeout) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + inet_sk_state_store(sk, TCP_CLOSE); + + if (msk->subflow) { + pr_debug("subflow=%p", msk->subflow->sk); + sock_release(msk->subflow); + } + + sock_orphan(sk); + sock_put(sk); +} + +static int mptcp_connect(struct sock *sk, struct sockaddr *saddr, int len) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + int err; + + saddr->sa_family = AF_INET; + + pr_debug("msk=%p, subflow=%p", msk, msk->subflow->sk); + + err = kernel_connect(msk->subflow, saddr, len, 0); + + sk->sk_state = TCP_ESTABLISHED; + + return err; +} + +static struct proto mptcp_prot = { + .name = "MPTCP", + .owner = THIS_MODULE, + .init = mptcp_init_sock, + .close = mptcp_close, + .accept = inet_csk_accept, + .connect = mptcp_connect, + .shutdown = tcp_shutdown, + .sendmsg = mptcp_sendmsg, + .recvmsg = mptcp_recvmsg, + .hash = inet_hash, + .unhash = inet_unhash, + .get_port = inet_csk_get_port, + .obj_size = sizeof(struct mptcp_sock), + .no_autobind = true, +}; + +static struct inet_protosw mptcp_protosw = { + .type = SOCK_STREAM, + .protocol = IPPROTO_MPTCP, + .prot = &mptcp_prot, + .ops = &inet_stream_ops, +}; + +void __init mptcp_init(void) +{ + if (proto_register(&mptcp_prot, 1) != 0) + panic("Failed to register MPTCP proto.\n"); + + inet_register_protosw(&mptcp_protosw); +} + +#if IS_ENABLED(CONFIG_MPTCP_IPV6) +static struct proto mptcp_v6_prot; + +static struct inet_protosw mptcp_v6_protosw = { + .type = SOCK_STREAM, + .protocol = IPPROTO_MPTCP, + .prot = &mptcp_v6_prot, + .ops = &inet6_stream_ops, + .flags = INET_PROTOSW_ICSK, +}; + +int mptcpv6_init(void) +{ + int err; + + mptcp_v6_prot = mptcp_prot; + strcpy(mptcp_v6_prot.name, "MPTCPv6"); + mptcp_v6_prot.slab = NULL; + mptcp_v6_prot.obj_size = sizeof(struct mptcp_sock) + + sizeof(struct ipv6_pinfo); + + err = proto_register(&mptcp_v6_prot, 1); + if (err) + return err; + + err = inet6_register_protosw(&mptcp_v6_protosw); + if (err) + proto_unregister(&mptcp_v6_prot); + + return err; +} +#endif diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h new file mode 100644 index 000000000000..ee04a01bffd3 --- /dev/null +++ b/net/mptcp/protocol.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Multipath TCP + * + * Copyright (c) 2017 - 2019, Intel Corporation. + */ + +#ifndef __MPTCP_PROTOCOL_H +#define __MPTCP_PROTOCOL_H + +/* MPTCP connection sock */ +struct mptcp_sock { + /* inet_connection_sock must be the first member */ + struct inet_connection_sock sk; + struct socket *subflow; /* outgoing connect/listener/!mp_capable */ +}; + +static inline struct mptcp_sock *mptcp_sk(const struct sock *sk) +{ + return (struct mptcp_sock *)sk; +} + +#endif /* __MPTCP_PROTOCOL_H */