net/mptcp/protocol.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2017 - 2019, Intel Corporation.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/netdevice.h>
  12 #include <net/sock.h>
  13 #include <net/inet_common.h>
  14 #include <net/inet_hashtables.h>
  15 #include <net/protocol.h>
  16 #include <net/tcp.h>
  17 #include <net/mptcp.h>
  18 #include "protocol.h"
  19
  20 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
  21 {
  22         struct mptcp_sock *msk = mptcp_sk(sk);
  23         struct socket *subflow = msk->subflow;
  24
  25         if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
  26                 return -EOPNOTSUPP;
  27
  28         return sock_sendmsg(subflow, msg);
  29 }
  30
  31 static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
  32                          int nonblock, int flags, int *addr_len)
  33 {
  34         struct mptcp_sock *msk = mptcp_sk(sk);
  35         struct socket *subflow = msk->subflow;
  36
  37         if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT))
  38                 return -EOPNOTSUPP;
  39
  40         return sock_recvmsg(subflow, msg, flags);
  41 }
  42
  43 static int mptcp_init_sock(struct sock *sk)
  44 {
  45         return 0;
  46 }
  47
  48 static void mptcp_close(struct sock *sk, long timeout)
  49 {
  50         struct mptcp_sock *msk = mptcp_sk(sk);
  51
  52         inet_sk_state_store(sk, TCP_CLOSE);
  53
  54         if (msk->subflow) {
  55                 pr_debug("subflow=%p", msk->subflow->sk);
  56                 sock_release(msk->subflow);
  57         }
  58
  59         sock_orphan(sk);
  60         sock_put(sk);
  61 }
  62
  63 static int mptcp_connect(struct sock *sk, struct sockaddr *saddr, int len)
  64 {
  65         struct mptcp_sock *msk = mptcp_sk(sk);
  66         int err;
  67
  68         saddr->sa_family = AF_INET;
  69
  70         pr_debug("msk=%p, subflow=%p", msk, msk->subflow->sk);
  71
  72         err = kernel_connect(msk->subflow, saddr, len, 0);
  73
  74         sk->sk_state = TCP_ESTABLISHED;
  75
  76         return err;
  77 }
  78
  79 static struct proto mptcp_prot = {
  80         .name           = "MPTCP",
  81         .owner          = THIS_MODULE,
  82         .init           = mptcp_init_sock,
  83         .close          = mptcp_close,
  84         .accept         = inet_csk_accept,
  85         .connect        = mptcp_connect,
  86         .shutdown       = tcp_shutdown,
  87         .sendmsg        = mptcp_sendmsg,
  88         .recvmsg        = mptcp_recvmsg,
  89         .hash           = inet_hash,
  90         .unhash         = inet_unhash,
  91         .get_port       = inet_csk_get_port,
  92         .obj_size       = sizeof(struct mptcp_sock),
  93         .no_autobind    = true,
  94 };
  95
  96 static struct inet_protosw mptcp_protosw = {
  97         .type           = SOCK_STREAM,
  98         .protocol       = IPPROTO_MPTCP,
  99         .prot           = &mptcp_prot,
 100         .ops            = &inet_stream_ops,
 101 };
 102
 103 void __init mptcp_init(void)
 104 {
 105         if (proto_register(&mptcp_prot, 1) != 0)
 106                 panic("Failed to register MPTCP proto.\n");
 107
 108         inet_register_protosw(&mptcp_protosw);
 109 }
 110
 111 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 112 static struct proto mptcp_v6_prot;
 113
 114 static struct inet_protosw mptcp_v6_protosw = {
 115         .type           = SOCK_STREAM,
 116         .protocol       = IPPROTO_MPTCP,
 117         .prot           = &mptcp_v6_prot,
 118         .ops            = &inet6_stream_ops,
 119         .flags          = INET_PROTOSW_ICSK,
 120 };
 121
 122 int mptcpv6_init(void)
 123 {
 124         int err;
 125
 126         mptcp_v6_prot = mptcp_prot;
 127         strcpy(mptcp_v6_prot.name, "MPTCPv6");
 128         mptcp_v6_prot.slab = NULL;
 129         mptcp_v6_prot.obj_size = sizeof(struct mptcp_sock) +
 130                                  sizeof(struct ipv6_pinfo);
 131
 132         err = proto_register(&mptcp_v6_prot, 1);
 133         if (err)
 134                 return err;
 135
 136         err = inet6_register_protosw(&mptcp_v6_protosw);
 137         if (err)
 138                 proto_unregister(&mptcp_v6_prot);
 139
 140         return err;
 141 }
 142 #endif