mctp: Add base socket/protocol definitions

Add an empty socket implementation, plus initialisation/destruction
handlers.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index 8f9c77e97357a68f7b4e3186453b8efe9f5e9897..b3aeca6486e37ce2d96e9b30a20507a2b4697b20 100644 (file)
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -6,8 +6,171 @@
  * Copyright (c) 2021 Google
  */
 
+#include <linux/net.h>
+#include <linux/mctp.h>
 #include <linux/module.h>
+#include <linux/socket.h>
+
+#include <net/sock.h>
+
+struct mctp_sock {
+       struct sock     sk;
+};
+
+static int mctp_release(struct socket *sock)
+{
+       struct sock *sk = sock->sk;
+
+       if (sk) {
+               sock->sk = NULL;
+               sk->sk_prot->close(sk, 0);
+       }
+
+       return 0;
+}
+
+static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
+{
+       return 0;
+}
+
+static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+       return 0;
+}
+
+static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+                       int flags)
+{
+       return 0;
+}
+
+static int mctp_setsockopt(struct socket *sock, int level, int optname,
+                          sockptr_t optval, unsigned int optlen)
+{
+       return -EINVAL;
+}
+
+static int mctp_getsockopt(struct socket *sock, int level, int optname,
+                          char __user *optval, int __user *optlen)
+{
+       return -EINVAL;
+}
+
+static const struct proto_ops mctp_dgram_ops = {
+       .family         = PF_MCTP,
+       .release        = mctp_release,
+       .bind           = mctp_bind,
+       .connect        = sock_no_connect,
+       .socketpair     = sock_no_socketpair,
+       .accept         = sock_no_accept,
+       .getname        = sock_no_getname,
+       .poll           = datagram_poll,
+       .ioctl          = sock_no_ioctl,
+       .gettstamp      = sock_gettstamp,
+       .listen         = sock_no_listen,
+       .shutdown       = sock_no_shutdown,
+       .setsockopt     = mctp_setsockopt,
+       .getsockopt     = mctp_getsockopt,
+       .sendmsg        = mctp_sendmsg,
+       .recvmsg        = mctp_recvmsg,
+       .mmap           = sock_no_mmap,
+       .sendpage       = sock_no_sendpage,
+};
+
+static void mctp_sk_close(struct sock *sk, long timeout)
+{
+       sk_common_release(sk);
+}
+
+static struct proto mctp_proto = {
+       .name           = "MCTP",
+       .owner          = THIS_MODULE,
+       .obj_size       = sizeof(struct mctp_sock),
+       .close          = mctp_sk_close,
+};
+
+static int mctp_pf_create(struct net *net, struct socket *sock,
+                         int protocol, int kern)
+{
+       const struct proto_ops *ops;
+       struct proto *proto;
+       struct sock *sk;
+       int rc;
+
+       if (protocol)
+               return -EPROTONOSUPPORT;
+
+       /* only datagram sockets are supported */
+       if (sock->type != SOCK_DGRAM)
+               return -ESOCKTNOSUPPORT;
+
+       proto = &mctp_proto;
+       ops = &mctp_dgram_ops;
+
+       sock->state = SS_UNCONNECTED;
+       sock->ops = ops;
+
+       sk = sk_alloc(net, PF_MCTP, GFP_KERNEL, proto, kern);
+       if (!sk)
+               return -ENOMEM;
+
+       sock_init_data(sock, sk);
+
+       rc = 0;
+       if (sk->sk_prot->init)
+               rc = sk->sk_prot->init(sk);
+
+       if (rc)
+               goto err_sk_put;
+
+       return 0;
+
+err_sk_put:
+       sock_orphan(sk);
+       sock_put(sk);
+       return rc;
+}
+
+static struct net_proto_family mctp_pf = {
+       .family = PF_MCTP,
+       .create = mctp_pf_create,
+       .owner = THIS_MODULE,
+};
+
+static __init int mctp_init(void)
+{
+       int rc;
+
+       pr_info("mctp: management component transport protocol core\n");
+
+       rc = sock_register(&mctp_pf);
+       if (rc)
+               return rc;
+
+       rc = proto_register(&mctp_proto, 0);
+       if (rc)
+               goto err_unreg_sock;
+
+       return 0;
+
+err_unreg_sock:
+       sock_unregister(PF_MCTP);
+
+       return rc;
+}
+
+static __exit void mctp_exit(void)
+{
+       proto_unregister(&mctp_proto);
+       sock_unregister(PF_MCTP);
+}
+
+module_init(mctp_init);
+module_exit(mctp_exit);
 
 MODULE_DESCRIPTION("MCTP core");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");
+
+MODULE_ALIAS_NETPROTO(PF_MCTP);