blob: 77137a8627d06745e770361a68353d122ea482f7 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Management Component Transport Protocol (MCTP)
*
* Copyright (c) 2021 Code Construct
* Copyright (c) 2021 Google
*/
#include <linux/if_arp.h>
#include <linux/net.h>
#include <linux/mctp.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <net/mctp.h>
#include <net/mctpdevice.h>
#include <net/sock.h>
/* socket implementation */
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;
}
/* Generic sockaddr checks, padding checks only so far */
static bool mctp_sockaddr_is_ok(const struct sockaddr_mctp *addr)
{
return !addr->__smctp_pad0 && !addr->__smctp_pad1;
}
static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
{
struct sock *sk = sock->sk;
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct sockaddr_mctp *smctp;
int rc;
if (addrlen < sizeof(*smctp))
return -EINVAL;
if (addr->sa_family != AF_MCTP)
return -EAFNOSUPPORT;
if (!capable(CAP_NET_BIND_SERVICE))
return -EACCES;
/* it's a valid sockaddr for MCTP, cast and do protocol checks */
smctp = (struct sockaddr_mctp *)addr;
if (!mctp_sockaddr_is_ok(smctp))
return -EINVAL;
lock_sock(sk);
/* TODO: allow rebind */
if (sk_hashed(sk)) {
rc = -EADDRINUSE;
goto out_release;
}
msk->bind_net = smctp->smctp_network;
msk->bind_addr = smctp->smctp_addr.s_addr;
msk->bind_type = smctp->smctp_type & 0x7f; /* ignore the IC bit */
rc = sk->sk_prot->hash(sk);
out_release:
release_sock(sk);
return rc;
}
static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
const int hlen = MCTP_HEADER_MAXLEN + sizeof(struct mctp_hdr);
int rc, addrlen = msg->msg_namelen;
struct sock *sk = sock->sk;
struct mctp_skb_cb *cb;
struct mctp_route *rt;
struct sk_buff *skb;
if (addr) {
if (addrlen < sizeof(struct sockaddr_mctp))
return -EINVAL;
if (addr->smctp_family != AF_MCTP)
return -EINVAL;
if (!mctp_sockaddr_is_ok(addr))
return -EINVAL;
if (addr->smctp_tag & ~(MCTP_TAG_MASK | MCTP_TAG_OWNER))
return -EINVAL;
} else {
/* TODO: connect()ed sockets */
return -EDESTADDRREQ;
}
if (!capable(CAP_NET_RAW))
return -EACCES;
if (addr->smctp_network == MCTP_NET_ANY)
addr->smctp_network = mctp_default_net(sock_net(sk));
rt = mctp_route_lookup(sock_net(sk), addr->smctp_network,
addr->smctp_addr.s_addr);
if (!rt)
return -EHOSTUNREACH;
skb = sock_alloc_send_skb(sk, hlen + 1 + len,
msg->msg_flags & MSG_DONTWAIT, &rc);
if (!skb)
return rc;
skb_reserve(skb, hlen);
/* set type as fist byte in payload */
*(u8 *)skb_put(skb, 1) = addr->smctp_type;
rc = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
if (rc < 0) {
kfree_skb(skb);
return rc;
}
/* set up cb */
cb = __mctp_cb(skb);
cb->net = addr->smctp_network;
rc = mctp_local_output(sk, rt, skb, addr->smctp_addr.s_addr,
addr->smctp_tag);
return rc ? : len;
}
static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
struct sock *sk = sock->sk;
struct sk_buff *skb;
size_t msglen;
u8 type;
int rc;
if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK))
return -EOPNOTSUPP;
skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &rc);
if (!skb)
return rc;
if (!skb->len) {
rc = 0;
goto out_free;
}
/* extract message type, remove from data */
type = *((u8 *)skb->data);
msglen = skb->len - 1;
if (len < msglen)
msg->msg_flags |= MSG_TRUNC;
else
len = msglen;
rc = skb_copy_datagram_msg(skb, 1, msg, len);
if (rc < 0)
goto out_free;
sock_recv_ts_and_drops(msg, sk, skb);
if (addr) {
struct mctp_skb_cb *cb = mctp_cb(skb);
/* TODO: expand mctp_skb_cb for header fields? */
struct mctp_hdr *hdr = mctp_hdr(skb);
addr = msg->msg_name;
addr->smctp_family = AF_MCTP;
addr->__smctp_pad0 = 0;
addr->smctp_network = cb->net;
addr->smctp_addr.s_addr = hdr->src;
addr->smctp_type = type;
addr->smctp_tag = hdr->flags_seq_tag &
(MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
addr->__smctp_pad1 = 0;
msg->msg_namelen = sizeof(*addr);
}
rc = len;
if (flags & MSG_TRUNC)
rc = msglen;
out_free:
skb_free_datagram(sk, skb);
return rc;
}
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 int mctp_sk_init(struct sock *sk)
{
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
INIT_HLIST_HEAD(&msk->keys);
return 0;
}
static void mctp_sk_close(struct sock *sk, long timeout)
{
sk_common_release(sk);
}
static int mctp_sk_hash(struct sock *sk)
{
struct net *net = sock_net(sk);
mutex_lock(&net->mctp.bind_lock);
sk_add_node_rcu(sk, &net->mctp.binds);
mutex_unlock(&net->mctp.bind_lock);
return 0;
}
static void mctp_sk_unhash(struct sock *sk)
{
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct net *net = sock_net(sk);
struct mctp_sk_key *key;
struct hlist_node *tmp;
unsigned long flags;
/* remove from any type-based binds */
mutex_lock(&net->mctp.bind_lock);
sk_del_node_init_rcu(sk);
mutex_unlock(&net->mctp.bind_lock);
/* remove tag allocations */
spin_lock_irqsave(&net->mctp.keys_lock, flags);
hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
hlist_del_rcu(&key->sklist);
hlist_del_rcu(&key->hlist);
spin_lock(&key->reasm_lock);
if (key->reasm_head)
kfree_skb(key->reasm_head);
key->reasm_head = NULL;
key->reasm_dead = true;
spin_unlock(&key->reasm_lock);
kfree_rcu(key, rcu);
}
sock_set_flag(sk, SOCK_DEAD);
spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
synchronize_rcu();
}
static void mctp_sk_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_receive_queue);
}
static struct proto mctp_proto = {
.name = "MCTP",
.owner = THIS_MODULE,
.obj_size = sizeof(struct mctp_sock),
.init = mctp_sk_init,
.close = mctp_sk_close,
.hash = mctp_sk_hash,
.unhash = mctp_sk_unhash,
};
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);
sk->sk_destruct = mctp_sk_destruct;
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;
/* ensure our uapi tag definitions match the header format */
BUILD_BUG_ON(MCTP_TAG_OWNER != MCTP_HDR_FLAG_TO);
BUILD_BUG_ON(MCTP_TAG_MASK != MCTP_HDR_TAG_MASK);
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;
rc = mctp_routes_init();
if (rc)
goto err_unreg_proto;
rc = mctp_neigh_init();
if (rc)
goto err_unreg_routes;
mctp_device_init();
return 0;
err_unreg_routes:
mctp_routes_exit();
err_unreg_proto:
proto_unregister(&mctp_proto);
err_unreg_sock:
sock_unregister(PF_MCTP);
return rc;
}
static __exit void mctp_exit(void)
{
mctp_device_exit();
mctp_neigh_exit();
mctp_routes_exit();
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);