blob: fc9e728b6333a1f126d8ac615e28fb66028217bc [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/compat.h>
#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>
#define CREATE_TRACE_POINTS
#include <trace/events/mctp.h>
/* socket implementation */
static void mctp_sk_expire_keys(struct timer_list *timer);
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 bool mctp_sockaddr_ext_is_ok(const struct sockaddr_mctp_ext *addr)
{
return !addr->__smctp_pad0[0] &&
!addr->__smctp_pad0[1] &&
!addr->__smctp_pad0[2];
}
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);
int rc, addrlen = msg->msg_namelen;
struct sock *sk = sock->sk;
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct mctp_skb_cb *cb;
struct mctp_route *rt;
struct sk_buff *skb = NULL;
int hlen;
if (addr) {
const u8 tagbits = MCTP_TAG_MASK | MCTP_TAG_OWNER |
MCTP_TAG_PREALLOC;
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 & ~tagbits)
return -EINVAL;
/* can't preallocate a non-owned tag */
if (addr->smctp_tag & MCTP_TAG_PREALLOC &&
!(addr->smctp_tag & 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));
/* direct addressing */
if (msk->addr_ext && addrlen >= sizeof(struct sockaddr_mctp_ext)) {
DECLARE_SOCKADDR(struct sockaddr_mctp_ext *,
extaddr, msg->msg_name);
struct net_device *dev;
rc = -EINVAL;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), extaddr->smctp_ifindex);
/* check for correct halen */
if (dev && extaddr->smctp_halen == dev->addr_len) {
hlen = LL_RESERVED_SPACE(dev) + sizeof(struct mctp_hdr);
rc = 0;
}
rcu_read_unlock();
if (rc)
goto err_free;
rt = NULL;
} else {
rt = mctp_route_lookup(sock_net(sk), addr->smctp_network,
addr->smctp_addr.s_addr);
if (!rt) {
rc = -EHOSTUNREACH;
goto err_free;
}
hlen = LL_RESERVED_SPACE(rt->dev->dev) + sizeof(struct mctp_hdr);
}
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)
goto err_free;
/* set up cb */
cb = __mctp_cb(skb);
cb->net = addr->smctp_network;
if (!rt) {
/* fill extended address in cb */
DECLARE_SOCKADDR(struct sockaddr_mctp_ext *,
extaddr, msg->msg_name);
if (!mctp_sockaddr_ext_is_ok(extaddr) ||
extaddr->smctp_halen > sizeof(cb->haddr)) {
rc = -EINVAL;
goto err_free;
}
cb->ifindex = extaddr->smctp_ifindex;
/* smctp_halen is checked above */
cb->halen = extaddr->smctp_halen;
memcpy(cb->haddr, extaddr->smctp_haddr, cb->halen);
}
rc = mctp_local_output(sk, rt, skb, addr->smctp_addr.s_addr,
addr->smctp_tag);
return rc ? : len;
err_free:
kfree_skb(skb);
return rc;
}
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 mctp_sock *msk = container_of(sk, struct mctp_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, &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_cmsgs(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);
if (msk->addr_ext) {
DECLARE_SOCKADDR(struct sockaddr_mctp_ext *, ae,
msg->msg_name);
msg->msg_namelen = sizeof(*ae);
ae->smctp_ifindex = cb->ifindex;
ae->smctp_halen = cb->halen;
memset(ae->__smctp_pad0, 0x0, sizeof(ae->__smctp_pad0));
memset(ae->smctp_haddr, 0x0, sizeof(ae->smctp_haddr));
memcpy(ae->smctp_haddr, cb->haddr, cb->halen);
}
}
rc = len;
if (flags & MSG_TRUNC)
rc = msglen;
out_free:
skb_free_datagram(sk, skb);
return rc;
}
/* We're done with the key; invalidate, stop reassembly, and remove from lists.
*/
static void __mctp_key_remove(struct mctp_sk_key *key, struct net *net,
unsigned long flags, unsigned long reason)
__releases(&key->lock)
__must_hold(&net->mctp.keys_lock)
{
struct sk_buff *skb;
trace_mctp_key_release(key, reason);
skb = key->reasm_head;
key->reasm_head = NULL;
key->reasm_dead = true;
key->valid = false;
mctp_dev_release_key(key->dev, key);
spin_unlock_irqrestore(&key->lock, flags);
if (!hlist_unhashed(&key->hlist)) {
hlist_del_init(&key->hlist);
hlist_del_init(&key->sklist);
/* unref for the lists */
mctp_key_unref(key);
}
kfree_skb(skb);
}
static int mctp_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
int val;
if (level != SOL_MCTP)
return -EINVAL;
if (optname == MCTP_OPT_ADDR_EXT) {
if (optlen != sizeof(int))
return -EINVAL;
if (copy_from_sockptr(&val, optval, sizeof(int)))
return -EFAULT;
msk->addr_ext = val;
return 0;
}
return -ENOPROTOOPT;
}
static int mctp_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
int len, val;
if (level != SOL_MCTP)
return -EINVAL;
if (get_user(len, optlen))
return -EFAULT;
if (optname == MCTP_OPT_ADDR_EXT) {
if (len != sizeof(int))
return -EINVAL;
val = !!msk->addr_ext;
if (copy_to_user(optval, &val, len))
return -EFAULT;
return 0;
}
return -EINVAL;
}
static int mctp_ioctl_alloctag(struct mctp_sock *msk, unsigned long arg)
{
struct net *net = sock_net(&msk->sk);
struct mctp_sk_key *key = NULL;
struct mctp_ioc_tag_ctl ctl;
unsigned long flags;
u8 tag;
if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))
return -EFAULT;
if (ctl.tag)
return -EINVAL;
if (ctl.flags)
return -EINVAL;
key = mctp_alloc_local_tag(msk, ctl.peer_addr, MCTP_ADDR_ANY,
true, &tag);
if (IS_ERR(key))
return PTR_ERR(key);
ctl.tag = tag | MCTP_TAG_OWNER | MCTP_TAG_PREALLOC;
if (copy_to_user((void __user *)arg, &ctl, sizeof(ctl))) {
unsigned long fl2;
/* Unwind our key allocation: the keys list lock needs to be
* taken before the individual key locks, and we need a valid
* flags value (fl2) to pass to __mctp_key_remove, hence the
* second spin_lock_irqsave() rather than a plain spin_lock().
*/
spin_lock_irqsave(&net->mctp.keys_lock, flags);
spin_lock_irqsave(&key->lock, fl2);
__mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_DROPPED);
mctp_key_unref(key);
spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
return -EFAULT;
}
mctp_key_unref(key);
return 0;
}
static int mctp_ioctl_droptag(struct mctp_sock *msk, unsigned long arg)
{
struct net *net = sock_net(&msk->sk);
struct mctp_ioc_tag_ctl ctl;
unsigned long flags, fl2;
struct mctp_sk_key *key;
struct hlist_node *tmp;
int rc;
u8 tag;
if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))
return -EFAULT;
if (ctl.flags)
return -EINVAL;
/* Must be a local tag, TO set, preallocated */
if ((ctl.tag & ~MCTP_TAG_MASK) != (MCTP_TAG_OWNER | MCTP_TAG_PREALLOC))
return -EINVAL;
tag = ctl.tag & MCTP_TAG_MASK;
rc = -EINVAL;
spin_lock_irqsave(&net->mctp.keys_lock, flags);
hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
/* we do an irqsave here, even though we know the irq state,
* so we have the flags to pass to __mctp_key_remove
*/
spin_lock_irqsave(&key->lock, fl2);
if (key->manual_alloc &&
ctl.peer_addr == key->peer_addr &&
tag == key->tag) {
__mctp_key_remove(key, net, fl2,
MCTP_TRACE_KEY_DROPPED);
rc = 0;
} else {
spin_unlock_irqrestore(&key->lock, fl2);
}
}
spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
return rc;
}
static int mctp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
switch (cmd) {
case SIOCMCTPALLOCTAG:
return mctp_ioctl_alloctag(msk, arg);
case SIOCMCTPDROPTAG:
return mctp_ioctl_droptag(msk, arg);
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static int mctp_compat_ioctl(struct socket *sock, unsigned int cmd,
unsigned long arg)
{
void __user *argp = compat_ptr(arg);
switch (cmd) {
/* These have compatible ptr layouts */
case SIOCMCTPALLOCTAG:
case SIOCMCTPDROPTAG:
return mctp_ioctl(sock, cmd, (unsigned long)argp);
}
return -ENOIOCTLCMD;
}
#endif
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 = mctp_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,
#ifdef CONFIG_COMPAT
.compat_ioctl = mctp_compat_ioctl,
#endif
};
static void mctp_sk_expire_keys(struct timer_list *timer)
{
struct mctp_sock *msk = container_of(timer, struct mctp_sock,
key_expiry);
struct net *net = sock_net(&msk->sk);
unsigned long next_expiry, flags, fl2;
struct mctp_sk_key *key;
struct hlist_node *tmp;
bool next_expiry_valid = false;
spin_lock_irqsave(&net->mctp.keys_lock, flags);
hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
/* don't expire. manual_alloc is immutable, no locking
* required.
*/
if (key->manual_alloc)
continue;
spin_lock_irqsave(&key->lock, fl2);
if (!time_after_eq(key->expiry, jiffies)) {
__mctp_key_remove(key, net, fl2,
MCTP_TRACE_KEY_TIMEOUT);
continue;
}
if (next_expiry_valid) {
if (time_before(key->expiry, next_expiry))
next_expiry = key->expiry;
} else {
next_expiry = key->expiry;
next_expiry_valid = true;
}
spin_unlock_irqrestore(&key->lock, fl2);
}
spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
if (next_expiry_valid)
mod_timer(timer, next_expiry);
}
static int mctp_sk_init(struct sock *sk)
{
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
INIT_HLIST_HEAD(&msk->keys);
timer_setup(&msk->key_expiry, mctp_sk_expire_keys, 0);
return 0;
}
static void mctp_sk_close(struct sock *sk, long timeout)
{
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
del_timer_sync(&msk->key_expiry);
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);
unsigned long flags, fl2;
struct mctp_sk_key *key;
struct hlist_node *tmp;
/* 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) {
spin_lock_irqsave(&key->lock, fl2);
__mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_CLOSED);
}
spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
}
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);
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);
}
subsys_initcall(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);