1 // SPDX-License-Identifier: GPL-2.0
3 * Management Component Transport Protocol (MCTP)
5 * Copyright (c) 2021 Code Construct
6 * Copyright (c) 2021 Google
9 #include <linux/compat.h>
10 #include <linux/if_arp.h>
11 #include <linux/net.h>
12 #include <linux/mctp.h>
13 #include <linux/module.h>
14 #include <linux/socket.h>
17 #include <net/mctpdevice.h>
20 #define CREATE_TRACE_POINTS
21 #include <trace/events/mctp.h>
23 /* socket implementation */
25 static void mctp_sk_expire_keys(struct timer_list *timer);
27 static int mctp_release(struct socket *sock)
29 struct sock *sk = sock->sk;
33 sk->sk_prot->close(sk, 0);
39 /* Generic sockaddr checks, padding checks only so far */
40 static bool mctp_sockaddr_is_ok(const struct sockaddr_mctp *addr)
42 return !addr->__smctp_pad0 && !addr->__smctp_pad1;
45 static bool mctp_sockaddr_ext_is_ok(const struct sockaddr_mctp_ext *addr)
47 return !addr->__smctp_pad0[0] &&
48 !addr->__smctp_pad0[1] &&
49 !addr->__smctp_pad0[2];
52 static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
54 struct sock *sk = sock->sk;
55 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
56 struct sockaddr_mctp *smctp;
59 if (addrlen < sizeof(*smctp))
62 if (addr->sa_family != AF_MCTP)
65 if (!capable(CAP_NET_BIND_SERVICE))
68 /* it's a valid sockaddr for MCTP, cast and do protocol checks */
69 smctp = (struct sockaddr_mctp *)addr;
71 if (!mctp_sockaddr_is_ok(smctp))
76 /* TODO: allow rebind */
81 msk->bind_net = smctp->smctp_network;
82 msk->bind_addr = smctp->smctp_addr.s_addr;
83 msk->bind_type = smctp->smctp_type & 0x7f; /* ignore the IC bit */
85 rc = sk->sk_prot->hash(sk);
93 static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
95 DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
96 const int hlen = MCTP_HEADER_MAXLEN + sizeof(struct mctp_hdr);
97 int rc, addrlen = msg->msg_namelen;
98 struct sock *sk = sock->sk;
99 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
100 struct mctp_skb_cb *cb;
101 struct mctp_route *rt;
105 const u8 tagbits = MCTP_TAG_MASK | MCTP_TAG_OWNER |
108 if (addrlen < sizeof(struct sockaddr_mctp))
110 if (addr->smctp_family != AF_MCTP)
112 if (!mctp_sockaddr_is_ok(addr))
114 if (addr->smctp_tag & ~tagbits)
116 /* can't preallocate a non-owned tag */
117 if (addr->smctp_tag & MCTP_TAG_PREALLOC &&
118 !(addr->smctp_tag & MCTP_TAG_OWNER))
122 /* TODO: connect()ed sockets */
123 return -EDESTADDRREQ;
126 if (!capable(CAP_NET_RAW))
129 if (addr->smctp_network == MCTP_NET_ANY)
130 addr->smctp_network = mctp_default_net(sock_net(sk));
132 skb = sock_alloc_send_skb(sk, hlen + 1 + len,
133 msg->msg_flags & MSG_DONTWAIT, &rc);
137 skb_reserve(skb, hlen);
139 /* set type as fist byte in payload */
140 *(u8 *)skb_put(skb, 1) = addr->smctp_type;
142 rc = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
148 cb->net = addr->smctp_network;
150 /* direct addressing */
151 if (msk->addr_ext && addrlen >= sizeof(struct sockaddr_mctp_ext)) {
152 DECLARE_SOCKADDR(struct sockaddr_mctp_ext *,
153 extaddr, msg->msg_name);
155 if (!mctp_sockaddr_ext_is_ok(extaddr) ||
156 extaddr->smctp_halen > sizeof(cb->haddr)) {
161 cb->ifindex = extaddr->smctp_ifindex;
162 cb->halen = extaddr->smctp_halen;
163 memcpy(cb->haddr, extaddr->smctp_haddr, cb->halen);
167 rt = mctp_route_lookup(sock_net(sk), addr->smctp_network,
168 addr->smctp_addr.s_addr);
175 rc = mctp_local_output(sk, rt, skb, addr->smctp_addr.s_addr,
185 static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
188 DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
189 struct sock *sk = sock->sk;
190 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
196 if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK))
199 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &rc);
208 /* extract message type, remove from data */
209 type = *((u8 *)skb->data);
210 msglen = skb->len - 1;
213 msg->msg_flags |= MSG_TRUNC;
217 rc = skb_copy_datagram_msg(skb, 1, msg, len);
221 sock_recv_ts_and_drops(msg, sk, skb);
224 struct mctp_skb_cb *cb = mctp_cb(skb);
225 /* TODO: expand mctp_skb_cb for header fields? */
226 struct mctp_hdr *hdr = mctp_hdr(skb);
228 addr = msg->msg_name;
229 addr->smctp_family = AF_MCTP;
230 addr->__smctp_pad0 = 0;
231 addr->smctp_network = cb->net;
232 addr->smctp_addr.s_addr = hdr->src;
233 addr->smctp_type = type;
234 addr->smctp_tag = hdr->flags_seq_tag &
235 (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
236 addr->__smctp_pad1 = 0;
237 msg->msg_namelen = sizeof(*addr);
240 DECLARE_SOCKADDR(struct sockaddr_mctp_ext *, ae,
242 msg->msg_namelen = sizeof(*ae);
243 ae->smctp_ifindex = cb->ifindex;
244 ae->smctp_halen = cb->halen;
245 memset(ae->__smctp_pad0, 0x0, sizeof(ae->__smctp_pad0));
246 memset(ae->smctp_haddr, 0x0, sizeof(ae->smctp_haddr));
247 memcpy(ae->smctp_haddr, cb->haddr, cb->halen);
253 if (flags & MSG_TRUNC)
257 skb_free_datagram(sk, skb);
261 /* We're done with the key; invalidate, stop reassembly, and remove from lists.
263 static void __mctp_key_remove(struct mctp_sk_key *key, struct net *net,
264 unsigned long flags, unsigned long reason)
265 __releases(&key->lock)
266 __must_hold(&net->mctp.keys_lock)
270 trace_mctp_key_release(key, reason);
271 skb = key->reasm_head;
272 key->reasm_head = NULL;
273 key->reasm_dead = true;
275 mctp_dev_release_key(key->dev, key);
276 spin_unlock_irqrestore(&key->lock, flags);
278 hlist_del(&key->hlist);
279 hlist_del(&key->sklist);
281 /* unref for the lists */
287 static int mctp_setsockopt(struct socket *sock, int level, int optname,
288 sockptr_t optval, unsigned int optlen)
290 struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
293 if (level != SOL_MCTP)
296 if (optname == MCTP_OPT_ADDR_EXT) {
297 if (optlen != sizeof(int))
299 if (copy_from_sockptr(&val, optval, sizeof(int)))
308 static int mctp_getsockopt(struct socket *sock, int level, int optname,
309 char __user *optval, int __user *optlen)
311 struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
314 if (level != SOL_MCTP)
317 if (get_user(len, optlen))
320 if (optname == MCTP_OPT_ADDR_EXT) {
321 if (len != sizeof(int))
323 val = !!msk->addr_ext;
324 if (copy_to_user(optval, &val, len))
332 static int mctp_ioctl_alloctag(struct mctp_sock *msk, unsigned long arg)
334 struct net *net = sock_net(&msk->sk);
335 struct mctp_sk_key *key = NULL;
336 struct mctp_ioc_tag_ctl ctl;
340 if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))
349 key = mctp_alloc_local_tag(msk, ctl.peer_addr, MCTP_ADDR_ANY,
354 ctl.tag = tag | MCTP_TAG_OWNER | MCTP_TAG_PREALLOC;
355 if (copy_to_user((void __user *)arg, &ctl, sizeof(ctl))) {
356 spin_lock_irqsave(&key->lock, flags);
357 __mctp_key_remove(key, net, flags, MCTP_TRACE_KEY_DROPPED);
366 static int mctp_ioctl_droptag(struct mctp_sock *msk, unsigned long arg)
368 struct net *net = sock_net(&msk->sk);
369 struct mctp_ioc_tag_ctl ctl;
370 unsigned long flags, fl2;
371 struct mctp_sk_key *key;
372 struct hlist_node *tmp;
376 if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))
382 /* Must be a local tag, TO set, preallocated */
383 if ((ctl.tag & ~MCTP_TAG_MASK) != (MCTP_TAG_OWNER | MCTP_TAG_PREALLOC))
386 tag = ctl.tag & MCTP_TAG_MASK;
389 spin_lock_irqsave(&net->mctp.keys_lock, flags);
390 hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
391 /* we do an irqsave here, even though we know the irq state,
392 * so we have the flags to pass to __mctp_key_remove
394 spin_lock_irqsave(&key->lock, fl2);
395 if (key->manual_alloc &&
396 ctl.peer_addr == key->peer_addr &&
398 __mctp_key_remove(key, net, fl2,
399 MCTP_TRACE_KEY_DROPPED);
402 spin_unlock_irqrestore(&key->lock, fl2);
405 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
410 static int mctp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
412 struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
415 case SIOCMCTPALLOCTAG:
416 return mctp_ioctl_alloctag(msk, arg);
417 case SIOCMCTPDROPTAG:
418 return mctp_ioctl_droptag(msk, arg);
425 static int mctp_compat_ioctl(struct socket *sock, unsigned int cmd,
428 void __user *argp = compat_ptr(arg);
431 /* These have compatible ptr layouts */
432 case SIOCMCTPALLOCTAG:
433 case SIOCMCTPDROPTAG:
434 return mctp_ioctl(sock, cmd, (unsigned long)argp);
441 static const struct proto_ops mctp_dgram_ops = {
443 .release = mctp_release,
445 .connect = sock_no_connect,
446 .socketpair = sock_no_socketpair,
447 .accept = sock_no_accept,
448 .getname = sock_no_getname,
449 .poll = datagram_poll,
451 .gettstamp = sock_gettstamp,
452 .listen = sock_no_listen,
453 .shutdown = sock_no_shutdown,
454 .setsockopt = mctp_setsockopt,
455 .getsockopt = mctp_getsockopt,
456 .sendmsg = mctp_sendmsg,
457 .recvmsg = mctp_recvmsg,
458 .mmap = sock_no_mmap,
459 .sendpage = sock_no_sendpage,
461 .compat_ioctl = mctp_compat_ioctl,
465 static void mctp_sk_expire_keys(struct timer_list *timer)
467 struct mctp_sock *msk = container_of(timer, struct mctp_sock,
469 struct net *net = sock_net(&msk->sk);
470 unsigned long next_expiry, flags, fl2;
471 struct mctp_sk_key *key;
472 struct hlist_node *tmp;
473 bool next_expiry_valid = false;
475 spin_lock_irqsave(&net->mctp.keys_lock, flags);
477 hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
478 /* don't expire. manual_alloc is immutable, no locking
481 if (key->manual_alloc)
484 spin_lock_irqsave(&key->lock, fl2);
485 if (!time_after_eq(key->expiry, jiffies)) {
486 __mctp_key_remove(key, net, fl2,
487 MCTP_TRACE_KEY_TIMEOUT);
491 if (next_expiry_valid) {
492 if (time_before(key->expiry, next_expiry))
493 next_expiry = key->expiry;
495 next_expiry = key->expiry;
496 next_expiry_valid = true;
498 spin_unlock_irqrestore(&key->lock, fl2);
501 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
503 if (next_expiry_valid)
504 mod_timer(timer, next_expiry);
507 static int mctp_sk_init(struct sock *sk)
509 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
511 INIT_HLIST_HEAD(&msk->keys);
512 timer_setup(&msk->key_expiry, mctp_sk_expire_keys, 0);
516 static void mctp_sk_close(struct sock *sk, long timeout)
518 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
520 del_timer_sync(&msk->key_expiry);
521 sk_common_release(sk);
524 static int mctp_sk_hash(struct sock *sk)
526 struct net *net = sock_net(sk);
528 mutex_lock(&net->mctp.bind_lock);
529 sk_add_node_rcu(sk, &net->mctp.binds);
530 mutex_unlock(&net->mctp.bind_lock);
535 static void mctp_sk_unhash(struct sock *sk)
537 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
538 struct net *net = sock_net(sk);
539 unsigned long flags, fl2;
540 struct mctp_sk_key *key;
541 struct hlist_node *tmp;
543 /* remove from any type-based binds */
544 mutex_lock(&net->mctp.bind_lock);
545 sk_del_node_init_rcu(sk);
546 mutex_unlock(&net->mctp.bind_lock);
548 /* remove tag allocations */
549 spin_lock_irqsave(&net->mctp.keys_lock, flags);
550 hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
551 spin_lock_irqsave(&key->lock, fl2);
552 __mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_CLOSED);
554 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
557 static struct proto mctp_proto = {
559 .owner = THIS_MODULE,
560 .obj_size = sizeof(struct mctp_sock),
561 .init = mctp_sk_init,
562 .close = mctp_sk_close,
563 .hash = mctp_sk_hash,
564 .unhash = mctp_sk_unhash,
567 static int mctp_pf_create(struct net *net, struct socket *sock,
568 int protocol, int kern)
570 const struct proto_ops *ops;
576 return -EPROTONOSUPPORT;
578 /* only datagram sockets are supported */
579 if (sock->type != SOCK_DGRAM)
580 return -ESOCKTNOSUPPORT;
583 ops = &mctp_dgram_ops;
585 sock->state = SS_UNCONNECTED;
588 sk = sk_alloc(net, PF_MCTP, GFP_KERNEL, proto, kern);
592 sock_init_data(sock, sk);
595 if (sk->sk_prot->init)
596 rc = sk->sk_prot->init(sk);
609 static struct net_proto_family mctp_pf = {
611 .create = mctp_pf_create,
612 .owner = THIS_MODULE,
615 static __init int mctp_init(void)
619 /* ensure our uapi tag definitions match the header format */
620 BUILD_BUG_ON(MCTP_TAG_OWNER != MCTP_HDR_FLAG_TO);
621 BUILD_BUG_ON(MCTP_TAG_MASK != MCTP_HDR_TAG_MASK);
623 pr_info("mctp: management component transport protocol core\n");
625 rc = sock_register(&mctp_pf);
629 rc = proto_register(&mctp_proto, 0);
633 rc = mctp_routes_init();
635 goto err_unreg_proto;
637 rc = mctp_neigh_init();
639 goto err_unreg_proto;
646 proto_unregister(&mctp_proto);
648 sock_unregister(PF_MCTP);
653 static __exit void mctp_exit(void)
658 proto_unregister(&mctp_proto);
659 sock_unregister(PF_MCTP);
662 subsys_initcall(mctp_init);
663 module_exit(mctp_exit);
665 MODULE_DESCRIPTION("MCTP core");
666 MODULE_LICENSE("GPL v2");
667 MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");
669 MODULE_ALIAS_NETPROTO(PF_MCTP);