net/nfc/rawsock.c

Source file repositories/reference/linux-study-clean/net/nfc/rawsock.c

File Facts

System
Linux kernel
Corpus path
net/nfc/rawsock.c
Extension
.c
Size
9585 bytes
Lines
433
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct proto_ops rawsock_ops = {
	.family         = PF_NFC,
	.owner          = THIS_MODULE,
	.release        = rawsock_release,
	.bind           = sock_no_bind,
	.connect        = rawsock_connect,
	.socketpair     = sock_no_socketpair,
	.accept         = sock_no_accept,
	.getname        = sock_no_getname,
	.poll           = datagram_poll,
	.ioctl          = sock_no_ioctl,
	.listen         = sock_no_listen,
	.shutdown       = sock_no_shutdown,
	.sendmsg        = rawsock_sendmsg,
	.recvmsg        = rawsock_recvmsg,
	.mmap           = sock_no_mmap,
};

static const struct proto_ops rawsock_raw_ops = {
	.family         = PF_NFC,
	.owner          = THIS_MODULE,
	.release        = rawsock_release,
	.bind           = sock_no_bind,
	.connect        = sock_no_connect,
	.socketpair     = sock_no_socketpair,
	.accept         = sock_no_accept,
	.getname        = sock_no_getname,
	.poll           = datagram_poll,
	.ioctl          = sock_no_ioctl,
	.listen         = sock_no_listen,
	.shutdown       = sock_no_shutdown,
	.sendmsg        = sock_no_sendmsg,
	.recvmsg        = rawsock_recvmsg,
	.mmap           = sock_no_mmap,
};

static void rawsock_destruct(struct sock *sk)
{
	pr_debug("sk=%p\n", sk);

	if (sk->sk_state == TCP_ESTABLISHED) {
		nfc_deactivate_target(nfc_rawsock(sk)->dev,
				      nfc_rawsock(sk)->target_idx,
				      NFC_TARGET_MODE_IDLE);
		nfc_put_device(nfc_rawsock(sk)->dev);
	}

	skb_queue_purge(&sk->sk_receive_queue);

	if (!sock_flag(sk, SOCK_DEAD)) {
		pr_err("Freeing alive NFC raw socket %p\n", sk);
		return;
	}
}

static int rawsock_create(struct net *net, struct socket *sock,
			  const struct nfc_protocol *nfc_proto, int kern)
{
	struct sock *sk;

	pr_debug("sock=%p\n", sock);

	if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW))
		return -ESOCKTNOSUPPORT;

	if (sock->type == SOCK_RAW) {
		if (!ns_capable(net->user_ns, CAP_NET_RAW))
			return -EPERM;
		sock->ops = &rawsock_raw_ops;
	} else {
		sock->ops = &rawsock_ops;
	}

	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto, kern);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sk->sk_protocol = nfc_proto->id;
	sk->sk_destruct = rawsock_destruct;
	sock->state = SS_UNCONNECTED;
	if (sock->type == SOCK_RAW)
		nfc_sock_link(&raw_sk_list, sk);
	else {
		INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
		nfc_rawsock(sk)->tx_work_scheduled = false;
	}

	return 0;
}

Annotation

Implementation Notes