af_iucv.c

linux 内核源代码

	struct iucv_sock *iucv = iucv_sk(sk);
	struct sk_buff *skb;
	struct iucv_message txmsg;
	int err;

	err = sock_error(sk);
	if (err)
		return err;

	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	lock_sock(sk);

	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		err = -EPIPE;
		goto out;
	}

	if (sk->sk_state == IUCV_CONNECTED) {
		if (!(skb = sock_alloc_send_skb(sk, len,
						msg->msg_flags & MSG_DONTWAIT,
						&err)))
			goto out;

		if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
			err = -EFAULT;
			goto fail;
		}

		txmsg.class = 0;
		txmsg.tag = iucv->send_tag++;
		memcpy(skb->cb, &txmsg.tag, 4);
		skb_queue_tail(&iucv->send_skb_q, skb);
		err = iucv_message_send(iucv->path, &txmsg, 0, 0,
					(void *) skb->data, skb->len);
		if (err) {
			if (err == 3)
				printk(KERN_ERR "AF_IUCV msg limit exceeded\n");
			skb_unlink(skb, &iucv->send_skb_q);
			err = -EPIPE;
			goto fail;
		}

	} else {
		err = -ENOTCONN;
		goto out;
	}

	release_sock(sk);
	return len;

fail:
	kfree_skb(skb);
out:
	release_sock(sk);
	return err;
}

static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
{
	int dataleft, size, copied = 0;
	struct sk_buff *nskb;

	dataleft = len;
	while (dataleft) {
		if (dataleft >= sk->sk_rcvbuf / 4)
			size = sk->sk_rcvbuf / 4;
		else
			size = dataleft;

		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
		if (!nskb)
			return -ENOMEM;

		memcpy(nskb->data, skb->data + copied, size);
		copied += size;
		dataleft -= size;

		skb_reset_transport_header(nskb);
		skb_reset_network_header(nskb);
		nskb->len = size;

		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
	}

	return 0;
}

static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
				 struct iucv_path *path,
				 struct iucv_message *msg)
{
	int rc;

	if (msg->flags & IPRMDATA) {
		skb->data = NULL;
		skb->len = 0;
	} else {
		rc = iucv_message_receive(path, msg, 0, skb->data,
					  msg->length, NULL);
		if (rc) {
			kfree_skb(skb);
			return;
		}
		if (skb->truesize >= sk->sk_rcvbuf / 4) {
			rc = iucv_fragment_skb(sk, skb, msg->length);
			kfree_skb(skb);
			skb = NULL;
			if (rc) {
				iucv_path_sever(path, NULL);
				return;
			}
			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
		} else {
			skb_reset_transport_header(skb);
			skb_reset_network_header(skb);
			skb->len = msg->length;
		}
	}

	if (sock_queue_rcv_skb(sk, skb))
		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
}

static void iucv_process_message_q(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	struct sk_buff *skb;
	struct sock_msg_q *p, *n;

	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
		skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
		if (!skb)
			break;
		iucv_process_message(sk, skb, p->path, &p->msg);
		list_del(&p->list);
		kfree(p);
		if (!skb_queue_empty(&iucv->backlog_skb_q))
			break;
	}
}

static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
			     struct msghdr *msg, size_t len, int flags)
{
	int noblock = flags & MSG_DONTWAIT;
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	int target, copied = 0;
	struct sk_buff *skb, *rskb, *cskb;
	int err = 0;

	if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
	    skb_queue_empty(&iucv->backlog_skb_q) &&
	    skb_queue_empty(&sk->sk_receive_queue) &&
	    list_empty(&iucv->message_q.list))
		return 0;

	if (flags & (MSG_OOB))
		return -EOPNOTSUPP;

	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb) {
		if (sk->sk_shutdown & RCV_SHUTDOWN)
			return 0;
		return err;
	}

	copied = min_t(unsigned int, skb->len, len);

	cskb = skb;
	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
		skb_queue_head(&sk->sk_receive_queue, skb);
		if (copied == 0)
			return -EFAULT;
		goto done;
	}

	len -= copied;

	/* Mark read part of skb as used */
	if (!(flags & MSG_PEEK)) {
		skb_pull(skb, copied);

		if (skb->len) {
			skb_queue_head(&sk->sk_receive_queue, skb);
			goto done;
		}

		kfree_skb(skb);

		/* Queue backlog skbs */
		rskb = skb_dequeue(&iucv->backlog_skb_q);
		while (rskb) {
			if (sock_queue_rcv_skb(sk, rskb)) {
				skb_queue_head(&iucv->backlog_skb_q,
						rskb);
				break;
			} else {
				rskb = skb_dequeue(&iucv->backlog_skb_q);
			}
		}
		if (skb_queue_empty(&iucv->backlog_skb_q)) {
			spin_lock_bh(&iucv->message_q.lock);
			if (!list_empty(&iucv->message_q.list))
				iucv_process_message_q(sk);
			spin_unlock_bh(&iucv->message_q.lock);
		}

	} else
		skb_queue_head(&sk->sk_receive_queue, skb);

done:
	return err ? : copied;
}

static inline unsigned int iucv_accept_poll(struct sock *parent)
{
	struct iucv_sock *isk, *n;
	struct sock *sk;

	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
		sk = (struct sock *) isk;

		if (sk->sk_state == IUCV_CONNECTED)
			return POLLIN | POLLRDNORM;
	}

	return 0;
}

unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
			    poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask = 0;

	poll_wait(file, sk->sk_sleep, wait);

	if (sk->sk_state == IUCV_LISTEN)
		return iucv_accept_poll(sk);

	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
		mask |= POLLERR;

	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLRDHUP;

	if (sk->sk_shutdown == SHUTDOWN_MASK)
		mask |= POLLHUP;

	if (!skb_queue_empty(&sk->sk_receive_queue) ||
	    (sk->sk_shutdown & RCV_SHUTDOWN))
		mask |= POLLIN | POLLRDNORM;

	if (sk->sk_state == IUCV_CLOSED)
		mask |= POLLHUP;

	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
		mask |= POLLIN;

	if (sock_writeable(sk))
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
	else
		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);

	return mask;
}

static int iucv_sock_shutdown(struct socket *sock, int how)
{
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	struct iucv_message txmsg;
	int err = 0;
	u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};

	how++;

	if ((how & ~SHUTDOWN_MASK) || !how)
		return -EINVAL;

	lock_sock(sk);
	switch (sk->sk_state) {
	case IUCV_CLOSED:
		err = -ENOTCONN;
		goto fail;

	default:
		sk->sk_shutdown |= how;
		break;
	}

	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
		txmsg.class = 0;
		txmsg.tag = 0;
		err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
					(void *) prmmsg, 8);
		if (err) {
			switch (err) {
			case 1:
				err = -ENOTCONN;
				break;
			case 2:
				err = -ECONNRESET;
				break;
			default:
				err = -ENOTCONN;
				break;
			}
		}
	}

	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
		err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
		if (err)
			err = -ENOTCONN;

		skb_queue_purge(&sk->sk_receive_queue);
	}

	/* Wake up anyone sleeping in poll */
	sk->sk_state_change(sk);

fail:
	release_sock(sk);
	return err;
}

static int iucv_sock_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	int err = 0;

	if (!sk)
		return 0;

	iucv_sock_close(sk);

	/* Unregister with IUCV base support */
	if (iucv_sk(sk)->path) {
		iucv_path_sever(iucv_sk(sk)->path, NULL);
		iucv_path_free(iucv_sk(sk)->path);
		iucv_sk(sk)->path = NULL;
	}

	sock_orphan(sk);
	iucv_sock_kill(sk);
	return err;
}

/* Callback wrappers - called from iucv base support */
static int iucv_callback_connreq(struct iucv_path *path,
				 u8 ipvmid[8], u8 ipuser[16])
{
	unsigned char user_data[16];
	unsigned char nuser_data[16];
	unsigned char src_name[8];
	struct hlist_node *node;
	struct sock *sk, *nsk;
	struct iucv_sock *iucv, *niucv;
	int err;

	memcpy(src_name, ipuser, 8);
	EBCASC(src_name, 8);
	/* Find out if this path belongs to af_iucv. */
	read_lock(&iucv_sk_list.lock);
	iucv = NULL;
	sk = NULL;
	sk_for_each(sk, node, &iucv_sk_list.head)
		if (sk->sk_state == IUCV_LISTEN &&
		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
			/*
			 * Found a listening socket with
			 * src_name == ipuser[0-7].
			 */
			iucv = iucv_sk(sk);
			break;
		}
	read_unlock(&iucv_sk_list.lock);
	if (!iucv)
		/* No socket found, not one of our paths. */
		return -EINVAL;

	bh_lock_sock(sk);

	/* Check if parent socket is listening */
	low_nmcpy(user_data, iucv->src_name);
	high_nmcpy(user_data, iucv->dst_name);
	ASCEBC(user_data, sizeof(user_data));
	if (sk->sk_state != IUCV_LISTEN) {
		err = iucv_path_sever(path, user_data);
		goto fail;
	}

	/* Check for backlog size */
	if (sk_acceptq_is_full(sk)) {
		err = iucv_path_sever(path, user_data);
		goto fail;
	}

	/* Create the new socket */
	nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
	if (!nsk) {
		err = iucv_path_sever(path, user_data);
		goto fail;
	}

	niucv = iucv_sk(nsk);
	iucv_sock_init(nsk, sk);

	/* Set the new iucv_sock */
	memcpy(niucv->dst_name, ipuser + 8, 8);
	EBCASC(niucv->dst_name, 8);
	memcpy(niucv->dst_user_id, ipvmid, 8);
	memcpy(niucv->src_name, iucv->src_name, 8);
	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
	niucv->path = path;

	/* Call iucv_accept */
	high_nmcpy(nuser_data, ipuser + 8);
	memcpy(nuser_data + 8, niucv->src_name, 8);
	ASCEBC(nuser_data + 8, 8);

	path->msglim = IUCV_QUEUELEN_DEFAULT;
	err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
	if (err) {
		err = iucv_path_sever(path, user_data);
		goto fail;
	}

	iucv_accept_enqueue(sk, nsk);

	/* Wake up accept */
	nsk->sk_state = IUCV_CONNECTED;
	sk->sk_data_ready(sk, 1);
	err = 0;
fail:
	bh_unlock_sock(sk);
	return 0;
}

static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
{
	struct sock *sk = path->private;

	sk->sk_state = IUCV_CONNECTED;
	sk->sk_state_change(sk);
}

static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
{
	struct sock *sk = path->private;
	struct iucv_sock *iucv = iucv_sk(sk);
	struct sk_buff *skb;
	struct sock_msg_q *save_msg;
	int len;

	if (sk->sk_shutdown & RCV_SHUTDOWN)
		return;

	if (!list_empty(&iucv->message_q.list) ||
	    !skb_queue_empty(&iucv->backlog_skb_q))
		goto save_message;

	len = atomic_read(&sk->sk_rmem_alloc);
	len += msg->length + sizeof(struct sk_buff);
	if (len > sk->sk_rcvbuf)
		goto save_message;

	skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
	if (!skb)
		goto save_message;

	spin_lock(&iucv->message_q.lock);
	iucv_process_message(sk, skb, path, msg);
	spin_unlock(&iucv->message_q.lock);

	return;

save_message:
	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
	save_msg->path = path;
	save_msg->msg = *msg;

	spin_lock(&iucv->message_q.lock);
	list_add_tail(&save_msg->list, &iucv->message_q.list);
	spin_unlock(&iucv->message_q.lock);
}

static void iucv_callback_txdone(struct iucv_path *path,
				 struct iucv_message *msg)
{
	struct sock *sk = path->private;
	struct sk_buff *this;
	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
	struct sk_buff *list_skb = list->next;
	unsigned long flags;

	if (list_skb) {
		spin_lock_irqsave(&list->lock, flags);

		do {
			this = list_skb;
			list_skb = list_skb->next;
		} while (memcmp(&msg->tag, this->cb, 4) && list_skb);

		spin_unlock_irqrestore(&list->lock, flags);

		skb_unlink(this, &iucv_sk(sk)->send_skb_q);
		kfree_skb(this);
	}

	if (sk->sk_state == IUCV_CLOSING) {
		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
			sk->sk_state = IUCV_CLOSED;
			sk->sk_state_change(sk);
		}
	}

}

static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
{
	struct sock *sk = path->private;

	if (!list_empty(&iucv_sk(sk)->accept_q))
		sk->sk_state = IUCV_SEVERED;
	else
		sk->sk_state = IUCV_DISCONN;

	sk->sk_state_change(sk);
}

static struct proto_ops iucv_sock_ops = {
	.family		= PF_IUCV,
	.owner		= THIS_MODULE,
	.release	= iucv_sock_release,
	.bind		= iucv_sock_bind,
	.connect	= iucv_sock_connect,
	.listen		= iucv_sock_listen,
	.accept		= iucv_sock_accept,
	.getname	= iucv_sock_getname,
	.sendmsg	= iucv_sock_sendmsg,
	.recvmsg	= iucv_sock_recvmsg,
	.poll		= iucv_sock_poll,
	.ioctl		= sock_no_ioctl,
	.mmap		= sock_no_mmap,
	.socketpair	= sock_no_socketpair,
	.shutdown	= iucv_sock_shutdown,
	.setsockopt	= sock_no_setsockopt,
	.getsockopt	= sock_no_getsockopt
};

static struct net_proto_family iucv_sock_family_ops = {
	.family	= AF_IUCV,
	.owner	= THIS_MODULE,
	.create	= iucv_sock_create,
};

static int __init afiucv_init(void)
{
	int err;

	if (!MACHINE_IS_VM) {
		printk(KERN_ERR "AF_IUCV connection needs VM as base\n");
		err = -EPROTONOSUPPORT;
		goto out;
	}
	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
	if (unlikely(err)) {
		printk(KERN_ERR "AF_IUCV needs the VM userid\n");
		err = -EPROTONOSUPPORT;
		goto out;
	}

	err = iucv_register(&af_iucv_handler, 0);
	if (err)
		goto out;
	err = proto_register(&iucv_proto, 0);
	if (err)
		goto out_iucv;
	err = sock_register(&iucv_sock_family_ops);
	if (err)
		goto out_proto;
	printk(KERN_INFO "AF_IUCV lowlevel driver initialized\n");
	return 0;

out_proto:
	proto_unregister(&iucv_proto);
out_iucv:
	iucv_unregister(&af_iucv_handler, 0);
out:
	return err;
}

static void __exit afiucv_exit(void)
{
	sock_unregister(PF_IUCV);
	proto_unregister(&iucv_proto);
	iucv_unregister(&af_iucv_handler, 0);

	printk(KERN_INFO "AF_IUCV lowlevel driver unloaded\n");
}

module_init(afiucv_init);
module_exit(afiucv_exit);

MODULE_AUTHOR("Jennifer Hunt <[e-mail]>");
MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_IUCV);