af_ax25.c

linux 内核源代码

		goto out;

	newsk		 = skb->sk;
	newsk->sk_socket = newsock;
	newsk->sk_sleep	 = &newsock->wait;

	/* Now attach up the new socket */
	kfree_skb(skb);
	sk->sk_ack_backlog--;
	newsock->sk    = newsk;
	newsock->state = SS_CONNECTED;

out:
	release_sock(sk);

	return err;
}

static int ax25_getname(struct socket *sock, struct sockaddr *uaddr,
	int *uaddr_len, int peer)
{
	struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
	struct sock *sk = sock->sk;
	unsigned char ndigi, i;
	ax25_cb *ax25;
	int err = 0;

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	if (peer != 0) {
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -ENOTCONN;
			goto out;
		}

		fsa->fsa_ax25.sax25_family = AF_AX25;
		fsa->fsa_ax25.sax25_call   = ax25->dest_addr;
		fsa->fsa_ax25.sax25_ndigis = 0;

		if (ax25->digipeat != NULL) {
			ndigi = ax25->digipeat->ndigi;
			fsa->fsa_ax25.sax25_ndigis = ndigi;
			for (i = 0; i < ndigi; i++)
				fsa->fsa_digipeater[i] =
						ax25->digipeat->calls[i];
		}
	} else {
		fsa->fsa_ax25.sax25_family = AF_AX25;
		fsa->fsa_ax25.sax25_call   = ax25->source_addr;
		fsa->fsa_ax25.sax25_ndigis = 1;
		if (ax25->ax25_dev != NULL) {
			memcpy(&fsa->fsa_digipeater[0],
			       ax25->ax25_dev->dev->dev_addr, AX25_ADDR_LEN);
		} else {
			fsa->fsa_digipeater[0] = null_ax25_address;
		}
	}
	*uaddr_len = sizeof (struct full_sockaddr_ax25);

out:
	release_sock(sk);

	return err;
}

static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{
	struct sockaddr_ax25 *usax = (struct sockaddr_ax25 *)msg->msg_name;
	struct sock *sk = sock->sk;
	struct sockaddr_ax25 sax;
	struct sk_buff *skb;
	ax25_digi dtmp, *dp;
	ax25_cb *ax25;
	size_t size;
	int lv, err, addr_len = msg->msg_namelen;

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
		return -EINVAL;

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	if (sock_flag(sk, SOCK_ZAPPED)) {
		err = -EADDRNOTAVAIL;
		goto out;
	}

	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		send_sig(SIGPIPE, current, 0);
		err = -EPIPE;
		goto out;
	}

	if (ax25->ax25_dev == NULL) {
		err = -ENETUNREACH;
		goto out;
	}

	if (len > ax25->ax25_dev->dev->mtu) {
		err = -EMSGSIZE;
		goto out;
	}

	if (usax != NULL) {
		if (usax->sax25_family != AF_AX25) {
			err = -EINVAL;
			goto out;
		}

		if (addr_len == sizeof(struct sockaddr_ax25))
			/* ax25_sendmsg(): uses obsolete socket structure */
			;
		else if (addr_len != sizeof(struct full_sockaddr_ax25))
			/* support for old structure may go away some time
			 * ax25_sendmsg(): uses old (6 digipeater)
			 * socket structure.
			 */
			if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
			    (addr_len > sizeof(struct full_sockaddr_ax25))) {
				err = -EINVAL;
				goto out;
			}


		if (addr_len > sizeof(struct sockaddr_ax25) && usax->sax25_ndigis != 0) {
			int ct           = 0;
			struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax;

			/* Valid number of digipeaters ? */
			if (usax->sax25_ndigis < 1 || usax->sax25_ndigis > AX25_MAX_DIGIS) {
				err = -EINVAL;
				goto out;
			}

			dtmp.ndigi      = usax->sax25_ndigis;

			while (ct < usax->sax25_ndigis) {
				dtmp.repeated[ct] = 0;
				dtmp.calls[ct]    = fsa->fsa_digipeater[ct];
				ct++;
			}

			dtmp.lastrepeat = 0;
		}

		sax = *usax;
		if (sk->sk_type == SOCK_SEQPACKET &&
		    ax25cmp(&ax25->dest_addr, &sax.sax25_call)) {
			err = -EISCONN;
			goto out;
		}
		if (usax->sax25_ndigis == 0)
			dp = NULL;
		else
			dp = &dtmp;
	} else {
		/*
		 *	FIXME: 1003.1g - if the socket is like this because
		 *	it has become closed (not started closed) and is VC
		 *	we ought to SIGPIPE, EPIPE
		 */
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -ENOTCONN;
			goto out;
		}
		sax.sax25_family = AF_AX25;
		sax.sax25_call   = ax25->dest_addr;
		dp = ax25->digipeat;
	}

	SOCK_DEBUG(sk, "AX.25: sendto: Addresses built.\n");

	/* Build a packet */
	SOCK_DEBUG(sk, "AX.25: sendto: building packet.\n");

	/* Assume the worst case */
	size = len + ax25->ax25_dev->dev->hard_header_len;

	skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto out;

	skb_reserve(skb, size - len);

	SOCK_DEBUG(sk, "AX.25: Appending user data\n");

	/* User data follows immediately after the AX.25 data */
	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
		err = -EFAULT;
		kfree_skb(skb);
		goto out;
	}

	skb_reset_network_header(skb);

	/* Add the PID if one is not supplied by the user in the skb */
	if (!ax25->pidincl)
		*skb_push(skb, 1) = sk->sk_protocol;

	SOCK_DEBUG(sk, "AX.25: Transmitting buffer\n");

	if (sk->sk_type == SOCK_SEQPACKET) {
		/* Connected mode sockets go via the LAPB machine */
		if (sk->sk_state != TCP_ESTABLISHED) {
			kfree_skb(skb);
			err = -ENOTCONN;
			goto out;
		}

		/* Shove it onto the queue and kick */
		ax25_output(ax25, ax25->paclen, skb);

		err = len;
		goto out;
	}

	skb_push(skb, 1 + ax25_addr_size(dp));

	SOCK_DEBUG(sk, "Building AX.25 Header (dp=%p).\n", dp);

	if (dp != NULL)
		SOCK_DEBUG(sk, "Num digipeaters=%d\n", dp->ndigi);

	/* Build an AX.25 header */
	lv = ax25_addr_build(skb->data, &ax25->source_addr, &sax.sax25_call,
			     dp, AX25_COMMAND, AX25_MODULUS);

	SOCK_DEBUG(sk, "Built header (%d bytes)\n",lv);

	skb_set_transport_header(skb, lv);

	SOCK_DEBUG(sk, "base=%p pos=%p\n",
		   skb->data, skb_transport_header(skb));

	*skb_transport_header(skb) = AX25_UI;

	/* Datagram frames go straight out of the door as UI */
	ax25_queue_xmit(skb, ax25->ax25_dev->dev);

	err = len;

out:
	release_sock(sk);

	return err;
}

static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
	struct msghdr *msg, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied;
	int err = 0;

	lock_sock(sk);
	/*
	 * 	This works for seqpacket too. The receiver has ordered the
	 *	queue for us! We do one quick check first though
	 */
	if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_ESTABLISHED) {
		err =  -ENOTCONN;
		goto out;
	}

	/* Now we can treat all alike */
	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
				flags & MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto out;

	if (!ax25_sk(sk)->pidincl)
		skb_pull(skb, 1);		/* Remove PID */

	skb_reset_transport_header(skb);
	copied = skb->len;

	if (copied > size) {
		copied = size;
		msg->msg_flags |= MSG_TRUNC;
	}

	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);

	if (msg->msg_namelen != 0) {
		struct sockaddr_ax25 *sax = (struct sockaddr_ax25 *)msg->msg_name;
		ax25_digi digi;
		ax25_address src;
		const unsigned char *mac = skb_mac_header(skb);

		ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL,
				&digi, NULL, NULL);
		sax->sax25_family = AF_AX25;
		/* We set this correctly, even though we may not let the
		   application know the digi calls further down (because it
		   did NOT ask to know them).  This could get political... **/
		sax->sax25_ndigis = digi.ndigi;
		sax->sax25_call   = src;

		if (sax->sax25_ndigis != 0) {
			int ct;
			struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)sax;

			for (ct = 0; ct < digi.ndigi; ct++)
				fsa->fsa_digipeater[ct] = digi.calls[ct];
		}
		msg->msg_namelen = sizeof(struct full_sockaddr_ax25);
	}

	skb_free_datagram(sk, skb);
	err = copied;

out:
	release_sock(sk);

	return err;
}

static int ax25_shutdown(struct socket *sk, int how)
{
	/* FIXME - generate DM and RNR states */
	return -EOPNOTSUPP;
}

static int ax25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	void __user *argp = (void __user *)arg;
	int res = 0;

	lock_sock(sk);
	switch (cmd) {
	case TIOCOUTQ: {
		long amount;
		amount = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
		if (amount < 0)
			amount = 0;
		res = put_user(amount, (int __user *)argp);
		break;
	}

	case TIOCINQ: {
		struct sk_buff *skb;
		long amount = 0L;
		/* These two are safe on a single CPU system as only user tasks fiddle here */
		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
			amount = skb->len;
		res = put_user(amount, (int __user *) argp);
		break;
	}

	case SIOCGSTAMP:
		res = sock_get_timestamp(sk, argp);
		break;

	case SIOCGSTAMPNS:
		res = sock_get_timestampns(sk, argp);
		break;

	case SIOCAX25ADDUID:	/* Add a uid to the uid/call map table */
	case SIOCAX25DELUID:	/* Delete a uid from the uid/call map table */
	case SIOCAX25GETUID: {
		struct sockaddr_ax25 sax25;
		if (copy_from_user(&sax25, argp, sizeof(sax25))) {
			res = -EFAULT;
			break;
		}
		res = ax25_uid_ioctl(cmd, &sax25);
		break;
	}

	case SIOCAX25NOUID: {	/* Set the default policy (default/bar) */
		long amount;
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		if (get_user(amount, (long __user *)argp)) {
			res = -EFAULT;
			break;
		}
		if (amount > AX25_NOUID_BLOCK) {
			res = -EINVAL;
			break;
		}
		ax25_uid_policy = amount;
		res = 0;
		break;
	}

	case SIOCADDRT:
	case SIOCDELRT:
	case SIOCAX25OPTRT:
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		res = ax25_rt_ioctl(cmd, argp);
		break;

	case SIOCAX25CTLCON:
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		res = ax25_ctl_ioctl(cmd, argp);
		break;

	case SIOCAX25GETINFO:
	case SIOCAX25GETINFOOLD: {
		ax25_cb *ax25 = ax25_sk(sk);
		struct ax25_info_struct ax25_info;

		ax25_info.t1        = ax25->t1   / HZ;
		ax25_info.t2        = ax25->t2   / HZ;
		ax25_info.t3        = ax25->t3   / HZ;
		ax25_info.idle      = ax25->idle / (60 * HZ);
		ax25_info.n2        = ax25->n2;
		ax25_info.t1timer   = ax25_display_timer(&ax25->t1timer)   / HZ;
		ax25_info.t2timer   = ax25_display_timer(&ax25->t2timer)   / HZ;
		ax25_info.t3timer   = ax25_display_timer(&ax25->t3timer)   / HZ;
		ax25_info.idletimer = ax25_display_timer(&ax25->idletimer) / (60 * HZ);
		ax25_info.n2count   = ax25->n2count;
		ax25_info.state     = ax25->state;
		ax25_info.rcv_q     = atomic_read(&sk->sk_rmem_alloc);
		ax25_info.snd_q     = atomic_read(&sk->sk_wmem_alloc);
		ax25_info.vs        = ax25->vs;
		ax25_info.vr        = ax25->vr;
		ax25_info.va        = ax25->va;
		ax25_info.vs_max    = ax25->vs; /* reserved */
		ax25_info.paclen    = ax25->paclen;
		ax25_info.window    = ax25->window;

		/* old structure? */
		if (cmd == SIOCAX25GETINFOOLD) {
			static int warned = 0;
			if (!warned) {
				printk(KERN_INFO "%s uses old SIOCAX25GETINFO\n",
					current->comm);
				warned=1;
			}

			if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct_deprecated))) {
				res = -EFAULT;
				break;
			}
		} else {
			if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct))) {
				res = -EINVAL;
				break;
			}
		}
		res = 0;
		break;
	}

	case SIOCAX25ADDFWD:
	case SIOCAX25DELFWD: {
		struct ax25_fwd_struct ax25_fwd;
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		if (copy_from_user(&ax25_fwd, argp, sizeof(ax25_fwd))) {
			res = -EFAULT;
			break;
		}
		res = ax25_fwd_ioctl(cmd, &ax25_fwd);
		break;
	}

	case SIOCGIFADDR:
	case SIOCSIFADDR:
	case SIOCGIFDSTADDR:
	case SIOCSIFDSTADDR:
	case SIOCGIFBRDADDR:
	case SIOCSIFBRDADDR:
	case SIOCGIFNETMASK:
	case SIOCSIFNETMASK:
	case SIOCGIFMETRIC:
	case SIOCSIFMETRIC:
		res = -EINVAL;
		break;

	default:
		res = -ENOIOCTLCMD;
		break;
	}
	release_sock(sk);

	return res;
}

#ifdef CONFIG_PROC_FS

static void *ax25_info_start(struct seq_file *seq, loff_t *pos)
{
	struct ax25_cb *ax25;
	struct hlist_node *node;
	int i = 0;

	spin_lock_bh(&ax25_list_lock);
	ax25_for_each(ax25, node, &ax25_list) {
		if (i == *pos)
			return ax25;
		++i;
	}
	return NULL;
}

static void *ax25_info_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;

	return hlist_entry( ((struct ax25_cb *)v)->ax25_node.next,
			    struct ax25_cb, ax25_node);
}

static void ax25_info_stop(struct seq_file *seq, void *v)
{
	spin_unlock_bh(&ax25_list_lock);
}

static int ax25_info_show(struct seq_file *seq, void *v)
{
	ax25_cb *ax25 = v;
	char buf[11];
	int k;


	/*
	 * New format:
	 * magic dev src_addr dest_addr,digi1,digi2,.. st vs vr va t1 t1 t2 t2 t3 t3 idle idle n2 n2 rtt window paclen Snd-Q Rcv-Q inode
	 */

	seq_printf(seq, "%8.8lx %s %s%s ",
		   (long) ax25,
		   ax25->ax25_dev == NULL? "???" : ax25->ax25_dev->dev->name,
		   ax2asc(buf, &ax25->source_addr),
		   ax25->iamdigi? "*":"");
	seq_printf(seq, "%s", ax2asc(buf, &ax25->dest_addr));

	for (k=0; (ax25->digipeat != NULL) && (k < ax25->digipeat->ndigi); k++) {
		seq_printf(seq, ",%s%s",
			   ax2asc(buf, &ax25->digipeat->calls[k]),
			   ax25->digipeat->repeated[k]? "*":"");
	}

	seq_printf(seq, " %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %d %d",
		   ax25->state,
		   ax25->vs, ax25->vr, ax25->va,
		   ax25_display_timer(&ax25->t1timer) / HZ, ax25->t1 / HZ,
		   ax25_display_timer(&ax25->t2timer) / HZ, ax25->t2 / HZ,
		   ax25_display_timer(&ax25->t3timer) / HZ, ax25->t3 / HZ,
		   ax25_display_timer(&ax25->idletimer) / (60 * HZ),
		   ax25->idle / (60 * HZ),
		   ax25->n2count, ax25->n2,
		   ax25->rtt / HZ,
		   ax25->window,
		   ax25->paclen);

	if (ax25->sk != NULL) {
		bh_lock_sock(ax25->sk);
		seq_printf(seq," %d %d %ld\n",
			   atomic_read(&ax25->sk->sk_wmem_alloc),
			   atomic_read(&ax25->sk->sk_rmem_alloc),
			   ax25->sk->sk_socket != NULL ? SOCK_INODE(ax25->sk->sk_socket)->i_ino : 0L);
		bh_unlock_sock(ax25->sk);
	} else {
		seq_puts(seq, " * * *\n");
	}
	return 0;
}

static const struct seq_operations ax25_info_seqops = {
	.start = ax25_info_start,
	.next = ax25_info_next,
	.stop = ax25_info_stop,
	.show = ax25_info_show,
};

static int ax25_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ax25_info_seqops);
}

static const struct file_operations ax25_info_fops = {
	.owner = THIS_MODULE,
	.open = ax25_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

#endif

static struct net_proto_family ax25_family_ops = {
	.family =	PF_AX25,
	.create =	ax25_create,
	.owner	=	THIS_MODULE,
};

static const struct proto_ops ax25_proto_ops = {
	.family		= PF_AX25,
	.owner		= THIS_MODULE,
	.release	= ax25_release,
	.bind		= ax25_bind,
	.connect	= ax25_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= ax25_accept,
	.getname	= ax25_getname,
	.poll		= datagram_poll,
	.ioctl		= ax25_ioctl,
	.listen		= ax25_listen,
	.shutdown	= ax25_shutdown,
	.setsockopt	= ax25_setsockopt,
	.getsockopt	= ax25_getsockopt,
	.sendmsg	= ax25_sendmsg,
	.recvmsg	= ax25_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

/*
 *	Called by socket.c on kernel start up
 */
static struct packet_type ax25_packet_type = {
	.type	=	__constant_htons(ETH_P_AX25),
	.dev	=	NULL,				/* All devices */
	.func	=	ax25_kiss_rcv,
};

static struct notifier_block ax25_dev_notifier = {
	.notifier_call =ax25_device_event,
};

static int __init ax25_init(void)
{
	int rc = proto_register(&ax25_proto, 0);

	if (rc != 0)
		goto out;

	sock_register(&ax25_family_ops);
	dev_add_pack(&ax25_packet_type);
	register_netdevice_notifier(&ax25_dev_notifier);
	ax25_register_sysctl();

	proc_net_fops_create(&init_net, "ax25_route", S_IRUGO, &ax25_route_fops);
	proc_net_fops_create(&init_net, "ax25", S_IRUGO, &ax25_info_fops);
	proc_net_fops_create(&init_net, "ax25_calls", S_IRUGO, &ax25_uid_fops);
out:
	return rc;
}
module_init(ax25_init);


MODULE_AUTHOR("Jonathan Naylor G4KLX <[e-mail]>");
MODULE_DESCRIPTION("The amateur radio AX.25 link layer protocol");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_AX25);

static void __exit ax25_exit(void)
{
	proc_net_remove(&init_net, "ax25_route");
	proc_net_remove(&init_net, "ax25");
	proc_net_remove(&init_net, "ax25_calls");
	ax25_rt_free();
	ax25_uid_free();
	ax25_dev_free();

	ax25_unregister_sysctl();
	unregister_netdevice_notifier(&ax25_dev_notifier);

	dev_remove_pack(&ax25_packet_type);

	sock_unregister(PF_AX25);
	proto_unregister(&ax25_proto);
}
module_exit(ax25_exit);