1 files changed, 540 insertions, 0 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
new file mode 100644
index 000000000..2b582da1e
--- /dev/null
+++ b/net/phonet/af_phonet.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * File: af_phonet.c
+ *
+ * Phonet protocols family
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Authors: Sakari Ailus <sakari.ailus@nokia.com>
+ *          Rémi Denis-Courmont
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include <net/sock.h>
+
+#include <linux/if_phonet.h>
+#include <linux/phonet.h>
+#include <net/phonet/phonet.h>
+#include <net/phonet/pn_dev.h>
+
+/* Transport protocol registration */
+static const struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
+
+static const struct phonet_protocol *phonet_proto_get(unsigned int protocol)
+{
+	const struct phonet_protocol *pp;
+
+	if (protocol >= PHONET_NPROTO)
+		return NULL;
+
+	rcu_read_lock();
+	pp = rcu_dereference(proto_tab[protocol]);
+	if (pp && !try_module_get(pp->prot->owner))
+		pp = NULL;
+	rcu_read_unlock();
+
+	return pp;
+}
+
+static inline void phonet_proto_put(const struct phonet_protocol *pp)
+{
+	module_put(pp->prot->owner);
+}
+
+/* protocol family functions */
+
+static int pn_socket_create(struct net *net, struct socket *sock, int protocol,
+			    int kern)
+{
+	struct sock *sk;
+	struct pn_sock *pn;
+	const struct phonet_protocol *pnp;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (protocol == 0) {
+		/* Default protocol selection */
+		switch (sock->type) {
+		case SOCK_DGRAM:
+			protocol = PN_PROTO_PHONET;
+			break;
+		case SOCK_SEQPACKET:
+			protocol = PN_PROTO_PIPE;
+			break;
+		default:
+			return -EPROTONOSUPPORT;
+		}
+	}
+
+	pnp = phonet_proto_get(protocol);
+	if (pnp == NULL &&
+	    request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
+		pnp = phonet_proto_get(protocol);
+
+	if (pnp == NULL)
+		return -EPROTONOSUPPORT;
+	if (sock->type != pnp->sock_type) {
+		err = -EPROTONOSUPPORT;
+		goto out;
+	}
+
+	sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot, kern);
+	if (sk == NULL) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	sock_init_data(sock, sk);
+	sock->state = SS_UNCONNECTED;
+	sock->ops = pnp->ops;
+	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
+	sk->sk_protocol = protocol;
+	pn = pn_sk(sk);
+	pn->sobject = 0;
+	pn->dobject = 0;
+	pn->resource = 0;
+	sk->sk_prot->init(sk);
+	err = 0;
+
+out:
+	phonet_proto_put(pnp);
+	return err;
+}
+
+static const struct net_proto_family phonet_proto_family = {
+	.family = PF_PHONET,
+	.create = pn_socket_create,
+	.owner = THIS_MODULE,
+};
+
+/* Phonet device header operations */
+static int pn_header_create(struct sk_buff *skb, struct net_device *dev,
+				unsigned short type, const void *daddr,
+				const void *saddr, unsigned int len)
+{
+	u8 *media = skb_push(skb, 1);
+
+	if (type != ETH_P_PHONET)
+		return -1;
+
+	if (!saddr)
+		saddr = dev->dev_addr;
+	*media = *(const u8 *)saddr;
+	return 1;
+}
+
+static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+	const u8 *media = skb_mac_header(skb);
+	*haddr = *media;
+	return 1;
+}
+
+const struct header_ops phonet_header_ops = {
+	.create = pn_header_create,
+	.parse = pn_header_parse,
+};
+EXPORT_SYMBOL(phonet_header_ops);
+
+/*
+ * Prepends an ISI header and sends a datagram.
+ */
+static int pn_send(struct sk_buff *skb, struct net_device *dev,
+			u16 dst, u16 src, u8 res)
+{
+	struct phonethdr *ph;
+	int err;
+
+	if (skb->len + 2 > 0xffff /* Phonet length field limit */ ||
+	    skb->len + sizeof(struct phonethdr) > dev->mtu) {
+		err = -EMSGSIZE;
+		goto drop;
+	}
+
+	/* Broadcast sending is not implemented */
+	if (pn_addr(dst) == PNADDR_BROADCAST) {
+		err = -EOPNOTSUPP;
+		goto drop;
+	}
+
+	skb_reset_transport_header(skb);
+	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
+	skb_push(skb, sizeof(struct phonethdr));
+	skb_reset_network_header(skb);
+	ph = pn_hdr(skb);
+	ph->pn_rdev = pn_dev(dst);
+	ph->pn_sdev = pn_dev(src);
+	ph->pn_res = res;
+	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
+	ph->pn_robj = pn_obj(dst);
+	ph->pn_sobj = pn_obj(src);
+
+	skb->protocol = htons(ETH_P_PHONET);
+	skb->priority = 0;
+	skb->dev = dev;
+
+	if (skb->pkt_type == PACKET_LOOPBACK) {
+		skb_reset_mac_header(skb);
+		skb_orphan(skb);
+		err = netif_rx(skb) ? -ENOBUFS : 0;
+	} else {
+		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+					NULL, NULL, skb->len);
+		if (err < 0) {
+			err = -EHOSTUNREACH;
+			goto drop;
+		}
+		err = dev_queue_xmit(skb);
+		if (unlikely(err > 0))
+			err = net_xmit_errno(err);
+	}
+
+	return err;
+drop:
+	kfree_skb(skb);
+	return err;
+}
+
+static int pn_raw_send(const void *data, int len, struct net_device *dev,
+			u16 dst, u16 src, u8 res)
+{
+	struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
+	if (skb == NULL)
+		return -ENOMEM;
+
+	if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
+		skb->pkt_type = PACKET_LOOPBACK;
+
+	skb_reserve(skb, MAX_PHONET_HEADER);
+	__skb_put(skb, len);
+	skb_copy_to_linear_data(skb, data, len);
+	return pn_send(skb, dev, dst, src, res);
+}
+
+/*
+ * Create a Phonet header for the skb and send it out. Returns
+ * non-zero error code if failed. The skb is freed then.
+ */
+int pn_skb_send(struct sock *sk, struct sk_buff *skb,
+		const struct sockaddr_pn *target)
+{
+	struct net *net = sock_net(sk);
+	struct net_device *dev;
+	struct pn_sock *pn = pn_sk(sk);
+	int err;
+	u16 src, dst;
+	u8 daddr, saddr, res;
+
+	src = pn->sobject;
+	if (target != NULL) {
+		dst = pn_sockaddr_get_object(target);
+		res = pn_sockaddr_get_resource(target);
+	} else {
+		dst = pn->dobject;
+		res = pn->resource;
+	}
+	daddr = pn_addr(dst);
+
+	err = -EHOSTUNREACH;
+	if (sk->sk_bound_dev_if)
+		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
+	else if (phonet_address_lookup(net, daddr) == 0) {
+		dev = phonet_device_get(net);
+		skb->pkt_type = PACKET_LOOPBACK;
+	} else if (dst == 0) {
+		/* Resource routing (small race until phonet_rcv()) */
+		struct sock *sk = pn_find_sock_by_res(net, res);
+		if (sk)	{
+			sock_put(sk);
+			dev = phonet_device_get(net);
+			skb->pkt_type = PACKET_LOOPBACK;
+		} else
+			dev = phonet_route_output(net, daddr);
+	} else
+		dev = phonet_route_output(net, daddr);
+
+	if (!dev || !(dev->flags & IFF_UP))
+		goto drop;
+
+	saddr = phonet_address_get(dev, daddr);
+	if (saddr == PN_NO_ADDR)
+		goto drop;
+
+	if (!pn_addr(src))
+		src = pn_object(saddr, pn_obj(src));
+
+	err = pn_send(skb, dev, dst, src, res);
+	dev_put(dev);
+	return err;
+
+drop:
+	kfree_skb(skb);
+	dev_put(dev);
+	return err;
+}
+EXPORT_SYMBOL(pn_skb_send);
+
+/* Do not send an error message in response to an error message */
+static inline int can_respond(struct sk_buff *skb)
+{
+	const struct phonethdr *ph;
+	const struct phonetmsg *pm;
+	u8 submsg_id;
+
+	if (!pskb_may_pull(skb, 3))
+		return 0;
+
+	ph = pn_hdr(skb);
+	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
+		return 0;
+	if (ph->pn_res == PN_COMMGR) /* indications */
+		return 0;
+
+	ph = pn_hdr(skb); /* re-acquires the pointer */
+	pm = pn_msg(skb);
+	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
+		return 1;
+	submsg_id = (ph->pn_res == PN_PREFIX)
+		? pm->pn_e_submsg_id : pm->pn_submsg_id;
+	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
+		pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
+		return 1;
+	return 0;
+}
+
+static int send_obj_unreachable(struct sk_buff *rskb)
+{
+	const struct phonethdr *oph = pn_hdr(rskb);
+	const struct phonetmsg *opm = pn_msg(rskb);
+	struct phonetmsg resp;
+
+	memset(&resp, 0, sizeof(resp));
+	resp.pn_trans_id = opm->pn_trans_id;
+	resp.pn_msg_id = PN_COMMON_MESSAGE;
+	if (oph->pn_res == PN_PREFIX) {
+		resp.pn_e_res_id = opm->pn_e_res_id;
+		resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
+		resp.pn_e_orig_msg_id = opm->pn_msg_id;
+		resp.pn_e_status = 0;
+	} else {
+		resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
+		resp.pn_orig_msg_id = opm->pn_msg_id;
+		resp.pn_status = 0;
+	}
+	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
+				pn_object(oph->pn_sdev, oph->pn_sobj),
+				pn_object(oph->pn_rdev, oph->pn_robj),
+				oph->pn_res);
+}
+
+static int send_reset_indications(struct sk_buff *rskb)
+{
+	struct phonethdr *oph = pn_hdr(rskb);
+	static const u8 data[4] = {
+		0x00 /* trans ID */, 0x10 /* subscribe msg */,
+		0x00 /* subscription count */, 0x00 /* dummy */
+	};
+
+	return pn_raw_send(data, sizeof(data), rskb->dev,
+				pn_object(oph->pn_sdev, 0x00),
+				pn_object(oph->pn_rdev, oph->pn_robj),
+				PN_COMMGR);
+}
+
+
+/* packet type functions */
+
+/*
+ * Stuff received packets to associated sockets.
+ * On error, returns non-zero and releases the skb.
+ */
+static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
+			struct packet_type *pkttype,
+			struct net_device *orig_dev)
+{
+	struct net *net = dev_net(dev);
+	struct phonethdr *ph;
+	struct sockaddr_pn sa;
+	u16 len;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		return NET_RX_DROP;
+
+	/* check we have at least a full Phonet header */
+	if (!pskb_pull(skb, sizeof(struct phonethdr)))
+		goto out;
+
+	/* check that the advertised length is correct */
+	ph = pn_hdr(skb);
+	len = get_unaligned_be16(&ph->pn_length);
+	if (len < 2)
+		goto out;
+	len -= 2;
+	if ((len > skb->len) || pskb_trim(skb, len))
+		goto out;
+	skb_reset_transport_header(skb);
+
+	pn_skb_get_dst_sockaddr(skb, &sa);
+
+	/* check if this is broadcasted */
+	if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
+		pn_deliver_sock_broadcast(net, skb);
+		goto out;
+	}
+
+	/* resource routing */
+	if (pn_sockaddr_get_object(&sa) == 0) {
+		struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource);
+		if (sk)
+			return sk_receive_skb(sk, skb, 0);
+	}
+
+	/* check if we are the destination */
+	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
+		/* Phonet packet input */
+		struct sock *sk = pn_find_sock_by_sa(net, &sa);
+
+		if (sk)
+			return sk_receive_skb(sk, skb, 0);
+
+		if (can_respond(skb)) {
+			send_obj_unreachable(skb);
+			send_reset_indications(skb);
+		}
+	} else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
+		goto out; /* Race between address deletion and loopback */
+	else {
+		/* Phonet packet routing */
+		struct net_device *out_dev;
+
+		out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
+		if (!out_dev) {
+			net_dbg_ratelimited("No Phonet route to %02X\n",
+					    pn_sockaddr_get_addr(&sa));
+			goto out;
+		}
+
+		__skb_push(skb, sizeof(struct phonethdr));
+		skb->dev = out_dev;
+		if (out_dev == dev) {
+			net_dbg_ratelimited("Phonet loop to %02X on %s\n",
+					    pn_sockaddr_get_addr(&sa),
+					    dev->name);
+			goto out_dev;
+		}
+		/* Some drivers (e.g. TUN) do not allocate HW header space */
+		if (skb_cow_head(skb, out_dev->hard_header_len))
+			goto out_dev;
+
+		if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
+					skb->len) < 0)
+			goto out_dev;
+		dev_queue_xmit(skb);
+		dev_put(out_dev);
+		return NET_RX_SUCCESS;
+out_dev:
+		dev_put(out_dev);
+	}
+
+out:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static struct packet_type phonet_packet_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_PHONET),
+	.func = phonet_rcv,
+};
+
+static DEFINE_MUTEX(proto_tab_lock);
+
+int __init_or_module phonet_proto_register(unsigned int protocol,
+				const struct phonet_protocol *pp)
+{
+	int err = 0;
+
+	if (protocol >= PHONET_NPROTO)
+		return -EINVAL;
+
+	err = proto_register(pp->prot, 1);
+	if (err)
+		return err;
+
+	mutex_lock(&proto_tab_lock);
+	if (proto_tab[protocol])
+		err = -EBUSY;
+	else
+		rcu_assign_pointer(proto_tab[protocol], pp);
+	mutex_unlock(&proto_tab_lock);
+
+	return err;
+}
+EXPORT_SYMBOL(phonet_proto_register);
+
+void phonet_proto_unregister(unsigned int protocol,
+			const struct phonet_protocol *pp)
+{
+	mutex_lock(&proto_tab_lock);
+	BUG_ON(proto_tab[protocol] != pp);
+	RCU_INIT_POINTER(proto_tab[protocol], NULL);
+	mutex_unlock(&proto_tab_lock);
+	synchronize_rcu();
+	proto_unregister(pp->prot);
+}
+EXPORT_SYMBOL(phonet_proto_unregister);
+
+/* Module registration */
+static int __init phonet_init(void)
+{
+	int err;
+
+	err = phonet_device_init();
+	if (err)
+		return err;
+
+	pn_sock_init();
+	err = sock_register(&phonet_proto_family);
+	if (err) {
+		printk(KERN_ALERT
+			"phonet protocol family initialization failed\n");
+		goto err_sock;
+	}
+
+	dev_add_pack(&phonet_packet_type);
+	phonet_sysctl_init();
+
+	err = isi_register();
+	if (err)
+		goto err;
+	return 0;
+
+err:
+	phonet_sysctl_exit();
+	sock_unregister(PF_PHONET);
+	dev_remove_pack(&phonet_packet_type);
+err_sock:
+	phonet_device_exit();
+	return err;
+}
+
+static void __exit phonet_exit(void)
+{
+	isi_unregister();
+	phonet_sysctl_exit();
+	sock_unregister(PF_PHONET);
+	dev_remove_pack(&phonet_packet_type);
+	phonet_device_exit();
+}
+
+module_init(phonet_init);
+module_exit(phonet_exit);
+MODULE_DESCRIPTION("Phonet protocol stack for Linux");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_PHONET);