ieee802154: 6lowpan: move receive functionality

This patch moves all relevant receive functionality into a separate rx.c
file. We can simple separate this functionality like we did it in mac802154.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c
new file mode 100644
index 000000000000..4be1d289ab2d
--- /dev/null
+++ b/net/ieee802154/6lowpan/rx.c
@@ -0,0 +1,171 @@
+/* This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/if_arp.h>
+
+#include <net/6lowpan.h>
+#include <net/ieee802154_netdev.h>
+
+#include "6lowpan_i.h"
+
+static int lowpan_give_skb_to_devices(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	struct lowpan_dev_record *entry;
+	struct sk_buff *skb_cp;
+	int stat = NET_RX_SUCCESS;
+
+	skb->protocol = htons(ETH_P_IPV6);
+	skb->pkt_type = PACKET_HOST;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &lowpan_devices, list)
+		if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
+			skb_cp = skb_copy(skb, GFP_ATOMIC);
+			if (!skb_cp) {
+				kfree_skb(skb);
+				rcu_read_unlock();
+				return NET_RX_DROP;
+			}
+
+			skb_cp->dev = entry->ldev;
+			stat = netif_rx(skb_cp);
+			if (stat == NET_RX_DROP)
+				break;
+		}
+	rcu_read_unlock();
+
+	consume_skb(skb);
+
+	return stat;
+}
+
+static int
+iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
+{
+	u8 iphc0, iphc1;
+	struct ieee802154_addr_sa sa, da;
+	void *sap, *dap;
+
+	raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
+	/* at least two bytes will be used for the encoding */
+	if (skb->len < 2)
+		return -EINVAL;
+
+	if (lowpan_fetch_skb_u8(skb, &iphc0))
+		return -EINVAL;
+
+	if (lowpan_fetch_skb_u8(skb, &iphc1))
+		return -EINVAL;
+
+	ieee802154_addr_to_sa(&sa, &hdr->source);
+	ieee802154_addr_to_sa(&da, &hdr->dest);
+
+	if (sa.addr_type == IEEE802154_ADDR_SHORT)
+		sap = &sa.short_addr;
+	else
+		sap = &sa.hwaddr;
+
+	if (da.addr_type == IEEE802154_ADDR_SHORT)
+		dap = &da.short_addr;
+	else
+		dap = &da.hwaddr;
+
+	return lowpan_header_decompress(skb, skb->dev, sap, sa.addr_type,
+					IEEE802154_ADDR_LEN, dap, da.addr_type,
+					IEEE802154_ADDR_LEN, iphc0, iphc1);
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
+		      struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct ieee802154_hdr hdr;
+	int ret;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto drop;
+
+	if (!netif_running(dev))
+		goto drop_skb;
+
+	if (skb->pkt_type == PACKET_OTHERHOST)
+		goto drop_skb;
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto drop_skb;
+
+	if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
+		goto drop_skb;
+
+	/* check that it's our buffer */
+	if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
+		/* Pull off the 1-byte of 6lowpan header. */
+		skb_pull(skb, 1);
+		return lowpan_give_skb_to_devices(skb, NULL);
+	} else {
+		switch (skb->data[0] & 0xe0) {
+		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
+			ret = iphc_decompress(skb, &hdr);
+			if (ret < 0)
+				goto drop_skb;
+
+			return lowpan_give_skb_to_devices(skb, NULL);
+		case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
+			ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
+			if (ret == 1) {
+				ret = iphc_decompress(skb, &hdr);
+				if (ret < 0)
+					goto drop_skb;
+
+				return lowpan_give_skb_to_devices(skb, NULL);
+			} else if (ret == -1) {
+				return NET_RX_DROP;
+			} else {
+				return NET_RX_SUCCESS;
+			}
+		case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
+			ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
+			if (ret == 1) {
+				ret = iphc_decompress(skb, &hdr);
+				if (ret < 0)
+					goto drop_skb;
+
+				return lowpan_give_skb_to_devices(skb, NULL);
+			} else if (ret == -1) {
+				return NET_RX_DROP;
+			} else {
+				return NET_RX_SUCCESS;
+			}
+		default:
+			break;
+		}
+	}
+
+drop_skb:
+	kfree_skb(skb);
+drop:
+	return NET_RX_DROP;
+}
+
+static struct packet_type lowpan_packet_type = {
+	.type = htons(ETH_P_IEEE802154),
+	.func = lowpan_rcv,
+};
+
+void lowpan_rx_init(void)
+{
+	dev_add_pack(&lowpan_packet_type);
+}
+
+void lowpan_rx_exit(void)
+{
+	dev_remove_pack(&lowpan_packet_type);
+}