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-rw-r--r--net/6lowpan/Kconfig57
-rw-r--r--net/6lowpan/Makefile13
-rw-r--r--net/6lowpan/iphc.c200
-rw-r--r--net/6lowpan/nhc.c241
-rw-r--r--net/6lowpan/nhc.h146
-rw-r--r--net/6lowpan/nhc_dest.c28
-rw-r--r--net/6lowpan/nhc_fragment.c27
-rw-r--r--net/6lowpan/nhc_hop.c27
-rw-r--r--net/6lowpan/nhc_ipv6.c27
-rw-r--r--net/6lowpan/nhc_mobility.c27
-rw-r--r--net/6lowpan/nhc_routing.c27
-rw-r--r--net/6lowpan/nhc_udp.c157
12 files changed, 806 insertions, 171 deletions
diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig
index e4a02ef55102..7fa0f382e7d1 100644
--- a/net/6lowpan/Kconfig
+++ b/net/6lowpan/Kconfig
@@ -1,6 +1,61 @@
-config 6LOWPAN
+menuconfig 6LOWPAN
 	tristate "6LoWPAN Support"
 	depends on IPV6
 	---help---
 	  This enables IPv6 over Low power Wireless Personal Area Network -
 	  "6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks.
+
+menuconfig 6LOWPAN_NHC
+	tristate "Next Header Compression Support"
+	depends on 6LOWPAN
+	default y
+	---help---
+	  Support for next header compression.
+
+if 6LOWPAN_NHC
+
+config 6LOWPAN_NHC_DEST
+	tristate "Destination Options Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Destination Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_FRAGMENT
+	tristate "Fragment Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Fragment Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_HOP
+	tristate "Hop-by-Hop Options Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Hop-by-Hop Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_IPV6
+	tristate "IPv6 Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_MOBILITY
+	tristate "Mobility Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Mobility Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_ROUTING
+	tristate "Routing Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Routing Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_UDP
+	tristate "UDP Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 UDP Header compression according to RFC6282.
+
+endif
diff --git a/net/6lowpan/Makefile b/net/6lowpan/Makefile
index 415886bb456a..eb8baa72adc8 100644
--- a/net/6lowpan/Makefile
+++ b/net/6lowpan/Makefile
@@ -1,3 +1,12 @@
-obj-$(CONFIG_6LOWPAN) := 6lowpan.o
+obj-$(CONFIG_6LOWPAN) += 6lowpan.o
 
-6lowpan-y := iphc.o
+6lowpan-y := iphc.o nhc.o
+
+#rfc6282 nhcs
+obj-$(CONFIG_6LOWPAN_NHC_DEST) += nhc_dest.o
+obj-$(CONFIG_6LOWPAN_NHC_FRAGMENT) += nhc_fragment.o
+obj-$(CONFIG_6LOWPAN_NHC_HOP) += nhc_hop.o
+obj-$(CONFIG_6LOWPAN_NHC_IPV6) += nhc_ipv6.o
+obj-$(CONFIG_6LOWPAN_NHC_MOBILITY) += nhc_mobility.o
+obj-$(CONFIG_6LOWPAN_NHC_ROUTING) += nhc_routing.o
+obj-$(CONFIG_6LOWPAN_NHC_UDP) += nhc_udp.o
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index 32ffec6ef164..94a375c04f21 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -54,6 +54,8 @@
 #include <net/ipv6.h>
 #include <net/af_ieee802154.h>
 
+#include "nhc.h"
+
 /* Uncompress address function for source and
  * destination address(non-multicast).
  *
@@ -224,77 +226,6 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
 	return 0;
 }
 
-static int uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
-{
-	bool fail;
-	u8 tmp = 0, val = 0;
-
-	fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp));
-
-	if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
-		pr_debug("UDP header uncompression\n");
-		switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
-		case LOWPAN_NHC_UDP_CS_P_00:
-			fail |= lowpan_fetch_skb(skb, &uh->source,
-						 sizeof(uh->source));
-			fail |= lowpan_fetch_skb(skb, &uh->dest,
-						 sizeof(uh->dest));
-			break;
-		case LOWPAN_NHC_UDP_CS_P_01:
-			fail |= lowpan_fetch_skb(skb, &uh->source,
-						 sizeof(uh->source));
-			fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
-			uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
-			break;
-		case LOWPAN_NHC_UDP_CS_P_10:
-			fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
-			uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
-			fail |= lowpan_fetch_skb(skb, &uh->dest,
-						 sizeof(uh->dest));
-			break;
-		case LOWPAN_NHC_UDP_CS_P_11:
-			fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
-			uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT +
-					   (val >> 4));
-			uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT +
-					 (val & 0x0f));
-			break;
-		default:
-			pr_debug("ERROR: unknown UDP format\n");
-			goto err;
-		}
-
-		pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
-			 ntohs(uh->source), ntohs(uh->dest));
-
-		/* checksum */
-		if (tmp & LOWPAN_NHC_UDP_CS_C) {
-			pr_debug_ratelimited("checksum elided currently not supported\n");
-			goto err;
-		} else {
-			fail |= lowpan_fetch_skb(skb, &uh->check,
-						 sizeof(uh->check));
-		}
-
-		/* UDP length needs to be infered from the lower layers
-		 * here, we obtain the hint from the remaining size of the
-		 * frame
-		 */
-		uh->len = htons(skb->len + sizeof(struct udphdr));
-		pr_debug("uncompressed UDP length: src = %d", ntohs(uh->len));
-	} else {
-		pr_debug("ERROR: unsupported NH format\n");
-		goto err;
-	}
-
-	if (fail)
-		goto err;
-
-	return 0;
-err:
-	return -EINVAL;
-}
-
 /* TTL uncompression values */
 static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
 
@@ -425,29 +356,11 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
 			return -EINVAL;
 	}
 
-	/* UDP data uncompression */
+	/* Next header data uncompression */
 	if (iphc0 & LOWPAN_IPHC_NH_C) {
-		struct udphdr uh;
-		const int needed = sizeof(struct udphdr) + sizeof(hdr);
-
-		if (uncompress_udp_header(skb, &uh))
-			return -EINVAL;
-
-		/* replace the compressed UDP head by the uncompressed UDP
-		 * header
-		 */
-		err = skb_cow(skb, needed);
-		if (unlikely(err))
+		err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
+		if (err < 0)
 			return err;
-
-		skb_push(skb, sizeof(struct udphdr));
-		skb_reset_transport_header(skb);
-		skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
-
-		raw_dump_table(__func__, "raw UDP header dump",
-			       (u8 *)&uh, sizeof(uh));
-
-		hdr.nexthdr = UIP_PROTO_UDP;
 	} else {
 		err = skb_cow(skb, sizeof(hdr));
 		if (unlikely(err))
@@ -500,71 +413,6 @@ static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
 	return rol8(val, shift);
 }
 
-static void compress_udp_header(u8 **hc_ptr, struct sk_buff *skb)
-{
-	struct udphdr *uh;
-	u8 tmp;
-
-	/* In the case of RAW sockets the transport header is not set by
-	 * the ip6 stack so we must set it ourselves
-	 */
-	if (skb->transport_header == skb->network_header)
-		skb_set_transport_header(skb, sizeof(struct ipv6hdr));
-
-	uh = udp_hdr(skb);
-
-	if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) ==
-	     LOWPAN_NHC_UDP_4BIT_PORT) &&
-	    ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) ==
-	     LOWPAN_NHC_UDP_4BIT_PORT)) {
-		pr_debug("UDP header: both ports compression to 4 bits\n");
-		/* compression value */
-		tmp = LOWPAN_NHC_UDP_CS_P_11;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-		/* source and destination port */
-		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
-		      ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-	} else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
-			LOWPAN_NHC_UDP_8BIT_PORT) {
-		pr_debug("UDP header: remove 8 bits of dest\n");
-		/* compression value */
-		tmp = LOWPAN_NHC_UDP_CS_P_01;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-		/* source port */
-		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
-		/* destination port */
-		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-	} else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
-			LOWPAN_NHC_UDP_8BIT_PORT) {
-		pr_debug("UDP header: remove 8 bits of source\n");
-		/* compression value */
-		tmp = LOWPAN_NHC_UDP_CS_P_10;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-		/* source port */
-		tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-		/* destination port */
-		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
-	} else {
-		pr_debug("UDP header: can't compress\n");
-		/* compression value */
-		tmp = LOWPAN_NHC_UDP_CS_P_00;
-		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
-		/* source port */
-		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
-		/* destination port */
-		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
-	}
-
-	/* checksum is always inline */
-	lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check));
-
-	/* skip the UDP header */
-	skb_pull(skb, sizeof(struct udphdr));
-}
-
 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 			   unsigned short type, const void *_daddr,
 			   const void *_saddr, unsigned int len)
@@ -572,7 +420,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 	u8 tmp, iphc0, iphc1, *hc_ptr;
 	struct ipv6hdr *hdr;
 	u8 head[100] = {};
-	int addr_type;
+	int ret, addr_type;
 
 	if (type != ETH_P_IPV6)
 		return -EINVAL;
@@ -649,13 +497,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 
 	/* NOTE: payload length is always compressed */
 
-	/* Next Header is compress if UDP */
-	if (hdr->nexthdr == UIP_PROTO_UDP)
-		iphc0 |= LOWPAN_IPHC_NH_C;
-
-	if ((iphc0 & LOWPAN_IPHC_NH_C) == 0)
-		lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
-				    sizeof(hdr->nexthdr));
+	/* Check if we provide the nhc format for nexthdr and compression
+	 * functionality. If not nexthdr is handled inline and not compressed.
+	 */
+	ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0);
+	if (ret < 0)
+		return ret;
 
 	/* Hop limit
 	 * if 1:   compress, encoding is 01
@@ -741,9 +588,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 		}
 	}
 
-	/* UDP header compression */
-	if (hdr->nexthdr == UIP_PROTO_UDP)
-		compress_udp_header(&hc_ptr, skb);
+	/* next header compression */
+	if (iphc0 & LOWPAN_IPHC_NH_C) {
+		ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
+		if (ret < 0)
+			return ret;
+	}
 
 	head[0] = iphc0;
 	head[1] = iphc1;
@@ -761,4 +611,18 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(lowpan_header_compress);
 
+static int __init lowpan_module_init(void)
+{
+	request_module_nowait("nhc_dest");
+	request_module_nowait("nhc_fragment");
+	request_module_nowait("nhc_hop");
+	request_module_nowait("nhc_ipv6");
+	request_module_nowait("nhc_mobility");
+	request_module_nowait("nhc_routing");
+	request_module_nowait("nhc_udp");
+
+	return 0;
+}
+module_init(lowpan_module_init);
+
 MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc.c b/net/6lowpan/nhc.c
new file mode 100644
index 000000000000..fd20fc51a7c4
--- /dev/null
+++ b/net/6lowpan/nhc.c
@@ -0,0 +1,241 @@
+/*
+ *	6LoWPAN next header compression
+ *
+ *
+ *	Authors:
+ *	Alexander Aring		<aar@pengutronix.de>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/netdevice.h>
+
+#include <net/ipv6.h>
+
+#include "nhc.h"
+
+static struct rb_root rb_root = RB_ROOT;
+static struct lowpan_nhc *lowpan_nexthdr_nhcs[NEXTHDR_MAX];
+static DEFINE_SPINLOCK(lowpan_nhc_lock);
+
+static int lowpan_nhc_insert(struct lowpan_nhc *nhc)
+{
+	struct rb_node **new = &rb_root.rb_node, *parent = NULL;
+
+	/* Figure out where to put new node */
+	while (*new) {
+		struct lowpan_nhc *this = container_of(*new, struct lowpan_nhc,
+						       node);
+		int result, len_dif, len;
+
+		len_dif = nhc->idlen - this->idlen;
+
+		if (nhc->idlen < this->idlen)
+			len = nhc->idlen;
+		else
+			len = this->idlen;
+
+		result = memcmp(nhc->id, this->id, len);
+		if (!result)
+			result = len_dif;
+
+		parent = *new;
+		if (result < 0)
+			new = &((*new)->rb_left);
+		else if (result > 0)
+			new = &((*new)->rb_right);
+		else
+			return -EEXIST;
+	}
+
+	/* Add new node and rebalance tree. */
+	rb_link_node(&nhc->node, parent, new);
+	rb_insert_color(&nhc->node, &rb_root);
+
+	return 0;
+}
+
+static void lowpan_nhc_remove(struct lowpan_nhc *nhc)
+{
+	rb_erase(&nhc->node, &rb_root);
+}
+
+static struct lowpan_nhc *lowpan_nhc_by_nhcid(const struct sk_buff *skb)
+{
+	struct rb_node *node = rb_root.rb_node;
+	const u8 *nhcid_skb_ptr = skb->data;
+
+	while (node) {
+		struct lowpan_nhc *nhc = container_of(node, struct lowpan_nhc,
+						      node);
+		u8 nhcid_skb_ptr_masked[LOWPAN_NHC_MAX_ID_LEN];
+		int result, i;
+
+		if (nhcid_skb_ptr + nhc->idlen > skb->data + skb->len)
+			return NULL;
+
+		/* copy and mask afterwards the nhid value from skb */
+		memcpy(nhcid_skb_ptr_masked, nhcid_skb_ptr, nhc->idlen);
+		for (i = 0; i < nhc->idlen; i++)
+			nhcid_skb_ptr_masked[i] &= nhc->idmask[i];
+
+		result = memcmp(nhcid_skb_ptr_masked, nhc->id, nhc->idlen);
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return nhc;
+	}
+
+	return NULL;
+}
+
+int lowpan_nhc_check_compression(struct sk_buff *skb,
+				 const struct ipv6hdr *hdr, u8 **hc_ptr,
+				 u8 *iphc0)
+{
+	struct lowpan_nhc *nhc;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nexthdr_nhcs[hdr->nexthdr];
+	if (nhc && nhc->compress)
+		*iphc0 |= LOWPAN_IPHC_NH_C;
+	else
+		lowpan_push_hc_data(hc_ptr, &hdr->nexthdr,
+				    sizeof(hdr->nexthdr));
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return 0;
+}
+
+int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
+			      u8 **hc_ptr)
+{
+	int ret;
+	struct lowpan_nhc *nhc;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nexthdr_nhcs[hdr->nexthdr];
+	/* check if the nhc module was removed in unlocked part.
+	 * TODO: this is a workaround we should prevent unloading
+	 * of nhc modules while unlocked part, this will always drop
+	 * the lowpan packet but it's very unlikely.
+	 *
+	 * Solution isn't easy because we need to decide at
+	 * lowpan_nhc_check_compression if we do a compression or not.
+	 * Because the inline data which is added to skb, we can't move this
+	 * handling.
+	 */
+	if (unlikely(!nhc || !nhc->compress)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* In the case of RAW sockets the transport header is not set by
+	 * the ip6 stack so we must set it ourselves
+	 */
+	if (skb->transport_header == skb->network_header)
+		skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+
+	ret = nhc->compress(skb, hc_ptr);
+	if (ret < 0)
+		goto out;
+
+	/* skip the transport header */
+	skb_pull(skb, nhc->nexthdrlen);
+
+out:
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return ret;
+}
+
+int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
+				struct ipv6hdr *hdr)
+{
+	struct lowpan_nhc *nhc;
+	int ret;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nhc_by_nhcid(skb);
+	if (nhc) {
+		if (nhc->uncompress) {
+			ret = nhc->uncompress(skb, sizeof(struct ipv6hdr) +
+					      nhc->nexthdrlen);
+			if (ret < 0) {
+				spin_unlock_bh(&lowpan_nhc_lock);
+				return ret;
+			}
+		} else {
+			spin_unlock_bh(&lowpan_nhc_lock);
+			netdev_warn(dev, "received nhc id for %s which is not implemented.\n",
+				    nhc->name);
+			return -ENOTSUPP;
+		}
+	} else {
+		spin_unlock_bh(&lowpan_nhc_lock);
+		netdev_warn(dev, "received unknown nhc id which was not found.\n");
+		return -ENOENT;
+	}
+
+	hdr->nexthdr = nhc->nexthdr;
+	skb_reset_transport_header(skb);
+	raw_dump_table(__func__, "raw transport header dump",
+		       skb_transport_header(skb), nhc->nexthdrlen);
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return 0;
+}
+
+int lowpan_nhc_add(struct lowpan_nhc *nhc)
+{
+	int ret;
+
+	if (!nhc->idlen || !nhc->idsetup)
+		return -EINVAL;
+
+	WARN_ONCE(nhc->idlen > LOWPAN_NHC_MAX_ID_LEN,
+		  "LOWPAN_NHC_MAX_ID_LEN should be updated to %zd.\n",
+		  nhc->idlen);
+
+	nhc->idsetup(nhc);
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	if (lowpan_nexthdr_nhcs[nhc->nexthdr]) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	ret = lowpan_nhc_insert(nhc);
+	if (ret < 0)
+		goto out;
+
+	lowpan_nexthdr_nhcs[nhc->nexthdr] = nhc;
+out:
+	spin_unlock_bh(&lowpan_nhc_lock);
+	return ret;
+}
+EXPORT_SYMBOL(lowpan_nhc_add);
+
+void lowpan_nhc_del(struct lowpan_nhc *nhc)
+{
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	lowpan_nhc_remove(nhc);
+	lowpan_nexthdr_nhcs[nhc->nexthdr] = NULL;
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(lowpan_nhc_del);
diff --git a/net/6lowpan/nhc.h b/net/6lowpan/nhc.h
new file mode 100644
index 000000000000..ed44938eb5de
--- /dev/null
+++ b/net/6lowpan/nhc.h
@@ -0,0 +1,146 @@
+#ifndef __6LOWPAN_NHC_H
+#define __6LOWPAN_NHC_H
+
+#include <linux/skbuff.h>
+#include <linux/rbtree.h>
+#include <linux/module.h>
+
+#include <net/6lowpan.h>
+#include <net/ipv6.h>
+
+#define LOWPAN_NHC_MAX_ID_LEN	1
+
+/**
+ * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct
+ *
+ * @__nhc: variable name of the lowpan_nhc struct.
+ * @_name: const char * of common header compression name.
+ * @_nexthdr: ipv6 nexthdr field for the header compression.
+ * @_nexthdrlen: ipv6 nexthdr len for the reserved space.
+ * @_idsetup: callback to setup id and mask values.
+ * @_idlen: len for the next header id and mask, should be always the same.
+ * @_uncompress: callback for uncompression call.
+ * @_compress: callback for compression call.
+ */
+#define LOWPAN_NHC(__nhc, _name, _nexthdr,	\
+		   _hdrlen, _idsetup, _idlen,	\
+		   _uncompress, _compress)	\
+static u8 __nhc##_val[_idlen];			\
+static u8 __nhc##_mask[_idlen];			\
+static struct lowpan_nhc __nhc = {		\
+	.name		= _name,		\
+	.nexthdr	= _nexthdr,		\
+	.nexthdrlen	= _hdrlen,		\
+	.id		= __nhc##_val,		\
+	.idmask		= __nhc##_mask,		\
+	.idlen		= _idlen,		\
+	.idsetup	= _idsetup,		\
+	.uncompress	= _uncompress,		\
+	.compress	= _compress,		\
+}
+
+#define module_lowpan_nhc(__nhc)		\
+static int __init __nhc##_init(void)		\
+{						\
+	return lowpan_nhc_add(&(__nhc));	\
+}						\
+module_init(__nhc##_init);			\
+static void __exit __nhc##_exit(void)		\
+{						\
+	lowpan_nhc_del(&(__nhc));		\
+}						\
+module_exit(__nhc##_exit);
+
+/**
+ * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation
+ *
+ * @node: holder for the rbtree.
+ * @name: name of the specific next header compression
+ * @nexthdr: next header value of the protocol which should be compressed.
+ * @nexthdrlen: ipv6 nexthdr len for the reserved space.
+ * @id: array for nhc id. Note this need to be in network byteorder.
+ * @mask: array for nhc id mask. Note this need to be in network byteorder.
+ * @len: the length of the next header id and mask.
+ * @setup: callback to setup fill the next header id value and mask.
+ * @compress: callback to do the header compression.
+ * @uncompress: callback to do the header uncompression.
+ */
+struct lowpan_nhc {
+	struct rb_node	node;
+	const char	*name;
+	const u8	nexthdr;
+	const size_t	nexthdrlen;
+	u8		*id;
+	u8		*idmask;
+	const size_t	idlen;
+
+	void		(*idsetup)(struct lowpan_nhc *nhc);
+	int		(*uncompress)(struct sk_buff *skb, size_t needed);
+	int		(*compress)(struct sk_buff *skb, u8 **hc_ptr);
+};
+
+/**
+ * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr.
+ *
+ * @nexthdr: ipv6 nexthdr value.
+ */
+struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr);
+
+/**
+ * lowpan_nhc_check_compression - checks if we support compression format. If
+ *	we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be
+ *	set. If we don't support nexthdr will be added as inline data to the
+ *	6LoWPAN header.
+ *
+ * @skb: skb of 6LoWPAN header to read nhc and replace header.
+ * @hdr: ipv6hdr to check the nexthdr value
+ * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
+ *	    replaced header.
+ * @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit
+ */
+int lowpan_nhc_check_compression(struct sk_buff *skb,
+				 const struct ipv6hdr *hdr, u8 **hc_ptr,
+				 u8 *iphc0);
+
+/**
+ * lowpan_nhc_do_compression - calling compress callback for nhc
+ *
+ * @skb: skb of 6LoWPAN header to read nhc and replace header.
+ * @hdr: ipv6hdr to set the nexthdr value
+ * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
+ *	    replaced header.
+ */
+int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
+			      u8 **hc_ptr);
+
+/**
+ * lowpan_nhc_do_uncompression - calling uncompress callback for nhc
+ *
+ * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions.
+ * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value.
+ * @dev: netdevice for print logging information.
+ * @hdr: ipv6hdr for setting nexthdr value.
+ */
+int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
+				struct ipv6hdr *hdr);
+
+/**
+ * lowpan_nhc_add - register a next header compression to framework
+ *
+ * @nhc: nhc which should be add.
+ */
+int lowpan_nhc_add(struct lowpan_nhc *nhc);
+
+/**
+ * lowpan_nhc_del - delete a next header compression from framework
+ *
+ * @nhc: nhc which should be delete.
+ */
+void lowpan_nhc_del(struct lowpan_nhc *nhc);
+
+/**
+ * lowpan_nhc_init - adding all default nhcs
+ */
+void lowpan_nhc_init(void);
+
+#endif /* __6LOWPAN_NHC_H */
diff --git a/net/6lowpan/nhc_dest.c b/net/6lowpan/nhc_dest.c
new file mode 100644
index 000000000000..0b292c9646eb
--- /dev/null
+++ b/net/6lowpan/nhc_dest.c
@@ -0,0 +1,28 @@
+/*
+ *	6LoWPAN IPv6 Destination Options Header compression according to
+ *	RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_DEST_IDLEN	1
+#define LOWPAN_NHC_DEST_ID_0	0xe6
+#define LOWPAN_NHC_DEST_MASK_0	0xfe
+
+static void dest_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_DEST_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_DEST_MASK_0;
+}
+
+LOWPAN_NHC(nhc_dest, "RFC6282 Destination Options", NEXTHDR_DEST, 0,
+	   dest_nhid_setup, LOWPAN_NHC_DEST_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_dest);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Destination Options compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_fragment.c b/net/6lowpan/nhc_fragment.c
new file mode 100644
index 000000000000..473dbc58ef84
--- /dev/null
+++ b/net/6lowpan/nhc_fragment.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Fragment Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_FRAGMENT_IDLEN	1
+#define LOWPAN_NHC_FRAGMENT_ID_0	0xe4
+#define LOWPAN_NHC_FRAGMENT_MASK_0	0xfe
+
+static void fragment_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_FRAGMENT_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_FRAGMENT_MASK_0;
+}
+
+LOWPAN_NHC(nhc_fragment, "RFC6282 Fragment", NEXTHDR_FRAGMENT, 0,
+	   fragment_nhid_setup, LOWPAN_NHC_FRAGMENT_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_fragment);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Fragment compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_hop.c b/net/6lowpan/nhc_hop.c
new file mode 100644
index 000000000000..1eb66be16f19
--- /dev/null
+++ b/net/6lowpan/nhc_hop.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Hop-by-Hop Options Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_HOP_IDLEN	1
+#define LOWPAN_NHC_HOP_ID_0	0xe0
+#define LOWPAN_NHC_HOP_MASK_0	0xfe
+
+static void hop_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_HOP_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_HOP_MASK_0;
+}
+
+LOWPAN_NHC(nhc_hop, "RFC6282 Hop-by-Hop Options", NEXTHDR_HOP, 0,
+	   hop_nhid_setup, LOWPAN_NHC_HOP_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_hop);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Hop-by-Hop Options compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_ipv6.c b/net/6lowpan/nhc_ipv6.c
new file mode 100644
index 000000000000..2313d1600af3
--- /dev/null
+++ b/net/6lowpan/nhc_ipv6.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_IPV6_IDLEN	1
+#define LOWPAN_NHC_IPV6_ID_0	0xee
+#define LOWPAN_NHC_IPV6_MASK_0	0xfe
+
+static void ipv6_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_IPV6_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_IPV6_MASK_0;
+}
+
+LOWPAN_NHC(nhc_ipv6, "RFC6282 IPv6", NEXTHDR_IPV6, 0, ipv6_nhid_setup,
+	   LOWPAN_NHC_IPV6_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_ipv6);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 IPv6 compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_mobility.c b/net/6lowpan/nhc_mobility.c
new file mode 100644
index 000000000000..60d3f3886c98
--- /dev/null
+++ b/net/6lowpan/nhc_mobility.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Mobility Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_MOBILITY_IDLEN	1
+#define LOWPAN_NHC_MOBILITY_ID_0	0xe8
+#define LOWPAN_NHC_MOBILITY_MASK_0	0xfe
+
+static void mobility_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_MOBILITY_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_MOBILITY_MASK_0;
+}
+
+LOWPAN_NHC(nhc_mobility, "RFC6282 Mobility", NEXTHDR_MOBILITY, 0,
+	   mobility_nhid_setup, LOWPAN_NHC_MOBILITY_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_mobility);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Mobility compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_routing.c b/net/6lowpan/nhc_routing.c
new file mode 100644
index 000000000000..c393280f11c4
--- /dev/null
+++ b/net/6lowpan/nhc_routing.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Routing Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_ROUTING_IDLEN	1
+#define LOWPAN_NHC_ROUTING_ID_0		0xe2
+#define LOWPAN_NHC_ROUTING_MASK_0	0xfe
+
+static void routing_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_ROUTING_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_ROUTING_MASK_0;
+}
+
+LOWPAN_NHC(nhc_routing, "RFC6282 Routing", NEXTHDR_ROUTING, 0,
+	   routing_nhid_setup, LOWPAN_NHC_ROUTING_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_routing);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Routing compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c
new file mode 100644
index 000000000000..c6bcaeb428ae
--- /dev/null
+++ b/net/6lowpan/nhc_udp.c
@@ -0,0 +1,157 @@
+/*
+ *	6LoWPAN IPv6 UDP compression according to RFC6282
+ *
+ *
+ *	Authors:
+ *	Alexander Aring	<aar@pengutronix.de>
+ *
+ *	Orignal written by:
+ *	Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ *	Jon Smirl <jonsmirl@gmail.com>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_UDP_IDLEN	1
+
+static int udp_uncompress(struct sk_buff *skb, size_t needed)
+{
+	u8 tmp = 0, val = 0;
+	struct udphdr uh;
+	bool fail;
+	int err;
+
+	fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp));
+
+	pr_debug("UDP header uncompression\n");
+	switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
+	case LOWPAN_NHC_UDP_CS_P_00:
+		fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source));
+		fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest));
+		break;
+	case LOWPAN_NHC_UDP_CS_P_01:
+		fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source));
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
+		break;
+	case LOWPAN_NHC_UDP_CS_P_10:
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
+		fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest));
+		break;
+	case LOWPAN_NHC_UDP_CS_P_11:
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.source = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val >> 4));
+		uh.dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val & 0x0f));
+		break;
+	default:
+		BUG();
+	}
+
+	pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
+		 ntohs(uh.source), ntohs(uh.dest));
+
+	/* checksum */
+	if (tmp & LOWPAN_NHC_UDP_CS_C) {
+		pr_debug_ratelimited("checksum elided currently not supported\n");
+		fail = true;
+	} else {
+		fail |= lowpan_fetch_skb(skb, &uh.check, sizeof(uh.check));
+	}
+
+	if (fail)
+		return -EINVAL;
+
+	/* UDP length needs to be infered from the lower layers
+	 * here, we obtain the hint from the remaining size of the
+	 * frame
+	 */
+	uh.len = htons(skb->len + sizeof(struct udphdr));
+	pr_debug("uncompressed UDP length: src = %d", ntohs(uh.len));
+
+	/* replace the compressed UDP head by the uncompressed UDP
+	 * header
+	 */
+	err = skb_cow(skb, needed);
+	if (unlikely(err))
+		return err;
+
+	skb_push(skb, sizeof(struct udphdr));
+	skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
+
+	return 0;
+}
+
+static int udp_compress(struct sk_buff *skb, u8 **hc_ptr)
+{
+	const struct udphdr *uh = udp_hdr(skb);
+	u8 tmp;
+
+	if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) ==
+	     LOWPAN_NHC_UDP_4BIT_PORT) &&
+	    ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) ==
+	     LOWPAN_NHC_UDP_4BIT_PORT)) {
+		pr_debug("UDP header: both ports compression to 4 bits\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_11;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source and destination port */
+		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
+		      ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+	} else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
+			LOWPAN_NHC_UDP_8BIT_PORT) {
+		pr_debug("UDP header: remove 8 bits of dest\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_01;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
+		/* destination port */
+		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+	} else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
+			LOWPAN_NHC_UDP_8BIT_PORT) {
+		pr_debug("UDP header: remove 8 bits of source\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_10;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* destination port */
+		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
+	} else {
+		pr_debug("UDP header: can't compress\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_00;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
+		/* destination port */
+		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
+	}
+
+	/* checksum is always inline */
+	lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check));
+
+	return 0;
+}
+
+static void udp_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_UDP_ID;
+	nhc->idmask[0] = LOWPAN_NHC_UDP_MASK;
+}
+
+LOWPAN_NHC(nhc_udp, "RFC6282 UDP", NEXTHDR_UDP, sizeof(struct udphdr),
+	   udp_nhid_setup, LOWPAN_NHC_UDP_IDLEN, udp_uncompress, udp_compress);
+
+module_lowpan_nhc(nhc_udp);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 UDP compression");
+MODULE_LICENSE("GPL");
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-09-24 17:17:18 +0000