This patch move UDP header compression and uncompression into the
generic 6LoWPAN nhc header compression layer. Moreover this patch
activates the nhc layer compression in iphc compression and
uncompression functions.
Signed-off-by: Alexander Aring <alex.aring@xxxxxxxxx>
Cc: Jukka Rissanen <jukka.rissanen@xxxxxxxxxxxxxxx>
Cc: Martin Townsend <mtownsend1973@xxxxxxxxx>
---
net/6lowpan/Kconfig | 7 ++
net/6lowpan/Makefile | 4 +-
net/6lowpan/iphc.c | 176 ++++----------------------------------------------
net/6lowpan/nhc_udp.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 191 insertions(+), 165 deletions(-)
create mode 100644 net/6lowpan/nhc_udp.c
diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig
index e4a02ef..cb037e0 100644
--- a/net/6lowpan/Kconfig
+++ b/net/6lowpan/Kconfig
@@ -4,3 +4,10 @@ config 6LOWPAN
---help---
This enables IPv6 over Low power Wireless Personal Area Network -
"6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks.
+
+config 6LOWPAN_UDP
+ tristate "6LoWPAN UDP compression"
+ depends on 6LOWPAN
+ default y
+ ---help---
+ This enables support for 6LoWPAN UDP compression according RFC6282.
diff --git a/net/6lowpan/Makefile b/net/6lowpan/Makefile
index 4215602..24fc27f 100644
--- a/net/6lowpan/Makefile
+++ b/net/6lowpan/Makefile
@@ -1,3 +1,5 @@
-obj-$(CONFIG_6LOWPAN) := 6lowpan.o
+obj-$(CONFIG_6LOWPAN) += 6lowpan.o
+obj-$(CONFIG_6LOWPAN_UDP) += 6lowpan_udp.o
6lowpan-y := iphc.o nhc.o
+6lowpan_udp-y := nhc_udp.o
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index aced97d..dd029ef 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -57,6 +57,8 @@
#include <net/ipv6.h>
#include <net/af_ieee802154.h>
+#include "nhc.h"
+
/* Uncompress address function for source and
* destination address(non-multicast).
*
@@ -227,77 +229,6 @@ 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 };
@@ -430,27 +361,9 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
/* UDP 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, &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))
@@ -503,79 +416,15 @@ 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)
{
u8 tmp, iphc0, iphc1, *hc_ptr;
+ struct lowpan_nhc *nhc;
struct ipv6hdr *hdr;
u8 head[100] = {};
- int addr_type;
+ int ret, addr_type;
if (type != ETH_P_IPV6)
return -EINVAL;
@@ -652,11 +501,10 @@ 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)
+ nhc = lowpan_nhc_by_nexthdr(hdr->nexthdr);
+ if (nhc)
iphc0 |= LOWPAN_IPHC_NH_C;
-
- if ((iphc0 & LOWPAN_IPHC_NH_C) == 0)
+ else
lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
sizeof(hdr->nexthdr));
@@ -744,9 +592,9 @@ 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);
+ ret = lowpan_nhc_do_compression(nhc, skb, &hc_ptr, &iphc0);
+ if (ret < 0)
+ return ret;
head[0] = iphc0;
head[1] = iphc1;
diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c
new file mode 100644
index 0000000..0f6de5fc
--- /dev/null
+++ b/net/6lowpan/nhc_udp.c
@@ -0,0 +1,169 @@
+/*
+ * 6LoWPAN IPv6 UDP compression
+ *
+ *
+ * Authors:
+ * Alexander Aring <aar@xxxxxxxxxxxxxx>
+ *
+ * Orignal written by:
+ * Alexander Smirnov <alex.bluesman.smirnov@xxxxxxxxx>
+ * Jon Smirl <jonsmirl@xxxxxxxxx>
+ *
+ * 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/module.h>
+
+#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)
+{
+ 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));
+
+ 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(udp_nhc, "IPv6 UDP Header", NEXTHDR_UDP, sizeof(struct udphdr),
+ udp_nhid_setup, LOWPAN_NHC_UDP_IDLEN, udp_uncompress, udp_compress);
+
+module_lowpan_nhc(udp_nhc);
+MODULE_LICENSE("GPL");
--
2.1.3
--
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