lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

6LoWPAN: UDP header compression

Browse Source 
This patch adds support for UDP header compression.
Derived from Contiki OS.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
alex.bluesman.smirnov@gmail.com
2011-11-10 07:40:14 +00:00
committed by David S. Miller
parent 4d039f6843
commit 3bd5b958c2
2 changed files with 52 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
net/ieee802154/6lowpan.c
View File

@@ -246,6 +246,50 @@ lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
return 0; return 0;
} }
static void
lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
{
struct udphdr *uh = udp_hdr(skb);
pr_debug("(%s): UDP header compression\n", __func__);
if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
LOWPAN_NHC_UDP_4BIT_PORT) &&
((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
LOWPAN_NHC_UDP_4BIT_PORT)) {
pr_debug("(%s): both ports compression to 4 bits\n", __func__);
**hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
**(hc06_ptr + 1) = /* subtraction is faster */
(u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
*hc06_ptr += 2;
} else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
LOWPAN_NHC_UDP_8BIT_PORT) {
pr_debug("(%s): remove 8 bits of dest\n", __func__);
**hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
memcpy(*hc06_ptr + 1, &uh->source, 2);
**(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
*hc06_ptr += 4;
} else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
LOWPAN_NHC_UDP_8BIT_PORT) {
pr_debug("(%s): remove 8 bits of source\n", __func__);
**hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
memcpy(*hc06_ptr + 1, &uh->dest, 2);
**(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
*hc06_ptr += 4;
} else {
pr_debug("(%s): can't compress header\n", __func__);
**hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
memcpy(*hc06_ptr + 1, &uh->source, 2);
memcpy(*hc06_ptr + 3, &uh->dest, 2);
*hc06_ptr += 5;
}
/* checksum is always inline */
memcpy(*hc06_ptr, &uh->check, 2);
*hc06_ptr += 2;
}
static u8 lowpan_fetch_skb_u8(struct sk_buff *skb) static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
{ {
u8 ret; u8 ret;
@@ -365,8 +409,6 @@ static int lowpan_header_create(struct sk_buff *skb,
if (hdr->nexthdr == UIP_PROTO_UDP) if (hdr->nexthdr == UIP_PROTO_UDP)
iphc0 |= LOWPAN_IPHC_NH_C; iphc0 |= LOWPAN_IPHC_NH_C;
/* TODO: next header compression */
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
*hc06_ptr = hdr->nexthdr; *hc06_ptr = hdr->nexthdr;
hc06_ptr += 1; hc06_ptr += 1;
@@ -454,8 +496,9 @@ static int lowpan_header_create(struct sk_buff *skb,
} }
} }
/* TODO: UDP header compression */ /* UDP header compression */
/* TODO: Next Header compression */ if (hdr->nexthdr == UIP_PROTO_UDP)
lowpan_compress_udp_header(&hc06_ptr, skb);
head[0] = iphc0; head[0] = iphc0;
head[1] = iphc1; head[1] = iphc1;

5
net/ieee802154/6lowpan.h
View File

@@ -219,6 +219,11 @@
#define LOWPAN_NHC_UDP_CHECKSUMC 0x04 #define LOWPAN_NHC_UDP_CHECKSUMC 0x04
#define LOWPAN_NHC_UDP_CHECKSUMI 0x00 #define LOWPAN_NHC_UDP_CHECKSUMI 0x00
#define LOWPAN_NHC_UDP_4BIT_PORT 0xF0B0
#define LOWPAN_NHC_UDP_4BIT_MASK 0xFFF0
#define LOWPAN_NHC_UDP_8BIT_PORT 0xF000
#define LOWPAN_NHC_UDP_8BIT_MASK 0xFF00
/* values for port compression, _with checksum_ ie bit 5 set to 0 */ /* values for port compression, _with checksum_ ie bit 5 set to 0 */
#define LOWPAN_NHC_UDP_CS_P_00 0xF0 /* all inline */ #define LOWPAN_NHC_UDP_CS_P_00 0xF0 /* all inline */
#define LOWPAN_NHC_UDP_CS_P_01 0xF1 /* source 16bit inline, #define LOWPAN_NHC_UDP_CS_P_01 0xF1 /* source 16bit inline,