diff options
| author | alex.bluesman.smirnov@gmail.com <alex.bluesman.smirnov@gmail.com> | 2011-11-10 11:40:14 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-14 09:19:43 +0400 |
| commit | 3bd5b958c2a2dd1a9b4c8d21e75fb47b062fc941 (patch) | |
| tree | 6cdd68759b81cf7115976f730537da76b528723e /net/ieee802154 | |
| parent | 4d039f684314b707fdae3c7262faf4a80c548194 (diff) | |
| download | linux-3bd5b958c2a2dd1a9b4c8d21e75fb47b062fc941.tar.xz | |
6LoWPAN: UDP header compression
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>
Diffstat (limited to 'net/ieee802154')
| -rw-r--r-- | net/ieee802154/6lowpan.c | 51 | ||||
| -rw-r--r-- | net/ieee802154/6lowpan.h | 5 |
2 files changed, 52 insertions, 4 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c index 39ec6e018227..9bf82d72bb9e 100644 --- a/net/ieee802154/6lowpan.c +++ b/net/ieee802154/6lowpan.c @@ -246,6 +246,50 @@ lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr, 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) { u8 ret; @@ -365,8 +409,6 @@ static int lowpan_header_create(struct sk_buff *skb, if (hdr->nexthdr == UIP_PROTO_UDP) iphc0 |= LOWPAN_IPHC_NH_C; -/* TODO: next header compression */ - if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { *hc06_ptr = hdr->nexthdr; hc06_ptr += 1; @@ -454,8 +496,9 @@ static int lowpan_header_create(struct sk_buff *skb, } } - /* TODO: UDP header compression */ - /* TODO: Next Header compression */ + /* UDP header compression */ + if (hdr->nexthdr == UIP_PROTO_UDP) + lowpan_compress_udp_header(&hc06_ptr, skb); head[0] = iphc0; head[1] = iphc1; diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h index 5d2e5a03742f..aeff3f310482 100644 --- a/net/ieee802154/6lowpan.h +++ b/net/ieee802154/6lowpan.h @@ -219,6 +219,11 @@ #define LOWPAN_NHC_UDP_CHECKSUMC 0x04 #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 */ #define LOWPAN_NHC_UDP_CS_P_00 0xF0 /* all inline */ #define LOWPAN_NHC_UDP_CS_P_01 0xF1 /* source 16bit inline, |