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sixlowpan: Refactor DAC/DAM decoding to match SAC/SAM implementation.
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@OlegHahm
Joakim Gebart authored and OlegHahm committed Mar 31, 2015
1 parent ab49df5 commit 7d2f405
Showing 1 changed file with 47 additions and 82 deletions.
129 changes: 47 additions & 82 deletions sys/net/network_layer/sixlowpan/lowpan.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1296,7 +1296,7 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
memset(&(ipv6_buf->srcaddr.uint8[2]), 0, 6);
memcpy(&(ipv6_buf->srcaddr.uint8[8]), &s_addr->uint8[0], 8);
/* Invert Universal/local bit as specified in
* RFC2373, section 2.5.1 "Interface Identifiers" */
* RFC4291, section 2.5.1 "Interface Identifiers" */
ipv6_buf->srcaddr.uint8[8] ^= 0x02;
break;
}
Expand Down Expand Up @@ -1367,25 +1367,10 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
else {
uint8_t m_prefix[2] = {0xff, 0x02};
/* If M=1 and DAC=0: */
switch (lowpan_iphc[1] & 0x03) {
switch (lowpan_iphc[1] & SIXLOWPAN_IPHC2_DAM) {
case (0x01): {
m_prefix[1] = ipv6_hdr_fields[hdr_pos];
hdr_pos++;
break;
}

case (0x02): {
m_prefix[1] = ipv6_hdr_fields[hdr_pos];
hdr_pos++;
break;
}

default:
break;
}

switch (lowpan_iphc[1] & 0x03) {
case (0x01): {
memcpy(&(ipv6_buf->destaddr.uint8[0]), &m_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 9);
memcpy(&(ipv6_buf->destaddr.uint8[11]), &ipv6_hdr_fields[hdr_pos], 5);
Expand All @@ -1394,6 +1379,8 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
}

case (0x02): {
m_prefix[1] = ipv6_hdr_fields[hdr_pos];
hdr_pos++;
memcpy(&(ipv6_buf->destaddr.uint8[0]), &m_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 11);
memcpy(&(ipv6_buf->destaddr.uint8[13]), &ipv6_hdr_fields[hdr_pos], 3);
Expand All @@ -1418,10 +1405,49 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
}
}
else {
switch ((lowpan_iphc[1] & SIXLOWPAN_IPHC2_DAM) & 0x03) {
case (0x01): {
/* 64-bits */
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 6);
memcpy(&(ipv6_buf->destaddr.uint8[8]), &ipv6_hdr_fields[hdr_pos], 8);
hdr_pos += 8;
break;
}

case (0x02): {
/* 16-bits */
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 12);
memcpy(&(ipv6_buf->destaddr.uint8[14]), &ipv6_hdr_fields[hdr_pos], 2);
hdr_pos += 2;
break;
}

case (0x03): {
/* 0-bits */
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 6);
memcpy(&(ipv6_buf->destaddr.uint8[8]), &s_addr->uint8[0], 8);
/* Invert Universal/local bit as specified in
* RFC4291, section 2.5.1 "Interface Identifiers" */
ipv6_buf->destaddr.uint8[8] ^= 0x02;
break;
}

default: {
/* full address carried inline */
memcpy(&(ipv6_buf->destaddr.uint8[0]),
&ipv6_hdr_fields[hdr_pos], 16);
hdr_pos += 16;
break;
}
}

if (lowpan_iphc[1] & SIXLOWPAN_IPHC2_DAC) {
/* 1: Destination address compression uses stateful, context-based
* compression.
* If M=1 and DAC=1: */
* If M=0 and DAC=1: */
if (cid) {
dci = ipv6_hdr_fields[3] & 0x0f;
}
Expand All @@ -1438,73 +1464,12 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
return;
}

switch ((lowpan_iphc[1] & SIXLOWPAN_IPHC2_DAM) & 0x03) {
case (0x01): {
memcpy(&(ipv6_buf->destaddr.uint8[8]), &ipv6_hdr_fields[hdr_pos], 8);
/* By draft-ietf-6lowpan-hc-15 3.1.1. Bits covered by context information are always used. */
memcpy(&(ipv6_buf->srcaddr.uint8[0]), &con->prefix, con->length);
hdr_pos += 8;
break;
}

case (0x02): {
memset(&(ipv6_buf->destaddr.uint8[8]), 0, 6);
memcpy(&(ipv6_buf->destaddr.uint8[14]), &ipv6_hdr_fields[hdr_pos], 2);
/* By draft-ietf-6lowpan-hc-15 3.1.1. Bits covered by context information are always used. */
memcpy(&(ipv6_buf->srcaddr.uint8[0]), &con->prefix, con->length);
hdr_pos += 2;
break;
}

case (0x03): {
memset(&(ipv6_buf->destaddr.uint8[0]), 0, 8);
memcpy(&(ipv6_buf->destaddr.uint8[8]), &d_addr->uint8[0], 8);
/* By draft-ietf-6lowpan-hc-15 3.1.1. Bits covered by context information are always used. */
memcpy(&(ipv6_buf->srcaddr.uint8[0]), &con->prefix, con->length);
break;
}

default:
break;
}
/* By RFC 6282 3.1.1. Bits covered by context
* information are always used. */
memcpy(&(ipv6_buf->destaddr.uint8[0]), &con->prefix, con->length);

mutex_unlock(&lowpan_context_mutex);
}
else {
switch ((lowpan_iphc[1] & SIXLOWPAN_IPHC2_DAM) & 0x03) {
case (0x01): {
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 6);
memcpy(&(ipv6_buf->destaddr.uint8[8]),
&ipv6_hdr_fields[hdr_pos], 8);
hdr_pos += 8;
break;
}

case (0x02): {
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix[0], 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 12);
memcpy(&(ipv6_buf->destaddr.uint8[14]),
&ipv6_hdr_fields[hdr_pos], 2);
hdr_pos += 2;
break;
}

case (0x03): {
memcpy(&(ipv6_buf->destaddr.uint8[0]), &ll_prefix, 2);
memset(&(ipv6_buf->destaddr.uint8[2]), 0, 14);
memcpy(&(ipv6_buf->destaddr.uint8[8]), &d_addr->uint8[0], 8);
break;
}

default: {
memcpy(&(ipv6_buf->destaddr.uint8[0]),
&ipv6_hdr_fields[hdr_pos], 16);
hdr_pos += 16;
break;
}
}
}
}

uint8_t *ptr = get_payload_buf(ipv6_ext_hdr_len);
Expand Down

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