This patch drop the pre and postcount calculation from the
lowpan_uncompress_addr function.
We use instead a switch case over address_mode value, it's easier
to understand what's going on there.
Signed-off-by: Alexander Aring <alex.ar...@gmail.com>
---
net/ieee802154/6lowpan.c | 123 ++++++++++++++++++++++-------------------------
net/ieee802154/6lowpan.h | 8 +--
2 files changed, 62 insertions(+), 69 deletions(-)
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 14e29d8..84f05c4 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -67,30 +67,6 @@ static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
static LIST_HEAD(lowpan_devices);
-/*
- * Uncompression of linklocal:
- * 0 -> 16 bytes from packet
- * 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet
- * 2 -> 2 bytes from prefix - zeroes + 2 from packet
- * 3 -> 2 bytes from prefix - infer 8 bytes from lladdr
- *
- * NOTE: => the uncompress function does change 0xf to 0x10
- * NOTE: 0x00 => no-autoconfig => unspecified
- */
-static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
-
-/*
- * Uncompression of ctx-based:
- * 0 -> 0 bits from packet [unspecified / reserved]
- * 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
- * 2 -> 8 bytes from prefix - zeroes + 2 from packet
- * 3 -> 8 bytes from prefix - infer 8 bytes from lladdr
- */
-static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
-
-/* Link local prefix */
-static const u8 lowpan_llprefix[] = {0xfe, 0x80};
-
/* private device info */
struct lowpan_dev_info {
struct net_device *real_dev; /* real WPAN device ptr */
@@ -182,50 +158,67 @@ lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const
struct in6_addr *ipaddr,
return rol8(val, shift);
}
-static void
-lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
-{
- memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ADDR_LEN);
- /* second bit-flip (Universe/Local) is done according RFC2464 */
- ipaddr->s6_addr[8] ^= 0x02;
-}
-
/*
- * Uncompress addresses based on a prefix and a postfix with zeroes in
- * between. If the postfix is zero in length it will use the link address
- * to configure the IP address (autoconf style).
- * pref_post_count takes a byte where the first nibble specify prefix count
- * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
+ * Uncompress address function for source and
+ * destination address(non-multicast).
+ *
+ * address_mode is sam value or dam value.
*/
static int
-lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
- u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
+lowpan_uncompress_addr(struct sk_buff *skb,
+ struct in6_addr *ipaddr,
+ const u8 address_mode,
+ const u8 *layer_addr)
{
- u8 prefcount = pref_post_count >> 4;
- u8 postcount = pref_post_count & 0x0f;
-
- /* full nibble 15 => 16 */
- prefcount = (prefcount == 15 ? 16 : prefcount);
- postcount = (postcount == 15 ? 16 : postcount);
-
- if (lladdr)
- lowpan_raw_dump_inline(__func__, "linklocal address",
- lladdr, IEEE802154_ADDR_LEN);
- if (prefcount > 0)
- memcpy(ipaddr, prefix, prefcount);
-
- if (postcount > 0) {
- memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
- skb_pull(skb, postcount);
- } else if (prefcount > 0) {
- if (lladdr == NULL)
- return -EINVAL;
-
- /* no IID based configuration if no prefix and no data */
- lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
+ switch (address_mode) {
+ case LOWPAN_IPHC_ADDR_00:
+ /*
+ * for global link addresses
+ */
+ memcpy(ipaddr->s6_addr, skb->data, 16);
+ skb_pull(skb, 16);
+ break;
+ case LOWPAN_IPHC_ADDR_01:
+ /*
+ * fe:80::XXXX:XXXX:XXXX:XXXX
+ */
+ memset(&ipaddr->s6_addr[0], 0xFE, 1);
+ memset(&ipaddr->s6_addr[1], 0x80, 1);
+ memcpy(&ipaddr->s6_addr[8], skb->data, 8);
+ skb_pull(skb, 8);
+ break;
+ case LOWPAN_IPHC_ADDR_02:
+ /*
+ * fe:80::ff:fe00:XXXX
+ */
+ memset(&ipaddr->s6_addr[0], 0xFE, 1);
+ memset(&ipaddr->s6_addr[1], 0x80, 1);
+ memset(&ipaddr->s6_addr[11], 0xFF, 1);
+ memset(&ipaddr->s6_addr[12], 0xFE, 1);
+ memcpy(&ipaddr->s6_addr[14], skb->data, 2);
+ skb_pull(skb, 2);
+ break;
+ case LOWPAN_IPHC_ADDR_03:
+ /*
+ * fe:80::XXXX:XXXX:XXXX:XXXX
+ * \_________________/
+ * layer_addr
+ */
+ memset(&ipaddr->s6_addr[0], 0xFE, 1);
+ memset(&ipaddr->s6_addr[1], 0x80, 1);
+ memcpy(&ipaddr->s6_addr[8], layer_addr, IEEE802154_ADDR_LEN);
+ /*
+ * second bit-flip (Universe/Local)
+ * is done according RFC2464
+ */
+ ipaddr->s6_addr[8] ^= 0x02;
+ break;
+ default:
+ pr_debug("Invalid address mode value: 0x%x\n", address_mode);
+ return -EINVAL;
}
- pr_debug("uncompressing %d + %d => ", prefcount, postcount);
+ pr_debug("Reconstructed ipv6 addr is:\n");
lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
return 0;
@@ -960,8 +953,7 @@ lowpan_process_data(struct sk_buff *skb)
/* Source address uncompression */
pr_debug("source address stateless compression\n");
- err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
- lowpan_unc_llconf[tmp], _saddr);
+ err = lowpan_uncompress_addr(skb, &hdr.saddr, tmp, _saddr);
if (err)
goto drop;
@@ -981,8 +973,7 @@ lowpan_process_data(struct sk_buff *skb)
}
} else {
pr_debug("dest: stateless compression\n");
- err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
- lowpan_unc_llconf[tmp], _daddr);
+ err = lowpan_uncompress_addr(skb, &hdr.daddr, tmp, _daddr);
if (err)
goto drop;
}
diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h
index 4b8f917..3b64644 100644
--- a/net/ieee802154/6lowpan.h
+++ b/net/ieee802154/6lowpan.h
@@ -193,10 +193,12 @@
/* Values of fields within the IPHC encoding second byte */
#define LOWPAN_IPHC_CID 0x80
+#define LOWPAN_IPHC_ADDR_00 0x00
+#define LOWPAN_IPHC_ADDR_01 0x01
+#define LOWPAN_IPHC_ADDR_02 0x02
+#define LOWPAN_IPHC_ADDR_03 0x03
+
#define LOWPAN_IPHC_SAC 0x40
-#define LOWPAN_IPHC_SAM_00 0x00
-#define LOWPAN_IPHC_SAM_01 0x10
-#define LOWPAN_IPHC_SAM_10 0x20
#define LOWPAN_IPHC_SAM 0x30
#define LOWPAN_IPHC_SAM_BIT 4
--
1.8.3.2
------------------------------------------------------------------------------
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