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-rw-r--r--net/6lowpan/iphc.c677
1 files changed, 464 insertions, 213 deletions
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index 78c8a495b571..346b5c1a9185 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -49,36 +49,178 @@
#include <linux/bitops.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
+
#include <net/6lowpan.h>
#include <net/ipv6.h>
-#include <net/af_ieee802154.h>
+
+/* special link-layer handling */
+#include <net/mac802154.h>
#include "nhc.h"
+/* Values of fields within the IPHC encoding first byte */
+#define LOWPAN_IPHC_TF_MASK 0x18
+#define LOWPAN_IPHC_TF_00 0x00
+#define LOWPAN_IPHC_TF_01 0x08
+#define LOWPAN_IPHC_TF_10 0x10
+#define LOWPAN_IPHC_TF_11 0x18
+
+#define LOWPAN_IPHC_NH 0x04
+
+#define LOWPAN_IPHC_HLIM_MASK 0x03
+#define LOWPAN_IPHC_HLIM_00 0x00
+#define LOWPAN_IPHC_HLIM_01 0x01
+#define LOWPAN_IPHC_HLIM_10 0x02
+#define LOWPAN_IPHC_HLIM_11 0x03
+
+/* Values of fields within the IPHC encoding second byte */
+#define LOWPAN_IPHC_CID 0x80
+
+#define LOWPAN_IPHC_SAC 0x40
+
+#define LOWPAN_IPHC_SAM_MASK 0x30
+#define LOWPAN_IPHC_SAM_00 0x00
+#define LOWPAN_IPHC_SAM_01 0x10
+#define LOWPAN_IPHC_SAM_10 0x20
+#define LOWPAN_IPHC_SAM_11 0x30
+
+#define LOWPAN_IPHC_M 0x08
+
+#define LOWPAN_IPHC_DAC 0x04
+
+#define LOWPAN_IPHC_DAM_MASK 0x03
+#define LOWPAN_IPHC_DAM_00 0x00
+#define LOWPAN_IPHC_DAM_01 0x01
+#define LOWPAN_IPHC_DAM_10 0x02
+#define LOWPAN_IPHC_DAM_11 0x03
+
+/* ipv6 address based on mac
+ * second bit-flip (Universe/Local) is done according RFC2464
+ */
+#define is_addr_mac_addr_based(a, m) \
+ ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
+ (((a)->s6_addr[9]) == (m)[1]) && \
+ (((a)->s6_addr[10]) == (m)[2]) && \
+ (((a)->s6_addr[11]) == (m)[3]) && \
+ (((a)->s6_addr[12]) == (m)[4]) && \
+ (((a)->s6_addr[13]) == (m)[5]) && \
+ (((a)->s6_addr[14]) == (m)[6]) && \
+ (((a)->s6_addr[15]) == (m)[7]))
+
+/* check whether we can compress the IID to 16 bits,
+ * it's possible for unicast addresses with first 49 bits are zero only.
+ */
+#define lowpan_is_iid_16_bit_compressable(a) \
+ ((((a)->s6_addr16[4]) == 0) && \
+ (((a)->s6_addr[10]) == 0) && \
+ (((a)->s6_addr[11]) == 0xff) && \
+ (((a)->s6_addr[12]) == 0xfe) && \
+ (((a)->s6_addr[13]) == 0))
+
+/* check whether the 112-bit gid of the multicast address is mappable to: */
+
+/* 48 bits, FFXX::00XX:XXXX:XXXX */
+#define lowpan_is_mcast_addr_compressable48(a) \
+ ((((a)->s6_addr16[1]) == 0) && \
+ (((a)->s6_addr16[2]) == 0) && \
+ (((a)->s6_addr16[3]) == 0) && \
+ (((a)->s6_addr16[4]) == 0) && \
+ (((a)->s6_addr[10]) == 0))
+
+/* 32 bits, FFXX::00XX:XXXX */
+#define lowpan_is_mcast_addr_compressable32(a) \
+ ((((a)->s6_addr16[1]) == 0) && \
+ (((a)->s6_addr16[2]) == 0) && \
+ (((a)->s6_addr16[3]) == 0) && \
+ (((a)->s6_addr16[4]) == 0) && \
+ (((a)->s6_addr16[5]) == 0) && \
+ (((a)->s6_addr[12]) == 0))
+
+/* 8 bits, FF02::00XX */
+#define lowpan_is_mcast_addr_compressable8(a) \
+ ((((a)->s6_addr[1]) == 2) && \
+ (((a)->s6_addr16[1]) == 0) && \
+ (((a)->s6_addr16[2]) == 0) && \
+ (((a)->s6_addr16[3]) == 0) && \
+ (((a)->s6_addr16[4]) == 0) && \
+ (((a)->s6_addr16[5]) == 0) && \
+ (((a)->s6_addr16[6]) == 0) && \
+ (((a)->s6_addr[14]) == 0))
+
+static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
+ const void *lladdr)
+{
+ /* fe:80::XXXX:XXXX:XXXX:XXXX
+ * \_________________/
+ * hwaddr
+ */
+ ipaddr->s6_addr[0] = 0xFE;
+ ipaddr->s6_addr[1] = 0x80;
+ memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
+ /* second bit-flip (Universe/Local)
+ * is done according RFC2464
+ */
+ ipaddr->s6_addr[8] ^= 0x02;
+}
+
+static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
+ const void *lladdr)
+{
+ const struct ieee802154_addr *addr = lladdr;
+ u8 eui64[EUI64_ADDR_LEN] = { };
+
+ switch (addr->mode) {
+ case IEEE802154_ADDR_LONG:
+ ieee802154_le64_to_be64(eui64, &addr->extended_addr);
+ iphc_uncompress_eui64_lladdr(ipaddr, eui64);
+ break;
+ case IEEE802154_ADDR_SHORT:
+ /* fe:80::ff:fe00:XXXX
+ * \__/
+ * short_addr
+ *
+ * Universe/Local bit is zero.
+ */
+ ipaddr->s6_addr[0] = 0xFE;
+ ipaddr->s6_addr[1] = 0x80;
+ ipaddr->s6_addr[11] = 0xFF;
+ ipaddr->s6_addr[12] = 0xFE;
+ ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
+ &addr->short_addr);
+ break;
+ default:
+ /* should never handled and filtered by 802154 6lowpan */
+ WARN_ON_ONCE(1);
+ break;
+ }
+}
+
/* Uncompress address function for source and
* destination address(non-multicast).
*
- * address_mode is sam value or dam value.
+ * address_mode is the masked value for sam or dam value
*/
-static int uncompress_addr(struct sk_buff *skb,
- struct in6_addr *ipaddr, const u8 address_mode,
- const u8 *lladdr, const u8 addr_type,
- const u8 addr_len)
+static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev,
+ struct in6_addr *ipaddr, u8 address_mode,
+ const void *lladdr)
{
bool fail;
switch (address_mode) {
- case LOWPAN_IPHC_ADDR_00:
+ /* SAM and DAM are the same here */
+ case LOWPAN_IPHC_DAM_00:
/* for global link addresses */
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
- case LOWPAN_IPHC_ADDR_01:
+ case LOWPAN_IPHC_SAM_01:
+ case LOWPAN_IPHC_DAM_01:
/* fe:80::XXXX:XXXX:XXXX:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
break;
- case LOWPAN_IPHC_ADDR_02:
+ case LOWPAN_IPHC_SAM_10:
+ case LOWPAN_IPHC_DAM_10:
/* fe:80::ff:fe00:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
@@ -86,38 +228,16 @@ static int uncompress_addr(struct sk_buff *skb,
ipaddr->s6_addr[12] = 0xFE;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
break;
- case LOWPAN_IPHC_ADDR_03:
+ case LOWPAN_IPHC_SAM_11:
+ case LOWPAN_IPHC_DAM_11:
fail = false;
- switch (addr_type) {
- case IEEE802154_ADDR_LONG:
- /* fe:80::XXXX:XXXX:XXXX:XXXX
- * \_________________/
- * hwaddr
- */
- ipaddr->s6_addr[0] = 0xFE;
- ipaddr->s6_addr[1] = 0x80;
- memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
- /* second bit-flip (Universe/Local)
- * is done according RFC2464
- */
- ipaddr->s6_addr[8] ^= 0x02;
- break;
- case IEEE802154_ADDR_SHORT:
- /* fe:80::ff:fe00:XXXX
- * \__/
- * short_addr
- *
- * Universe/Local bit is zero.
- */
- ipaddr->s6_addr[0] = 0xFE;
- ipaddr->s6_addr[1] = 0x80;
- ipaddr->s6_addr[11] = 0xFF;
- ipaddr->s6_addr[12] = 0xFE;
- ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
+ switch (lowpan_priv(dev)->lltype) {
+ case LOWPAN_LLTYPE_IEEE802154:
+ iphc_uncompress_802154_lladdr(ipaddr, lladdr);
break;
default:
- pr_debug("Invalid addr_type set\n");
- return -EINVAL;
+ iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
+ break;
}
break;
default:
@@ -141,24 +261,25 @@ static int uncompress_addr(struct sk_buff *skb,
*/
static int uncompress_context_based_src_addr(struct sk_buff *skb,
struct in6_addr *ipaddr,
- const u8 sam)
+ u8 address_mode)
{
- switch (sam) {
- case LOWPAN_IPHC_ADDR_00:
+ switch (address_mode) {
+ case LOWPAN_IPHC_SAM_00:
/* unspec address ::
* Do nothing, address is already ::
*/
break;
- case LOWPAN_IPHC_ADDR_01:
+ case LOWPAN_IPHC_SAM_01:
/* TODO */
- case LOWPAN_IPHC_ADDR_02:
+ case LOWPAN_IPHC_SAM_10:
/* TODO */
- case LOWPAN_IPHC_ADDR_03:
+ case LOWPAN_IPHC_SAM_11:
/* TODO */
- netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
+ netdev_warn(skb->dev, "SAM value 0x%x not supported\n",
+ address_mode);
return -EINVAL;
default:
- pr_debug("Invalid sam value: 0x%x\n", sam);
+ pr_debug("Invalid sam value: 0x%x\n", address_mode);
return -EINVAL;
}
@@ -174,11 +295,11 @@ static int uncompress_context_based_src_addr(struct sk_buff *skb,
*/
static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
struct in6_addr *ipaddr,
- const u8 dam)
+ u8 address_mode)
{
bool fail;
- switch (dam) {
+ switch (address_mode) {
case LOWPAN_IPHC_DAM_00:
/* 00: 128 bits. The full address
* is carried in-line.
@@ -210,7 +331,7 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
break;
default:
- pr_debug("DAM value has a wrong value: 0x%x\n", dam);
+ pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
return -EINVAL;
}
@@ -225,77 +346,142 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
return 0;
}
-/* TTL uncompression values */
-static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
-
-int
-lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
- const u8 *saddr, const u8 saddr_type,
- const u8 saddr_len, const u8 *daddr,
- const u8 daddr_type, const u8 daddr_len,
- u8 iphc0, u8 iphc1)
+/* get the ecn values from iphc tf format and set it to ipv6hdr */
+static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
{
- struct ipv6hdr hdr = {};
- u8 tmp, num_context = 0;
- int err;
+ /* get the two higher bits which is ecn */
+ u8 ecn = tf[0] & 0xc0;
- raw_dump_table(__func__, "raw skb data dump uncompressed",
- skb->data, skb->len);
+ /* ECN takes 0x30 in hdr->flow_lbl[0] */
+ hdr->flow_lbl[0] |= (ecn >> 2);
+}
- /* another if the CID flag is set */
- if (iphc1 & LOWPAN_IPHC_CID) {
- pr_debug("CID flag is set, increase header with one\n");
- if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
- return -EINVAL;
- }
+/* get the dscp values from iphc tf format and set it to ipv6hdr */
+static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
+{
+ /* DSCP is at place after ECN */
+ u8 dscp = tf[0] & 0x3f;
- hdr.version = 6;
+ /* The four highest bits need to be set at hdr->priority */
+ hdr->priority |= ((dscp & 0x3c) >> 2);
+ /* The two lower bits is part of hdr->flow_lbl[0] */
+ hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
+}
- /* Traffic Class and Flow Label */
- switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
- /* Traffic Class and FLow Label carried in-line
- * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
+/* get the flow label values from iphc tf format and set it to ipv6hdr */
+static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
+{
+ /* flow label is always some array started with lower nibble of
+ * flow_lbl[0] and followed with two bytes afterwards. Inside inline
+ * data the flow_lbl position can be different, which will be handled
+ * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
+ * shifted, the different lbl pointer will handle that.
+ *
+ * The flow label will started at lower nibble of flow_lbl[0], the
+ * higher nibbles are part of DSCP + ECN.
*/
- case 0: /* 00b */
- if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+ hdr->flow_lbl[0] |= lbl[0] & 0x0f;
+ memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
+}
+
+/* lowpan_iphc_tf_decompress - decompress the traffic class.
+ * This function will return zero on success, a value lower than zero if
+ * failed.
+ */
+static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
+ u8 val)
+{
+ u8 tf[4];
+
+ /* Traffic Class and Flow Label */
+ switch (val) {
+ case LOWPAN_IPHC_TF_00:
+ /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
+ if (lowpan_fetch_skb(skb, tf, 4))
return -EINVAL;
- memcpy(&hdr.flow_lbl, &skb->data[0], 3);
- skb_pull(skb, 3);
- hdr.priority = ((tmp >> 2) & 0x0f);
- hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
- (hdr.flow_lbl[0] & 0x0f);
+ /* 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |ECN| DSCP | rsv | Flow Label |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ lowpan_iphc_tf_set_ecn(hdr, tf);
+ lowpan_iphc_tf_set_dscp(hdr, tf);
+ lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
break;
- /* Traffic class carried in-line
- * ECN + DSCP (1 byte), Flow Label is elided
- */
- case 2: /* 10b */
- if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+ case LOWPAN_IPHC_TF_01:
+ /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
+ if (lowpan_fetch_skb(skb, tf, 3))
return -EINVAL;
- hdr.priority = ((tmp >> 2) & 0x0f);
- hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
+ /* 1 2
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |ECN|rsv| Flow Label |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ lowpan_iphc_tf_set_ecn(hdr, tf);
+ lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
break;
- /* Flow Label carried in-line
- * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
- */
- case 1: /* 01b */
- if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+ case LOWPAN_IPHC_TF_10:
+ /* ECN + DSCP (1 byte), Flow Label is elided. */
+ if (lowpan_fetch_skb(skb, tf, 1))
return -EINVAL;
- hdr.flow_lbl[0] = (tmp & 0x0F) | ((tmp >> 2) & 0x30);
- memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
- skb_pull(skb, 2);
+ /* 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * |ECN| DSCP |
+ * +-+-+-+-+-+-+-+-+
+ */
+ lowpan_iphc_tf_set_ecn(hdr, tf);
+ lowpan_iphc_tf_set_dscp(hdr, tf);
break;
- /* Traffic Class and Flow Label are elided */
- case 3: /* 11b */
+ case LOWPAN_IPHC_TF_11:
+ /* Traffic Class and Flow Label are elided */
break;
default:
- break;
+ WARN_ON_ONCE(1);
+ return -EINVAL;
}
+ return 0;
+}
+
+/* TTL uncompression values */
+static const u8 lowpan_ttl_values[] = {
+ [LOWPAN_IPHC_HLIM_01] = 1,
+ [LOWPAN_IPHC_HLIM_10] = 64,
+ [LOWPAN_IPHC_HLIM_11] = 255,
+};
+
+int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
+ const void *daddr, const void *saddr)
+{
+ struct ipv6hdr hdr = {};
+ u8 iphc0, iphc1;
+ int err;
+
+ raw_dump_table(__func__, "raw skb data dump uncompressed",
+ skb->data, skb->len);
+
+ if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
+ lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
+ return -EINVAL;
+
+ /* another if the CID flag is set */
+ if (iphc1 & LOWPAN_IPHC_CID)
+ return -ENOTSUPP;
+
+ hdr.version = 6;
+
+ err = lowpan_iphc_tf_decompress(skb, &hdr,
+ iphc0 & LOWPAN_IPHC_TF_MASK);
+ if (err < 0)
+ return err;
+
/* Next Header */
- if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+ if (!(iphc0 & LOWPAN_IPHC_NH)) {
/* Next header is carried inline */
if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
return -EINVAL;
@@ -305,35 +491,30 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
}
/* Hop Limit */
- if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) {
- hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
+ if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
+ hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
} else {
if (lowpan_fetch_skb(skb, &hdr.hop_limit,
sizeof(hdr.hop_limit)))
return -EINVAL;
}
- /* Extract SAM to the tmp variable */
- tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
-
if (iphc1 & LOWPAN_IPHC_SAC) {
/* Source address context based uncompression */
pr_debug("SAC bit is set. Handle context based source address.\n");
- err = uncompress_context_based_src_addr(skb, &hdr.saddr, tmp);
+ err = uncompress_context_based_src_addr(skb, &hdr.saddr,
+ iphc1 & LOWPAN_IPHC_SAM_MASK);
} else {
/* Source address uncompression */
pr_debug("source address stateless compression\n");
- err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
- saddr_type, saddr_len);
+ err = uncompress_addr(skb, dev, &hdr.saddr,
+ iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
}
/* Check on error of previous branch */
if (err)
return -EINVAL;
- /* Extract DAM to the tmp variable */
- tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
-
/* check for Multicast Compression */
if (iphc1 & LOWPAN_IPHC_M) {
if (iphc1 & LOWPAN_IPHC_DAC) {
@@ -341,22 +522,22 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
/* TODO: implement this */
} else {
err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
- tmp);
+ iphc1 & LOWPAN_IPHC_DAM_MASK);
if (err)
return -EINVAL;
}
} else {
- err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
- daddr_type, daddr_len);
+ err = uncompress_addr(skb, dev, &hdr.daddr,
+ iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
pr_debug("dest: stateless compression mode %d dest %pI6c\n",
- tmp, &hdr.daddr);
+ iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
if (err)
return -EINVAL;
}
/* Next header data uncompression */
- if (iphc0 & LOWPAN_IPHC_NH_C) {
+ if (iphc0 & LOWPAN_IPHC_NH) {
err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
if (err < 0)
return err;
@@ -397,42 +578,176 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
}
EXPORT_SYMBOL_GPL(lowpan_header_decompress);
-static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
- const struct in6_addr *ipaddr,
- const unsigned char *lladdr)
+static const u8 lowpan_iphc_dam_to_sam_value[] = {
+ [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
+ [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
+ [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
+ [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
+};
+
+static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
+ const unsigned char *lladdr, bool sam)
{
- u8 val = 0;
+ u8 dam = LOWPAN_IPHC_DAM_00;
if (is_addr_mac_addr_based(ipaddr, lladdr)) {
- val = 3; /* 0-bits */
+ dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
pr_debug("address compression 0 bits\n");
} else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
/* compress IID to 16 bits xxxx::XXXX */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
- val = 2; /* 16-bits */
+ dam = LOWPAN_IPHC_DAM_10; /* 16-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
*hc_ptr - 2, 2);
} else {
/* do not compress IID => xxxx::IID */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
- val = 1; /* 64-bits */
+ dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
*hc_ptr - 8, 8);
}
- return rol8(val, shift);
+ if (sam)
+ return lowpan_iphc_dam_to_sam_value[dam];
+ else
+ return dam;
}
-int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
- unsigned short type, const void *_daddr,
- const void *_saddr, unsigned int len)
+/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
+static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
{
- u8 tmp, iphc0, iphc1, *hc_ptr;
+ u8 dscp, ecn;
+
+ /* hdr->priority contains the higher bits of dscp, lower are part of
+ * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
+ */
+ dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
+ /* ECN is at the two lower bits from first nibble of flow_lbl[0] */
+ ecn = (hdr->flow_lbl[0] & 0x30);
+ /* for pretty debug output, also shift ecn to get the ecn value */
+ pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
+ /* ECN is at 0x30 now, shift it to have ECN + DCSP */
+ return (ecn << 2) | dscp;
+}
+
+/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
+static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
+{
+ return ((!(hdr->flow_lbl[0] & 0x0f)) &&
+ !hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
+}
+
+/* lowpan_iphc_tf_compress - compress the traffic class which is set by
+ * ipv6hdr. Return the corresponding format identifier which is used.
+ */
+static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
+{
+ /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
+ u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
+
+ /* printout the traffic class in hc format */
+ pr_debug("tc 0x%02x\n", tc);
+
+ if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
+ if (!tc) {
+ /* 11: Traffic Class and Flow Label are elided. */
+ val = LOWPAN_IPHC_TF_11;
+ } else {
+ /* 10: ECN + DSCP (1 byte), Flow Label is elided.
+ *
+ * 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * |ECN| DSCP |
+ * +-+-+-+-+-+-+-+-+
+ */
+ lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
+ val = LOWPAN_IPHC_TF_10;
+ }
+ } else {
+ /* check if dscp is zero, it's after the first two bit */
+ if (!(tc & 0x3f)) {
+ /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
+ *
+ * 1 2
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |ECN|rsv| Flow Label |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ memcpy(&tf[0], &hdr->flow_lbl[0], 3);
+ /* zero the highest 4-bits, contains DCSP + ECN */
+ tf[0] &= ~0xf0;
+ /* set ECN */
+ tf[0] |= (tc & 0xc0);
+
+ lowpan_push_hc_data(hc_ptr, tf, 3);
+ val = LOWPAN_IPHC_TF_01;
+ } else {
+ /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
+ *
+ * 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |ECN| DSCP | rsv | Flow Label |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ memcpy(&tf[0], &tc, sizeof(tc));
+ /* highest nibble of flow_lbl[0] is part of DSCP + ECN
+ * which will be the 4-bit pad and will be filled with
+ * zeros afterwards.
+ */
+ memcpy(&tf[1], &hdr->flow_lbl[0], 3);
+ /* zero the 4-bit pad, which is reserved */
+ tf[1] &= ~0xf0;
+
+ lowpan_push_hc_data(hc_ptr, tf, 4);
+ val = LOWPAN_IPHC_TF_00;
+ }
+ }
+
+ return val;
+}
+
+static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
+ const struct in6_addr *ipaddr)
+{
+ u8 val;
+
+ if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
+ pr_debug("compressed to 1 octet\n");
+ /* use last byte */
+ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
+ val = LOWPAN_IPHC_DAM_11;
+ } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
+ pr_debug("compressed to 4 octets\n");
+ /* second byte + the last three */
+ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
+ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
+ val = LOWPAN_IPHC_DAM_10;
+ } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
+ pr_debug("compressed to 6 octets\n");
+ /* second byte + the last five */
+ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
+ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
+ val = LOWPAN_IPHC_DAM_01;
+ } else {
+ pr_debug("using full address\n");
+ lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
+ val = LOWPAN_IPHC_DAM_00;
+ }
+
+ return val;
+}
+
+int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
+ const void *daddr, const void *saddr)
+{
+ u8 iphc0, iphc1, *hc_ptr;
struct ipv6hdr *hdr;
- u8 head[100] = {};
+ u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
int ret, addr_type;
- if (type != ETH_P_IPV6)
+ if (skb->protocol != htons(ETH_P_IPV6))
return -EINVAL;
hdr = ipv6_hdr(skb);
@@ -456,63 +771,26 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
/* TODO: context lookup */
- raw_dump_inline(__func__, "saddr",
- (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
- raw_dump_inline(__func__, "daddr",
- (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
+ raw_dump_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN);
+ raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN);
raw_dump_table(__func__, "sending raw skb network uncompressed packet",
skb->data, skb->len);
- /* Traffic class, flow label
- * If flow label is 0, compress it. If traffic class is 0, compress it
- * We have to process both in the same time as the offset of traffic
- * class depends on the presence of version and flow label
- */
-
- /* hc format of TC is ECN | DSCP , original one is DSCP | ECN */
- tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
- tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
-
- if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
- (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
- /* flow label can be compressed */
- iphc0 |= LOWPAN_IPHC_FL_C;
- if ((hdr->priority == 0) &&
- ((hdr->flow_lbl[0] & 0xF0) == 0)) {
- /* compress (elide) all */
- iphc0 |= LOWPAN_IPHC_TC_C;
- } else {
- /* compress only the flow label */
- *hc_ptr = tmp;
- hc_ptr += 1;
- }
- } else {
- /* Flow label cannot be compressed */
- if ((hdr->priority == 0) &&
- ((hdr->flow_lbl[0] & 0xF0) == 0)) {
- /* compress only traffic class */
- iphc0 |= LOWPAN_IPHC_TC_C;
- *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
- memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2);
- hc_ptr += 3;
- } else {
- /* compress nothing */
- memcpy(hc_ptr, hdr, 4);
- /* replace the top byte with new ECN | DSCP format */
- *hc_ptr = tmp;
- hc_ptr += 4;
- }
- }
+ /* Traffic Class, Flow Label compression */
+ iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr);
/* NOTE: payload length is always compressed */
/* Check if we provide the nhc format for nexthdr and compression
* functionality. If not nexthdr is handled inline and not compressed.
*/
- ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0);
- if (ret < 0)
- return ret;
+ ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr);
+ if (ret == -ENOENT)
+ lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
+ sizeof(hdr->nexthdr));
+ else
+ iphc0 |= LOWPAN_IPHC_NH;
/* Hop limit
* if 1: compress, encoding is 01
@@ -522,13 +800,13 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
*/
switch (hdr->hop_limit) {
case 1:
- iphc0 |= LOWPAN_IPHC_TTL_1;
+ iphc0 |= LOWPAN_IPHC_HLIM_01;
break;
case 64:
- iphc0 |= LOWPAN_IPHC_TTL_64;
+ iphc0 |= LOWPAN_IPHC_HLIM_10;
break;
case 255:
- iphc0 |= LOWPAN_IPHC_TTL_255;
+ iphc0 |= LOWPAN_IPHC_HLIM_11;
break;
default:
lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
@@ -542,9 +820,8 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
iphc1 |= LOWPAN_IPHC_SAC;
} else {
if (addr_type & IPV6_ADDR_LINKLOCAL) {
- iphc1 |= lowpan_compress_addr_64(&hc_ptr,
- LOWPAN_IPHC_SAM_BIT,
- &hdr->saddr, _saddr);
+ iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->saddr,
+ saddr, true);
pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
&hdr->saddr, iphc1);
} else {
@@ -558,38 +835,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
if (addr_type & IPV6_ADDR_MULTICAST) {
pr_debug("destination address is multicast: ");
iphc1 |= LOWPAN_IPHC_M;
- if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
- pr_debug("compressed to 1 octet\n");
- iphc1 |= LOWPAN_IPHC_DAM_11;
- /* use last byte */
- lowpan_push_hc_data(&hc_ptr,
- &hdr->daddr.s6_addr[15], 1);
- } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
- pr_debug("compressed to 4 octets\n");
- iphc1 |= LOWPAN_IPHC_DAM_10;
- /* second byte + the last three */
- lowpan_push_hc_data(&hc_ptr,
- &hdr->daddr.s6_addr[1], 1);
- lowpan_push_hc_data(&hc_ptr,
- &hdr->daddr.s6_addr[13], 3);
- } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
- pr_debug("compressed to 6 octets\n");
- iphc1 |= LOWPAN_IPHC_DAM_01;
- /* second byte + the last five */
- lowpan_push_hc_data(&hc_ptr,
- &hdr->daddr.s6_addr[1], 1);
- lowpan_push_hc_data(&hc_ptr,
- &hdr->daddr.s6_addr[11], 5);
- } else {
- pr_debug("using full address\n");
- iphc1 |= LOWPAN_IPHC_DAM_00;
- lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
- }
+ iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr, &hdr->daddr);
} else {
if (addr_type & IPV6_ADDR_LINKLOCAL) {
/* TODO: context lookup */
- iphc1 |= lowpan_compress_addr_64(&hc_ptr,
- LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
+ iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->daddr,
+ daddr, false);
pr_debug("dest address unicast link-local %pI6c "
"iphc1 0x%02x\n", &hdr->daddr, iphc1);
} else {
@@ -599,7 +850,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
}
/* next header compression */
- if (iphc0 & LOWPAN_IPHC_NH_C) {
+ if (iphc0 & LOWPAN_IPHC_NH) {
ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
if (ret < 0)
return ret;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.