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6lowpan: Moving generic compression code into 6lowpan_iphc.c 

Because the IEEE 802154 and Bluetooth share the IP header compression
and uncompression code, the common code is moved to 6lowpan_iphc.c
file.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Jukka Rissanen 2013-12-11 17:05:34 +02:00 коммит произвёл Marcel Holtmann
Родитель 71fb419724
Коммит 8df8c56a5a
4 изменённых файлов: 875 добавлений и 719 удалений
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707
net/ieee802154/6lowpan.c
Просмотреть файл

@ -62,9 +62,6 @@
#include "6lowpan.h"
/* TTL uncompression values */
static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
static LIST_HEAD(lowpan_devices);
/* private device info */
@ -135,347 +132,14 @@ static inline void lowpan_raw_dump_table(const char *caller, char *msg,
#endif /* DEBUG */
}
static u8
lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
const unsigned char *lladdr)
{
u8 val = 0;
if (is_addr_mac_addr_based(ipaddr, lladdr))
val = 3; /* 0-bits */
else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
/* compress IID to 16 bits xxxx::XXXX */
memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
*hc06_ptr += 2;
val = 2; /* 16-bits */
} else {
/* do not compress IID => xxxx::IID */
memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
*hc06_ptr += 8;
val = 1; /* 64-bits */
}
return rol8(val, shift);
}
/*
* 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,
const u8 address_mode,
const struct ieee802154_addr *lladdr)
{
bool fail;
switch (address_mode) {
case LOWPAN_IPHC_ADDR_00:
/* for global link addresses */
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_ADDR_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:
/* fe:80::ff:fe00:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
ipaddr->s6_addr[11] = 0xFF;
ipaddr->s6_addr[12] = 0xFE;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
break;
case LOWPAN_IPHC_ADDR_03:
fail = false;
switch (lladdr->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->hwaddr,
IEEE802154_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(lladdr->short_addr);
break;
default:
pr_debug("Invalid addr_type set\n");
return -EINVAL;
}
break;
default:
pr_debug("Invalid address mode value: 0x%x\n", address_mode);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
lowpan_raw_dump_inline(NULL, "Reconstructed ipv6 addr is:\n",
ipaddr->s6_addr, 16);
return 0;
}
/* Uncompress address function for source context
* based address(non-multicast).
*/
static int
lowpan_uncompress_context_based_src_addr(struct sk_buff *skb,
struct in6_addr *ipaddr,
const u8 sam)
{
switch (sam) {
case LOWPAN_IPHC_ADDR_00:
/* unspec address ::
* Do nothing, address is already ::
*/
break;
case LOWPAN_IPHC_ADDR_01:
/* TODO */
case LOWPAN_IPHC_ADDR_02:
/* TODO */
case LOWPAN_IPHC_ADDR_03:
/* TODO */
netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
return -EINVAL;
default:
pr_debug("Invalid sam value: 0x%x\n", sam);
return -EINVAL;
}
lowpan_raw_dump_inline(NULL,
"Reconstructed context based ipv6 src addr is:\n",
ipaddr->s6_addr, 16);
return 0;
}
/* Uncompress function for multicast destination address,
* when M bit is set.
*/
static int
lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
struct in6_addr *ipaddr,
const u8 dam)
{
bool fail;
switch (dam) {
case LOWPAN_IPHC_DAM_00:
/* 00: 128 bits. The full address
* is carried in-line.
*/
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_DAM_01:
/* 01: 48 bits. The address takes
* the form ffXX::00XX:XXXX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
break;
case LOWPAN_IPHC_DAM_10:
/* 10: 32 bits. The address takes
* the form ffXX::00XX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
break;
case LOWPAN_IPHC_DAM_11:
/* 11: 8 bits. The address takes
* the form ff02::00XX.
*/
ipaddr->s6_addr[0] = 0xFF;
ipaddr->s6_addr[1] = 0x02;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
break;
default:
pr_debug("DAM value has a wrong value: 0x%x\n", dam);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
lowpan_raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is:\n",
ipaddr->s6_addr, 16);
return 0;
}
static void
lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
{
struct udphdr *uh = udp_hdr(skb);
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("UDP header: both ports compression to 4 bits\n");
**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("UDP header: remove 8 bits of dest\n");
**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("UDP header: remove 8 bits of source\n");
**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("UDP header: can't compress\n");
**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;
/* skip the UDP header */
skb_pull(skb, sizeof(struct udphdr));
}
static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
{
if (unlikely(!pskb_may_pull(skb, 1)))
return -EINVAL;
*val = skb->data[0];
skb_pull(skb, 1);
return 0;
}
static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
{
if (unlikely(!pskb_may_pull(skb, 2)))
return -EINVAL;
*val = (skb->data[0] << 8) | skb->data[1];
skb_pull(skb, 2);
return 0;
}
static int
lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
{
u8 tmp;
if (!uh)
goto err;
if (lowpan_fetch_skb_u8(skb, &tmp))
goto err;
if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
pr_debug("UDP header uncompression\n");
switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
case LOWPAN_NHC_UDP_CS_P_00:
memcpy(&uh->source, &skb->data[0], 2);
memcpy(&uh->dest, &skb->data[2], 2);
skb_pull(skb, 4);
break;
case LOWPAN_NHC_UDP_CS_P_01:
memcpy(&uh->source, &skb->data[0], 2);
uh->dest =
skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
skb_pull(skb, 3);
break;
case LOWPAN_NHC_UDP_CS_P_10:
uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
memcpy(&uh->dest, &skb->data[1], 2);
skb_pull(skb, 3);
break;
case LOWPAN_NHC_UDP_CS_P_11:
uh->source =
LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
uh->dest =
LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
skb_pull(skb, 1);
break;
default:
pr_debug("ERROR: unknown UDP format\n");
goto err;
}
pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
uh->source, uh->dest);
/* copy checksum */
memcpy(&uh->check, &skb->data[0], 2);
skb_pull(skb, 2);
/*
* UDP lenght needs to be infered from the lower layers
* here, we obtain the hint from the remaining size of the
* frame
*/
uh->len = htons(skb->len + sizeof(struct udphdr));
pr_debug("uncompressed UDP length: src = %d", uh->len);
} else {
pr_debug("ERROR: unsupported NH format\n");
goto err;
}
return 0;
err:
return -EINVAL;
}
static int lowpan_header_create(struct sk_buff *skb,
struct net_device *dev,
unsigned short type, const void *_daddr,
const void *_saddr, unsigned int len)
{
u8 tmp, iphc0, iphc1, *hc06_ptr;
struct ipv6hdr *hdr;
const u8 *saddr = _saddr;
const u8 *daddr = _daddr;
u8 head[100];
struct ieee802154_addr sa, da;
/* TODO:
@ -485,181 +149,14 @@ static int lowpan_header_create(struct sk_buff *skb,
return 0;
hdr = ipv6_hdr(skb);
hc06_ptr = head + 2;
pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
"\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
lowpan_raw_dump_table(__func__, "raw skb network header dump",
skb_network_header(skb), sizeof(struct ipv6hdr));
if (!saddr)
saddr = dev->dev_addr;
lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
/*
* As we copy some bit-length fields, in the IPHC encoding bytes,
* we sometimes use |=
* If the field is 0, and the current bit value in memory is 1,
* this does not work. We therefore reset the IPHC encoding here
*/
iphc0 = LOWPAN_DISPATCH_IPHC;
iphc1 = 0;
/* TODO: context lookup */
lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
/*
* 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
*/
/* hc06 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 */
*hc06_ptr = tmp;
hc06_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;
*hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
hc06_ptr += 3;
} else {
/* compress nothing */
memcpy(hc06_ptr, &hdr, 4);
/* replace the top byte with new ECN | DSCP format */
*hc06_ptr = tmp;
hc06_ptr += 4;
}
}
/* NOTE: payload length is always compressed */
/* Next Header is compress if UDP */
if (hdr->nexthdr == UIP_PROTO_UDP)
iphc0 |= LOWPAN_IPHC_NH_C;
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
*hc06_ptr = hdr->nexthdr;
hc06_ptr += 1;
}
/*
* Hop limit
* if 1: compress, encoding is 01
* if 64: compress, encoding is 10
* if 255: compress, encoding is 11
* else do not compress
*/
switch (hdr->hop_limit) {
case 1:
iphc0 |= LOWPAN_IPHC_TTL_1;
break;
case 64:
iphc0 |= LOWPAN_IPHC_TTL_64;
break;
case 255:
iphc0 |= LOWPAN_IPHC_TTL_255;
break;
default:
*hc06_ptr = hdr->hop_limit;
hc06_ptr += 1;
break;
}
/* source address compression */
if (is_addr_unspecified(&hdr->saddr)) {
pr_debug("source address is unspecified, setting SAC\n");
iphc1 |= LOWPAN_IPHC_SAC;
/* TODO: context lookup */
} else if (is_addr_link_local(&hdr->saddr)) {
pr_debug("source address is link-local\n");
iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
} else {
pr_debug("send the full source address\n");
memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
hc06_ptr += 16;
}
/* destination address compression */
if (is_addr_mcast(&hdr->daddr)) {
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 */
*hc06_ptr = hdr->daddr.s6_addr[15];
hc06_ptr += 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 */
*hc06_ptr = hdr->daddr.s6_addr[1];
memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
hc06_ptr += 4;
} 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 */
*hc06_ptr = hdr->daddr.s6_addr[1];
memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
hc06_ptr += 6;
} else {
pr_debug("using full address\n");
iphc1 |= LOWPAN_IPHC_DAM_00;
memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
hc06_ptr += 16;
}
} else {
/* TODO: context lookup */
if (is_addr_link_local(&hdr->daddr)) {
pr_debug("dest address is unicast and link-local\n");
iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
} else {
pr_debug("dest address is unicast: using full one\n");
memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
hc06_ptr += 16;
}
}
/* UDP header compression */
if (hdr->nexthdr == UIP_PROTO_UDP)
lowpan_compress_udp_header(&hc06_ptr, skb);
head[0] = iphc0;
head[1] = iphc1;
skb_pull(skb, sizeof(struct ipv6hdr));
skb_reset_transport_header(skb);
memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
skb_reset_network_header(skb);
lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
skb->len);
lowpan_header_compress(skb, dev, type, daddr, saddr, len);
/*
* NOTE1: I'm still unsure about the fact that compression and WPAN
@ -671,7 +168,6 @@ static int lowpan_header_create(struct sk_buff *skb,
* from MAC subif of the 'dev' and 'real_dev' network devices, but
* this isn't implemented in mainline yet, so currently we assign 0xff
*/
{
mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
@ -701,9 +197,9 @@ static int lowpan_header_create(struct sk_buff *skb,
return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
type, (void *)&da, (void *)&sa, skb->len);
}
}
static int lowpan_give_skb_to_devices(struct sk_buff *skb)
static int lowpan_give_skb_to_devices(struct sk_buff *skb,
struct net_device *dev)
{
struct lowpan_dev_record *entry;
struct sk_buff *skb_cp;
@ -726,31 +222,6 @@ static int lowpan_give_skb_to_devices(struct sk_buff *skb)
return stat;
}
static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
{
struct sk_buff *new;
int stat = NET_RX_SUCCESS;
new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
GFP_ATOMIC);
kfree_skb(skb);
if (!new)
return -ENOMEM;
skb_push(new, sizeof(struct ipv6hdr));
skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
new->protocol = htons(ETH_P_IPV6);
new->pkt_type = PACKET_HOST;
stat = lowpan_give_skb_to_devices(new);
kfree_skb(new);
return stat;
}
static void lowpan_fragment_timer_expired(unsigned long entry_addr)
{
struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
@ -814,13 +285,10 @@ frame_err:
return NULL;
}
static int
lowpan_process_data(struct sk_buff *skb)
static int process_data(struct sk_buff *skb)
{
struct ipv6hdr hdr = {};
u8 tmp, iphc0, iphc1, num_context = 0;
u8 iphc0, iphc1;
const struct ieee802154_addr *_saddr, *_daddr;
int err;
lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
skb->len);
@ -925,162 +393,11 @@ lowpan_process_data(struct sk_buff *skb)
_saddr = &mac_cb(skb)->sa;
_daddr = &mac_cb(skb)->da;
pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
/* 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_u8(skb, &num_context))
goto drop;
}
hdr.version = 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)
*/
case 0: /* 00b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
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);
break;
/*
* Traffic class carried in-line
* ECN + DSCP (1 byte), Flow Label is elided
*/
case 2: /* 10b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
hdr.priority = ((tmp >> 2) & 0x0f);
hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
break;
/*
* Flow Label carried in-line
* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
*/
case 1: /* 01b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
skb_pull(skb, 2);
break;
/* Traffic Class and Flow Label are elided */
case 3: /* 11b */
break;
default:
break;
}
/* Next Header */
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
/* Next header is carried inline */
if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
goto drop;
pr_debug("NH flag is set, next header carried inline: %02x\n",
hdr.nexthdr);
}
/* Hop Limit */
if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
else {
if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
goto drop;
}
/* 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 = lowpan_uncompress_context_based_src_addr(
skb, &hdr.saddr, tmp);
} else {
/* Source address uncompression */
pr_debug("source address stateless compression\n");
err = lowpan_uncompress_addr(skb, &hdr.saddr, tmp, _saddr);
}
/* Check on error of previous branch */
if (err)
goto drop;
/* 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) {
pr_debug("dest: context-based mcast compression\n");
/* TODO: implement this */
} else {
err = lowpan_uncompress_multicast_daddr(
skb, &hdr.daddr, tmp);
if (err)
goto drop;
}
} else {
pr_debug("dest: stateless compression\n");
err = lowpan_uncompress_addr(skb, &hdr.daddr, tmp, _daddr);
if (err)
goto drop;
}
/* UDP data uncompression */
if (iphc0 & LOWPAN_IPHC_NH_C) {
struct udphdr uh;
struct sk_buff *new;
if (lowpan_uncompress_udp_header(skb, &uh))
goto drop;
/*
* replace the compressed UDP head by the uncompressed UDP
* header
*/
new = skb_copy_expand(skb, sizeof(struct udphdr),
skb_tailroom(skb), GFP_ATOMIC);
kfree_skb(skb);
if (!new)
return -ENOMEM;
skb = new;
skb_push(skb, sizeof(struct udphdr));
skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
lowpan_raw_dump_table(__func__, "raw UDP header dump",
(u8 *)&uh, sizeof(uh));
hdr.nexthdr = UIP_PROTO_UDP;
}
/* Not fragmented package */
hdr.payload_len = htons(skb->len);
pr_debug("skb headroom size = %d, data length = %d\n",
skb_headroom(skb), skb->len);
pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
"nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
sizeof(hdr));
return lowpan_skb_deliver(skb, &hdr);
return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr,
_saddr->addr_type, IEEE802154_ADDR_LEN,
(u8 *)_daddr->hwaddr, _daddr->addr_type,
IEEE802154_ADDR_LEN, iphc0, iphc1,
lowpan_give_skb_to_devices);
unlock_and_drop:
spin_unlock_bh(&flist_lock);
@ -1316,7 +633,7 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
/* Pull off the 1-byte of 6lowpan header. */
skb_pull(local_skb, 1);
lowpan_give_skb_to_devices(local_skb);
lowpan_give_skb_to_devices(local_skb, NULL);
kfree_skb(local_skb);
kfree_skb(skb);
@ -1328,7 +645,7 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
local_skb = skb_clone(skb, GFP_ATOMIC);
if (!local_skb)
goto drop;
lowpan_process_data(local_skb);
process_data(local_skb);
kfree_skb(skb);
break;

32
net/ieee802154/6lowpan.h
Просмотреть файл

@ -232,6 +232,28 @@
dest = 16 bit inline */
#define LOWPAN_NHC_UDP_CS_P_11 0xF3 /* source & dest = 0xF0B + 4bit inline */
static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
{
if (unlikely(!pskb_may_pull(skb, 1)))
return -EINVAL;
*val = skb->data[0];
skb_pull(skb, 1);
return 0;
}
static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
{
if (unlikely(!pskb_may_pull(skb, 2)))
return -EINVAL;
*val = (skb->data[0] << 8) | skb->data[1];
skb_pull(skb, 2);
return 0;
}
static inline bool lowpan_fetch_skb(struct sk_buff *skb,
void *data, const unsigned int len)
{
@ -244,4 +266,14 @@ static inline bool lowpan_fetch_skb(struct sk_buff *skb,
return false;
}
typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
int lowpan_process_data(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, skb_delivery_cb skb_deliver);
int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *_daddr,
const void *_saddr, unsigned int len);
#endif /* __6LOWPAN_H__ */

807
net/ieee802154/6lowpan_iphc.c Normal file
Просмотреть файл

@ -0,0 +1,807 @@
/*
* Copyright 2011, Siemens AG
* written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
/*
* Based on patches from Jon Smirl <jonsmirl@gmail.com>
* Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* Jon's code is based on 6lowpan implementation for Contiki which is:
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <linux/bitops.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <net/ipv6.h>
#include <net/af_ieee802154.h>
#include "6lowpan.h"
/* print data in line */
static inline void raw_dump_inline(const char *caller, char *msg,
unsigned char *buf, int len)
{
if (msg)
pr_debug("%s():%s: ", caller, msg);
print_hex_dump_debug("", DUMP_PREFIX_NONE,
16, 1, buf, len, false);
}
/*
* print data in a table format:
*
* addr: xx xx xx xx xx xx
* addr: xx xx xx xx xx xx
* ...
*/
static inline void raw_dump_table(const char *caller, char *msg,
unsigned char *buf, int len)
{
if (msg)
pr_debug("%s():%s:\n", caller, msg);
print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET,
16, 1, buf, len, false);
}
/*
* Uncompress address function for source and
* destination address(non-multicast).
*
* address_mode is sam value 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)
{
bool fail;
switch (address_mode) {
case LOWPAN_IPHC_ADDR_00:
/* for global link addresses */
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_ADDR_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:
/* fe:80::ff:fe00:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
ipaddr->s6_addr[11] = 0xFF;
ipaddr->s6_addr[12] = 0xFE;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
break;
case LOWPAN_IPHC_ADDR_03:
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));
break;
default:
pr_debug("Invalid addr_type set\n");
return -EINVAL;
}
break;
default:
pr_debug("Invalid address mode value: 0x%x\n", address_mode);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
ipaddr->s6_addr, 16);
return 0;
}
/*
* Uncompress address function for source context
* based address(non-multicast).
*/
static int uncompress_context_based_src_addr(struct sk_buff *skb,
struct in6_addr *ipaddr,
const u8 sam)
{
switch (sam) {
case LOWPAN_IPHC_ADDR_00:
/* unspec address ::
* Do nothing, address is already ::
*/
break;
case LOWPAN_IPHC_ADDR_01:
/* TODO */
case LOWPAN_IPHC_ADDR_02:
/* TODO */
case LOWPAN_IPHC_ADDR_03:
/* TODO */
netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
return -EINVAL;
default:
pr_debug("Invalid sam value: 0x%x\n", sam);
return -EINVAL;
}
raw_dump_inline(NULL,
"Reconstructed context based ipv6 src addr is",
ipaddr->s6_addr, 16);
return 0;
}
static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr,
struct net_device *dev, skb_delivery_cb deliver_skb)
{
struct sk_buff *new;
int stat;
new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
GFP_ATOMIC);
kfree_skb(skb);
if (!new)
return -ENOMEM;
skb_push(new, sizeof(struct ipv6hdr));
skb_reset_network_header(new);
skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
new->protocol = htons(ETH_P_IPV6);
new->pkt_type = PACKET_HOST;
new->dev = dev;
raw_dump_table(__func__, "raw skb data dump before receiving",
new->data, new->len);
stat = deliver_skb(new, dev);
kfree_skb(new);
return stat;
}
/* Uncompress function for multicast destination address,
* when M bit is set.
*/
static int
lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
struct in6_addr *ipaddr,
const u8 dam)
{
bool fail;
switch (dam) {
case LOWPAN_IPHC_DAM_00:
/* 00: 128 bits. The full address
* is carried in-line.
*/
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_DAM_01:
/* 01: 48 bits. The address takes
* the form ffXX::00XX:XXXX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
break;
case LOWPAN_IPHC_DAM_10:
/* 10: 32 bits. The address takes
* the form ffXX::00XX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
break;
case LOWPAN_IPHC_DAM_11:
/* 11: 8 bits. The address takes
* the form ff02::00XX.
*/
ipaddr->s6_addr[0] = 0xFF;
ipaddr->s6_addr[1] = 0x02;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
break;
default:
pr_debug("DAM value has a wrong value: 0x%x\n", dam);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
ipaddr->s6_addr, 16);
return 0;
}
static int
uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
{
u8 tmp;
if (!uh)
goto err;
if (lowpan_fetch_skb_u8(skb, &tmp))
goto err;
if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
pr_debug("UDP header uncompression\n");
switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
case LOWPAN_NHC_UDP_CS_P_00:
memcpy(&uh->source, &skb->data[0], 2);
memcpy(&uh->dest, &skb->data[2], 2);
skb_pull(skb, 4);
break;
case LOWPAN_NHC_UDP_CS_P_01:
memcpy(&uh->source, &skb->data[0], 2);
uh->dest =
skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
skb_pull(skb, 3);
break;
case LOWPAN_NHC_UDP_CS_P_10:
uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
memcpy(&uh->dest, &skb->data[1], 2);
skb_pull(skb, 3);
break;
case LOWPAN_NHC_UDP_CS_P_11:
uh->source =
LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
uh->dest =
LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
skb_pull(skb, 1);
break;
default:
pr_debug("ERROR: unknown UDP format\n");
goto err;
break;
}
pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
uh->source, uh->dest);
/* copy checksum */
memcpy(&uh->check, &skb->data[0], 2);
skb_pull(skb, 2);
/*
* UDP lenght needs to be infered from the lower layers
* here, we obtain the hint from the remaining size of the
* frame
*/
uh->len = htons(skb->len + sizeof(struct udphdr));
pr_debug("uncompressed UDP length: src = %d", uh->len);
} else {
pr_debug("ERROR: unsupported NH format\n");
goto err;
}
return 0;
err:
return -EINVAL;
}
/* TTL uncompression values */
static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
int lowpan_process_data(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, skb_delivery_cb deliver_skb)
{
struct ipv6hdr hdr = {};
u8 tmp, num_context = 0;
int err;
raw_dump_table(__func__, "raw skb data dump uncompressed",
skb->data, skb->len);
/* 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_u8(skb, &num_context))
goto drop;
}
hdr.version = 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)
*/
case 0: /* 00b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
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);
break;
/*
* Traffic class carried in-line
* ECN + DSCP (1 byte), Flow Label is elided
*/
case 2: /* 10b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
hdr.priority = ((tmp >> 2) & 0x0f);
hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
break;
/*
* Flow Label carried in-line
* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
*/
case 1: /* 01b */
if (lowpan_fetch_skb_u8(skb, &tmp))
goto drop;
hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
skb_pull(skb, 2);
break;
/* Traffic Class and Flow Label are elided */
case 3: /* 11b */
break;
default:
break;
}
/* Next Header */
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
/* Next header is carried inline */
if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
goto drop;
pr_debug("NH flag is set, next header carried inline: %02x\n",
hdr.nexthdr);
}
/* Hop Limit */
if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
else {
if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
goto drop;
}
/* 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);
} else {
/* Source address uncompression */
pr_debug("source address stateless compression\n");
err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
saddr_type, saddr_len);
}
/* Check on error of previous branch */
if (err)
goto drop;
/* 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) {
pr_debug("dest: context-based mcast compression\n");
/* TODO: implement this */
} else {
err = lowpan_uncompress_multicast_daddr(
skb, &hdr.daddr, tmp);
if (err)
goto drop;
}
} else {
err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
daddr_type, daddr_len);
pr_debug("dest: stateless compression mode %d dest %pI6c\n",
tmp, &hdr.daddr);
if (err)
goto drop;
}
/* UDP data uncompression */
if (iphc0 & LOWPAN_IPHC_NH_C) {
struct udphdr uh;
struct sk_buff *new;
if (uncompress_udp_header(skb, &uh))
goto drop;
/*
* replace the compressed UDP head by the uncompressed UDP
* header
*/
new = skb_copy_expand(skb, sizeof(struct udphdr),
skb_tailroom(skb), GFP_ATOMIC);
kfree_skb(skb);
if (!new)
return -ENOMEM;
skb = new;
skb_push(skb, sizeof(struct udphdr));
skb_reset_transport_header(skb);
skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
raw_dump_table(__func__, "raw UDP header dump",
(u8 *)&uh, sizeof(uh));
hdr.nexthdr = UIP_PROTO_UDP;
}
hdr.payload_len = htons(skb->len);
pr_debug("skb headroom size = %d, data length = %d\n",
skb_headroom(skb), skb->len);
pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
"nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
hdr.hop_limit, &hdr.daddr);
raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
sizeof(hdr));
return skb_deliver(skb, &hdr, dev, deliver_skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(lowpan_process_data);
static u8 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift,
const struct in6_addr *ipaddr,
const unsigned char *lladdr)
{
u8 val = 0;
if (is_addr_mac_addr_based(ipaddr, lladdr)) {
val = 3; /* 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 */
memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
*hc06_ptr += 2;
val = 2; /* 16-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
*hc06_ptr - 2, 2);
} else {
/* do not compress IID => xxxx::IID */
memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
*hc06_ptr += 8;
val = 1; /* 64-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
*hc06_ptr - 8, 8);
}
return rol8(val, shift);
}
static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
{
struct udphdr *uh = udp_hdr(skb);
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("UDP header: both ports compression to 4 bits\n");
**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("UDP header: remove 8 bits of dest\n");
**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("UDP header: remove 8 bits of source\n");
**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("UDP header: can't compress\n");
**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;
/* skip the UDP header */
skb_pull(skb, sizeof(struct udphdr));
}
int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *_daddr,
const void *_saddr, unsigned int len)
{
u8 tmp, iphc0, iphc1, *hc06_ptr;
struct ipv6hdr *hdr;
u8 head[100] = {};
if (type != ETH_P_IPV6)
return -EINVAL;
hdr = ipv6_hdr(skb);
hc06_ptr = head + 2;
pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
"\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
hdr->hop_limit, &hdr->daddr);
raw_dump_table(__func__, "raw skb network header dump",
skb_network_header(skb), sizeof(struct ipv6hdr));
/*
* As we copy some bit-length fields, in the IPHC encoding bytes,
* we sometimes use |=
* If the field is 0, and the current bit value in memory is 1,
* this does not work. We therefore reset the IPHC encoding here
*/
iphc0 = LOWPAN_DISPATCH_IPHC;
iphc1 = 0;
/* 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_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
*/
/* hc06 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 */
*hc06_ptr = tmp;
hc06_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;
*hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
hc06_ptr += 3;
} else {
/* compress nothing */
memcpy(hc06_ptr, &hdr, 4);
/* replace the top byte with new ECN | DSCP format */
*hc06_ptr = tmp;
hc06_ptr += 4;
}
}
/* NOTE: payload length is always compressed */
/* Next Header is compress if UDP */
if (hdr->nexthdr == UIP_PROTO_UDP)
iphc0 |= LOWPAN_IPHC_NH_C;
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
*hc06_ptr = hdr->nexthdr;
hc06_ptr += 1;
}
/*
* Hop limit
* if 1: compress, encoding is 01
* if 64: compress, encoding is 10
* if 255: compress, encoding is 11
* else do not compress
*/
switch (hdr->hop_limit) {
case 1:
iphc0 |= LOWPAN_IPHC_TTL_1;
break;
case 64:
iphc0 |= LOWPAN_IPHC_TTL_64;
break;
case 255:
iphc0 |= LOWPAN_IPHC_TTL_255;
break;
default:
*hc06_ptr = hdr->hop_limit;
hc06_ptr += 1;
break;
}
/* source address compression */
if (is_addr_unspecified(&hdr->saddr)) {
pr_debug("source address is unspecified, setting SAC\n");
iphc1 |= LOWPAN_IPHC_SAC;
/* TODO: context lookup */
} else if (is_addr_link_local(&hdr->saddr)) {
iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
LOWPAN_IPHC_SAM_BIT, &hdr->saddr, _saddr);
pr_debug("source address unicast link-local %pI6c "
"iphc1 0x%02x\n", &hdr->saddr, iphc1);
} else {
pr_debug("send the full source address\n");
memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
hc06_ptr += 16;
}
/* destination address compression */
if (is_addr_mcast(&hdr->daddr)) {
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 */
*hc06_ptr = hdr->daddr.s6_addr[15];
hc06_ptr += 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 */
*hc06_ptr = hdr->daddr.s6_addr[1];
memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
hc06_ptr += 4;
} 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 */
*hc06_ptr = hdr->daddr.s6_addr[1];
memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
hc06_ptr += 6;
} else {
pr_debug("using full address\n");
iphc1 |= LOWPAN_IPHC_DAM_00;
memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
hc06_ptr += 16;
}
} else {
/* TODO: context lookup */
if (is_addr_link_local(&hdr->daddr)) {
iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
pr_debug("dest address unicast link-local %pI6c "
"iphc1 0x%02x\n", &hdr->daddr, iphc1);
} else {
pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
hc06_ptr += 16;
}
}
/* UDP header compression */
if (hdr->nexthdr == UIP_PROTO_UDP)
compress_udp_header(&hc06_ptr, skb);
head[0] = iphc0;
head[1] = iphc1;
skb_pull(skb, sizeof(struct ipv6hdr));
skb_reset_transport_header(skb);
memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
skb_reset_network_header(skb);
pr_debug("header len %d skb %u\n", (int)(hc06_ptr - head), skb->len);
raw_dump_table(__func__, "raw skb data dump compressed",
skb->data, skb->len);
return 0;
}
EXPORT_SYMBOL_GPL(lowpan_header_compress);

2
net/ieee802154/Makefile
Просмотреть файл

@ -1,5 +1,5 @@
obj-$(CONFIG_IEEE802154) += ieee802154.o af_802154.o
obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o
obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o 6lowpan_iphc.o
ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o wpan-class.o
af_802154-y := af_ieee802154.o raw.o dgram.o