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6lowpan.c
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6lowpan.c
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/*
* Copyright 2011, Siemens AG
* written by Alexander Smirnov <[email protected]>
*/
/*
* Based on patches from Jon Smirl <[email protected]>
* Copyright (c) 2011 Jon Smirl <[email protected]>
*
* 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/module.h>
#include <linux/moduleparam.h>
#include <linux/netdevice.h>
#include <net/af_ieee802154.h>
#include <net/ieee802154.h>
#include <net/ieee802154_netdev.h>
#include <net/ipv6.h>
#include "6lowpan.h"
/* TTL uncompression values */
static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
static LIST_HEAD(lowpan_devices);
/* private device info */
struct lowpan_dev_info {
struct net_device *real_dev; /* real WPAN device ptr */
struct mutex dev_list_mtx; /* mutex for list ops */
unsigned short fragment_tag;
};
struct lowpan_dev_record {
struct net_device *ldev;
struct list_head list;
};
struct lowpan_fragment {
struct sk_buff *skb; /* skb to be assembled */
u16 length; /* length to be assemled */
u32 bytes_rcv; /* bytes received */
u16 tag; /* current fragment tag */
struct timer_list timer; /* assembling timer */
struct list_head list; /* fragments list */
};
static LIST_HEAD(lowpan_fragments);
static DEFINE_SPINLOCK(flist_lock);
static inline struct
lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
{
return netdev_priv(dev);
}
static inline void lowpan_address_flip(u8 *src, u8 *dest)
{
int i;
for (i = 0; i < IEEE802154_ADDR_LEN; i++)
(dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
}
/* list of all 6lowpan devices, uses for package delivering */
/* print data in line */
static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
unsigned char *buf, int len)
{
#ifdef DEBUG
if (msg)
pr_debug("(%s) %s: ", caller, msg);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
16, 1, buf, len, false);
#endif /* DEBUG */
}
/*
* print data in a table format:
*
* addr: xx xx xx xx xx xx
* addr: xx xx xx xx xx xx
* ...
*/
static inline void lowpan_raw_dump_table(const char *caller, char *msg,
unsigned char *buf, int len)
{
#ifdef DEBUG
if (msg)
pr_debug("(%s) %s:\n", caller, msg);
print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
16, 1, buf, len, false);
#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:
* if this package isn't ipv6 one, where should it be routed?
*/
if (type != ETH_P_IPV6)
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);
/*
* NOTE1: I'm still unsure about the fact that compression and WPAN
* header are created here and not later in the xmit. So wait for
* an opinion of net maintainers.
*/
/*
* NOTE2: to be absolutely correct, we must derive PANid information
* 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);
/* prepare wpan address data */
sa.addr_type = IEEE802154_ADDR_LONG;
sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
memcpy(&(sa.hwaddr), saddr, 8);
/* intra-PAN communications */
da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
/*
* if the destination address is the broadcast address, use the
* corresponding short address
*/
if (lowpan_is_addr_broadcast(daddr)) {
da.addr_type = IEEE802154_ADDR_SHORT;
da.short_addr = IEEE802154_ADDR_BROADCAST;
} else {
da.addr_type = IEEE802154_ADDR_LONG;
memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
/* request acknowledgment */
mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
}
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)
{
struct lowpan_dev_record *entry;
struct sk_buff *skb_cp;
int stat = NET_RX_SUCCESS;
rcu_read_lock();
list_for_each_entry_rcu(entry, &lowpan_devices, list)
if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
skb_cp = skb_copy(skb, GFP_ATOMIC);
if (!skb_cp) {
stat = -ENOMEM;
break;
}
skb_cp->dev = entry->ldev;
stat = netif_rx(skb_cp);
}
rcu_read_unlock();
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;
pr_debug("timer expired for frame with tag %d\n", entry->tag);
list_del(&entry->list);
dev_kfree_skb(entry->skb);
kfree(entry);
}
static struct lowpan_fragment *
lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
{
struct lowpan_fragment *frame;
frame = kzalloc(sizeof(struct lowpan_fragment),
GFP_ATOMIC);
if (!frame)
goto frame_err;
INIT_LIST_HEAD(&frame->list);
frame->length = len;
frame->tag = tag;
/* allocate buffer for frame assembling */
frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
sizeof(struct ipv6hdr));
if (!frame->skb)
goto skb_err;
frame->skb->priority = skb->priority;
/* reserve headroom for uncompressed ipv6 header */
skb_reserve(frame->skb, sizeof(struct ipv6hdr));
skb_put(frame->skb, frame->length);
/* copy the first control block to keep a
* trace of the link-layer addresses in case
* of a link-local compressed address
*/
memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb));
init_timer(&frame->timer);
/* time out is the same as for ipv6 - 60 sec */
frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
frame->timer.data = (unsigned long)frame;
frame->timer.function = lowpan_fragment_timer_expired;
add_timer(&frame->timer);
list_add_tail(&frame->list, &lowpan_fragments);
return frame;
skb_err:
kfree(frame);
frame_err:
return NULL;
}
static int
lowpan_process_data(struct sk_buff *skb)
{
struct ipv6hdr hdr = {};
u8 tmp, iphc0, iphc1, num_context = 0;
const struct ieee802154_addr *_saddr, *_daddr;
int err;
lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
skb->len);
/* at least two bytes will be used for the encoding */
if (skb->len < 2)
goto drop;
if (lowpan_fetch_skb_u8(skb, &iphc0))
goto drop;
/* fragments assembling */
switch (iphc0 & LOWPAN_DISPATCH_MASK) {
case LOWPAN_DISPATCH_FRAG1:
case LOWPAN_DISPATCH_FRAGN:
{
struct lowpan_fragment *frame;
/* slen stores the rightmost 8 bits of the 11 bits length */
u8 slen, offset = 0;
u16 len, tag;
bool found = false;
if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */
goto drop;
/* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
len = ((iphc0 & 7) << 8) | slen;
if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
pr_debug("%s received a FRAG1 packet (tag: %d, "
"size of the entire IP packet: %d)",
__func__, tag, len);
} else { /* FRAGN */
if (lowpan_fetch_skb_u8(skb, &offset))
goto unlock_and_drop;
pr_debug("%s received a FRAGN packet (tag: %d, "
"size of the entire IP packet: %d, "
"offset: %d)", __func__, tag, len, offset * 8);
}
/*
* check if frame assembling with the same tag is
* already in progress
*/
spin_lock_bh(&flist_lock);
list_for_each_entry(frame, &lowpan_fragments, list)
if (frame->tag == tag) {
found = true;
break;
}
/* alloc new frame structure */
if (!found) {
pr_debug("%s first fragment received for tag %d, "
"begin packet reassembly", __func__, tag);
frame = lowpan_alloc_new_frame(skb, len, tag);
if (!frame)
goto unlock_and_drop;
}
/* if payload fits buffer, copy it */
if (likely((offset * 8 + skb->len) <= frame->length))
skb_copy_to_linear_data_offset(frame->skb, offset * 8,
skb->data, skb->len);
else
goto unlock_and_drop;
frame->bytes_rcv += skb->len;
/* frame assembling complete */
if ((frame->bytes_rcv == frame->length) &&
frame->timer.expires > jiffies) {
/* if timer haven't expired - first of all delete it */
del_timer_sync(&frame->timer);
list_del(&frame->list);
spin_unlock_bh(&flist_lock);
pr_debug("%s successfully reassembled fragment "
"(tag %d)", __func__, tag);
dev_kfree_skb(skb);
skb = frame->skb;
kfree(frame);
if (lowpan_fetch_skb_u8(skb, &iphc0))
goto drop;
break;
}
spin_unlock_bh(&flist_lock);
return kfree_skb(skb), 0;
}
default:
break;
}
if (lowpan_fetch_skb_u8(skb, &iphc1))
goto drop;
_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;