8788a1ee07
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
331 lines
10 KiB
C
331 lines
10 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef __6LOWPAN_H__
|
|
#define __6LOWPAN_H__
|
|
|
|
#include <linux/debugfs.h>
|
|
|
|
#include <net/ipv6.h>
|
|
#include <net/net_namespace.h>
|
|
|
|
/* special link-layer handling */
|
|
#include <net/mac802154.h>
|
|
|
|
#define EUI64_ADDR_LEN 8
|
|
|
|
#define LOWPAN_NHC_MAX_ID_LEN 1
|
|
/* Maximum next header compression length which we currently support inclusive
|
|
* possible inline data.
|
|
*/
|
|
#define LOWPAN_NHC_MAX_HDR_LEN (sizeof(struct udphdr))
|
|
/* Max IPHC Header len without IPv6 hdr specific inline data.
|
|
* Useful for getting the "extra" bytes we need at worst case compression.
|
|
*
|
|
* LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
|
|
*/
|
|
#define LOWPAN_IPHC_MAX_HEADER_LEN (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
|
|
/* Maximum worst case IPHC header buffer size */
|
|
#define LOWPAN_IPHC_MAX_HC_BUF_LEN (sizeof(struct ipv6hdr) + \
|
|
LOWPAN_IPHC_MAX_HEADER_LEN + \
|
|
LOWPAN_NHC_MAX_HDR_LEN)
|
|
/* SCI/DCI is 4 bit width, so we have maximum 16 entries */
|
|
#define LOWPAN_IPHC_CTX_TABLE_SIZE (1 << 4)
|
|
|
|
#define LOWPAN_DISPATCH_IPV6 0x41 /* 01000001 = 65 */
|
|
#define LOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx = ... */
|
|
#define LOWPAN_DISPATCH_IPHC_MASK 0xe0
|
|
|
|
static inline bool lowpan_is_ipv6(u8 dispatch)
|
|
{
|
|
return dispatch == LOWPAN_DISPATCH_IPV6;
|
|
}
|
|
|
|
static inline bool lowpan_is_iphc(u8 dispatch)
|
|
{
|
|
return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
|
|
}
|
|
|
|
#define LOWPAN_PRIV_SIZE(llpriv_size) \
|
|
(sizeof(struct lowpan_dev) + llpriv_size)
|
|
|
|
enum lowpan_lltypes {
|
|
LOWPAN_LLTYPE_BTLE,
|
|
LOWPAN_LLTYPE_IEEE802154,
|
|
};
|
|
|
|
enum lowpan_iphc_ctx_flags {
|
|
LOWPAN_IPHC_CTX_FLAG_ACTIVE,
|
|
LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
|
|
};
|
|
|
|
struct lowpan_iphc_ctx {
|
|
u8 id;
|
|
struct in6_addr pfx;
|
|
u8 plen;
|
|
unsigned long flags;
|
|
};
|
|
|
|
struct lowpan_iphc_ctx_table {
|
|
spinlock_t lock;
|
|
const struct lowpan_iphc_ctx_ops *ops;
|
|
struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
|
|
};
|
|
|
|
static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
|
|
{
|
|
return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
|
|
}
|
|
|
|
static inline bool
|
|
lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
|
|
{
|
|
return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
|
|
}
|
|
|
|
struct lowpan_dev {
|
|
enum lowpan_lltypes lltype;
|
|
struct dentry *iface_debugfs;
|
|
struct lowpan_iphc_ctx_table ctx;
|
|
|
|
/* must be last */
|
|
u8 priv[] __aligned(sizeof(void *));
|
|
};
|
|
|
|
struct lowpan_802154_neigh {
|
|
__le16 short_addr;
|
|
};
|
|
|
|
static inline
|
|
struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
|
|
{
|
|
return neigh_priv;
|
|
}
|
|
|
|
static inline
|
|
struct lowpan_dev *lowpan_dev(const struct net_device *dev)
|
|
{
|
|
return netdev_priv(dev);
|
|
}
|
|
|
|
/* private device info */
|
|
struct lowpan_802154_dev {
|
|
struct net_device *wdev; /* wpan device ptr */
|
|
u16 fragment_tag;
|
|
};
|
|
|
|
static inline struct
|
|
lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
|
|
{
|
|
return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
|
|
}
|
|
|
|
struct lowpan_802154_cb {
|
|
u16 d_tag;
|
|
unsigned int d_size;
|
|
u8 d_offset;
|
|
};
|
|
|
|
static inline
|
|
struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
|
|
{
|
|
BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
|
|
return (struct lowpan_802154_cb *)skb->cb;
|
|
}
|
|
|
|
static inline void lowpan_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 lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
|
|
const void *lladdr)
|
|
{
|
|
/* fe:80::XXXX:XXff:feXX:XXXX
|
|
* \_________________/
|
|
* hwaddr
|
|
*/
|
|
ipaddr->s6_addr[0] = 0xFE;
|
|
ipaddr->s6_addr[1] = 0x80;
|
|
memcpy(&ipaddr->s6_addr[8], lladdr, 3);
|
|
ipaddr->s6_addr[11] = 0xFF;
|
|
ipaddr->s6_addr[12] = 0xFE;
|
|
memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
/* print data in line */
|
|
static inline void raw_dump_inline(const char *caller, char *msg,
|
|
const 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,
|
|
const 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);
|
|
}
|
|
#else
|
|
static inline void raw_dump_table(const char *caller, char *msg,
|
|
const unsigned char *buf, int len) { }
|
|
static inline void raw_dump_inline(const char *caller, char *msg,
|
|
const unsigned char *buf, int len) { }
|
|
#endif
|
|
|
|
/**
|
|
* lowpan_fetch_skb - getting inline data from 6LoWPAN header
|
|
*
|
|
* This function will pull data from sk buffer and put it into data to
|
|
* remove the 6LoWPAN inline data. This function returns true if the
|
|
* sk buffer is too small to pull the amount of data which is specified
|
|
* by len.
|
|
*
|
|
* @skb: the buffer where the inline data should be pulled from.
|
|
* @data: destination buffer for the inline data.
|
|
* @len: amount of data which should be pulled in bytes.
|
|
*/
|
|
static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
|
|
unsigned int len)
|
|
{
|
|
if (unlikely(!pskb_may_pull(skb, len)))
|
|
return true;
|
|
|
|
skb_copy_from_linear_data(skb, data, len);
|
|
skb_pull(skb, len);
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool lowpan_802154_is_valid_src_short_addr(__le16 addr)
|
|
{
|
|
/* First bit of addr is multicast, reserved or 802.15.4 specific */
|
|
return !(addr & cpu_to_le16(0x8000));
|
|
}
|
|
|
|
static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
|
|
const size_t len)
|
|
{
|
|
memcpy(*hc_ptr, data, len);
|
|
*hc_ptr += len;
|
|
}
|
|
|
|
int lowpan_register_netdevice(struct net_device *dev,
|
|
enum lowpan_lltypes lltype);
|
|
int lowpan_register_netdev(struct net_device *dev,
|
|
enum lowpan_lltypes lltype);
|
|
void lowpan_unregister_netdevice(struct net_device *dev);
|
|
void lowpan_unregister_netdev(struct net_device *dev);
|
|
|
|
/**
|
|
* lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
|
|
*
|
|
* This function replaces the IPHC 6LoWPAN header which should be pointed at
|
|
* skb->data and skb_network_header, with the IPv6 header.
|
|
* It would be nice that the caller have the necessary headroom of IPv6 header
|
|
* and greatest Transport layer header, this would reduce the overhead for
|
|
* reallocate headroom.
|
|
*
|
|
* @skb: the buffer which should be manipulate.
|
|
* @dev: the lowpan net device pointer.
|
|
* @daddr: destination lladdr of mac header which is used for compression
|
|
* methods.
|
|
* @saddr: source lladdr of mac header which is used for compression
|
|
* methods.
|
|
*/
|
|
int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
|
|
const void *daddr, const void *saddr);
|
|
|
|
/**
|
|
* lowpan_header_compress - replace IPv6 header with 6LoWPAN header
|
|
*
|
|
* This function replaces the IPv6 header which should be pointed at
|
|
* skb->data and skb_network_header, with the IPHC 6LoWPAN header.
|
|
* The caller need to be sure that the sk buffer is not shared and at have
|
|
* at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
|
|
* which is the IPHC "more bytes than IPv6 header" at worst case.
|
|
*
|
|
* @skb: the buffer which should be manipulate.
|
|
* @dev: the lowpan net device pointer.
|
|
* @daddr: destination lladdr of mac header which is used for compression
|
|
* methods.
|
|
* @saddr: source lladdr of mac header which is used for compression
|
|
* methods.
|
|
*/
|
|
int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
|
|
const void *daddr, const void *saddr);
|
|
|
|
#endif /* __6LOWPAN_H__ */
|