linux/net/6lowpan/ndisc.c
Alexander Aring 5ddedce3b7 6lowpan: ndisc: no overreact if no short address is available
This patch removes handling to remove short address for a neigbour entry
if RS/RA/NS/NA doesn't contain a short address. If these messages
doesn't has any short address option, the existing short address from
ndisc cache will be used. The current behaviour will set that the
neigbour doesn't has a short address anymore.

Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2016-09-19 20:19:34 +02:00

240 lines
6.7 KiB
C

/* 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.
*
* Authors:
* (C) 2016 Pengutronix, Alexander Aring <aar@pengutronix.de>
*/
#include <net/6lowpan.h>
#include <net/addrconf.h>
#include <net/ndisc.h>
#include "6lowpan_i.h"
static int lowpan_ndisc_is_useropt(u8 nd_opt_type)
{
return nd_opt_type == ND_OPT_6CO;
}
#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
#define NDISC_802154_SHORT_ADDR_LENGTH 1
static int lowpan_ndisc_parse_802154_options(const struct net_device *dev,
struct nd_opt_hdr *nd_opt,
struct ndisc_options *ndopts)
{
switch (nd_opt->nd_opt_len) {
case NDISC_802154_SHORT_ADDR_LENGTH:
if (ndopts->nd_802154_opt_array[nd_opt->nd_opt_type])
ND_PRINTK(2, warn,
"%s: duplicated short addr ND6 option found: type=%d\n",
__func__, nd_opt->nd_opt_type);
else
ndopts->nd_802154_opt_array[nd_opt->nd_opt_type] = nd_opt;
return 1;
default:
/* all others will be handled by ndisc IPv6 option parsing */
return 0;
}
}
static int lowpan_ndisc_parse_options(const struct net_device *dev,
struct nd_opt_hdr *nd_opt,
struct ndisc_options *ndopts)
{
if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
return 0;
switch (nd_opt->nd_opt_type) {
case ND_OPT_SOURCE_LL_ADDR:
case ND_OPT_TARGET_LL_ADDR:
return lowpan_ndisc_parse_802154_options(dev, nd_opt, ndopts);
default:
return 0;
}
}
static void lowpan_ndisc_802154_update(struct neighbour *n, u32 flags,
u8 icmp6_type,
const struct ndisc_options *ndopts)
{
struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
u8 *lladdr_short = NULL;
switch (icmp6_type) {
case NDISC_ROUTER_SOLICITATION:
case NDISC_ROUTER_ADVERTISEMENT:
case NDISC_NEIGHBOUR_SOLICITATION:
if (ndopts->nd_802154_opts_src_lladdr) {
lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_src_lladdr,
IEEE802154_SHORT_ADDR_LEN, 0);
if (!lladdr_short) {
ND_PRINTK(2, warn,
"NA: invalid short link-layer address length\n");
return;
}
}
break;
case NDISC_REDIRECT:
case NDISC_NEIGHBOUR_ADVERTISEMENT:
if (ndopts->nd_802154_opts_tgt_lladdr) {
lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_tgt_lladdr,
IEEE802154_SHORT_ADDR_LEN, 0);
if (!lladdr_short) {
ND_PRINTK(2, warn,
"NA: invalid short link-layer address length\n");
return;
}
}
break;
default:
break;
}
write_lock_bh(&n->lock);
if (lladdr_short) {
ieee802154_be16_to_le16(&neigh->short_addr, lladdr_short);
if (!lowpan_802154_is_valid_src_short_addr(neigh->short_addr))
neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
}
write_unlock_bh(&n->lock);
}
static void lowpan_ndisc_update(const struct net_device *dev,
struct neighbour *n, u32 flags, u8 icmp6_type,
const struct ndisc_options *ndopts)
{
if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
return;
/* react on overrides only. TODO check if this is really right. */
if (flags & NEIGH_UPDATE_F_OVERRIDE)
lowpan_ndisc_802154_update(n, flags, icmp6_type, ndopts);
}
static int lowpan_ndisc_opt_addr_space(const struct net_device *dev,
u8 icmp6_type, struct neighbour *neigh,
u8 *ha_buf, u8 **ha)
{
struct lowpan_802154_neigh *n;
struct wpan_dev *wpan_dev;
int addr_space = 0;
if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
return 0;
switch (icmp6_type) {
case NDISC_REDIRECT:
n = lowpan_802154_neigh(neighbour_priv(neigh));
read_lock_bh(&neigh->lock);
if (lowpan_802154_is_valid_src_short_addr(n->short_addr)) {
memcpy(ha_buf, &n->short_addr,
IEEE802154_SHORT_ADDR_LEN);
read_unlock_bh(&neigh->lock);
addr_space += __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
*ha = ha_buf;
} else {
read_unlock_bh(&neigh->lock);
}
break;
case NDISC_NEIGHBOUR_ADVERTISEMENT:
case NDISC_NEIGHBOUR_SOLICITATION:
case NDISC_ROUTER_SOLICITATION:
wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
addr_space = __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
break;
default:
break;
}
return addr_space;
}
static void lowpan_ndisc_fill_addr_option(const struct net_device *dev,
struct sk_buff *skb, u8 icmp6_type,
const u8 *ha)
{
struct wpan_dev *wpan_dev;
__be16 short_addr;
u8 opt_type;
if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
return;
switch (icmp6_type) {
case NDISC_REDIRECT:
if (ha) {
ieee802154_le16_to_be16(&short_addr, ha);
__ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
&short_addr,
IEEE802154_SHORT_ADDR_LEN, 0);
}
return;
case NDISC_NEIGHBOUR_ADVERTISEMENT:
opt_type = ND_OPT_TARGET_LL_ADDR;
break;
case NDISC_ROUTER_SOLICITATION:
case NDISC_NEIGHBOUR_SOLICITATION:
opt_type = ND_OPT_SOURCE_LL_ADDR;
break;
default:
return;
}
wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
ieee802154_le16_to_be16(&short_addr,
&wpan_dev->short_addr);
__ndisc_fill_addr_option(skb, opt_type, &short_addr,
IEEE802154_SHORT_ADDR_LEN, 0);
}
}
static void lowpan_ndisc_prefix_rcv_add_addr(struct net *net,
struct net_device *dev,
const struct prefix_info *pinfo,
struct inet6_dev *in6_dev,
struct in6_addr *addr,
int addr_type, u32 addr_flags,
bool sllao, bool tokenized,
__u32 valid_lft,
u32 prefered_lft,
bool dev_addr_generated)
{
int err;
/* generates short based address for RA PIO's */
if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) && dev_addr_generated &&
!addrconf_ifid_802154_6lowpan(addr->s6_addr + 8, dev)) {
err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
addr, addr_type, addr_flags,
sllao, tokenized, valid_lft,
prefered_lft);
if (err)
ND_PRINTK(2, warn,
"RA: could not add a short address based address for prefix: %pI6c\n",
&pinfo->prefix);
}
}
#endif
const struct ndisc_ops lowpan_ndisc_ops = {
.is_useropt = lowpan_ndisc_is_useropt,
#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
.parse_options = lowpan_ndisc_parse_options,
.update = lowpan_ndisc_update,
.opt_addr_space = lowpan_ndisc_opt_addr_space,
.fill_addr_option = lowpan_ndisc_fill_addr_option,
.prefix_rcv_add_addr = lowpan_ndisc_prefix_rcv_add_addr,
#endif
};