Commit bbe5f5ce authored by Alexander Aring's avatar Alexander Aring Committed by David S. Miller
Browse files

6lowpan: introduce 6lowpan-nd 



This patch introduce different 6lowpan handling for receive and transmit
NS/NA messages for the ipv6 neighbour discovery. The first use-case is
for supporting 802.15.4 short addresses inside the option fields and
handling for RFC6775 6CO option field as userspace option.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: default avatarStefan Schmidt <stefan@osg.samsung.com>
Acked-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarAlexander Aring <aar@pengutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cc84b3c6

include/net/ndisc.h

+12 −6
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ enum { 
	ND_OPT_ROUTE_INFO = 24,		/* RFC4191 */

	ND_OPT_RDNSS = 25,		/* RFC5006 */

	ND_OPT_DNSSL = 31,		/* RFC6106 */

	ND_OPT_6CO = 34,		/* RFC6775 */

	__ND_OPT_MAX

};
@@ -109,6 +110,9 @@ struct ndisc_options { 
#endif

	struct nd_opt_hdr *nd_useropts;

	struct nd_opt_hdr *nd_useropts_end;

#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)

	struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];

#endif

};



#define nd_opts_src_lladdr		nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
@@ -117,6 +121,8 @@ struct ndisc_options { 
#define nd_opts_pi_end			nd_opt_array[__ND_OPT_PREFIX_INFO_END]

#define nd_opts_rh			nd_opt_array[ND_OPT_REDIRECT_HDR]

#define nd_opts_mtu			nd_opt_array[ND_OPT_MTU]

#define nd_802154_opts_src_lladdr	nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]

#define nd_802154_opts_tgt_lladdr	nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]



#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)

net/6lowpan/6lowpan_i.h

+4 −0
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ static inline bool lowpan_is_ll(const struct net_device *dev, 
	return lowpan_dev(dev)->lltype == lltype;

}



extern const struct ndisc_ops lowpan_ndisc_ops;



int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev);



#ifdef CONFIG_6LOWPAN_DEBUGFS

int lowpan_dev_debugfs_init(struct net_device *dev);

void lowpan_dev_debugfs_exit(struct net_device *dev);

net/6lowpan/Makefile

+1 −1
Original line number Diff line number Diff line 
obj-$(CONFIG_6LOWPAN) += 6lowpan.o



6lowpan-y := core.o iphc.o nhc.o

6lowpan-y := core.o iphc.o nhc.o ndisc.o

6lowpan-$(CONFIG_6LOWPAN_DEBUGFS) += debugfs.o



#rfc6282 nhcs

net/6lowpan/core.c

+3 −1
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ int lowpan_register_netdevice(struct net_device *dev, 
	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)

		lowpan_dev(dev)->ctx.table[i].id = i;



	dev->ndisc_ops = &lowpan_ndisc_ops;



	ret = register_netdevice(dev);

	if (ret < 0)

		return ret;
@@ -73,7 +75,7 @@ void lowpan_unregister_netdev(struct net_device *dev) 
}

EXPORT_SYMBOL(lowpan_unregister_netdev);



static int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)

int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)

{

	struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;

net/6lowpan/ndisc.c

0 → 100644
+234 −0
Original line number Diff line number Diff line 
/* 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)

{

	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);

	else

		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;

		}

		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

};

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