net/6lowpan/ndisc.c - linux - Git at Google

 /* 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
 };
	/* 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
	};