ipv6: introduce neighbour discovery ops

This patch introduces neighbour discovery ops callback structure. The
idea is to separate the handling for 6LoWPAN into the 6lowpan module.

These callback offers 6lowpan different handling, such as 802.15.4 short
address handling or RFC6775 (Neighbor Discovery Optimization for IPv6
over 6LoWPANs).

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>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 32 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index a7b9468e684a..2f4afd17954b 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -172,10 +172,19 @@ static void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 }
 
 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
-					  void *data)
+					  void *data, u8 icmp6_type)
 {
 	__ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
 				 ndisc_addr_option_pad(skb->dev->type));
+	ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
+}
+
+static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
+						   void *ha,
+						   const u8 *ops_data)
+{
+	ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
+	ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
 }
 
 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
@@ -191,24 +200,28 @@ static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 }
 
-static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
+static inline int ndisc_is_useropt(const struct net_device *dev,
+				   struct nd_opt_hdr *opt)
 {
 	return opt->nd_opt_type == ND_OPT_RDNSS ||
-		opt->nd_opt_type == ND_OPT_DNSSL;
+		opt->nd_opt_type == ND_OPT_DNSSL ||
+		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 }
 
-static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
+static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
+					     struct nd_opt_hdr *cur,
 					     struct nd_opt_hdr *end)
 {
 	if (!cur || !end || cur >= end)
 		return NULL;
 	do {
 		cur = ((void *)cur) + (cur->nd_opt_len << 3);
-	} while (cur < end && !ndisc_is_useropt(cur));
-	return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
+	} while (cur < end && !ndisc_is_useropt(dev, cur));
+	return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 }
 
-struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
+struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
+					  u8 *opt, int opt_len,
 					  struct ndisc_options *ndopts)
 {
 	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
@@ -223,6 +236,8 @@ struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 		l = nd_opt->nd_opt_len << 3;
 		if (opt_len < l || l == 0)
 			return NULL;
+		if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
+			goto next_opt;
 		switch (nd_opt->nd_opt_type) {
 		case ND_OPT_SOURCE_LL_ADDR:
 		case ND_OPT_TARGET_LL_ADDR:
@@ -249,7 +264,7 @@ struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 			break;
 #endif
 		default:
-			if (ndisc_is_useropt(nd_opt)) {
+			if (ndisc_is_useropt(dev, nd_opt)) {
 				ndopts->nd_useropts_end = nd_opt;
 				if (!ndopts->nd_useropts)
 					ndopts->nd_useropts = nd_opt;
@@ -266,6 +281,7 @@ struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 					  nd_opt->nd_opt_len);
 			}
 		}
+next_opt:
 		opt_len -= l;
 		nd_opt = ((void *)nd_opt) + l;
 	}
@@ -515,7 +531,8 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 	if (!dev->addr_len)
 		inc_opt = 0;
 	if (inc_opt)
-		optlen += ndisc_opt_addr_space(dev);
+		optlen += ndisc_opt_addr_space(dev,
+					       NDISC_NEIGHBOUR_ADVERTISEMENT);
 
 	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 	if (!skb)
@@ -534,8 +551,8 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 
 	if (inc_opt)
 		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
-				       dev->dev_addr);
-
+				       dev->dev_addr,
+				       NDISC_NEIGHBOUR_ADVERTISEMENT);
 
 	ndisc_send_skb(skb, daddr, src_addr);
 }
@@ -580,7 +597,8 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 	if (ipv6_addr_any(saddr))
 		inc_opt = false;
 	if (inc_opt)
-		optlen += ndisc_opt_addr_space(dev);
+		optlen += ndisc_opt_addr_space(dev,
+					       NDISC_NEIGHBOUR_SOLICITATION);
 
 	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 	if (!skb)
@@ -596,7 +614,8 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 
 	if (inc_opt)
 		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
-				       dev->dev_addr);
+				       dev->dev_addr,
+				       NDISC_NEIGHBOUR_SOLICITATION);
 
 	ndisc_send_skb(skb, daddr, saddr);
 }
@@ -632,7 +651,7 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 	}
 #endif
 	if (send_sllao)
-		optlen += ndisc_opt_addr_space(dev);
+		optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 
 	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 	if (!skb)
@@ -647,7 +666,8 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 
 	if (send_sllao)
 		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
-				       dev->dev_addr);
+				       dev->dev_addr,
+				       NDISC_ROUTER_SOLICITATION);
 
 	ndisc_send_skb(skb, daddr, saddr);
 }
@@ -708,6 +728,15 @@ static int pndisc_is_router(const void *pkey,
 	return ret;
 }
 
+void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
+		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
+		  struct ndisc_options *ndopts)
+{
+	neigh_update(neigh, lladdr, new, flags);
+	/* report ndisc ops about neighbour update */
+	ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
+}
+
 static void ndisc_recv_ns(struct sk_buff *skb)
 {
 	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
@@ -744,7 +773,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
 		return;
 	}
 
-	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
+	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 		ND_PRINTK(2, warn, "NS: invalid ND options\n");
 		return;
 	}
@@ -862,9 +891,10 @@ have_ifp:
 	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 			       !inc || lladdr || !dev->addr_len);
 	if (neigh)
-		neigh_update(neigh, lladdr, NUD_STALE,
+		ndisc_update(dev, neigh, lladdr, NUD_STALE,
 			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
-			     NEIGH_UPDATE_F_OVERRIDE);
+			     NEIGH_UPDATE_F_OVERRIDE,
+			     NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 	if (neigh || !dev->header_ops) {
 		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 			      true, (ifp != NULL && inc), inc);
@@ -917,7 +947,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
 	    idev->cnf.drop_unsolicited_na)
 		return;
 
-	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
+	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 		ND_PRINTK(2, warn, "NS: invalid ND option\n");
 		return;
 	}
@@ -973,12 +1003,13 @@ static void ndisc_recv_na(struct sk_buff *skb)
 			goto out;
 		}
 
-		neigh_update(neigh, lladdr,
+		ndisc_update(dev, neigh, lladdr,
 			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
-			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
+			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
+			     NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
 
 		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 			/*
@@ -1023,7 +1054,7 @@ static void ndisc_recv_rs(struct sk_buff *skb)
 		goto out;
 
 	/* Parse ND options */
-	if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
+	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
 		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
 		goto out;
 	}
@@ -1037,10 +1068,11 @@ static void ndisc_recv_rs(struct sk_buff *skb)
 
 	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
 	if (neigh) {
-		neigh_update(neigh, lladdr, NUD_STALE,
+		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
 			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 			     NEIGH_UPDATE_F_OVERRIDE|
-			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
+			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
+			     NDISC_ROUTER_SOLICITATION, &ndopts);
 		neigh_release(neigh);
 	}
 out:
@@ -1141,7 +1173,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 		return;
 	}
 
-	if (!ndisc_parse_options(opt, optlen, &ndopts)) {
+	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
 		ND_PRINTK(2, warn, "RA: invalid ND options\n");
 		return;
 	}
@@ -1335,11 +1367,12 @@ skip_linkparms:
 				goto out;
 			}
 		}
-		neigh_update(neigh, lladdr, NUD_STALE,
+		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
 			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 			     NEIGH_UPDATE_F_OVERRIDE|
 			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
-			     NEIGH_UPDATE_F_ISROUTER);
+			     NEIGH_UPDATE_F_ISROUTER,
+			     NDISC_ROUTER_ADVERTISEMENT, &ndopts);
 	}
 
 	if (!ipv6_accept_ra(in6_dev)) {
@@ -1427,7 +1460,8 @@ skip_routeinfo:
 		struct nd_opt_hdr *p;
 		for (p = ndopts.nd_useropts;
 		     p;
-		     p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
+		     p = ndisc_next_useropt(skb->dev, p,
+					    ndopts.nd_useropts_end)) {
 			ndisc_ra_useropt(skb, p);
 		}
 	}
@@ -1465,7 +1499,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
 		return;
 	}
 
-	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
+	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
 		return;
 
 	if (!ndopts.nd_opts_rh) {
@@ -1510,7 +1544,8 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 	struct dst_entry *dst;
 	struct flowi6 fl6;
 	int rd_len;
-	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
+	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
+	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
 	int oif = l3mdev_fib_oif(dev);
 	bool ret;
 
@@ -1569,7 +1604,9 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 			memcpy(ha_buf, neigh->ha, dev->addr_len);
 			read_unlock_bh(&neigh->lock);
 			ha = ha_buf;
-			optlen += ndisc_opt_addr_space(dev);
+			optlen += ndisc_redirect_opt_addr_space(dev, neigh,
+								ops_data_buf,
+								&ops_data);
 		} else
 			read_unlock_bh(&neigh->lock);
 
@@ -1600,7 +1637,7 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 	 */
 
 	if (ha)
-		ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
+		ndisc_fill_redirect_addr_option(buff, ha, ops_data);
 
 	/*
 	 *	build redirect option and copy skb over to the new packet.