ipv6: Export ndisc option parsing from ndisc.c

This is going to be used internally by the rt6 redirect code.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 50 insertions, 0 deletions

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index c02b6ad..96a3b5c 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -47,6 +47,8 @@ enum {
 #include <linux/icmpv6.h>
 #include <linux/in6.h>
 #include <linux/types.h>
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
 
 #include <net/neighbour.h>
 
@@ -80,6 +82,54 @@ struct nd_opt_hdr {
 	__u8		nd_opt_len;
 } __packed;
 
+/* ND options */
+struct ndisc_options {
+	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
+#ifdef CONFIG_IPV6_ROUTE_INFO
+	struct nd_opt_hdr *nd_opts_ri;
+	struct nd_opt_hdr *nd_opts_ri_end;
+#endif
+	struct nd_opt_hdr *nd_useropts;
+	struct nd_opt_hdr *nd_useropts_end;
+};
+
+#define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
+#define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
+#define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
+#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 NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
+
+extern struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
+						 struct ndisc_options *ndopts);
+
+/*
+ * Return the padding between the option length and the start of the
+ * link addr.  Currently only IP-over-InfiniBand needs this, although
+ * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
+ * also need a pad of 2.
+ */
+static int ndisc_addr_option_pad(unsigned short type)
+{
+	switch (type) {
+	case ARPHRD_INFINIBAND: return 2;
+	default:                return 0;
+	}
+}
+
+static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
+				      struct net_device *dev)
+{
+	u8 *lladdr = (u8 *)(p + 1);
+	int lladdrlen = p->nd_opt_len << 3;
+	int prepad = ndisc_addr_option_pad(dev->type);
+	if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
+		return NULL;
+	return lladdr + prepad;
+}
+
 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 {
 	const u32 *p32 = pkey;