add support for DNS Search List (rfc6106)

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

2 files changed, 89 insertions, 0 deletions

diff --git a/libndp/libndp.c b/libndp/libndp.c
index 44da3e7..88e0e36 100644
--- a/libndp/libndp.c
+++ b/libndp/libndp.c
@@ -1013,6 +1013,10 @@ static struct ndp_msg_opt_type_info ndp_msg_opt_type_info_list[] =
 		.raw_type = __ND_OPT_RDNSS,
 		.raw_struct_size = sizeof(struct __nd_opt_rdnss),
 	},
+	[NDP_MSG_OPT_DNSSL] = {
+		.raw_type = __ND_OPT_DNSSL,
+		.raw_struct_size = sizeof(struct __nd_opt_dnssl),
+	},
 };
 
 #define NDP_MSG_OPT_TYPE_LIST_SIZE ARRAY_SIZE(ndp_msg_opt_type_info_list)
@@ -1415,6 +1419,81 @@ struct in6_addr *ndp_msg_opt_rdnss_addr(struct ndp_msg *msg, int offset,
 	return &addr;
 }
 
+/**
+ * ndp_msg_opt_dnssl_lifetime:
+ * @msg: message structure
+ * @offset: in-message offset
+ *
+ * Get DNS Search List lifetime.
+ * User should use this function only inside ndp_msg_opt_for_each_offset()
+ * macro loop.
+ *
+ * Returns: route lifetime in seconds, (uint32_t) -1 means infinity.
+ **/
+NDP_EXPORT
+uint32_t ndp_msg_opt_dnssl_lifetime(struct ndp_msg *msg, int offset)
+{
+	struct __nd_opt_dnssl *dnssl =
+			ndp_msg_payload_opts_offset(msg, offset);
+
+	return ntohl(dnssl->nd_opt_dnssl_lifetime);
+}
+
+/**
+ * ndp_msg_opt_dnssl_domain:
+ * @msg: message structure
+ * @offset: in-message offset
+ * @domain_index: domain index
+ *
+ * Get DNS Search List domain.
+ * User should use this function only inside ndp_msg_opt_for_each_offset()
+ * macro loop.
+ *
+ * Returns: address.
+ **/
+NDP_EXPORT
+char *ndp_msg_opt_dnssl_domain(struct ndp_msg *msg, int offset,
+			       int domain_index)
+{
+	int i;
+	static char buf[256];
+	struct __nd_opt_dnssl *dnssl =
+			ndp_msg_payload_opts_offset(msg, offset);
+	size_t len = dnssl->nd_opt_dnssl_len << 3; /* convert to bytes */
+	char *ptr;
+
+	len -= in_struct_offset(struct __nd_opt_dnssl, nd_opt_dnssl_domains);
+	ptr = dnssl->nd_opt_dnssl_domains;
+
+	i = 0;
+	while (len > 0) {
+		*buf = '\0';
+		while (len > 0) {
+			uint8_t dom_len = *ptr;
+
+			ptr++;
+			len--;
+			if (!dom_len)
+				break;
+
+			if (dom_len > len)
+				return NULL;
+
+			if (strlen(buf))
+				sprintf(buf, "%s.", buf);
+			buf[strlen(buf) + dom_len] = '\0';
+			memcpy(buf + strlen(buf), ptr, dom_len);
+			ptr += dom_len;
+			len -= dom_len;
+		}
+		if (!strlen(buf))
+			break;
+		if (i++ == domain_index)
+			return buf;
+	}
+	return NULL;
+}
+
 static int ndp_call_handlers(struct ndp *ndp, struct ndp_msg *msg);
 
 static int ndp_sock_recv(struct ndp *ndp)
diff --git a/libndp/ndp_private.h b/libndp/ndp_private.h
index 7424e8c..49ecad0 100644
--- a/libndp/ndp_private.h
+++ b/libndp/ndp_private.h
@@ -84,6 +84,7 @@ ndp_log_null(struct ndp *ndp, const char *format, ...) {}
 
 #define __ND_OPT_ROUTE_INFO 24 /* rfc4191 */
 #define __ND_OPT_RDNSS 25 /* rfc6106 */
+#define __ND_OPT_DNSSL 31 /* rfc6106 */
 
 struct __nd_opt_route_info { /* route information */
 	uint8_t		nd_opt_ri_type;
@@ -102,4 +103,13 @@ struct __nd_opt_rdnss { /* Recursive DNS Server */
 	char		nd_opt_rdnss_addresses[0];
 };
 
+struct __nd_opt_dnssl { /* DNS Search List */
+	uint8_t		nd_opt_dnssl_type;
+	uint8_t		nd_opt_dnssl_len;
+	uint16_t	nd_opt_dnssl_reserved;
+	uint32_t	nd_opt_dnssl_lifetime;
+	char		nd_opt_dnssl_domains[0];
+};
+
+
 #endif /* _NDP_PRIVATE_H_ */