[ipv6] Separate the concepts of prefix and address creation

Allow for IPv6 routing table entries to be created for an on-link
prefix where a local address has not yet been assigned to the network
device.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/ipv6.h

 	/** Network device */
 	struct net_device *netdev;
 
-	/** IPv6 address */
+	/** IPv6 address (or prefix if no address is defined) */
 	struct in6_addr address;
 	/** Prefix length */
 	unsigned int prefix_len;
 	/** IPv6 prefix mask (derived from prefix length) */
 	struct in6_addr prefix_mask;
-	/** Router address is present */
-	int has_router;
 	/** Router address */
 	struct in6_addr router;
+	/** Flags */
+	unsigned int flags;
+};
+
+/** IPv6 address/routing table entry flags */
+enum ipv6_miniroute_flags {
+	/** Routing table entry address is valid */
+	IPV6_HAS_ADDRESS = 0x0001,
+	/** Routing table entry router address is valid */
+	IPV6_HAS_ROUTER = 0x0002,
 };
 
 /**
 extern struct net_protocol ipv6_protocol __net_protocol;
 
 extern int ipv6_has_addr ( struct net_device *netdev, struct in6_addr *addr );
-extern int ipv6_slaac ( struct net_device *netdev, struct in6_addr *prefix,
-			unsigned int prefix_len, struct in6_addr *router );
+extern int ipv6_set_prefix ( struct net_device *netdev, struct in6_addr *prefix,
+			     unsigned int prefix_len, struct in6_addr *router );
+extern int ipv6_set_address ( struct net_device *netdev,
+			      struct in6_addr *address );
 
 #endif /* _IPXE_IPV6_H */

src/net/ipv6.c

 	return crc32_le ( 0, in, sizeof ( *in ) );
 }
 
+/**
+ * Dump IPv6 routing table entry
+ *
+ * @v miniroute		Routing table entry
+ */
+static inline __attribute__ (( always_inline )) void
+ipv6_dump_miniroute ( struct ipv6_miniroute *miniroute ) {
+	struct net_device *netdev = miniroute->netdev;
+
+	DBGC ( netdev, "IPv6 %s has %s %s/%d", netdev->name,
+	       ( ( miniroute->flags & IPV6_HAS_ADDRESS ) ?
+		 "address" : "prefix" ),
+	       inet6_ntoa ( &miniroute->address ), miniroute->prefix_len );
+	if ( miniroute->flags & IPV6_HAS_ROUTER )
+		DBGC ( netdev, " router %s", inet6_ntoa ( &miniroute->router ));
+	DBGC ( netdev, "\n" );
+}
+
 /**
  * Check if network device has a specific IPv6 address
  *
 
 	list_for_each_entry ( miniroute, &ipv6_miniroutes, list ) {
 		if ( ( miniroute->netdev == netdev ) &&
+		     ( miniroute->flags & IPV6_HAS_ADDRESS ) &&
 		     ( memcmp ( &miniroute->address, addr,
 				sizeof ( miniroute->address ) ) == 0 ) ) {
 			/* Found matching address */
 }
 
 /**
- * Add IPv6 minirouting table entry
+ * Find IPv6 routing table entry for a given address
  *
  * @v netdev		Network device
  * @v address		IPv6 address
+ * @ret miniroute	Routing table entry, or NULL if not found
+ */
+static struct ipv6_miniroute * ipv6_miniroute ( struct net_device *netdev,
+						struct in6_addr *address ) {
+	struct ipv6_miniroute *miniroute;
+
+	list_for_each_entry ( miniroute, &ipv6_miniroutes, list ) {
+		if ( ( miniroute->netdev == netdev ) &&
+		     ipv6_is_on_link ( miniroute, address ) ) {
+			return miniroute;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * Add IPv6 routing table entry
+ *
+ * @v netdev		Network device
+ * @v address		IPv6 address (or prefix)
  * @v prefix_len	Prefix length
- * @v router		Router address (or NULL)
+ * @v flags		Flags
  * @ret miniroute	Routing table entry, or NULL on failure
  */
-static struct ipv6_miniroute * __malloc
-add_ipv6_miniroute ( struct net_device *netdev, struct in6_addr *address,
-		     unsigned int prefix_len, struct in6_addr *router ) {
+static struct ipv6_miniroute * ipv6_add_miniroute ( struct net_device *netdev,
+						    struct in6_addr *address,
+						    unsigned int prefix_len,
+						    unsigned int flags ) {
 	struct ipv6_miniroute *miniroute;
 	uint8_t *prefix_mask;
 
-	DBGC ( netdev, "IPv6 add %s/%d ", inet6_ntoa ( address ), prefix_len );
-	if ( router )
-		DBGC ( netdev, "router %s ", inet6_ntoa ( router ) );
-	DBGC ( netdev, "via %s\n", netdev->name );
-
-	/* Allocate and populate miniroute structure */
+	/* Create routing table entry */
 	miniroute = zalloc ( sizeof ( *miniroute ) );
 	if ( ! miniroute )
 		return NULL;
-
-	/* Record routing information */
 	miniroute->netdev = netdev_get ( netdev );
 	memcpy ( &miniroute->address, address, sizeof ( miniroute->address ) );
 	miniroute->prefix_len = prefix_len;
 	}
 	if ( prefix_len )
 		*prefix_mask <<= ( 8 - prefix_len );
+	miniroute->flags = flags;
+	list_add ( &miniroute->list, &ipv6_miniroutes );
+	ipv6_dump_miniroute ( miniroute );
+
+	return miniroute;
+}
+
+/**
+ * Define IPv6 on-link prefix
+ *
+ * @v netdev		Network device
+ * @v prefix		IPv6 address prefix
+ * @v prefix_len	Prefix length
+ * @v router		Router address (or NULL)
+ * @ret rc		Return status code
+ */
+int ipv6_set_prefix ( struct net_device *netdev, struct in6_addr *prefix,
+		      unsigned int prefix_len, struct in6_addr *router ) {
+	struct ipv6_miniroute *miniroute;
+	int changed;
+
+	/* Find or create routing table entry */
+	miniroute = ipv6_miniroute ( netdev, prefix );
+	if ( ! miniroute )
+		miniroute = ipv6_add_miniroute ( netdev, prefix, prefix_len, 0);
+	if ( ! miniroute )
+		return -ENOMEM;
+
+	/* Record router and add to start or end of list as appropriate */
+	list_del ( &miniroute->list );
 	if ( router ) {
-		miniroute->has_router = 1;
+		changed = ( ( ! ( miniroute->flags & IPV6_HAS_ROUTER ) ) ||
+			    ( memcmp ( &miniroute->router, router,
+				       sizeof ( miniroute->router ) ) != 0 ) );
+		miniroute->flags |= IPV6_HAS_ROUTER;
 		memcpy ( &miniroute->router, router,
 			 sizeof ( miniroute->router ) );
-	}
-
-	/* Add to end of list if we have a gateway, otherwise to start
-	 * of list.
-	 */
-	if ( router ) {
 		list_add_tail ( &miniroute->list, &ipv6_miniroutes );
 	} else {
+		changed = ( miniroute->flags & IPV6_HAS_ROUTER );
+		miniroute->flags &= ~IPV6_HAS_ROUTER;
 		list_add ( &miniroute->list, &ipv6_miniroutes );
 	}
+	if ( changed )
+		ipv6_dump_miniroute ( miniroute );
 
-	return miniroute;
+	return 0;
 }
 
 /**
- * Delete IPv6 minirouting table entry
+ * Add IPv6 on-link address
  *
- * @v miniroute		Routing table entry
+ * @v netdev		Network device
+ * @v address		IPv6 address
+ * @ret rc		Return status code
+ *
+ * An on-link prefix for the address must already exist.
  */
-static void del_ipv6_miniroute ( struct ipv6_miniroute *miniroute ) {
-	struct net_device *netdev = miniroute->netdev;
+int ipv6_set_address ( struct net_device *netdev, struct in6_addr *address ) {
+	struct ipv6_miniroute *miniroute;
+	int changed;
+
+	/* Find routing table entry */
+	miniroute = ipv6_miniroute ( netdev, address );
+	if ( ! miniroute )
+		return -EADDRNOTAVAIL;
 
-	DBGC ( netdev, "IPv6 del %s/%d ", inet6_ntoa ( &miniroute->address ),
-	       miniroute->prefix_len );
-	if ( miniroute->has_router )
-		DBGC ( netdev, "router %s ", inet6_ntoa ( &miniroute->router ));
-	DBGC ( netdev, "via %s\n", netdev->name );
+	/* Record address */
+	changed = ( ( ! ( miniroute->flags & IPV6_HAS_ADDRESS ) ) ||
+		    ( memcmp ( &miniroute->address, address,
+			       sizeof ( miniroute->address ) ) != 0 ) );
+	memcpy ( &miniroute->address, address, sizeof ( miniroute->address ) );
+	miniroute->flags |= IPV6_HAS_ADDRESS;
+	if ( changed )
+		ipv6_dump_miniroute ( miniroute );
 
-	netdev_put ( miniroute->netdev );
-	list_del ( &miniroute->list );
-	free ( miniroute );
+	return 0;
 }
 
 /**
 		if ( ! netdev_is_open ( miniroute->netdev ) )
 			continue;
 
+		/* Skip routing table entries with no usable source address */
+		if ( ! ( miniroute->flags & IPV6_HAS_ADDRESS ) )
+			continue;
+
 		if ( IN6_IS_ADDR_LINKLOCAL ( *dest ) ||
 		     IN6_IS_ADDR_MULTICAST ( *dest ) ) {
 
 			 * address, and we have a default gateway,
 			 * then use this route.
 			 */
-			if ( miniroute->has_router ) {
+			if ( miniroute->flags & IPV6_HAS_ROUTER ) {
 				*dest = &miniroute->router;
 				return miniroute;
 			}
 	.format = format_ipv6_setting,
 };
 
-/**
- * Perform IPv6 stateless address autoconfiguration (SLAAC)
- *
- * @v netdev		Network device
- * @v prefix		Prefix
- * @v prefix_len	Prefix length
- * @v router		Router address (or NULL)
- * @ret rc		Return status code
- */
-int ipv6_slaac ( struct net_device *netdev, struct in6_addr *prefix,
-		 unsigned int prefix_len, struct in6_addr *router ) {
-	struct ipv6_miniroute *miniroute;
-	struct ipv6_miniroute *tmp;
-	struct in6_addr address;
-	int check_prefix_len;
-	int rc;
-
-	/* Construct local address */
-	memcpy ( &address, prefix, sizeof ( address ) );
-	check_prefix_len = ipv6_eui64 ( &address, netdev );
-	if ( check_prefix_len < 0 ) {
-		rc = check_prefix_len;
-		DBGC ( netdev, "IPv6 %s could not construct SLAAC address: "
-		       "%s\n", netdev->name, strerror ( rc ) );
-		return rc;
-	}
-	if ( check_prefix_len != ( int ) prefix_len ) {
-		DBGC ( netdev, "IPv6 %s incorrect SLAAC prefix length %d "
-		       "(expected %d)\n", netdev->name, prefix_len,
-		       check_prefix_len );
-		return -EINVAL;
-	}
-
-	/* Delete any existing SLAAC miniroutes for this prefix */
-	list_for_each_entry_safe ( miniroute, tmp, &ipv6_miniroutes, list ) {
-		if ( ipv6_is_on_link ( miniroute, &address ) )
-			del_ipv6_miniroute ( miniroute );
-	}
-
-	/* Add miniroute */
-	miniroute = add_ipv6_miniroute ( netdev, &address, prefix_len, router );
-	if ( ! miniroute )
-		return -ENOMEM;
-
-	return 0;
-}
-
 /**
  * Create IPv6 network device
  *
 	}
 
 	/* Create link-local address for this network device */
-	miniroute = add_ipv6_miniroute ( netdev, &address, prefix_len, NULL );
+	miniroute = ipv6_add_miniroute ( netdev, &address, prefix_len,
+					 IPV6_HAS_ADDRESS );
 	if ( ! miniroute )
 		return -ENOMEM;
 
 
 	/* Delete all miniroutes for this network device */
 	list_for_each_entry_safe ( miniroute, tmp, &ipv6_miniroutes, list ) {
-		if ( miniroute->netdev == netdev )
-			del_ipv6_miniroute ( miniroute );
+		if ( miniroute->netdev == netdev ) {
+			netdev_put ( miniroute->netdev );
+			list_del ( &miniroute->list );
+			free ( miniroute );
+		}
 	}
 }
 

src/net/ndp.c

 	/* Transmit packet */
 	if ( ( rc = tcpip_tx ( iobuf, &icmpv6_protocol, st_src, st_dest,
 			       netdev, &ndp->icmp.chksum ) ) != 0 ) {
-		DBGC ( netdev, "NDP could not transmit packet: %s\n",
-		       strerror ( rc ) );
+		DBGC ( netdev, "NDP %s could not transmit packet: %s\n",
+		       netdev->name, strerror ( rc ) );
 		return rc;
 	}
 
 	/* Sanity check */
 	if ( offsetof ( typeof ( *ll_addr_opt ),
 			ll_addr[ll_protocol->ll_addr_len] ) > len ) {
-		DBGC ( netdev, "NDP neighbour solicitation link-layer address "
-		       "option too short at %zd bytes\n", len );
+		DBGC ( netdev, "NDP %s neighbour solicitation link-layer "
+		       "address option too short at %zd bytes\n",
+		       netdev->name, len );
 		return -EINVAL;
 	}
 
 	if ( ( rc = neighbour_define ( netdev, &ipv6_protocol,
 				       &sin6_src->sin6_addr,
 				       ll_addr_opt->ll_addr ) ) != 0 ) {
-		DBGC ( netdev, "NDP could not define %s => %s: %s\n",
-		       inet6_ntoa ( &sin6_src->sin6_addr ),
+		DBGC ( netdev, "NDP %s could not define %s => %s: %s\n",
+		       netdev->name, inet6_ntoa ( &sin6_src->sin6_addr ),
 		       ll_protocol->ntoa ( ll_addr_opt->ll_addr ),
 		       strerror ( rc ) );
 		return rc;
 	/* Sanity check */
 	if ( offsetof ( typeof ( *ll_addr_opt ),
 			ll_addr[ll_protocol->ll_addr_len] ) > len ) {
-		DBGC ( netdev, "NDP neighbour advertisement link-layer address "
-		       "option too short at %zd bytes\n", len );
+		DBGC ( netdev, "NDP %s neighbour advertisement link-layer "
+		       "address option too short at %zd bytes\n",
+		       netdev->name, len );
 		return -EINVAL;
 	}
 
 	/* Update neighbour cache entry, if any */
 	if ( ( rc = neighbour_update ( netdev, &ipv6_protocol, &neigh->target,
 				       ll_addr_opt->ll_addr ) ) != 0 ) {
-		DBGC ( netdev, "NDP could not update %s => %s: %s\n",
-		       inet6_ntoa ( &neigh->target ),
+		DBGC ( netdev, "NDP %s could not update %s => %s: %s\n",
+		       netdev->name, inet6_ntoa ( &neigh->target ),
 		       ll_protocol->ntoa ( ll_addr_opt->ll_addr ),
 		       strerror ( rc ) );
 		return rc;
 	/* Sanity check */
 	if ( offsetof ( typeof ( *ll_addr_opt ),
 			ll_addr[ll_protocol->ll_addr_len] ) > len ) {
-		DBGC ( netdev, "NDP router advertisement link-layer address "
-		       "option too short at %zd bytes\n", len );
+		DBGC ( netdev, "NDP %s router advertisement link-layer address "
+		       "option too short at %zd bytes\n", netdev->name, len );
 		return -EINVAL;
 	}
 
 	if ( ( rc = neighbour_define ( netdev, &ipv6_protocol,
 				       &sin6_src->sin6_addr,
 				       ll_addr_opt->ll_addr ) ) != 0 ) {
-		DBGC ( netdev, "NDP could not define %s => %s: %s\n",
-		       inet6_ntoa ( &sin6_src->sin6_addr ),
+		DBGC ( netdev, "NDP %s could not define %s => %s: %s\n",
+		       netdev->name, inet6_ntoa ( &sin6_src->sin6_addr ),
 		       ll_protocol->ntoa ( ll_addr_opt->ll_addr ),
 		       strerror ( rc ) );
 		return rc;
 	struct ndp_router_advertisement_header *radv = &ndp->radv;
 	struct ndp_prefix_information_option *prefix_opt = &option->prefix;
 	struct in6_addr *router = &sin6_src->sin6_addr;
+	struct in6_addr address;
+	int prefix_len;
 	int rc;
 
 	/* Sanity check */
 	if ( sizeof ( *prefix_opt ) > len ) {
-		DBGC ( netdev, "NDP router advertisement prefix option too "
-		       "short at %zd bytes\n", len );
+		DBGC ( netdev, "NDP %s router advertisement prefix option too "
+		       "short at %zd bytes\n", netdev->name, len );
 		return -EINVAL;
 	}
-	DBGC ( netdev, "NDP found %sdefault router %s ",
-	       ( radv->lifetime ? "" : "non-" ),
+	DBGC ( netdev, "NDP %s found %sdefault router %s ",
+	       netdev->name, ( radv->lifetime ? "" : "non-" ),
 	       inet6_ntoa ( &sin6_src->sin6_addr ) );
 	DBGC ( netdev, "for %s-link %sautonomous prefix %s/%d\n",
 	       ( ( prefix_opt->flags & NDP_PREFIX_ON_LINK ) ? "on" : "off" ),
 	       inet6_ntoa ( &prefix_opt->prefix ),
 	       prefix_opt->prefix_len );
 
+	/* Ignore off-link prefixes */
+	if ( ! ( prefix_opt->flags & NDP_PREFIX_ON_LINK ) )
+		return 0;
+
+	/* Define prefix */
+	if ( ( rc = ipv6_set_prefix ( netdev, &prefix_opt->prefix,
+				      prefix_opt->prefix_len,
+				      ( radv->lifetime ?
+					router : NULL ) ) ) != 0 ) {
+		DBGC ( netdev, "NDP %s could not define prefix %s/%d: %s\n",
+		       netdev->name, inet6_ntoa ( &prefix_opt->prefix ),
+		       prefix_opt->prefix_len, strerror ( rc ) );
+		return rc;
+	}
+
 	/* Perform stateless address autoconfiguration, if applicable */
-	if ( ( prefix_opt->flags &
-	       ( NDP_PREFIX_ON_LINK | NDP_PREFIX_AUTONOMOUS ) ) ==
-	     ( NDP_PREFIX_ON_LINK | NDP_PREFIX_AUTONOMOUS ) ) {
-		if ( ( rc = ipv6_slaac ( netdev, &prefix_opt->prefix,
-					 prefix_opt->prefix_len,
-					 ( radv->lifetime ?
-					   router : NULL ) ) ) != 0 ) {
-			DBGC ( netdev, "NDP could not autoconfigure prefix %s/"
-			       "%d: %s\n", inet6_ntoa ( &prefix_opt->prefix ),
-			       prefix_opt->prefix_len, strerror ( rc ) );
+	if ( prefix_opt->flags & NDP_PREFIX_AUTONOMOUS ) {
+		memcpy ( &address, &prefix_opt->prefix, sizeof ( address ) );
+		prefix_len = ipv6_eui64 ( &address, netdev );
+		if ( prefix_len < 0 ) {
+			rc = prefix_len;
+			DBGC ( netdev, "NDP %s could not construct SLAAC "
+			       "address: %s\n", netdev->name, strerror ( rc ) );
+			return rc;
+		}
+		if ( prefix_len != prefix_opt->prefix_len ) {
+			DBGC ( netdev, "NDP %s incorrect SLAAC prefix length "
+			       "%d (expected %d)\n", netdev->name,
+			       prefix_opt->prefix_len, prefix_len );
+			return -EINVAL;
+		}
+		if ( ( rc = ipv6_set_address ( netdev, &address ) ) != 0 ) {
+			DBGC ( netdev, "NDP %s could not set address %s: %s\n",
+			       netdev->name, inet6_ntoa ( &address ),
+			       strerror ( rc ) );
 			return rc;
 		}
 	}
 
 	/* Sanity check */
 	if ( len < offset ) {
-		DBGC ( netdev, "NDP packet too short at %zd bytes (min %zd "
-		       "bytes)\n", len, offset );
+		DBGC ( netdev, "NDP %s packet too short at %zd bytes (min %zd "
+		       "bytes)\n", netdev->name, len, offset );
 		return -EINVAL;
 	}
 
 		     ( option->header.blocks == 0 ) ||
 		     ( remaining < ( option->header.blocks *
 				     NDP_OPTION_BLKSZ ) ) ) {
-			DBGC ( netdev, "NDP bad option length:\n" );
+			DBGC ( netdev, "NDP %s bad option length:\n",
+			       netdev->name );
 			DBGC_HDA ( netdev, 0, option, remaining );
 			return -EINVAL;
 		}
 		stateful = ( flags & NDP_ROUTER_MANAGED );
 		if ( ( rc = start_dhcpv6 ( &ipv6conf->dhcp, netdev,
 					   stateful ) ) != 0 ) {
-			DBGC ( netdev, "NDP could not start state%s DHCPv6: "
-			       "%s\n", ( stateful ? "ful" : "less" ),
-			       strerror ( rc ) );
+			DBGC ( netdev, "NDP %s could not start state%s DHCPv6: "
+			       "%s\n", netdev->name,
+			       ( stateful ? "ful" : "less" ), strerror ( rc ) );
 			ipv6conf_done ( ipv6conf, rc );
 			return rc;
 		}

src/usr/route_ipv6.c

 		printf ( "%s: %s/%d", netdev->name,
 			 inet6_ntoa ( &miniroute->address ),
 			 miniroute->prefix_len );
-		if ( miniroute->has_router )
+		if ( miniroute->flags & IPV6_HAS_ROUTER )
 			printf ( " gw %s", inet6_ntoa ( &miniroute->router ) );
+		if ( ! ( miniroute->flags & IPV6_HAS_ADDRESS ) )
+			printf ( " (no address)" );
 		if ( ! netdev_is_open ( miniroute->netdev ) )
 			printf ( " (inaccessible)" );
 		printf ( "\n" );