libc/netdb: Separate IPv4 and IPv6 cache size limit

Some domains have a lot of IPv6 addresses. Because of that, it is
not possible to get the IPv4 address with getaddrinfo.

This change separate IPv4 and IPv6 cache size limit to enable to
get both IP addresses.

Author: SPRESENSE

boards/arm/tiva/lm3s6965-ek/configs/qemu-flat/defconfig

@@ -44,7 +44,6 @@ CONFIG_NET=y
 CONFIG_NETDB_DNSCLIENT=y
 CONFIG_NETDB_DNSCLIENT_NAMESIZE=64
 CONFIG_NETDB_DNSSERVER_NOADDR=y
-CONFIG_NETDB_MAX_IPADDR=2
 CONFIG_NETINIT_DHCPC=y
 CONFIG_NETINIT_NOMAC=y
 CONFIG_NETUTILS_NETCAT=y

boards/arm/tiva/lm3s6965-ek/configs/qemu-nxflat/defconfig

@@ -25,7 +25,6 @@ CONFIG_NET=y
 CONFIG_NETDB_DNSCLIENT=y
 CONFIG_NETDB_DNSCLIENT_NAMESIZE=64
 CONFIG_NETDB_DNSSERVER_NOADDR=y
-CONFIG_NETDB_MAX_IPADDR=2
 CONFIG_NETUTILS_NETCAT=y
 CONFIG_NETUTILS_TELNETD=y
 CONFIG_NETUTILS_TFTPC=y

boards/arm/tiva/lm3s6965-ek/configs/qemu-protected/defconfig

@@ -47,7 +47,6 @@ CONFIG_NET=y
 CONFIG_NETDB_DNSCLIENT=y
 CONFIG_NETDB_DNSCLIENT_NAMESIZE=64
 CONFIG_NETDB_DNSSERVER_NOADDR=y
-CONFIG_NETDB_MAX_IPADDR=2
 CONFIG_NETINIT_DHCPC=y
 CONFIG_NETINIT_NOMAC=y
 CONFIG_NETUTILS_NETCAT=y

boards/sim/sim/sim/configs/matter/defconfig

@@ -58,7 +58,6 @@ CONFIG_MATTER=y
 CONFIG_NET=y
 CONFIG_NETDB_DNSCLIENT=y
 CONFIG_NETDB_DNSSERVER_IPv4ADDR=0x771d1d1d
-CONFIG_NETDB_MAX_IPADDR=1
 CONFIG_NETDEV_HPWORK_THREAD=y
 CONFIG_NETINIT_IPADDR=0x0a000102
 CONFIG_NETLINK_ROUTE=y

boards/sim/sim/sim/configs/usbdev/defconfig

@@ -45,7 +45,6 @@ CONFIG_LIBUV=y
 CONFIG_NETDB_DNSCLIENT=y
 CONFIG_NETDB_DNSCLIENT_MAXRESPONSE=1024
 CONFIG_NETDB_DNSSERVER_IPv4ADDR=0xDF050505
-CONFIG_NETDB_MAX_IPADDR=1
 CONFIG_NETDEV_PHY_IOCTL=y
 CONFIG_NETDOWN_NOTIFIER=y
 CONFIG_NETINIT_DRIPADDR=0x0a000101

libs/libc/netdb/Kconfig

@@ -33,15 +33,30 @@ config NETDB_BUFSIZE
 	depends on LIBC_NETDB
 	default 256
 
-config NETDB_MAX_IPADDR
-	int "Max number of IP addresses per host"
+if NET_IPv4
+
+config NETDB_MAX_IPv4ADDR
+	int "Max number of IPv4 addresses per host"
 	depends on LIBC_NETDB
-	default 2 if NET_IPv4 && NET_IPv6
 	default 1
 	---help---
-		This setting determines the maximum number of IP addresses
+		This setting determines the maximum number of IPv4 addresses
 		stored to the name resolution cache for a given host.
 
+endif # NET_IPv4
+
+if NET_IPv6
+
+config NETDB_MAX_IPv6ADDR
+	int "Max number of IPv6 addresses per host"
+	depends on LIBC_NETDB
+	default 1
+	---help---
+		This setting determines the maximum number of IPv6 addresses
+		stored to the name resolution cache for a given host.
+
+endif # NET_IPv6
+
 menuconfig NETDB_HOSTFILE
 	bool "Network host file support"
 	default n

libs/libc/netdb/lib_dnscache.c

@@ -32,6 +32,7 @@
 #include <debug.h>
 
 #include "netdb/lib_dns.h"
+#include "netdb/lib_netdb.h"
 
 #if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
 

libs/libc/netdb/lib_dnsquery.c

@@ -669,7 +669,8 @@ static int dns_query_callback(FAR void *arg, FAR struct sockaddr *addr,
               /* Obtain the IPv6 response */
 
               ret = dns_recv_response(sd, &query->addr[next],
-                                      *query->naddr - next, &qdata->qinfo,
+                                      CONFIG_NETDB_MAX_IPv6ADDR,
+                                      &qdata->qinfo,
                                       &query->ttl, qdata->buffer);
               if (ret >= 0)
                 {
@@ -718,7 +719,8 @@ static int dns_query_callback(FAR void *arg, FAR struct sockaddr *addr,
                 }
 
               ret = dns_recv_response(sd, &query->addr[next],
-                                      *query->naddr - next, &qdata->qinfo,
+                                      CONFIG_NETDB_MAX_IPv4ADDR,
+                                      &qdata->qinfo,
                                       &query->ttl, qdata->buffer);
               if (ret >= 0)
                 {

libs/libc/netdb/lib_netdb.h

@@ -56,10 +56,17 @@
 #  define CONFIG_NETDB_BUFSIZE 128
 #endif
 
-#ifndef CONFIG_NETDB_MAX_IPADDR
-#  define CONFIG_NETDB_MAX_IPADDR 1
+#ifndef CONFIG_NETDB_MAX_IPv4ADDR
+#  define CONFIG_NETDB_MAX_IPv4ADDR 1
 #endif
 
+#ifndef CONFIG_NETDB_MAX_IPv6ADDR
+#  define CONFIG_NETDB_MAX_IPv6ADDR 1
+#endif
+
+#define CONFIG_NETDB_MAX_IPADDR (CONFIG_NETDB_MAX_IPv4ADDR + \
+                                 CONFIG_NETDB_MAX_IPv6ADDR)
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/