LwIP IPV6 DNS query failed

[jiangpen]

I have LwIP running on STM32+Cellular modem. The network is fine for IPV4. Now I am enabling IPV6.

I can see my IPV6 address assigned with my IPV4.

However, when I use lwip_getaddrinfo to have DNS query, but lwip_getaddrinfo return failed.

Any hints are really appreciate.

thanks

The code is like below:

const char * googleDNS1="2001:4860:4860::8888";
 
 const char * googleDNS2="2001:4860:4860::8844";
 
 ip6_addr_t addrV6_1, addrV6_2;
 
 int ret1=ip6addr_aton(googleDNS1,&addrV6_1 );
 
 int ret2=ip6addr_aton(googleDNS2,&addrV6_2 );
 
 printf("DNS convert returns %d, %d\r\n", ret1, ret2);
 
 ip_addr_t dns_addr1,dns_addr2 ;
 
 dns_addr1.type=IPADDR_TYPE_V6;
 
 memcpy(&(dns_addr1.u_addr.ip6), &addrV6_1, sizeof(addrV6_1));
 
 dns_setserver(0, &dns_addr1);//google IPV6 primary, 2001:4860:4860::8888
 
 dns_addr2.type=IPADDR_TYPE_V6;
 
 memcpy(&(dns_addr2.u_addr.ip6), &addrV6_2, sizeof(addrV6_2));
 
 dns_setserver(1, &dns_addr2);//google IPV6 primary, 2001:4860:4860::8888
 
 PRINT_PPPOSIF("  our6_ipaddr = %s", ip6addr_ntoa(netif_ip6_addr(pppif, 0)))
///////////////////////////////////////////////////////////////////////////////////////////////////////
memset( &hints, 0, sizeof( hints ) );
        hints.ai_family   = AF_INET6;     /* IPv4 or IPv6 records (don't care). */
        hints.ai_socktype = SOCK_STREAM;   /* Connection-oriented byte stream.   */
        hints.ai_protocol = IPPROTO_TCP;   /* TCP transport layer protocol only. */
        char ports[5];
        itoa(port, ports, 10);
 
        int aiErr=0;
        if ( ( aiErr = lwip_getaddrinfo( pHostName,
                ports,
                                       &hints,
                                       &res ) ) != 0 )
        {
            DBGLOG(DBG_SUBSYS_IOT_UTILITIES, LOG_ERR, "lwip_getaddrinfo %d", aiErr);
        }
 
 
        tcpSocket = com_socket(res->ai_family,
                res->ai_socktype,
                res->ai_protocol);
        if(tcpSocket<0)
        {
            DBGLOG(DBG_SUBSYS_IOT_UTILITIES, LOG_ERR, "com_socket return %d, retrying...\r\n",
                                                tcpSocket);
        }
 
        if (tcpSocket >= 0)
        {
            socketStatus = com_connect( tcpSocket, res->ai_addr, res->ai_addrlen);
 
        }

The log is like below:

netif_ip6_addr_set: netif address being changed
netif: IPv6 address 0 of interface pp set to FE80::A817:214E:1443:4B29/0x0hx
netif_ip6_addr_set_state: netif address state being changed
netif: IPv6 address 0 of interface pp set to FE80::A817:214E:1443:4B29/0x0hx
10.234    ppposif UTILS:
 
10.234    ppposif UTILS:   our_ipaddr  = 10.215.35.38
10.257    ppposif UTILS:   his_ipaddr  = 10.64.64.64
10.257    ppposif UTILS:   netmask     = 255.255.255.255
10.257    ppposif UTILS:   dns1        = 2001:4860:4860::8888
10.257    ppposif UTILS:   dns2        = 2001:4860:4860::8844
DNS convert returns 1, 1
10.277    ppposif UTILS:   our6_ipaddr = FE80::A817:214E:1443:4B29
 
dns_enqueue: "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com": use DNS entry 0
udp_bind(ipaddr = 0.0.0.0, port = 62509)
udp_bind: bound to 0.0.0.0, port 62509)
dns_enqueue: "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com": use DNS pcb 0
dns_send: dns_servers[0] "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com": request
pbuf_alloc(length=69)
pbuf_alloc(length=69) == 0x24012420
sending DNS request ID 36047 for name "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com" to server 0
udp_send
pbuf_add_header: old 0x2401247c new 0x24012474 (8)
udp_send: added header in given pbuf 0x24012420
udp_send: sending datagram of length 77
udp_send: UDP packet length 77
inet_chksum_pseudo(): checksumming pbuf 0x24012420 (has next 0) 
inet_chksum_pseudo(): pbuf chain lwip_chksum()=c2e5
udp_send: UDP checksum 0x3d1a
udp_send: ip_output_if (,,,,0x11,)
pbuf_add_header: old 0x24012474 new 0x2401244c (40)
ip6_output_if: pp0
netif->output_ip6()
lwip_netconn_do_gethostbyname returns,-5
dns_tmr: dns_check_entries
dns_send: dns_servers[0] "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com": request
pbuf_alloc(length=69)
pbuf_alloc(length=69) == 0x24012420
sending DNS request ID 36047 for name "a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com" to server 0
udp_send
pbuf_add_header: old 0x2401247c new 0x24012474 (8)
udp_send: added header in given pbuf 0x24012420
udp_send: sending datagram of length 77
udp_send: UDP packet length 77
inet_chksum_pseudo(): checksumming pbuf 0x24012420 (has next 0) 
inet_chksum_pseudo(): pbuf chain lwip_chksum()=c2e5
udp_send: UDP checksum 0x3d1a
udp_send: ip_output_if (,,,,0x11,)
pbuf_add_header: old 0x24012474 new 0x2401244c (40)
ip6_output_if: pp0