mdns: use constant size of AAAA answer in mdns packets instead of deriving from lwip struct size, since the struct could contain also zones

closes WIFI-771
This commit is contained in:
David Cermak 2019-09-24 12:12:58 +02:00
parent 8df2b046f4
commit e5e31c5d01
2 changed files with 12 additions and 7 deletions

View File

@ -22,6 +22,10 @@
void mdns_debug_packet(const uint8_t * data, size_t len);
#endif
// Internal size of IPv6 address is defined here as size of AAAA record in mdns packet
// since the ip6_addr_t is defined in lwip and depends on using IPv6 zones
#define _MDNS_SIZEOF_IP6_ADDR (MDNS_ANSWER_AAAA_SIZE)
static const char * MDNS_DEFAULT_DOMAIN = "local";
static const char * MDNS_SUB_STR = "_sub";
@ -734,11 +738,11 @@ static uint16_t _mdns_append_aaaa_record(uint8_t * packet, uint16_t * index, uin
uint16_t data_len_location = *index - 2;
if ((*index + 15) >= MDNS_MAX_PACKET_SIZE) {
if ((*index + MDNS_ANSWER_AAAA_SIZE) > MDNS_MAX_PACKET_SIZE) {
return 0;
}
part_length = sizeof(ip6_addr_t);
part_length = MDNS_ANSWER_AAAA_SIZE;
memcpy(packet + *index, ipv6, part_length);
*index += part_length;
_mdns_set_u16(packet, data_len_location, part_length);
@ -817,7 +821,7 @@ static bool _ipv6_address_is_zero(ip6_addr_t ip6)
{
uint8_t i;
uint8_t * data = (uint8_t *)ip6.addr;
for (i=0; i<16; i++) {
for (i=0; i<_MDNS_SIZEOF_IP6_ADDR; i++) {
if (data[i]) {
return false;
}
@ -2185,7 +2189,7 @@ static int _mdns_check_aaaa_collision(ip6_addr_t * ip, tcpip_adapter_if_t tcpip_
if (tcpip_adapter_get_ip6_linklocal(tcpip_if, &if_ip6)) {
return 1;//they win
}
int ret = memcmp((uint8_t*)&if_ip6.addr, (uint8_t*)ip->addr, sizeof(ip6_addr_t));
int ret = memcmp((uint8_t*)&if_ip6.addr, (uint8_t*)ip->addr, _MDNS_SIZEOF_IP6_ADDR);
if (ret > 0) {
return -1;//we win
} else if (ret < 0) {
@ -2197,7 +2201,7 @@ static int _mdns_check_aaaa_collision(ip6_addr_t * ip, tcpip_adapter_if_t tcpip_
if (tcpip_adapter_get_ip6_linklocal(other_if, &other_ip6)) {
return 1;//IPv6 not active! They win
}
if (memcmp((uint8_t*)&other_ip6.addr, (uint8_t*)ip->addr, sizeof(ip6_addr_t))) {
if (memcmp((uint8_t*)&other_ip6.addr, (uint8_t*)ip->addr, _MDNS_SIZEOF_IP6_ADDR)) {
return 1;//IPv6 not ours! They win
}
_mdns_dup_interface(tcpip_if);
@ -2898,7 +2902,7 @@ void mdns_parse_packet(mdns_rx_packet_t * packet)
} else if (type == MDNS_TYPE_AAAA) {//ipv6
ip_addr_t ip6;
ip6.type = IPADDR_TYPE_V6;
memcpy(ip6.u_addr.ip6.addr, data_ptr, 16);
memcpy(ip6.u_addr.ip6.addr, data_ptr, MDNS_ANSWER_AAAA_SIZE);
if (search_result) {
//check for more applicable searches (PTR & A/AAAA at the same time)
while (search_result) {
@ -4934,7 +4938,7 @@ void mdns_debug_packet(const uint8_t * data, size_t len)
_mdns_dbg_printf("\n");
} else if (type == MDNS_TYPE_AAAA) {
ip6_addr_t ip6;
memcpy(&ip6, data_ptr, sizeof(ip6_addr_t));
memcpy(&ip6, data_ptr, MDNS_ANSWER_AAAA_SIZE);
_mdns_dbg_printf(IPV6STR "\n", IPV62STR(ip6));
} else if (type == MDNS_TYPE_A) {
ip4_addr_t ip;

View File

@ -52,6 +52,7 @@
#define MDNS_ANSWER_AAAA 0x10
#define MDNS_ANSWER_NSEC 0x20
#define MDNS_ANSWER_SDPTR 0x80
#define MDNS_ANSWER_AAAA_SIZE 16
#define MDNS_SERVICE_PORT 5353 // UDP port that the server runs on
#define MDNS_SERVICE_STACK_DEPTH 4096 // Stack size for the service thread