static int pico_dns_client_del_ns(struct pico_ip4 *ns_addr)
{
struct pico_dns_ns test = {{0}}, *found = NULL;
test.ns = *ns_addr;
found = pico_tree_findKey(&NSTable, &test);
if (!found)
return -1;
pico_tree_delete(&NSTable, found);
pico_free(found);
/* no NS left, add default NS */
if (pico_tree_empty(&NSTable))
pico_dns_client_init();
return 0;
}
int pico_dns_client_nameserver(struct pico_ip4 *ns, uint8_t flag)
{
struct pico_dns_ns test, *key = NULL;
if (!ns) {
pico_err = PICO_ERR_EINVAL;
return -1;
}
switch (flag)
{
case PICO_DNS_NS_ADD:
key = pico_zalloc(sizeof(struct pico_dns_ns));
if (!key) {
pico_err = PICO_ERR_ENOMEM;
return -1;
}
key->ns = *ns;
if(pico_tree_insert(&NSTable,key)){
dns_dbg("DNS WARNING: nameserver %08X already added\n",ns->addr);
pico_err = PICO_ERR_EINVAL;
pico_free(key);
return -1; /* Element key already exists */
}
dns_dbg("DNS: nameserver %08X added\n", ns->addr);
/* If default NS found, remove it */
pico_string_to_ipv4(PICO_DNS_NS_GOOGLE, &test.ns.addr);
if (ns->addr != test.ns.addr) {
key = pico_tree_findKey(&NSTable,&test);
if (key) {
if(pico_tree_delete(&NSTable,key)) {
dns_dbg("DNS: default nameserver %08X removed\n", test.ns.addr);
pico_free(key);
} else {
pico_err = PICO_ERR_EAGAIN;
return -1;
}
}
}
break;
case PICO_DNS_NS_DEL:
test.ns = *ns;
key = pico_tree_findKey(&NSTable,&test);
if (!key) {
dns_dbg("DNS WARNING: nameserver %08X not found\n", ns->addr);
pico_err = PICO_ERR_EINVAL;
return -1;
}
/* RB_REMOVE returns pointer to removed element, NULL to indicate error */
if(pico_tree_delete(&NSTable,key)) {
dns_dbg("DNS: nameserver %08X removed\n",key->ns.addr);
pico_free(key);
} else {
pico_err = PICO_ERR_EAGAIN;
return -1;
}
/* If no NS left, add default NS */
if(pico_tree_first(&NSTable) == NULL){
dns_dbg("DNS: add default nameserver\n");
return pico_dns_client_init();
}
break;
default:
pico_err = PICO_ERR_EINVAL;
return -1;
}
return 0;
}