#include <stdlib.h>
#include <mach/mach.h>
#include <mach/mach_error.h>
#include "dnsinfo.h"
#include "dnsinfo_private.h"
#include "shared_dns_info.h"
static boolean_t
add_list(void **padding, uint32_t *n_padding, int32_t count, int32_t size, void **list)
{
int32_t need;
need = count * size;
if (need > *n_padding) {
return FALSE;
}
*list = (need == 0) ? NULL : *padding;
*padding += need;
*n_padding -= need;
return TRUE;
}
static _dns_config_buf_t *
copy_dns_info()
{
uint8_t *buf = NULL;
dnsDataOut_t dataRef = NULL;
mach_msg_type_number_t dataLen = 0;
mach_port_t server;
kern_return_t status;
server = _dns_configuration_server_port();
if (server == MACH_PORT_NULL) {
return NULL;
}
status = shared_dns_infoGet(server, &dataRef, &dataLen);
(void)mach_port_deallocate(mach_task_self(), server);
if (status != KERN_SUCCESS) {
mach_error("shared_dns_infoGet():", status);
return NULL;
}
if (dataRef != NULL) {
if (dataLen >= sizeof(_dns_config_buf_t)) {
_dns_config_buf_t *config = (_dns_config_buf_t *)dataRef;
uint32_t len;
uint32_t n_padding = ntohl(config->n_padding);
len = dataLen + n_padding;
buf = malloc(len);
bcopy((void *)dataRef, buf, dataLen);
bzero(&buf[dataLen], n_padding);
}
status = vm_deallocate(mach_task_self(), (vm_address_t)dataRef, dataLen);
if (status != KERN_SUCCESS) {
mach_error("vm_deallocate():", status);
free(buf);
return NULL;
}
}
return (_dns_config_buf_t *)buf;
}
static dns_resolver_t *
expand_resolver(_dns_resolver_buf_t *buf, uint32_t n_buf, void **padding, uint32_t *n_padding)
{
dns_attribute_t *attribute;
uint32_t n_attribute;
int32_t n_nameserver = 0;
int32_t n_search = 0;
int32_t n_sortaddr = 0;
dns_resolver_t *resolver = (dns_resolver_t *)&buf->resolver;
if (n_buf < sizeof(_dns_resolver_buf_t)) {
goto error;
}
resolver->domain = NULL;
resolver->n_nameserver = ntohl(resolver->n_nameserver);
if (!add_list(padding,
n_padding,
resolver->n_nameserver,
sizeof(struct sockaddr *),
(void **)&resolver->nameserver)) {
goto error;
}
resolver->port = ntohs(resolver->port);
resolver->n_search = ntohl(resolver->n_search);
if (!add_list(padding,
n_padding,
resolver->n_search,
sizeof(char *),
(void **)&resolver->search)) {
goto error;
}
resolver->n_sortaddr = ntohl(resolver->n_sortaddr);
if (!add_list(padding,
n_padding,
resolver->n_sortaddr,
sizeof(dns_sortaddr_t *),
(void **)&resolver->sortaddr)) {
goto error;
}
resolver->options = NULL;
resolver->timeout = ntohl(resolver->timeout);
resolver->search_order = ntohl(resolver->search_order);
n_attribute = n_buf - sizeof(_dns_resolver_buf_t);
attribute = (dns_attribute_t *)&buf->attribute[0];
if (n_attribute != ntohl(buf->n_attribute)) {
goto error;
}
while (n_attribute >= sizeof(dns_attribute_t)) {
int32_t attribute_length = ntohl(attribute->length);
switch (ntohl(attribute->type)) {
case RESOLVER_ATTRIBUTE_DOMAIN :
resolver->domain = (char *)&attribute->attribute[0];
break;
case RESOLVER_ATTRIBUTE_ADDRESS :
resolver->nameserver[n_nameserver++] = (struct sockaddr *)&attribute->attribute[0];
break;
case RESOLVER_ATTRIBUTE_SEARCH :
resolver->search[n_search++] = (char *)&attribute->attribute[0];
break;
case RESOLVER_ATTRIBUTE_SORTADDR :
resolver->sortaddr[n_sortaddr++] = (dns_sortaddr_t *)&attribute->attribute[0];
break;
case RESOLVER_ATTRIBUTE_OPTIONS :
resolver->options = (char *)&attribute->attribute[0];
break;
default :
break;
}
attribute = (dns_attribute_t *)((void *)attribute + attribute_length);
n_attribute -= attribute_length;
}
if ((n_nameserver != resolver->n_nameserver) ||
(n_search != resolver->n_search ) ||
(n_sortaddr != resolver->n_sortaddr )) {
goto error;
}
return resolver;
error :
return NULL;
}
static dns_config_t *
expand_config(_dns_config_buf_t *buf)
{
dns_attribute_t *attribute;
dns_config_t *config = (dns_config_t *)buf;
uint32_t n_attribute;
uint32_t n_padding;
int32_t n_resolver = 0;
void *padding;
padding = &buf->attribute[ntohl(buf->n_attribute)];
n_padding = ntohl(buf->n_padding);
config->n_resolver = ntohl(config->n_resolver);
if (!add_list(&padding,
&n_padding,
config->n_resolver,
sizeof(dns_resolver_t *),
(void **)&config->resolver)) {
goto error;
}
n_attribute = ntohl(buf->n_attribute);
attribute = (dns_attribute_t *)&buf->attribute[0];
while (n_attribute >= sizeof(dns_attribute_t)) {
int32_t attribute_length = ntohl(attribute->length);
switch (ntohl(attribute->type)) {
case CONFIG_ATTRIBUTE_RESOLVER : {
dns_resolver_t *resolver;
resolver = expand_resolver((_dns_resolver_buf_t *)&attribute->attribute[0],
attribute_length - sizeof(dns_attribute_t),
&padding,
&n_padding);
if (resolver == NULL) {
goto error;
}
config->resolver[n_resolver++] = resolver;
break;
}
default :
break;
}
attribute = (dns_attribute_t *)((void *)attribute + attribute_length);
n_attribute -= attribute_length;
}
if (n_resolver != config->n_resolver) {
goto error;
}
return config;
error :
return NULL;
}
__private_extern__
const char *
dns_configuration_notify_key()
{
return _dns_configuration_notify_key();
}
__private_extern__
dns_config_t *
dns_configuration_copy()
{
_dns_config_buf_t *buf;
dns_config_t *config;
buf = copy_dns_info();
if (buf == NULL) {
return NULL;
}
config = expand_config(buf);
if (config == NULL) {
free(buf);
return NULL;
}
return config;
}
__private_extern__
void
dns_configuration_free(dns_config_t *config)
{
if (config == NULL) {
return;
}
free((void *)config);
return;
}