int ares_init_options(ares_channel *channelptr, struct ares_options *options,
int optmask)
{
ares_channel channel;
int i, status;
struct server_state *server;
struct timeval tv;
channel = malloc(sizeof(struct ares_channeldata));
if (!channel)
return ARES_ENOMEM;
/* Set everything to distinguished values so we know they haven't
* been set yet.
*/
channel->flags = -1;
channel->timeout = -1;
channel->tries = -1;
channel->ndots = -1;
channel->udp_port = -1;
channel->tcp_port = -1;
channel->nservers = -1;
channel->ndomains = -1;
channel->nsort = -1;
channel->lookups = NULL;
/* Initialize configuration by each of the four sources, from highest
* precedence to lowest.
*/
status = init_by_options(channel, options, optmask);
if (status == ARES_SUCCESS)
status = init_by_environment(channel);
if (status == ARES_SUCCESS)
status = init_by_resolv_conf(channel);
if (status == ARES_SUCCESS)
status = init_by_defaults(channel);
if (status != ARES_SUCCESS)
{
/* Something failed; clean up memory we may have allocated. */
if (channel->nservers != -1)
free(channel->servers);
if (channel->ndomains != -1)
{
for (i = 0; i < channel->ndomains; i++)
free(channel->domains[i]);
free(channel->domains);
}
if (channel->nsort != -1)
free(channel->sortlist);
free(channel->lookups);
free(channel);
return status;
}
/* Trim to one server if ARES_FLAG_PRIMARY is set. */
if ((channel->flags & ARES_FLAG_PRIMARY) && channel->nservers > 1)
channel->nservers = 1;
/* Initialize server states. */
for (i = 0; i < channel->nservers; i++)
{
server = &channel->servers[i];
server->udp_socket = -1;
server->tcp_socket = -1;
server->tcp_lenbuf_pos = 0;
server->tcp_buffer = NULL;
server->qhead = NULL;
server->qtail = NULL;
}
/* Choose a somewhat random query ID. The main point is to avoid
* collisions with stale queries. An attacker trying to spoof a DNS
* answer also has to guess the query ID, but it's only a 16-bit
* field, so there's not much to be done about that.
*/
gettimeofday(&tv, NULL);
channel->next_id = (tv.tv_sec ^ tv.tv_usec ^ getpid()) & 0xffff;
channel->queries = NULL;
*channelptr = channel;
return ARES_SUCCESS;
}
int ares_init_options(ares_channel *channelptr, struct ares_options *options,
int optmask)
{
ares_channel channel;
int i;
int status = ARES_SUCCESS;
struct timeval now;
#ifdef CURLDEBUG
const char *env = getenv("CARES_MEMDEBUG");
if (env)
curl_memdebug(env);
env = getenv("CARES_MEMLIMIT");
if (env) {
char *endptr;
long num = strtol(env, &endptr, 10);
if((endptr != env) && (endptr == env + strlen(env)) && (num > 0))
curl_memlimit(num);
}
#endif
if (ares_library_initialized() != ARES_SUCCESS)
return ARES_ENOTINITIALIZED;
channel = malloc(sizeof(struct ares_channeldata));
if (!channel) {
*channelptr = NULL;
return ARES_ENOMEM;
}
now = ares__tvnow();
/* Set everything to distinguished values so we know they haven't
* been set yet.
*/
channel->flags = -1;
channel->timeout = -1;
channel->tries = -1;
channel->ndots = -1;
channel->rotate = -1;
channel->udp_port = -1;
channel->tcp_port = -1;
channel->socket_send_buffer_size = -1;
channel->socket_receive_buffer_size = -1;
channel->nservers = -1;
channel->ndomains = -1;
channel->nsort = -1;
channel->tcp_connection_generation = 0;
channel->lookups = NULL;
channel->domains = NULL;
channel->sortlist = NULL;
channel->servers = NULL;
channel->sock_state_cb = NULL;
channel->sock_state_cb_data = NULL;
channel->sock_create_cb = NULL;
channel->sock_create_cb_data = NULL;
channel->last_server = 0;
channel->last_timeout_processed = (time_t)now.tv_sec;
memset(&channel->local_dev_name, 0, sizeof(channel->local_dev_name));
channel->local_ip4 = 0;
memset(&channel->local_ip6, 0, sizeof(channel->local_ip6));
/* Initialize our lists of queries */
ares__init_list_head(&(channel->all_queries));
for (i = 0; i < ARES_QID_TABLE_SIZE; i++)
{
ares__init_list_head(&(channel->queries_by_qid[i]));
}
for (i = 0; i < ARES_TIMEOUT_TABLE_SIZE; i++)
{
ares__init_list_head(&(channel->queries_by_timeout[i]));
}
/* Initialize configuration by each of the four sources, from highest
* precedence to lowest.
*/
if (status == ARES_SUCCESS) {
status = init_by_options(channel, options, optmask);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_options failed: %s\n",
ares_strerror(status)));
}
if (status == ARES_SUCCESS) {
status = init_by_environment(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_environment failed: %s\n",
ares_strerror(status)));
}
if (status == ARES_SUCCESS) {
status = init_by_resolv_conf(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_resolv_conf failed: %s\n",
ares_strerror(status)));
}
/*
* No matter what failed or succeeded, seed defaults to provide
* useful behavior for things that we missed.
*/
status = init_by_defaults(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_defaults failed: %s\n",
ares_strerror(status)));
/* Generate random key */
if (status == ARES_SUCCESS) {
status = init_id_key(&channel->id_key, ARES_ID_KEY_LEN);
if (status == ARES_SUCCESS)
channel->next_id = ares__generate_new_id(&channel->id_key);
else
DEBUGF(fprintf(stderr, "Error: init_id_key failed: %s\n",
ares_strerror(status)));
}
if (status != ARES_SUCCESS)
{
/* Something failed; clean up memory we may have allocated. */
if (channel->servers)
free(channel->servers);
if (channel->domains)
{
for (i = 0; i < channel->ndomains; i++)
free(channel->domains[i]);
free(channel->domains);
}
if (channel->sortlist)
free(channel->sortlist);
if(channel->lookups)
free(channel->lookups);
free(channel);
return status;
}
/* Trim to one server if ARES_FLAG_PRIMARY is set. */
if ((channel->flags & ARES_FLAG_PRIMARY) && channel->nservers > 1)
channel->nservers = 1;
ares__init_servers_state(channel);
*channelptr = channel;
return ARES_SUCCESS;
}