int
resolv_init(struct ev_loop *loop, char **nameservers, int nameserver_num, int ipv6first)
{
if (ipv6first)
resolv_mode = MODE_IPV6_FIRST;
else
resolv_mode = MODE_IPV4_FIRST;
struct dns_ctx *ctx = &dns_defctx;
if (nameservers == NULL) {
/* Nameservers not specified, use system resolver config */
dns_init(ctx, 0);
} else {
dns_reset(ctx);
for (int i = 0; i < nameserver_num; i++) {
char *server = nameservers[i];
dns_add_serv(ctx, server);
}
}
int sockfd = dns_open(ctx);
if (sockfd < 0) {
FATAL("Failed to open DNS resolver socket");
}
if (nameserver_num == 1 && nameservers != NULL) {
if (strncmp("127.0.0.1", nameservers[0], 9) == 0
|| strncmp("::1", nameservers[0], 3) == 0) {
if (verbose) {
LOGI("bind UDP resolver to %s", nameservers[0]);
}
if (bind_to_address(sockfd, nameservers[0]) == -1)
ERROR("bind_to_address");
}
}
#ifdef __MINGW32__
setnonblocking(sockfd);
#else
int flags = fcntl(sockfd, F_GETFL, 0);
fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
#endif
ev_io_init(&resolv_io_watcher, resolv_sock_cb, sockfd, EV_READ);
resolv_io_watcher.data = ctx;
ev_io_start(loop, &resolv_io_watcher);
ev_timer_init(&resolv_timeout_watcher, resolv_timeout_cb, 0.0, 0.0);
resolv_timeout_watcher.data = ctx;
dns_set_tmcbck(ctx, dns_timer_setup_cb, loop);
return sockfd;
}
static inline int bind_socket(int sk, int index, int family)
{
char interface[IF_NAMESIZE];
int err;
if (if_indextoname(index, interface) == NULL)
return -1;
err = setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
interface, IF_NAMESIZE);
if (err < 0)
err = bind_to_address(sk, interface, family);
return err;
}
int bind_to_tcp_address(const char *ipaddr, const char *port, int backlog)
{
return bind_to_address(ipaddr, port, SOCK_STREAM, backlog);
}
int bind_to_udp_address(const char *ipaddr, const char *port)
{
return bind_to_address(ipaddr, port, SOCK_DGRAM, 0);
}