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 dns_ctx_handle_t *dns_ctx_alloc(const char *ns, int port) {
void *vh;
dns_ctx_handle_t *h = NULL;
pthread_mutex_lock(&dns_ctx_store_lock);
if(ns == NULL && default_ctx_handle != NULL) {
/* special case -- default context */
h = default_ctx_handle;
noit_atomic_inc32(&h->refcnt);
goto bail;
}
if(ns &&
noit_hash_retrieve(&dns_ctx_store, ns, strlen(ns), &vh)) {
h = (dns_ctx_handle_t *)vh;
noit_atomic_inc32(&h->refcnt);
}
else {
int failed = 0;
h = calloc(1, sizeof(*h));
h->ns = ns ? strdup(ns) : NULL;
h->ctx = dns_new(NULL);
if(dns_init(h->ctx, 0) != 0) failed++;
if(ns) {
if(dns_add_serv(h->ctx, NULL) < 0) failed++;
if(dns_add_serv(h->ctx, ns) < 0) failed++;
}
if(port && port != DNS_PORT) {
dns_set_opt(h->ctx, DNS_OPT_PORT, port);
}
if(dns_open(h->ctx) < 0) failed++;
if(failed) {
noitL(nlerr, "dns_open failed\n");
free(h->ns);
free(h);
h = NULL;
goto bail;
}
dns_set_tmcbck(h->ctx, eventer_dns_utm_fn, h);
h->e = eventer_alloc();
h->e->mask = EVENTER_READ | EVENTER_EXCEPTION;
h->e->closure = h;
h->e->callback = dns_eventer_callback;
h->e->fd = dns_sock(h->ctx);
eventer_add(h->e);
h->refcnt = 1;
if(!ns)
default_ctx_handle = h;
else
noit_hash_store(&dns_ctx_store, h->ns, strlen(h->ns), h);
}
bail:
pthread_mutex_unlock(&dns_ctx_store_lock);
return h;
}
int
resolv_init(struct ev_loop *loop) {
struct dns_ctx *ctx = &dns_defctx;
dns_init(ctx, 1);
int sockfd = dns_sock(ctx);
int flags = fcntl(sockfd, F_GETFL, 0);
fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
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;
}
void noit_check_resolver_init() {
eventer_t e;
if(dns_init(NULL, 0) < 0)
noitL(noit_error, "dns initialization failed.\n");
dns_ctx = dns_new(NULL);
if(dns_init(dns_ctx, 0) != 0 ||
dns_open(dns_ctx) < 0) {
noitL(noit_error, "dns initialization failed.\n");
}
eventer_name_callback("dns_cache_callback", dns_cache_callback);
dns_set_tmcbck(dns_ctx, dns_cache_utm_fn, dns_ctx);
e = eventer_alloc();
e->mask = EVENTER_READ | EVENTER_EXCEPTION;
e->closure = dns_ctx;
e->callback = dns_cache_callback;
e->fd = dns_sock(dns_ctx);
eventer_add(e);
noit_skiplist_init(&nc_dns_cache);
noit_skiplist_set_compare(&nc_dns_cache, name_lookup, name_lookup_k);
noit_skiplist_add_index(&nc_dns_cache, refresh_idx, refresh_idx_k);
noit_check_resolver_loop(NULL, 0, NULL, NULL);
register_console_dns_cache_commands();
}
void noit_check_resolver_init() {
int cnt;
mtev_conf_section_t *servers, *searchdomains;
eventer_t e;
if(dns_init(NULL, 0) < 0)
mtevL(noit_error, "dns initialization failed.\n");
dns_ctx = dns_new(NULL);
if(dns_init(dns_ctx, 0) != 0) {
mtevL(noit_error, "dns initialization failed.\n");
exit(-1);
}
/* Optional servers */
servers = mtev_conf_get_sections(NULL, "//resolver//server", &cnt);
if(cnt) {
int i;
char server[128];
dns_add_serv(dns_ctx, NULL); /* reset */
for(i=0;i<cnt;i++) {
if(mtev_conf_get_stringbuf(servers[i], "self::node()",
server, sizeof(server))) {
if(dns_add_serv(dns_ctx, server) < 0) {
mtevL(noit_error, "Failed adding DNS server: %s\n", server);
}
}
}
free(servers);
}
searchdomains = mtev_conf_get_sections(NULL, "//resolver//search", &cnt);
if(cnt) {
int i;
char search[128];
dns_add_srch(dns_ctx, NULL); /* reset */
for(i=0;i<cnt;i++) {
if(mtev_conf_get_stringbuf(searchdomains[i], "self::node()",
search, sizeof(search))) {
if(dns_add_srch(dns_ctx, search) < 0) {
mtevL(noit_error, "Failed adding DNS search path: %s\n", search);
}
else if(dns_search_flag) dns_search_flag = 0; /* enable search */
}
}
free(searchdomains);
}
if(mtev_conf_get_int(NULL, "//resolver/@ndots", &cnt))
dns_set_opt(dns_ctx, DNS_OPT_NDOTS, cnt);
if(mtev_conf_get_int(NULL, "//resolver/@ntries", &cnt))
dns_set_opt(dns_ctx, DNS_OPT_NTRIES, cnt);
if(mtev_conf_get_int(NULL, "//resolver/@timeout", &cnt))
dns_set_opt(dns_ctx, DNS_OPT_TIMEOUT, cnt);
if(dns_open(dns_ctx) < 0) {
mtevL(noit_error, "dns open failed.\n");
exit(-1);
}
eventer_name_callback("dns_cache_callback", dns_cache_callback);
dns_set_tmcbck(dns_ctx, dns_cache_utm_fn, dns_ctx);
e = eventer_alloc();
e->mask = EVENTER_READ | EVENTER_EXCEPTION;
e->closure = dns_ctx;
e->callback = dns_cache_callback;
e->fd = dns_sock(dns_ctx);
eventer_add(e);
mtev_skiplist_init(&nc_dns_cache);
mtev_skiplist_set_compare(&nc_dns_cache, name_lookup, name_lookup_k);
mtev_skiplist_add_index(&nc_dns_cache, refresh_idx, refresh_idx_k);
/* maybe load it from cache */
if(noit_resolver_cache_load_hook_exists()) {
struct timeval now;
char *key;
void *data;
int len;
gettimeofday(&now, NULL);
while(noit_resolver_cache_load_hook_invoke(&key, &data, &len) == MTEV_HOOK_CONTINUE) {
dns_cache_node *n;
n = calloc(1, sizeof(*n));
if(dns_cache_node_deserialize(n, data, len) >= 0) {
n->target = strdup(key);
/* if the TTL indicates that it will expire in less than 60 seconds
* (including stuff that should have already expired), then fudge
* the last_updated time to make it expire some random time within
* the next 60 seconds.
*/
if(n->last_needed > now.tv_sec || n->last_updated > now.tv_sec)
break; /* impossible */
n->last_needed = now.tv_sec;
if(n->last_updated + n->ttl < now.tv_sec + 60) {
int fudge = MIN(60, n->ttl) + 1;
n->last_updated = now.tv_sec - n->ttl + (lrand48() % fudge);
}
DCLOCK();
mtev_skiplist_insert(&nc_dns_cache, n);
DCUNLOCK();
n = NULL;
}
else {
mtevL(noit_error, "Failed to deserialize resolver cache record.\n");
}
if(n) dns_cache_node_free(n);
if(key) free(key);
if(data) free(data);
}
}
noit_check_resolver_loop(NULL, 0, NULL, NULL);
register_console_dns_cache_commands();
mtev_hash_init(&etc_hosts_cache);
noit_check_etc_hosts_cache_refresh(NULL, 0, NULL, NULL);
}
static dns_ctx_handle_t *dns_module_dns_ctx_alloc(noit_module_t *self, const char *ns, int port) {
void *vh;
char *hk = NULL;
dns_mod_config_t *conf = noit_module_get_userdata(self);
int randkey = random() % conf->contexts;
dns_ctx_handle_t *h = NULL;
if(ns && *ns == '\0') ns = NULL;
pthread_mutex_lock(&dns_ctx_store_lock);
if(ns == NULL && default_ctx_handle != NULL) {
/* special case -- default context */
h = default_ctx_handle;
dns_module_dns_ctx_acquire(h);
goto bail;
}
if (ns != NULL) {
int len = snprintf(NULL, 0, "%s:%d:%d", ns, port, randkey);
hk = (char *)malloc(len+1);
snprintf(hk, len+1, "%s:%d:%d", ns, port, randkey);
}
if(ns &&
noit_hash_retrieve(&dns_ctx_store, hk, strlen(hk), &vh)) {
h = (dns_ctx_handle_t *)vh;
dns_module_dns_ctx_acquire(h);
free(hk);
}
else {
int failed = 0;
h = calloc(1, sizeof(*h));
h->ns = ns ? strdup(ns) : NULL;
h->ctx = dns_new(NULL);
if(dns_init(h->ctx, 0) != 0) {
noitL(nlerr, "dns_init failed\n");
failed++;
}
dns_set_dbgfn(h->ctx, dns_debug_wrap);
if(ns) {
if(dns_add_serv(h->ctx, NULL) < 0) {
noitL(nlerr, "dns_add_serv(NULL) failed\n");
failed++;
}
if(dns_add_serv(h->ctx, ns) < 0) {
noitL(nlerr, "dns_add_serv(%s) failed\n", ns);
failed++;
}
}
if(port && port != DNS_PORT) {
dns_set_opt(h->ctx, DNS_OPT_PORT, port);
}
if(dns_open(h->ctx) < 0) {
noitL(nlerr, "dns_open failed\n");
failed++;
}
if(failed) {
free(h->ns);
dns_free(h->ctx);
free(h);
free(hk);
h = NULL;
goto bail;
}
h->hkey = hk;
dns_set_tmcbck(h->ctx, dns_module_eventer_dns_utm_fn, h);
h->e = eventer_alloc();
h->e->mask = EVENTER_READ | EVENTER_EXCEPTION;
h->e->closure = h;
h->e->callback = dns_module_eventer_callback;
h->e->fd = dns_sock(h->ctx);
eventer_add(h->e);
h->refcnt = 1;
if(!ns)
default_ctx_handle = h;
else
noit_hash_store(&dns_ctx_store, h->hkey, strlen(h->hkey), h);
}
bail:
pthread_mutex_unlock(&dns_ctx_store_lock);
return h;
}
