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, 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;
}
int main(int argc, char **argv) {
int c;
struct ipcheck ipc;
char *nameserver = NULL;
int zgiven = 0;
if (!(progname = strrchr(argv[0], '/'))) progname = argv[0];
else argv[0] = ++progname;
while((c = getopt(argc, argv, "hqtvms:S:cn:")) != EOF) switch(c) {
case 's': ++zgiven; addzone(optarg); break;
case 'S':
++zgiven;
if (addzonefile(optarg)) break;
fprintf(stderr, "%s: unable to read %s\n", progname, optarg);
return 1;
case 'c': ++zgiven; nzones = 0; break;
case 'q': --verbose; break;
case 'v': ++verbose; break;
case 't': do_txt = 1; break;
case 'n': nameserver = optarg; break;
case 'm': ++stopfirst; break;
case 'h':
printf("%s: %s.\n", progname, version);
printf("Usage is: %s [options] address..\n", progname);
printf(
"Where options are:\n"
" -h - print this help and exit\n"
" -s service - add the service (DNSBL zone) to the serice list\n"
" -S service-file - add the DNSBL zone(s) read from the given file\n"
" -c - clear service list\n"
" -v - increase verbosity level (more -vs => more verbose)\n"
" -q - decrease verbosity level (opposite of -v)\n"
" -t - obtain and print TXT records if any\n"
" -m - stop checking after first address match in any list\n"
" -n ipaddr - use the given nameserver instead of the default\n"
"(if no -s or -S option is given, use $RBLCHECK_ZONES, ~/.rblcheckrc\n"
"or /etc/rblcheckrc in that order)\n"
);
return 0;
default:
fprintf(stderr, "%s: use `%s -h' for help\n", progname, progname);
return 1;
}
if (!zgiven) {
char *s = getenv("RBLCHECK_ZONES");
if (s) {
char *k;
s = strdup(s);
k = strtok(s, " \t");
while(k) {
addzone(k);
k = strtok(NULL, " \t");
}
free(s);
}
else {
char *path;
char *home = getenv("HOME");
if (!home) home = ".";
path = malloc(strlen(home) + 1 + sizeof(".rblcheckrc"));
sprintf(path, "%s/.rblcheckrc", home);
if (!addzonefile(path))
addzonefile("/etc/rblcheckrc");
free(path);
}
}
if (!nzones) {
fprintf(stderr, "%s: no service (zone) list specified (-s or -S option)\n",
progname);
return 1;
}
argv += optind;
argc -= optind;
if (!argc)
return 0;
if (dns_init(0) < 0) {
fprintf(stderr, "%s: unable to initialize DNS library: %s\n",
progname, strerror(errno));
return 1;
}
if (nameserver) {
dns_add_serv(NULL, NULL);
if (dns_add_serv(NULL, nameserver) < 0)
fprintf(stderr, "%s: unable to use nameserver %s: %s\n",
progname, nameserver, strerror(errno));
}
if (dns_open(NULL) < 0) {
fprintf(stderr, "%s: unable to initialize DNS library: %s\n",
progname, strerror(errno));
return 1;
}
for (c = 0; c < argc; ++c) {
if (c && (verbose > 1 || (verbose == 1 && do_txt))) putchar('\n');
ipc.name = argv[c];
submit(&ipc);
waitdns(&ipc);
display_result(&ipc);
if (stopfirst > 1 && listed) break;
}
return listed ? 100 : failures ? 2 : 0;
}
static void dns_set_serv_internal(struct dns_ctx *ctx, char *serv) {
dns_add_serv(ctx, NULL);
for(serv = strtok(serv, space); serv; serv = strtok(NULL, space))
dns_add_serv(ctx, serv);
}
static int dns_init_resolvconf(struct dns_ctx *ctx) {
char *v;
char buf[2049]; /* this buffer is used to hold /etc/resolv.conf */
int has_srch = 0;
/* read resolv.conf... */
{ int fd = open("/etc/resolv.conf", O_RDONLY);
if (fd >= 0) {
int l = read(fd, buf, sizeof(buf) - 1);
close(fd);
buf[l < 0 ? 0 : l] = '\0';
}
else
buf[0] = '\0';
}
if (buf[0]) { /* ...and parse it */
char *line, *nextline;
line = buf;
do {
nextline = strchr(line, '\n');
if (nextline) *nextline++ = '\0';
v = line;
while(*v && !ISSPACE(*v)) ++v;
if (!*v) continue;
*v++ = '\0';
while(ISSPACE(*v)) ++v;
if (!*v) continue;
if (strcmp(line, "domain") == 0) {
dns_set_srch_internal(ctx, strtok(v, space));
has_srch = 1;
}
else if (strcmp(line, "search") == 0) {
dns_set_srch_internal(ctx, v);
has_srch = 1;
}
else if (strcmp(line, "nameserver") == 0)
dns_add_serv(ctx, strtok(v, space));
else if (strcmp(line, "options") == 0)
dns_set_opts(ctx, v);
} while((line = nextline) != NULL);
}
buf[sizeof(buf)-1] = '\0';
/* get list of nameservers from env. vars. */
if ((v = getenv("NSCACHEIP")) != NULL ||
(v = getenv("NAMESERVERS")) != NULL) {
strncpy(buf, v, sizeof(buf) - 1);
dns_set_serv_internal(ctx, buf);
}
/* if $LOCALDOMAIN is set, use it for search list */
if ((v = getenv("LOCALDOMAIN")) != NULL) {
strncpy(buf, v, sizeof(buf) - 1);
dns_set_srch_internal(ctx, buf);
has_srch = 1;
}
if ((v = getenv("RES_OPTIONS")) != NULL)
dns_set_opts(ctx, v);
/* if still no search list, use local domain name */
if (has_srch &&
gethostname(buf, sizeof(buf) - 1) == 0 &&
(v = strchr(buf, '.')) != NULL &&
*++v != '\0')
dns_add_srch(ctx, v);
return 0;
}
static int dns_init_resolvconf(struct dns_ctx *ctx) {
char *v;
char buf[4097]; /* this buffer is used to hold /etc/resolv.conf */
int has_srch = 0;
/* read resolv.conf... */
{ int fd = open("/etc/resolv.conf", O_RDONLY);
if (fd >= 0) {
int l = read(fd, buf, sizeof(buf) - 1);
close(fd);
buf[l < 0 ? 0 : l] = '\0';
}
else
buf[0] = '\0';
}
if (buf[0]) { /* ...and parse it */
char *line, *nextline;
line = buf;
do {
nextline = strchr(line, '\n');
if (nextline) *nextline++ = '\0';
v = line;
while(*v && !ISSPACE(*v)) ++v;
if (!*v) continue;
*v++ = '\0';
while(ISSPACE(*v)) ++v;
if (!*v) continue;
if (strcmp(line, "domain") == 0) {
dns_set_srch_internal(ctx, strtok(v, space));
has_srch = 1;
}
else if (strcmp(line, "search") == 0) {
dns_set_srch_internal(ctx, v);
has_srch = 1;
}
else if (strcmp(line, "nameserver") == 0)
dns_add_serv(ctx, strtok(v, space));
else if (strcmp(line, "options") == 0)
dns_set_opts(ctx, v);
} while((line = nextline) != NULL);
}
buf[sizeof(buf)-1] = '\0';
#if TARGET_OS_IPHONE
// SOLUTION FOUND:
// http://iphone.galloway.me.uk/2009/11/iphone-dns-servers/
// ORIGINAL CODE EXAMPLE:
//
// #if TARGET_OS_IPHONE
// #include <resolv.h>
// #endif
//
// ...
//
// #if TARGET_OS_IPHONE
// // XXX: On the iPhone we need to get the DNS servers using resolv.h magic
// if ((_res.options & RES_INIT) == 0) res_init();
// channel->nservers = _res.nscount;
// channel->servers = malloc(channel->nservers * sizeof(struct server_state));
// memset(channel->servers, '\0', channel->nservers * sizeof(struct server_state));
//
// int i;
// for (i = 0; i < channel->nservers; i++)
// {
// memcpy(&channel->servers[i].addr, &_res.nsaddr_list[i].sin_addr, sizeof(struct in_addr));
// }
// #endif
if ((_res.options & RES_INIT) == 0) res_init();
int i;
for (i = 0; i < _res.nscount; i++)
{
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
address.sin_family = AF_INET;
address.sin_addr = _res.nsaddr_list[i].sin_addr; // loopback is a special case since it could be stored as ::1 in IPv6
dns_add_serv_s(ctx, (struct sockaddr *)&address);
}
#endif //TARGET_OS_IPHONE
/* get list of nameservers from env. vars. */
if ((v = getenv("NSCACHEIP")) != NULL ||
(v = getenv("NAMESERVERS")) != NULL) {
strncpy(buf, v, sizeof(buf) - 1);
dns_set_serv_internal(ctx, buf);
}
/* if $LOCALDOMAIN is set, use it for search list */
if ((v = getenv("LOCALDOMAIN")) != NULL) {
strncpy(buf, v, sizeof(buf) - 1);
dns_set_srch_internal(ctx, buf);
has_srch = 1;
}
if ((v = getenv("RES_OPTIONS")) != NULL)
dns_set_opts(ctx, v);
/* if still no search list, use local domain name */
if (has_srch &&
gethostname(buf, sizeof(buf) - 1) == 0 &&
(v = strchr(buf, '.')) != NULL &&
*++v != '\0')
dns_add_srch(ctx, v);
return 0;
}
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;
}
