static void dns_set_srch_internal(struct dns_ctx *ctx, char *srch) {
dns_add_srch(ctx, NULL);
for(srch = strtok(srch, space); srch; srch = strtok(NULL, space))
dns_add_srch(ctx, srch);
}
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;
}
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;
}
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);
}
