static void
nss_ubdns_load_resolvconf(void) {
struct stat sb;
if (stat(NSS_UBDNS_RESOLVCONF, &sb) == 0) {
ub_ctx_resolvconf(ctx, NSS_UBDNS_RESOLVCONF);
} else {
ub_ctx_set_fwd(ctx, "127.0.0.1");
}
}
DNSResolver::DNSResolver() : m_data(new DNSResolverData())
{
int use_dns_public = 0;
const char* dns_public_addr = "8.8.4.4";
if (auto res = getenv("DNS_PUBLIC"))
{
std::string dns_public(res);
// TODO: could allow parsing of IP and protocol: e.g. DNS_PUBLIC=tcp:8.8.8.8
if (dns_public == "tcp")
{
LOG_PRINT_L0("Using public DNS server: " << dns_public_addr << " (TCP)");
use_dns_public = 1;
}
}
// init libunbound context
m_data->m_ub_context = ub_ctx_create();
if (use_dns_public)
{
ub_ctx_set_fwd(m_data->m_ub_context, dns_public_addr);
ub_ctx_set_option(m_data->m_ub_context, "do-udp:", "no");
ub_ctx_set_option(m_data->m_ub_context, "do-tcp:", "yes");
}
else {
// look for "/etc/resolv.conf" and "/etc/hosts" or platform equivalent
ub_ctx_resolvconf(m_data->m_ub_context, NULL);
ub_ctx_hosts(m_data->m_ub_context, NULL);
}
#ifdef DEVELOPER_LIBUNBOUND_OLD
#pragma message "Using the work around for old libunbound"
{ // work around for bug https://www.nlnetlabs.nl/bugs-script/show_bug.cgi?id=515 needed for it to compile on e.g. Debian 7
char * ds_copy = NULL; // this will be the writable copy of string that bugged version of libunbound requires
try {
char * ds_copy = strdup( ::get_builtin_ds() );
ub_ctx_add_ta(m_data->m_ub_context, ds_copy);
} catch(...) { // probably not needed but to work correctly in every case...
if (ds_copy) { free(ds_copy); ds_copy=NULL; } // for the strdup
throw ;
}
if (ds_copy) { free(ds_copy); ds_copy=NULL; } // for the strdup
}
#else
// normal version for fixed libunbound
ub_ctx_add_ta(m_data->m_ub_context, ::get_builtin_ds() );
#endif
}
DNSResolver::DNSResolver() : m_data(new DNSResolverData())
{
int use_dns_public = 0;
std::vector<std::string> dns_public_addr;
if (auto res = getenv("DNS_PUBLIC"))
{
dns_public_addr = tools::dns_utils::parse_dns_public(res);
if (!dns_public_addr.empty())
{
MGINFO("Using public DNS server(s): " << boost::join(dns_public_addr, ", ") << " (TCP)");
use_dns_public = 1;
}
else
{
MERROR("Failed to parse DNS_PUBLIC");
}
}
// init libunbound context
m_data->m_ub_context = ub_ctx_create();
if (use_dns_public)
{
for (const auto &ip: dns_public_addr)
ub_ctx_set_fwd(m_data->m_ub_context, string_copy(ip.c_str()));
ub_ctx_set_option(m_data->m_ub_context, string_copy("do-udp:"), string_copy("no"));
ub_ctx_set_option(m_data->m_ub_context, string_copy("do-tcp:"), string_copy("yes"));
}
else {
// look for "/etc/resolv.conf" and "/etc/hosts" or platform equivalent
ub_ctx_resolvconf(m_data->m_ub_context, NULL);
ub_ctx_hosts(m_data->m_ub_context, NULL);
}
const char * const *ds = ::get_builtin_ds();
while (*ds)
{
MINFO("adding trust anchor: " << *ds);
ub_ctx_add_ta(m_data->m_ub_context, string_copy(*ds++));
}
}
int
ub_ctx_resolvconf(struct ub_ctx* ctx, char* fname)
{
FILE* in;
int numserv = 0;
char buf[1024];
char* parse, *addr;
int r;
if(fname == NULL) {
#if !defined(UB_ON_WINDOWS) || !defined(HAVE_WINDOWS_H)
fname = "/etc/resolv.conf";
#else
FIXED_INFO *info;
ULONG buflen = sizeof(*info);
IP_ADDR_STRING *ptr;
info = (FIXED_INFO *) malloc(sizeof (FIXED_INFO));
if (info == NULL)
return UB_READFILE;
if (GetNetworkParams(info, &buflen) == ERROR_BUFFER_OVERFLOW) {
free(info);
info = (FIXED_INFO *) malloc(buflen);
if (info == NULL)
return UB_READFILE;
}
if (GetNetworkParams(info, &buflen) == NO_ERROR) {
int retval=0;
ptr = &(info->DnsServerList);
while (ptr) {
numserv++;
if((retval=ub_ctx_set_fwd(ctx,
ptr->IpAddress.String)!=0)) {
free(info);
return retval;
}
ptr = ptr->Next;
}
free(info);
if (numserv==0)
return UB_READFILE;
return UB_NOERROR;
}
free(info);
return UB_READFILE;
#endif /* WINDOWS */
}
in = fopen(fname, "r");
if(!in) {
/* error in errno! perror(fname) */
return UB_READFILE;
}
while(fgets(buf, (int)sizeof(buf), in)) {
buf[sizeof(buf)-1] = 0;
parse=buf;
while(*parse == ' ' || *parse == '\t')
parse++;
if(strncmp(parse, "nameserver", 10) == 0) {
numserv++;
parse += 10; /* skip 'nameserver' */
/* skip whitespace */
while(*parse == ' ' || *parse == '\t')
parse++;
addr = parse;
/* skip [0-9a-fA-F.:]*, i.e. IP4 and IP6 address */
while(isxdigit(*parse) || *parse=='.' || *parse==':')
parse++;
/* terminate after the address, remove newline */
*parse = 0;
if((r = ub_ctx_set_fwd(ctx, addr)) != UB_NOERROR) {
fclose(in);
return r;
}
}
}
fclose(in);
if(numserv == 0) {
/* from resolv.conf(5) if none given, use localhost */
return ub_ctx_set_fwd(ctx, "127.0.0.1");
}
return UB_NOERROR;
}
/** main program for asynclook */
int main(int argc, char** argv)
{
int c;
struct ub_ctx* ctx;
struct lookinfo* lookups;
int i, r, cancel=0, blocking=0, ext=0;
/* init log now because solaris thr_key_create() is not threadsafe */
log_init(0,0,0);
/* lock debug start (if any) */
checklock_start();
/* create context */
ctx = ub_ctx_create();
if(!ctx) {
printf("could not create context, %s\n", strerror(errno));
return 1;
}
/* command line options */
if(argc == 1) {
usage(argv);
}
while( (c=getopt(argc, argv, "bcdf:hH:r:tx")) != -1) {
switch(c) {
case 'd':
r = ub_ctx_debuglevel(ctx, 3);
checkerr("ub_ctx_debuglevel", r);
break;
case 't':
r = ub_ctx_async(ctx, 1);
checkerr("ub_ctx_async", r);
break;
case 'c':
cancel = 1;
break;
case 'b':
blocking = 1;
break;
case 'r':
r = ub_ctx_resolvconf(ctx, optarg);
if(r != 0) {
printf("ub_ctx_resolvconf "
"error: %s : %s\n",
ub_strerror(r),
strerror(errno));
return 1;
}
break;
case 'H':
r = ub_ctx_hosts(ctx, optarg);
if(r != 0) {
printf("ub_ctx_hosts "
"error: %s : %s\n",
ub_strerror(r),
strerror(errno));
return 1;
}
break;
case 'f':
r = ub_ctx_set_fwd(ctx, optarg);
checkerr("ub_ctx_set_fwd", r);
break;
case 'x':
ext = 1;
break;
case 'h':
case '?':
default:
usage(argv);
}
}
argc -= optind;
argv += optind;
if(ext)
return ext_test(ctx, argc, argv);
/* allocate array for results. */
lookups = (struct lookinfo*)calloc((size_t)argc,
sizeof(struct lookinfo));
if(!lookups) {
printf("out of memory\n");
return 1;
}
/* perform asynchronous calls */
num_wait = argc;
for(i=0; i<argc; i++) {
lookups[i].name = argv[i];
if(blocking) {
fprintf(stderr, "lookup %s\n", argv[i]);
r = ub_resolve(ctx, argv[i], LDNS_RR_TYPE_A,
LDNS_RR_CLASS_IN, &lookups[i].result);
checkerr("ub_resolve", r);
} else {
fprintf(stderr, "start async lookup %s\n", argv[i]);
r = ub_resolve_async(ctx, argv[i], LDNS_RR_TYPE_A,
LDNS_RR_CLASS_IN, &lookups[i], &lookup_is_done,
&lookups[i].async_id);
checkerr("ub_resolve_async", r);
}
}
if(blocking)
num_wait = 0;
else if(cancel) {
for(i=0; i<argc; i++) {
fprintf(stderr, "cancel %s\n", argv[i]);
r = ub_cancel(ctx, lookups[i].async_id);
if(r != UB_NOID)
checkerr("ub_cancel", r);
}
num_wait = 0;
}
/* wait while the hostnames are looked up. Do something useful here */
if(num_wait > 0)
for(i=0; i<1000; i++) {
usleep(100000);
fprintf(stderr, "%g seconds passed\n", 0.1*(double)i);
r = ub_process(ctx);
checkerr("ub_process", r);
if(num_wait == 0)
break;
}
if(i>=999) {
printf("timed out\n");
return 0;
}
printf("lookup complete\n");
/* print lookup results */
for(i=0; i<argc; i++) {
print_result(&lookups[i]);
ub_resolve_free(lookups[i].result);
}
ub_ctx_delete(ctx);
free(lookups);
checklock_stop();
return 0;
}
