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/* This program is based on (IIRC)
* getdns/spec/example/example-simple-answers.c.
*
* Resolve DNS name argv[1] of type argv[2] using libgetdns and write
* the resulting RRs to two files, in DNS binary wire format:
*
* - binout: /just_address_answers/0/address_data and
* /just_address_answers/1/address_data
*
* - treeout: output from getdns_rr_dict2wire for all RR's in the
* answer section
*
* Based on getdns/spec/example/example-simple-answers.c.
*/
#include <assert.h>
#include <inttypes.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <getdns/getdns.h>
#include <getdns/getdns_ext_libevent.h>
#include <event2/event.h>
static int debug = 1;
static getdns_return_t
dump_reply(FILE *fp, getdns_dict *reply, const char *section_name)
{
getdns_list *section = NULL;
size_t section_len = -1;
getdns_return_t r;
uint8_t res_buf[4096], *res = NULL;
size_t res_len = sizeof(res_buf);
r = getdns_dict_get_list(reply, section_name, §ion);
if (r) {
fprintf(stderr,
"unable to get section \"%s\" from reply\n",
section_name);
return r;
}
r = getdns_list_get_length(section, §ion_len);
if (r) {
fprintf(stderr, "unable to get length of section\n");
return r;
}
for (size_t j = 0; j < section_len; j++) {
getdns_dict *rr = NULL;
r = getdns_list_get_dict(section, j , &rr);
if (r) {
fprintf(stderr, "unable to get rr from entry "
"%d: %d\n", j, r);
return r;
}
r = getdns_rr_dict2wire(rr, &res, &res_len);
if (r) {
fprintf(stderr,
"unable to convert entry %d "
"to wire format: %d\n", j, r);
return r;
}
if (0 && debug) {
char *s = getdns_pretty_print_dict(rr);
puts(s);
free(s);
}
if (fwrite(res, 1, res_len, fp) != res_len) {
fprintf(stderr,
"unable to write buffer to file: %s\n",
strerror(errno));
return -errno;
}
free(res);
}
return 0;
}
int
dump_tree(FILE *fp, const getdns_dict *response, const char *tree_name)
{
getdns_return_t r;
getdns_list *tree = NULL;
size_t n_replies = -1;
r = getdns_dict_get_list(response, tree_name, &tree);
if (r) {
fprintf(stderr, "unable to get tree %s\n", tree_name);
return r;
}
r = getdns_list_get_length(tree, &n_replies);
if (r) {
fprintf(stderr, "unable to get number of replies\n");
return r;
}
for (size_t i = 0; i < n_replies; i++) {
getdns_dict *reply = NULL;
r = getdns_list_get_dict(tree, i, &reply);
if (r) {
fprintf(stderr, "unable to get reply %d from tree\n", i);
return r;
}
if (debug) {
char *s = getdns_pretty_print_dict(reply);
printf("Pretty-printing reply #%d:%s\n", i, s);
free(s);
}
dump_reply(fp, reply, "answer");
}
return 0;
}
/* Set up the callback function, which will also do the processing of the results */
void callback(getdns_context *context,
getdns_callback_type_t callback_type,
getdns_dict *response,
void *userarg,
getdns_transaction_t transaction_id)
{
getdns_return_t r; /* Holder for all function returns */
uint32_t status;
getdns_bindata *address_data;
char *first = NULL, *second = NULL;
FILE *binoutfp = NULL, *treeoutfp = NULL;
(void) context; /* unused parameter */
binoutfp = fopen("binout", "w");
assert(binoutfp != NULL);
treeoutfp = fopen("treeout", "w");
assert(treeoutfp != NULL);
printf( "Callback for query \"%s\" with request ID %"PRIu64".\n"
, (char *)userarg, transaction_id );
switch(callback_type) {
case GETDNS_CALLBACK_CANCEL:
printf("Transaction with ID %"PRIu64" was cancelled.\n", transaction_id);
return;
case GETDNS_CALLBACK_TIMEOUT:
printf("Transaction with ID %"PRIu64" timed out.\n", transaction_id);
return;
case GETDNS_CALLBACK_ERROR:
printf("An error occurred for transaction ID %"PRIu64".\n", transaction_id);
return;
default: break;
}
assert( callback_type == GETDNS_CALLBACK_COMPLETE );
if ((r = getdns_dict_get_int(response, "status", &status)))
fprintf(stderr, "Could not get \"status\" from reponse");
else if (status != GETDNS_RESPSTATUS_GOOD)
fprintf(stderr, "The search had no results, and a return value of %"PRIu32".\n", status);
static char *TREES[] = {"replies_tree", "validation_chain"};
static const int TREES_LEN = 2;
for (int i = 0; i < TREES_LEN; i++) {
if (dump_tree(treeoutfp, response, TREES[i]))
fprintf(stderr, "Could not dump %s to file\n", TREES[i]);
else if ((r = getdns_dict_get_bindata(response, "/just_address_answers/0/address_data", &address_data)))
fprintf(stderr, "Could not get first address");
else if (fwrite(address_data->data, 1, address_data->size, binoutfp) !=
address_data->size)
fprintf(stderr, "first fwrite: %s\n", strerror(errno));
else if (!(first = getdns_display_ip_address(address_data)))
fprintf(stderr, "Could not convert first address to string\n");
else if ((r = getdns_dict_get_bindata(response, "/just_address_answers/1/address_data", &address_data)))
fprintf(stderr, "Could not get second address");
else if (fwrite(address_data->data, 1, address_data->size, binoutfp) !=
address_data->size)
fprintf(stderr, "second fwrite: %s\n", strerror(errno));
else if (!(second = getdns_display_ip_address(address_data)))
fprintf(stderr, "Could not convert second address to string\n");
if (first) {
printf("The address is %s\n", first);
free(first);
}
if (second) {
printf("The address is %s\n", second);
free(second);
}
if (r) {
assert( r != GETDNS_RETURN_GOOD );
fprintf(stderr, ": %d\n", r);
}
}
getdns_dict_destroy(response);
if (binoutfp) fclose(binoutfp);
if (treeoutfp) fclose(treeoutfp);
}
static getdns_return_t
send_query(getdns_context *context,
char *query_name,
const uint16_t query_type,
getdns_transaction_t *transaction_id)
{
getdns_return_t r = GETDNS_RETURN_GENERIC_ERROR;
getdns_dict *extensions = getdns_dict_create();
char *userarg = query_name;
assert(extensions != NULL);
r = getdns_dict_set_int(extensions,
"dnssec_return_validation_chain",
GETDNS_EXTENSION_TRUE);
if (r) return r;
#if 0
r = getdns_dict_set_int(extensions,
"dnssec_return_status",
GETDNS_EXTENSION_TRUE);
if (r) return r;
#endif
if (query_type == 0)
r = getdns_address(context, query_name, extensions, userarg,
transaction_id, callback);
else
r = getdns_general(context, query_name, query_type,
extensions, userarg,
transaction_id, callback);
if (r) return r;
return r;
}
int main(int argc, char *argv[])
{
getdns_return_t r; /* Holder for all function returns */
getdns_context *context = NULL;
struct event_base *event_base = NULL;
char *query_name = "www.example.com";
uint16_t query_type = 0;
getdns_transaction_t transaction_id;
getdns_list *trust_anchors;
if (argc > 1)
query_name = argv[1];
if (argc > 2)
query_type = (uint16_t) atoi(argv[2]);
if ((r = getdns_context_create(&context, 1)))
fprintf(stderr, "Trying to create the context failed");
else if ((r = getdns_context_get_dnssec_trust_anchors(
context, &trust_anchors)) ||
trust_anchors == NULL)
fprintf(stderr, "No trust anchor.\n");
else if (!(event_base = event_base_new()))
fprintf(stderr, "Trying to create the event base failed.\n");
else if ((r = getdns_extension_set_libevent_base(context, event_base)))
fprintf(stderr, "Setting the event base failed");
else if ((r = send_query(context, query_name, query_type,
&transaction_id)))
fprintf(stderr, "Queueing query failed: %d\n", r);
else {
printf("Request with transaction ID %"PRIu64" scheduled.\n",
transaction_id);
if (event_base_dispatch(event_base) < 0)
fprintf(stderr, "Error dispatching events\n");
}
/* Clean up */
if (event_base)
event_base_free(event_base);
if (context)
getdns_context_destroy(context);
/* Assuming we get here, leave gracefully */
exit(EXIT_SUCCESS);
}
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