#include #include #include #include /* 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; (void) context; /* unused parameter */ 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 response"); else if (status != GETDNS_RESPSTATUS_GOOD) fprintf(stderr, "The search had no results, and a return value of %"PRIu32".\n", status); 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 (!(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 (!(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); } int main() { getdns_return_t r; /* Holder for all function returns */ getdns_context *context = NULL; struct event_base *event_base = NULL; getdns_dict *extensions = NULL; char *query_name = "www.example.com"; /* Could add things here to help identify this call */ char *userarg = query_name; getdns_transaction_t transaction_id; if ((r = getdns_context_create(&context, 1))) fprintf(stderr, "Trying to create the context failed"); 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 = getdns_address( context, query_name, extensions , userarg, &transaction_id, callback))) fprintf(stderr, "Error scheduling asynchronous request"); 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); }