diff options
| -rw-r--r-- | src/0tDNS.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/0tDNS.c b/src/0tDNS.c new file mode 100644 index 0000000..838cae6 --- /dev/null +++ b/src/0tDNS.c @@ -0,0 +1,121 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> +#include <unbound.h> + +/* examine the result structure in detail */ +void examine_result(const char *query, struct ub_result *result) +{ + int i; + int num; + + printf("The query is for: %s\n", query); + printf("The result has:\n"); + printf("qname: %s\n", result->qname); + printf("qtype: %d\n", result->qtype); + printf("qclass: %d\n", result->qclass); + if(result->canonname) + printf("canonical name: %s\n", + result->canonname); + else printf("canonical name: <none>\n"); + + if(result->havedata) + printf("has data\n"); + else printf("has no data\n"); + + if(result->nxdomain) + printf("nxdomain (name does not exist)\n"); + else printf("not an nxdomain (name exists)\n"); + + if(result->secure) + printf("validated to be secure\n"); + else printf("not validated as secure\n"); + + if(result->bogus) + printf("a security failure! (bogus)\n"); + else printf("not a security failure (not bogus)\n"); + + printf("DNS rcode: %d\n", result->rcode); + + num = 0; + for(i=0; result->data[i]; i++) { + printf("result data element %d has length %d\n", + i, result->len[i]); + printf("result data element %d is: %s\n", + i, inet_ntoa(*(struct in_addr*)result->data[i])); + num++; + } + printf("result has %d data element(s)\n", num); +} + +struct ub_ctx *ztdns_create_context_with_resolver(const char *resolver_addr) { + int rc; + struct ub_ctx* ctx; + ctx = ub_ctx_create(); + if (!ctx) { + fprintf(stderr, "Couldn't create libunbound context.\n"); + return NULL; + } + rc = ub_ctx_set_fwd(ctx, resolver_addr); + if (rc) { + fprintf(stderr, "Couldn't set forward server: %s\n", + ub_strerror(rc)); + return NULL; + } + return ctx; +} + +void ztdns_try_resolve(struct ub_ctx *ctx, const char *name) { + struct ub_result* result; + int rc; + rc = ub_resolve(ctx, name, + 1 /* TYPE A (IPv4 address) */, + 1 /* CLASS IN (internet) */, &result); + if(rc) + printf("resolve error: %s\n", ub_strerror(rc)); + else + examine_result(name, result); + ub_resolve_free(result); +} + +int main(int argc, char** argv) +{ + struct ub_ctx + *ctx_google1 = NULL, + *ctx_google2 = NULL, + *ctx_cloudflare = NULL; + int rc = EXIT_SUCCESS; + + if(argc != 2) { + printf("usage: <hostname>\n"); + return EXIT_FAILURE; + } + + ctx_google1 = ztdns_create_context_with_resolver("8.8.8.8"); + ctx_google2 = ztdns_create_context_with_resolver("8.8.4.4"); + ctx_cloudflare = ztdns_create_context_with_resolver("1.1.1.1"); + + if (!ctx_google1 || !ctx_google2 || !ctx_cloudflare) { + rc = EXIT_FAILURE; + goto abort; + } + + printf("* VIA GOOGLE (8.8.8.8)\n"); + ztdns_try_resolve(ctx_google1, argv[1]); + printf("* VIA GOOGLE (8.8.4.4)\n"); + ztdns_try_resolve(ctx_google2, argv[1]); + printf("* VIA CLOUDFLARE (1.1.1.1)\n"); + ztdns_try_resolve(ctx_cloudflare, argv[1]); + +abort: + if (ctx_google1) + ub_ctx_delete(ctx_google1); + if (ctx_google2) + ub_ctx_delete(ctx_google2); + if (ctx_cloudflare) + ub_ctx_delete(ctx_cloudflare); + + return rc; +} |