utils/samba-dig.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS query too for Samba with socketwrapper support
   5
   6    Copyright (C) 2012 Kai Blin  <kai@samba.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include <talloc.h>
  24 #include <tevent.h>
  25 #include "lib/util/samba_util.h"
  26 #include "librpc/ndr/libndr.h"
  27 #include "librpc/gen_ndr/ndr_dns.h"
  28 #include "libcli/dns/libdns.h"
  29
  30 static void usage(void)
  31 {
  32         printf("Usage: samba-dig <dns-server-ip> <data> <record-type>\n\n");
  33 }
  34
  35 static struct dns_name_packet *make_name_packet(TALLOC_CTX *mem_ctx,
  36                                                 uint16_t operation)
  37 {
  38         struct dns_name_packet *packet = talloc_zero(mem_ctx,
  39                                                      struct dns_name_packet);
  40         if (packet == NULL) {
  41                 return NULL;
  42         }
  43
  44         packet->id = random();
  45         packet->operation |= operation;
  46
  47         return packet;
  48 }
  49
  50 #define QTYPE_MAP(type) if (strncmp(type_string, #type , strlen( #type )) == 0) \
  51         return DNS_QTYPE_ ## type ;
  52
  53 static enum dns_qtype parse_qtype(const char *type_string)
  54 {
  55         QTYPE_MAP(AAAA);
  56         QTYPE_MAP(A);
  57         QTYPE_MAP(SOA);
  58         QTYPE_MAP(PTR);
  59         return -1;
  60 }
  61 #undef QTYPE_MAP
  62
  63 static struct dns_name_question *make_question(TALLOC_CTX *mem_ctx,
  64                                                const char *name,
  65                                                enum dns_qtype type)
  66 {
  67         struct dns_name_question *question = talloc(mem_ctx,
  68                         struct dns_name_question);
  69         if (question == NULL) {
  70                 return NULL;
  71         }
  72
  73         question->name = talloc_strdup(question, name);
  74         question->question_type = type;
  75         question->question_class = DNS_QCLASS_IN;
  76
  77         return question;
  78 }
  79
  80 int main(int argc, char **argv)
  81 {
  82         TALLOC_CTX *mem_ctx = talloc_init("samba-dig");
  83         struct tevent_context *ev;
  84         struct dns_name_packet *dns_packet, *in_packet;
  85         struct dns_name_question *question;
  86         enum dns_qtype type;
  87         enum ndr_err_code ndr_err;
  88         struct tevent_req *req;
  89         WERROR w_err;
  90         DATA_BLOB out, in;
  91         int ret = 0;
  92
  93         if (argc < 4) {
  94                 usage();
  95                 exit(1);
  96         }
  97
  98         ev = tevent_context_init(mem_ctx);
  99         setup_logging("samba-dig", DEBUG_STDERR);
 100         debug_parse_levels("1");
 101
 102         DEBUG(1,("Querying %s for %s %s\n", argv[1], argv[2], argv[3]));
 103
 104         dns_packet = make_name_packet(mem_ctx, DNS_OPCODE_QUERY);
 105
 106         type = parse_qtype(argv[3]);
 107         if (type == -1) {
 108                 DEBUG(0, ("Invalid DNS_QTYPE %s\n", argv[3]));
 109                 ret = 1;
 110                 goto error;
 111         }
 112
 113         question = make_question(dns_packet, argv[2], type);
 114
 115         dns_packet->qdcount = 1;
 116         dns_packet->questions = question;
 117         NDR_PRINT_DEBUG(dns_name_packet, dns_packet);
 118
 119         ndr_err = ndr_push_struct_blob(&out, mem_ctx, dns_packet,
 120                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 121         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 122                 DEBUG(0, ("Failed to marshall dns_name_packet: %d\n", ndr_err));
 123                 ret = 1;
 124                 goto error;
 125         }
 126
 127         req = dns_udp_request_send(mem_ctx, ev, argv[1], out.data, out.length);
 128         if (req == NULL) {
 129                 DEBUG(0, ("Failed to allocate memory for tevent_req\n"));
 130                 ret = 1;
 131                 goto error;
 132         }
 133         if (!tevent_req_poll(req, ev)) {
 134                 DEBUG(0, ("Error sending dns request\n"));
 135                 ret = 1;
 136                 goto error;
 137         }
 138         w_err = dns_udp_request_recv(req, mem_ctx, &in.data, &in.length);
 139         if (!W_ERROR_IS_OK(w_err)) {
 140                 DEBUG(0, ("Error receiving dns request: %s\n", win_errstr(w_err)));
 141                 ret = 1;
 142                 goto error;
 143         }
 144
 145         in_packet = talloc(mem_ctx, struct dns_name_packet);
 146
 147         ndr_err = ndr_pull_struct_blob(&in, in_packet, in_packet,
 148                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 149         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 150                 DEBUG(0, ("Failed to unmarshall dns_name_packet: %d\n", ndr_err));
 151                 ret = 1;
 152                 goto error;
 153         }
 154
 155         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 156
 157 error:
 158         talloc_free(mem_ctx);
 159         return ret;
 160 }