src/fuzz/fuzz-dns-packet.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2018 Jonathan Rudenberg
   4
   5   systemd is free software; you can redistribute it and/or modify it
   6   under the terms of the GNU Lesser General Public License as published by
   7   the Free Software Foundation; either version 2.1 of the License, or
   8   (at your option) any later version.
   9
  10   systemd is distributed in the hope that it will be useful, but
  11   WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13   Lesser General Public License for more details.
  14
  15   You should have received a copy of the GNU Lesser General Public License
  16   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  17 ***/
  18
  19 #include "fuzz.h"
  20 #include "resolved-dns-packet.h"
  21
  22 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  23         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
  24
  25         if (size > DNS_PACKET_SIZE_MAX)
  26                 return 0;
  27
  28         assert_se(dns_packet_new(&p, DNS_PROTOCOL_DNS, 0, DNS_PACKET_SIZE_MAX) >= 0);
  29         p->size = 0; /* by default append starts after the header, undo that */
  30         assert_se(dns_packet_append_blob(p, data, size, NULL) >= 0);
  31         if (size < DNS_PACKET_HEADER_SIZE) {
  32                 /* make sure we pad the packet back up to the minimum header size */
  33                 assert_se(p->allocated >= DNS_PACKET_HEADER_SIZE);
  34                 memzero(DNS_PACKET_DATA(p) + size, DNS_PACKET_HEADER_SIZE - size);
  35                 p->size = DNS_PACKET_HEADER_SIZE;
  36         }
  37         (void) dns_packet_extract(p);
  38
  39         return 0;
  40 }