Stub binary for fuzzing DNS resolver.

net/tools/dns_fuzz_stub/dns_fuzz_stub.cc

Index: net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
diff --git a/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc b/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f2be09f42d9ef8d882b31cf5d8e003362578d2a6
--- /dev/null
+++ b/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
@@ -0,0 +1,114 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "base/time.h"
+#include "base/scoped_array.h"
+#include "net/base/address_list.h"
+#include "net/base/dns_util.h"
+#include "net/base/io_buffer.h"
+#include "net/base/ip_endpoint.h"
+#include "net/dns/dns_protocol.h"
+#include "net/dns/dns_query.h"
+#include "net/dns/dns_response.h"
+
+namespace {
+
+int Usage(const char* program_name) {
+  LOG(ERROR) << "Usage: " << program_name << " test_case_filename";
+  return 1;
+}
+
+int InvalidTestCase(const char* program_name) {
+  LOG(ERROR) << "Test case format invalid";
+  return 2;
+}
+
+// TODO(ttuttle): This should read from the file, probably in JSON.
+bool ReadTestCase(const char* filename,
+                  uint16_t* id, std::string* qname, uint16_t* qtype,
+                  size_t* resp_len, char** resp_buf) {

[szym, 2012/05/31 21:43:10]

Consider using std::vector<char>* instead of char** + size_t*.

[Deprecated (see juliatuttle), 2012/05/31 22:11:56]

Done.

+  static const unsigned char resp[] = {
+    0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+    0x01, 0x61, 0x00, 0x00, 0x01, 0x00, 0x01,
+    0x01, 0x61, 0x00, 0x00, 0x01, 0x00, 0x01,
+    0x00, 0x00, 0x00, 0xff, 0x00, 0x04, 0x0a, 0x0a, 0x0a, 0x0a };
+
+  *id = 0x0000;
+  *qname = "a";
+  *qtype = 0x0001;
+
+  *resp_len = sizeof(resp);
+  *resp_buf = new char[arraysize(resp)];
+  memcpy(*resp_buf, resp, sizeof(resp));

[szym, 2012/05/31 21:43:10]

If you go with std::vector, this can be done with insert().

[Deprecated (see juliatuttle), 2012/05/31 22:11:56]

Done.

+
+  return true;
+}
+
+}
+
+int main(int argc, char** argv) {
+  if (argc != 2)
+    return Usage(argv[0]);
+
+  const char* filename = argv[1];
+
+  LOG(INFO) << "Test case: " << filename;
+
+  uint16_t id;
+  std::string qname_dotted;
+  uint16_t qtype;
+  size_t resp_len;
+  scoped_array<char> resp;
+  char* resp_buf;
+
+  if (!ReadTestCase(filename,
+                    &id, &qname_dotted, &qtype,
+                    &resp_len, &resp_buf)) {
+    return InvalidTestCase(argv[0]);
+  }
+
+  resp.reset(resp_buf);

[szym, 2012/05/31 21:43:10]

It's probably cleaner to pass &resp (scoped_array*) to ReadTestCase, but
probably easiest to just use std::vector as suggested above.

[Deprecated (see juliatuttle), 2012/05/31 22:11:56]

Done.

+
+  LOG(INFO) << "Query: id=" << id
+            << " qname=" << qname_dotted
+            << " qtype=" << qtype;
+  LOG(INFO) << "Response: " << resp_len << " bytes";
+
+  std::string qname;
+  if (!net::DNSDomainFromDot(qname_dotted, &qname)) {
+    LOG(ERROR) << "DNSDomainFromDot(" << qname_dotted << ") failed.";
+    return 3;
+  }
+
+  net::DnsQuery query(id, qname, qtype);
+  net::DnsResponse response;
+  memcpy(response.io_buffer()->data(), resp_buf, resp_len);

[Deprecated (see juliatuttle), 2012/05/31 22:11:56]

std::copy! :D  Also, implicit conversion from an array to an iterator on that
array! :D

+
+  if (!response.InitParse(resp_len, query)) {
+    LOG(INFO) << "InitParse failed.";
+    return 0;
+  }
+
+  net::AddressList address_list;
+  base::TimeDelta ttl;
+  net::DnsResponse::Result result = response.ParseToAddressList(
+      &address_list, &ttl);
+  if (result != net::DnsResponse::DNS_SUCCESS) {
+    LOG(INFO) << "ParseToAddressList failed: " << result;
+    return 0;
+  }
+
+  LOG(INFO) << "Address List:";
+  for (unsigned int i = 0; i < address_list.size(); i++) {
+    LOG(INFO) << "\t" << address_list[i].ToString();
+  }
+  LOG(INFO) << "TTL: " << ttl.InSeconds() << " seconds";
+
+  return 0;
+}
+