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// Copyright (c) 2011 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 "net/base/dns_response.h"
#include "base/bind.h"
#include "base/rand_util.h"
#include "net/base/dns_util.h"
#include "net/base/net_errors.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace net {
// DNS response consists of a header followed by a question followed by
// answer. Header format, question format and response format are
// described below. For the meaning of specific fields, please see RFC
// 1035.
// Header format.
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ID |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// |QR| Opcode |AA|TC|RD|RA| Z | RCODE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QDCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ANCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | NSCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ARCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// Question format.
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | |
// / QNAME /
// / /
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QTYPE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QCLASS |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// Answser format.
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | |
// / /
// / NAME /
// | |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | TYPE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | CLASS |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | TTL |
// | |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | RDLENGTH |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
// / RDATA /
// / /
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// TODO(agayev): add more thorough tests.
TEST(DnsResponseTest, ResponseWithCnameA) {
const std::string kQname("\012codereview\010chromium\003org", 25);
DnsQuery q1(kQname, kDNS_A, base::Bind(&base::RandInt));
uint8 id_hi = q1.id() >> 8, id_lo = q1.id() & 0xff;
uint8 ip[] = { // codereview.chromium.org resolves to
0x4a, 0x7d, 0x5f, 0x79 // 74.125.95.121
};
IPAddressList expected_ips;
expected_ips.push_back(IPAddressNumber(ip, ip + arraysize(ip)));
uint8 response_data[] = {
// Header
id_hi, id_lo, // ID
0x81, 0x80, // Standard query response, no error
0x00, 0x01, // 1 question
0x00, 0x02, // 2 RRs (answers)
0x00, 0x00, // 0 authority RRs
0x00, 0x00, // 0 additional RRs
// Question
0x0a, 0x63, 0x6f, 0x64, // This part is echoed back from the
0x65, 0x72, 0x65, 0x76, // respective query.
0x69, 0x65, 0x77, 0x08,
0x63, 0x68, 0x72, 0x6f,
0x6d, 0x69, 0x75, 0x6d,
0x03, 0x6f, 0x72, 0x67,
0x00,
0x00, 0x01,
0x00, 0x01,
// Answer 1
0xc0, 0x0c, // NAME is a pointer to name in Question section.
0x00, 0x05, // TYPE is CNAME.
0x00, 0x01, // CLASS is IN.
0x00, 0x01, // TTL (4 bytes) is 20 hours, 47 minutes, 48 seconds.
0x24, 0x74,
0x00, 0x12, // RDLENGTH is 18 bytse.
0x03, 0x67, 0x68, 0x73, // ghs.l.google.com in DNS format.
0x01, 0x6c, 0x06, 0x67,
0x6f, 0x6f, 0x67, 0x6c,
0x65, 0x03, 0x63, 0x6f,
0x6d, 0x00,
// Answer 2
0xc0, 0x35, // NAME is a pointer to name in Question section.
0x00, 0x01, // TYPE is A.
0x00, 0x01, // CLASS is IN.
0x00, 0x00, // TTL (4 bytes) is 53 seconds.
0x00, 0x35,
0x00, 0x04, // RDLENGTH is 4 bytes.
ip[0], ip[1], ip[2], ip[3], // RDATA is the IP.
};
// Create a response object and simulate reading into it.
DnsResponse r1(&q1);
memcpy(r1.io_buffer()->data(), &response_data[0],
r1.io_buffer()->size());
// Verify resolved IPs.
int response_size = arraysize(response_data);
IPAddressList actual_ips;
EXPECT_EQ(OK, r1.Parse(response_size, &actual_ips));
EXPECT_EQ(expected_ips, actual_ips);
}
} // namespace net
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