1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=4 sw=2 sts=2 et cin: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "GetAddrInfo.h"
#include "mozilla/glean/GleanMetrics.h"
#include "mozilla/net/DNSPacket.h"
#include "nsIDNSService.h"
#include "mozilla/Maybe.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/StaticPrefs_network.h"
#ifdef DNSQUERY_AVAILABLE
// There is a bug in windns.h where the type of parameter ppQueryResultsSet for
// DnsQuery_A is dependent on UNICODE being set. It should *always* be
// PDNS_RECORDA, but if UNICODE is set it is PDNS_RECORDW. To get around this
// we make sure that UNICODE is unset.
# undef UNICODE
# include <ws2tcpip.h>
# undef GetAddrInfo
# include <windns.h>
#endif // DNSQUERY_AVAILABLE
namespace mozilla::net {
#define LOG(msg, ...) \
MOZ_LOG(gGetAddrInfoLog, LogLevel::Debug, ("[DNS]: " msg, ##__VA_ARGS__))
nsresult ResolveHTTPSRecordImpl(const nsACString& aHost, uint16_t aFlags,
TypeRecordResultType& aResult, uint32_t& aTTL) {
nsAutoCString host(aHost);
PDNS_RECORD result = nullptr;
nsAutoCString cname;
aTTL = UINT32_MAX;
if (xpc::IsInAutomation() &&
!StaticPrefs::network_dns_native_https_query_in_automation()) {
return NS_ERROR_UNKNOWN_HOST;
}
TimeStamp startTime = TimeStamp::Now();
DNS_STATUS status =
DnsQuery_A(host.get(), nsIDNSService::RESOLVE_TYPE_HTTPSSVC,
DNS_QUERY_STANDARD, nullptr, &result, nullptr);
mozilla::glean::networking::dns_native_https_call_time.AccumulateRawDuration(
TimeStamp::Now() - startTime);
if (status != ERROR_SUCCESS) {
LOG("DnsQuery_A failed with error: %ld\n", status);
return NS_ERROR_UNKNOWN_HOST;
}
// This will free the record if we exit early from this function.
auto freeDnsRecord =
MakeScopeExit([&]() { DnsRecordListFree(result, DnsFreeRecordList); });
auto CheckRecords = [&aResult, &cname, &aTTL](
PDNS_RECORD result,
const nsCString& aHost) -> nsresult {
PDNS_RECORD current = result;
for (current = result; current; current = current->pNext) {
if (strcmp(current->pName, aHost.get()) != 0) {
continue;
}
if (current->wType == nsIDNSService::RESOLVE_TYPE_HTTPSSVC) {
const unsigned char* ptr = (const unsigned char*)&(current->Data);
struct SVCB parsed;
nsresult rv = DNSPacket::ParseHTTPS(current->wDataLength, parsed, 0,
ptr, current->wDataLength, aHost);
if (NS_FAILED(rv)) {
return rv;
}
if (parsed.mSvcDomainName.IsEmpty() && parsed.mSvcFieldPriority == 0) {
// For AliasMode SVCB RRs, a TargetName of "." indicates that the
// service is not available or does not exist.
continue;
}
if (parsed.mSvcFieldPriority == 0) {
// Alias form SvcDomainName must not have the "." value (empty)
if (parsed.mSvcDomainName.IsEmpty()) {
return NS_ERROR_UNEXPECTED;
}
cname = parsed.mSvcDomainName;
ToLowerCase(cname);
break;
}
if (!aResult.is<TypeRecordHTTPSSVC>()) {
aResult = mozilla::AsVariant(CopyableTArray<SVCB>());
}
auto& results = aResult.as<TypeRecordHTTPSSVC>();
results.AppendElement(parsed);
aTTL = std::min<uint32_t>(aTTL, current->dwTtl);
} else if (current->wType == DNS_TYPE_CNAME) {
cname = current->Data.Cname.pNameHost;
ToLowerCase(cname);
aTTL = std::min<uint32_t>(aTTL, current->dwTtl);
break;
}
}
return NS_OK;
};
int32_t loopCount = 64;
while (loopCount > 0 && aResult.is<Nothing>()) {
loopCount--;
nsresult rv = CheckRecords(result, host);
if (NS_FAILED(rv)) {
return rv;
}
if (aResult.is<Nothing>() && !cname.IsEmpty()) {
host = cname;
cname.Truncate();
continue;
}
if (aResult.is<Nothing>()) {
return NS_ERROR_UNKNOWN_HOST;
}
}
// CNAME loop
if (loopCount == 0) {
return NS_ERROR_UNKNOWN_HOST;
}
if (aResult.is<Nothing>()) {
// The call succeeded, but no HTTPS records were found.
return NS_ERROR_UNKNOWN_HOST;
}
if (aTTL == UINT32_MAX) {
aTTL = 60; // Defaults to 60 seconds
}
return NS_OK;
}
void DNSThreadShutdown() {}
} // namespace mozilla::net
|
