| // Copyright 2018 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/dns/public/util.h" |
| |
| #include <set> |
| #include <unordered_map> |
| |
| #include "base/logging.h" |
| #include "build/build_config.h" |
| #include "net/base/ip_address.h" |
| #include "net/dns/public/dns_protocol.h" |
| #include "net/third_party/uri_template/uri_template.h" |
| #include "url/gurl.h" |
| |
| namespace net { |
| |
| namespace { |
| IPEndPoint GetMdnsIPEndPoint(const char* address) { |
| IPAddress multicast_group_number; |
| bool success = multicast_group_number.AssignFromIPLiteral(address); |
| DCHECK(success); |
| return IPEndPoint(multicast_group_number, |
| dns_protocol::kDefaultPortMulticast); |
| } |
| } // namespace |
| |
| namespace dns_util { |
| |
| bool IsValidDoHTemplate(const string& server_template, |
| const string& server_method) { |
| std::string url_string; |
| std::string test_query = "this_is_a_test_query"; |
| std::unordered_map<std::string, std::string> template_params( |
| {{"dns", test_query}}); |
| std::set<std::string> vars_found; |
| bool valid_template = uri_template::Expand(server_template, template_params, |
| &url_string, &vars_found); |
| if (!valid_template) { |
| // The URI template is malformed. |
| return false; |
| } |
| if (server_method != "POST" && vars_found.find("dns") == vars_found.end()) { |
| // GET requests require the template to have a dns variable. |
| return false; |
| } |
| GURL url(url_string); |
| if (!url.is_valid() || !url.SchemeIs("https")) { |
| // The expanded template must be a valid HTTPS URL. |
| return false; |
| } |
| if (url.host().find(test_query) != std::string::npos) { |
| // The dns variable may not be part of the hostname. |
| return false; |
| } |
| return true; |
| } |
| |
| IPEndPoint GetMdnsGroupEndPoint(AddressFamily address_family) { |
| switch (address_family) { |
| case ADDRESS_FAMILY_IPV4: |
| return GetMdnsIPEndPoint(dns_protocol::kMdnsMulticastGroupIPv4); |
| case ADDRESS_FAMILY_IPV6: |
| return GetMdnsIPEndPoint(dns_protocol::kMdnsMulticastGroupIPv6); |
| default: |
| NOTREACHED(); |
| return IPEndPoint(); |
| } |
| } |
| |
| IPEndPoint GetMdnsReceiveEndPoint(AddressFamily address_family) { |
| // TODO(qingsi): MacOS should follow other POSIX platforms in the else-branch |
| // after addressing crbug.com/899310. We have encountered a conflicting issue on |
| // CrOS as described in crbug.com/931916, and the following is a temporary |
| // mitigation to reconcile the two issues. Remove this after closing |
| // crbug.com/899310. |
| #if defined(OS_WIN) || defined(OS_FUCHSIA) || defined(OS_MACOSX) |
| // With Windows, binding to a mulitcast group address is not allowed. |
| // Multicast messages will be received appropriate to the multicast groups the |
| // socket has joined. Sockets intending to receive multicast messages should |
| // bind to a wildcard address (e.g. 0.0.0.0). |
| switch (address_family) { |
| case ADDRESS_FAMILY_IPV4: |
| return IPEndPoint(IPAddress::IPv4AllZeros(), |
| dns_protocol::kDefaultPortMulticast); |
| case ADDRESS_FAMILY_IPV6: |
| return IPEndPoint(IPAddress::IPv6AllZeros(), |
| dns_protocol::kDefaultPortMulticast); |
| default: |
| NOTREACHED(); |
| return IPEndPoint(); |
| } |
| #else // !(defined(OS_WIN) || defined(OS_FUCHSIA)) || defined(OS_MACOSX) |
| // With POSIX, any socket can receive messages for multicast groups joined by |
| // any socket on the system. Sockets intending to receive messages for a |
| // specific multicast group should bind to that group address. |
| return GetMdnsGroupEndPoint(address_family); |
| #endif // !(defined(OS_WIN) || defined(OS_FUCHSIA)) || defined(OS_MACOSX) |
| } |
| |
| } // namespace dns_util |
| } // namespace net |