1 /*
2  * nghttp2 - HTTP/2 C Library
3  *
4  * Copyright (c) 2016 Tatsuhiro Tsujikawa
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining
7  * a copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sublicense, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be
15  * included in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  */
25 #include "shrpx_dual_dns_resolver.h"
26 
27 namespace shrpx {
28 
DualDNSResolver(struct ev_loop * loop)29 DualDNSResolver::DualDNSResolver(struct ev_loop *loop)
30     : resolv4_(loop), resolv6_(loop) {
31   auto cb = [this](DNSResolverStatus, const Address *) {
32     Address result;
33 
34     auto status = this->get_status(&result);
35     switch (status) {
36     case DNSResolverStatus::ERROR:
37     case DNSResolverStatus::OK:
38       break;
39     default:
40       return;
41     }
42 
43     auto cb = this->get_complete_cb();
44     cb(status, &result);
45   };
46 
47   resolv4_.set_complete_cb(cb);
48   resolv6_.set_complete_cb(cb);
49 }
50 
resolve(const StringRef & host)51 int DualDNSResolver::resolve(const StringRef &host) {
52   int rv4, rv6;
53   rv4 = resolv4_.resolve(host, AF_INET);
54   rv6 = resolv6_.resolve(host, AF_INET6);
55 
56   if (rv4 != 0 && rv6 != 0) {
57     return -1;
58   }
59 
60   return 0;
61 }
62 
get_complete_cb() const63 CompleteCb DualDNSResolver::get_complete_cb() const { return complete_cb_; }
64 
set_complete_cb(CompleteCb cb)65 void DualDNSResolver::set_complete_cb(CompleteCb cb) { complete_cb_ = cb; }
66 
get_status(Address * result) const67 DNSResolverStatus DualDNSResolver::get_status(Address *result) const {
68   auto rv6 = resolv6_.get_status(result);
69   if (rv6 == DNSResolverStatus::OK) {
70     return DNSResolverStatus::OK;
71   }
72   auto rv4 = resolv4_.get_status(result);
73   if (rv4 == DNSResolverStatus::OK) {
74     return DNSResolverStatus::OK;
75   }
76   if (rv4 == DNSResolverStatus::RUNNING || rv6 == DNSResolverStatus::RUNNING) {
77     return DNSResolverStatus::RUNNING;
78   }
79   if (rv4 == DNSResolverStatus::ERROR || rv6 == DNSResolverStatus::ERROR) {
80     return DNSResolverStatus::ERROR;
81   }
82   return DNSResolverStatus::IDLE;
83 }
84 
85 } // namespace shrpx
86