diff options
Diffstat (limited to 'src/common/dns_utils.cpp')
| -rw-r--r-- | src/common/dns_utils.cpp | 45 |
1 files changed, 39 insertions, 6 deletions
diff --git a/src/common/dns_utils.cpp b/src/common/dns_utils.cpp index 1310b8bfd..f549218cb 100644 --- a/src/common/dns_utils.cpp +++ b/src/common/dns_utils.cpp @@ -40,6 +40,8 @@ namespace bf = boost::filesystem; #undef MONERO_DEFAULT_LOG_CATEGORY #define MONERO_DEFAULT_LOG_CATEGORY "net.dns" +#define DEFAULT_DNS_PUBLIC_ADDR "8.8.4.4" + static boost::mutex instance_lock; namespace @@ -197,16 +199,19 @@ public: DNSResolver::DNSResolver() : m_data(new DNSResolverData()) { int use_dns_public = 0; - const char* dns_public_addr = "8.8.4.4"; + std::string dns_public_addr = DEFAULT_DNS_PUBLIC_ADDR; if (auto res = getenv("DNS_PUBLIC")) { - std::string dns_public(res); - // TODO: could allow parsing of IP and protocol: e.g. DNS_PUBLIC=tcp:8.8.8.8 - if (dns_public == "tcp") + dns_public_addr = tools::dns_utils::parse_dns_public(res); + if (!dns_public_addr.empty()) { - LOG_PRINT_L0("Using public DNS server: " << dns_public_addr << " (TCP)"); + MGINFO("Using public DNS server: " << dns_public_addr << " (TCP)"); use_dns_public = 1; } + else + { + MERROR("Failed to parse DNS_PUBLIC"); + } } // init libunbound context @@ -214,7 +219,7 @@ DNSResolver::DNSResolver() : m_data(new DNSResolverData()) if (use_dns_public) { - ub_ctx_set_fwd(m_data->m_ub_context, string_copy(dns_public_addr)); + ub_ctx_set_fwd(m_data->m_ub_context, dns_public_addr.c_str()); ub_ctx_set_option(m_data->m_ub_context, string_copy("do-udp:"), string_copy("no")); ub_ctx_set_option(m_data->m_ub_context, string_copy("do-tcp:"), string_copy("yes")); } @@ -519,6 +524,34 @@ bool load_txt_records_from_dns(std::vector<std::string> &good_records, const std return true; } +std::string parse_dns_public(const char *s) +{ + unsigned ip0, ip1, ip2, ip3; + char c; + std::string dns_public_addr; + if (!strcmp(s, "tcp")) + { + dns_public_addr = DEFAULT_DNS_PUBLIC_ADDR; + LOG_PRINT_L0("Using default public DNS server: " << dns_public_addr << " (TCP)"); + } + else if (sscanf(s, "tcp://%u.%u.%u.%u%c", &ip0, &ip1, &ip2, &ip3, &c) == 4) + { + if (ip0 > 255 || ip1 > 255 || ip2 > 255 || ip3 > 255) + { + MERROR("Invalid IP: " << s << ", using default"); + } + else + { + dns_public_addr = std::string(s + strlen("tcp://")); + } + } + else + { + MERROR("Invalid DNS_PUBLIC contents, ignored"); + } + return dns_public_addr; +} + } // namespace tools::dns_utils } // namespace tools |