#include <network/dns_handler.hpp> #include <network/resolver.hpp> #include <string.h> #include <arpa/inet.h> #include <netinet/in.h> #include <cstdlib> using namespace std::string_literals; Resolver::Resolver(): #ifdef CARES_FOUND resolved4(false), resolved6(false), resolving(false), cares_addrinfo(nullptr), port{}, #endif resolved(false), error_msg{} { } void Resolver::resolve(const std::string& hostname, const std::string& port, SuccessCallbackType success_cb, ErrorCallbackType error_cb) { this->error_cb = error_cb; this->success_cb = success_cb; #ifdef CARES_FOUND this->port = port; #endif this->start_resolving(hostname, port); } #ifdef CARES_FOUND void Resolver::start_resolving(const std::string& hostname, const std::string&) { this->resolving = true; this->resolved = false; this->resolved4 = false; this->resolved6 = false; this->error_msg.clear(); this->cares_addrinfo = nullptr; auto hostname4_resolved = [](void* arg, int status, int, struct hostent* hostent) { Resolver* resolver = static_cast<Resolver*>(arg); resolver->on_hostname4_resolved(status, hostent); }; auto hostname6_resolved = [](void* arg, int status, int, struct hostent* hostent) { Resolver* resolver = static_cast<Resolver*>(arg); resolver->on_hostname6_resolved(status, hostent); }; DNSHandler::instance.gethostbyname(hostname, hostname6_resolved, this, AF_INET6); DNSHandler::instance.gethostbyname(hostname, hostname4_resolved, this, AF_INET); } void Resolver::on_hostname4_resolved(int status, struct hostent* hostent) { this->resolved4 = true; if (status == ARES_SUCCESS) this->fill_ares_addrinfo4(hostent); else this->error_msg = ::ares_strerror(status); if (this->resolved4 && this->resolved6) this->on_resolved(); } void Resolver::on_hostname6_resolved(int status, struct hostent* hostent) { this->resolved6 = true; if (status == ARES_SUCCESS) this->fill_ares_addrinfo6(hostent); else this->error_msg = ::ares_strerror(status); if (this->resolved4 && this->resolved6) this->on_resolved(); } void Resolver::on_resolved() { this->resolved = true; this->resolving = false; if (!this->cares_addrinfo) { if (this->error_cb) this->error_cb(this->error_msg.data()); } else { this->addr.reset(this->cares_addrinfo); if (this->success_cb) this->success_cb(this->addr.get()); } } void Resolver::fill_ares_addrinfo4(const struct hostent* hostent) { struct addrinfo* prev = this->cares_addrinfo; struct in_addr** address = reinterpret_cast<struct in_addr**>(hostent->h_addr_list); while (*address) { // Create a new addrinfo list element, and fill it struct addrinfo* current = new struct addrinfo; current->ai_flags = 0; current->ai_family = hostent->h_addrtype; current->ai_socktype = SOCK_STREAM; current->ai_protocol = 0; current->ai_addrlen = sizeof(struct sockaddr_in); struct sockaddr_in* ai_addr = new struct sockaddr_in; ai_addr->sin_family = hostent->h_addrtype; ai_addr->sin_port = htons(std::strtoul(this->port.data(), nullptr, 10)); ai_addr->sin_addr.s_addr = (*address)->s_addr; current->ai_addr = reinterpret_cast<struct sockaddr*>(ai_addr); current->ai_next = nullptr; current->ai_canonname = nullptr; current->ai_next = prev; this->cares_addrinfo = current; prev = current; ++address; } } void Resolver::fill_ares_addrinfo6(const struct hostent* hostent) { struct addrinfo* prev = this->cares_addrinfo; struct in6_addr** address = reinterpret_cast<struct in6_addr**>(hostent->h_addr_list); while (*address) { // Create a new addrinfo list element, and fill it struct addrinfo* current = new struct addrinfo; current->ai_flags = 0; current->ai_family = hostent->h_addrtype; current->ai_socktype = SOCK_STREAM; current->ai_protocol = 0; current->ai_addrlen = sizeof(struct sockaddr_in6); struct sockaddr_in6* ai_addr = new struct sockaddr_in6; ai_addr->sin6_family = hostent->h_addrtype; ai_addr->sin6_port = htons(std::strtoul(this->port.data(), nullptr, 10)); ::memcpy(ai_addr->sin6_addr.s6_addr, (*address)->s6_addr, sizeof(ai_addr->sin6_addr.s6_addr)); ai_addr->sin6_flowinfo = 0; ai_addr->sin6_scope_id = 0; current->ai_addr = reinterpret_cast<struct sockaddr*>(ai_addr); current->ai_canonname = nullptr; current->ai_next = prev; this->cares_addrinfo = current; prev = current; ++address; } } #else // ifdef CARES_FOUND void Resolver::start_resolving(const std::string& hostname, const std::string& port) { // If the resolution fails, the addr will be unset this->addr.reset(nullptr); struct addrinfo hints; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_flags = 0; hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; struct addrinfo* addr_res = nullptr; const int res = ::getaddrinfo(hostname.data(), port.data(), &hints, &addr_res); this->resolved = true; if (res != 0) { this->error_msg = gai_strerror(res); if (this->error_cb) this->error_cb(this->error_msg.data()); } else { this->addr.reset(addr_res); if (this->success_cb) this->success_cb(this->addr.get()); } } #endif // ifdef CARES_FOUND std::string addr_to_string(const struct addrinfo* rp) { char buf[INET6_ADDRSTRLEN]; if (rp->ai_family == AF_INET) return ::inet_ntop(rp->ai_family, &reinterpret_cast<sockaddr_in*>(rp->ai_addr)->sin_addr, buf, sizeof(buf)); else if (rp->ai_family == AF_INET6) return ::inet_ntop(rp->ai_family, &reinterpret_cast<sockaddr_in6*>(rp->ai_addr)->sin6_addr, buf, sizeof(buf)); return {}; }