#include "route.hpp" #ifdef __linux__ #include #include #include #include #include #ifndef ANDROID #include #include #endif #include "net.hpp" #include #include #endif #ifdef __APPLE__ #include "net.hpp" #include #endif #ifdef _WIN32 #include #include #include #include #include #include #include #include #include "net_int.hpp" #include "ip.hpp" #endif #include #include #include namespace llarp::net { #ifndef __linux__ void Execute(std::string cmd) { LogInfo(cmd); system(cmd.c_str()); } #endif #ifdef __linux__ #ifndef ANDROID enum class GatewayMode { eFirstHop, eLowerDefault, eUpperDefault }; struct NLSocket { NLSocket() : fd(socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) { if (fd == -1) throw std::runtime_error("failed to make netlink socket"); } ~NLSocket() { if (fd != -1) close(fd); } const int fd; }; /* Helper structure for ip address data and attributes */ typedef struct { unsigned char family; unsigned char bitlen; unsigned char data[sizeof(struct in6_addr)]; } _inet_addr; /* */ #define NLMSG_TAIL(nmsg) ((struct rtattr*)(((intptr_t)(nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len))) /* Add new data to rtattr */ int rtattr_add(struct nlmsghdr* n, unsigned int maxlen, int type, const void* data, int alen) { int len = RTA_LENGTH(alen); struct rtattr* rta; if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) { fprintf(stderr, "rtattr_add error: message exceeded bound of %d\n", maxlen); return -1; } rta = NLMSG_TAIL(n); rta->rta_type = type; rta->rta_len = len; if (alen) { memcpy(RTA_DATA(rta), data, alen); } n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); return 0; } int do_route( int sock, int cmd, int flags, const _inet_addr* dst, const _inet_addr* gw, GatewayMode mode, int if_idx) { struct { struct nlmsghdr n; struct rtmsg r; char buf[4096]; } nl_request{}; /* Initialize request structure */ nl_request.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); nl_request.n.nlmsg_flags = NLM_F_REQUEST | flags; nl_request.n.nlmsg_type = cmd; nl_request.n.nlmsg_pid = getpid(); nl_request.r.rtm_family = dst->family; nl_request.r.rtm_table = RT_TABLE_MAIN; if (if_idx) { nl_request.r.rtm_scope = RT_SCOPE_LINK; } else { nl_request.r.rtm_scope = RT_SCOPE_NOWHERE; } /* Set additional flags if NOT deleting route */ if (cmd != RTM_DELROUTE) { nl_request.r.rtm_protocol = RTPROT_BOOT; nl_request.r.rtm_type = RTN_UNICAST; } nl_request.r.rtm_family = dst->family; nl_request.r.rtm_dst_len = dst->bitlen; nl_request.r.rtm_scope = 0; /* Set gateway */ if (gw->bitlen != 0 and dst->family == AF_INET) { rtattr_add(&nl_request.n, sizeof(nl_request), RTA_GATEWAY, &gw->data, gw->bitlen / 8); } nl_request.r.rtm_family = gw->family; if (mode == GatewayMode::eFirstHop) { rtattr_add( &nl_request.n, sizeof(nl_request), /*RTA_NEWDST*/ RTA_DST, &dst->data, dst->bitlen / 8); /* Set interface */ rtattr_add(&nl_request.n, sizeof(nl_request), RTA_OIF, &if_idx, sizeof(int)); } if (mode == GatewayMode::eUpperDefault) { if (dst->family == AF_INET) { rtattr_add( &nl_request.n, sizeof(nl_request), /*RTA_NEWDST*/ RTA_DST, &dst->data, sizeof(uint32_t)); } else { rtattr_add(&nl_request.n, sizeof(nl_request), RTA_OIF, &if_idx, sizeof(int)); rtattr_add( &nl_request.n, sizeof(nl_request), /*RTA_NEWDST*/ RTA_DST, &dst->data, sizeof(in6_addr)); } } /* Send message to the netlink */ return send(sock, &nl_request, sizeof(nl_request), 0); } int read_addr(const char* addr, _inet_addr* res, int bitlen = 32) { if (strchr(addr, ':')) { res->family = AF_INET6; res->bitlen = bitlen; } else { res->family = AF_INET; res->bitlen = bitlen; } return inet_pton(res->family, addr, res->data); } #endif #endif #ifdef _WIN32 std::wstring get_win_sys_path() { wchar_t win_sys_path[MAX_PATH] = {0}; const wchar_t* default_sys_path = L"C:\\Windows\\system32"; if (!GetSystemDirectoryW(win_sys_path, _countof(win_sys_path))) { wcsncpy(win_sys_path, default_sys_path, _countof(win_sys_path)); win_sys_path[_countof(win_sys_path) - 1] = L'\0'; } return win_sys_path; } std::string RouteCommand() { std::wstring wcmd = get_win_sys_path() + L"\\route.exe"; using convert_type = std::codecvt_utf8; std::wstring_convert converter; return converter.to_bytes(wcmd); } std::string NetshCommand() { std::wstring wcmd = get_win_sys_path() + L"\\netsh.exe"; using convert_type = std::codecvt_utf8; std::wstring_convert converter; return converter.to_bytes(wcmd); } template void ForEachWIN32Interface(Visit visit) { #define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x)) #define FREE(x) HeapFree(GetProcessHeap(), 0, (x)) MIB_IPFORWARDTABLE* pIpForwardTable; DWORD dwSize = 0; DWORD dwRetVal = 0; pIpForwardTable = (MIB_IPFORWARDTABLE*)MALLOC(sizeof(MIB_IPFORWARDTABLE)); if (pIpForwardTable == nullptr) return; if (GetIpForwardTable(pIpForwardTable, &dwSize, 0) == ERROR_INSUFFICIENT_BUFFER) { FREE(pIpForwardTable); pIpForwardTable = (MIB_IPFORWARDTABLE*)MALLOC(dwSize); if (pIpForwardTable == nullptr) { return; } } if ((dwRetVal = GetIpForwardTable(pIpForwardTable, &dwSize, 0)) == NO_ERROR) { for (int i = 0; i < (int)pIpForwardTable->dwNumEntries; i++) { visit(&pIpForwardTable->table[i]); } } FREE(pIpForwardTable); #undef MALLOC #undef FREE } std::optional GetInterfaceIndex(huint32_t ip) { std::optional ret = std::nullopt; ForEachWIN32Interface([&ret, n = ToNet(ip)](auto* iface) { if (ret.has_value()) return; if (iface->dwForwardNextHop == n.n) { ret = iface->dwForwardIfIndex; } }); return ret; } #endif void AddRoute(std::string ip, std::string gateway) { LogInfo("Add route: ", ip, " via ", gateway); #ifdef __linux__ #ifndef ANDROID NLSocket sock; int if_idx = 0; _inet_addr to_addr{}; _inet_addr gw_addr{}; int nl_cmd = RTM_NEWROUTE; int nl_flags = NLM_F_CREATE | NLM_F_EXCL; read_addr(gateway.c_str(), &gw_addr); read_addr(ip.c_str(), &to_addr); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eFirstHop, if_idx); #endif #else std::stringstream ss; #if _WIN32 ss << RouteCommand() << " ADD " << ip << " MASK 255.255.255.255 " << gateway << " METRIC 2"; #elif __APPLE__ ss << "/sbin/route -n add -host " << ip << " " << gateway; #else #error unsupported platform #endif Execute(ss.str()); #endif } void DelRoute(std::string ip, std::string gateway) { LogInfo("Delete route: ", ip, " via ", gateway); #ifdef __linux__ #ifndef ANDROID NLSocket sock; int if_idx = 0; _inet_addr to_addr{}; _inet_addr gw_addr{}; int nl_cmd = RTM_DELROUTE; int nl_flags = 0; read_addr(gateway.c_str(), &gw_addr); read_addr(ip.c_str(), &to_addr); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eFirstHop, if_idx); #endif #else std::stringstream ss; #if _WIN32 ss << RouteCommand() << " DELETE " << ip << " MASK 255.255.255.255 " << gateway << " METRIC 2"; #elif __APPLE__ ss << "/sbin/route -n delete -host " << ip << " " << gateway; #else #error unsupported platform #endif Execute(ss.str()); #endif } void AddDefaultRouteViaInterface(std::string ifname) { LogInfo("Add default route via ", ifname); #ifdef __linux__ #ifndef ANDROID NLSocket sock; int if_idx = if_nametoindex(ifname.c_str()); _inet_addr to_addr{}; _inet_addr gw_addr{}; const auto maybe = GetInterfaceAddr(ifname); if (not maybe.has_value()) throw std::runtime_error("we dont have our own net interface?"); int nl_cmd = RTM_NEWROUTE; int nl_flags = NLM_F_CREATE | NLM_F_EXCL; const auto host = maybe->asIPv4().ToString(); read_addr(host.c_str(), &gw_addr); read_addr("0.0.0.0", &to_addr, 1); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eLowerDefault, if_idx); read_addr("128.0.0.0", &to_addr, 1); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); const auto maybeInt = GetInterfaceIPv6Address(ifname); if (maybeInt.has_value()) { const auto host = maybeInt->ToString(); LogInfo("add v6 route via ", host); read_addr(host.c_str(), &gw_addr, 128); read_addr("::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("4000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("8000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("c000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); } #endif #elif _WIN32 // poke hole for loopback bacause god is dead on windows Execute(RouteCommand() + " ADD 127.0.0.0 MASK 255.0.0.0 0.0.0.0"); huint32_t ip{}; ip.FromString(ifname); const auto ipv6 = net::ExpandV4Lan(ip); Execute(RouteCommand() + " ADD ::/2 " + ipv6.ToString()); Execute(RouteCommand() + " ADD 4000::/2 " + ipv6.ToString()); Execute(RouteCommand() + " ADD 8000::/2 " + ipv6.ToString()); Execute(RouteCommand() + " ADD c000::/2 " + ipv6.ToString()); ifname.back()++; Execute(RouteCommand() + " ADD 0.0.0.0 MASK 128.0.0.0 " + ifname); Execute(RouteCommand() + " ADD 128.0.0.0 MASK 128.0.0.0 " + ifname); #elif __APPLE__ Execute("/sbin/route -n add -cloning -net 0.0.0.0 -netmask 128.0.0.0 -interface " + ifname); Execute("/sbin/route -n add -cloning -net 128.0.0.0 -netmask 128.0.0.0 -interface " + ifname); Execute("/sbin/route -n add -inet6 -net ::/2 -interface " + ifname); Execute("/sbin/route -n add -inet6 -net 4000::/2 -interface " + ifname); Execute("/sbin/route -n add -inet6 -net 8000::/2 -interface " + ifname); Execute("/sbin/route -n add -inet6 -net c000::/2 -interface " + ifname); #else #error unsupported platform #endif } void DelDefaultRouteViaInterface(std::string ifname) { LogInfo("Remove default route via ", ifname); #ifdef __linux__ #ifndef ANDROID NLSocket sock; int if_idx = if_nametoindex(ifname.c_str()); _inet_addr to_addr{}; _inet_addr gw_addr{}; const auto maybe = GetInterfaceAddr(ifname); if (not maybe.has_value()) throw std::runtime_error("we dont have our own net interface?"); int nl_cmd = RTM_DELROUTE; int nl_flags = 0; const auto host = maybe->asIPv4().ToString(); read_addr(host.c_str(), &gw_addr); read_addr("0.0.0.0", &to_addr, 1); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eLowerDefault, if_idx); read_addr("128.0.0.0", &to_addr, 1); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); const auto maybeInt = GetInterfaceIPv6Address(ifname); if (maybeInt.has_value()) { const auto host = maybeInt->ToString(); LogInfo("del v6 route via ", host); read_addr(host.c_str(), &gw_addr, 128); read_addr("::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("4000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("8000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); read_addr("c000::", &to_addr, 2); do_route(sock.fd, nl_cmd, nl_flags, &to_addr, &gw_addr, GatewayMode::eUpperDefault, if_idx); } #endif #elif _WIN32 huint32_t ip{}; ip.FromString(ifname); const auto ipv6 = net::ExpandV4Lan(ip); Execute(RouteCommand() + " DELETE ::/2 " + ipv6.ToString()); Execute(RouteCommand() + " DELETE 4000::/2 " + ipv6.ToString()); Execute(RouteCommand() + " DELETE 8000::/2 " + ipv6.ToString()); Execute(RouteCommand() + " DELETE c000::/2 " + ipv6.ToString()); ifname.back()++; Execute(RouteCommand() + " DELETE 0.0.0.0 MASK 128.0.0.0 " + ifname); Execute(RouteCommand() + " DELETE 128.0.0.0 MASK 128.0.0.0 " + ifname); Execute(RouteCommand() + " DELETE 127.0.0.0 MASK 255.0.0.0 0.0.0.0"); #elif __APPLE__ Execute("/sbin/route -n delete -cloning -net 0.0.0.0 -netmask 128.0.0.0 -interface " + ifname); Execute( "/sbin/route -n delete -cloning -net 128.0.0.0 -netmask 128.0.0.0 -interface " + ifname); Execute("/sbin/route -n delete -inet6 -net ::/2 -interface " + ifname); Execute("/sbin/route -n delete -inet6 -net 4000::/2 -interface " + ifname); Execute("/sbin/route -n delete -inet6 -net 8000::/2 -interface " + ifname); Execute("/sbin/route -n delete -inet6 -net c000::/2 -interface " + ifname); #else #error unsupported platform #endif } std::vector GetGatewaysNotOnInterface(std::string ifname) { std::vector gateways; #ifdef __linux__ #ifdef ANDROID #else std::ifstream inf("/proc/net/route"); for (std::string line; std::getline(inf, line);) { const auto parts = split(line, '\t'); if (parts[1].find_first_not_of('0') == std::string::npos and parts[0] != ifname) { const auto& ip = parts[2]; if ((ip.size() == sizeof(uint32_t) * 2) and oxenmq::is_hex(ip)) { huint32_t x{}; oxenmq::from_hex(ip.begin(), ip.end(), reinterpret_cast(&x.h)); gateways.emplace_back(x.ToString()); } } } #endif return gateways; #elif _WIN32 ForEachWIN32Interface([&](auto w32interface) { struct in_addr gateway, interface_addr; gateway.S_un.S_addr = (u_long)w32interface->dwForwardDest; interface_addr.S_un.S_addr = (u_long)w32interface->dwForwardNextHop; std::string interface_name{inet_ntoa(interface_addr)}; if ((!gateway.S_un.S_addr) and interface_name != ifname) { llarp::LogTrace( "Win32 find gateway: Adding gateway (", interface_name, ") to list of gateways."); gateways.push_back(std::move(interface_name)); } }); return gateways; #elif __APPLE__ LogDebug("get gateways not on ", ifname); // mac os is so godawful man FILE* p = popen("/usr/sbin/netstat -rn -f inet", "r"); if (p == nullptr) { return gateways; } char* line = nullptr; size_t len = 0; ssize_t read = 0; while ((read = getline(&line, &len, p)) != -1) { const std::string line_str(line, len); const auto parts = llarp::split_any(line_str, " "sv, true); if (parts[0] == "default" and parts[3] != ifname) { gateways.emplace_back(parts[1]); } } pclose(p); return gateways; #else #error unsupported platform #endif } } // namespace llarp::net