// SPDX-License-Identifier: AGPL-1.0-only // Copyright (C) 2018 Ludvig Strigeus . All Rights Reserved. #include "network_bsd_common.h" #include "tunsafe_endian.h" #include "util.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(OS_MACOSX) #include #include #include #include #include #include #elif defined(OS_FREEBSD) #include #include #elif defined(OS_LINUX) #include #include #include #include #endif void SetThreadName(const char *name) { #if defined(OS_LINUX) prctl(PR_SET_NAME, name, 0, 0, 0); #endif // defined(OS_LINUX) } #if defined(OS_MACOSX) || defined(OS_FREEBSD) struct MyRouteMsg { struct rt_msghdr hdr; uint32 pad; struct sockaddr_in target; struct sockaddr_in netmask; }; struct MyRouteReply { struct rt_msghdr hdr; uint8 buf[512]; }; // Zero gets rounded up #if defined(OS_MACOSX) #define RTMSG_ROUNDUP(a) ((a) ? ((((a) - 1) | (sizeof(uint32_t) - 1)) + 1) : sizeof(uint32_t)) #else #define RTMSG_ROUNDUP(a) ((a) ? ((((a) - 1) | (sizeof(long) - 1)) + 1) : sizeof(long)) #endif static bool GetDefaultRoute(char *iface, size_t iface_size, uint32 *gw_addr) { int fd, pid, len; union { MyRouteMsg rt; MyRouteReply rep; }; fd = socket(PF_ROUTE, SOCK_RAW, AF_INET); if (fd < 0) return false; memset(&rt, 0, sizeof(rt)); rt.hdr.rtm_type = RTM_GET; rt.hdr.rtm_flags = RTF_UP | RTF_GATEWAY; rt.hdr.rtm_version = RTM_VERSION; rt.hdr.rtm_seq = 0; rt.hdr.rtm_addrs = RTA_DST | RTA_NETMASK | RTA_IFP; rt.target.sin_family = AF_INET; rt.netmask.sin_family = AF_INET; rt.target.sin_len = sizeof(struct sockaddr_in); rt.netmask.sin_len = sizeof(struct sockaddr_in); rt.hdr.rtm_msglen = sizeof(rt); if (write(fd, (char*)&rt, sizeof(rt)) != sizeof(rt)) { RERROR("PF_ROUTE write failed."); close(fd); return false; } pid = getpid(); do { len = read(fd, (char *)&rep, sizeof(rep)); if (len <= 0) { RERROR("PF_ROUTE read failed."); close(fd); return false; } } while (rep.hdr.rtm_seq != 0 || rep.hdr.rtm_pid != pid); close(fd); const struct sockaddr_dl *ifp = NULL; const struct sockaddr_in *gw = NULL; uint8 *pos = rep.buf; for (int i = 1; i && i < rep.hdr.rtm_addrs; i <<= 1) { if (rep.hdr.rtm_addrs & i) { if (1 > rep.buf + 512 - pos) break; // invalid size_t len = RTMSG_ROUNDUP(((struct sockaddr*)pos)->sa_len); if (len > rep.buf + 512 - pos) break; // invalid // RINFO("rtm %d %d", i, ((struct sockaddr*)pos)->sa_len); if (i == RTA_IFP && ((struct sockaddr*)pos)->sa_len >= sizeof(struct sockaddr_dl)) { ifp = (struct sockaddr_dl *)pos; } else if (i == RTA_GATEWAY && ((struct sockaddr*)pos)->sa_len >= sizeof(struct sockaddr_in)) { gw = (struct sockaddr_in *)pos; } pos += len; } } if (ifp && ifp->sdl_nlen && ifp->sdl_nlen < iface_size) { iface[ifp->sdl_nlen] = 0; memcpy(iface, ifp->sdl_data, ifp->sdl_nlen); if (gw && gw->sin_family == AF_INET) { *gw_addr = ReadBE32(&gw->sin_addr); return true; } } // RINFO("Read %d %d %d", len, rep.hdr.rtm_addrs, (int)sizeof(struct rt_msghdr )); return false; } #endif // defined(OS_MACOSX) || defined(OS_FREEBSD) #if defined(OS_LINUX) struct LinuxParsedRoute { int has; struct in_addr dst, gateway; char ifname[IF_NAMESIZE]; }; static bool ParseLinuxRoutes(struct nlmsghdr *nl, struct LinuxParsedRoute *result) { struct rtmsg *rt = (struct rtmsg *)NLMSG_DATA(nl); if (rt->rtm_family != AF_INET || rt->rtm_table != RT_TABLE_MAIN) return false; struct rtattr *attr = (struct rtattr *)RTM_RTA(rt); int len = RTM_PAYLOAD(nl); int has = 0; for(; RTA_OK(attr, len); attr = RTA_NEXT(attr, len)) { switch(attr->rta_type) { case RTA_OIF: has |= 1; if_indextoname(*(int *)RTA_DATA(attr), result->ifname); break; case RTA_GATEWAY: has |= 2; memcpy(&result->gateway, RTA_DATA(attr), sizeof(result->gateway)); break; case RTA_DST: has |= 4; memcpy(&result->dst, RTA_DATA(attr), sizeof(result->dst)); break; } } result->has = has; return true; } static bool GetDefaultRoute(char *iface, size_t iface_size, uint32 *gw_addr) { enum {BUFSIZE = 8192}; struct nlmsghdr *nl; struct rtmsg *rt; struct LinuxParsedRoute parsed_route; char buffer[BUFSIZE]; int fd, len, pid = getpid(); bool result = false; if ((fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0) return false; size_t msg_size = NLMSG_SPACE(sizeof(struct rtmsg)); memset(buffer, 0, msg_size); nl = (struct nlmsghdr *)buffer; nl->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); nl->nlmsg_type = RTM_GETROUTE; nl->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST; nl->nlmsg_seq = 1; nl->nlmsg_pid = pid; rt = (struct rtmsg *)NLMSG_DATA(nl); rt->rtm_family = AF_INET; rt->rtm_table = RT_TABLE_MAIN; if (send(fd, nl, msg_size, 0) != msg_size) { RERROR("write to route socket failed"); goto done; } do { if ((len = recv(fd, buffer, BUFSIZE, 0)) < 0) { RERROR("read from route socket failed"); goto done; } for (nl = (struct nlmsghdr *)buffer; NLMSG_OK(nl, len); nl = NLMSG_NEXT(nl, len)) { if (nl->nlmsg_seq != 1 || nl->nlmsg_pid != pid) continue; if (nl->nlmsg_type == NLMSG_DONE) goto done; if (nl->nlmsg_type == NLMSG_ERROR) { RERROR("Error in recieved packet"); goto done; } if (ParseLinuxRoutes(nl, &parsed_route) && (parsed_route.has & (1+2+4)) == (1+2)) { size_t l = strlen(parsed_route.ifname); if (l < iface_size) { *gw_addr = ReadBE32(&parsed_route.gateway); memcpy(iface, parsed_route.ifname, l + 1); result = true; } } } } while ((nl->nlmsg_flags & NLM_F_MULTI) != 0); done: close(fd); return result; } #endif // defined(OS_LINUX) #if defined(OS_MACOSX) static mach_timebase_info_data_t timebase = { 0, 0 }; static uint64_t initclock; void InitOsxGetMilliseconds() { if (mach_timebase_info(&timebase) != 0) abort(); initclock = mach_absolute_time(); timebase.denom *= 1000000; } uint64 OsGetMilliseconds() { uint64_t clock = mach_absolute_time() - initclock; return clock * (uint64_t)timebase.numer / (uint64_t)timebase.denom; } #else // defined(OS_MACOSX) uint64 OsGetMilliseconds() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) { //error fprintf(stderr, "clock_gettime failed\n"); exit(1); } return (uint64)ts.tv_sec * 1000 + (ts.tv_nsec / 1000000); } #endif void OsGetTimestampTAI64N(uint8 dst[12]) { struct timeval tv; gettimeofday(&tv, NULL); uint64 secs_since_epoch = tv.tv_sec + 0x400000000000000a; uint32 nanos = tv.tv_usec * 1000; WriteBE64(dst, secs_since_epoch); WriteBE32(dst + 8, nanos); } void OsGetRandomBytes(uint8 *data, size_t data_size) { int fd = open("/dev/urandom", O_RDONLY); int r = read(fd, data, data_size); if (r < 0) r = 0; close(fd); for (; r < data_size; r++) data[r] = rand() >> 6; } void OsInterruptibleSleep(int millis) { usleep((useconds_t)millis * 1000); } #if defined(OS_MACOSX) int open_tun(char *devname, size_t devname_size) { struct sockaddr_ctl sc; struct ctl_info ctlinfo = {0}; int fd; memcpy(ctlinfo.ctl_name, UTUN_CONTROL_NAME, sizeof(UTUN_CONTROL_NAME)); for(int i = 0; i < 256; i++) { fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL); if (fd < 0) { RERROR("socket(SYSPROTO_CONTROL) failed"); return -1; } if (ioctl(fd, CTLIOCGINFO, &ctlinfo) == -1) { RERROR("ioctl(CTLIOCGINFO) failed: %d", errno); close(fd); return -1; } sc.sc_id = ctlinfo.ctl_id; sc.sc_len = sizeof(sc); sc.sc_family = AF_SYSTEM; sc.ss_sysaddr = AF_SYS_CONTROL; sc.sc_unit = i + 1; if (connect(fd, (struct sockaddr *)&sc, sizeof(sc)) == 0) { socklen_t devname_size2 = devname_size; if (getsockopt(fd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, devname, &devname_size2)) { RERROR("getsockopt(UTUN_OPT_IFNAME) failed"); close(fd); return -1; } return fd; } close(fd); } return -1; } #elif defined(OS_FREEBSD) int open_tun(char *devname, size_t devname_size) { char buf[32]; int tun_fd; // First open an existing tun device for(int i = 0; i < 256; i++) { sprintf(buf, "/dev/tun%d", i); tun_fd = open(buf, O_RDWR); if (tun_fd >= 0) goto did_open; } tun_fd = open("/dev/tun", O_RDWR); if (tun_fd < 0) return tun_fd; did_open: if (!fdevname_r(tun_fd, devname, devname_size)) { RERROR("Unable to get name of tun device"); close(tun_fd); return -1; } int flags = IFF_POINTOPOINT | IFF_MULTICAST; if (ioctl(tun_fd, TUNSIFMODE, &flags) < 0) { RERROR("ioctl(TUNSIFMODE) failed"); close(tun_fd); return -1; } flags = 1; if (ioctl(tun_fd, TUNSIFHEAD, &flags) < 0) { RERROR("ioctl(TUNSIFHEAD) failed"); close(tun_fd); return -1; } return tun_fd; } #elif defined(OS_LINUX) int open_tun(char *devname, size_t devname_size) { int fd, err; struct ifreq ifr; fd = open("/dev/net/tun", O_RDWR); if (fd < 0) return fd; memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TUN | IFF_NO_PI; if ((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0) { close(fd); return err; } strcpy(devname, ifr.ifr_name); return fd; } #endif int open_udp(int listen_on_port) { int udp_fd = socket(AF_INET, SOCK_DGRAM, 0); if (udp_fd < 0) return udp_fd; sockaddr_in sin = {0}; sin.sin_family = AF_INET; sin.sin_port = htons(listen_on_port); if (bind(udp_fd, (struct sockaddr*)&sin, sizeof(sin)) != 0) { close(udp_fd); return -1; } return udp_fd; } TunsafeBackendBsd::TunsafeBackendBsd() : processor_(NULL) { } TunsafeBackendBsd::~TunsafeBackendBsd() { } static uint32 CidrToNetmaskV4(int cidr) { return cidr == 32 ? 0xffffffff : 0xffffffff << (32 - cidr); } static uint32 ComputeIpv4DefaultRoute(uint32 ip, uint32 netmask) { uint32 default_route_v4 = (ip & netmask) | 1; if (default_route_v4 == ip) default_route_v4++; return default_route_v4; } static void ComputeIpv6DefaultRoute(const uint8 *ipv6_address, uint8 ipv6_cidr, uint8 *default_route_v6) { memcpy(default_route_v6, ipv6_address, 16); // clear the last bits of the ipv6 address to match the cidr. size_t n = (ipv6_cidr + 7) >> 3; memset(&default_route_v6[n], 0, 16 - n); if (n == 0) return; // adjust the final byte default_route_v6[n - 1] &= ~(0xff >> (ipv6_cidr & 7)); // set the very last byte to something default_route_v6[15] |= 1; // ensure it doesn't collide if (memcmp(default_route_v6, ipv6_address, 16) == 0) default_route_v6[15] ^= 3; } void TunsafeBackendBsd::AddRoute(uint32 ip, uint32 cidr, uint32 gw) { uint32 ip_be, gw_be; WriteBE32(&ip_be, ip); WriteBE32(&gw_be, gw); AddRoute(AF_INET, &ip_be, cidr, &gw_be); } static void AddOrRemoveRoute(const RouteInfo &cd, bool remove) { char buf1[kSizeOfAddress], buf2[kSizeOfAddress]; print_ip_prefix(buf1, cd.family, cd.ip, cd.cidr); print_ip_prefix(buf2, cd.family, cd.gw, -1); #if defined(OS_LINUX) const char *cmd = remove ? "delete" : "add"; if (cd.family == AF_INET) { const char *net_or_host = (cd.cidr == 32) ? "-host" : "-net"; RunCommand("/sbin/route %s %s %s gw %s", cmd, net_or_host, buf1, buf2); } else { const char *net_or_host = (cd.cidr == 128) ? "-host" : "-net"; RunCommand("/sbin/route %s %s inet6 %s gw %s", cmd, net_or_host, buf1, buf2); } #elif defined(OS_MACOSX) || defined(OS_FREEBSD) const char *cmd = remove ? "delete" : "add"; if (cd.family == AF_INET) { RunCommand("/sbin/route -q %s %s %s", cmd, buf1, buf2); } else { RunCommand("/sbin/route -q %s -inet6 %s %s", cmd, buf1, buf2); } #endif } bool TunsafeBackendBsd::AddRoute(int family, const void *dest, int dest_prefix, const void *gateway) { RouteInfo c; c.family = family; size_t len = (family == AF_INET) ? 4 : 16; memcpy(c.ip, dest, len); memcpy(c.gw, gateway, len); c.cidr = dest_prefix; cleanup_commands_.push_back(c); AddOrRemoveRoute(c, false); return true; } void TunsafeBackendBsd::DelRoute(const RouteInfo &cd) { AddOrRemoveRoute(cd, true); } static bool IsIpv6AddressSet(const void *p) { return (ReadLE64(p) | ReadLE64((char*)p + 8)) != 0; } // Called to initialize tun bool TunsafeBackendBsd::Initialize(const TunConfig &&config, TunConfigOut *out) override { char def_iface[12]; char devname[16]; if (!RunPrePostCommand(config.pre_post_commands.pre_up)) { RERROR("Pre command failed!"); return false; } out->enable_neighbor_discovery_spoofing = false; if (!InitializeTun(devname)) return false; if (config.ipv6_cidr) RERROR("IPv6 not supported"); uint32 netmask = CidrToNetmaskV4(config.cidr); uint32 default_route_v4 = ComputeIpv4DefaultRoute(config.ip, netmask); RunCommand("/sbin/ifconfig %s %A mtu %d %A netmask %A up", devname, config.ip, config.mtu, config.ip, netmask); AddRoute(config.ip & netmask, config.cidr, config.ip); if (config.use_ipv4_default_route) { if (config.default_route_endpoint_v4) { uint32 gw; if (!GetDefaultRoute(def_iface, sizeof(def_iface), &gw)) { RERROR("Unable to determine default interface."); return false; } AddRoute(config.default_route_endpoint_v4, 32, gw); } AddRoute(0x00000000, 1, default_route_v4); AddRoute(0x80000000, 1, default_route_v4); } uint8 default_route_v6[16]; if (config.ipv6_cidr) { static const uint8 matchall_1_route[17] = {0x80, 0, 0, 0}; char buf[kSizeOfAddress]; ComputeIpv6DefaultRoute(config.ipv6_address, config.ipv6_cidr, default_route_v6); RunCommand("/sbin/ifconfig %s inet6 %s", devname, print_ip_prefix(buf, AF_INET6, config.ipv6_address, config.ipv6_cidr)); if (config.use_ipv6_default_route) { if (IsIpv6AddressSet(config.default_route_endpoint_v6)) { RERROR("default_route_endpoint_v6 not supported"); } AddRoute(AF_INET6, matchall_1_route + 1, 1, default_route_v6); AddRoute(AF_INET6, matchall_1_route + 0, 1, default_route_v6); } } // Add all the extra routes for (auto it = config.extra_routes.begin(); it != config.extra_routes.end(); ++it) { if (it->size == 32) { AddRoute(ReadBE32(it->addr), it->cidr, default_route_v4); } else if (it->size == 128 && config.ipv6_cidr) { AddRoute(AF_INET6, it->addr, it->cidr, default_route_v6); } } RunPrePostCommand(config.pre_post_commands.post_up); pre_down_ = std::move(config.pre_post_commands.pre_down); post_down_ = std::move(config.pre_post_commands.post_down); return true; } void TunsafeBackendBsd::CleanupRoutes() { RunPrePostCommand(pre_down_); for(auto it = cleanup_commands_.begin(); it != cleanup_commands_.end(); ++it) DelRoute(*it); cleanup_commands_.clear(); RunPrePostCommand(post_down_); pre_down_.clear(); post_down_.clear(); } static bool RunOneCommand(const std::string &cmd) { RINFO("Run: %s", cmd.c_str()); int exit_code = system(cmd.c_str()); if (exit_code) { RERROR("Run Failed (%d) : %s", exit_code, cmd.c_str()); return false; } return true; } bool TunsafeBackendBsd::RunPrePostCommand(const std::vector &vec) { bool success = true; for (auto it = vec.begin(); it != vec.end(); ++it) { success &= RunOneCommand(*it); } return success; } static TunsafeBackendBsd *g_tunsafe_backend_bsd; static void SigAlrm(int sig) { if (g_tunsafe_backend_bsd) g_tunsafe_backend_bsd->HandleSigAlrm(); } static void SigUsr1(int sig) { } static bool did_ctrlc; void SigInt(int sig) { if (did_ctrlc) exit(1); did_ctrlc = true; write(1, "Ctrl-C detected. Exiting. Press again to force quit.\n", sizeof("Ctrl-C detected. Exiting. Press again to force quit.\n")-1); if (g_tunsafe_backend_bsd) g_tunsafe_backend_bsd->HandleExit(); } void TunsafeBackendBsd::RunLoop() { assert(!g_tunsafe_backend_bsd); assert(processor_); g_tunsafe_backend_bsd = this; // We want an alarm signal every second. { struct sigaction act = {0}; act.sa_handler = SigAlrm; if (sigaction(SIGALRM, &act, NULL) < 0) { RERROR("Unable to install SIGALRM handler."); return; } } { struct sigaction act = {0}; act.sa_handler = SigInt; if (sigaction(SIGINT, &act, NULL) < 0) { RERROR("Unable to install SIGINT handler."); return; } } { struct sigaction act = {0}; act.sa_handler = SigUsr1; if (sigaction(SIGUSR1, &act, NULL) < 0) { RERROR("Unable to install SIGUSR1 handler."); return; } } #if defined(OS_LINUX) || defined(OS_FREEBSD) { struct itimerspec tv = {0}; struct sigevent sev; timer_t timer_id; tv.it_interval.tv_sec = 1; tv.it_value.tv_sec = 1; sev.sigev_notify = SIGEV_SIGNAL; sev.sigev_signo = SIGALRM; sev.sigev_value.sival_ptr = NULL; if (timer_create(CLOCK_MONOTONIC, &sev, &timer_id) < 0) { RERROR("timer_create failed"); return; } if (timer_settime(timer_id, 0, &tv, NULL) < 0) { RERROR("timer_settime failed"); return; } } #elif defined(OS_MACOSX) ualarm(1000000, 1000000); #endif RunLoopInner(); g_tunsafe_backend_bsd = NULL; } void InitCpuFeatures(); void Benchmark(); uint32 g_ui_ip; const char *print_ip(char buf[kSizeOfAddress], in_addr_t ip) { snprintf(buf, kSizeOfAddress, "%d.%d.%d.%d", (ip >> 24) & 0xff, (ip >> 16) & 0xff, (ip >> 8) & 0xff, (ip >> 0) & 0xff); return buf; } class MyProcessorDelegate : public ProcessorDelegate { public: virtual void OnConnected(in_addr_t my_ip) { if (my_ip != g_ui_ip) { if (my_ip) { char buf[kSizeOfAddress]; print_ip(buf, my_ip); RINFO("Connection established. IP %s", buf); } g_ui_ip = my_ip; } } virtual void OnDisconnected() { MyProcessorDelegate::OnConnected(0); } }; int main(int argc, char **argv) { bool exit_flag = false; InitCpuFeatures(); if (argc == 2 && strcmp(argv[1], "--benchmark") == 0) { Benchmark(); return 0; } fprintf(stderr, "%s\n", TUNSAFE_VERSION_STRING); if (argc < 2) { fprintf(stderr, "Syntax: tunsafe file.conf\n"); return 1; } #if defined(OS_MACOSX) InitOsxGetMilliseconds(); #endif SetThreadName("tunsafe-m"); MyProcessorDelegate my_procdel; TunsafeBackendBsd *socket_loop = CreateTunsafeBackendBsd(); WireguardProcessor wg(socket_loop, socket_loop, &my_procdel); socket_loop->SetProcessor(&wg); if (!ParseWireGuardConfigFile(&wg, argv[1], &exit_flag)) return 1; if (!wg.Start()) return 1; socket_loop->RunLoop(); socket_loop->CleanupRoutes(); delete socket_loop; return 0; }