/* * ľAnytun * * ľAnytun is a tiny implementation of SATP. Unlike Anytun which is a full * featured implementation ľAnytun has no support for multiple connections * or synchronisation. It is a small single threaded implementation intended * to act as a client on small platforms. * The secure anycast tunneling protocol (satp) defines a protocol used * for communication between any combination of unicast and anycast * tunnel endpoints. It has less protocol overhead than IPSec in Tunnel * mode and allows tunneling of every ETHER TYPE protocol (e.g. * ethernet, ip, arp ...). satp directly includes cryptography and * message authentication based on the methodes used by SRTP. It is * intended to deliver a generic, scaleable and secure solution for * tunneling and relaying of packets of any protocol. * * * Copyright (C) 2007-2008 Christian Pointner * * This file is part of ľAnytun. * * ľAnytun is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License version 3 as * published by the Free Software Foundation. * * ľAnytun is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ľAnytun. If not, see . */ #include "datatypes.h" #include "tun.h" #include "tun_helper.h" #include "log.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEVICE_FILE_MAX 255 int tun_init(tun_device_t* dev, const char* dev_name, const char* dev_type, const char* ifcfg_addr, u_int16_t ifcfg_prefix) { if(!dev) return; tun_conf(dev, dev_name, dev_type, ifcfg_addr, ifcfg_prefix, 1400); dev->actual_name_ = NULL; char* device_file = NULL; char* actual_name_start = NULL; int dynamic = 1; if(dev_name) { asprintf(&device_file, "/dev/%s", dev_name); dynamic = 0; } else if(dev->type_ == TYPE_TUN) { asprintf(&device_file, "/dev/tun"); actual_name_start = "tun"; } else if(dev->type_ == TYPE_TAP) { asprintf(&device_file, "/dev/tap"); actual_name_start = "tap"; } else { log_printf(ERR, "unable to recognize type of device (tun or tap)"); tun_close(dev); return -1; } if(!device_file) { log_printf(ERR, "can't open device file: memory error"); tun_close(dev); return -2; } u_int32_t dev_id=0; if(dynamic) { for(; dev_id <= DEVICE_FILE_MAX; ++dev_id) { char* device_file_tmp = NULL; asprintf(&device_file_tmp, "%s%d", device_file, dev_id); if(!device_file_tmp) { log_printf(ERR, "can't open device file: memory error"); free(device_file); tun_close(dev); return -2; } dev->fd_ = open(device_file_tmp, O_RDWR); free(device_file_tmp); if(dev->fd_ >= 0) break; } } else dev->fd_ = open(device_file, O_RDWR); free(device_file); if(dev->fd_ < 0) { if(dynamic) log_printf(ERR, "can't open device file dynamically: no unused node left"); else log_printf(ERR, "can't open device file (%s): %m", device_file); tun_close(dev); return -1; } if(dynamic) asprintf(&(dev->actual_name_), "%s%d", actual_name_start, dev_id); else dev->actual_name_ = strdup(dev_name); if(!dev->actual_name_) { log_printf(ERR, "can't open device file: memory error"); tun_close(dev); return -2; } int ret = tun_init_post(dev); if(ret) return ret; if(ifcfg_addr) tun_do_ifconfig(dev); return 0; } #if defined(__GNUC__) && defined(__OpenBSD__) int tun_init_post(tun_device_t* dev) { if(!dev) return -1; dev->with_pi_ = 1; if(dev->type_ == TYPE_TAP) dev->with_pi_ = 0; struct tuninfo ti; if (ioctl(dev->fd_, TUNGIFINFO, &ti) < 0) { log_printf(ERR, "can't enable multicast for interface"); return -1; } ti.flags |= IFF_MULTICAST; if (ioctl(dev->fd_, TUNSIFINFO, &ti) < 0) { log_printf(ERR, "can't enable multicast for interface"); return -1; } return 0; } #elif defined(__GNUC__) && defined(__FreeBSD__) int tun_init_post(tun_device_t* dev) { if(!dev) return -1; dev->with_pi_ = 1; if(dev->type_ == TYPE_TAP) dev->with_pi_ = 0; int arg = 0; ioctl(dev->fd_, TUNSLMODE, &arg); arg = 1; ioctl(dev->fd_, TUNSIFHEAD, &arg); return 0; } #elif defined(__GNUC__) && defined(__NetBSD__) int tun_init_post(tun_device_t* dev) { if(!dev) return -1; dev->with_pi_ = 0; int arg = IFF_POINTOPOINT|IFF_MULTICAST; ioctl(dev->fd_, TUNSIFMODE, &arg); arg = 0; ioctl(dev->fd_, TUNSLMODE, &arg); return 0; } #else #error This Device works just for OpenBSD, FreeBSD or NetBSD #endif void tun_close(tun_device_t* dev) { if(!dev) return; if(dev->fd_ > 0) close(dev->fd_); if(dev->actual_name_) free(dev->actual_name_); if(dev->net_addr_) free(dev->net_addr_); } int tun_read(tun_device_t* dev, u_int8_t* buf, u_int32_t len) { if(!dev || dev->fd_ < 0) return -1; if(dev->with_pi_) { struct iovec iov[2]; u_int32_t type; iov[0].iov_base = &type; iov[0].iov_len = sizeof(type); iov[1].iov_base = buf; iov[1].iov_len = len; return(tun_fix_return(readv(dev->fd_, iov, 2), sizeof(type))); } else return(read(dev->fd_, buf, len)); } int tun_write(tun_device_t* dev, u_int8_t* buf, u_int32_t len) { if(!dev || dev->fd_ < 0) return -1; if(!buf) return 0; if(dev->with_pi_) { struct iovec iov[2]; u_int32_t type; struct ip *hdr = (struct ip*)buf; type = 0; if(hdr->ip_v == 4) type = htonl(AF_INET); else type = htonl(AF_INET6); iov[0].iov_base = &type; iov[0].iov_len = sizeof(type); iov[1].iov_base = buf; iov[1].iov_len = len; return(tun_fix_return(writev(dev->fd_, iov, 2), sizeof(type))); } else return(write(dev->fd_, buf, len)); } void tun_do_ifconfig(tun_device_t* dev) { if(!dev || !dev->actual_name_ || !dev->net_addr_) return; /* char* command = NULL; */ /* char* netmask; */ /* char* end; */ /* if(dev->type_ == TYPE_TAP) { */ /* netmask = "netmask "; */ /* #if defined(__GNUC__) && defined(__OpenBSD__) */ /* end = " link0"; */ /* #elif defined(__GNUC__) && defined(__FreeBSD__) */ /* end = " up"; */ /* #elif defined(__GNUC__) && defined(__NetBSD__) */ /* end = ""; */ /* #else */ /* #error This Device works just for OpenBSD, FreeBSD or NetBSD */ /* #endif */ /* } */ /* else { */ /* netmask = ""; */ /* end = " netmask 255.255.255.255 up"; */ /* } */ /* asprintf(&command, "/sbin/ifconfig %s %s %s%s mtu %d%s", dev->actual_name_, dev->local_ , netmask, */ /* dev->remote_netmask_, dev->mtu_, end); */ /* if(!command) { */ /* log_printf(ERR, "Execution of ifconfig failed"); */ /* return; */ /* } */ /* int result = system(command); */ /* if(result == -1) */ /* log_printf(ERR, "Execution of ifconfig failed"); */ /* else */ /* log_printf(NOTICE, "ifconfig returned %d", WEXITSTATUS(result)); */ /* free(command); */ }