diff options
| -rw-r--r-- | src/linux/tun.c | 156 | ||||
| -rw-r--r-- | src/tun.h | 32 | ||||
| -rw-r--r-- | src/tun_helper.h | 90 | ||||
| -rw-r--r-- | src/uanytun.c | 19 |
4 files changed, 294 insertions, 3 deletions
diff --git a/src/linux/tun.c b/src/linux/tun.c index 971f344..005f125 100644 --- a/src/linux/tun.c +++ b/src/linux/tun.c @@ -33,3 +33,159 @@ */ #include "tun.h" + +#include "tun_helper.h" + +#include <stdlib.h> +#include <sys/wait.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <arpa/inet.h> +#include <errno.h> +#include <net/if.h> +#include <linux/ip.h> +#include <linux/if_ether.h> +#include <linux/if_tun.h> +#define DEFAULT_DEVICE "/dev/net/tun" + +#include "log.h" + +void tun_init(tun_device_t** dev, const char* dev_name, const char* dev_type, const char* ifcfg_lp, const char* ifcfg_rnmp) +{ + if(!dev) return; + + *dev = malloc(sizeof(tun_device_t)); + if(!*dev) return; + + tun_conf(*dev, dev_name, dev_type, ifcfg_lp, ifcfg_rnmp, 1400); + + (*dev)->fd_ = open(DEFAULT_DEVICE, O_RDWR); + if((*dev)->fd_ < 0) { + log_printf(ERR, "can't open device file (%s): %m", DEFAULT_DEVICE); + free(*dev); + *dev = NULL; + return; + } + + struct ifreq ifr; + memset(&ifr, 0, sizeof(ifr)); + + if((*dev)->type_ == TYPE_TUN) { + ifr.ifr_flags = IFF_TUN; + (*dev)->with_pi_ = 1; + } + else if((*dev)->type_ == TYPE_TAP) { + ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + (*dev)->with_pi_ = 0; + } + else { + log_printf(ERR, "unable to recognize type of device (tun or tap)"); + free(*dev); + *dev = NULL; + return; + } + + if(dev_name) + strncpy(ifr.ifr_name, dev_name, IFNAMSIZ); + + if(!ioctl((*dev)->fd_, TUNSETIFF, &ifr)) { + (*dev)->actual_name_ = strdup(ifr.ifr_name); + } else if(!ioctl((*dev)->fd_, (('T' << 8) | 202), &ifr)) { + (*dev)->actual_name_ = strdup(ifr.ifr_name); + } else { + log_printf(ERR, "tun/tap device ioctl failed: %m"); + free(*dev); + *dev = NULL; + return; + } + + if(ifcfg_lp && ifcfg_rnmp) + tun_do_ifconfig(*dev); +} + +void tun_init_post(tun_device_t* dev) +{ +// nothing yet +} + +void tun_close(tun_device_t** dev) +{ + if(!dev || !(*dev)) + return; + + if((*dev)->fd_ > 0) + close((*dev)->fd_); + + free(*dev); + *dev = NULL; +} + +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]; + struct tun_pi tpi; + + iov[0].iov_base = &tpi; + iov[0].iov_len = sizeof(tpi); + iov[1].iov_base = buf; + iov[1].iov_len = len; + return(tun_fix_return(readv(dev->fd_, iov, 2), sizeof(tpi))); + } + 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(dev->with_pi_) + { + struct iovec iov[2]; + struct tun_pi tpi; + struct iphdr *hdr = (struct iphdr *)buf; + + tpi.flags = 0; + if(hdr->version == 4) + tpi.proto = htons(ETH_P_IP); + else + tpi.proto = htons(ETH_P_IPV6); + + iov[0].iov_base = &tpi; + iov[0].iov_len = sizeof(tpi); + iov[1].iov_base = buf; + iov[1].iov_len = len; + return(tun_fix_return(writev(dev->fd_, iov, 2), sizeof(tpi))); + } + else + return(write(dev->fd_, buf, len)); +} + +void tun_do_ifconfig(tun_device_t* dev) +{ + if(!dev) + return; + + char* command = NULL; + if(dev->type_ == TYPE_TUN) + asprintf(&command, "/sbin/ifconfig %s %s pointopoint %s mtu %d" , dev->actual_name_, dev->local_, dev->remote_netmask_, dev->mtu_); + else + asprintf(&command, "/sbin/ifconfig %s %s netmask %s mtu %d" , dev->actual_name_, dev->local_, dev->remote_netmask_, dev->mtu_); + + 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)); +} @@ -35,6 +35,38 @@ #ifndef _TUN_H_ #define _TUN_H_ +#include <stdlib.h> +typedef unsigned char u_int8_t; +typedef unsigned short int u_int16_t; +typedef unsigned int u_int32_t; + + +enum device_type_enum { TYPE_UNDEF, TYPE_TUN, TYPE_TAP }; +typedef enum device_type_enum device_type_t; + +struct tun_device_struct { + int fd_; + unsigned int with_pi_; + char* actual_name_; + device_type_t type_; + u_int16_t mtu_; + char* local_; + char* remote_netmask_; +}; +typedef struct tun_device_struct tun_device_t; + +void tun_init(tun_device_t** dev, const char* dev_name, const char* dev_type, const char* ifcfg_lp, const char* ifcfg_rnmp); +void tun_init_post(tun_device_t* dev); +void tun_do_ifconfig(tun_device_t* dev); +void tun_close(tun_device_t** dev); + +int tun_read(tun_device_t* dev, u_int8_t* buf, u_int32_t len); +int tun_write(tun_device_t* dev, u_int8_t* buf, u_int32_t len); + +// in tun_helper.h +void tun_conf(tun_device_t* dev, const char* dev_name, const char* dev_type, const char* ifcfg_lp, const char* ifcfg_rnmp, u_int16_t mtu); +int tun_fix_return(int ret, size_t pi_length); +const char* tun_get_type_string(tun_device_t* dev); #endif diff --git a/src/tun_helper.h b/src/tun_helper.h new file mode 100644 index 0000000..c403f28 --- /dev/null +++ b/src/tun_helper.h @@ -0,0 +1,90 @@ +/* + * 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 <equinox@anytun.org> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#ifndef _TUN_HELPER_H_ +#define _TUN_HELPER_H_ + +#include <string.h> + +void tun_conf(tun_device_t* dev, const char* dev_name, const char* dev_type, const char* ifcfg_lp, const char* ifcfg_rnmp, u_int16_t mtu) +{ + if(!dev) return; + + dev->mtu_ = mtu; + dev->type_ = TYPE_UNDEF; + if(dev_type) { + if(!strncmp(dev_type, "tun", 3)) + dev->type_ = TYPE_TUN; + else if (!strncmp(dev_type, "tap", 3)) + dev->type_ = TYPE_TAP; + } + else if(dev_name) { + if(!strncmp(dev_name, "tun", 3)) + dev->type_ = TYPE_TUN; + else if(!strncmp(dev_name, "tap", 3)) + dev->type_ = TYPE_TAP; + } + + if(ifcfg_lp) + dev->local_ = strdup(ifcfg_lp); + if(ifcfg_rnmp) + dev->remote_netmask_ = strdup(ifcfg_rnmp); +} + + +int tun_fix_return(int ret, size_t pi_length) +{ + if(ret < 0) + return ret; + + return ((size_t)ret > pi_length ? (ret - pi_length) : 0); +} + +const char* tun_get_type_string(tun_device_t* dev) +{ + if(!dev || dev->fd_ < 0) + return ""; + + switch(dev->type_) + { + case TYPE_UNDEF: return "undef"; break; + case TYPE_TUN: return "tun"; break; + case TYPE_TAP: return "tap"; break; + } + return ""; +} + + + +#endif diff --git a/src/uanytun.c b/src/uanytun.c index 162ad5d..82085b4 100644 --- a/src/uanytun.c +++ b/src/uanytun.c @@ -47,11 +47,24 @@ int main(int argc, char* argv[]) signal_init(); // chrootAndDrop("/var/run/", "nobody"); - daemonize(); - log_printf(INFO, "running in background now"); +// daemonize(); +// log_printf(INFO, "running in background now"); + + tun_device_t* dev; + tun_init(&dev, "tun0", "tun", "192.168.23.1", "192.168.23.2"); + if(!dev) { + log_printf(ERR, "error on tun_init"); + exit -1; + } + log_printf(INFO, "entering main loop"); - while(1) sleep(1); + u_int8_t buf[1600]; + int len = 0; + while(1) { + len = tun_read(dev, buf, 1600); + printf("read %d bytes from device\n", len); + } } |