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- /*
- device.c -- Interaction BSD tun/tap device
- Copyright (C) 2001-2005 Ivo Timmermans,
- 2001-2016 Guus Sliepen <guus@tinc-vpn.org>
- 2009 Grzegorz Dymarek <gregd72002@googlemail.com>
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program 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 this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
- #include "../system.h"
- #include "../conf.h"
- #include "../device.h"
- #include "../logger.h"
- #include "../net.h"
- #include "../route.h"
- #include "../utils.h"
- #include "../xalloc.h"
- #ifdef ENABLE_TUNEMU
- #include "tunemu.h"
- #endif
- #ifdef HAVE_NET_IF_UTUN_H
- #include <sys/sys_domain.h>
- #include <sys/kern_control.h>
- #include <net/if_utun.h>
- #endif
- #define DEFAULT_TUN_DEVICE "/dev/tun0"
- #define DEFAULT_TAP_DEVICE "/dev/tap0"
- typedef enum device_type {
- DEVICE_TYPE_TUN,
- DEVICE_TYPE_TUNIFHEAD,
- DEVICE_TYPE_TAP,
- #ifdef ENABLE_TUNEMU
- DEVICE_TYPE_TUNEMU,
- #endif
- DEVICE_TYPE_UTUN,
- } device_type_t;
- int device_fd = -1;
- char *device = NULL;
- char *iface = NULL;
- static const char *device_info = "OS X utun device";
- static uint64_t device_total_in = 0;
- static uint64_t device_total_out = 0;
- #if defined(ENABLE_TUNEMU)
- static device_type_t device_type = DEVICE_TYPE_TUNEMU;
- #elif defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD) || defined(HAVE_DRAGONFLY)
- static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
- #else
- static device_type_t device_type = DEVICE_TYPE_TUN;
- #endif
- #ifdef HAVE_NET_IF_UTUN_H
- static bool setup_utun(void) {
- device_fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
- if(device_fd == -1) {
- logger(LOG_ERR, "Could not open PF_SYSTEM socket: %s\n", strerror(errno));
- return false;
- }
- struct ctl_info info = {};
- strlcpy(info.ctl_name, UTUN_CONTROL_NAME, sizeof(info.ctl_name));
- if(ioctl(device_fd, CTLIOCGINFO, &info) == -1) {
- logger(LOG_ERR, "ioctl(CTLIOCGINFO) failed: %s", strerror(errno));
- return false;
- }
- int unit = -1;
- char *p = strstr(device, "utun"), *e = NULL;
- if(p) {
- unit = strtol(p + 4, &e, 10);
- if(!e) {
- unit = -1;
- }
- }
- struct sockaddr_ctl sc = {
- .sc_id = info.ctl_id,
- .sc_len = sizeof(sc),
- .sc_family = AF_SYSTEM,
- .ss_sysaddr = AF_SYS_CONTROL,
- .sc_unit = unit + 1,
- };
- if(connect(device_fd, (struct sockaddr *)&sc, sizeof(sc)) == -1) {
- logger(LOG_ERR, "Could not connect utun socket: %s\n", strerror(errno));
- return false;
- }
- char name[64] = "";
- socklen_t len = sizeof(name);
- if(getsockopt(device_fd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, name, &len)) {
- iface = xstrdup(device);
- } else {
- iface = xstrdup(name);
- }
- logger(LOG_INFO, "%s is a %s", device, device_info);
- return true;
- }
- #endif
- static bool setup_device(void) {
- // Find out which device file to open
- if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
- if(routing_mode == RMODE_ROUTER) {
- device = xstrdup(DEFAULT_TUN_DEVICE);
- } else {
- device = xstrdup(DEFAULT_TAP_DEVICE);
- }
- }
- // Find out if it's supposed to be a tun or a tap device
- char *type;
- if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
- if(!strcasecmp(type, "tun"))
- /* use default */;
- #ifdef ENABLE_TUNEMU
- else if(!strcasecmp(type, "tunemu")) {
- device_type = DEVICE_TYPE_TUNEMU;
- }
- #endif
- #ifdef HAVE_NET_IF_UTUN_H
- else if(!strcasecmp(type, "utun")) {
- device_type = DEVICE_TYPE_UTUN;
- }
- #endif
- else if(!strcasecmp(type, "tunnohead")) {
- device_type = DEVICE_TYPE_TUN;
- } else if(!strcasecmp(type, "tunifhead")) {
- device_type = DEVICE_TYPE_TUNIFHEAD;
- } else if(!strcasecmp(type, "tap")) {
- device_type = DEVICE_TYPE_TAP;
- } else {
- logger(LOG_ERR, "Unknown device type %s!", type);
- return false;
- }
- } else {
- #ifdef HAVE_NET_IF_UTUN_H
- if(strncmp(device, "utun", 4) == 0 || strncmp(device, "/dev/utun", 9) == 0) {
- device_type = DEVICE_TYPE_UTUN;
- } else
- #endif
- if(strstr(device, "tap") || routing_mode != RMODE_ROUTER) {
- device_type = DEVICE_TYPE_TAP;
- }
- }
- if(routing_mode == RMODE_SWITCH && device_type != DEVICE_TYPE_TAP) {
- logger(LOG_ERR, "Only tap devices support switch mode!");
- return false;
- }
- // Open the device
- switch(device_type) {
- #ifdef ENABLE_TUNEMU
- case DEVICE_TYPE_TUNEMU: {
- char dynamic_name[256] = "";
- device_fd = tunemu_open(dynamic_name);
- }
- break;
- #endif
- #ifdef HAVE_NET_IF_UTUN_H
- case DEVICE_TYPE_UTUN:
- return setup_utun();
- #endif
- default:
- device_fd = open(device, O_RDWR | O_NONBLOCK);
- }
- if(device_fd < 0) {
- logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
- return false;
- }
- #ifdef FD_CLOEXEC
- fcntl(device_fd, F_SETFD, FD_CLOEXEC);
- #endif
- // Guess what the corresponding interface is called
- char *realname = NULL;
- #if defined(HAVE_FDEVNAME)
- realname = fdevname(device_fd);
- #elif defined(HAVE_DEVNAME)
- struct stat buf;
- if(!fstat(device_fd, &buf)) {
- realname = devname(buf.st_rdev, S_IFCHR);
- }
- #endif
- if(!realname) {
- realname = device;
- }
- if(!get_config_string(lookup_config(config_tree, "Interface"), &iface)) {
- iface = xstrdup(strrchr(realname, '/') ? strrchr(realname, '/') + 1 : realname);
- } else if(strcmp(iface, strrchr(realname, '/') ? strrchr(realname, '/') + 1 : realname)) {
- logger(LOG_WARNING, "Warning: Interface does not match Device. $INTERFACE might be set incorrectly.");
- }
- // Configure the device as best as we can
- switch(device_type) {
- default:
- device_type = DEVICE_TYPE_TUN;
- case DEVICE_TYPE_TUN:
- #ifdef TUNSIFHEAD
- {
- const int zero = 0;
- if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof(zero)) == -1) {
- logger(LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
- return false;
- }
- }
- #endif
- #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
- {
- const int mode = IFF_BROADCAST | IFF_MULTICAST;
- ioctl(device_fd, TUNSIFMODE, &mode, sizeof(mode));
- }
- #endif
- device_info = "Generic BSD tun device";
- break;
- case DEVICE_TYPE_TUNIFHEAD:
- #ifdef TUNSIFHEAD
- {
- const int one = 1;
- if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof(one)) == -1) {
- logger(LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
- return false;
- }
- }
- #endif
- #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
- {
- const int mode = IFF_BROADCAST | IFF_MULTICAST;
- ioctl(device_fd, TUNSIFMODE, &mode, sizeof(mode));
- }
- #endif
- device_info = "Generic BSD tun device";
- break;
- case DEVICE_TYPE_TAP:
- if(routing_mode == RMODE_ROUTER) {
- overwrite_mac = true;
- }
- device_info = "Generic BSD tap device";
- #ifdef TAPGIFNAME
- {
- struct ifreq ifr;
- if(ioctl(device_fd, TAPGIFNAME, (void *)&ifr) == 0) {
- if(iface) {
- free(iface);
- }
- iface = xstrdup(ifr.ifr_name);
- }
- }
- #endif
- break;
- #ifdef ENABLE_TUNEMU
- case DEVICE_TYPE_TUNEMU:
- device_info = "BSD tunemu device";
- break;
- #endif
- }
- #ifdef SIOCGIFADDR
- if(overwrite_mac) {
- ioctl(device_fd, SIOCGIFADDR, mymac.x);
- }
- #endif
- logger(LOG_INFO, "%s is a %s", device, device_info);
- return true;
- }
- static void close_device(void) {
- switch(device_type) {
- #ifdef ENABLE_TUNEMU
- case DEVICE_TYPE_TUNEMU:
- tunemu_close(device_fd);
- break;
- #endif
- default:
- close(device_fd);
- }
- free(device);
- free(iface);
- }
- static bool read_packet(vpn_packet_t *packet) {
- int lenin;
- switch(device_type) {
- case DEVICE_TYPE_TUN:
- #ifdef ENABLE_TUNEMU
- case DEVICE_TYPE_TUNEMU:
- if(device_type == DEVICE_TYPE_TUNEMU) {
- lenin = tunemu_read(device_fd, packet->data + 14, MTU - 14);
- } else
- #endif
- lenin = read(device_fd, packet->data + 14, MTU - 14);
- if(lenin <= 0) {
- logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- switch(packet->data[14] >> 4) {
- case 4:
- packet->data[12] = 0x08;
- packet->data[13] = 0x00;
- break;
- case 6:
- packet->data[12] = 0x86;
- packet->data[13] = 0xDD;
- break;
- default:
- ifdebug(TRAFFIC) logger(LOG_ERR,
- "Unknown IP version %d while reading packet from %s %s",
- packet->data[14] >> 4, device_info, device);
- return false;
- }
- memset(packet->data, 0, 12);
- packet->len = lenin + 14;
- break;
- case DEVICE_TYPE_UTUN:
- case DEVICE_TYPE_TUNIFHEAD: {
- if((lenin = read(device_fd, packet->data + 10, MTU - 10)) <= 0) {
- logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- switch(packet->data[14] >> 4) {
- case 4:
- packet->data[12] = 0x08;
- packet->data[13] = 0x00;
- break;
- case 6:
- packet->data[12] = 0x86;
- packet->data[13] = 0xDD;
- break;
- default:
- ifdebug(TRAFFIC) logger(LOG_ERR,
- "Unknown IP version %d while reading packet from %s %s",
- packet->data[14] >> 4, device_info, device);
- return false;
- }
- memset(packet->data, 0, 12);
- packet->len = lenin + 10;
- break;
- }
- case DEVICE_TYPE_TAP:
- if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
- logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- packet->len = lenin;
- break;
- default:
- return false;
- }
- device_total_in += packet->len;
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s",
- packet->len, device_info);
- return true;
- }
- static bool write_packet(vpn_packet_t *packet) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
- packet->len, device_info);
- switch(device_type) {
- case DEVICE_TYPE_TUN:
- if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
- logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- break;
- case DEVICE_TYPE_UTUN:
- case DEVICE_TYPE_TUNIFHEAD: {
- int af = (packet->data[12] << 8) + packet->data[13];
- uint32_t type;
- switch(af) {
- case 0x0800:
- type = htonl(AF_INET);
- break;
- case 0x86DD:
- type = htonl(AF_INET6);
- break;
- default:
- ifdebug(TRAFFIC) logger(LOG_ERR,
- "Unknown address family %x while writing packet to %s %s",
- af, device_info, device);
- return false;
- }
- memcpy(packet->data + 10, &type, sizeof(type));
- if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
- logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
- strerror(errno));
- return false;
- }
- break;
- }
- case DEVICE_TYPE_TAP:
- if(write(device_fd, packet->data, packet->len) < 0) {
- logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- break;
- #ifdef ENABLE_TUNEMU
- case DEVICE_TYPE_TUNEMU:
- if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 0) {
- logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
- device, strerror(errno));
- return false;
- }
- break;
- #endif
- default:
- return false;
- }
- device_total_out += packet->len;
- return true;
- }
- static void dump_device_stats(void) {
- logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
- logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
- logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
- }
- const devops_t os_devops = {
- .setup = setup_device,
- .close = close_device,
- .read = read_packet,
- .write = write_packet,
- .dump_stats = dump_device_stats,
- };
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