Merge pull request #12 from cpatulea/master

Support utun devices on Mac OS X.
This commit is contained in:
Erik Ekman 2015-04-08 08:36:01 +02:00
commit b559806a8e

170
src/tun.c
View file

@ -1,6 +1,7 @@
/*
* Copyright (c) 2006-2014 Erik Ekman <yarrick@kryo.se>,
* 2006-2009 Bjorn Andersson <flex@kryo.se>
* 2013 Peter Sagerson <psagers.github@ignorare.net>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
@ -25,6 +26,15 @@
#include <sys/stat.h>
#include <fcntl.h>
#ifdef DARWIN
#include <ctype.h>
#include <sys/kern_control.h>
#include <sys/sys_domain.h>
#include <sys/ioctl.h>
#include <net/if_utun.h>
#include <netinet/ip.h>
#endif
#ifndef IFCONFIGPATH
#define IFCONFIGPATH "PATH=/sbin:/bin "
#endif
@ -315,6 +325,86 @@ open_tun(const char *tun_device)
#else /* BSD and friends */
#ifdef DARWIN
/* Extract the device number from the name, if given. The value returned will
* be suitable for sockaddr_ctl.sc_unit, which means 0 for auto-assign, or
* (n + 1) for manual.
*/
static int
utun_unit(const char *dev)
{
const char *unit_str = dev;
int unit = 0;
while (*unit_str != '\0' && !isdigit(*unit_str))
unit_str++;
if (isdigit(*unit_str))
unit = strtol(unit_str, NULL, 10) + 1;
return unit;
}
static int
open_utun(const char *dev)
{
struct sockaddr_ctl addr;
struct ctl_info info;
char ifname[10];
socklen_t ifname_len = sizeof(ifname);
int fd = -1;
int err = 0;
fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
if (fd < 0) {
warn("open_utun: socket(PF_SYSTEM)");
return -1;
}
/* Look up the kernel controller ID for utun devices. */
bzero(&info, sizeof(info));
strncpy(info.ctl_name, UTUN_CONTROL_NAME, MAX_KCTL_NAME);
err = ioctl(fd, CTLIOCGINFO, &info);
if (err != 0) {
warn("open_utun: ioctl(CTLIOCGINFO)");
close(fd);
return -1;
}
/* Connecting to the socket creates the utun device. */
addr.sc_len = sizeof(addr);
addr.sc_family = AF_SYSTEM;
addr.ss_sysaddr = AF_SYS_CONTROL;
addr.sc_id = info.ctl_id;
addr.sc_unit = utun_unit(dev);
err = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
if (err != 0) {
warn("open_utun: connect");
close(fd);
return -1;
}
/* Retrieve the assigned interface name. */
err = getsockopt(fd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, ifname, &ifname_len);
if (err != 0) {
warn("open_utun: getsockopt(UTUN_OPT_IFNAME)");
close(fd);
return -1;
}
strncpy(if_name, ifname, sizeof(if_name));
fprintf(stderr, "Opened %s\n", ifname);
fd_set_close_on_exec(fd);
return fd;
}
#endif
int
open_tun(const char *tun_device)
{
@ -322,6 +412,15 @@ open_tun(const char *tun_device)
int tun_fd;
char tun_name[50];
#ifdef DARWIN
if (!strncmp(tun_device, "utun", 4)) {
tun_fd = open_utun(tun_device);
if (tun_fd >= 0) {
return tun_fd;
}
}
#endif
if (tun_device != NULL) {
snprintf(tun_name, sizeof(tun_name), "/dev/%s", tun_device);
strncpy(if_name, tun_device, sizeof(if_name));
@ -407,22 +506,32 @@ read_tun(int tun_fd, char *buf, size_t len)
int
write_tun(int tun_fd, char *data, size_t len)
{
#if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD)
data += 4;
len -= 4;
#else /* !FREEBSD/DARWIN */
#if defined (FREEBSD) || defined (NETBSD)
/* FreeBSD/NetBSD has no header */
int header = 0;
#elif defined (DARWIN)
/* Darwin tun has no header, Darwin utun does */
int header = !strncmp(if_name, "utun", 4);
#else /* LINUX/OPENBSD */
int header = 1;
#endif
if (!header) {
data += 4;
len -= 4;
} else {
#ifdef LINUX
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x08;
data[3] = 0x00;
#else /* OPENBSD */
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x00;
data[3] = 0x02;
#endif /* !LINUX */
#endif /* FREEBSD */
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x08;
data[3] = 0x00;
#else /* OPENBSD and DARWIN(utun) */
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x00;
data[3] = 0x02;
#endif
}
if (write(tun_fd, data, len) != len) {
warn("write_tun");
@ -434,20 +543,29 @@ write_tun(int tun_fd, char *data, size_t len)
ssize_t
read_tun(int tun_fd, char *buf, size_t len)
{
#if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD)
/* FreeBSD/Darwin/NetBSD has no header */
int bytes;
memset(buf, 0, 4);
#if defined (FREEBSD) || defined (NETBSD)
/* FreeBSD/NetBSD has no header */
int header = 0;
#elif defined (DARWIN)
/* Darwin tun has no header, Darwin utun does */
int header = !strncmp(if_name, "utun", 4);
#else /* LINUX/OPENBSD */
int header = 1;
#endif
bytes = read(tun_fd, buf + 4, len - 4);
if (bytes < 0) {
return bytes;
if (!header) {
int bytes;
memset(buf, 0, 4);
bytes = read(tun_fd, buf + 4, len - 4);
if (bytes < 0) {
return bytes;
} else {
return bytes + 4;
}
} else {
return bytes + 4;
return read(tun_fd, buf, len);
}
#else /* !FREEBSD */
return read(tun_fd, buf, len);
#endif /* !FREEBSD */
}
#endif