tincd/linux/device.c

/*
    device.c -- Interaction with Linux ethertap and tun/tap device
    Copyright (C) 2001-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
                  2001-2004 Guus Sliepen <guus@tinc-vpn.org>

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id: device.c 1400 2004-11-01 17:02:19Z guus $
*/

#ifdef HAVE_TUNTAP
#ifdef LINUX_IF_TUN_H
#include LINUX_IF_TUN_H
#else
#include <linux/if_tun.h>
#endif
#define DEFAULT_DEVICE "/dev/net/tun"
#else
#define DEFAULT_DEVICE "/dev/tap0"
#endif

typedef enum device_type_t {
        DEVICE_TYPE_ETHERTAP,
        DEVICE_TYPE_TUN,
        DEVICE_TYPE_TAP,
} device_type_t;

int device_fd = -1;
static device_type_t device_type;
char *device;
char *iface;
char ifrname[IFNAMSIZ];
char *device_info;

static int device_total_in = 0;
static int device_total_out = 0;

bool setup_device(void)
{
        struct ifreq ifr;

        cp();

        if(!get_config_string(lookup_config(config_tree, "Device"), &device))
                device = DEFAULT_DEVICE;

        if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
#ifdef HAVE_TUNTAP
                iface = netname;
#else
                iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
#endif
        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 HAVE_TUNTAP
        /* Ok now check if this is an old ethertap or a new tun/tap thingie */

        memset(&ifr, 0, sizeof(ifr));
        if(routing_mode == RMODE_ROUTER) {
                ifr.ifr_flags = IFF_TUN;
                device_type = DEVICE_TYPE_TUN;
                device_info = _("Linux tun/tap device (tun mode)");
        } else {
                ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
                device_type = DEVICE_TYPE_TAP;
                device_info = _("Linux tun/tap device (tap mode)");
        }

        if(iface)
                strncpy(ifr.ifr_name, iface, IFNAMSIZ);

        if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
                strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
                iface = ifrname;
        } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
                logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
                strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
                iface = ifrname;
        } else
#endif
        {
                if(routing_mode == RMODE_ROUTER)
                        overwrite_mac = true;
                device_info = _("Linux ethertap device");
                device_type = DEVICE_TYPE_ETHERTAP;
                iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
        }

        logger(LOG_INFO, _("%s is a %s"), device, device_info);

        return true;
}

void close_device(void)
{
        cp();
        
        close(device_fd);
}

bool read_packet(vpn_packet_t *packet)
{
        int lenin;
        
        cp();

        switch(device_type) {
                case DEVICE_TYPE_TUN:
                        lenin = read(device_fd, packet->data + 10, MTU - 10);

                        if(lenin <= 0) {
                                logger(LOG_ERR, _("Error while reading from %s %s: %s"),
                                           device_info, device, strerror(errno));
                                return false;
                        }

                        packet->len = lenin + 10;
                        break;
                case DEVICE_TYPE_TAP:
                        lenin = read(device_fd, packet->data, MTU);

                        if(lenin <= 0) {
                                logger(LOG_ERR, _("Error while reading from %s %s: %s"),
                                           device_info, device, strerror(errno));
                                return false;
                        }

                        packet->len = lenin;
                        break;
                case DEVICE_TYPE_ETHERTAP:
                        lenin = read(device_fd, packet->data - 2, MTU + 2);

                        if(lenin <= 0) {
                                logger(LOG_ERR, _("Error while reading from %s %s: %s"),
                                           device_info, device, strerror(errno));
                                return false;
                        }

                        packet->len = lenin - 2;
                        break;
        }

        device_total_in += packet->len;

        ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
                           device_info);

        return true;
}

bool write_packet(vpn_packet_t *packet)
{
        cp();

        ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
                           packet->len, device_info);

        switch(device_type) {
                case DEVICE_TYPE_TUN:
                        packet->data[10] = packet->data[11] = 0;
                        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, _("Can't write to %s %s: %s"), device_info, device,
                                           strerror(errno));
                                return false;
                        }
                        break;
                case DEVICE_TYPE_ETHERTAP:
                        *(short int *)(packet->data - 2) = packet->len;

                        if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
                                logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
                                           strerror(errno));
                                return false;
                        }
                        break;
        }

        device_total_out += packet->len;

        return true;
}

void dump_device_stats(void)
{
        cp();

        logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
        logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
        logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
}
Revision:	1.2
Committed:	Thu Mar 17 23:59:38 2005 UTC (19 years, 3 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_9, rel-1_8, rel-2_01, rel-3_0, rel-2_2, rel-2_0, rel-2_21, rel-2_22, rel-2_25, HEAD
Changes since 1.1:	+8 -10 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			device.c -- Interaction with Linux ethertap and tun/tap device
3	pcg	1.2	Copyright (C) 2001-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
4			2001-2004 Guus Sliepen <guus@tinc-vpn.org>
5	pcg	1.1
6			This program is free software; you can redistribute it and/or modify
7			it under the terms of the GNU General Public License as published by
8			the Free Software Foundation; either version 2 of the License, or
9			(at your option) any later version.
10
11			This program is distributed in the hope that it will be useful,
12			but WITHOUT ANY WARRANTY; without even the implied warranty of
13			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			GNU General Public License for more details.
15
16			You should have received a copy of the GNU General Public License
17			along with this program; if not, write to the Free Software
18			Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20	pcg	1.2	$Id: device.c 1400 2004-11-01 17:02:19Z guus $
21	pcg	1.1	*/
22
23			#ifdef HAVE_TUNTAP
24			#ifdef LINUX_IF_TUN_H
25			#include LINUX_IF_TUN_H
26			#else
27			#include <linux/if_tun.h>
28			#endif
29			#define DEFAULT_DEVICE "/dev/net/tun"
30			#else
31			#define DEFAULT_DEVICE "/dev/tap0"
32			#endif
33
34			typedef enum device_type_t {
35			DEVICE_TYPE_ETHERTAP,
36			DEVICE_TYPE_TUN,
37			DEVICE_TYPE_TAP,
38			} device_type_t;
39
40			int device_fd = -1;
41	pcg	1.2	static device_type_t device_type;
42	pcg	1.1	char *device;
43			char *iface;
44			char ifrname[IFNAMSIZ];
45			char *device_info;
46
47	pcg	1.2	static int device_total_in = 0;
48			static int device_total_out = 0;
49	pcg	1.1
50			bool setup_device(void)
51			{
52			struct ifreq ifr;
53
54			cp();
55
56			if(!get_config_string(lookup_config(config_tree, "Device"), &device))
57			device = DEFAULT_DEVICE;
58
59			if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
60			#ifdef HAVE_TUNTAP
61			iface = netname;
62			#else
63			iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
64			#endif
65			device_fd = open(device, O_RDWR \| O_NONBLOCK);
66
67			if(device_fd < 0) {
68			logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
69			return false;
70			}
71
72			#ifdef HAVE_TUNTAP
73			/* Ok now check if this is an old ethertap or a new tun/tap thingie */
74
75			memset(&ifr, 0, sizeof(ifr));
76			if(routing_mode == RMODE_ROUTER) {
77			ifr.ifr_flags = IFF_TUN;
78			device_type = DEVICE_TYPE_TUN;
79			device_info = _("Linux tun/tap device (tun mode)");
80			} else {
81			ifr.ifr_flags = IFF_TAP \| IFF_NO_PI;
82			device_type = DEVICE_TYPE_TAP;
83			device_info = _("Linux tun/tap device (tap mode)");
84			}
85
86			if(iface)
87			strncpy(ifr.ifr_name, iface, IFNAMSIZ);
88
89	pcg	1.2	if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
90	pcg	1.1	strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
91			iface = ifrname;
92	pcg	1.2	} else if(!ioctl(device_fd, (('T' << 8) \| 202), &ifr)) {
93	pcg	1.1	logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
94			strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
95			iface = ifrname;
96			} else
97			#endif
98			{
99			if(routing_mode == RMODE_ROUTER)
100			overwrite_mac = true;
101			device_info = _("Linux ethertap device");
102			device_type = DEVICE_TYPE_ETHERTAP;
103			iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
104			}
105
106			logger(LOG_INFO, _("%s is a %s"), device, device_info);
107
108			return true;
109			}
110
111			void close_device(void)
112			{
113			cp();
114
115			close(device_fd);
116			}
117
118			bool read_packet(vpn_packet_t *packet)
119			{
120			int lenin;
121
122			cp();
123
124			switch(device_type) {
125			case DEVICE_TYPE_TUN:
126			lenin = read(device_fd, packet->data + 10, MTU - 10);
127
128			if(lenin <= 0) {
129			logger(LOG_ERR, _("Error while reading from %s %s: %s"),
130			device_info, device, strerror(errno));
131			return false;
132			}
133
134			packet->len = lenin + 10;
135			break;
136			case DEVICE_TYPE_TAP:
137			lenin = read(device_fd, packet->data, MTU);
138
139			if(lenin <= 0) {
140			logger(LOG_ERR, _("Error while reading from %s %s: %s"),
141			device_info, device, strerror(errno));
142			return false;
143			}
144
145			packet->len = lenin;
146			break;
147			case DEVICE_TYPE_ETHERTAP:
148			lenin = read(device_fd, packet->data - 2, MTU + 2);
149
150			if(lenin <= 0) {
151			logger(LOG_ERR, _("Error while reading from %s %s: %s"),
152			device_info, device, strerror(errno));
153			return false;
154			}
155
156			packet->len = lenin - 2;
157			break;
158			}
159
160			device_total_in += packet->len;
161
162			ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
163			device_info);
164
165			return true;
166			}
167
168			bool write_packet(vpn_packet_t *packet)
169			{
170			cp();
171
172			ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
173			packet->len, device_info);
174
175			switch(device_type) {
176			case DEVICE_TYPE_TUN:
177			packet->data[10] = packet->data[11] = 0;
178			if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
179			logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
180			strerror(errno));
181			return false;
182			}
183			break;
184			case DEVICE_TYPE_TAP:
185			if(write(device_fd, packet->data, packet->len) < 0) {
186			logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
187			strerror(errno));
188			return false;
189			}
190			break;
191			case DEVICE_TYPE_ETHERTAP:
192			(short int )(packet->data - 2) = packet->len;
193
194			if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
195			logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
196			strerror(errno));
197			return false;
198			}
199			break;
200			}
201
202			device_total_out += packet->len;
203
204			return true;
205			}
206
207			void dump_device_stats(void)
208			{
209			cp();
210
211			logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
212			logger(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
213			logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
214			}