1 /*
2     device.c -- VDE plug
3     Copyright (C) 2013 Guus Sliepen <guus@tinc-vpn.org>
4 
5     This program is free software; you can redistribute it and/or modify
6     it under the terms of the GNU General Public License as published by
7     the Free Software Foundation; either version 2 of the License, or
8     (at your option) any later version.
9 
10     This program is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13     GNU General Public License for more details.
14 
15     You should have received a copy of the GNU General Public License along
16     with this program; if not, write to the Free Software Foundation, Inc.,
17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19 
20 #include "system.h"
21 
22 #include <libvdeplug_dyn.h>
23 
24 #include "conf.h"
25 #include "device.h"
26 #include "names.h"
27 #include "net.h"
28 #include "logger.h"
29 #include "utils.h"
30 #include "route.h"
31 #include "xalloc.h"
32 
33 static struct vdepluglib plug;
34 static struct vdeconn *conn = NULL;
35 static int port = 0;
36 static char *group = NULL;
37 static const char *device_info = "VDE socket";
38 
setup_device(void)39 static bool setup_device(void) {
40 	libvdeplug_dynopen(plug);
41 
42 	if(!plug.dl_handle) {
43 		logger(DEBUG_ALWAYS, LOG_ERR, "Could not open libvdeplug library!");
44 		return false;
45 	}
46 
47 	if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
48 		xasprintf(&device, RUNSTATEDIR "/vde.ctl");
49 	}
50 
51 	get_config_string(lookup_config(config_tree, "Interface"), &iface);
52 
53 	get_config_int(lookup_config(config_tree, "VDEPort"), &port);
54 
55 	get_config_string(lookup_config(config_tree, "VDEGroup"), &group);
56 
57 	struct vde_open_args args = {
58 		.port = port,
59 		.group = group,
60 		.mode = 0700,
61 	};
62 
63 	conn = plug.vde_open(device, identname, &args);
64 
65 	if(!conn) {
66 		logger(DEBUG_ALWAYS, LOG_ERR, "Could not open VDE socket %s", device);
67 		return false;
68 	}
69 
70 	device_fd = plug.vde_datafd(conn);
71 
72 #ifdef FD_CLOEXEC
73 	fcntl(device_fd, F_SETFD, FD_CLOEXEC);
74 #endif
75 
76 	logger(DEBUG_ALWAYS, LOG_INFO, "%s is a %s", device, device_info);
77 
78 	if(routing_mode == RMODE_ROUTER) {
79 		overwrite_mac = true;
80 	}
81 
82 	return true;
83 }
84 
close_device(void)85 static void close_device(void) {
86 	if(conn) {
87 		plug.vde_close(conn);
88 		conn = NULL;
89 	}
90 
91 	if(plug.dl_handle) {
92 		libvdeplug_dynclose(plug);
93 	}
94 
95 	free(device);
96 	device = NULL;
97 
98 	free(iface);
99 	iface = NULL;
100 
101 	device_info = NULL;
102 }
103 
read_packet(vpn_packet_t * packet)104 static bool read_packet(vpn_packet_t *packet) {
105 	int lenin = (ssize_t)plug.vde_recv(conn, DATA(packet), MTU, 0);
106 
107 	if(lenin <= 0) {
108 		logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info, device, strerror(errno));
109 		event_exit();
110 		return false;
111 	}
112 
113 	packet->len = lenin;
114 
115 	logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s", packet->len, device_info);
116 
117 	return true;
118 }
119 
write_packet(vpn_packet_t * packet)120 static bool write_packet(vpn_packet_t *packet) {
121 	if((ssize_t)plug.vde_send(conn, DATA(packet), packet->len, 0) < 0) {
122 		if(errno != EINTR && errno != EAGAIN) {
123 			logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
124 			event_exit();
125 		}
126 
127 		return false;
128 	}
129 
130 	return true;
131 }
132 
133 const devops_t vde_devops = {
134 	.setup = setup_device,
135 	.close = close_device,
136 	.read = read_packet,
137 	.write = write_packet,
138 };
139