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[oweals/tinc.git] / src / raw_socket_device.c
1 /*
2     device.c -- raw socket
3     Copyright (C) 2002-2005 Ivo Timmermans,
4                   2002-2012 Guus Sliepen <guus@tinc-vpn.org>
5
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 along
17     with this program; if not, write to the Free Software Foundation, Inc.,
18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include "system.h"
22
23 #ifdef HAVE_NETPACKET_PACKET_H
24 #include <netpacket/packet.h>
25 #endif
26
27 #include "conf.h"
28 #include "device.h"
29 #include "net.h"
30 #include "logger.h"
31 #include "utils.h"
32 #include "route.h"
33 #include "xalloc.h"
34
35 #if defined(PF_PACKET) && defined(ETH_P_ALL) && defined(AF_PACKET) && defined(SIOCGIFINDEX)
36 static char *device_info;
37
38 static uint64_t device_total_in = 0;
39 static uint64_t device_total_out = 0;
40
41 static bool setup_device(void) {
42         struct ifreq ifr;
43         struct sockaddr_ll sa;
44
45         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
46                 iface = xstrdup("eth0");
47
48         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
49                 device = xstrdup(iface);
50
51         device_info = "raw socket";
52
53         if((device_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL))) < 0) {
54                 logger(LOG_ERR, "Could not open %s: %s", device_info,
55                            strerror(errno));
56                 return false;
57         }
58
59 #ifdef FD_CLOEXEC
60         fcntl(device_fd, F_SETFD, FD_CLOEXEC);
61 #endif
62
63         memset(&ifr, 0, sizeof(ifr));
64         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
65         if(ioctl(device_fd, SIOCGIFINDEX, &ifr)) {
66                 close(device_fd);
67                 logger(LOG_ERR, "Can't find interface %s: %s", iface,
68                            strerror(errno));
69                 return false;
70         }
71
72         memset(&sa, 0, sizeof(sa));
73         sa.sll_family = AF_PACKET;
74         sa.sll_protocol = htons(ETH_P_ALL);
75         sa.sll_ifindex = ifr.ifr_ifindex;
76
77         if(bind(device_fd, (struct sockaddr *) &sa, (socklen_t) sizeof(sa))) {
78                 logger(LOG_ERR, "Could not bind %s to %s: %s", device, iface, strerror(errno));
79                 return false;
80         }
81
82         logger(LOG_INFO, "%s is a %s", device, device_info);
83
84         return true;
85 }
86
87 static void close_device(void) {
88         close(device_fd);
89
90         free(device);
91         free(iface);
92 }
93
94 static bool read_packet(vpn_packet_t *packet) {
95         int lenin;
96
97         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
98                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
99                            device, strerror(errno));
100                 return false;
101         }
102
103         packet->len = lenin;
104
105         device_total_in += packet->len;
106
107         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
108                            device_info);
109
110         return true;
111 }
112
113 static bool write_packet(vpn_packet_t *packet) {
114         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
115                            packet->len, device_info);
116
117         if(write(device_fd, packet->data, packet->len) < 0) {
118                 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
119                            strerror(errno));
120                 return false;
121         }
122
123         device_total_out += packet->len;
124
125         return true;
126 }
127
128 static void dump_device_stats(void) {
129         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
130         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
131         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
132 }
133
134 const devops_t raw_socket_devops = {
135         .setup = setup_device,
136         .close = close_device,
137         .read = read_packet,
138         .write = write_packet,
139         .dump_stats = dump_device_stats,
140 };
141
142 #else
143
144 static bool not_supported(void) {
145         logger(LOG_ERR, "Raw socket device not supported on this platform");
146         return false;
147 }
148
149 const devops_t raw_socket_devops = {
150         .setup = not_supported,
151         .close = NULL,
152         .read = NULL,
153         .write = NULL,
154         .dump_stats = NULL,
155 };
156 #endif