1 /*
2 device.c -- raw socket
3 Copyright (C) 2002-2005 Ivo Timmermans,
4 2002-2014 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 const char *device_info = "raw_socket";
37
38 static uint64_t device_total_in = 0;
39 static uint64_t device_total_out = 0;
40
setup_device(void)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
49 if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
50 device = xstrdup(iface);
51 }
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 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
66
67 if(ioctl(device_fd, SIOCGIFINDEX, &ifr)) {
68 close(device_fd);
69 logger(LOG_ERR, "Can't find interface %s: %s", ifr.ifr_ifrn.ifrn_name, strerror(errno));
70 return false;
71 }
72
73 memset(&sa, 0, sizeof(sa));
74 sa.sll_family = AF_PACKET;
75 sa.sll_protocol = htons(ETH_P_ALL);
76 sa.sll_ifindex = ifr.ifr_ifindex;
77
78 if(bind(device_fd, (struct sockaddr *) &sa, (socklen_t) sizeof(sa))) {
79 logger(LOG_ERR, "Could not bind %s to %s: %s", device, ifr.ifr_ifrn.ifrn_name, strerror(errno));
80 return false;
81 }
82
83 logger(LOG_INFO, "%s is a %s", device, device_info);
84
85 return true;
86 }
87
close_device(void)88 static void close_device(void) {
89 close(device_fd);
90
91 free(device);
92 free(iface);
93 }
94
read_packet(vpn_packet_t * packet)95 static bool read_packet(vpn_packet_t *packet) {
96 int lenin;
97
98 if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
99 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
100 device, strerror(errno));
101 return false;
102 }
103
104 packet->len = lenin;
105
106 device_total_in += packet->len;
107
108 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
109 device_info);
110
111 return true;
112 }
113
write_packet(vpn_packet_t * packet)114 static bool write_packet(vpn_packet_t *packet) {
115 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
116 packet->len, device_info);
117
118 if(write(device_fd, packet->data, packet->len) < 0) {
119 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
120 strerror(errno));
121 return false;
122 }
123
124 device_total_out += packet->len;
125
126 return true;
127 }
128
dump_device_stats(void)129 static void dump_device_stats(void) {
130 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
131 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
132 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
133 }
134
135 const devops_t raw_socket_devops = {
136 .setup = setup_device,
137 .close = close_device,
138 .read = read_packet,
139 .write = write_packet,
140 .dump_stats = dump_device_stats,
141 };
142
143 #else
144
not_supported(void)145 static bool not_supported(void) {
146 logger(LOG_ERR, "Raw socket device not supported on this platform");
147 return false;
148 }
149
150 const devops_t raw_socket_devops = {
151 .setup = not_supported,
152 .close = NULL,
153 .read = NULL,
154 .write = NULL,
155 .dump_stats = NULL,
156 };
157 #endif
158