1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "btstack_network.c" 39 40 /* 41 * btstack_network.c 42 * Implementation of the btstack_network.h interface for POSIX systems 43 */ 44 45 46 #include "btstack_network.h" 47 48 #include "btstack_config.h" 49 50 #include <arpa/inet.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <ifaddrs.h> 54 #include <stdint.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include <net/if_arp.h> 61 62 #ifdef __APPLE__ 63 #include <net/if.h> 64 #include <net/if_types.h> 65 66 #include <netinet/if_ether.h> 67 #include <netinet/in.h> 68 #endif 69 70 #include <sys/ioctl.h> 71 #include <sys/param.h> 72 #include <sys/socket.h> 73 #include <sys/stat.h> 74 #include <sys/types.h> 75 76 #ifdef __linux 77 #include <linux/if.h> 78 #include <linux/if_tun.h> 79 #endif 80 81 #include "btstack.h" 82 83 static int tap_fd = -1; 84 static uint8_t network_buffer[BNEP_MTU_MIN]; 85 static size_t network_buffer_len = 0; 86 static char tap_dev_name[16]; 87 88 #ifdef __APPLE__ 89 // tuntaposx provides fixed set of tapX devices 90 static const char * tap_dev = "/dev/tap0"; 91 static const char * tap_dev_name_template = "tap0"; 92 #endif 93 94 #ifdef __linux 95 // Linux uses single control device to bring up tunX or tapX interface 96 static const char * tap_dev = "/dev/net/tun"; 97 static const char * tap_dev_name_template = "bnep%d"; 98 #endif 99 100 static btstack_data_source_t tap_dev_ds; 101 102 static void (*btstack_network_send_packet_callback)(const uint8_t * packet, uint16_t size); 103 104 /* 105 * @text Listing processTapData shows how a packet is received from the TAP network interface 106 * and forwarded over the BNEP connection. 107 * 108 * After successfully reading a network packet, the call to 109 * the *bnep_can_send_packet_now* function checks, if BTstack can forward 110 * a network packet now. If that's not possible, the received data stays 111 * in the network buffer and the data source elements is removed from the 112 * run loop. The *process_tap_dev_data* function will not be called until 113 * the data source is registered again. This provides a basic flow control. 114 */ 115 116 /* LISTING_START(processTapData): Process incoming network packets */ 117 static void process_tap_dev_data(btstack_data_source_t *ds, btstack_data_source_callback_type_t callback_type) 118 { 119 UNUSED(ds); 120 UNUSED(callback_type); 121 122 ssize_t len; 123 len = read(ds->source.fd, network_buffer, sizeof(network_buffer)); 124 if (len <= 0){ 125 fprintf(stderr, "TAP: Error while reading: %s\n", strerror(errno)); 126 return; 127 } 128 129 network_buffer_len = len; 130 131 // disable reading from netif 132 btstack_run_loop_disable_data_source_callbacks(&tap_dev_ds, DATA_SOURCE_CALLBACK_READ); 133 134 // let client now 135 (*btstack_network_send_packet_callback)(network_buffer, network_buffer_len); 136 } 137 138 /** 139 * @brief Initialize network interface 140 * @param send_packet_callback 141 */ 142 void btstack_network_init(void (*send_packet_callback)(const uint8_t * packet, uint16_t size)){ 143 btstack_network_send_packet_callback = send_packet_callback; 144 } 145 146 /** 147 * @text This code requries a TUN/TAP interface to connect the Bluetooth network interface 148 * with the native system. It has been tested on Linux and OS X, but should work on any 149 * system that provides TUN/TAP with minor modifications. 150 * 151 * On Linux, TUN/TAP is available by default. On OS X, tuntaposx from 152 * http://tuntaposx.sourceforge.net needs to be installed. 153 * 154 * The *tap_alloc* function sets up a virtual network interface with the given Bluetooth Address. 155 * It is rather low-level as it sets up and configures a network interface. 156 * 157 * @brief Bring up network interfacd 158 * @param network_address 159 * @return 0 if ok 160 */ 161 int btstack_network_up(bd_addr_t network_address){ 162 163 struct ifreq ifr; 164 int fd_dev; 165 int fd_socket; 166 167 if( (fd_dev = open(tap_dev, O_RDWR)) < 0 ) { 168 fprintf(stderr, "TAP: Error opening %s: %s\n", tap_dev, strerror(errno)); 169 return -1; 170 } 171 172 #ifdef __linux 173 memset(&ifr, 0, sizeof(ifr)); 174 ifr.ifr_flags = IFF_TAP | IFF_NO_PI; 175 strncpy(ifr.ifr_name, tap_dev_name_template, IFNAMSIZ); // device name pattern 176 177 int err; 178 if( (err = ioctl(fd_dev, TUNSETIFF, (void *) &ifr)) < 0 ) { 179 fprintf(stderr, "TAP: Error setting device name: %s\n", strerror(errno)); 180 close(fd_dev); 181 return -1; 182 } 183 strcpy(tap_dev_name, ifr.ifr_name); 184 #endif 185 #ifdef __APPLE__ 186 strcpy(tap_dev_name, tap_dev_name_template); 187 #endif 188 189 fd_socket = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); 190 if (fd_socket < 0) { 191 close(fd_dev); 192 fprintf(stderr, "TAP: Error opening netlink socket: %s\n", strerror(errno)); 193 return -1; 194 } 195 196 // Configure the MAC address of the newly created bnep(x) 197 // device to the local bd_address 198 memset (&ifr, 0, sizeof(struct ifreq)); 199 strcpy(ifr.ifr_name, tap_dev_name); 200 #ifdef __linux 201 ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; 202 memcpy(ifr.ifr_hwaddr.sa_data, network_address, sizeof(bd_addr_t)); 203 if (ioctl(fd_socket, SIOCSIFHWADDR, &ifr) == -1) { 204 close(fd_dev); 205 close(fd_socket); 206 fprintf(stderr, "TAP: Error setting hw addr: %s\n", strerror(errno)); 207 exit(1); 208 return -1; 209 } 210 #endif 211 #ifdef __APPLE__ 212 ifr.ifr_addr.sa_len = ETHER_ADDR_LEN; 213 ifr.ifr_addr.sa_family = AF_LINK; 214 (void)memcpy(ifr.ifr_addr.sa_data, network_address, ETHER_ADDR_LEN); 215 if (ioctl(fd_socket, SIOCSIFLLADDR, &ifr) == -1) { 216 close(fd_dev); 217 close(fd_socket); 218 fprintf(stderr, "TAP: Error setting hw addr: %s\n", strerror(errno)); 219 exit(1); 220 return -1; 221 } 222 #endif 223 224 // Bring the interface up 225 if (ioctl(fd_socket, SIOCGIFFLAGS, &ifr) == -1) { 226 close(fd_dev); 227 close(fd_socket); 228 fprintf(stderr, "TAP: Error reading interface flags: %s\n", strerror(errno)); 229 return -1; 230 } 231 232 if ((ifr.ifr_flags & IFF_UP) == 0) { 233 ifr.ifr_flags |= IFF_UP; 234 235 if (ioctl(fd_socket, SIOCSIFFLAGS, &ifr) == -1) { 236 close(fd_dev); 237 close(fd_socket); 238 fprintf(stderr, "TAP: Error set IFF_UP: %s\n", strerror(errno)); 239 return -1; 240 } 241 } 242 243 close(fd_socket); 244 245 tap_fd = fd_dev; 246 log_info("BNEP device \"%s\" allocated", tap_dev_name); 247 248 /* Create and register a new runloop data source */ 249 btstack_run_loop_set_data_source_fd(&tap_dev_ds, tap_fd); 250 btstack_run_loop_set_data_source_handler(&tap_dev_ds, &process_tap_dev_data); 251 btstack_run_loop_add_data_source(&tap_dev_ds); 252 btstack_run_loop_enable_data_source_callbacks(&tap_dev_ds, DATA_SOURCE_CALLBACK_READ); 253 254 return 0;; 255 } 256 257 /** 258 * @brief Get network name after network was activated 259 * @note e.g. tapX on Linux, might not be useful on all platforms 260 * @returns network name 261 */ 262 const char * btstack_network_get_name(void){ 263 return tap_dev_name; 264 } 265 266 /** 267 * @brief Bring up network interfacd 268 * @param network_address 269 * @return 0 if ok 270 */ 271 int btstack_network_down(void){ 272 log_info("BNEP channel closed"); 273 btstack_run_loop_remove_data_source(&tap_dev_ds); 274 tap_fd = -1; 275 return 0; 276 } 277 278 /** 279 * @brief Receive packet on network interface, e.g., forward packet to TCP/IP stack 280 * @param packet 281 * @param size 282 */ 283 void btstack_network_process_packet(const uint8_t * packet, uint16_t size){ 284 285 if (tap_fd < 0) return; 286 // Write out the ethernet frame to the tap device 287 288 int rc = write(tap_fd, packet, size); 289 if (rc < 0) { 290 log_error("TAP: Could not write to TAP device: %s", strerror(errno)); 291 } else 292 if (rc != size) { 293 log_error("TAP: Package written only partially %d of %d bytes", rc, size); 294 } 295 } 296 297 /** 298 * @brief Notify network interface that packet from send_packet_callback was sent and the next packet can be delivered. 299 */ 300 void btstack_network_packet_sent(void){ 301 302 network_buffer_len = 0; 303 304 // Re-enable the tap device data source 305 btstack_run_loop_enable_data_source_callbacks(&tap_dev_ds, DATA_SOURCE_CALLBACK_READ); 306 } 307