1 /* $NetBSD: tap.c,v 1.1 2008/08/17 13:20:57 plunky Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2008 Iain Hibbert 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* $FreeBSD$ */ 31 32 #include <sys/cdefs.h> 33 __RCSID("$NetBSD: tap.c,v 1.1 2008/08/17 13:20:57 plunky Exp $"); 34 35 #include <sys/types.h> 36 #include <sys/param.h> 37 #include <sys/ioctl.h> 38 #include <sys/uio.h> 39 40 #include <net/if_tap.h> 41 42 #include <fcntl.h> 43 #include <libutil.h> 44 #include <paths.h> 45 #include <stdio.h> 46 #include <unistd.h> 47 48 #define L2CAP_SOCKET_CHECKED 49 #include "btpand.h" 50 51 static bool tap_send(channel_t *, packet_t *); 52 static bool tap_recv(packet_t *); 53 54 void 55 tap_init(void) 56 { 57 channel_t *chan; 58 struct ifreq ifr; 59 int fd, s; 60 char pidfile[PATH_MAX]; 61 62 fd = open(interface_name, O_RDWR); 63 if (fd == -1) { 64 log_err("Could not open \"%s\": %m", interface_name); 65 exit(EXIT_FAILURE); 66 } 67 68 memset(&ifr, 0, sizeof(ifr)); 69 if (ioctl(fd, TAPGIFNAME, &ifr) == -1) { 70 log_err("Could not get interface name: %m"); 71 exit(EXIT_FAILURE); 72 } 73 74 s = socket(AF_INET, SOCK_DGRAM, 0); 75 if (s == -1) { 76 log_err("Could not open PF_LINK socket: %m"); 77 exit(EXIT_FAILURE); 78 } 79 80 ifr.ifr_addr.sa_family = AF_LINK; 81 ifr.ifr_addr.sa_len = ETHER_ADDR_LEN; 82 b2eaddr(ifr.ifr_addr.sa_data, &local_bdaddr); 83 84 if (ioctl(s, SIOCSIFLLADDR, &ifr) == -1) { 85 log_err("Could not set %s physical address: %m", ifr.ifr_name); 86 exit(EXIT_FAILURE); 87 } 88 89 if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1) { 90 log_err("Could not get interface flags: %m"); 91 exit(EXIT_FAILURE); 92 } 93 94 if ((ifr.ifr_flags & IFF_UP) == 0) { 95 ifr.ifr_flags |= IFF_UP; 96 97 if (ioctl(s, SIOCSIFFLAGS, &ifr) == -1) { 98 log_err("Could not set IFF_UP: %m"); 99 exit(EXIT_FAILURE); 100 } 101 } 102 103 close(s); 104 105 log_info("Using interface %s with addr %s", ifr.ifr_name, 106 ether_ntoa((struct ether_addr *)&ifr.ifr_addr.sa_data)); 107 108 chan = channel_alloc(); 109 if (chan == NULL) 110 exit(EXIT_FAILURE); 111 112 chan->send = tap_send; 113 chan->recv = tap_recv; 114 chan->mru = ETHER_HDR_LEN + ETHER_MAX_LEN; 115 memcpy(chan->raddr, ifr.ifr_addr.sa_data, ETHER_ADDR_LEN); 116 memcpy(chan->laddr, ifr.ifr_addr.sa_data, ETHER_ADDR_LEN); 117 chan->state = CHANNEL_OPEN; 118 if (!channel_open(chan, fd)) 119 exit(EXIT_FAILURE); 120 121 snprintf(pidfile, sizeof(pidfile), "%s/%s.pid", 122 _PATH_VARRUN, ifr.ifr_name); 123 chan->pfh = pidfile_open(pidfile, 0600, NULL); 124 if (chan->pfh == NULL) 125 log_err("can't create pidfile"); 126 else if (pidfile_write(chan->pfh) < 0) { 127 log_err("can't write pidfile"); 128 pidfile_remove(chan->pfh); 129 chan->pfh = NULL; 130 } 131 } 132 133 static bool 134 tap_send(channel_t *chan, packet_t *pkt) 135 { 136 struct iovec iov[4]; 137 ssize_t nw; 138 139 iov[0].iov_base = pkt->dst; 140 iov[0].iov_len = ETHER_ADDR_LEN; 141 iov[1].iov_base = pkt->src; 142 iov[1].iov_len = ETHER_ADDR_LEN; 143 iov[2].iov_base = pkt->type; 144 iov[2].iov_len = ETHER_TYPE_LEN; 145 iov[3].iov_base = pkt->ptr; 146 iov[3].iov_len = pkt->len; 147 148 /* tap device write never fails */ 149 nw = writev(chan->fd, iov, __arraycount(iov)); 150 assert(nw > 0); 151 152 return true; 153 } 154 155 static bool 156 tap_recv(packet_t *pkt) 157 { 158 159 if (pkt->len < ETHER_HDR_LEN) 160 return false; 161 162 pkt->dst = pkt->ptr; 163 packet_adj(pkt, ETHER_ADDR_LEN); 164 pkt->src = pkt->ptr; 165 packet_adj(pkt, ETHER_ADDR_LEN); 166 pkt->type = pkt->ptr; 167 packet_adj(pkt, ETHER_TYPE_LEN); 168 169 return true; 170 } 171