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