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: releng/10.2/usr.sbin/bluetooth/btpand/tap.c 187938 2009-01-30 22:23:21Z emax $ */
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#include "btpand.h"
47
48static bool tap_send(channel_t *, packet_t *);
49static bool tap_recv(packet_t *);
50
51void
52tap_init(void)
53{
54	channel_t *chan;
55	struct ifreq ifr;
56	int fd, s;
57	char pidfile[PATH_MAX];
58
59	fd = open(interface_name, O_RDWR);
60	if (fd == -1) {
61		log_err("Could not open \"%s\": %m", interface_name);
62		exit(EXIT_FAILURE);
63	}
64
65	memset(&ifr, 0, sizeof(ifr));
66	if (ioctl(fd, TAPGIFNAME, &ifr) == -1) {
67		log_err("Could not get interface name: %m");
68		exit(EXIT_FAILURE);
69	}
70
71	s = socket(AF_INET, SOCK_DGRAM, 0);
72	if (s == -1) {
73		log_err("Could not open PF_LINK socket: %m");
74		exit(EXIT_FAILURE);
75	}
76
77	ifr.ifr_addr.sa_family = AF_LINK;
78	ifr.ifr_addr.sa_len = ETHER_ADDR_LEN;
79	b2eaddr(ifr.ifr_addr.sa_data, &local_bdaddr);
80
81	if (ioctl(s, SIOCSIFLLADDR, &ifr) == -1) {
82		log_err("Could not set %s physical address: %m", ifr.ifr_name);
83		exit(EXIT_FAILURE);
84	}
85
86	if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1) {
87		log_err("Could not get interface flags: %m");
88		exit(EXIT_FAILURE);
89	}
90
91	if ((ifr.ifr_flags & IFF_UP) == 0) {
92		ifr.ifr_flags |= IFF_UP;
93
94		if (ioctl(s, SIOCSIFFLAGS, &ifr) == -1) {
95			log_err("Could not set IFF_UP: %m");
96			exit(EXIT_FAILURE);
97		}
98	}
99
100	close(s);
101
102	log_info("Using interface %s with addr %s", ifr.ifr_name,
103		ether_ntoa((struct ether_addr *)&ifr.ifr_addr.sa_data));
104
105	chan = channel_alloc();
106	if (chan == NULL)
107		exit(EXIT_FAILURE);
108
109	chan->send = tap_send;
110	chan->recv = tap_recv;
111	chan->mru = ETHER_HDR_LEN + ETHER_MAX_LEN;
112	memcpy(chan->raddr, ifr.ifr_addr.sa_data, ETHER_ADDR_LEN);
113	memcpy(chan->laddr, ifr.ifr_addr.sa_data, ETHER_ADDR_LEN);
114	chan->state = CHANNEL_OPEN;
115	if (!channel_open(chan, fd))
116		exit(EXIT_FAILURE);
117
118	snprintf(pidfile, sizeof(pidfile), "%s/%s.pid",
119		_PATH_VARRUN, ifr.ifr_name);
120	chan->pfh = pidfile_open(pidfile, 0600, NULL);
121	if (chan->pfh == NULL)
122		log_err("can't create pidfile");
123	else if (pidfile_write(chan->pfh) < 0) {
124		log_err("can't write pidfile");
125		pidfile_remove(chan->pfh);
126		chan->pfh = NULL;
127	}
128}
129
130static bool
131tap_send(channel_t *chan, packet_t *pkt)
132{
133	struct iovec iov[4];
134	ssize_t nw;
135
136	iov[0].iov_base = pkt->dst;
137	iov[0].iov_len = ETHER_ADDR_LEN;
138	iov[1].iov_base = pkt->src;
139	iov[1].iov_len = ETHER_ADDR_LEN;
140	iov[2].iov_base = pkt->type;
141	iov[2].iov_len = ETHER_TYPE_LEN;
142	iov[3].iov_base = pkt->ptr;
143	iov[3].iov_len = pkt->len;
144
145	/* tap device write never fails */
146	nw = writev(chan->fd, iov, __arraycount(iov));
147	assert(nw > 0);
148
149	return true;
150}
151
152static bool
153tap_recv(packet_t *pkt)
154{
155
156	if (pkt->len < ETHER_HDR_LEN)
157		return false;
158
159	pkt->dst = pkt->ptr;
160	packet_adj(pkt, ETHER_ADDR_LEN);
161	pkt->src = pkt->ptr;
162	packet_adj(pkt, ETHER_ADDR_LEN);
163	pkt->type = pkt->ptr;
164	packet_adj(pkt, ETHER_TYPE_LEN);
165
166	return true;
167}
168