2 * WPA Supplicant - Layer2 packet handling
3 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
4 * Copyright (c) 2005, Sam Leffler <sam@errno.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Alternatively, this software may be distributed under the terms of BSD
13 * See README and COPYING for more details.
15 * $FreeBSD: src/usr.sbin/wpa/l2_packet.c,v 1.1.2.2 2006/03/24 01:43:17 sam Exp $
16 * $DragonFly: src/usr.sbin/802_11/l2_packet.c,v 1.2 2006/09/02 05:40:35 sephe Exp $
20 * FreeBSD-specific implementation.
22 #include <sys/types.h>
23 #include <sys/ioctl.h>
24 #include <sys/socket.h>
25 #include <sys/sysctl.h>
29 #include <net/if_dl.h>
30 #include <net/route.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
43 #include "l2_packet.h"
45 struct l2_packet_data {
48 u8 own_addr[ETH_ALEN];
49 void (*rx_callback)(void *ctx, const u8 *src_addr,
50 const u8 *buf, size_t len);
51 void *rx_callback_ctx;
52 int l2_hdr; /* whether to include layer 2 (Ethernet) header data
57 * The version of libpcap in FreeBSD 5.2.1 doesn't have these routines.
58 * Call me insane if you will, but I still run 5.2.1 on my laptop, and
59 * I'd like to use WPA there.
63 pcap_get_selectable_fd(pcap_t *p)
65 return(pcap_fileno(p));
69 * The old version of libpcap opens its BPF descriptor in read-only
70 * mode. We need to temporarily create a new one we can write to.
74 pcap_inject(pcap_t *p, const void *buf, size_t len)
78 char device[sizeof "/dev/bpf0000000000"];
82 * Go through all the minors and find one that isn't in use.
85 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++);
86 fd = open(device, O_RDWR);
87 } while (fd < 0 && errno == EBUSY);
92 bzero((char *)&ifr, sizeof(ifr));
93 ioctl(pcap_fileno(p), BIOCGETIF, (caddr_t)&ifr);
94 ioctl(fd, BIOCSETIF, (caddr_t)&ifr);
96 res = write(fd, buf, len);
104 l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
106 memcpy(addr, l2->own_addr, ETH_ALEN);
111 l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
113 pcap_if_t *devs, *dev;
114 struct pcap_addr *addr;
115 struct sockaddr_in *saddr;
117 char err[PCAP_ERRBUF_SIZE + 1];
119 if (pcap_findalldevs(&devs, err) < 0) {
120 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
124 for (dev = devs; dev && !found; dev = dev->next) {
125 if (strcmp(dev->name, l2->ifname) != 0)
128 addr = dev->addresses;
130 saddr = (struct sockaddr_in *) addr->addr;
131 if (saddr && saddr->sin_family == AF_INET) {
132 snprintf(buf, len, "%s",
133 inet_ntoa(saddr->sin_addr));
141 pcap_freealldevs(devs);
143 return found ? 0 : -1;
147 l2_packet_notify_auth_start(struct l2_packet_data *l2)
152 l2_packet_send(struct l2_packet_data *l2,
153 const u8 *dst_addr, u16 proto, const u8 *buf, size_t len)
157 struct l2_ethhdr *eth = malloc(sizeof(*eth) + len);
160 memcpy(eth->h_dest, dst_addr, ETH_ALEN);
161 memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
162 eth->h_proto = htons(proto);
163 memcpy(eth + 1, buf, len);
164 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
168 return pcap_inject(l2->pcap, buf, len);
173 l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
175 struct l2_packet_data *l2 = eloop_ctx;
176 pcap_t *pcap = sock_ctx;
177 struct pcap_pkthdr hdr;
178 const u_char *packet;
179 struct l2_ethhdr *ethhdr;
183 packet = pcap_next(pcap, &hdr);
185 if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
188 ethhdr = (struct l2_ethhdr *) packet;
190 buf = (unsigned char *) ethhdr;
193 buf = (unsigned char *) (ethhdr + 1);
194 len = hdr.caplen - sizeof(*ethhdr);
196 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
200 l2_packet_init_libpcap(struct l2_packet_data *l2, unsigned short protocol)
202 bpf_u_int32 pcap_maskp, pcap_netp;
203 char pcap_filter[100], pcap_err[PCAP_ERRBUF_SIZE];
204 struct bpf_program pcap_fp;
206 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
207 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
208 if (l2->pcap == NULL) {
209 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
210 fprintf(stderr, "ifname='%s'\n", l2->ifname);
213 if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
214 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
215 fprintf(stderr, "pcap_set_datalinke(DLT_EN10MB): %s\n",
216 pcap_geterr(l2->pcap));
219 snprintf(pcap_filter, sizeof(pcap_filter),
220 "ether dst " MACSTR " and ether proto 0x%x",
221 MAC2STR(l2->own_addr), protocol);
222 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
223 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
227 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
228 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
232 pcap_freecode(&pcap_fp);
234 * When libpcap uses BPF we must enable "immediate mode" to
235 * receive frames right away; otherwise the system may
236 * buffer them for us.
238 { unsigned int on = 1;
239 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) {
240 fprintf(stderr, "%s: cannot enable immediate mode on "
241 "interface %s: %s\n",
242 __func__, l2->ifname, strerror(errno));
243 /* XXX should we fail? */
247 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
248 l2_packet_receive, l2, l2->pcap);
254 l2_packet_deinit_libpcap(struct l2_packet_data *l2)
256 if (l2->pcap != NULL) {
257 eloop_unregister_read_sock(pcap_get_selectable_fd(l2->pcap));
258 pcap_close(l2->pcap);
264 eth_get(const char *device, u8 ea[ETH_ALEN])
266 struct if_msghdr *ifm;
267 struct sockaddr_dl *sdl;
270 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
272 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
274 if ((buf = malloc(len)) == NULL)
276 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
280 for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
281 ifm = (struct if_msghdr *)p;
282 sdl = (struct sockaddr_dl *)(ifm + 1);
283 if (ifm->ifm_type != RTM_IFINFO ||
284 (ifm->ifm_addrs & RTA_IFP) == 0)
286 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
287 memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
289 memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
294 if (p >= buf + len) {
301 struct l2_packet_data *
302 l2_packet_init(const char *ifname, const u8 *own_addr, unsigned short protocol,
303 void (*rx_callback)(void *ctx, const u8 *src_addr,
304 const u8 *buf, size_t len),
305 void *rx_callback_ctx, int l2_hdr)
307 struct l2_packet_data *l2;
309 l2 = malloc(sizeof(struct l2_packet_data));
312 memset(l2, 0, sizeof(*l2));
313 strncpy(l2->ifname, ifname, sizeof(l2->ifname));
314 l2->rx_callback = rx_callback;
315 l2->rx_callback_ctx = rx_callback_ctx;
318 if (eth_get(l2->ifname, l2->own_addr) < 0) {
319 fprintf(stderr, "Failed to get link-level address for "
320 "interface '%s'.\n", l2->ifname);
325 if (l2_packet_init_libpcap(l2, protocol) != 0) {
333 l2_packet_deinit(struct l2_packet_data *l2)
336 l2_packet_deinit_libpcap(l2);