2 * WPA Supplicant - Layer2 packet handling with FreeBSD
3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.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.
17 #if defined(__APPLE__) || defined(__GLIBC__)
19 #endif /* __APPLE__ */
22 #include <sys/ioctl.h>
23 #include <sys/sysctl.h>
26 #include <net/if_dl.h>
27 #include <net/route.h>
28 #include <netinet/in.h>
32 #include "l2_packet.h"
35 static const u8 pae_group_addr[ETH_ALEN] =
36 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };
38 struct l2_packet_data {
41 u8 own_addr[ETH_ALEN];
42 void (*rx_callback)(void *ctx, const u8 *src_addr,
43 const u8 *buf, size_t len);
44 void *rx_callback_ctx;
45 int l2_hdr; /* whether to include layer 2 (Ethernet) header data
50 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
52 os_memcpy(addr, l2->own_addr, ETH_ALEN);
57 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
58 const u8 *buf, size_t len)
62 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len);
65 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN);
66 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
67 eth->h_proto = htons(proto);
68 os_memcpy(eth + 1, buf, len);
69 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
73 return pcap_inject(l2->pcap, buf, len);
77 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
79 struct l2_packet_data *l2 = eloop_ctx;
80 pcap_t *pcap = sock_ctx;
81 struct pcap_pkthdr hdr;
83 struct l2_ethhdr *ethhdr;
87 packet = pcap_next(pcap, &hdr);
89 if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
92 ethhdr = (struct l2_ethhdr *) packet;
94 buf = (unsigned char *) ethhdr;
97 buf = (unsigned char *) (ethhdr + 1);
98 len = hdr.caplen - sizeof(*ethhdr);
100 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
104 static int l2_packet_init_libpcap(struct l2_packet_data *l2,
105 unsigned short protocol)
107 bpf_u_int32 pcap_maskp, pcap_netp;
108 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE];
109 struct bpf_program pcap_fp;
111 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
112 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
113 if (l2->pcap == NULL) {
114 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
115 fprintf(stderr, "ifname='%s'\n", l2->ifname);
118 if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
119 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
120 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n",
121 pcap_geterr(l2->pcap));
124 os_snprintf(pcap_filter, sizeof(pcap_filter),
125 "not ether src " MACSTR " and "
126 "( ether dst " MACSTR " or ether dst " MACSTR " ) and "
128 MAC2STR(l2->own_addr), /* do not receive own packets */
129 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr),
131 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
132 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
136 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
137 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
141 pcap_freecode(&pcap_fp);
143 * When libpcap uses BPF we must enable "immediate mode" to
144 * receive frames right away; otherwise the system may
145 * buffer them for us.
149 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) {
150 fprintf(stderr, "%s: cannot enable immediate mode on "
151 "interface %s: %s\n",
152 __func__, l2->ifname, strerror(errno));
153 /* XXX should we fail? */
157 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
158 l2_packet_receive, l2, l2->pcap);
164 static int eth_get(const char *device, u8 ea[ETH_ALEN])
166 struct if_msghdr *ifm;
167 struct sockaddr_dl *sdl;
170 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
172 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
174 if ((buf = os_malloc(len)) == NULL)
176 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
180 for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
181 ifm = (struct if_msghdr *)p;
182 sdl = (struct sockaddr_dl *)(ifm + 1);
183 if (ifm->ifm_type != RTM_IFINFO ||
184 (ifm->ifm_addrs & RTA_IFP) == 0)
186 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
187 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
189 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
194 if (p >= buf + len) {
202 struct l2_packet_data * l2_packet_init(
203 const char *ifname, const u8 *own_addr, unsigned short protocol,
204 void (*rx_callback)(void *ctx, const u8 *src_addr,
205 const u8 *buf, size_t len),
206 void *rx_callback_ctx, int l2_hdr)
208 struct l2_packet_data *l2;
210 l2 = os_zalloc(sizeof(struct l2_packet_data));
213 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
214 l2->rx_callback = rx_callback;
215 l2->rx_callback_ctx = rx_callback_ctx;
218 if (eth_get(l2->ifname, l2->own_addr) < 0) {
219 fprintf(stderr, "Failed to get link-level address for "
220 "interface '%s'.\n", l2->ifname);
225 if (l2_packet_init_libpcap(l2, protocol)) {
234 void l2_packet_deinit(struct l2_packet_data *l2)
238 eloop_unregister_read_sock(
239 pcap_get_selectable_fd(l2->pcap));
240 pcap_close(l2->pcap);
247 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
249 pcap_if_t *devs, *dev;
250 struct pcap_addr *addr;
251 struct sockaddr_in *saddr;
253 char err[PCAP_ERRBUF_SIZE + 1];
255 if (pcap_findalldevs(&devs, err) < 0) {
256 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
260 for (dev = devs; dev && !found; dev = dev->next) {
261 if (os_strcmp(dev->name, l2->ifname) != 0)
264 addr = dev->addresses;
266 saddr = (struct sockaddr_in *) addr->addr;
267 if (saddr && saddr->sin_family == AF_INET) {
268 os_strlcpy(buf, inet_ntoa(saddr->sin_addr),
277 pcap_freealldevs(devs);
279 return found ? 0 : -1;
283 void l2_packet_notify_auth_start(struct l2_packet_data *l2)