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.
19 #include <sys/ioctl.h>
20 #include <sys/sysctl.h>
23 #include <net/if_dl.h>
24 #include <net/route.h>
25 #include <netinet/in.h>
29 #include "l2_packet.h"
32 static const u8 pae_group_addr[ETH_ALEN] =
33 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };
35 struct l2_packet_data {
38 u8 own_addr[ETH_ALEN];
39 void (*rx_callback)(void *ctx, const u8 *src_addr,
40 const u8 *buf, size_t len);
41 void *rx_callback_ctx;
42 int l2_hdr; /* whether to include layer 2 (Ethernet) header data
47 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
49 os_memcpy(addr, l2->own_addr, ETH_ALEN);
54 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
55 const u8 *buf, size_t len)
59 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len);
62 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN);
63 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
64 eth->h_proto = htons(proto);
65 os_memcpy(eth + 1, buf, len);
66 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
70 return pcap_inject(l2->pcap, buf, len);
74 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
76 struct l2_packet_data *l2 = eloop_ctx;
77 pcap_t *pcap = sock_ctx;
78 struct pcap_pkthdr hdr;
80 struct l2_ethhdr *ethhdr;
84 packet = pcap_next(pcap, &hdr);
86 if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
89 ethhdr = (struct l2_ethhdr *) packet;
91 buf = (unsigned char *) ethhdr;
94 buf = (unsigned char *) (ethhdr + 1);
95 len = hdr.caplen - sizeof(*ethhdr);
97 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
101 static int l2_packet_init_libpcap(struct l2_packet_data *l2,
102 unsigned short protocol)
104 bpf_u_int32 pcap_maskp, pcap_netp;
105 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE];
106 struct bpf_program pcap_fp;
108 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
109 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
110 if (l2->pcap == NULL) {
111 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
112 fprintf(stderr, "ifname='%s'\n", l2->ifname);
115 if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
116 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
117 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n",
118 pcap_geterr(l2->pcap));
121 os_snprintf(pcap_filter, sizeof(pcap_filter),
122 "not ether src " MACSTR " and "
123 "( ether dst " MACSTR " or ether dst " MACSTR " ) and "
125 MAC2STR(l2->own_addr), /* do not receive own packets */
126 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr),
128 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
129 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
133 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
134 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
138 pcap_freecode(&pcap_fp);
140 * When libpcap uses BPF we must enable "immediate mode" to
141 * receive frames right away; otherwise the system may
142 * buffer them for us.
146 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) {
147 fprintf(stderr, "%s: cannot enable immediate mode on "
148 "interface %s: %s\n",
149 __func__, l2->ifname, strerror(errno));
150 /* XXX should we fail? */
154 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
155 l2_packet_receive, l2, l2->pcap);
161 static int eth_get(const char *device, u8 ea[ETH_ALEN])
163 struct if_msghdr *ifm;
164 struct sockaddr_dl *sdl;
167 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
169 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
171 if ((buf = os_malloc(len)) == NULL)
173 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
177 for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
178 ifm = (struct if_msghdr *)p;
179 sdl = (struct sockaddr_dl *)(ifm + 1);
180 if (ifm->ifm_type != RTM_IFINFO ||
181 (ifm->ifm_addrs & RTA_IFP) == 0)
183 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
184 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
186 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
191 if (p >= buf + len) {
199 struct l2_packet_data * l2_packet_init(
200 const char *ifname, const u8 *own_addr, unsigned short protocol,
201 void (*rx_callback)(void *ctx, const u8 *src_addr,
202 const u8 *buf, size_t len),
203 void *rx_callback_ctx, int l2_hdr)
205 struct l2_packet_data *l2;
207 l2 = os_zalloc(sizeof(struct l2_packet_data));
210 os_strncpy(l2->ifname, ifname, sizeof(l2->ifname));
211 l2->rx_callback = rx_callback;
212 l2->rx_callback_ctx = rx_callback_ctx;
215 if (eth_get(l2->ifname, l2->own_addr) < 0) {
216 fprintf(stderr, "Failed to get link-level address for "
217 "interface '%s'.\n", l2->ifname);
222 if (l2_packet_init_libpcap(l2, protocol)) {
231 void l2_packet_deinit(struct l2_packet_data *l2)
235 eloop_unregister_read_sock(
236 pcap_get_selectable_fd(l2->pcap));
237 pcap_close(l2->pcap);
244 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
246 pcap_if_t *devs, *dev;
247 struct pcap_addr *addr;
248 struct sockaddr_in *saddr;
250 char err[PCAP_ERRBUF_SIZE + 1];
252 if (pcap_findalldevs(&devs, err) < 0) {
253 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
257 for (dev = devs; dev && !found; dev = dev->next) {
258 if (os_strcmp(dev->name, l2->ifname) != 0)
261 addr = dev->addresses;
263 saddr = (struct sockaddr_in *) addr->addr;
264 if (saddr && saddr->sin_family == AF_INET) {
265 os_snprintf(buf, len, "%s",
266 inet_ntoa(saddr->sin_addr));
274 pcap_freealldevs(devs);
276 return found ? 0 : -1;
280 void l2_packet_notify_auth_start(struct l2_packet_data *l2)