1 /*
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>
5 *
6 * This software may be distributed under the terms of the BSD license.
7 * See README for more details.
8 */
9
10 #include "includes.h"
11 #include <sys/param.h>
12 #if defined(__APPLE__) || defined(__GLIBC__) || defined(__DragonFly__)
13 #include <net/bpf.h>
14 #endif /* __APPLE__ */
15 #include <pcap.h>
16
17 #include <sys/ioctl.h>
18 #ifdef __sun__
19 #include <libdlpi.h>
20 #else /* __sun__ */
21 #include <sys/sysctl.h>
22 #endif /* __sun__ */
23
24 #include <net/if.h>
25 #include <net/if_dl.h>
26 #include <net/route.h>
27 #include <netinet/in.h>
28
29 #include "common.h"
30 #include "eloop.h"
31 #include "l2_packet.h"
32
33
34 static const u8 pae_group_addr[ETH_ALEN] =
35 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };
36
37 struct l2_packet_data {
38 pcap_t *pcap;
39 char ifname[100];
40 u8 own_addr[ETH_ALEN];
41 void (*rx_callback)(void *ctx, const u8 *src_addr,
42 const u8 *buf, size_t len);
43 void *rx_callback_ctx;
44 int l2_hdr; /* whether to include layer 2 (Ethernet) header data
45 * buffers */
46 };
47
48
l2_packet_get_own_addr(struct l2_packet_data * l2,u8 * addr)49 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
50 {
51 os_memcpy(addr, l2->own_addr, ETH_ALEN);
52 return 0;
53 }
54
55
l2_packet_send(struct l2_packet_data * l2,const u8 * dst_addr,u16 proto,const u8 * buf,size_t len)56 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
57 const u8 *buf, size_t len)
58 {
59 if (!l2->l2_hdr) {
60 int ret;
61 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len);
62 if (eth == NULL)
63 return -1;
64 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN);
65 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
66 eth->h_proto = htons(proto);
67 os_memcpy(eth + 1, buf, len);
68 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
69 os_free(eth);
70 return ret;
71 } else
72 return pcap_inject(l2->pcap, buf, len);
73 }
74
75
l2_packet_receive(int sock,void * eloop_ctx,void * sock_ctx)76 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
77 {
78 struct l2_packet_data *l2 = eloop_ctx;
79 pcap_t *pcap = sock_ctx;
80 struct pcap_pkthdr hdr;
81 const u_char *packet;
82 struct l2_ethhdr *ethhdr;
83 unsigned char *buf;
84 size_t len;
85
86 packet = pcap_next(pcap, &hdr);
87
88 if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
89 return;
90
91 ethhdr = (struct l2_ethhdr *) packet;
92 if (l2->l2_hdr) {
93 buf = (unsigned char *) ethhdr;
94 len = hdr.caplen;
95 } else {
96 buf = (unsigned char *) (ethhdr + 1);
97 len = hdr.caplen - sizeof(*ethhdr);
98 }
99 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
100 }
101
102
l2_packet_init_libpcap(struct l2_packet_data * l2,unsigned short protocol)103 static int l2_packet_init_libpcap(struct l2_packet_data *l2,
104 unsigned short protocol)
105 {
106 bpf_u_int32 pcap_maskp, pcap_netp;
107 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE];
108 struct bpf_program pcap_fp;
109
110 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
111 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
112 if (l2->pcap == NULL) {
113 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
114 fprintf(stderr, "ifname='%s'\n", l2->ifname);
115 return -1;
116 }
117 if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
118 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
119 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n",
120 pcap_geterr(l2->pcap));
121 return -1;
122 }
123 os_snprintf(pcap_filter, sizeof(pcap_filter),
124 "not ether src " MACSTR " and "
125 "( ether dst " MACSTR " or ether dst " MACSTR " ) and "
126 "ether proto 0x%x",
127 MAC2STR(l2->own_addr), /* do not receive own packets */
128 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr),
129 protocol);
130 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
131 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
132 return -1;
133 }
134
135 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
136 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
137 return -1;
138 }
139
140 pcap_freecode(&pcap_fp);
141 #ifndef __sun__
142 /*
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.
146 */
147 {
148 unsigned int on = 1;
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? */
154 }
155 }
156 #endif /* __sun__ */
157
158 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
159 l2_packet_receive, l2, l2->pcap);
160
161 return 0;
162 }
163
164
eth_get(const char * device,u8 ea[ETH_ALEN])165 static int eth_get(const char *device, u8 ea[ETH_ALEN])
166 {
167 #ifdef __sun__
168 dlpi_handle_t dh;
169 u32 physaddrlen = DLPI_PHYSADDR_MAX;
170 u8 physaddr[DLPI_PHYSADDR_MAX];
171 int retval;
172
173 retval = dlpi_open(device, &dh, 0);
174 if (retval != DLPI_SUCCESS) {
175 wpa_printf(MSG_ERROR, "dlpi_open error: %s",
176 dlpi_strerror(retval));
177 return -1;
178 }
179
180 retval = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, physaddr,
181 &physaddrlen);
182 if (retval != DLPI_SUCCESS) {
183 wpa_printf(MSG_ERROR, "dlpi_get_physaddr error: %s",
184 dlpi_strerror(retval));
185 dlpi_close(dh);
186 return -1;
187 }
188 os_memcpy(ea, physaddr, ETH_ALEN);
189 dlpi_close(dh);
190 #else /* __sun__ */
191 struct if_msghdr *ifm;
192 struct sockaddr_dl *sdl;
193 u_char *p, *buf;
194 size_t len;
195 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
196
197 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
198 return -1;
199 if ((buf = os_malloc(len)) == NULL)
200 return -1;
201 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
202 os_free(buf);
203 return -1;
204 }
205 for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
206 ifm = (struct if_msghdr *)p;
207 sdl = (struct sockaddr_dl *)(ifm + 1);
208 if (ifm->ifm_type != RTM_IFINFO ||
209 (ifm->ifm_addrs & RTA_IFP) == 0)
210 continue;
211 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
212 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
213 continue;
214 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
215 break;
216 }
217 os_free(buf);
218
219 if (p >= buf + len) {
220 errno = ESRCH;
221 return -1;
222 }
223 #endif /* __sun__ */
224 return 0;
225 }
226
227
l2_packet_init(const char * ifname,const u8 * own_addr,unsigned short protocol,void (* rx_callback)(void * ctx,const u8 * src_addr,const u8 * buf,size_t len),void * rx_callback_ctx,int l2_hdr)228 struct l2_packet_data * l2_packet_init(
229 const char *ifname, const u8 *own_addr, unsigned short protocol,
230 void (*rx_callback)(void *ctx, const u8 *src_addr,
231 const u8 *buf, size_t len),
232 void *rx_callback_ctx, int l2_hdr)
233 {
234 struct l2_packet_data *l2;
235
236 l2 = os_zalloc(sizeof(struct l2_packet_data));
237 if (l2 == NULL)
238 return NULL;
239 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
240 l2->rx_callback = rx_callback;
241 l2->rx_callback_ctx = rx_callback_ctx;
242 l2->l2_hdr = l2_hdr;
243
244 if (eth_get(l2->ifname, l2->own_addr) < 0) {
245 fprintf(stderr, "Failed to get link-level address for "
246 "interface '%s'.\n", l2->ifname);
247 os_free(l2);
248 return NULL;
249 }
250
251 if (l2_packet_init_libpcap(l2, protocol)) {
252 os_free(l2);
253 return NULL;
254 }
255
256 return l2;
257 }
258
259
l2_packet_init_bridge(const char * br_ifname,const char * ifname,const u8 * own_addr,unsigned short protocol,void (* rx_callback)(void * ctx,const u8 * src_addr,const u8 * buf,size_t len),void * rx_callback_ctx,int l2_hdr)260 struct l2_packet_data * l2_packet_init_bridge(
261 const char *br_ifname, const char *ifname, const u8 *own_addr,
262 unsigned short protocol,
263 void (*rx_callback)(void *ctx, const u8 *src_addr,
264 const u8 *buf, size_t len),
265 void *rx_callback_ctx, int l2_hdr)
266 {
267 return l2_packet_init(br_ifname, own_addr, protocol, rx_callback,
268 rx_callback_ctx, l2_hdr);
269 }
270
271
l2_packet_deinit(struct l2_packet_data * l2)272 void l2_packet_deinit(struct l2_packet_data *l2)
273 {
274 if (l2 != NULL) {
275 if (l2->pcap) {
276 eloop_unregister_read_sock(
277 pcap_get_selectable_fd(l2->pcap));
278 pcap_close(l2->pcap);
279 }
280 os_free(l2);
281 }
282 }
283
284
l2_packet_get_ip_addr(struct l2_packet_data * l2,char * buf,size_t len)285 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
286 {
287 pcap_if_t *devs, *dev;
288 struct pcap_addr *addr;
289 struct sockaddr_in *saddr;
290 int found = 0;
291 char err[PCAP_ERRBUF_SIZE + 1];
292
293 if (pcap_findalldevs(&devs, err) < 0) {
294 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
295 return -1;
296 }
297
298 for (dev = devs; dev && !found; dev = dev->next) {
299 if (os_strcmp(dev->name, l2->ifname) != 0)
300 continue;
301
302 addr = dev->addresses;
303 while (addr) {
304 saddr = (struct sockaddr_in *) addr->addr;
305 if (saddr && saddr->sin_family == AF_INET) {
306 os_strlcpy(buf, inet_ntoa(saddr->sin_addr),
307 len);
308 found = 1;
309 break;
310 }
311 addr = addr->next;
312 }
313 }
314
315 pcap_freealldevs(devs);
316
317 return found ? 0 : -1;
318 }
319
320
l2_packet_notify_auth_start(struct l2_packet_data * l2)321 void l2_packet_notify_auth_start(struct l2_packet_data *l2)
322 {
323 }
324
325
l2_packet_set_packet_filter(struct l2_packet_data * l2,enum l2_packet_filter_type type)326 int l2_packet_set_packet_filter(struct l2_packet_data *l2,
327 enum l2_packet_filter_type type)
328 {
329 return -1;
330 }
331