1 /*
2 * hostapd - Authenticator for IEEE 802.11i RSN pre-authentication
3 * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "utils/includes.h"
10
11 #ifdef CONFIG_RSN_PREAUTH
12
13 #include "utils/common.h"
14 #include "utils/eloop.h"
15 #include "l2_packet/l2_packet.h"
16 #include "common/wpa_common.h"
17 #include "eapol_auth/eapol_auth_sm.h"
18 #include "eapol_auth/eapol_auth_sm_i.h"
19 #include "hostapd.h"
20 #include "ap_config.h"
21 #include "ieee802_1x.h"
22 #include "sta_info.h"
23 #include "wpa_auth.h"
24 #include "preauth_auth.h"
25
26 #ifndef ETH_P_PREAUTH
27 #define ETH_P_PREAUTH 0x88C7 /* IEEE 802.11i pre-authentication */
28 #endif /* ETH_P_PREAUTH */
29
30 static const int dot11RSNAConfigPMKLifetime = 43200;
31
32 struct rsn_preauth_interface {
33 struct rsn_preauth_interface *next;
34 struct hostapd_data *hapd;
35 struct l2_packet_data *l2;
36 char *ifname;
37 int ifindex;
38 };
39
40
rsn_preauth_receive(void * ctx,const u8 * src_addr,const u8 * buf,size_t len)41 static void rsn_preauth_receive(void *ctx, const u8 *src_addr,
42 const u8 *buf, size_t len)
43 {
44 struct rsn_preauth_interface *piface = ctx;
45 struct hostapd_data *hapd = piface->hapd;
46 struct ieee802_1x_hdr *hdr;
47 struct sta_info *sta;
48 struct l2_ethhdr *ethhdr;
49
50 wpa_printf(MSG_DEBUG, "RSN: receive pre-auth packet "
51 "from interface '%s'", piface->ifname);
52 if (len < sizeof(*ethhdr) + sizeof(*hdr)) {
53 wpa_printf(MSG_DEBUG, "RSN: too short pre-auth packet "
54 "(len=%lu)", (unsigned long) len);
55 return;
56 }
57
58 ethhdr = (struct l2_ethhdr *) buf;
59 hdr = (struct ieee802_1x_hdr *) (ethhdr + 1);
60
61 if (os_memcmp(ethhdr->h_dest, hapd->own_addr, ETH_ALEN) != 0) {
62 wpa_printf(MSG_DEBUG, "RSN: pre-auth for foreign address "
63 MACSTR, MAC2STR(ethhdr->h_dest));
64 return;
65 }
66
67 sta = ap_get_sta(hapd, ethhdr->h_source);
68 if (sta && (sta->flags & WLAN_STA_ASSOC)) {
69 wpa_printf(MSG_DEBUG, "RSN: pre-auth for already association "
70 "STA " MACSTR, MAC2STR(sta->addr));
71 return;
72 }
73 if (!sta && hdr->type == IEEE802_1X_TYPE_EAPOL_START) {
74 sta = ap_sta_add(hapd, ethhdr->h_source);
75 if (sta == NULL)
76 return;
77 sta->flags = WLAN_STA_PREAUTH;
78
79 ieee802_1x_new_station(hapd, sta);
80 if (sta->eapol_sm == NULL) {
81 ap_free_sta(hapd, sta);
82 sta = NULL;
83 } else {
84 sta->eapol_sm->radius_identifier = -1;
85 sta->eapol_sm->portValid = TRUE;
86 sta->eapol_sm->flags |= EAPOL_SM_PREAUTH;
87 }
88 }
89 if (sta == NULL)
90 return;
91 sta->preauth_iface = piface;
92 ieee802_1x_receive(hapd, ethhdr->h_source, (u8 *) (ethhdr + 1),
93 len - sizeof(*ethhdr));
94 }
95
96
rsn_preauth_iface_add(struct hostapd_data * hapd,const char * ifname)97 static int rsn_preauth_iface_add(struct hostapd_data *hapd, const char *ifname)
98 {
99 struct rsn_preauth_interface *piface;
100
101 wpa_printf(MSG_DEBUG, "RSN pre-auth interface '%s'", ifname);
102
103 piface = os_zalloc(sizeof(*piface));
104 if (piface == NULL)
105 return -1;
106 piface->hapd = hapd;
107
108 piface->ifname = os_strdup(ifname);
109 if (piface->ifname == NULL) {
110 goto fail1;
111 }
112
113 piface->l2 = l2_packet_init(piface->ifname, NULL, ETH_P_PREAUTH,
114 rsn_preauth_receive, piface, 1);
115 if (piface->l2 == NULL) {
116 wpa_printf(MSG_ERROR, "Failed to open register layer 2 access "
117 "to ETH_P_PREAUTH");
118 goto fail2;
119 }
120
121 piface->next = hapd->preauth_iface;
122 hapd->preauth_iface = piface;
123 return 0;
124
125 fail2:
126 os_free(piface->ifname);
127 fail1:
128 os_free(piface);
129 return -1;
130 }
131
132
rsn_preauth_iface_deinit(struct hostapd_data * hapd)133 void rsn_preauth_iface_deinit(struct hostapd_data *hapd)
134 {
135 struct rsn_preauth_interface *piface, *prev;
136
137 piface = hapd->preauth_iface;
138 hapd->preauth_iface = NULL;
139 while (piface) {
140 prev = piface;
141 piface = piface->next;
142 l2_packet_deinit(prev->l2);
143 os_free(prev->ifname);
144 os_free(prev);
145 }
146 }
147
148
rsn_preauth_iface_init(struct hostapd_data * hapd)149 int rsn_preauth_iface_init(struct hostapd_data *hapd)
150 {
151 char *tmp, *start, *end;
152
153 if (hapd->conf->rsn_preauth_interfaces == NULL)
154 return 0;
155
156 tmp = os_strdup(hapd->conf->rsn_preauth_interfaces);
157 if (tmp == NULL)
158 return -1;
159 start = tmp;
160 for (;;) {
161 while (*start == ' ')
162 start++;
163 if (*start == '\0')
164 break;
165 end = os_strchr(start, ' ');
166 if (end)
167 *end = '\0';
168
169 if (rsn_preauth_iface_add(hapd, start)) {
170 rsn_preauth_iface_deinit(hapd);
171 os_free(tmp);
172 return -1;
173 }
174
175 if (end)
176 start = end + 1;
177 else
178 break;
179 }
180 os_free(tmp);
181 return 0;
182 }
183
184
rsn_preauth_finished_cb(void * eloop_ctx,void * timeout_ctx)185 static void rsn_preauth_finished_cb(void *eloop_ctx, void *timeout_ctx)
186 {
187 struct hostapd_data *hapd = eloop_ctx;
188 struct sta_info *sta = timeout_ctx;
189 wpa_printf(MSG_DEBUG, "RSN: Removing pre-authentication STA entry for "
190 MACSTR, MAC2STR(sta->addr));
191 ap_free_sta(hapd, sta);
192 }
193
194
rsn_preauth_finished(struct hostapd_data * hapd,struct sta_info * sta,int success)195 void rsn_preauth_finished(struct hostapd_data *hapd, struct sta_info *sta,
196 int success)
197 {
198 const u8 *key;
199 size_t len;
200 hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
201 HOSTAPD_LEVEL_INFO, "pre-authentication %s",
202 success ? "succeeded" : "failed");
203
204 key = ieee802_1x_get_key(sta->eapol_sm, &len);
205 if (len > PMK_LEN)
206 len = PMK_LEN;
207 if (success && key) {
208 if (wpa_auth_pmksa_add_preauth(hapd->wpa_auth, key, len,
209 sta->addr,
210 dot11RSNAConfigPMKLifetime,
211 sta->eapol_sm) == 0) {
212 hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
213 HOSTAPD_LEVEL_DEBUG,
214 "added PMKSA cache entry (pre-auth)");
215 } else {
216 hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
217 HOSTAPD_LEVEL_DEBUG,
218 "failed to add PMKSA cache entry "
219 "(pre-auth)");
220 }
221 }
222
223 /*
224 * Finish STA entry removal from timeout in order to avoid freeing
225 * STA data before the caller has finished processing.
226 */
227 eloop_register_timeout(0, 0, rsn_preauth_finished_cb, hapd, sta);
228 }
229
230
rsn_preauth_send(struct hostapd_data * hapd,struct sta_info * sta,u8 * buf,size_t len)231 void rsn_preauth_send(struct hostapd_data *hapd, struct sta_info *sta,
232 u8 *buf, size_t len)
233 {
234 struct rsn_preauth_interface *piface;
235 struct l2_ethhdr *ethhdr;
236
237 piface = hapd->preauth_iface;
238 while (piface) {
239 if (piface == sta->preauth_iface)
240 break;
241 piface = piface->next;
242 }
243
244 if (piface == NULL) {
245 wpa_printf(MSG_DEBUG, "RSN: Could not find pre-authentication "
246 "interface for " MACSTR, MAC2STR(sta->addr));
247 return;
248 }
249
250 ethhdr = os_malloc(sizeof(*ethhdr) + len);
251 if (ethhdr == NULL)
252 return;
253
254 os_memcpy(ethhdr->h_dest, sta->addr, ETH_ALEN);
255 os_memcpy(ethhdr->h_source, hapd->own_addr, ETH_ALEN);
256 ethhdr->h_proto = host_to_be16(ETH_P_PREAUTH);
257 os_memcpy(ethhdr + 1, buf, len);
258
259 if (l2_packet_send(piface->l2, sta->addr, ETH_P_PREAUTH, (u8 *) ethhdr,
260 sizeof(*ethhdr) + len) < 0) {
261 wpa_printf(MSG_ERROR, "Failed to send preauth packet using "
262 "l2_packet_send\n");
263 }
264 os_free(ethhdr);
265 }
266
267
rsn_preauth_free_station(struct hostapd_data * hapd,struct sta_info * sta)268 void rsn_preauth_free_station(struct hostapd_data *hapd, struct sta_info *sta)
269 {
270 eloop_cancel_timeout(rsn_preauth_finished_cb, hapd, sta);
271 }
272
273 #endif /* CONFIG_RSN_PREAUTH */
274