xref: /illumos-gate/usr/src/uts/common/io/mac/plugins/mac_wifi.c (revision 71269a2275bf5a143dad6461eee2710a344e7261)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * WiFi MAC Type plugin for the Nemo mac module
28  *
29  * This is a bit of mutant since we pretend to be mostly DL_ETHER.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/modctl.h>
34 #include <sys/dlpi.h>
35 #include <sys/mac.h>
36 #include <sys/mac_wifi.h>
37 #include <sys/dls.h>
38 #include <sys/ethernet.h>
39 #include <sys/byteorder.h>
40 #include <sys/strsun.h>
41 #include <inet/common.h>
42 
43 uint8_t wifi_bcastaddr[]	= { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
44 static uint8_t wifi_ietfmagic[]	= { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
45 static uint8_t wifi_ieeemagic[]	= { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
46 
47 static mac_stat_info_t wifi_stats[] = {
48 	/* statistics described in ieee802.11(5) */
49 { WIFI_STAT_TX_FRAGS, 		"tx_frags",		KSTAT_DATA_UINT32, 0 },
50 { WIFI_STAT_MCAST_TX,		"mcast_tx",		KSTAT_DATA_UINT32, 0 },
51 { WIFI_STAT_TX_FAILED,		"tx_failed",		KSTAT_DATA_UINT32, 0 },
52 { WIFI_STAT_TX_RETRANS,		"tx_retrans",		KSTAT_DATA_UINT32, 0 },
53 { WIFI_STAT_TX_RERETRANS,	"tx_reretrans",		KSTAT_DATA_UINT32, 0 },
54 { WIFI_STAT_RTS_SUCCESS,	"rts_success",		KSTAT_DATA_UINT32, 0 },
55 { WIFI_STAT_RTS_FAILURE,	"rts_failure",		KSTAT_DATA_UINT32, 0 },
56 { WIFI_STAT_ACK_FAILURE,	"ack_failure",		KSTAT_DATA_UINT32, 0 },
57 { WIFI_STAT_RX_FRAGS, 		"rx_frags",		KSTAT_DATA_UINT32, 0 },
58 { WIFI_STAT_MCAST_RX,		"mcast_rx", 		KSTAT_DATA_UINT32, 0 },
59 { WIFI_STAT_FCS_ERRORS,		"fcs_errors", 		KSTAT_DATA_UINT32, 0 },
60 { WIFI_STAT_WEP_ERRORS,		"wep_errors",		KSTAT_DATA_UINT32, 0 },
61 { WIFI_STAT_RX_DUPS,		"rx_dups",		KSTAT_DATA_UINT32, 0 }
62 };
63 
64 static struct modlmisc mac_wifi_modlmisc = {
65 	&mod_miscops,
66 	"WiFi MAC plugin"
67 };
68 
69 static struct modlinkage mac_wifi_modlinkage = {
70 	MODREV_1,
71 	&mac_wifi_modlmisc,
72 	NULL
73 };
74 
75 static mactype_ops_t mac_wifi_type_ops;
76 
77 int
78 _init(void)
79 {
80 	mactype_register_t *mtrp = mactype_alloc(MACTYPE_VERSION);
81 	int err;
82 
83 	/*
84 	 * If `mtrp' is NULL, then this plugin is not compatible with
85 	 * the system's MAC Type plugin framework.
86 	 */
87 	if (mtrp == NULL)
88 		return (ENOTSUP);
89 
90 	mtrp->mtr_ops		= &mac_wifi_type_ops;
91 	mtrp->mtr_ident		= MAC_PLUGIN_IDENT_WIFI;
92 	mtrp->mtr_mactype	= DL_ETHER;
93 	mtrp->mtr_nativetype	= DL_WIFI;
94 	mtrp->mtr_stats		= wifi_stats;
95 	mtrp->mtr_statcount	= A_CNT(wifi_stats);
96 	mtrp->mtr_addrlen	= IEEE80211_ADDR_LEN;
97 	mtrp->mtr_brdcst_addr	= wifi_bcastaddr;
98 
99 	if ((err = mactype_register(mtrp)) == 0) {
100 		if ((err = mod_install(&mac_wifi_modlinkage)) != 0)
101 			(void) mactype_unregister(MAC_PLUGIN_IDENT_WIFI);
102 	}
103 	mactype_free(mtrp);
104 	return (err);
105 }
106 
107 int
108 _fini(void)
109 {
110 	int	err;
111 
112 	if ((err = mactype_unregister(MAC_PLUGIN_IDENT_WIFI)) != 0)
113 		return (err);
114 	return (mod_remove(&mac_wifi_modlinkage));
115 }
116 
117 int
118 _info(struct modinfo *modinfop)
119 {
120 	return (mod_info(&mac_wifi_modlinkage, modinfop));
121 }
122 
123 /*
124  * MAC Type plugin operations
125  */
126 
127 static boolean_t
128 mac_wifi_pdata_verify(void *pdata, size_t pdata_size)
129 {
130 	wifi_data_t *wdp = pdata;
131 
132 	return (pdata_size == sizeof (wifi_data_t) && wdp->wd_opts == 0);
133 }
134 
135 /* ARGSUSED */
136 static int
137 mac_wifi_unicst_verify(const void *addr, void *pdata)
138 {
139 	/* If it's not a group address, then it's a valid unicast address. */
140 	return (IEEE80211_IS_MULTICAST(addr) ? EINVAL : 0);
141 }
142 
143 /* ARGSUSED */
144 static int
145 mac_wifi_multicst_verify(const void *addr, void *pdata)
146 {
147 	/* The address must be a group address. */
148 	if (!IEEE80211_IS_MULTICAST(addr))
149 		return (EINVAL);
150 	/* The address must not be the media broadcast address. */
151 	if (bcmp(addr, wifi_bcastaddr, sizeof (wifi_bcastaddr)) == 0)
152 		return (EINVAL);
153 	return (0);
154 }
155 
156 /*
157  * Verify that `sap' is valid, and return the actual SAP to bind to in
158  * `*bind_sap'.  The WiFI SAP space is identical to Ethernet.
159  */
160 /* ARGSUSED */
161 static boolean_t
162 mac_wifi_sap_verify(uint32_t sap, uint32_t *bind_sap, void *pdata)
163 {
164 	if (sap >= ETHERTYPE_802_MIN && sap <= ETHERTYPE_MAX) {
165 		if (bind_sap != NULL)
166 			*bind_sap = sap;
167 		return (B_TRUE);
168 	}
169 
170 	if (sap <= ETHERMTU) {
171 		if (bind_sap != NULL)
172 			*bind_sap = DLS_SAP_LLC;
173 		return (B_TRUE);
174 	}
175 	return (B_FALSE);
176 }
177 
178 /*
179  * Create a template WiFi datalink header for `sap' packets between `saddr'
180  * and `daddr'.  Any enabled modes and features relevant to building the
181  * header are passed via `pdata'.  Return NULL on failure.
182  */
183 /* ARGSUSED */
184 static mblk_t *
185 mac_wifi_header(const void *saddr, const void *daddr, uint32_t sap,
186     void *pdata, mblk_t *payload, size_t extra_len)
187 {
188 	struct ieee80211_frame	*wh;
189 	struct ieee80211_llc	*llc;
190 	mblk_t			*mp;
191 	wifi_data_t		*wdp = pdata;
192 
193 	if (!mac_wifi_sap_verify(sap, NULL, NULL))
194 		return (NULL);
195 
196 	if ((mp = allocb(WIFI_HDRSIZE + extra_len, BPRI_HI)) == NULL)
197 		return (NULL);
198 	bzero(mp->b_rptr, WIFI_HDRSIZE + extra_len);
199 
200 	/*
201 	 * Fill in the fixed parts of the ieee80211_frame.
202 	 */
203 	wh = (struct ieee80211_frame *)mp->b_rptr;
204 	mp->b_wptr += sizeof (struct ieee80211_frame);
205 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
206 
207 	switch (wdp->wd_opmode) {
208 	case IEEE80211_M_STA:
209 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
210 		IEEE80211_ADDR_COPY(wh->i_addr1, wdp->wd_bssid);
211 		IEEE80211_ADDR_COPY(wh->i_addr2, saddr);
212 		IEEE80211_ADDR_COPY(wh->i_addr3, daddr);
213 		break;
214 
215 	case IEEE80211_M_IBSS:
216 	case IEEE80211_M_AHDEMO:
217 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
218 		IEEE80211_ADDR_COPY(wh->i_addr1, daddr);
219 		IEEE80211_ADDR_COPY(wh->i_addr2, saddr);
220 		IEEE80211_ADDR_COPY(wh->i_addr3, wdp->wd_bssid);
221 		break;
222 
223 	case IEEE80211_M_HOSTAP:
224 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
225 		IEEE80211_ADDR_COPY(wh->i_addr1, daddr);
226 		IEEE80211_ADDR_COPY(wh->i_addr2, wdp->wd_bssid);
227 		IEEE80211_ADDR_COPY(wh->i_addr3, saddr);
228 		break;
229 	}
230 
231 	switch (wdp->wd_secalloc) {
232 	case WIFI_SEC_WEP:
233 		/*
234 		 * Fill in the fixed parts of the WEP-portion of the frame.
235 		 */
236 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
237 		/*
238 		 * The actual contents of the WEP-portion of the packet
239 		 * are computed when the packet is sent -- for now, we
240 		 * just need to account for the size.
241 		 */
242 		mp->b_wptr += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
243 		break;
244 
245 	case WIFI_SEC_WPA:
246 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
247 		mp->b_wptr += IEEE80211_WEP_IVLEN +
248 		    IEEE80211_WEP_KIDLEN + IEEE80211_WEP_EXTIVLEN;
249 		break;
250 
251 	default:
252 		break;
253 	}
254 
255 	/*
256 	 * Fill in the fixed parts of the ieee80211_llc header.
257 	 */
258 	llc = (struct ieee80211_llc *)mp->b_wptr;
259 	mp->b_wptr += sizeof (struct ieee80211_llc);
260 	bcopy(wifi_ietfmagic, llc, sizeof (wifi_ietfmagic));
261 	llc->illc_ether_type = htons(sap);
262 
263 	return (mp);
264 }
265 
266 /*
267  * Use the provided `mp' (which is expected to point to a WiFi header), and
268  * fill in the provided `mhp'.  Return an errno on failure.
269  */
270 /* ARGSUSED */
271 static int
272 mac_wifi_header_info(mblk_t *mp, void *pdata, mac_header_info_t *mhp)
273 {
274 	struct ieee80211_frame	*wh;
275 	struct ieee80211_llc	*llc;
276 	uchar_t			*llcp;
277 	wifi_data_t		*wdp = pdata;
278 
279 	if (MBLKL(mp) < sizeof (struct ieee80211_frame))
280 		return (EINVAL);
281 
282 	wh = (struct ieee80211_frame *)mp->b_rptr;
283 	llcp = mp->b_rptr + sizeof (struct ieee80211_frame);
284 
285 	/*
286 	 * When we receive frames from other hosts, the hardware will have
287 	 * already performed WEP decryption, and thus there will not be a WEP
288 	 * portion.  However, when we receive a loopback copy of our own
289 	 * packets, it will still have a WEP portion.  Skip past it to get to
290 	 * the LLC header.
291 	 */
292 	if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
293 		llcp += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
294 		if (wdp->wd_secalloc == WIFI_SEC_WPA)
295 			llcp += IEEE80211_WEP_EXTIVLEN;
296 	}
297 
298 	if ((uintptr_t)mp->b_wptr - (uintptr_t)llcp <
299 	    sizeof (struct ieee80211_llc))
300 		return (EINVAL);
301 
302 	llc = (struct ieee80211_llc *)llcp;
303 	mhp->mhi_origsap = ntohs(llc->illc_ether_type);
304 	mhp->mhi_bindsap = mhp->mhi_origsap;
305 	mhp->mhi_pktsize = 0;
306 	mhp->mhi_hdrsize = (uintptr_t)llcp + sizeof (*llc) -
307 	    (uintptr_t)mp->b_rptr;
308 
309 	/*
310 	 * Verify the LLC header is one of the known formats.  As per MSFT's
311 	 * convention, if the header is using IEEE 802.1H encapsulation, then
312 	 * treat the LLC header as data.  As per DL_ETHER custom when treating
313 	 * the LLC header as data, set the mhi_bindsap to be DLS_SAP_LLC, and
314 	 * assume mhi_origsap contains the data length.
315 	 */
316 	if (bcmp(llc, wifi_ieeemagic, sizeof (wifi_ieeemagic)) == 0) {
317 		mhp->mhi_bindsap = DLS_SAP_LLC;
318 		mhp->mhi_hdrsize -= sizeof (*llc);
319 		mhp->mhi_pktsize = mhp->mhi_hdrsize + mhp->mhi_origsap;
320 	} else if (bcmp(llc, wifi_ietfmagic, sizeof (wifi_ietfmagic)) != 0) {
321 		return (EINVAL);
322 	}
323 
324 	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
325 	case IEEE80211_FC1_DIR_NODS:
326 		mhp->mhi_daddr = wh->i_addr1;
327 		mhp->mhi_saddr = wh->i_addr2;
328 		break;
329 
330 	case IEEE80211_FC1_DIR_TODS:
331 		mhp->mhi_daddr = wh->i_addr3;
332 		mhp->mhi_saddr = wh->i_addr2;
333 		break;
334 
335 	case IEEE80211_FC1_DIR_FROMDS:
336 		mhp->mhi_daddr = wh->i_addr1;
337 		mhp->mhi_saddr = wh->i_addr3;
338 		break;
339 
340 	case IEEE80211_FC1_DIR_DSTODS:
341 		/* We don't support AP-to-AP mode yet */
342 		return (ENOTSUP);
343 	}
344 
345 	if (mac_wifi_unicst_verify(mhp->mhi_daddr, NULL) == 0)
346 		mhp->mhi_dsttype = MAC_ADDRTYPE_UNICAST;
347 	else if (mac_wifi_multicst_verify(mhp->mhi_daddr, NULL) == 0)
348 		mhp->mhi_dsttype = MAC_ADDRTYPE_MULTICAST;
349 	else
350 		mhp->mhi_dsttype = MAC_ADDRTYPE_BROADCAST;
351 
352 	return (0);
353 }
354 
355 /*
356  * Take the provided `mp' (which is expected to have an Ethernet header), and
357  * return a pointer to an mblk_t with a WiFi header.  Note that the returned
358  * header will not be complete until the driver finishes filling it in prior
359  * to transmit.  If the conversion cannot be performed, return NULL.
360  */
361 static mblk_t *
362 mac_wifi_header_cook(mblk_t *mp, void *pdata)
363 {
364 	struct ether_header	*ehp;
365 	mblk_t			*llmp;
366 
367 	if (MBLKL(mp) < sizeof (struct ether_header))
368 		return (NULL);
369 
370 	ehp = (void *)mp->b_rptr;
371 	llmp = mac_wifi_header(&ehp->ether_shost, &ehp->ether_dhost,
372 	    ntohs(ehp->ether_type), pdata, NULL, 0);
373 	if (llmp == NULL)
374 		return (NULL);
375 
376 	/*
377 	 * The plugin framework guarantees that we have the only reference
378 	 * to the mblk_t, so we can safely modify it.
379 	 */
380 	ASSERT(DB_REF(mp) == 1);
381 	mp->b_rptr += sizeof (struct ether_header);
382 	llmp->b_cont = mp;
383 	return (llmp);
384 }
385 
386 /*
387  * Take the provided `mp' (which is expected to have a WiFi header), and
388  * return a pointer to an mblk_t with an Ethernet header.  If the conversion
389  * cannot be performed, return NULL.
390  */
391 static mblk_t *
392 mac_wifi_header_uncook(mblk_t *mp, void *pdata)
393 {
394 	mac_header_info_t	mhi;
395 	struct ether_header	eh;
396 
397 	if (mac_wifi_header_info(mp, pdata, &mhi) != 0) {
398 		/*
399 		 * The plugin framework guarantees the header is properly
400 		 * formed, so this should never happen.
401 		 */
402 		return (NULL);
403 	}
404 
405 	/*
406 	 * The plugin framework guarantees that we have the only reference to
407 	 * the mblk_t and the underlying dblk_t, so we can safely modify it.
408 	 */
409 	ASSERT(DB_REF(mp) == 1);
410 
411 	IEEE80211_ADDR_COPY(&eh.ether_dhost, mhi.mhi_daddr);
412 	IEEE80211_ADDR_COPY(&eh.ether_shost, mhi.mhi_saddr);
413 	eh.ether_type = htons(mhi.mhi_origsap);
414 
415 	ASSERT(mhi.mhi_hdrsize >= sizeof (struct ether_header));
416 	mp->b_rptr += mhi.mhi_hdrsize - sizeof (struct ether_header);
417 	bcopy(&eh, mp->b_rptr, sizeof (struct ether_header));
418 	return (mp);
419 }
420 
421 static mactype_ops_t mac_wifi_type_ops = {
422 	MTOPS_PDATA_VERIFY | MTOPS_HEADER_COOK | MTOPS_HEADER_UNCOOK,
423 	mac_wifi_unicst_verify,
424 	mac_wifi_multicst_verify,
425 	mac_wifi_sap_verify,
426 	mac_wifi_header,
427 	mac_wifi_header_info,
428 	mac_wifi_pdata_verify,
429 	mac_wifi_header_cook,
430 	mac_wifi_header_uncook
431 };
432