xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb_kdoor.c (revision 69a119caa6570c7077699161b7c28b6ee9f8b0f4)
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 (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #include <sys/types.h>
26 #include <sys/kmem.h>
27 #include <sys/ddi.h>
28 #include <sys/sunddi.h>
29 #include <sys/cmn_err.h>
30 #include <sys/door.h>
31 #include <smbsrv/smb_kproto.h>
32 #include <smbsrv/smb_door.h>
33 
34 static int smb_kdoor_send(smb_doorarg_t *);
35 static int smb_kdoor_receive(smb_doorarg_t *);
36 static int smb_kdoor_upcall_private(smb_doorarg_t *);
37 static int smb_kdoor_encode(smb_doorarg_t *);
38 static int smb_kdoor_decode(smb_doorarg_t *);
39 static void smb_kdoor_sethdr(smb_doorarg_t *, uint32_t);
40 static boolean_t smb_kdoor_chkhdr(smb_doorarg_t *, smb_doorhdr_t *);
41 static void smb_kdoor_free(door_arg_t *);
42 
43 door_handle_t smb_kdoor_hd = NULL;
44 static int smb_kdoor_id = -1;
45 static uint64_t smb_kdoor_ncall = 0;
46 static kmutex_t smb_kdoor_mutex;
47 static kcondvar_t smb_kdoor_cv;
48 
49 void
50 smb_kdoor_init(void)
51 {
52 	mutex_init(&smb_kdoor_mutex, NULL, MUTEX_DEFAULT, NULL);
53 	cv_init(&smb_kdoor_cv, NULL, CV_DEFAULT, NULL);
54 }
55 
56 void
57 smb_kdoor_fini(void)
58 {
59 	smb_kdoor_close();
60 	cv_destroy(&smb_kdoor_cv);
61 	mutex_destroy(&smb_kdoor_mutex);
62 }
63 
64 /*
65  * Open the door.  If the door is already open, close it first
66  * because the door-id has probably changed.
67  */
68 int
69 smb_kdoor_open(int door_id)
70 {
71 	int rc;
72 
73 	smb_kdoor_close();
74 
75 	mutex_enter(&smb_kdoor_mutex);
76 	smb_kdoor_ncall = 0;
77 
78 	if (smb_kdoor_hd == NULL) {
79 		smb_kdoor_id = door_id;
80 		smb_kdoor_hd = door_ki_lookup(door_id);
81 	}
82 
83 	rc = (smb_kdoor_hd == NULL)  ? -1 : 0;
84 	mutex_exit(&smb_kdoor_mutex);
85 	return (rc);
86 }
87 
88 /*
89  * Close the door.
90  */
91 void
92 smb_kdoor_close(void)
93 {
94 	mutex_enter(&smb_kdoor_mutex);
95 
96 	if (smb_kdoor_hd != NULL) {
97 		while (smb_kdoor_ncall > 0)
98 			cv_wait(&smb_kdoor_cv, &smb_kdoor_mutex);
99 
100 		door_ki_rele(smb_kdoor_hd);
101 		smb_kdoor_hd = NULL;
102 	}
103 
104 	mutex_exit(&smb_kdoor_mutex);
105 }
106 
107 /*
108  * Wrapper to handle door call reference counting.
109  */
110 int
111 smb_kdoor_upcall(uint32_t cmd, void *req_data, xdrproc_t req_xdr,
112     void *rsp_data, xdrproc_t rsp_xdr)
113 {
114 	smb_doorarg_t	da;
115 	int		rc;
116 
117 	bzero(&da, sizeof (smb_doorarg_t));
118 	da.da_opcode = cmd;
119 	da.da_opname = smb_doorhdr_opname(cmd);
120 	da.da_req_xdr = req_xdr;
121 	da.da_rsp_xdr = rsp_xdr;
122 	da.da_req_data = req_data;
123 	da.da_rsp_data = rsp_data;
124 
125 	if ((req_data == NULL && req_xdr != NULL) ||
126 	    (rsp_data == NULL && rsp_xdr != NULL)) {
127 		cmn_err(CE_WARN, "smb_kdoor_upcall[%s]: invalid param",
128 		    da.da_opname);
129 		return (-1);
130 	}
131 
132 	if (rsp_data != NULL && rsp_xdr != NULL)
133 		da.da_flags = SMB_DF_ASYNC;
134 
135 	if ((da.da_event = smb_event_create(SMB_EVENT_TIMEOUT)) == NULL)
136 		return (-1);
137 
138 	mutex_enter(&smb_kdoor_mutex);
139 
140 	if (smb_kdoor_hd == NULL) {
141 		mutex_exit(&smb_kdoor_mutex);
142 
143 		if (smb_kdoor_open(smb_kdoor_id) != 0) {
144 			smb_event_destroy(da.da_event);
145 			return (-1);
146 		}
147 
148 		mutex_enter(&smb_kdoor_mutex);
149 	}
150 
151 	++smb_kdoor_ncall;
152 	mutex_exit(&smb_kdoor_mutex);
153 
154 	if (da.da_flags & SMB_DF_ASYNC) {
155 		if ((rc = smb_kdoor_send(&da)) == 0) {
156 			if (smb_event_wait(da.da_event) != 0)
157 				rc = -1;
158 			else
159 				rc = smb_kdoor_receive(&da);
160 		}
161 	} else {
162 		if ((rc = smb_kdoor_encode(&da)) == 0) {
163 			if ((rc = smb_kdoor_upcall_private(&da)) == 0)
164 				rc = smb_kdoor_decode(&da);
165 		}
166 		smb_kdoor_free(&da.da_arg);
167 	}
168 
169 	smb_event_destroy(da.da_event);
170 
171 	mutex_enter(&smb_kdoor_mutex);
172 	if ((--smb_kdoor_ncall) == 0)
173 		cv_signal(&smb_kdoor_cv);
174 	mutex_exit(&smb_kdoor_mutex);
175 	return (rc);
176 }
177 
178 /*
179  * Send the request half of the consumer's door call.
180  */
181 static int
182 smb_kdoor_send(smb_doorarg_t *outer_da)
183 {
184 	smb_doorarg_t	da;
185 	int		rc;
186 
187 	bcopy(outer_da, &da, sizeof (smb_doorarg_t));
188 	da.da_rsp_xdr = NULL;
189 	da.da_rsp_data = NULL;
190 
191 	if (smb_kdoor_encode(&da) != 0)
192 		return (-1);
193 
194 	if ((rc = smb_kdoor_upcall_private(&da)) == 0)
195 		rc = smb_kdoor_decode(&da);
196 
197 	smb_kdoor_free(&da.da_arg);
198 	return (rc);
199 }
200 
201 /*
202  * Get the response half for the consumer's door call.
203  */
204 static int
205 smb_kdoor_receive(smb_doorarg_t *outer_da)
206 {
207 	smb_doorarg_t	da;
208 	int		rc;
209 
210 	bcopy(outer_da, &da, sizeof (smb_doorarg_t));
211 	da.da_opcode = SMB_DR_ASYNC_RESPONSE;
212 	da.da_opname = smb_doorhdr_opname(da.da_opcode);
213 	da.da_flags &= ~SMB_DF_ASYNC;
214 	da.da_req_xdr = NULL;
215 	da.da_req_data = NULL;
216 
217 	if (smb_kdoor_encode(&da) != 0)
218 		return (-1);
219 
220 	if ((rc = smb_kdoor_upcall_private(&da)) == 0)
221 		rc = smb_kdoor_decode(&da);
222 
223 	smb_kdoor_free(&da.da_arg);
224 	return (rc);
225 }
226 
227 /*
228  * We use a copy of the door arg because doorfs may change data_ptr
229  * and we want to detect that when freeing the door buffers.  After
230  * this call, response data must be referenced via rbuf and rsize.
231  */
232 static int
233 smb_kdoor_upcall_private(smb_doorarg_t *da)
234 {
235 	door_arg_t	door_arg;
236 	int		i;
237 	int		rc;
238 
239 	bcopy(&da->da_arg, &door_arg, sizeof (door_arg_t));
240 
241 	for (i = 0; i < SMB_DOOR_CALL_RETRIES; ++i) {
242 		if (smb_server_is_stopping())
243 			return (-1);
244 
245 		if ((rc = door_ki_upcall_limited(smb_kdoor_hd, &door_arg,
246 		    NULL, SIZE_MAX, 0)) == 0)
247 			break;
248 
249 		if (rc != EAGAIN && rc != EINTR)
250 			return (-1);
251 	}
252 
253 	if (rc != 0 || door_arg.data_size == 0 || door_arg.rsize == 0)
254 		return (-1);
255 
256 	da->da_arg.rbuf = door_arg.data_ptr;
257 	da->da_arg.rsize = door_arg.rsize;
258 	return (0);
259 }
260 
261 static int
262 smb_kdoor_encode(smb_doorarg_t *da)
263 {
264 	XDR		xdrs;
265 	char		*buf;
266 	uint32_t	len;
267 
268 	len = xdr_sizeof(smb_doorhdr_xdr, &da->da_hdr);
269 	if (da->da_req_xdr != NULL)
270 		len += xdr_sizeof(da->da_req_xdr, da->da_req_data);
271 
272 	smb_kdoor_sethdr(da, len);
273 
274 	buf = kmem_zalloc(len, KM_SLEEP);
275 	xdrmem_create(&xdrs, buf, len, XDR_ENCODE);
276 
277 	if (!smb_doorhdr_xdr(&xdrs, &da->da_hdr)) {
278 		cmn_err(CE_WARN, "smb_kdoor_encode[%s]: header encode failed",
279 		    da->da_opname);
280 		kmem_free(buf, len);
281 		xdr_destroy(&xdrs);
282 		return (-1);
283 	}
284 
285 	if (da->da_req_xdr != NULL) {
286 		if (!da->da_req_xdr(&xdrs, da->da_req_data)) {
287 			cmn_err(CE_WARN, "smb_kdoor_encode[%s]: encode failed",
288 			    da->da_opname);
289 			kmem_free(buf, len);
290 			xdr_destroy(&xdrs);
291 			return (-1);
292 		}
293 	}
294 
295 	da->da_arg.data_ptr = buf;
296 	da->da_arg.data_size = len;
297 	da->da_arg.desc_ptr = NULL;
298 	da->da_arg.desc_num = 0;
299 	da->da_arg.rbuf = buf;
300 	da->da_arg.rsize = len;
301 
302 	xdr_destroy(&xdrs);
303 	return (0);
304 }
305 
306 /*
307  * Decode the response in rbuf and rsize.
308  */
309 static int
310 smb_kdoor_decode(smb_doorarg_t *da)
311 {
312 	XDR		xdrs;
313 	smb_doorhdr_t	hdr;
314 	char		*rbuf = da->da_arg.rbuf;
315 	uint32_t	rsize = da->da_arg.rsize;
316 
317 	if (rbuf == NULL || rsize == 0) {
318 		cmn_err(CE_WARN, "smb_kdoor_decode[%s]: invalid param",
319 		    da->da_opname);
320 		return (-1);
321 	}
322 
323 	xdrmem_create(&xdrs, rbuf, rsize, XDR_DECODE);
324 
325 	if (!smb_doorhdr_xdr(&xdrs, &hdr)) {
326 		cmn_err(CE_WARN, "smb_kdoor_decode[%s]: header decode failed",
327 		    da->da_opname);
328 		xdr_destroy(&xdrs);
329 		return (-1);
330 	}
331 
332 	if (!smb_kdoor_chkhdr(da, &hdr)) {
333 		xdr_destroy(&xdrs);
334 		return (-1);
335 	}
336 
337 	if (hdr.dh_datalen != 0 && da->da_rsp_xdr != NULL) {
338 		if (!da->da_rsp_xdr(&xdrs, da->da_rsp_data)) {
339 			cmn_err(CE_WARN, "smb_kdoor_decode[%s]: decode failed",
340 			    da->da_opname);
341 			xdr_destroy(&xdrs);
342 			return (-1);
343 		}
344 	}
345 
346 	xdr_destroy(&xdrs);
347 	return (0);
348 }
349 
350 static void
351 smb_kdoor_sethdr(smb_doorarg_t *da, uint32_t datalen)
352 {
353 	smb_doorhdr_t	*hdr = &da->da_hdr;
354 
355 	bzero(hdr, sizeof (smb_doorhdr_t));
356 	hdr->dh_magic = SMB_DOOR_HDR_MAGIC;
357 	hdr->dh_flags = da->da_flags | SMB_DF_SYSSPACE;
358 	hdr->dh_op = da->da_opcode;
359 	hdr->dh_txid = smb_event_txid(da->da_event);
360 	hdr->dh_datalen = datalen;
361 	hdr->dh_door_rc = SMB_DOP_NOT_CALLED;
362 }
363 
364 static boolean_t
365 smb_kdoor_chkhdr(smb_doorarg_t *da, smb_doorhdr_t *hdr)
366 {
367 	if ((hdr->dh_magic != SMB_DOOR_HDR_MAGIC) ||
368 	    (hdr->dh_op != da->da_hdr.dh_op) ||
369 	    (hdr->dh_txid != da->da_hdr.dh_txid)) {
370 		cmn_err(CE_WARN, "smb_kdoor_chkhdr[%s]: invalid header",
371 		    da->da_opname);
372 		return (B_FALSE);
373 	}
374 
375 	if (hdr->dh_door_rc != SMB_DOP_SUCCESS) {
376 		cmn_err(CE_WARN, "smb_kdoor_chkhdr[%s]: call failed: %u",
377 		    da->da_opname, hdr->dh_door_rc);
378 		return (B_FALSE);
379 	}
380 
381 	return (B_TRUE);
382 }
383 
384 /*
385  * Free both the argument and result door buffers regardless of the status
386  * of the up-call.  The doorfs allocates a new buffer if the result buffer
387  * passed by the client is too small.
388  */
389 static void
390 smb_kdoor_free(door_arg_t *arg)
391 {
392 	if (arg->rbuf != NULL && arg->rbuf != arg->data_ptr)
393 		kmem_free(arg->rbuf, arg->rsize);
394 
395 	if (arg->data_ptr != NULL)
396 		kmem_free(arg->data_ptr, arg->data_size);
397 }
398