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1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org> | |
4 | * Copyright (C) 2018 Samsung Electronics Co., Ltd. | |
5 | */ | |
6 | ||
7 | #include "glob.h" | |
8 | #include "nterr.h" | |
9 | #include "smb2pdu.h" | |
10 | #include "smb_common.h" | |
11 | #include "smbstatus.h" | |
12 | #include "mgmt/user_session.h" | |
13 | #include "connection.h" | |
14 | ||
15 | static int check_smb2_hdr(struct smb2_hdr *hdr) | |
16 | { | |
17 | /* | |
18 | * Make sure that this really is an SMB, that it is a response. | |
19 | */ | |
20 | if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) | |
21 | return 1; | |
22 | return 0; | |
23 | } | |
24 | ||
25 | /* | |
26 | * The following table defines the expected "StructureSize" of SMB2 requests | |
27 | * in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests. | |
28 | * | |
29 | * Note that commands are defined in smb2pdu.h in le16 but the array below is | |
30 | * indexed by command in host byte order | |
31 | */ | |
32 | static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { | |
33 | /* SMB2_NEGOTIATE */ cpu_to_le16(36), | |
34 | /* SMB2_SESSION_SETUP */ cpu_to_le16(25), | |
35 | /* SMB2_LOGOFF */ cpu_to_le16(4), | |
36 | /* SMB2_TREE_CONNECT */ cpu_to_le16(9), | |
37 | /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4), | |
38 | /* SMB2_CREATE */ cpu_to_le16(57), | |
39 | /* SMB2_CLOSE */ cpu_to_le16(24), | |
40 | /* SMB2_FLUSH */ cpu_to_le16(24), | |
41 | /* SMB2_READ */ cpu_to_le16(49), | |
42 | /* SMB2_WRITE */ cpu_to_le16(49), | |
43 | /* SMB2_LOCK */ cpu_to_le16(48), | |
44 | /* SMB2_IOCTL */ cpu_to_le16(57), | |
45 | /* SMB2_CANCEL */ cpu_to_le16(4), | |
46 | /* SMB2_ECHO */ cpu_to_le16(4), | |
47 | /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33), | |
48 | /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32), | |
49 | /* SMB2_QUERY_INFO */ cpu_to_le16(41), | |
50 | /* SMB2_SET_INFO */ cpu_to_le16(33), | |
51 | /* use 44 for lease break */ | |
52 | /* SMB2_OPLOCK_BREAK */ cpu_to_le16(36) | |
53 | }; | |
54 | ||
55 | /* | |
56 | * The size of the variable area depends on the offset and length fields | |
57 | * located in different fields for various SMB2 requests. SMB2 requests | |
58 | * with no variable length info, show an offset of zero for the offset field. | |
59 | */ | |
60 | static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = { | |
61 | /* SMB2_NEGOTIATE */ true, | |
62 | /* SMB2_SESSION_SETUP */ true, | |
63 | /* SMB2_LOGOFF */ false, | |
64 | /* SMB2_TREE_CONNECT */ true, | |
65 | /* SMB2_TREE_DISCONNECT */ false, | |
66 | /* SMB2_CREATE */ true, | |
67 | /* SMB2_CLOSE */ false, | |
68 | /* SMB2_FLUSH */ false, | |
69 | /* SMB2_READ */ true, | |
70 | /* SMB2_WRITE */ true, | |
71 | /* SMB2_LOCK */ true, | |
72 | /* SMB2_IOCTL */ true, | |
73 | /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */ | |
74 | /* SMB2_ECHO */ false, | |
75 | /* SMB2_QUERY_DIRECTORY */ true, | |
76 | /* SMB2_CHANGE_NOTIFY */ false, | |
77 | /* SMB2_QUERY_INFO */ true, | |
78 | /* SMB2_SET_INFO */ true, | |
79 | /* SMB2_OPLOCK_BREAK */ false | |
80 | }; | |
81 | ||
82 | /* | |
83 | * Returns the pointer to the beginning of the data area. Length of the data | |
84 | * area and the offset to it (from the beginning of the smb are also returned. | |
85 | */ | |
86 | static char *smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr) | |
87 | { | |
88 | *off = 0; | |
89 | *len = 0; | |
90 | ||
91 | /* error reqeusts do not have data area */ | |
92 | if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED && | |
64b39f4a | 93 | (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE) |
e2f34481 NJ |
94 | return NULL; |
95 | ||
96 | /* | |
97 | * Following commands have data areas so we have to get the location | |
98 | * of the data buffer offset and data buffer length for the particular | |
99 | * command. | |
100 | */ | |
101 | switch (hdr->Command) { | |
102 | case SMB2_SESSION_SETUP: | |
64b39f4a NJ |
103 | *off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset); |
104 | *len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength); | |
e2f34481 NJ |
105 | break; |
106 | case SMB2_TREE_CONNECT: | |
64b39f4a NJ |
107 | *off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset); |
108 | *len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength); | |
e2f34481 NJ |
109 | break; |
110 | case SMB2_CREATE: | |
111 | { | |
112 | if (((struct smb2_create_req *)hdr)->CreateContextsLength) { | |
113 | *off = le32_to_cpu(((struct smb2_create_req *) | |
114 | hdr)->CreateContextsOffset); | |
115 | *len = le32_to_cpu(((struct smb2_create_req *) | |
116 | hdr)->CreateContextsLength); | |
117 | break; | |
118 | } | |
119 | ||
64b39f4a NJ |
120 | *off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); |
121 | *len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); | |
e2f34481 NJ |
122 | break; |
123 | } | |
124 | case SMB2_QUERY_INFO: | |
64b39f4a NJ |
125 | *off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset); |
126 | *len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength); | |
e2f34481 NJ |
127 | break; |
128 | case SMB2_SET_INFO: | |
64b39f4a NJ |
129 | *off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset); |
130 | *len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength); | |
e2f34481 NJ |
131 | break; |
132 | case SMB2_READ: | |
64b39f4a NJ |
133 | *off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset); |
134 | *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); | |
e2f34481 NJ |
135 | break; |
136 | case SMB2_WRITE: | |
137 | if (((struct smb2_write_req *)hdr)->DataOffset) { | |
64b39f4a NJ |
138 | *off = le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset); |
139 | *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); | |
e2f34481 NJ |
140 | break; |
141 | } | |
142 | ||
64b39f4a NJ |
143 | *off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset); |
144 | *len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength); | |
e2f34481 NJ |
145 | break; |
146 | case SMB2_QUERY_DIRECTORY: | |
64b39f4a NJ |
147 | *off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset); |
148 | *len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength); | |
e2f34481 NJ |
149 | break; |
150 | case SMB2_LOCK: | |
151 | { | |
152 | int lock_count; | |
153 | ||
154 | /* | |
155 | * smb2_lock request size is 48 included single | |
156 | * smb2_lock_element structure size. | |
157 | */ | |
64b39f4a | 158 | lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount) - 1; |
e2f34481 NJ |
159 | if (lock_count > 0) { |
160 | *off = __SMB2_HEADER_STRUCTURE_SIZE + 48; | |
161 | *len = sizeof(struct smb2_lock_element) * lock_count; | |
162 | } | |
163 | break; | |
164 | } | |
165 | case SMB2_IOCTL: | |
64b39f4a | 166 | *off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset); |
e2f34481 NJ |
167 | *len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount); |
168 | ||
169 | break; | |
170 | default: | |
171 | ksmbd_debug(SMB, "no length check for command\n"); | |
172 | break; | |
173 | } | |
174 | ||
175 | /* | |
176 | * Invalid length or offset probably means data area is invalid, but | |
177 | * we have little choice but to ignore the data area in this case. | |
178 | */ | |
179 | if (*off > 4096) { | |
180 | ksmbd_debug(SMB, "offset %d too large, data area ignored\n", | |
070fb21e | 181 | *off); |
e2f34481 NJ |
182 | *len = 0; |
183 | *off = 0; | |
184 | } else if (*off < 0) { | |
185 | ksmbd_debug(SMB, | |
070fb21e NJ |
186 | "negative offset %d to data invalid ignore data area\n", |
187 | *off); | |
e2f34481 NJ |
188 | *off = 0; |
189 | *len = 0; | |
190 | } else if (*len < 0) { | |
191 | ksmbd_debug(SMB, | |
070fb21e NJ |
192 | "negative data length %d invalid, data area ignored\n", |
193 | *len); | |
e2f34481 NJ |
194 | *len = 0; |
195 | } else if (*len > 128 * 1024) { | |
196 | ksmbd_debug(SMB, "data area larger than 128K: %d\n", *len); | |
197 | *len = 0; | |
198 | } | |
199 | ||
200 | /* return pointer to beginning of data area, ie offset from SMB start */ | |
201 | if ((*off != 0) && (*len != 0)) | |
202 | return (char *)hdr + *off; | |
203 | else | |
204 | return NULL; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Calculate the size of the SMB message based on the fixed header | |
209 | * portion, the number of word parameters and the data portion of the message. | |
210 | */ | |
211 | static unsigned int smb2_calc_size(void *buf) | |
212 | { | |
213 | struct smb2_pdu *pdu = (struct smb2_pdu *)buf; | |
214 | struct smb2_hdr *hdr = &pdu->hdr; | |
215 | int offset; /* the offset from the beginning of SMB to data area */ | |
216 | int data_length; /* the length of the variable length data area */ | |
217 | /* Structure Size has already been checked to make sure it is 64 */ | |
218 | int len = le16_to_cpu(hdr->StructureSize); | |
219 | ||
220 | /* | |
221 | * StructureSize2, ie length of fixed parameter area has already | |
222 | * been checked to make sure it is the correct length. | |
223 | */ | |
224 | len += le16_to_cpu(pdu->StructureSize2); | |
225 | ||
226 | if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false) | |
227 | goto calc_size_exit; | |
228 | ||
229 | smb2_get_data_area_len(&offset, &data_length, hdr); | |
230 | ksmbd_debug(SMB, "SMB2 data length %d offset %d\n", data_length, | |
070fb21e | 231 | offset); |
e2f34481 NJ |
232 | |
233 | if (data_length > 0) { | |
234 | /* | |
235 | * Check to make sure that data area begins after fixed area, | |
236 | * Note that last byte of the fixed area is part of data area | |
237 | * for some commands, typically those with odd StructureSize, | |
238 | * so we must add one to the calculation. | |
239 | */ | |
240 | if (offset + 1 < len) | |
241 | ksmbd_debug(SMB, | |
070fb21e NJ |
242 | "data area offset %d overlaps SMB2 header %d\n", |
243 | offset + 1, len); | |
e2f34481 NJ |
244 | else |
245 | len = offset + data_length; | |
246 | } | |
247 | calc_size_exit: | |
248 | ksmbd_debug(SMB, "SMB2 len %d\n", len); | |
249 | return len; | |
250 | } | |
251 | ||
252 | static inline int smb2_query_info_req_len(struct smb2_query_info_req *h) | |
253 | { | |
254 | return le32_to_cpu(h->InputBufferLength) + | |
255 | le32_to_cpu(h->OutputBufferLength); | |
256 | } | |
257 | ||
258 | static inline int smb2_set_info_req_len(struct smb2_set_info_req *h) | |
259 | { | |
260 | return le32_to_cpu(h->BufferLength); | |
261 | } | |
262 | ||
263 | static inline int smb2_read_req_len(struct smb2_read_req *h) | |
264 | { | |
265 | return le32_to_cpu(h->Length); | |
266 | } | |
267 | ||
268 | static inline int smb2_write_req_len(struct smb2_write_req *h) | |
269 | { | |
270 | return le32_to_cpu(h->Length); | |
271 | } | |
272 | ||
273 | static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h) | |
274 | { | |
275 | return le32_to_cpu(h->OutputBufferLength); | |
276 | } | |
277 | ||
278 | static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h) | |
279 | { | |
280 | return le32_to_cpu(h->InputCount) + | |
281 | le32_to_cpu(h->OutputCount); | |
282 | } | |
283 | ||
284 | static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h) | |
285 | { | |
286 | return le32_to_cpu(h->MaxInputResponse) + | |
287 | le32_to_cpu(h->MaxOutputResponse); | |
288 | } | |
289 | ||
290 | static int smb2_validate_credit_charge(struct smb2_hdr *hdr) | |
291 | { | |
292 | int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; | |
293 | int credit_charge = le16_to_cpu(hdr->CreditCharge); | |
294 | void *__hdr = hdr; | |
295 | ||
296 | switch (hdr->Command) { | |
297 | case SMB2_QUERY_INFO: | |
298 | req_len = smb2_query_info_req_len(__hdr); | |
299 | break; | |
300 | case SMB2_SET_INFO: | |
301 | req_len = smb2_set_info_req_len(__hdr); | |
302 | break; | |
303 | case SMB2_READ: | |
304 | req_len = smb2_read_req_len(__hdr); | |
305 | break; | |
306 | case SMB2_WRITE: | |
307 | req_len = smb2_write_req_len(__hdr); | |
308 | break; | |
309 | case SMB2_QUERY_DIRECTORY: | |
310 | req_len = smb2_query_dir_req_len(__hdr); | |
311 | break; | |
312 | case SMB2_IOCTL: | |
313 | req_len = smb2_ioctl_req_len(__hdr); | |
314 | expect_resp_len = smb2_ioctl_resp_len(__hdr); | |
315 | break; | |
316 | default: | |
317 | return 0; | |
318 | } | |
319 | ||
a5a25a11 | 320 | credit_charge = max(1, credit_charge); |
e2f34481 NJ |
321 | max_len = max(req_len, expect_resp_len); |
322 | calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE); | |
a5a25a11 MM |
323 | |
324 | if (credit_charge < calc_credit_num) { | |
325 | pr_err("Insufficient credit charge, given: %d, needed: %d\n", | |
bde1694a | 326 | credit_charge, calc_credit_num); |
e2f34481 NJ |
327 | return 1; |
328 | } | |
329 | ||
330 | return 0; | |
331 | } | |
332 | ||
333 | int ksmbd_smb2_check_message(struct ksmbd_work *work) | |
334 | { | |
e5066499 | 335 | struct smb2_pdu *pdu = work->request_buf; |
e2f34481 NJ |
336 | struct smb2_hdr *hdr = &pdu->hdr; |
337 | int command; | |
338 | __u32 clc_len; /* calculated length */ | |
339 | __u32 len = get_rfc1002_len(pdu); | |
340 | ||
341 | if (work->next_smb2_rcv_hdr_off) { | |
8a893315 | 342 | pdu = ksmbd_req_buf_next(work); |
e2f34481 NJ |
343 | hdr = &pdu->hdr; |
344 | } | |
345 | ||
64b39f4a | 346 | if (le32_to_cpu(hdr->NextCommand) > 0) { |
e2f34481 | 347 | len = le32_to_cpu(hdr->NextCommand); |
64b39f4a | 348 | } else if (work->next_smb2_rcv_hdr_off) { |
e2f34481 NJ |
349 | len -= work->next_smb2_rcv_hdr_off; |
350 | len = round_up(len, 8); | |
351 | } | |
352 | ||
353 | if (check_smb2_hdr(hdr)) | |
354 | return 1; | |
355 | ||
356 | if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { | |
357 | ksmbd_debug(SMB, "Illegal structure size %u\n", | |
070fb21e | 358 | le16_to_cpu(hdr->StructureSize)); |
e2f34481 NJ |
359 | return 1; |
360 | } | |
361 | ||
362 | command = le16_to_cpu(hdr->Command); | |
363 | if (command >= NUMBER_OF_SMB2_COMMANDS) { | |
364 | ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command); | |
365 | return 1; | |
366 | } | |
367 | ||
368 | if (smb2_req_struct_sizes[command] != pdu->StructureSize2) { | |
64b39f4a NJ |
369 | if (command != SMB2_OPLOCK_BREAK_HE && |
370 | (hdr->Status == 0 || pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) { | |
e2f34481 NJ |
371 | /* error packets have 9 byte structure size */ |
372 | ksmbd_debug(SMB, | |
070fb21e NJ |
373 | "Illegal request size %u for command %d\n", |
374 | le16_to_cpu(pdu->StructureSize2), command); | |
e2f34481 | 375 | return 1; |
64b39f4a NJ |
376 | } else if (command == SMB2_OPLOCK_BREAK_HE && |
377 | hdr->Status == 0 && | |
378 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_20 && | |
379 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_21) { | |
e2f34481 NJ |
380 | /* special case for SMB2.1 lease break message */ |
381 | ksmbd_debug(SMB, | |
070fb21e NJ |
382 | "Illegal request size %d for oplock break\n", |
383 | le16_to_cpu(pdu->StructureSize2)); | |
e2f34481 NJ |
384 | return 1; |
385 | } | |
386 | } | |
387 | ||
d347d745 NJ |
388 | if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && |
389 | smb2_validate_credit_charge(hdr)) { | |
390 | work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); | |
391 | return 1; | |
392 | } | |
393 | ||
e2f34481 NJ |
394 | clc_len = smb2_calc_size(hdr); |
395 | if (len != clc_len) { | |
396 | /* server can return one byte more due to implied bcc[0] */ | |
397 | if (clc_len == len + 1) | |
398 | return 0; | |
399 | ||
400 | /* | |
401 | * Some windows servers (win2016) will pad also the final | |
402 | * PDU in a compound to 8 bytes. | |
403 | */ | |
404 | if (ALIGN(clc_len, 8) == len) | |
405 | return 0; | |
406 | ||
407 | /* | |
408 | * windows client also pad up to 8 bytes when compounding. | |
409 | * If pad is longer than eight bytes, log the server behavior | |
410 | * (once), since may indicate a problem but allow it and | |
411 | * continue since the frame is parseable. | |
412 | */ | |
413 | if (clc_len < len) { | |
414 | ksmbd_debug(SMB, | |
070fb21e NJ |
415 | "cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n", |
416 | len, clc_len, command, | |
417 | le64_to_cpu(hdr->MessageId)); | |
e2f34481 NJ |
418 | return 0; |
419 | } | |
420 | ||
421 | if (command == SMB2_LOCK_HE && len == 88) | |
422 | return 0; | |
423 | ||
424 | ksmbd_debug(SMB, | |
070fb21e NJ |
425 | "cli req too short, len %d not %d. cmd:%d mid:%llu\n", |
426 | len, clc_len, command, | |
427 | le64_to_cpu(hdr->MessageId)); | |
e2f34481 NJ |
428 | |
429 | return 1; | |
430 | } | |
431 | ||
67307023 | 432 | return 0; |
e2f34481 NJ |
433 | } |
434 | ||
435 | int smb2_negotiate_request(struct ksmbd_work *work) | |
436 | { | |
437 | return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE); | |
438 | } |