xref: /openbmc/linux/include/rdma/uverbs_ioctl.h (revision 84b102f5)
1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2 /*
3  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
4  */
5 
6 #ifndef _UVERBS_IOCTL_
7 #define _UVERBS_IOCTL_
8 
9 #include <rdma/uverbs_types.h>
10 #include <linux/uaccess.h>
11 #include <rdma/rdma_user_ioctl.h>
12 #include <rdma/ib_user_ioctl_verbs.h>
13 #include <rdma/ib_user_ioctl_cmds.h>
14 
15 /*
16  * =======================================
17  *	Verbs action specifications
18  * =======================================
19  */
20 
21 enum uverbs_attr_type {
22 	UVERBS_ATTR_TYPE_NA,
23 	UVERBS_ATTR_TYPE_PTR_IN,
24 	UVERBS_ATTR_TYPE_PTR_OUT,
25 	UVERBS_ATTR_TYPE_IDR,
26 	UVERBS_ATTR_TYPE_FD,
27 	UVERBS_ATTR_TYPE_ENUM_IN,
28 	UVERBS_ATTR_TYPE_IDRS_ARRAY,
29 };
30 
31 enum uverbs_obj_access {
32 	UVERBS_ACCESS_READ,
33 	UVERBS_ACCESS_WRITE,
34 	UVERBS_ACCESS_NEW,
35 	UVERBS_ACCESS_DESTROY
36 };
37 
38 /* Specification of a single attribute inside the ioctl message */
39 /* good size 16 */
40 struct uverbs_attr_spec {
41 	u8 type;
42 
43 	/*
44 	 * Support extending attributes by length. Allow the user to provide
45 	 * more bytes than ptr.len, but check that everything after is zero'd
46 	 * by the user.
47 	 */
48 	u8 zero_trailing:1;
49 	/*
50 	 * Valid only for PTR_IN. Allocate and copy the data inside
51 	 * the parser
52 	 */
53 	u8 alloc_and_copy:1;
54 	u8 mandatory:1;
55 	/* True if this is from UVERBS_ATTR_UHW */
56 	u8 is_udata:1;
57 
58 	union {
59 		struct {
60 			/* Current known size to kernel */
61 			u16 len;
62 			/* User isn't allowed to provide something < min_len */
63 			u16 min_len;
64 		} ptr;
65 
66 		struct {
67 			/*
68 			 * higher bits mean the namespace and lower bits mean
69 			 * the type id within the namespace.
70 			 */
71 			u16 obj_type;
72 			u8 access;
73 		} obj;
74 
75 		struct {
76 			u8 num_elems;
77 		} enum_def;
78 	} u;
79 
80 	/* This weird split lets us remove some padding */
81 	union {
82 		struct {
83 			/*
84 			 * The enum attribute can select one of the attributes
85 			 * contained in the ids array. Currently only PTR_IN
86 			 * attributes are supported in the ids array.
87 			 */
88 			const struct uverbs_attr_spec *ids;
89 		} enum_def;
90 
91 		struct {
92 			/*
93 			 * higher bits mean the namespace and lower bits mean
94 			 * the type id within the namespace.
95 			 */
96 			u16				obj_type;
97 			u16				min_len;
98 			u16				max_len;
99 			u8				access;
100 		} objs_arr;
101 	} u2;
102 };
103 
104 /*
105  * Information about the API is loaded into a radix tree. For IOCTL we start
106  * with a tuple of:
107  *  object_id, attr_id, method_id
108  *
109  * Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
110  * on the current kernel support this is compressed into 16 bit key for the
111  * radix tree. Since this compression is entirely internal to the kernel the
112  * below limits can be revised if the kernel gains additional data.
113  *
114  * With 64 leafs per node this is a 3 level radix tree.
115  *
116  * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
117  * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
118  *
119  * This also encodes the tables for the write() and write() extended commands
120  * using the coding
121  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE,command #
122  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE_EX,command_ex #
123  * ie the WRITE path is treated as a special method type in the ioctl
124  * framework.
125  */
126 enum uapi_radix_data {
127 	UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
128 
129 	UVERBS_API_ATTR_KEY_BITS = 6,
130 	UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
131 	UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
132 	UVERBS_API_WRITE_KEY_NUM = 1 << UVERBS_API_ATTR_KEY_BITS,
133 
134 	UVERBS_API_METHOD_KEY_BITS = 5,
135 	UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
136 	UVERBS_API_METHOD_KEY_NUM_CORE = 22,
137 	UVERBS_API_METHOD_IS_WRITE = 30 << UVERBS_API_METHOD_KEY_SHIFT,
138 	UVERBS_API_METHOD_IS_WRITE_EX = 31 << UVERBS_API_METHOD_KEY_SHIFT,
139 	UVERBS_API_METHOD_KEY_NUM_DRIVER =
140 		(UVERBS_API_METHOD_IS_WRITE >> UVERBS_API_METHOD_KEY_SHIFT) -
141 		UVERBS_API_METHOD_KEY_NUM_CORE,
142 	UVERBS_API_METHOD_KEY_MASK = GENMASK(
143 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
144 		UVERBS_API_METHOD_KEY_SHIFT),
145 
146 	UVERBS_API_OBJ_KEY_BITS = 5,
147 	UVERBS_API_OBJ_KEY_SHIFT =
148 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,
149 	UVERBS_API_OBJ_KEY_NUM_CORE = 20,
150 	UVERBS_API_OBJ_KEY_NUM_DRIVER =
151 		(1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
152 	UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
153 
154 	/* This id guaranteed to not exist in the radix tree */
155 	UVERBS_API_KEY_ERR = 0xFFFFFFFF,
156 };
157 
158 static inline __attribute_const__ u32 uapi_key_obj(u32 id)
159 {
160 	if (id & UVERBS_API_NS_FLAG) {
161 		id &= ~UVERBS_API_NS_FLAG;
162 		if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
163 			return UVERBS_API_KEY_ERR;
164 		id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
165 	} else {
166 		if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
167 			return UVERBS_API_KEY_ERR;
168 	}
169 
170 	return id << UVERBS_API_OBJ_KEY_SHIFT;
171 }
172 
173 static inline __attribute_const__ bool uapi_key_is_object(u32 key)
174 {
175 	return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
176 }
177 
178 static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
179 {
180 	if (id & UVERBS_API_NS_FLAG) {
181 		id &= ~UVERBS_API_NS_FLAG;
182 		if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
183 			return UVERBS_API_KEY_ERR;
184 		id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
185 	} else {
186 		id++;
187 		if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
188 			return UVERBS_API_KEY_ERR;
189 	}
190 
191 	return id << UVERBS_API_METHOD_KEY_SHIFT;
192 }
193 
194 static inline __attribute_const__ u32 uapi_key_write_method(u32 id)
195 {
196 	if (id >= UVERBS_API_WRITE_KEY_NUM)
197 		return UVERBS_API_KEY_ERR;
198 	return UVERBS_API_METHOD_IS_WRITE | id;
199 }
200 
201 static inline __attribute_const__ u32 uapi_key_write_ex_method(u32 id)
202 {
203 	if (id >= UVERBS_API_WRITE_KEY_NUM)
204 		return UVERBS_API_KEY_ERR;
205 	return UVERBS_API_METHOD_IS_WRITE_EX | id;
206 }
207 
208 static inline __attribute_const__ u32
209 uapi_key_attr_to_ioctl_method(u32 attr_key)
210 {
211 	return attr_key &
212 	       (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
213 }
214 
215 static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
216 {
217 	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
218 
219 	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
220 	       (key & UVERBS_API_ATTR_KEY_MASK) == 0;
221 }
222 
223 static inline __attribute_const__ bool uapi_key_is_write_method(u32 key)
224 {
225 	return (key & UVERBS_API_METHOD_KEY_MASK) == UVERBS_API_METHOD_IS_WRITE;
226 }
227 
228 static inline __attribute_const__ bool uapi_key_is_write_ex_method(u32 key)
229 {
230 	return (key & UVERBS_API_METHOD_KEY_MASK) ==
231 	       UVERBS_API_METHOD_IS_WRITE_EX;
232 }
233 
234 static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
235 {
236 	/* 0 is the method slot itself */
237 	return ioctl_method_key + 1;
238 }
239 
240 static inline __attribute_const__ u32 uapi_key_attr(u32 id)
241 {
242 	/*
243 	 * The attr is designed to fit in the typical single radix tree node
244 	 * of 64 entries. Since allmost all methods have driver attributes we
245 	 * organize things so that the driver and core attributes interleave to
246 	 * reduce the length of the attributes array in typical cases.
247 	 */
248 	if (id & UVERBS_API_NS_FLAG) {
249 		id &= ~UVERBS_API_NS_FLAG;
250 		id++;
251 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
252 			return UVERBS_API_KEY_ERR;
253 		id = (id << 1) | 0;
254 	} else {
255 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
256 			return UVERBS_API_KEY_ERR;
257 		id = (id << 1) | 1;
258 	}
259 
260 	return id;
261 }
262 
263 /* Only true for ioctl methods */
264 static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
265 {
266 	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
267 
268 	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
269 	       (key & UVERBS_API_ATTR_KEY_MASK) != 0;
270 }
271 
272 /*
273  * This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
274  * basically it undoes the reservation of 0 in the ID numbering. attr_key
275  * must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
276  * uapi_key_attr().
277  */
278 static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
279 {
280 	return attr_key - 1;
281 }
282 
283 static inline __attribute_const__ u32 uapi_bkey_to_key_attr(u32 attr_bkey)
284 {
285 	return attr_bkey + 1;
286 }
287 
288 /*
289  * =======================================
290  *	Verbs definitions
291  * =======================================
292  */
293 
294 struct uverbs_attr_def {
295 	u16                           id;
296 	struct uverbs_attr_spec       attr;
297 };
298 
299 struct uverbs_method_def {
300 	u16                                  id;
301 	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
302 	u32				     flags;
303 	size_t				     num_attrs;
304 	const struct uverbs_attr_def * const (*attrs)[];
305 	int (*handler)(struct uverbs_attr_bundle *attrs);
306 };
307 
308 struct uverbs_object_def {
309 	u16					 id;
310 	const struct uverbs_obj_type	        *type_attrs;
311 	size_t				         num_methods;
312 	const struct uverbs_method_def * const (*methods)[];
313 };
314 
315 enum uapi_definition_kind {
316 	UAPI_DEF_END = 0,
317 	UAPI_DEF_OBJECT_START,
318 	UAPI_DEF_WRITE,
319 	UAPI_DEF_CHAIN_OBJ_TREE,
320 	UAPI_DEF_CHAIN,
321 	UAPI_DEF_IS_SUPPORTED_FUNC,
322 	UAPI_DEF_IS_SUPPORTED_DEV_FN,
323 };
324 
325 enum uapi_definition_scope {
326 	UAPI_SCOPE_OBJECT = 1,
327 	UAPI_SCOPE_METHOD = 2,
328 };
329 
330 struct uapi_definition {
331 	u8 kind;
332 	u8 scope;
333 	union {
334 		struct {
335 			u16 object_id;
336 		} object_start;
337 		struct {
338 			u16 command_num;
339 			u8 is_ex:1;
340 			u8 has_udata:1;
341 			u8 has_resp:1;
342 			u8 req_size;
343 			u8 resp_size;
344 		} write;
345 	};
346 
347 	union {
348 		bool (*func_is_supported)(struct ib_device *device);
349 		int (*func_write)(struct uverbs_attr_bundle *attrs);
350 		const struct uapi_definition *chain;
351 		const struct uverbs_object_def *chain_obj_tree;
352 		size_t needs_fn_offset;
353 	};
354 };
355 
356 /* Define things connected to object_id */
357 #define DECLARE_UVERBS_OBJECT(_object_id, ...)                                 \
358 	{                                                                      \
359 		.kind = UAPI_DEF_OBJECT_START,                                 \
360 		.object_start = { .object_id = _object_id },                   \
361 	},                                                                     \
362 		##__VA_ARGS__
363 
364 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
365 #define DECLARE_UVERBS_WRITE(_command_num, _func, _cmd_desc, ...)              \
366 	{                                                                      \
367 		.kind = UAPI_DEF_WRITE,                                        \
368 		.scope = UAPI_SCOPE_OBJECT,                                    \
369 		.write = { .is_ex = 0, .command_num = _command_num },          \
370 		.func_write = _func,                                           \
371 		_cmd_desc,                                                     \
372 	},                                                                     \
373 		##__VA_ARGS__
374 
375 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
376 #define DECLARE_UVERBS_WRITE_EX(_command_num, _func, _cmd_desc, ...)           \
377 	{                                                                      \
378 		.kind = UAPI_DEF_WRITE,                                        \
379 		.scope = UAPI_SCOPE_OBJECT,                                    \
380 		.write = { .is_ex = 1, .command_num = _command_num },          \
381 		.func_write = _func,                                           \
382 		_cmd_desc,                                                     \
383 	},                                                                     \
384 		##__VA_ARGS__
385 
386 /*
387  * Object is only supported if the function pointer named ibdev_fn in struct
388  * ib_device is not NULL.
389  */
390 #define UAPI_DEF_OBJ_NEEDS_FN(ibdev_fn)                                        \
391 	{                                                                      \
392 		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
393 		.scope = UAPI_SCOPE_OBJECT,                                    \
394 		.needs_fn_offset =                                             \
395 			offsetof(struct ib_device_ops, ibdev_fn) +             \
396 			BUILD_BUG_ON_ZERO(sizeof_field(struct ib_device_ops,   \
397 						       ibdev_fn) !=            \
398 					  sizeof(void *)),                     \
399 	}
400 
401 /*
402  * Method is only supported if the function pointer named ibdev_fn in struct
403  * ib_device is not NULL.
404  */
405 #define UAPI_DEF_METHOD_NEEDS_FN(ibdev_fn)                                     \
406 	{                                                                      \
407 		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
408 		.scope = UAPI_SCOPE_METHOD,                                    \
409 		.needs_fn_offset =                                             \
410 			offsetof(struct ib_device_ops, ibdev_fn) +             \
411 			BUILD_BUG_ON_ZERO(sizeof_field(struct ib_device_ops,   \
412 						       ibdev_fn) !=            \
413 					  sizeof(void *)),                     \
414 	}
415 
416 /* Call a function to determine if the entire object is supported or not */
417 #define UAPI_DEF_IS_OBJ_SUPPORTED(_func)                                       \
418 	{                                                                      \
419 		.kind = UAPI_DEF_IS_SUPPORTED_FUNC,                            \
420 		.scope = UAPI_SCOPE_OBJECT, .func_is_supported = _func,        \
421 	}
422 
423 /* Include another struct uapi_definition in this one */
424 #define UAPI_DEF_CHAIN(_def_var)                                               \
425 	{                                                                      \
426 		.kind = UAPI_DEF_CHAIN, .chain = _def_var,                     \
427 	}
428 
429 /* Temporary until the tree base description is replaced */
430 #define UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, _object_ptr, ...)                \
431 	{                                                                      \
432 		.kind = UAPI_DEF_CHAIN_OBJ_TREE,                               \
433 		.object_start = { .object_id = _object_enum },                 \
434 		.chain_obj_tree = _object_ptr,                                 \
435 	},								       \
436 		##__VA_ARGS__
437 #define UAPI_DEF_CHAIN_OBJ_TREE_NAMED(_object_enum, ...)                       \
438 	UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, &UVERBS_OBJECT(_object_enum),    \
439 				##__VA_ARGS__)
440 
441 /*
442  * =======================================
443  *	Attribute Specifications
444  * =======================================
445  */
446 
447 #define UVERBS_ATTR_SIZE(_min_len, _len)			\
448 	.u.ptr.min_len = _min_len, .u.ptr.len = _len
449 
450 #define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)
451 
452 /*
453  * Specifies a uapi structure that cannot be extended. The user must always
454  * supply the whole structure and nothing more. The structure must be declared
455  * in a header under include/uapi/rdma.
456  */
457 #define UVERBS_ATTR_TYPE(_type)					\
458 	.u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
459 /*
460  * Specifies a uapi structure where the user must provide at least up to
461  * member 'last'.  Anything after last and up until the end of the structure
462  * can be non-zero, anything longer than the end of the structure must be
463  * zero. The structure must be declared in a header under include/uapi/rdma.
464  */
465 #define UVERBS_ATTR_STRUCT(_type, _last)                                       \
466 	.zero_trailing = 1,                                                    \
467 	UVERBS_ATTR_SIZE(offsetofend(_type, _last), sizeof(_type))
468 /*
469  * Specifies at least min_len bytes must be passed in, but the amount can be
470  * larger, up to the protocol maximum size. No check for zeroing is done.
471  */
472 #define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)
473 
474 /* Must be used in the '...' of any UVERBS_ATTR */
475 #define UA_ALLOC_AND_COPY .alloc_and_copy = 1
476 #define UA_MANDATORY .mandatory = 1
477 #define UA_OPTIONAL .mandatory = 0
478 
479 /*
480  * min_len must be bigger than 0 and _max_len must be smaller than 4095.  Only
481  * READ\WRITE accesses are supported.
482  */
483 #define UVERBS_ATTR_IDRS_ARR(_attr_id, _idr_type, _access, _min_len, _max_len, \
484 			     ...)                                              \
485 	(&(const struct uverbs_attr_def){                                      \
486 		.id = (_attr_id) +                                             \
487 		      BUILD_BUG_ON_ZERO((_min_len) == 0 ||                     \
488 					(_max_len) >                           \
489 						PAGE_SIZE / sizeof(void *) ||  \
490 					(_min_len) > (_max_len) ||             \
491 					(_access) == UVERBS_ACCESS_NEW ||      \
492 					(_access) == UVERBS_ACCESS_DESTROY),   \
493 		.attr = { .type = UVERBS_ATTR_TYPE_IDRS_ARRAY,                 \
494 			  .u2.objs_arr.obj_type = _idr_type,                   \
495 			  .u2.objs_arr.access = _access,                       \
496 			  .u2.objs_arr.min_len = _min_len,                     \
497 			  .u2.objs_arr.max_len = _max_len,                     \
498 			  __VA_ARGS__ } })
499 
500 /*
501  * Only for use with UVERBS_ATTR_IDR, allows any uobject type to be accepted,
502  * the user must validate the type of the uobject instead.
503  */
504 #define UVERBS_IDR_ANY_OBJECT 0xFFFF
505 
506 #define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...)                     \
507 	(&(const struct uverbs_attr_def){                                      \
508 		.id = _attr_id,                                                \
509 		.attr = { .type = UVERBS_ATTR_TYPE_IDR,                        \
510 			  .u.obj.obj_type = _idr_type,                         \
511 			  .u.obj.access = _access,                             \
512 			  __VA_ARGS__ } })
513 
514 #define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...)                       \
515 	(&(const struct uverbs_attr_def){                                      \
516 		.id = (_attr_id) +                                             \
517 		      BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW &&      \
518 					(_access) != UVERBS_ACCESS_READ),      \
519 		.attr = { .type = UVERBS_ATTR_TYPE_FD,                         \
520 			  .u.obj.obj_type = _fd_type,                          \
521 			  .u.obj.access = _access,                             \
522 			  __VA_ARGS__ } })
523 
524 #define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...)                               \
525 	(&(const struct uverbs_attr_def){                                      \
526 		.id = _attr_id,                                                \
527 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_IN,                     \
528 			  _type,                                               \
529 			  __VA_ARGS__ } })
530 
531 #define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...)                              \
532 	(&(const struct uverbs_attr_def){                                      \
533 		.id = _attr_id,                                                \
534 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT,                    \
535 			  _type,                                               \
536 			  __VA_ARGS__ } })
537 
538 /* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
539 #define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...)                          \
540 	(&(const struct uverbs_attr_def){                                      \
541 		.id = _attr_id,                                                \
542 		.attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN,                    \
543 			  .u2.enum_def.ids = _enum_arr,                        \
544 			  .u.enum_def.num_elems = ARRAY_SIZE(_enum_arr),       \
545 			  __VA_ARGS__ },                                       \
546 	})
547 
548 /* An input value that is a member in the enum _enum_type. */
549 #define UVERBS_ATTR_CONST_IN(_attr_id, _enum_type, ...)                        \
550 	UVERBS_ATTR_PTR_IN(                                                    \
551 		_attr_id,                                                      \
552 		UVERBS_ATTR_SIZE(                                              \
553 			sizeof(u64) + BUILD_BUG_ON_ZERO(!sizeof(_enum_type)),  \
554 			sizeof(u64)),                                          \
555 		__VA_ARGS__)
556 
557 /*
558  * An input value that is a bitwise combination of values of _enum_type.
559  * This permits the flag value to be passed as either a u32 or u64, it must
560  * be retrieved via uverbs_get_flag().
561  */
562 #define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...)                        \
563 	UVERBS_ATTR_PTR_IN(                                                    \
564 		_attr_id,                                                      \
565 		UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO(              \
566 						       !sizeof(_enum_type *)), \
567 				 sizeof(u64)),                                 \
568 		__VA_ARGS__)
569 
570 /*
571  * This spec is used in order to pass information to the hardware driver in a
572  * legacy way. Every verb that could get driver specific data should get this
573  * spec.
574  */
575 #define UVERBS_ATTR_UHW()                                                      \
576 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN,                                 \
577 			   UVERBS_ATTR_MIN_SIZE(0),			       \
578 			   UA_OPTIONAL,                                        \
579 			   .is_udata = 1),				       \
580 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT,                               \
581 			    UVERBS_ATTR_MIN_SIZE(0),			       \
582 			    UA_OPTIONAL,                                       \
583 			    .is_udata = 1)
584 
585 /* =================================================
586  *              Parsing infrastructure
587  * =================================================
588  */
589 
590 
591 struct uverbs_ptr_attr {
592 	/*
593 	 * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
594 	 * used.
595 	 */
596 	union {
597 		void *ptr;
598 		u64 data;
599 	};
600 	u16		len;
601 	u16		uattr_idx;
602 	u8		enum_id;
603 };
604 
605 struct uverbs_obj_attr {
606 	struct ib_uobject		*uobject;
607 	const struct uverbs_api_attr	*attr_elm;
608 };
609 
610 struct uverbs_objs_arr_attr {
611 	struct ib_uobject **uobjects;
612 	u16 len;
613 };
614 
615 struct uverbs_attr {
616 	union {
617 		struct uverbs_ptr_attr	ptr_attr;
618 		struct uverbs_obj_attr	obj_attr;
619 		struct uverbs_objs_arr_attr objs_arr_attr;
620 	};
621 };
622 
623 struct uverbs_attr_bundle {
624 	struct ib_udata driver_udata;
625 	struct ib_udata ucore;
626 	struct ib_uverbs_file *ufile;
627 	struct ib_ucontext *context;
628 	struct ib_uobject *uobject;
629 	DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
630 	struct uverbs_attr attrs[];
631 };
632 
633 static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
634 					unsigned int idx)
635 {
636 	return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
637 			attrs_bundle->attr_present);
638 }
639 
640 /**
641  * rdma_udata_to_drv_context - Helper macro to get the driver's context out of
642  *                             ib_udata which is embedded in uverbs_attr_bundle.
643  *
644  * If udata is not NULL this cannot fail. Otherwise a NULL udata will result
645  * in a NULL ucontext pointer, as a safety precaution. Callers should be using
646  * 'udata' to determine if the driver call is in user or kernel mode, not
647  * 'ucontext'.
648  *
649  */
650 static inline struct uverbs_attr_bundle *
651 rdma_udata_to_uverbs_attr_bundle(struct ib_udata *udata)
652 {
653 	return container_of(udata, struct uverbs_attr_bundle, driver_udata);
654 }
655 
656 #define rdma_udata_to_drv_context(udata, drv_dev_struct, member)                \
657 	(udata ? container_of(rdma_udata_to_uverbs_attr_bundle(udata)->context, \
658 			      drv_dev_struct, member) : (drv_dev_struct *)NULL)
659 
660 #define IS_UVERBS_COPY_ERR(_ret)		((_ret) && (_ret) != -ENOENT)
661 
662 static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
663 							u16 idx)
664 {
665 	if (!uverbs_attr_is_valid(attrs_bundle, idx))
666 		return ERR_PTR(-ENOENT);
667 
668 	return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];
669 }
670 
671 static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
672 					  u16 idx)
673 {
674 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
675 
676 	if (IS_ERR(attr))
677 		return PTR_ERR(attr);
678 
679 	return attr->ptr_attr.enum_id;
680 }
681 
682 static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
683 					u16 idx)
684 {
685 	const struct uverbs_attr *attr;
686 
687 	attr = uverbs_attr_get(attrs_bundle, idx);
688 	if (IS_ERR(attr))
689 		return ERR_CAST(attr);
690 
691 	return attr->obj_attr.uobject->object;
692 }
693 
694 static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
695 							 u16 idx)
696 {
697 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
698 
699 	if (IS_ERR(attr))
700 		return ERR_CAST(attr);
701 
702 	return attr->obj_attr.uobject;
703 }
704 
705 static inline int
706 uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
707 {
708 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
709 
710 	if (IS_ERR(attr))
711 		return PTR_ERR(attr);
712 
713 	return attr->ptr_attr.len;
714 }
715 
716 void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *attrs_bundle,
717 				 u16 idx);
718 
719 /*
720  * uverbs_attr_ptr_get_array_size() - Get array size pointer by a ptr
721  * attribute.
722  * @attrs: The attribute bundle
723  * @idx: The ID of the attribute
724  * @elem_size: The size of the element in the array
725  */
726 static inline int
727 uverbs_attr_ptr_get_array_size(struct uverbs_attr_bundle *attrs, u16 idx,
728 			       size_t elem_size)
729 {
730 	int size = uverbs_attr_get_len(attrs, idx);
731 
732 	if (size < 0)
733 		return size;
734 
735 	if (size % elem_size)
736 		return -EINVAL;
737 
738 	return size / elem_size;
739 }
740 
741 /**
742  * uverbs_attr_get_uobjs_arr() - Provides array's properties for attribute for
743  * UVERBS_ATTR_TYPE_IDRS_ARRAY.
744  * @arr: Returned pointer to array of pointers for uobjects or NULL if
745  *       the attribute isn't provided.
746  *
747  * Return: The array length or 0 if no attribute was provided.
748  */
749 static inline int uverbs_attr_get_uobjs_arr(
750 	const struct uverbs_attr_bundle *attrs_bundle, u16 attr_idx,
751 	struct ib_uobject ***arr)
752 {
753 	const struct uverbs_attr *attr =
754 			uverbs_attr_get(attrs_bundle, attr_idx);
755 
756 	if (IS_ERR(attr)) {
757 		*arr = NULL;
758 		return 0;
759 	}
760 
761 	*arr = attr->objs_arr_attr.uobjects;
762 
763 	return attr->objs_arr_attr.len;
764 }
765 
766 static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
767 {
768 	return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
769 }
770 
771 static inline void *uverbs_attr_get_alloced_ptr(
772 	const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
773 {
774 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
775 
776 	if (IS_ERR(attr))
777 		return (void *)attr;
778 
779 	return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
780 						 attr->ptr_attr.ptr;
781 }
782 
783 static inline int _uverbs_copy_from(void *to,
784 				    const struct uverbs_attr_bundle *attrs_bundle,
785 				    size_t idx,
786 				    size_t size)
787 {
788 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
789 
790 	if (IS_ERR(attr))
791 		return PTR_ERR(attr);
792 
793 	/*
794 	 * Validation ensures attr->ptr_attr.len >= size. If the caller is
795 	 * using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
796 	 * uverbs_copy_from_or_zero.
797 	 */
798 	if (unlikely(size < attr->ptr_attr.len))
799 		return -EINVAL;
800 
801 	if (uverbs_attr_ptr_is_inline(attr))
802 		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
803 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
804 				attr->ptr_attr.len))
805 		return -EFAULT;
806 
807 	return 0;
808 }
809 
810 static inline int _uverbs_copy_from_or_zero(void *to,
811 					    const struct uverbs_attr_bundle *attrs_bundle,
812 					    size_t idx,
813 					    size_t size)
814 {
815 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
816 	size_t min_size;
817 
818 	if (IS_ERR(attr))
819 		return PTR_ERR(attr);
820 
821 	min_size = min_t(size_t, size, attr->ptr_attr.len);
822 
823 	if (uverbs_attr_ptr_is_inline(attr))
824 		memcpy(to, &attr->ptr_attr.data, min_size);
825 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
826 				min_size))
827 		return -EFAULT;
828 
829 	if (size > min_size)
830 		memset(to + min_size, 0, size - min_size);
831 
832 	return 0;
833 }
834 
835 #define uverbs_copy_from(to, attrs_bundle, idx)				      \
836 	_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
837 
838 #define uverbs_copy_from_or_zero(to, attrs_bundle, idx)			      \
839 	_uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))
840 
841 static inline struct ib_ucontext *
842 ib_uverbs_get_ucontext(const struct uverbs_attr_bundle *attrs)
843 {
844 	return ib_uverbs_get_ucontext_file(attrs->ufile);
845 }
846 
847 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
848 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
849 		       size_t idx, u64 allowed_bits);
850 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
851 		       size_t idx, u64 allowed_bits);
852 int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
853 		   const void *from, size_t size);
854 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
855 			     gfp_t flags);
856 
857 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
858 					  size_t size)
859 {
860 	return _uverbs_alloc(bundle, size, GFP_KERNEL);
861 }
862 
863 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
864 					   size_t size)
865 {
866 	return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
867 }
868 
869 static inline __malloc void *uverbs_kcalloc(struct uverbs_attr_bundle *bundle,
870 					    size_t n, size_t size)
871 {
872 	size_t bytes;
873 
874 	if (unlikely(check_mul_overflow(n, size, &bytes)))
875 		return ERR_PTR(-EOVERFLOW);
876 	return uverbs_zalloc(bundle, bytes);
877 }
878 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
879 		      size_t idx, s64 lower_bound, u64 upper_bound,
880 		      s64 *def_val);
881 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
882 				  size_t idx, const void *from, size_t size);
883 #else
884 static inline int
885 uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
886 		   size_t idx, u64 allowed_bits)
887 {
888 	return -EINVAL;
889 }
890 static inline int
891 uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
892 		   size_t idx, u64 allowed_bits)
893 {
894 	return -EINVAL;
895 }
896 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
897 				 size_t idx, const void *from, size_t size)
898 {
899 	return -EINVAL;
900 }
901 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
902 					  size_t size)
903 {
904 	return ERR_PTR(-EINVAL);
905 }
906 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
907 					   size_t size)
908 {
909 	return ERR_PTR(-EINVAL);
910 }
911 static inline int
912 _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
913 		  size_t idx, s64 lower_bound, u64 upper_bound,
914 		  s64 *def_val)
915 {
916 	return -EINVAL;
917 }
918 static inline int
919 uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
920 			      size_t idx, const void *from, size_t size)
921 {
922 	return -EINVAL;
923 }
924 #endif
925 
926 #define uverbs_get_const(_to, _attrs_bundle, _idx)                             \
927 	({                                                                     \
928 		s64 _val;                                                      \
929 		int _ret = _uverbs_get_const(&_val, _attrs_bundle, _idx,       \
930 					     type_min(typeof(*_to)),           \
931 					     type_max(typeof(*_to)), NULL);    \
932 		(*_to) = _val;                                                 \
933 		_ret;                                                          \
934 	})
935 
936 #define uverbs_get_const_default(_to, _attrs_bundle, _idx, _default)           \
937 	({                                                                     \
938 		s64 _val;                                                      \
939 		s64 _def_val = _default;                                       \
940 		int _ret =                                                     \
941 			_uverbs_get_const(&_val, _attrs_bundle, _idx,          \
942 					  type_min(typeof(*_to)),              \
943 					  type_max(typeof(*_to)), &_def_val);  \
944 		(*_to) = _val;                                                 \
945 		_ret;                                                          \
946 	})
947 #endif
948