xref: /openbmc/linux/include/rdma/uverbs_ioctl.h (revision e3b9f1e8)
1 /*
2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #ifndef _UVERBS_IOCTL_
34 #define _UVERBS_IOCTL_
35 
36 #include <rdma/uverbs_types.h>
37 #include <linux/uaccess.h>
38 #include <rdma/rdma_user_ioctl.h>
39 #include <rdma/ib_user_ioctl_verbs.h>
40 
41 /*
42  * =======================================
43  *	Verbs action specifications
44  * =======================================
45  */
46 
47 enum uverbs_attr_type {
48 	UVERBS_ATTR_TYPE_NA,
49 	UVERBS_ATTR_TYPE_PTR_IN,
50 	UVERBS_ATTR_TYPE_PTR_OUT,
51 	UVERBS_ATTR_TYPE_IDR,
52 	UVERBS_ATTR_TYPE_FD,
53 };
54 
55 enum uverbs_obj_access {
56 	UVERBS_ACCESS_READ,
57 	UVERBS_ACCESS_WRITE,
58 	UVERBS_ACCESS_NEW,
59 	UVERBS_ACCESS_DESTROY
60 };
61 
62 enum {
63 	UVERBS_ATTR_SPEC_F_MANDATORY	= 1U << 0,
64 	/* Support extending attributes by length */
65 	UVERBS_ATTR_SPEC_F_MIN_SZ	= 1U << 1,
66 };
67 
68 struct uverbs_attr_spec {
69 	enum uverbs_attr_type		type;
70 	union {
71 		u16				len;
72 		struct {
73 			/*
74 			 * higher bits mean the namespace and lower bits mean
75 			 * the type id within the namespace.
76 			 */
77 			u16			obj_type;
78 			u8			access;
79 		} obj;
80 	};
81 	/* Combination of bits from enum UVERBS_ATTR_SPEC_F_XXXX */
82 	u8				flags;
83 };
84 
85 struct uverbs_attr_spec_hash {
86 	size_t				num_attrs;
87 	unsigned long			*mandatory_attrs_bitmask;
88 	struct uverbs_attr_spec		attrs[0];
89 };
90 
91 struct uverbs_attr_bundle;
92 struct ib_uverbs_file;
93 
94 enum {
95 	/*
96 	 * Action marked with this flag creates a context (or root for all
97 	 * objects).
98 	 */
99 	UVERBS_ACTION_FLAG_CREATE_ROOT = 1U << 0,
100 };
101 
102 struct uverbs_method_spec {
103 	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
104 	u32						flags;
105 	size_t						num_buckets;
106 	size_t						num_child_attrs;
107 	int (*handler)(struct ib_device *ib_dev, struct ib_uverbs_file *ufile,
108 		       struct uverbs_attr_bundle *ctx);
109 	struct uverbs_attr_spec_hash		*attr_buckets[0];
110 };
111 
112 struct uverbs_method_spec_hash {
113 	size_t					num_methods;
114 	struct uverbs_method_spec		*methods[0];
115 };
116 
117 struct uverbs_object_spec {
118 	const struct uverbs_obj_type		*type_attrs;
119 	size_t					num_buckets;
120 	struct uverbs_method_spec_hash		*method_buckets[0];
121 };
122 
123 struct uverbs_object_spec_hash {
124 	size_t					num_objects;
125 	struct uverbs_object_spec		*objects[0];
126 };
127 
128 struct uverbs_root_spec {
129 	size_t					num_buckets;
130 	struct uverbs_object_spec_hash		*object_buckets[0];
131 };
132 
133 /*
134  * =======================================
135  *	Verbs definitions
136  * =======================================
137  */
138 
139 struct uverbs_attr_def {
140 	u16                           id;
141 	struct uverbs_attr_spec       attr;
142 };
143 
144 struct uverbs_method_def {
145 	u16                                  id;
146 	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
147 	u32				     flags;
148 	size_t				     num_attrs;
149 	const struct uverbs_attr_def * const (*attrs)[];
150 	int (*handler)(struct ib_device *ib_dev, struct ib_uverbs_file *ufile,
151 		       struct uverbs_attr_bundle *ctx);
152 };
153 
154 struct uverbs_object_def {
155 	u16					 id;
156 	const struct uverbs_obj_type	        *type_attrs;
157 	size_t				         num_methods;
158 	const struct uverbs_method_def * const (*methods)[];
159 };
160 
161 struct uverbs_object_tree_def {
162 	size_t					 num_objects;
163 	const struct uverbs_object_def * const (*objects)[];
164 };
165 
166 #define UA_FLAGS(_flags)  .flags = _flags
167 #define __UVERBS_ATTR0(_id, _len, _type, ...)                           \
168 	((const struct uverbs_attr_def)				  \
169 	 {.id = _id, .attr = {.type = _type, {.len = _len}, .flags = 0, } })
170 #define __UVERBS_ATTR1(_id, _len, _type, _flags)                        \
171 	((const struct uverbs_attr_def)				  \
172 	 {.id = _id, .attr = {.type = _type, {.len = _len}, _flags, } })
173 #define __UVERBS_ATTR(_id, _len, _type, _flags, _n, ...)		\
174 	__UVERBS_ATTR##_n(_id, _len, _type, _flags)
175 /*
176  * In new compiler, UVERBS_ATTR could be simplified by declaring it as
177  * [_id] = {.type = _type, .len = _len, ##__VA_ARGS__}
178  * But since we support older compilers too, we need the more complex code.
179  */
180 #define UVERBS_ATTR(_id, _len, _type, ...)				\
181 	__UVERBS_ATTR(_id, _len, _type, ##__VA_ARGS__, 1, 0)
182 #define UVERBS_ATTR_PTR_IN_SZ(_id, _len, ...)				\
183 	UVERBS_ATTR(_id, _len, UVERBS_ATTR_TYPE_PTR_IN, ##__VA_ARGS__)
184 /* If sizeof(_type) <= sizeof(u64), this will be inlined rather than a pointer */
185 #define UVERBS_ATTR_PTR_IN(_id, _type, ...)				\
186 	UVERBS_ATTR_PTR_IN_SZ(_id, sizeof(_type), ##__VA_ARGS__)
187 #define UVERBS_ATTR_PTR_OUT_SZ(_id, _len, ...)				\
188 	UVERBS_ATTR(_id, _len, UVERBS_ATTR_TYPE_PTR_OUT, ##__VA_ARGS__)
189 #define UVERBS_ATTR_PTR_OUT(_id, _type, ...)				\
190 	UVERBS_ATTR_PTR_OUT_SZ(_id, sizeof(_type), ##__VA_ARGS__)
191 
192 /*
193  * In new compiler, UVERBS_ATTR_IDR (and FD) could be simplified by declaring
194  * it as
195  * {.id = _id,								\
196  *  .attr {.type = __obj_class,						\
197  *         .obj = {.obj_type = _idr_type,				\
198  *                       .access = _access                              \
199  *                }, ##__VA_ARGS__ } }
200  * But since we support older compilers too, we need the more complex code.
201  */
202 #define ___UVERBS_ATTR_OBJ0(_id, _obj_class, _obj_type, _access, ...)\
203 	((const struct uverbs_attr_def)					\
204 	{.id = _id,							\
205 	 .attr = {.type = _obj_class,					\
206 		  {.obj = {.obj_type = _obj_type, .access = _access } },\
207 		  .flags = 0} })
208 #define ___UVERBS_ATTR_OBJ1(_id, _obj_class, _obj_type, _access, _flags)\
209 	((const struct uverbs_attr_def)					\
210 	{.id = _id,							\
211 	.attr = {.type = _obj_class,					\
212 		 {.obj = {.obj_type = _obj_type, .access = _access} },	\
213 		  _flags} })
214 #define ___UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access, _flags, \
215 			   _n, ...)					\
216 	___UVERBS_ATTR_OBJ##_n(_id, _obj_class, _obj_type, _access, _flags)
217 #define __UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access, ...)	\
218 	___UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access,		\
219 			   ##__VA_ARGS__, 1, 0)
220 #define UVERBS_ATTR_IDR(_id, _idr_type, _access, ...)			 \
221 	__UVERBS_ATTR_OBJ(_id, UVERBS_ATTR_TYPE_IDR, _idr_type, _access,\
222 			  ##__VA_ARGS__)
223 #define UVERBS_ATTR_FD(_id, _fd_type, _access, ...)			\
224 	__UVERBS_ATTR_OBJ(_id, UVERBS_ATTR_TYPE_FD, _fd_type,		\
225 			  (_access) + BUILD_BUG_ON_ZERO(		\
226 				(_access) != UVERBS_ACCESS_NEW &&	\
227 				(_access) != UVERBS_ACCESS_READ),	\
228 			  ##__VA_ARGS__)
229 #define DECLARE_UVERBS_ATTR_SPEC(_name, ...)				\
230 	const struct uverbs_attr_def _name = __VA_ARGS__
231 
232 #define _UVERBS_METHOD_ATTRS_SZ(...)					\
233 	(sizeof((const struct uverbs_attr_def * const []){__VA_ARGS__}) /\
234 	 sizeof(const struct uverbs_attr_def *))
235 #define _UVERBS_METHOD(_id, _handler, _flags, ...)			\
236 	((const struct uverbs_method_def) {				\
237 	 .id = _id,							\
238 	 .flags = _flags,						\
239 	 .handler = _handler,						\
240 	 .num_attrs = _UVERBS_METHOD_ATTRS_SZ(__VA_ARGS__),		\
241 	 .attrs = &(const struct uverbs_attr_def * const []){__VA_ARGS__} })
242 #define DECLARE_UVERBS_METHOD(_name, _id, _handler, ...)		\
243 	const struct uverbs_method_def _name =				\
244 		_UVERBS_METHOD(_id, _handler, 0, ##__VA_ARGS__)
245 #define DECLARE_UVERBS_CTX_METHOD(_name, _id, _handler, _flags, ...)	\
246 	const struct uverbs_method_def _name =				\
247 		_UVERBS_METHOD(_id, _handler,				\
248 			       UVERBS_ACTION_FLAG_CREATE_ROOT,		\
249 			       ##__VA_ARGS__)
250 #define _UVERBS_OBJECT_METHODS_SZ(...)					\
251 	(sizeof((const struct uverbs_method_def * const []){__VA_ARGS__}) / \
252 	 sizeof(const struct uverbs_method_def *))
253 #define _UVERBS_OBJECT(_id, _type_attrs, ...)				\
254 	((const struct uverbs_object_def) {				\
255 	 .id = _id,							\
256 	 .type_attrs = _type_attrs,					\
257 	 .num_methods = _UVERBS_OBJECT_METHODS_SZ(__VA_ARGS__),		\
258 	 .methods = &(const struct uverbs_method_def * const []){__VA_ARGS__} })
259 #define DECLARE_UVERBS_OBJECT(_name, _id, _type_attrs, ...)		\
260 	const struct uverbs_object_def _name =				\
261 		_UVERBS_OBJECT(_id, _type_attrs, ##__VA_ARGS__)
262 #define _UVERBS_TREE_OBJECTS_SZ(...)					\
263 	(sizeof((const struct uverbs_object_def * const []){__VA_ARGS__}) / \
264 	 sizeof(const struct uverbs_object_def *))
265 #define _UVERBS_OBJECT_TREE(...)					\
266 	((const struct uverbs_object_tree_def) {			\
267 	 .num_objects = _UVERBS_TREE_OBJECTS_SZ(__VA_ARGS__),		\
268 	 .objects = &(const struct uverbs_object_def * const []){__VA_ARGS__} })
269 #define DECLARE_UVERBS_OBJECT_TREE(_name, ...)				\
270 	const struct uverbs_object_tree_def _name =			\
271 		_UVERBS_OBJECT_TREE(__VA_ARGS__)
272 
273 /* =================================================
274  *              Parsing infrastructure
275  * =================================================
276  */
277 
278 struct uverbs_ptr_attr {
279 	u64		data;
280 	u16		len;
281 	/* Combination of bits from enum UVERBS_ATTR_F_XXXX */
282 	u16		flags;
283 };
284 
285 struct uverbs_obj_attr {
286 	/* pointer to the kernel descriptor -> type, access, etc */
287 	const struct uverbs_obj_type	*type;
288 	struct ib_uobject		*uobject;
289 	/* fd or id in idr of this object */
290 	int				id;
291 };
292 
293 struct uverbs_attr {
294 	/*
295 	 * pointer to the user-space given attribute, in order to write the
296 	 * new uobject's id or update flags.
297 	 */
298 	struct ib_uverbs_attr __user	*uattr;
299 	union {
300 		struct uverbs_ptr_attr	ptr_attr;
301 		struct uverbs_obj_attr	obj_attr;
302 	};
303 };
304 
305 struct uverbs_attr_bundle_hash {
306 	/* if bit i is set, it means attrs[i] contains valid information */
307 	unsigned long *valid_bitmap;
308 	size_t num_attrs;
309 	/*
310 	 * arrays of attributes, each element corresponds to the specification
311 	 * of the attribute in the same index.
312 	 */
313 	struct uverbs_attr *attrs;
314 };
315 
316 struct uverbs_attr_bundle {
317 	size_t				num_buckets;
318 	struct uverbs_attr_bundle_hash  hash[];
319 };
320 
321 static inline bool uverbs_attr_is_valid_in_hash(const struct uverbs_attr_bundle_hash *attrs_hash,
322 						unsigned int idx)
323 {
324 	return test_bit(idx, attrs_hash->valid_bitmap);
325 }
326 
327 static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
328 					unsigned int idx)
329 {
330 	u16 idx_bucket = idx >>	UVERBS_ID_NS_SHIFT;
331 
332 	if (attrs_bundle->num_buckets <= idx_bucket)
333 		return false;
334 
335 	return uverbs_attr_is_valid_in_hash(&attrs_bundle->hash[idx_bucket],
336 					    idx & ~UVERBS_ID_NS_MASK);
337 }
338 
339 static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
340 							u16 idx)
341 {
342 	u16 idx_bucket = idx >>	UVERBS_ID_NS_SHIFT;
343 
344 	if (!uverbs_attr_is_valid(attrs_bundle, idx))
345 		return ERR_PTR(-ENOENT);
346 
347 	return &attrs_bundle->hash[idx_bucket].attrs[idx & ~UVERBS_ID_NS_MASK];
348 }
349 
350 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
351 				 size_t idx, const void *from, size_t size)
352 {
353 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
354 	u16 flags;
355 	size_t min_size;
356 
357 	if (IS_ERR(attr))
358 		return PTR_ERR(attr);
359 
360 	min_size = min_t(size_t, attr->ptr_attr.len, size);
361 	if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
362 		return -EFAULT;
363 
364 	flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
365 	if (put_user(flags, &attr->uattr->flags))
366 		return -EFAULT;
367 
368 	return 0;
369 }
370 
371 static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
372 {
373 	return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
374 }
375 
376 static inline int _uverbs_copy_from(void *to,
377 				    const struct uverbs_attr_bundle *attrs_bundle,
378 				    size_t idx,
379 				    size_t size)
380 {
381 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
382 
383 	if (IS_ERR(attr))
384 		return PTR_ERR(attr);
385 
386 	/*
387 	 * Validation ensures attr->ptr_attr.len >= size. If the caller is
388 	 * using UVERBS_ATTR_SPEC_F_MIN_SZ then it must call copy_from with
389 	 * the right size.
390 	 */
391 	if (unlikely(size < attr->ptr_attr.len))
392 		return -EINVAL;
393 
394 	if (uverbs_attr_ptr_is_inline(attr))
395 		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
396 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
397 				attr->ptr_attr.len))
398 		return -EFAULT;
399 
400 	return 0;
401 }
402 
403 #define uverbs_copy_from(to, attrs_bundle, idx)				      \
404 	_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
405 
406 /* =================================================
407  *	 Definitions -> Specs infrastructure
408  * =================================================
409  */
410 
411 /*
412  * uverbs_alloc_spec_tree - Merges different common and driver specific feature
413  *	into one parsing tree that every uverbs command will be parsed upon.
414  *
415  * @num_trees: Number of trees in the array @trees.
416  * @trees: Array of pointers to tree root definitions to merge. Each such tree
417  *	   possibly contains objects, methods and attributes definitions.
418  *
419  * Returns:
420  *	uverbs_root_spec *: The root of the merged parsing tree.
421  *	On error, we return an error code. Error is checked via IS_ERR.
422  *
423  * The following merges could take place:
424  * a. Two trees representing the same method with different handler
425  *	-> We take the handler of the tree that its handler != NULL
426  *	   and its index in the trees array is greater. The incentive for that
427  *	   is that developers are expected to first merge common trees and then
428  *	   merge trees that gives specialized the behaviour.
429  * b. Two trees representing the same object with different
430  *    type_attrs (struct uverbs_obj_type):
431  *	-> We take the type_attrs of the tree that its type_attr != NULL
432  *	   and its index in the trees array is greater. This could be used
433  *	   in order to override the free function, allocation size, etc.
434  * c. Two trees representing the same method attribute (same id but possibly
435  *    different attributes):
436  *	-> ERROR (-ENOENT), we believe that's not the programmer's intent.
437  *
438  * An object without any methods is considered invalid and will abort the
439  * function with -ENOENT error.
440  */
441 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
442 struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
443 						const struct uverbs_object_tree_def **trees);
444 void uverbs_free_spec_tree(struct uverbs_root_spec *root);
445 #else
446 static inline struct uverbs_root_spec *uverbs_alloc_spec_tree(unsigned int num_trees,
447 							      const struct uverbs_object_tree_def **trees)
448 {
449 	return NULL;
450 }
451 
452 static inline void uverbs_free_spec_tree(struct uverbs_root_spec *root)
453 {
454 }
455 #endif
456 
457 #endif
458