drivers/infiniband/core/uverbs_ioctl.c

   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 #include <rdma/rdma_user_ioctl.h>
  34 #include <rdma/uverbs_ioctl.h>
  35 #include "rdma_core.h"
  36 #include "uverbs.h"
  37
  38 static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
  39                                    u16 len)
  40 {
  41         if (uattr->len > sizeof(((struct ib_uverbs_attr *)0)->data))
  42                 return ib_is_buffer_cleared(u64_to_user_ptr(uattr->data) + len,
  43                                             uattr->len - len);
  44
  45         return !memchr_inv((const void *)&uattr->data + len,
  46                            0, uattr->len - len);
  47 }
  48
  49 static int uverbs_process_attr(struct ib_device *ibdev,
  50                                struct ib_ucontext *ucontext,
  51                                const struct ib_uverbs_attr *uattr,
  52                                u16 attr_id,
  53                                const struct uverbs_attr_spec_hash *attr_spec_bucket,
  54                                struct uverbs_attr_bundle_hash *attr_bundle_h,
  55                                struct ib_uverbs_attr __user *uattr_ptr)
  56 {
  57         const struct uverbs_attr_spec *spec;
  58         const struct uverbs_attr_spec *val_spec;
  59         struct uverbs_attr *e;
  60         const struct uverbs_object_spec *object;
  61         struct uverbs_obj_attr *o_attr;
  62         struct uverbs_attr *elements = attr_bundle_h->attrs;
  63
  64         if (attr_id >= attr_spec_bucket->num_attrs) {
  65                 if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
  66                         return -EINVAL;
  67                 else
  68                         return 0;
  69         }
  70
  71         if (test_bit(attr_id, attr_bundle_h->valid_bitmap))
  72                 return -EINVAL;
  73
  74         spec = &attr_spec_bucket->attrs[attr_id];
  75         val_spec = spec;
  76         e = &elements[attr_id];
  77         e->uattr = uattr_ptr;
  78
  79         switch (spec->type) {
  80         case UVERBS_ATTR_TYPE_ENUM_IN:
  81                 if (uattr->attr_data.enum_data.elem_id >= spec->enum_def.num_elems)
  82                         return -EOPNOTSUPP;
  83
  84                 if (uattr->attr_data.enum_data.reserved)
  85                         return -EINVAL;
  86
  87                 val_spec = &spec->enum_def.ids[uattr->attr_data.enum_data.elem_id];
  88
  89                 /* Currently we only support PTR_IN based enums */
  90                 if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
  91                         return -EOPNOTSUPP;
  92
  93                 e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
  94         /* fall through */
  95         case UVERBS_ATTR_TYPE_PTR_IN:
  96                 /* Ensure that any data provided by userspace beyond the known
  97                  * struct is zero. Userspace that knows how to use some future
  98                  * longer struct will fail here if used with an old kernel and
  99                  * non-zero content, making ABI compat/discovery simpler.
 100                  */
 101                 if (uattr->len > val_spec->ptr.len &&
 102                     val_spec->flags & UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO &&
 103                     !uverbs_is_attr_cleared(uattr, val_spec->ptr.len))
 104                         return -EOPNOTSUPP;
 105
 106         /* fall through */
 107         case UVERBS_ATTR_TYPE_PTR_OUT:
 108                 if (uattr->len < val_spec->ptr.min_len ||
 109                     (!(val_spec->flags & UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO) &&
 110                      uattr->len > val_spec->ptr.len))
 111                         return -EINVAL;
 112
 113                 if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
 114                     uattr->attr_data.reserved)
 115                         return -EINVAL;
 116
 117                 e->ptr_attr.data = uattr->data;
 118                 e->ptr_attr.len = uattr->len;
 119                 e->ptr_attr.flags = uattr->flags;
 120                 break;
 121
 122         case UVERBS_ATTR_TYPE_IDR:
 123                 if (uattr->data >> 32)
 124                         return -EINVAL;
 125         /* fall through */
 126         case UVERBS_ATTR_TYPE_FD:
 127                 if (uattr->attr_data.reserved)
 128                         return -EINVAL;
 129
 130                 if (uattr->len != 0 || !ucontext || uattr->data > INT_MAX)
 131                         return -EINVAL;
 132
 133                 o_attr = &e->obj_attr;
 134                 object = uverbs_get_object(ibdev, spec->obj.obj_type);
 135                 if (!object)
 136                         return -EINVAL;
 137                 o_attr->type = object->type_attrs;
 138
 139                 o_attr->id = (int)uattr->data;
 140                 o_attr->uobject = uverbs_get_uobject_from_context(
 141                                         o_attr->type,
 142                                         ucontext,
 143                                         spec->obj.access,
 144                                         o_attr->id);
 145
 146                 if (IS_ERR(o_attr->uobject))
 147                         return PTR_ERR(o_attr->uobject);
 148
 149                 if (spec->obj.access == UVERBS_ACCESS_NEW) {
 150                         u64 id = o_attr->uobject->id;
 151
 152                         /* Copy the allocated id to the user-space */
 153                         if (put_user(id, &e->uattr->data)) {
 154                                 uverbs_finalize_object(o_attr->uobject,
 155                                                        UVERBS_ACCESS_NEW,
 156                                                        false);
 157                                 return -EFAULT;
 158                         }
 159                 }
 160
 161                 break;
 162         default:
 163                 return -EOPNOTSUPP;
 164         }
 165
 166         set_bit(attr_id, attr_bundle_h->valid_bitmap);
 167         return 0;
 168 }
 169
 170 static int uverbs_uattrs_process(struct ib_device *ibdev,
 171                                  struct ib_ucontext *ucontext,
 172                                  const struct ib_uverbs_attr *uattrs,
 173                                  size_t num_uattrs,
 174                                  const struct uverbs_method_spec *method,
 175                                  struct uverbs_attr_bundle *attr_bundle,
 176                                  struct ib_uverbs_attr __user *uattr_ptr)
 177 {
 178         size_t i;
 179         int ret = 0;
 180         int num_given_buckets = 0;
 181
 182         for (i = 0; i < num_uattrs; i++) {
 183                 const struct ib_uverbs_attr *uattr = &uattrs[i];
 184                 u16 attr_id = uattr->attr_id;
 185                 struct uverbs_attr_spec_hash *attr_spec_bucket;
 186
 187                 ret = uverbs_ns_idx(&attr_id, method->num_buckets);
 188                 if (ret < 0) {
 189                         if (uattr->flags & UVERBS_ATTR_F_MANDATORY) {
 190                                 uverbs_finalize_objects(attr_bundle,
 191                                                         method->attr_buckets,
 192                                                         num_given_buckets,
 193                                                         false);
 194                                 return ret;
 195                         }
 196                         continue;
 197                 }
 198
 199                 /*
 200                  * ret is the found ns, so increase num_given_buckets if
 201                  * necessary.
 202                  */
 203                 if (ret >= num_given_buckets)
 204                         num_given_buckets = ret + 1;
 205
 206                 attr_spec_bucket = method->attr_buckets[ret];
 207                 ret = uverbs_process_attr(ibdev, ucontext, uattr, attr_id,
 208                                           attr_spec_bucket, &attr_bundle->hash[ret],
 209                                           uattr_ptr++);
 210                 if (ret) {
 211                         uverbs_finalize_objects(attr_bundle,
 212                                                 method->attr_buckets,
 213                                                 num_given_buckets,
 214                                                 false);
 215                         return ret;
 216                 }
 217         }
 218
 219         return num_given_buckets;
 220 }
 221
 222 static int uverbs_validate_kernel_mandatory(const struct uverbs_method_spec *method_spec,
 223                                             struct uverbs_attr_bundle *attr_bundle)
 224 {
 225         unsigned int i;
 226
 227         for (i = 0; i < attr_bundle->num_buckets; i++) {
 228                 struct uverbs_attr_spec_hash *attr_spec_bucket =
 229                         method_spec->attr_buckets[i];
 230
 231                 if (!bitmap_subset(attr_spec_bucket->mandatory_attrs_bitmask,
 232                                    attr_bundle->hash[i].valid_bitmap,
 233                                    attr_spec_bucket->num_attrs))
 234                         return -EINVAL;
 235         }
 236
 237         return 0;
 238 }
 239
 240 static int uverbs_handle_method(struct ib_uverbs_attr __user *uattr_ptr,
 241                                 const struct ib_uverbs_attr *uattrs,
 242                                 size_t num_uattrs,
 243                                 struct ib_device *ibdev,
 244                                 struct ib_uverbs_file *ufile,
 245                                 const struct uverbs_method_spec *method_spec,
 246                                 struct uverbs_attr_bundle *attr_bundle)
 247 {
 248         int ret;
 249         int finalize_ret;
 250         int num_given_buckets;
 251
 252         num_given_buckets = uverbs_uattrs_process(ibdev, ufile->ucontext, uattrs,
 253                                                   num_uattrs, method_spec,
 254                                                   attr_bundle, uattr_ptr);
 255         if (num_given_buckets <= 0)
 256                 return -EINVAL;
 257
 258         attr_bundle->num_buckets = num_given_buckets;
 259         ret = uverbs_validate_kernel_mandatory(method_spec, attr_bundle);
 260         if (ret)
 261                 goto cleanup;
 262
 263         ret = method_spec->handler(ibdev, ufile, attr_bundle);
 264 cleanup:
 265         finalize_ret = uverbs_finalize_objects(attr_bundle,
 266                                                method_spec->attr_buckets,
 267                                                attr_bundle->num_buckets,
 268                                                !ret);
 269
 270         return ret ? ret : finalize_ret;
 271 }
 272
 273 #define UVERBS_OPTIMIZE_USING_STACK_SZ  256
 274 static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
 275                                 struct ib_uverbs_file *file,
 276                                 struct ib_uverbs_ioctl_hdr *hdr,
 277                                 void __user *buf)
 278 {
 279         const struct uverbs_object_spec *object_spec;
 280         const struct uverbs_method_spec *method_spec;
 281         long err = 0;
 282         unsigned int i;
 283         struct {
 284                 struct ib_uverbs_attr           *uattrs;
 285                 struct uverbs_attr_bundle       *uverbs_attr_bundle;
 286         } *ctx = NULL;
 287         struct uverbs_attr *curr_attr;
 288         unsigned long *curr_bitmap;
 289         size_t ctx_size;
 290         uintptr_t data[UVERBS_OPTIMIZE_USING_STACK_SZ / sizeof(uintptr_t)];
 291
 292         if (hdr->driver_id != ib_dev->driver_id)
 293                 return -EINVAL;
 294
 295         object_spec = uverbs_get_object(ib_dev, hdr->object_id);
 296         if (!object_spec)
 297                 return -EPROTONOSUPPORT;
 298
 299         method_spec = uverbs_get_method(object_spec, hdr->method_id);
 300         if (!method_spec)
 301                 return -EPROTONOSUPPORT;
 302
 303         if ((method_spec->flags & UVERBS_ACTION_FLAG_CREATE_ROOT) ^ !file->ucontext)
 304                 return -EINVAL;
 305
 306         ctx_size = sizeof(*ctx) +
 307                    sizeof(struct uverbs_attr_bundle) +
 308                    sizeof(struct uverbs_attr_bundle_hash) * method_spec->num_buckets +
 309                    sizeof(*ctx->uattrs) * hdr->num_attrs +
 310                    sizeof(*ctx->uverbs_attr_bundle->hash[0].attrs) *
 311                    method_spec->num_child_attrs +
 312                    sizeof(*ctx->uverbs_attr_bundle->hash[0].valid_bitmap) *
 313                         (method_spec->num_child_attrs / BITS_PER_LONG +
 314                          method_spec->num_buckets);
 315
 316         if (ctx_size <= UVERBS_OPTIMIZE_USING_STACK_SZ)
 317                 ctx = (void *)data;
 318         if (!ctx)
 319                 ctx = kmalloc(ctx_size, GFP_KERNEL);
 320         if (!ctx)
 321                 return -ENOMEM;
 322
 323         ctx->uverbs_attr_bundle = (void *)ctx + sizeof(*ctx);
 324         ctx->uattrs = (void *)(ctx->uverbs_attr_bundle + 1) +
 325                               (sizeof(ctx->uverbs_attr_bundle->hash[0]) *
 326                                method_spec->num_buckets);
 327         curr_attr = (void *)(ctx->uattrs + hdr->num_attrs);
 328         curr_bitmap = (void *)(curr_attr + method_spec->num_child_attrs);
 329
 330         /*
 331          * We just fill the pointers and num_attrs here. The data itself will be
 332          * filled at a later stage (uverbs_process_attr)
 333          */
 334         for (i = 0; i < method_spec->num_buckets; i++) {
 335                 unsigned int curr_num_attrs = method_spec->attr_buckets[i]->num_attrs;
 336
 337                 ctx->uverbs_attr_bundle->hash[i].attrs = curr_attr;
 338                 curr_attr += curr_num_attrs;
 339                 ctx->uverbs_attr_bundle->hash[i].num_attrs = curr_num_attrs;
 340                 ctx->uverbs_attr_bundle->hash[i].valid_bitmap = curr_bitmap;
 341                 bitmap_zero(curr_bitmap, curr_num_attrs);
 342                 curr_bitmap += BITS_TO_LONGS(curr_num_attrs);
 343         }
 344
 345         err = copy_from_user(ctx->uattrs, buf,
 346                              sizeof(*ctx->uattrs) * hdr->num_attrs);
 347         if (err) {
 348                 err = -EFAULT;
 349                 goto out;
 350         }
 351
 352         err = uverbs_handle_method(buf, ctx->uattrs, hdr->num_attrs, ib_dev,
 353                                    file, method_spec, ctx->uverbs_attr_bundle);
 354
 355         /*
 356          * EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
 357          * not invoke the method because the request is not supported.  No
 358          * other cases should return this code.
 359         */
 360         if (unlikely(err == -EPROTONOSUPPORT)) {
 361                 WARN_ON_ONCE(err == -EPROTONOSUPPORT);
 362                 err = -EINVAL;
 363         }
 364 out:
 365         if (ctx != (void *)data)
 366                 kfree(ctx);
 367         return err;
 368 }
 369
 370 #define IB_UVERBS_MAX_CMD_SZ 4096
 371
 372 long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 373 {
 374         struct ib_uverbs_file *file = filp->private_data;
 375         struct ib_uverbs_ioctl_hdr __user *user_hdr =
 376                 (struct ib_uverbs_ioctl_hdr __user *)arg;
 377         struct ib_uverbs_ioctl_hdr hdr;
 378         struct ib_device *ib_dev;
 379         int srcu_key;
 380         long err;
 381
 382         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 383         ib_dev = srcu_dereference(file->device->ib_dev,
 384                                   &file->device->disassociate_srcu);
 385         if (!ib_dev) {
 386                 err = -EIO;
 387                 goto out;
 388         }
 389
 390         if (cmd == RDMA_VERBS_IOCTL) {
 391                 err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
 392
 393                 if (err || hdr.length > IB_UVERBS_MAX_CMD_SZ ||
 394                     hdr.length != sizeof(hdr) + hdr.num_attrs * sizeof(struct ib_uverbs_attr)) {
 395                         err = -EINVAL;
 396                         goto out;
 397                 }
 398
 399                 if (hdr.reserved1 || hdr.reserved2) {
 400                         err = -EPROTONOSUPPORT;
 401                         goto out;
 402                 }
 403
 404                 err = ib_uverbs_cmd_verbs(ib_dev, file, &hdr,
 405                                           (__user void *)arg + sizeof(hdr));
 406         } else {
 407                 err = -ENOIOCTLCMD;
 408         }
 409 out:
 410         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 411
 412         return err;
 413 }