net/atm/resources.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* net/atm/resources.c - Statically allocated resources */
   3
   4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   5
   6 /* Fixes
   7  * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   8  * 2002/01 - don't free the whole struct sock on sk->destruct time,
   9  *           use the default destruct function initialized by sock_init_data */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  12
  13 #include <linux/ctype.h>
  14 #include <linux/string.h>
  15 #include <linux/atmdev.h>
  16 #include <linux/sonet.h>
  17 #include <linux/kernel.h> /* for barrier */
  18 #include <linux/module.h>
  19 #include <linux/bitops.h>
  20 #include <linux/capability.h>
  21 #include <linux/delay.h>
  22 #include <linux/mutex.h>
  23 #include <linux/slab.h>
  24
  25 #include <net/sock.h>    /* for struct sock */
  26
  27 #include "common.h"
  28 #include "resources.h"
  29 #include "addr.h"
  30
  31
  32 LIST_HEAD(atm_devs);
  33 DEFINE_MUTEX(atm_dev_mutex);
  34
  35 static struct atm_dev *__alloc_atm_dev(const char *type)
  36 {
  37         struct atm_dev *dev;
  38
  39         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  40         if (!dev)
  41                 return NULL;
  42         dev->type = type;
  43         dev->signal = ATM_PHY_SIG_UNKNOWN;
  44         dev->link_rate = ATM_OC3_PCR;
  45         spin_lock_init(&dev->lock);
  46         INIT_LIST_HEAD(&dev->local);
  47         INIT_LIST_HEAD(&dev->lecs);
  48
  49         return dev;
  50 }
  51
  52 static struct atm_dev *__atm_dev_lookup(int number)
  53 {
  54         struct atm_dev *dev;
  55
  56         list_for_each_entry(dev, &atm_devs, dev_list) {
  57                 if (dev->number == number) {
  58                         atm_dev_hold(dev);
  59                         return dev;
  60                 }
  61         }
  62         return NULL;
  63 }
  64
  65 struct atm_dev *atm_dev_lookup(int number)
  66 {
  67         struct atm_dev *dev;
  68
  69         mutex_lock(&atm_dev_mutex);
  70         dev = __atm_dev_lookup(number);
  71         mutex_unlock(&atm_dev_mutex);
  72         return dev;
  73 }
  74 EXPORT_SYMBOL(atm_dev_lookup);
  75
  76 struct atm_dev *atm_dev_register(const char *type, struct device *parent,
  77                                  const struct atmdev_ops *ops, int number,
  78                                  unsigned long *flags)
  79 {
  80         struct atm_dev *dev, *inuse;
  81
  82         dev = __alloc_atm_dev(type);
  83         if (!dev) {
  84                 pr_err("no space for dev %s\n", type);
  85                 return NULL;
  86         }
  87         mutex_lock(&atm_dev_mutex);
  88         if (number != -1) {
  89                 inuse = __atm_dev_lookup(number);
  90                 if (inuse) {
  91                         atm_dev_put(inuse);
  92                         mutex_unlock(&atm_dev_mutex);
  93                         kfree(dev);
  94                         return NULL;
  95                 }
  96                 dev->number = number;
  97         } else {
  98                 dev->number = 0;
  99                 while ((inuse = __atm_dev_lookup(dev->number))) {
 100                         atm_dev_put(inuse);
 101                         dev->number++;
 102                 }
 103         }
 104
 105         dev->ops = ops;
 106         if (flags)
 107                 dev->flags = *flags;
 108         else
 109                 memset(&dev->flags, 0, sizeof(dev->flags));
 110         memset(&dev->stats, 0, sizeof(dev->stats));
 111         refcount_set(&dev->refcnt, 1);
 112
 113         if (atm_proc_dev_register(dev) < 0) {
 114                 pr_err("atm_proc_dev_register failed for dev %s\n", type);
 115                 goto out_fail;
 116         }
 117
 118         if (atm_register_sysfs(dev, parent) < 0) {
 119                 pr_err("atm_register_sysfs failed for dev %s\n", type);
 120                 atm_proc_dev_deregister(dev);
 121                 goto out_fail;
 122         }
 123
 124         list_add_tail(&dev->dev_list, &atm_devs);
 125
 126 out:
 127         mutex_unlock(&atm_dev_mutex);
 128         return dev;
 129
 130 out_fail:
 131         kfree(dev);
 132         dev = NULL;
 133         goto out;
 134 }
 135 EXPORT_SYMBOL(atm_dev_register);
 136
 137 void atm_dev_deregister(struct atm_dev *dev)
 138 {
 139         BUG_ON(test_bit(ATM_DF_REMOVED, &dev->flags));
 140         set_bit(ATM_DF_REMOVED, &dev->flags);
 141
 142         /*
 143          * if we remove current device from atm_devs list, new device
 144          * with same number can appear, such we need deregister proc,
 145          * release async all vccs and remove them from vccs list too
 146          */
 147         mutex_lock(&atm_dev_mutex);
 148         list_del(&dev->dev_list);
 149         mutex_unlock(&atm_dev_mutex);
 150
 151         atm_dev_release_vccs(dev);
 152         atm_unregister_sysfs(dev);
 153         atm_proc_dev_deregister(dev);
 154
 155         atm_dev_put(dev);
 156 }
 157 EXPORT_SYMBOL(atm_dev_deregister);
 158
 159 static void copy_aal_stats(struct k_atm_aal_stats *from,
 160     struct atm_aal_stats *to)
 161 {
 162 #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
 163         __AAL_STAT_ITEMS
 164 #undef __HANDLE_ITEM
 165 }
 166
 167 static void subtract_aal_stats(struct k_atm_aal_stats *from,
 168     struct atm_aal_stats *to)
 169 {
 170 #define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
 171         __AAL_STAT_ITEMS
 172 #undef __HANDLE_ITEM
 173 }
 174
 175 static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg,
 176                        int zero)
 177 {
 178         struct atm_dev_stats tmp;
 179         int error = 0;
 180
 181         copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
 182         copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
 183         copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
 184         if (arg)
 185                 error = copy_to_user(arg, &tmp, sizeof(tmp));
 186         if (zero && !error) {
 187                 subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
 188                 subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
 189                 subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
 190         }
 191         return error ? -EFAULT : 0;
 192 }
 193
 194 int atm_getnames(void __user *buf, int __user *iobuf_len)
 195 {
 196         int error, len, size = 0;
 197         struct atm_dev *dev;
 198         struct list_head *p;
 199         int *tmp_buf, *tmp_p;
 200
 201         if (get_user(len, iobuf_len))
 202                 return -EFAULT;
 203         mutex_lock(&atm_dev_mutex);
 204         list_for_each(p, &atm_devs)
 205                 size += sizeof(int);
 206         if (size > len) {
 207                 mutex_unlock(&atm_dev_mutex);
 208                 return -E2BIG;
 209         }
 210         tmp_buf = kmalloc(size, GFP_ATOMIC);
 211         if (!tmp_buf) {
 212                 mutex_unlock(&atm_dev_mutex);
 213                 return -ENOMEM;
 214         }
 215         tmp_p = tmp_buf;
 216         list_for_each_entry(dev, &atm_devs, dev_list) {
 217                 *tmp_p++ = dev->number;
 218         }
 219         mutex_unlock(&atm_dev_mutex);
 220         error = ((copy_to_user(buf, tmp_buf, size)) ||
 221                  put_user(size, iobuf_len))
 222                 ? -EFAULT : 0;
 223         kfree(tmp_buf);
 224         return error;
 225 }
 226
 227 int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
 228                   int number, int compat)
 229 {
 230         int error, len, size = 0;
 231         struct atm_dev *dev;
 232
 233         if (get_user(len, sioc_len))
 234                 return -EFAULT;
 235
 236         dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
 237                                       number);
 238         if (!dev)
 239                 return -ENODEV;
 240
 241         switch (cmd) {
 242         case ATM_GETTYPE:
 243                 size = strlen(dev->type) + 1;
 244                 if (copy_to_user(buf, dev->type, size)) {
 245                         error = -EFAULT;
 246                         goto done;
 247                 }
 248                 break;
 249         case ATM_GETESI:
 250                 size = ESI_LEN;
 251                 if (copy_to_user(buf, dev->esi, size)) {
 252                         error = -EFAULT;
 253                         goto done;
 254                 }
 255                 break;
 256         case ATM_SETESI:
 257         {
 258                 int i;
 259
 260                 for (i = 0; i < ESI_LEN; i++)
 261                         if (dev->esi[i]) {
 262                                 error = -EEXIST;
 263                                 goto done;
 264                         }
 265         }
 266                 fallthrough;
 267         case ATM_SETESIF:
 268         {
 269                 unsigned char esi[ESI_LEN];
 270
 271                 if (!capable(CAP_NET_ADMIN)) {
 272                         error = -EPERM;
 273                         goto done;
 274                 }
 275                 if (copy_from_user(esi, buf, ESI_LEN)) {
 276                         error = -EFAULT;
 277                         goto done;
 278                 }
 279                 memcpy(dev->esi, esi, ESI_LEN);
 280                 error =  ESI_LEN;
 281                 goto done;
 282         }
 283         case ATM_GETSTATZ:
 284                 if (!capable(CAP_NET_ADMIN)) {
 285                         error = -EPERM;
 286                         goto done;
 287                 }
 288                 fallthrough;
 289         case ATM_GETSTAT:
 290                 size = sizeof(struct atm_dev_stats);
 291                 error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
 292                 if (error)
 293                         goto done;
 294                 break;
 295         case ATM_GETCIRANGE:
 296                 size = sizeof(struct atm_cirange);
 297                 if (copy_to_user(buf, &dev->ci_range, size)) {
 298                         error = -EFAULT;
 299                         goto done;
 300                 }
 301                 break;
 302         case ATM_GETLINKRATE:
 303                 size = sizeof(int);
 304                 if (copy_to_user(buf, &dev->link_rate, size)) {
 305                         error = -EFAULT;
 306                         goto done;
 307                 }
 308                 break;
 309         case ATM_RSTADDR:
 310                 if (!capable(CAP_NET_ADMIN)) {
 311                         error = -EPERM;
 312                         goto done;
 313                 }
 314                 atm_reset_addr(dev, ATM_ADDR_LOCAL);
 315                 break;
 316         case ATM_ADDADDR:
 317         case ATM_DELADDR:
 318         case ATM_ADDLECSADDR:
 319         case ATM_DELLECSADDR:
 320         {
 321                 struct sockaddr_atmsvc addr;
 322
 323                 if (!capable(CAP_NET_ADMIN)) {
 324                         error = -EPERM;
 325                         goto done;
 326                 }
 327
 328                 if (copy_from_user(&addr, buf, sizeof(addr))) {
 329                         error = -EFAULT;
 330                         goto done;
 331                 }
 332                 if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
 333                         error = atm_add_addr(dev, &addr,
 334                                              (cmd == ATM_ADDADDR ?
 335                                               ATM_ADDR_LOCAL : ATM_ADDR_LECS));
 336                 else
 337                         error = atm_del_addr(dev, &addr,
 338                                              (cmd == ATM_DELADDR ?
 339                                               ATM_ADDR_LOCAL : ATM_ADDR_LECS));
 340                 goto done;
 341         }
 342         case ATM_GETADDR:
 343         case ATM_GETLECSADDR:
 344                 error = atm_get_addr(dev, buf, len,
 345                                      (cmd == ATM_GETADDR ?
 346                                       ATM_ADDR_LOCAL : ATM_ADDR_LECS));
 347                 if (error < 0)
 348                         goto done;
 349                 size = error;
 350                 /* may return 0, but later on size == 0 means "don't
 351                    write the length" */
 352                 error = put_user(size, sioc_len) ? -EFAULT : 0;
 353                 goto done;
 354         case ATM_SETLOOP:
 355                 if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
 356                     __ATM_LM_XTLOC((int) (unsigned long) buf) >
 357                     __ATM_LM_XTRMT((int) (unsigned long) buf)) {
 358                         error = -EINVAL;
 359                         goto done;
 360                 }
 361                 fallthrough;
 362         case ATM_SETCIRANGE:
 363         case SONET_GETSTATZ:
 364         case SONET_SETDIAG:
 365         case SONET_CLRDIAG:
 366         case SONET_SETFRAMING:
 367                 if (!capable(CAP_NET_ADMIN)) {
 368                         error = -EPERM;
 369                         goto done;
 370                 }
 371                 fallthrough;
 372         default:
 373                 if (IS_ENABLED(CONFIG_COMPAT) && compat) {
 374 #ifdef CONFIG_COMPAT
 375                         if (!dev->ops->compat_ioctl) {
 376                                 error = -EINVAL;
 377                                 goto done;
 378                         }
 379                         size = dev->ops->compat_ioctl(dev, cmd, buf);
 380 #endif
 381                 } else {
 382                         if (!dev->ops->ioctl) {
 383                                 error = -EINVAL;
 384                                 goto done;
 385                         }
 386                         size = dev->ops->ioctl(dev, cmd, buf);
 387                 }
 388                 if (size < 0) {
 389                         error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
 390                         goto done;
 391                 }
 392         }
 393
 394         if (size)
 395                 error = put_user(size, sioc_len) ? -EFAULT : 0;
 396         else
 397                 error = 0;
 398 done:
 399         atm_dev_put(dev);
 400         return error;
 401 }
 402
 403 void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
 404 {
 405         mutex_lock(&atm_dev_mutex);
 406         return seq_list_start_head(&atm_devs, *pos);
 407 }
 408
 409 void atm_dev_seq_stop(struct seq_file *seq, void *v)
 410 {
 411         mutex_unlock(&atm_dev_mutex);
 412 }
 413
 414 void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 415 {
 416         return seq_list_next(v, &atm_devs, pos);
 417 }