drivers/staging/pohmelfs/config.c

   1 /*
   2  * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
   3  * All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/connector.h>
  18 #include <linux/crypto.h>
  19 #include <linux/list.h>
  20 #include <linux/mutex.h>
  21 #include <linux/string.h>
  22 #include <linux/in.h>
  23 #include <linux/slab.h>
  24
  25 #include "netfs.h"
  26
  27 /*
  28  * Global configuration list.
  29  * Each client can be asked to get one of them.
  30  *
  31  * Allows to provide remote server address (ipv4/v6/whatever), port
  32  * and so on via kernel connector.
  33  */
  34
  35 static struct cb_id pohmelfs_cn_id = {.idx = POHMELFS_CN_IDX, .val = POHMELFS_CN_VAL};
  36 static LIST_HEAD(pohmelfs_config_list);
  37 static DEFINE_MUTEX(pohmelfs_config_lock);
  38
  39 static inline int pohmelfs_config_eql(struct pohmelfs_ctl *sc, struct pohmelfs_ctl *ctl)
  40 {
  41         if (sc->idx == ctl->idx && sc->type == ctl->type &&
  42                         sc->proto == ctl->proto &&
  43                         sc->addrlen == ctl->addrlen &&
  44                         !memcmp(&sc->addr, &ctl->addr, ctl->addrlen))
  45                 return 1;
  46
  47         return 0;
  48 }
  49
  50 static struct pohmelfs_config_group *pohmelfs_find_config_group(unsigned int idx)
  51 {
  52         struct pohmelfs_config_group *g, *group = NULL;
  53
  54         list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
  55                 if (g->idx == idx) {
  56                         group = g;
  57                         break;
  58                 }
  59         }
  60
  61         return group;
  62 }
  63
  64 static struct pohmelfs_config_group *pohmelfs_find_create_config_group(unsigned int idx)
  65 {
  66         struct pohmelfs_config_group *g;
  67
  68         g = pohmelfs_find_config_group(idx);
  69         if (g)
  70                 return g;
  71
  72         g = kzalloc(sizeof(struct pohmelfs_config_group), GFP_KERNEL);
  73         if (!g)
  74                 return NULL;
  75
  76         INIT_LIST_HEAD(&g->config_list);
  77         g->idx = idx;
  78         g->num_entry = 0;
  79
  80         list_add_tail(&g->group_entry, &pohmelfs_config_list);
  81
  82         return g;
  83 }
  84
  85 static inline void pohmelfs_insert_config_entry(struct pohmelfs_sb *psb, struct pohmelfs_config *dst)
  86 {
  87         struct pohmelfs_config *tmp;
  88
  89         INIT_LIST_HEAD(&dst->config_entry);
  90
  91         list_for_each_entry(tmp, &psb->state_list, config_entry) {
  92                 if (dst->state.ctl.prio > tmp->state.ctl.prio)
  93                         list_add_tail(&dst->config_entry, &tmp->config_entry);
  94         }
  95         if (list_empty(&dst->config_entry))
  96                 list_add_tail(&dst->config_entry, &psb->state_list);
  97 }
  98
  99 static int pohmelfs_move_config_entry(struct pohmelfs_sb *psb,
 100                 struct pohmelfs_config *dst, struct pohmelfs_config *new)
 101 {
 102         if ((dst->state.ctl.prio == new->state.ctl.prio) &&
 103                 (dst->state.ctl.perm == new->state.ctl.perm))
 104                 return 0;
 105
 106         dprintk("%s: dst: prio: %d, perm: %x, new: prio: %d, perm: %d.\n",
 107                         __func__, dst->state.ctl.prio, dst->state.ctl.perm,
 108                         new->state.ctl.prio, new->state.ctl.perm);
 109         dst->state.ctl.prio = new->state.ctl.prio;
 110         dst->state.ctl.perm = new->state.ctl.perm;
 111
 112         list_del_init(&dst->config_entry);
 113         pohmelfs_insert_config_entry(psb, dst);
 114         return 0;
 115 }
 116
 117 /*
 118  * pohmelfs_copy_config() is used to copy new state configs from the
 119  * config group (controlled by the netlink messages) into the superblock.
 120  * This happens either at startup time where no transactions can access
 121  * the list of the configs (and thus list of the network states), or at
 122  * run-time, where it is protected by the psb->state_lock.
 123  */
 124 int pohmelfs_copy_config(struct pohmelfs_sb *psb)
 125 {
 126         struct pohmelfs_config_group *g;
 127         struct pohmelfs_config *c, *dst;
 128         int err = -ENODEV;
 129
 130         mutex_lock(&pohmelfs_config_lock);
 131
 132         g = pohmelfs_find_config_group(psb->idx);
 133         if (!g)
 134                 goto out_unlock;
 135
 136         /*
 137          * Run over all entries in given config group and try to create and
 138          * initialize those, which do not exist in superblock list.
 139          * Skip all existing entries.
 140          */
 141
 142         list_for_each_entry(c, &g->config_list, config_entry) {
 143                 err = 0;
 144                 list_for_each_entry(dst, &psb->state_list, config_entry) {
 145                         if (pohmelfs_config_eql(&dst->state.ctl, &c->state.ctl)) {
 146                                 err = pohmelfs_move_config_entry(psb, dst, c);
 147                                 if (!err)
 148                                         err = -EEXIST;
 149                                 break;
 150                         }
 151                 }
 152
 153                 if (err)
 154                         continue;
 155
 156                 dst = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
 157                 if (!dst) {
 158                         err = -ENOMEM;
 159                         break;
 160                 }
 161
 162                 memcpy(&dst->state.ctl, &c->state.ctl, sizeof(struct pohmelfs_ctl));
 163
 164                 pohmelfs_insert_config_entry(psb, dst);
 165
 166                 err = pohmelfs_state_init_one(psb, dst);
 167                 if (err) {
 168                         list_del(&dst->config_entry);
 169                         kfree(dst);
 170                 }
 171
 172                 err = 0;
 173         }
 174
 175 out_unlock:
 176         mutex_unlock(&pohmelfs_config_lock);
 177
 178         return err;
 179 }
 180
 181 int pohmelfs_copy_crypto(struct pohmelfs_sb *psb)
 182 {
 183         struct pohmelfs_config_group *g;
 184         int err = -ENOENT;
 185
 186         mutex_lock(&pohmelfs_config_lock);
 187         g = pohmelfs_find_config_group(psb->idx);
 188         if (!g)
 189                 goto err_out_exit;
 190
 191         if (g->hash_string) {
 192                 err = -ENOMEM;
 193                 psb->hash_string = kstrdup(g->hash_string, GFP_KERNEL);
 194                 if (!psb->hash_string)
 195                         goto err_out_exit;
 196                 psb->hash_strlen = g->hash_strlen;
 197         }
 198
 199         if (g->cipher_string) {
 200                 psb->cipher_string = kstrdup(g->cipher_string, GFP_KERNEL);
 201                 if (!psb->cipher_string)
 202                         goto err_out_free_hash_string;
 203                 psb->cipher_strlen = g->cipher_strlen;
 204         }
 205
 206         if (g->hash_keysize) {
 207                 psb->hash_key = kmemdup(g->hash_key, g->hash_keysize,
 208                                         GFP_KERNEL);
 209                 if (!psb->hash_key)
 210                         goto err_out_free_cipher_string;
 211                 psb->hash_keysize = g->hash_keysize;
 212         }
 213
 214         if (g->cipher_keysize) {
 215                 psb->cipher_key = kmemdup(g->cipher_key, g->cipher_keysize,
 216                                           GFP_KERNEL);
 217                 if (!psb->cipher_key)
 218                         goto err_out_free_hash;
 219                 psb->cipher_keysize = g->cipher_keysize;
 220         }
 221
 222         mutex_unlock(&pohmelfs_config_lock);
 223
 224         return 0;
 225
 226 err_out_free_hash:
 227         kfree(psb->hash_key);
 228 err_out_free_cipher_string:
 229         kfree(psb->cipher_string);
 230 err_out_free_hash_string:
 231         kfree(psb->hash_string);
 232 err_out_exit:
 233         mutex_unlock(&pohmelfs_config_lock);
 234         return err;
 235 }
 236
 237 static int pohmelfs_send_reply(int err, int msg_num, int action, struct cn_msg *msg, struct pohmelfs_ctl *ctl)
 238 {
 239         struct pohmelfs_cn_ack *ack;
 240
 241         ack = kzalloc(sizeof(struct pohmelfs_cn_ack), GFP_KERNEL);
 242         if (!ack)
 243                 return -ENOMEM;
 244
 245         memcpy(&ack->msg, msg, sizeof(struct cn_msg));
 246
 247         if (action == POHMELFS_CTLINFO_ACK)
 248                 memcpy(&ack->ctl, ctl, sizeof(struct pohmelfs_ctl));
 249
 250         ack->msg.len = sizeof(struct pohmelfs_cn_ack) - sizeof(struct cn_msg);
 251         ack->msg.ack = msg->ack + 1;
 252         ack->error = err;
 253         ack->msg_num = msg_num;
 254
 255         cn_netlink_send(&ack->msg, 0, GFP_KERNEL);
 256         kfree(ack);
 257         return 0;
 258 }
 259
 260 static int pohmelfs_cn_disp(struct cn_msg *msg)
 261 {
 262         struct pohmelfs_config_group *g;
 263         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 264         struct pohmelfs_config *c, *tmp;
 265         int err = 0, i = 1;
 266
 267         if (msg->len != sizeof(struct pohmelfs_ctl))
 268                 return -EBADMSG;
 269
 270         mutex_lock(&pohmelfs_config_lock);
 271
 272         g = pohmelfs_find_config_group(ctl->idx);
 273         if (!g) {
 274                 pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL);
 275                 goto out_unlock;
 276         }
 277
 278         list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 279                 struct pohmelfs_ctl *sc = &c->state.ctl;
 280                 if (pohmelfs_send_reply(err, g->num_entry - i, POHMELFS_CTLINFO_ACK, msg, sc)) {
 281                         err = -ENOMEM;
 282                         goto out_unlock;
 283                 }
 284                 i += 1;
 285         }
 286
 287  out_unlock:
 288         mutex_unlock(&pohmelfs_config_lock);
 289         return err;
 290 }
 291
 292 static int pohmelfs_cn_dump(struct cn_msg *msg)
 293 {
 294         struct pohmelfs_config_group *g;
 295         struct pohmelfs_config *c, *tmp;
 296         int err = 0, i = 1;
 297         int total_msg = 0;
 298
 299         if (msg->len != sizeof(struct pohmelfs_ctl))
 300                 return -EBADMSG;
 301
 302         mutex_lock(&pohmelfs_config_lock);
 303
 304         list_for_each_entry(g, &pohmelfs_config_list, group_entry)
 305                 total_msg += g->num_entry;
 306         if (total_msg == 0) {
 307                 if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 308                         err = -ENOMEM;
 309                 goto out_unlock;
 310         }
 311
 312         list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
 313                 list_for_each_entry_safe(c, tmp, &g->config_list,
 314                                          config_entry) {
 315                         struct pohmelfs_ctl *sc = &c->state.ctl;
 316                         if (pohmelfs_send_reply(err, total_msg - i,
 317                                                 POHMELFS_CTLINFO_ACK, msg,
 318                                                 sc)) {
 319                                 err = -ENOMEM;
 320                                 goto out_unlock;
 321                         }
 322                         i += 1;
 323                 }
 324         }
 325
 326 out_unlock:
 327         mutex_unlock(&pohmelfs_config_lock);
 328         return err;
 329 }
 330
 331 static int pohmelfs_cn_flush(struct cn_msg *msg)
 332 {
 333         struct pohmelfs_config_group *g;
 334         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 335         struct pohmelfs_config *c, *tmp;
 336         int err = 0;
 337
 338         if (msg->len != sizeof(struct pohmelfs_ctl))
 339                 return -EBADMSG;
 340
 341         mutex_lock(&pohmelfs_config_lock);
 342
 343         if (ctl->idx != POHMELFS_NULL_IDX) {
 344                 g = pohmelfs_find_config_group(ctl->idx);
 345
 346                 if (!g)
 347                         goto out_unlock;
 348
 349                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 350                         list_del(&c->config_entry);
 351                         g->num_entry--;
 352                         kfree(c);
 353                 }
 354         } else {
 355                 list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
 356                         list_for_each_entry_safe(c, tmp, &g->config_list,
 357                                                  config_entry) {
 358                                 list_del(&c->config_entry);
 359                                 g->num_entry--;
 360                                 kfree(c);
 361                         }
 362                 }
 363         }
 364
 365 out_unlock:
 366         mutex_unlock(&pohmelfs_config_lock);
 367         pohmelfs_cn_dump(msg);
 368
 369         return err;
 370 }
 371
 372 static int pohmelfs_modify_config(struct pohmelfs_ctl *old, struct pohmelfs_ctl *new)
 373 {
 374         old->perm = new->perm;
 375         old->prio = new->prio;
 376         return 0;
 377 }
 378
 379 static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 380 {
 381         struct pohmelfs_config_group *g;
 382         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 383         struct pohmelfs_config *c, *tmp;
 384         int err = 0;
 385
 386         if (msg->len != sizeof(struct pohmelfs_ctl))
 387                 return -EBADMSG;
 388
 389         mutex_lock(&pohmelfs_config_lock);
 390
 391         g = pohmelfs_find_create_config_group(ctl->idx);
 392         if (!g) {
 393                 err = -ENOMEM;
 394                 goto out_unlock;
 395         }
 396
 397         list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 398                 struct pohmelfs_ctl *sc = &c->state.ctl;
 399
 400                 if (pohmelfs_config_eql(sc, ctl)) {
 401                         if (action == POHMELFS_FLAGS_ADD) {
 402                                 err = -EEXIST;
 403                                 goto out_unlock;
 404                         } else if (action == POHMELFS_FLAGS_DEL) {
 405                                 list_del(&c->config_entry);
 406                                 g->num_entry--;
 407                                 kfree(c);
 408                                 goto out_unlock;
 409                         } else if (action == POHMELFS_FLAGS_MODIFY) {
 410                                 err = pohmelfs_modify_config(sc, ctl);
 411                                 goto out_unlock;
 412                         } else {
 413                                 err = -EEXIST;
 414                                 goto out_unlock;
 415                         }
 416                 }
 417         }
 418         if (action == POHMELFS_FLAGS_DEL) {
 419                 err = -EBADMSG;
 420                 goto out_unlock;
 421         }
 422
 423         c = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
 424         if (!c) {
 425                 err = -ENOMEM;
 426                 goto out_unlock;
 427         }
 428         memcpy(&c->state.ctl, ctl, sizeof(struct pohmelfs_ctl));
 429         g->num_entry++;
 430
 431         list_add_tail(&c->config_entry, &g->config_list);
 432
 433  out_unlock:
 434         mutex_unlock(&pohmelfs_config_lock);
 435         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 436                 err = -ENOMEM;
 437
 438         return err;
 439 }
 440
 441 static int pohmelfs_crypto_hash_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 442 {
 443         char *algo = (char *)c->data;
 444         u8 *key = (u8 *)(algo + c->strlen);
 445
 446         if (g->hash_string)
 447                 return -EEXIST;
 448
 449         g->hash_string = kstrdup(algo, GFP_KERNEL);
 450         if (!g->hash_string)
 451                 return -ENOMEM;
 452         g->hash_strlen = c->strlen;
 453         g->hash_keysize = c->keysize;
 454
 455         g->hash_key = kmemdup(key, c->keysize, GFP_KERNEL);
 456         if (!g->hash_key) {
 457                 kfree(g->hash_string);
 458                 return -ENOMEM;
 459         }
 460
 461         return 0;
 462 }
 463
 464 static int pohmelfs_crypto_cipher_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 465 {
 466         char *algo = (char *)c->data;
 467         u8 *key = (u8 *)(algo + c->strlen);
 468
 469         if (g->cipher_string)
 470                 return -EEXIST;
 471
 472         g->cipher_string = kstrdup(algo, GFP_KERNEL);
 473         if (!g->cipher_string)
 474                 return -ENOMEM;
 475         g->cipher_strlen = c->strlen;
 476         g->cipher_keysize = c->keysize;
 477
 478         g->cipher_key = kmemdup(key, c->keysize, GFP_KERNEL);
 479         if (!g->cipher_key) {
 480                 kfree(g->cipher_string);
 481                 return -ENOMEM;
 482         }
 483
 484         return 0;
 485 }
 486
 487 static int pohmelfs_cn_crypto(struct cn_msg *msg)
 488 {
 489         struct pohmelfs_crypto *crypto = (struct pohmelfs_crypto *)msg->data;
 490         struct pohmelfs_config_group *g;
 491         int err = 0;
 492
 493         dprintk("%s: idx: %u, strlen: %u, type: %u, keysize: %u, algo: %s.\n",
 494                         __func__, crypto->idx, crypto->strlen, crypto->type,
 495                         crypto->keysize, (char *)crypto->data);
 496
 497         mutex_lock(&pohmelfs_config_lock);
 498         g = pohmelfs_find_create_config_group(crypto->idx);
 499         if (!g) {
 500                 err = -ENOMEM;
 501                 goto out_unlock;
 502         }
 503
 504         switch (crypto->type) {
 505         case POHMELFS_CRYPTO_HASH:
 506                         err = pohmelfs_crypto_hash_init(g, crypto);
 507                         break;
 508         case POHMELFS_CRYPTO_CIPHER:
 509                         err = pohmelfs_crypto_cipher_init(g, crypto);
 510                         break;
 511         default:
 512                         err = -ENOTSUPP;
 513                         break;
 514         }
 515
 516 out_unlock:
 517         mutex_unlock(&pohmelfs_config_lock);
 518         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 519                 err = -ENOMEM;
 520
 521         return err;
 522 }
 523
 524 static void pohmelfs_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 525 {
 526         int err;
 527
 528         if (!cap_raised(current_cap(), CAP_SYS_ADMIN))
 529                 return;
 530
 531         switch (msg->flags) {
 532         case POHMELFS_FLAGS_ADD:
 533         case POHMELFS_FLAGS_DEL:
 534         case POHMELFS_FLAGS_MODIFY:
 535                         err = pohmelfs_cn_ctl(msg, msg->flags);
 536                         break;
 537         case POHMELFS_FLAGS_FLUSH:
 538                         err = pohmelfs_cn_flush(msg);
 539                         break;
 540         case POHMELFS_FLAGS_SHOW:
 541                         err = pohmelfs_cn_disp(msg);
 542                         break;
 543         case POHMELFS_FLAGS_DUMP:
 544                         err = pohmelfs_cn_dump(msg);
 545                         break;
 546         case POHMELFS_FLAGS_CRYPTO:
 547                         err = pohmelfs_cn_crypto(msg);
 548                         break;
 549         default:
 550                         err = -ENOSYS;
 551                         break;
 552         }
 553 }
 554
 555 int pohmelfs_config_check(struct pohmelfs_config *config, int idx)
 556 {
 557         struct pohmelfs_ctl *ctl = &config->state.ctl;
 558         struct pohmelfs_config *tmp;
 559         int err = -ENOENT;
 560         struct pohmelfs_ctl *sc;
 561         struct pohmelfs_config_group *g;
 562
 563         mutex_lock(&pohmelfs_config_lock);
 564
 565         g = pohmelfs_find_config_group(ctl->idx);
 566         if (g) {
 567                 list_for_each_entry(tmp, &g->config_list, config_entry) {
 568                         sc = &tmp->state.ctl;
 569
 570                         if (pohmelfs_config_eql(sc, ctl)) {
 571                                 err = 0;
 572                                 break;
 573                         }
 574                 }
 575         }
 576
 577         mutex_unlock(&pohmelfs_config_lock);
 578
 579         return err;
 580 }
 581
 582 int __init pohmelfs_config_init(void)
 583 {
 584         /* XXX remove (void *) cast when vanilla connector got synced */
 585         return cn_add_callback(&pohmelfs_cn_id, "pohmelfs", (void *)pohmelfs_cn_callback);
 586 }
 587
 588 void pohmelfs_config_exit(void)
 589 {
 590         struct pohmelfs_config *c, *tmp;
 591         struct pohmelfs_config_group *g, *gtmp;
 592
 593         cn_del_callback(&pohmelfs_cn_id);
 594
 595         mutex_lock(&pohmelfs_config_lock);
 596         list_for_each_entry_safe(g, gtmp, &pohmelfs_config_list, group_entry) {
 597                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 598                         list_del(&c->config_entry);
 599                         kfree(c);
 600                 }
 601
 602                 list_del(&g->group_entry);
 603
 604                 kfree(g->hash_string);
 605
 606                 kfree(g->cipher_string);
 607
 608                 kfree(g);
 609         }
 610         mutex_unlock(&pohmelfs_config_lock);
 611 }