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
  24 #include "netfs.h"
  25
  26 /*
  27  * Global configuration list.
  28  * Each client can be asked to get one of them.
  29  *
  30  * Allows to provide remote server address (ipv4/v6/whatever), port
  31  * and so on via kernel connector.
  32  */
  33
  34 static struct cb_id pohmelfs_cn_id = {.idx = POHMELFS_CN_IDX, .val = POHMELFS_CN_VAL};
  35 static LIST_HEAD(pohmelfs_config_list);
  36 static DEFINE_MUTEX(pohmelfs_config_lock);
  37
  38 static inline int pohmelfs_config_eql(struct pohmelfs_ctl *sc, struct pohmelfs_ctl *ctl)
  39 {
  40         if (sc->idx == ctl->idx && sc->type == ctl->type &&
  41                         sc->proto == ctl->proto &&
  42                         sc->addrlen == ctl->addrlen &&
  43                         !memcmp(&sc->addr, &ctl->addr, ctl->addrlen))
  44                 return 1;
  45
  46         return 0;
  47 }
  48
  49 static struct pohmelfs_config_group *pohmelfs_find_config_group(unsigned int idx)
  50 {
  51         struct pohmelfs_config_group *g, *group = NULL;
  52
  53         list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
  54                 if (g->idx == idx) {
  55                         group = g;
  56                         break;
  57                 }
  58         }
  59
  60         return group;
  61 }
  62
  63 static struct pohmelfs_config_group *pohmelfs_find_create_config_group(unsigned int idx)
  64 {
  65         struct pohmelfs_config_group *g;
  66
  67         g = pohmelfs_find_config_group(idx);
  68         if (g)
  69                 return g;
  70
  71         g = kzalloc(sizeof(struct pohmelfs_config_group), GFP_KERNEL);
  72         if (!g)
  73                 return NULL;
  74
  75         INIT_LIST_HEAD(&g->config_list);
  76         g->idx = idx;
  77         g->num_entry = 0;
  78
  79         list_add_tail(&g->group_entry, &pohmelfs_config_list);
  80
  81         return g;
  82 }
  83
  84 static inline void pohmelfs_insert_config_entry(struct pohmelfs_sb *psb, struct pohmelfs_config *dst)
  85 {
  86         struct pohmelfs_config *tmp;
  87
  88         INIT_LIST_HEAD(&dst->config_entry);
  89
  90         list_for_each_entry(tmp, &psb->state_list, config_entry) {
  91                 if (dst->state.ctl.prio > tmp->state.ctl.prio)
  92                         list_add_tail(&dst->config_entry, &tmp->config_entry);
  93         }
  94         if (list_empty(&dst->config_entry))
  95                 list_add_tail(&dst->config_entry, &psb->state_list);
  96 }
  97
  98 static int pohmelfs_move_config_entry(struct pohmelfs_sb *psb,
  99                 struct pohmelfs_config *dst, struct pohmelfs_config *new)
 100 {
 101         if ((dst->state.ctl.prio == new->state.ctl.prio) &&
 102                 (dst->state.ctl.perm == new->state.ctl.perm))
 103                 return 0;
 104
 105         dprintk("%s: dst: prio: %d, perm: %x, new: prio: %d, perm: %d.\n",
 106                         __func__, dst->state.ctl.prio, dst->state.ctl.perm,
 107                         new->state.ctl.prio, new->state.ctl.perm);
 108         dst->state.ctl.prio = new->state.ctl.prio;
 109         dst->state.ctl.perm = new->state.ctl.perm;
 110
 111         list_del_init(&dst->config_entry);
 112         pohmelfs_insert_config_entry(psb, dst);
 113         return 0;
 114 }
 115
 116 /*
 117  * pohmelfs_copy_config() is used to copy new state configs from the
 118  * config group (controlled by the netlink messages) into the superblock.
 119  * This happens either at startup time where no transactions can access
 120  * the list of the configs (and thus list of the network states), or at
 121  * run-time, where it is protected by the psb->state_lock.
 122  */
 123 int pohmelfs_copy_config(struct pohmelfs_sb *psb)
 124 {
 125         struct pohmelfs_config_group *g;
 126         struct pohmelfs_config *c, *dst;
 127         int err = -ENODEV;
 128
 129         mutex_lock(&pohmelfs_config_lock);
 130
 131         g = pohmelfs_find_config_group(psb->idx);
 132         if (!g)
 133                 goto out_unlock;
 134
 135         /*
 136          * Run over all entries in given config group and try to crate and
 137          * initialize those, which do not exist in superblock list.
 138          * Skip all existing entries.
 139          */
 140
 141         list_for_each_entry(c, &g->config_list, config_entry) {
 142                 err = 0;
 143                 list_for_each_entry(dst, &psb->state_list, config_entry) {
 144                         if (pohmelfs_config_eql(&dst->state.ctl, &c->state.ctl)) {
 145                                 err = pohmelfs_move_config_entry(psb, dst, c);
 146                                 if (!err)
 147                                         err = -EEXIST;
 148                                 break;
 149                         }
 150                 }
 151
 152                 if (err)
 153                         continue;
 154
 155                 dst = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
 156                 if (!dst) {
 157                         err = -ENOMEM;
 158                         break;
 159                 }
 160
 161                 memcpy(&dst->state.ctl, &c->state.ctl, sizeof(struct pohmelfs_ctl));
 162
 163                 pohmelfs_insert_config_entry(psb, dst);
 164
 165                 err = pohmelfs_state_init_one(psb, dst);
 166                 if (err) {
 167                         list_del(&dst->config_entry);
 168                         kfree(dst);
 169                 }
 170
 171                 err = 0;
 172         }
 173
 174 out_unlock:
 175         mutex_unlock(&pohmelfs_config_lock);
 176
 177         return err;
 178 }
 179
 180 int pohmelfs_copy_crypto(struct pohmelfs_sb *psb)
 181 {
 182         struct pohmelfs_config_group *g;
 183         int err = -ENOENT;
 184
 185         mutex_lock(&pohmelfs_config_lock);
 186         g = pohmelfs_find_config_group(psb->idx);
 187         if (!g)
 188                 goto err_out_exit;
 189
 190         if (g->hash_string) {
 191                 err = -ENOMEM;
 192                 psb->hash_string = kstrdup(g->hash_string, GFP_KERNEL);
 193                 if (!psb->hash_string)
 194                         goto err_out_exit;
 195                 psb->hash_strlen = g->hash_strlen;
 196         }
 197
 198         if (g->cipher_string) {
 199                 psb->cipher_string = kstrdup(g->cipher_string, GFP_KERNEL);
 200                 if (!psb->cipher_string)
 201                         goto err_out_free_hash_string;
 202                 psb->cipher_strlen = g->cipher_strlen;
 203         }
 204
 205         if (g->hash_keysize) {
 206                 psb->hash_key = kmalloc(g->hash_keysize, GFP_KERNEL);
 207                 if (!psb->hash_key)
 208                         goto err_out_free_cipher_string;
 209                 memcpy(psb->hash_key, g->hash_key, g->hash_keysize);
 210                 psb->hash_keysize = g->hash_keysize;
 211         }
 212
 213         if (g->cipher_keysize) {
 214                 psb->cipher_key = kmalloc(g->cipher_keysize, GFP_KERNEL);
 215                 if (!psb->cipher_key)
 216                         goto err_out_free_hash;
 217                 memcpy(psb->cipher_key, g->cipher_key, g->cipher_keysize);
 218                 psb->cipher_keysize = g->cipher_keysize;
 219         }
 220
 221         mutex_unlock(&pohmelfs_config_lock);
 222
 223         return 0;
 224
 225 err_out_free_hash:
 226         kfree(psb->hash_key);
 227 err_out_free_cipher_string:
 228         kfree(psb->cipher_string);
 229 err_out_free_hash_string:
 230         kfree(psb->hash_string);
 231 err_out_exit:
 232         mutex_unlock(&pohmelfs_config_lock);
 233         return err;
 234 }
 235
 236 static int pohmelfs_send_reply(int err, int msg_num, int action, struct cn_msg *msg, struct pohmelfs_ctl *ctl)
 237 {
 238         struct pohmelfs_cn_ack *ack;
 239
 240         ack = kmalloc(sizeof(struct pohmelfs_cn_ack), GFP_KERNEL);
 241         if (!ack)
 242                 return -ENOMEM;
 243
 244         memset(ack, 0, sizeof(struct pohmelfs_cn_ack));
 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                 if (g)
 306                         total_msg += g->num_entry;
 307         }
 308         if (total_msg == 0) {
 309                 if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 310                         err = -ENOMEM;
 311                 goto out_unlock;
 312         }
 313
 314         list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
 315                 if (g) {
 316                         list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 317                                 struct pohmelfs_ctl *sc = &c->state.ctl;
 318                                 if (pohmelfs_send_reply(err, total_msg - i, POHMELFS_CTLINFO_ACK, msg, sc)) {
 319                                         err = -ENOMEM;
 320                                         goto out_unlock;
 321                                 }
 322                                 i += 1;
 323                         }
 324                 }
 325         }
 326
 327 out_unlock:
 328         mutex_unlock(&pohmelfs_config_lock);
 329         return err;
 330 }
 331
 332 static int pohmelfs_cn_flush(struct cn_msg *msg)
 333 {
 334         struct pohmelfs_config_group *g;
 335         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 336         struct pohmelfs_config *c, *tmp;
 337         int err = 0;
 338
 339         if (msg->len != sizeof(struct pohmelfs_ctl))
 340                 return -EBADMSG;
 341
 342         mutex_lock(&pohmelfs_config_lock);
 343
 344         if (ctl->idx != POHMELFS_NULL_IDX) {
 345                 g = pohmelfs_find_config_group(ctl->idx);
 346
 347                 if (!g)
 348                         goto out_unlock;
 349
 350                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 351                         list_del(&c->config_entry);
 352                         g->num_entry--;
 353                         kfree(c);
 354                 }
 355         } else {
 356                 list_for_each_entry(g, &pohmelfs_config_list, group_entry) {
 357                         if (g) {
 358                                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 359                                         list_del(&c->config_entry);
 360                                         g->num_entry--;
 361                                         kfree(c);
 362                                 }
 363                         }
 364                 }
 365         }
 366
 367 out_unlock:
 368         mutex_unlock(&pohmelfs_config_lock);
 369         pohmelfs_cn_dump(msg);
 370
 371         return err;
 372 }
 373
 374 static int pohmelfs_modify_config(struct pohmelfs_ctl *old, struct pohmelfs_ctl *new)
 375 {
 376         old->perm = new->perm;
 377         old->prio = new->prio;
 378         return 0;
 379 }
 380
 381 static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 382 {
 383         struct pohmelfs_config_group *g;
 384         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 385         struct pohmelfs_config *c, *tmp;
 386         int err = 0;
 387
 388         if (msg->len != sizeof(struct pohmelfs_ctl))
 389                 return -EBADMSG;
 390
 391         mutex_lock(&pohmelfs_config_lock);
 392
 393         g = pohmelfs_find_create_config_group(ctl->idx);
 394         if (!g) {
 395                 err = -ENOMEM;
 396                 goto out_unlock;
 397         }
 398
 399         list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 400                 struct pohmelfs_ctl *sc = &c->state.ctl;
 401
 402                 if (pohmelfs_config_eql(sc, ctl)) {
 403                         if (action == POHMELFS_FLAGS_ADD) {
 404                                 err = -EEXIST;
 405                                 goto out_unlock;
 406                         } else if (action == POHMELFS_FLAGS_DEL) {
 407                                 list_del(&c->config_entry);
 408                                 g->num_entry--;
 409                                 kfree(c);
 410                                 goto out_unlock;
 411                         } else if (action == POHMELFS_FLAGS_MODIFY) {
 412                                 err = pohmelfs_modify_config(sc, ctl);
 413                                 goto out_unlock;
 414                         } else {
 415                                 err = -EEXIST;
 416                                 goto out_unlock;
 417                         }
 418                 }
 419         }
 420         if (action == POHMELFS_FLAGS_DEL) {
 421                 err = -EBADMSG;
 422                 goto out_unlock;
 423         }
 424
 425         c = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
 426         if (!c) {
 427                 err = -ENOMEM;
 428                 goto out_unlock;
 429         }
 430         memcpy(&c->state.ctl, ctl, sizeof(struct pohmelfs_ctl));
 431         g->num_entry++;
 432
 433         list_add_tail(&c->config_entry, &g->config_list);
 434
 435  out_unlock:
 436         mutex_unlock(&pohmelfs_config_lock);
 437         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 438                 err = -ENOMEM;
 439
 440         return err;
 441 }
 442
 443 static int pohmelfs_crypto_hash_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 444 {
 445         char *algo = (char *)c->data;
 446         u8 *key = (u8 *)(algo + c->strlen);
 447
 448         if (g->hash_string)
 449                 return -EEXIST;
 450
 451         g->hash_string = kstrdup(algo, GFP_KERNEL);
 452         if (!g->hash_string)
 453                 return -ENOMEM;
 454         g->hash_strlen = c->strlen;
 455         g->hash_keysize = c->keysize;
 456
 457         g->hash_key = kmalloc(c->keysize, GFP_KERNEL);
 458         if (!g->hash_key) {
 459                 kfree(g->hash_string);
 460                 return -ENOMEM;
 461         }
 462
 463         memcpy(g->hash_key, key, c->keysize);
 464
 465         return 0;
 466 }
 467
 468 static int pohmelfs_crypto_cipher_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 469 {
 470         char *algo = (char *)c->data;
 471         u8 *key = (u8 *)(algo + c->strlen);
 472
 473         if (g->cipher_string)
 474                 return -EEXIST;
 475
 476         g->cipher_string = kstrdup(algo, GFP_KERNEL);
 477         if (!g->cipher_string)
 478                 return -ENOMEM;
 479         g->cipher_strlen = c->strlen;
 480         g->cipher_keysize = c->keysize;
 481
 482         g->cipher_key = kmalloc(c->keysize, GFP_KERNEL);
 483         if (!g->cipher_key) {
 484                 kfree(g->cipher_string);
 485                 return -ENOMEM;
 486         }
 487
 488         memcpy(g->cipher_key, key, c->keysize);
 489
 490         return 0;
 491 }
 492
 493 static int pohmelfs_cn_crypto(struct cn_msg *msg)
 494 {
 495         struct pohmelfs_crypto *crypto = (struct pohmelfs_crypto *)msg->data;
 496         struct pohmelfs_config_group *g;
 497         int err = 0;
 498
 499         dprintk("%s: idx: %u, strlen: %u, type: %u, keysize: %u, algo: %s.\n",
 500                         __func__, crypto->idx, crypto->strlen, crypto->type,
 501                         crypto->keysize, (char *)crypto->data);
 502
 503         mutex_lock(&pohmelfs_config_lock);
 504         g = pohmelfs_find_create_config_group(crypto->idx);
 505         if (!g) {
 506                 err = -ENOMEM;
 507                 goto out_unlock;
 508         }
 509
 510         switch (crypto->type) {
 511                 case POHMELFS_CRYPTO_HASH:
 512                         err = pohmelfs_crypto_hash_init(g, crypto);
 513                         break;
 514                 case POHMELFS_CRYPTO_CIPHER:
 515                         err = pohmelfs_crypto_cipher_init(g, crypto);
 516                         break;
 517                 default:
 518                         err = -ENOTSUPP;
 519                         break;
 520         }
 521
 522 out_unlock:
 523         mutex_unlock(&pohmelfs_config_lock);
 524         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 525                 err = -ENOMEM;
 526
 527         return err;
 528 }
 529
 530 static void pohmelfs_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 531 {
 532         int err;
 533
 534         if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN))
 535                 return;
 536
 537         switch (msg->flags) {
 538                 case POHMELFS_FLAGS_ADD:
 539                 case POHMELFS_FLAGS_DEL:
 540                 case POHMELFS_FLAGS_MODIFY:
 541                         err = pohmelfs_cn_ctl(msg, msg->flags);
 542                         break;
 543                 case POHMELFS_FLAGS_FLUSH:
 544                         err = pohmelfs_cn_flush(msg);
 545                         break;
 546                 case POHMELFS_FLAGS_SHOW:
 547                         err = pohmelfs_cn_disp(msg);
 548                         break;
 549                 case POHMELFS_FLAGS_DUMP:
 550                         err = pohmelfs_cn_dump(msg);
 551                         break;
 552                 case POHMELFS_FLAGS_CRYPTO:
 553                         err = pohmelfs_cn_crypto(msg);
 554                         break;
 555                 default:
 556                         err = -ENOSYS;
 557                         break;
 558         }
 559 }
 560
 561 int pohmelfs_config_check(struct pohmelfs_config *config, int idx)
 562 {
 563         struct pohmelfs_ctl *ctl = &config->state.ctl;
 564         struct pohmelfs_config *tmp;
 565         int err = -ENOENT;
 566         struct pohmelfs_ctl *sc;
 567         struct pohmelfs_config_group *g;
 568
 569         mutex_lock(&pohmelfs_config_lock);
 570
 571         g = pohmelfs_find_config_group(ctl->idx);
 572         if (g) {
 573                 list_for_each_entry(tmp, &g->config_list, config_entry) {
 574                         sc = &tmp->state.ctl;
 575
 576                         if (pohmelfs_config_eql(sc, ctl)) {
 577                                 err = 0;
 578                                 break;
 579                         }
 580                 }
 581         }
 582
 583         mutex_unlock(&pohmelfs_config_lock);
 584
 585         return err;
 586 }
 587
 588 int __init pohmelfs_config_init(void)
 589 {
 590         /* XXX remove (void *) cast when vanilla connector got synced */
 591         return cn_add_callback(&pohmelfs_cn_id, "pohmelfs", (void *)pohmelfs_cn_callback);
 592 }
 593
 594 void pohmelfs_config_exit(void)
 595 {
 596         struct pohmelfs_config *c, *tmp;
 597         struct pohmelfs_config_group *g, *gtmp;
 598
 599         cn_del_callback(&pohmelfs_cn_id);
 600
 601         mutex_lock(&pohmelfs_config_lock);
 602         list_for_each_entry_safe(g, gtmp, &pohmelfs_config_list, group_entry) {
 603                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 604                         list_del(&c->config_entry);
 605                         kfree(c);
 606                 }
 607
 608                 list_del(&g->group_entry);
 609
 610                 if (g->hash_string)
 611                         kfree(g->hash_string);
 612
 613                 if (g->cipher_string)
 614                         kfree(g->cipher_string);
 615
 616                 kfree(g);
 617         }
 618         mutex_unlock(&pohmelfs_config_lock);
 619 }