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_modify_config(struct pohmelfs_ctl *old, struct pohmelfs_ctl *new)
 293 {
 294         old->perm = new->perm;
 295         old->prio = new->prio;
 296         return 0;
 297 }
 298
 299 static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 300 {
 301         struct pohmelfs_config_group *g;
 302         struct pohmelfs_ctl *ctl = (struct pohmelfs_ctl *)msg->data;
 303         struct pohmelfs_config *c, *tmp;
 304         int err = 0;
 305
 306         if (msg->len != sizeof(struct pohmelfs_ctl))
 307                 return -EBADMSG;
 308
 309         mutex_lock(&pohmelfs_config_lock);
 310
 311         g = pohmelfs_find_create_config_group(ctl->idx);
 312         if (!g) {
 313                 err = -ENOMEM;
 314                 goto out_unlock;
 315         }
 316
 317         list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 318                 struct pohmelfs_ctl *sc = &c->state.ctl;
 319
 320                 if (pohmelfs_config_eql(sc, ctl)) {
 321                         if (action == POHMELFS_FLAGS_ADD) {
 322                                 err = -EEXIST;
 323                                 goto out_unlock;
 324                         } else if (action == POHMELFS_FLAGS_DEL) {
 325                                 list_del(&c->config_entry);
 326                                 g->num_entry--;
 327                                 kfree(c);
 328                                 goto out_unlock;
 329                         } else if (action == POHMELFS_FLAGS_MODIFY) {
 330                                 err = pohmelfs_modify_config(sc, ctl);
 331                                 goto out_unlock;
 332                         } else {
 333                                 err = -EEXIST;
 334                                 goto out_unlock;
 335                         }
 336                 }
 337         }
 338         if (action == POHMELFS_FLAGS_DEL) {
 339                 err = -EBADMSG;
 340                 goto out_unlock;
 341         }
 342
 343         c = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
 344         if (!c) {
 345                 err = -ENOMEM;
 346                 goto out_unlock;
 347         }
 348         memcpy(&c->state.ctl, ctl, sizeof(struct pohmelfs_ctl));
 349         g->num_entry++;
 350
 351         list_add_tail(&c->config_entry, &g->config_list);
 352
 353 out_unlock:
 354         mutex_unlock(&pohmelfs_config_lock);
 355         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 356                 err = -ENOMEM;
 357
 358         return err;
 359 }
 360
 361 static int pohmelfs_crypto_hash_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 362 {
 363         char *algo = (char *)c->data;
 364         u8 *key = (u8 *)(algo + c->strlen);
 365
 366         if (g->hash_string)
 367                 return -EEXIST;
 368
 369         g->hash_string = kstrdup(algo, GFP_KERNEL);
 370         if (!g->hash_string)
 371                 return -ENOMEM;
 372         g->hash_strlen = c->strlen;
 373         g->hash_keysize = c->keysize;
 374
 375         g->hash_key = kmalloc(c->keysize, GFP_KERNEL);
 376         if (!g->hash_key) {
 377                 kfree(g->hash_string);
 378                 return -ENOMEM;
 379         }
 380
 381         memcpy(g->hash_key, key, c->keysize);
 382
 383         return 0;
 384 }
 385
 386 static int pohmelfs_crypto_cipher_init(struct pohmelfs_config_group *g, struct pohmelfs_crypto *c)
 387 {
 388         char *algo = (char *)c->data;
 389         u8 *key = (u8 *)(algo + c->strlen);
 390
 391         if (g->cipher_string)
 392                 return -EEXIST;
 393
 394         g->cipher_string = kstrdup(algo, GFP_KERNEL);
 395         if (!g->cipher_string)
 396                 return -ENOMEM;
 397         g->cipher_strlen = c->strlen;
 398         g->cipher_keysize = c->keysize;
 399
 400         g->cipher_key = kmalloc(c->keysize, GFP_KERNEL);
 401         if (!g->cipher_key) {
 402                 kfree(g->cipher_string);
 403                 return -ENOMEM;
 404         }
 405
 406         memcpy(g->cipher_key, key, c->keysize);
 407
 408         return 0;
 409 }
 410
 411
 412 static int pohmelfs_cn_crypto(struct cn_msg *msg)
 413 {
 414         struct pohmelfs_crypto *crypto = (struct pohmelfs_crypto *)msg->data;
 415         struct pohmelfs_config_group *g;
 416         int err = 0;
 417
 418         dprintk("%s: idx: %u, strlen: %u, type: %u, keysize: %u, algo: %s.\n",
 419                         __func__, crypto->idx, crypto->strlen, crypto->type,
 420                         crypto->keysize, (char *)crypto->data);
 421
 422         mutex_lock(&pohmelfs_config_lock);
 423         g = pohmelfs_find_create_config_group(crypto->idx);
 424         if (!g) {
 425                 err = -ENOMEM;
 426                 goto out_unlock;
 427         }
 428
 429         switch (crypto->type) {
 430                 case POHMELFS_CRYPTO_HASH:
 431                         err = pohmelfs_crypto_hash_init(g, crypto);
 432                         break;
 433                 case POHMELFS_CRYPTO_CIPHER:
 434                         err = pohmelfs_crypto_cipher_init(g, crypto);
 435                         break;
 436                 default:
 437                         err = -ENOTSUPP;
 438                         break;
 439         }
 440
 441 out_unlock:
 442         mutex_unlock(&pohmelfs_config_lock);
 443         if (pohmelfs_send_reply(err, 0, POHMELFS_NOINFO_ACK, msg, NULL))
 444                 err = -ENOMEM;
 445
 446         return err;
 447 }
 448
 449 static void pohmelfs_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 450 {
 451         int err;
 452
 453         switch (msg->flags) {
 454                 case POHMELFS_FLAGS_ADD:
 455                 case POHMELFS_FLAGS_DEL:
 456                 case POHMELFS_FLAGS_MODIFY:
 457                         err = pohmelfs_cn_ctl(msg, msg->flags);
 458                         break;
 459                 case POHMELFS_FLAGS_SHOW:
 460                         err = pohmelfs_cn_disp(msg);
 461                         break;
 462                 case POHMELFS_FLAGS_CRYPTO:
 463                         err = pohmelfs_cn_crypto(msg);
 464                         break;
 465                 default:
 466                         err = -ENOSYS;
 467                         break;
 468         }
 469 }
 470
 471 int pohmelfs_config_check(struct pohmelfs_config *config, int idx)
 472 {
 473         struct pohmelfs_ctl *ctl = &config->state.ctl;
 474         struct pohmelfs_config *tmp;
 475         int err = -ENOENT;
 476         struct pohmelfs_ctl *sc;
 477         struct pohmelfs_config_group *g;
 478
 479         mutex_lock(&pohmelfs_config_lock);
 480
 481         g = pohmelfs_find_config_group(ctl->idx);
 482         if (g) {
 483                 list_for_each_entry(tmp, &g->config_list, config_entry) {
 484                         sc = &tmp->state.ctl;
 485
 486                         if (pohmelfs_config_eql(sc, ctl)) {
 487                                 err = 0;
 488                                 break;
 489                         }
 490                 }
 491         }
 492
 493         mutex_unlock(&pohmelfs_config_lock);
 494
 495         return err;
 496 }
 497
 498 int __init pohmelfs_config_init(void)
 499 {
 500         return cn_add_callback(&pohmelfs_cn_id, "pohmelfs", pohmelfs_cn_callback);
 501 }
 502
 503 void pohmelfs_config_exit(void)
 504 {
 505         struct pohmelfs_config *c, *tmp;
 506         struct pohmelfs_config_group *g, *gtmp;
 507
 508         cn_del_callback(&pohmelfs_cn_id);
 509
 510         mutex_lock(&pohmelfs_config_lock);
 511         list_for_each_entry_safe(g, gtmp, &pohmelfs_config_list, group_entry) {
 512                 list_for_each_entry_safe(c, tmp, &g->config_list, config_entry) {
 513                         list_del(&c->config_entry);
 514                         kfree(c);
 515                 }
 516
 517                 list_del(&g->group_entry);
 518
 519                 if (g->hash_string)
 520                         kfree(g->hash_string);
 521
 522                 if (g->cipher_string)
 523                         kfree(g->cipher_string);
 524
 525                 kfree(g);
 526         }
 527         mutex_unlock(&pohmelfs_config_lock);
 528 }