history.c

   1 /*
   2  * libuci - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 /*
  16  * This file contains the code for handling uci config history files
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <sys/file.h>
  23 #include <stdbool.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <stdio.h>
  27 #include <ctype.h>
  28
  29 /* record a change that was done to a package */
  30 void
  31 uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value)
  32 {
  33         struct uci_history *h;
  34         int size = strlen(section) + 1;
  35         char *ptr;
  36
  37         if (value)
  38                 size += strlen(value) + 1;
  39
  40         h = uci_alloc_element(ctx, history, option, size);
  41         ptr = uci_dataptr(h);
  42         h->cmd = cmd;
  43         h->section = strcpy(ptr, section);
  44         if (value) {
  45                 ptr += strlen(ptr) + 1;
  46                 h->value = strcpy(ptr, value);
  47         }
  48         uci_list_add(list, &h->e.list);
  49 }
  50
  51 void
  52 uci_free_history(struct uci_history *h)
  53 {
  54         if (!h)
  55                 return;
  56         if ((h->section != NULL) &&
  57                 (h->section != uci_dataptr(h))) {
  58                 free(h->section);
  59                 free(h->value);
  60         }
  61         uci_free_element(&h->e);
  62 }
  63
  64
  65 int uci_set_savedir(struct uci_context *ctx, const char *dir)
  66 {
  67         char *sdir;
  68
  69         UCI_HANDLE_ERR(ctx);
  70         UCI_ASSERT(ctx, dir != NULL);
  71
  72         sdir = uci_strdup(ctx, dir);
  73         if (ctx->savedir != uci_savedir)
  74                 free(ctx->savedir);
  75         ctx->savedir = sdir;
  76         return 0;
  77 }
  78
  79 int uci_add_history_path(struct uci_context *ctx, const char *dir)
  80 {
  81         struct uci_element *e;
  82
  83         UCI_HANDLE_ERR(ctx);
  84         UCI_ASSERT(ctx, dir != NULL);
  85         e = uci_alloc_generic(ctx, UCI_TYPE_PATH, dir, sizeof(struct uci_element));
  86         uci_list_add(&ctx->history_path, &e->list);
  87
  88         return 0;
  89 }
  90
  91 static inline int uci_parse_history_tuple(struct uci_context *ctx, char **buf, struct uci_ptr *ptr)
  92 {
  93         int c = UCI_CMD_CHANGE;
  94
  95         switch(**buf) {
  96         case '^':
  97                 c = UCI_CMD_REORDER;
  98                 break;
  99         case '-':
 100                 c = UCI_CMD_REMOVE;
 101                 break;
 102         case '@':
 103                 c = UCI_CMD_RENAME;
 104                 break;
 105         case '+':
 106                 /* UCI_CMD_ADD is used for anonymous sections or list values */
 107                 c = UCI_CMD_ADD;
 108                 break;
 109         case '|':
 110                 c = UCI_CMD_LIST_ADD;
 111                 break;
 112         }
 113
 114         if (c != UCI_CMD_CHANGE)
 115                 *buf += 1;
 116
 117         UCI_INTERNAL(uci_parse_ptr, ctx, ptr, *buf);
 118
 119         if (!ptr->section)
 120                 goto error;
 121         if (ptr->flags & UCI_LOOKUP_EXTENDED)
 122                 goto error;
 123
 124         switch(c) {
 125         case UCI_CMD_REORDER:
 126                 if (!ptr->value || ptr->option)
 127                         goto error;
 128                 break;
 129         case UCI_CMD_RENAME:
 130                 if (!ptr->value || !uci_validate_name(ptr->value))
 131                         goto error;
 132                 break;
 133         case UCI_CMD_LIST_ADD:
 134                 if (!ptr->option)
 135                         goto error;
 136         }
 137
 138         return c;
 139
 140 error:
 141         UCI_THROW(ctx, UCI_ERR_INVAL);
 142         return 0;
 143 }
 144
 145 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
 146 {
 147         struct uci_element *e = NULL;
 148         struct uci_ptr ptr;
 149         int cmd;
 150
 151         cmd = uci_parse_history_tuple(ctx, &buf, &ptr);
 152         if (strcmp(ptr.package, p->e.name) != 0)
 153                 goto error;
 154
 155         if (ctx->flags & UCI_FLAG_SAVED_HISTORY)
 156                 uci_add_history(ctx, &p->saved_history, cmd, ptr.section, ptr.option, ptr.value);
 157
 158         switch(cmd) {
 159         case UCI_CMD_REORDER:
 160                 expand_ptr(ctx, &ptr, true);
 161                 if (!ptr.s)
 162                         UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 163                 UCI_INTERNAL(uci_reorder_section, ctx, ptr.s, strtoul(ptr.value, NULL, 10));
 164                 break;
 165         case UCI_CMD_RENAME:
 166                 UCI_INTERNAL(uci_rename, ctx, &ptr);
 167                 break;
 168         case UCI_CMD_REMOVE:
 169                 UCI_INTERNAL(uci_delete, ctx, &ptr);
 170                 break;
 171         case UCI_CMD_LIST_ADD:
 172                 UCI_INTERNAL(uci_add_list, ctx, &ptr);
 173                 break;
 174         case UCI_CMD_ADD:
 175         case UCI_CMD_CHANGE:
 176                 UCI_INTERNAL(uci_set, ctx, &ptr);
 177                 e = ptr.last;
 178                 if (!ptr.option && e && (cmd == UCI_CMD_ADD))
 179                         uci_to_section(e)->anonymous = true;
 180                 break;
 181         }
 182         return;
 183 error:
 184         UCI_THROW(ctx, UCI_ERR_PARSE);
 185 }
 186
 187 /* returns the number of changes that were successfully parsed */
 188 static int uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
 189 {
 190         struct uci_parse_context *pctx;
 191         int changes = 0;
 192
 193         /* make sure no memory from previous parse attempts is leaked */
 194         uci_cleanup(ctx);
 195
 196         pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
 197         ctx->pctx = pctx;
 198         pctx->file = stream;
 199
 200         while (!feof(pctx->file)) {
 201                 uci_getln(ctx, 0);
 202                 if (!pctx->buf[0])
 203                         continue;
 204
 205                 /*
 206                  * ignore parse errors in single lines, we want to preserve as much
 207                  * history as possible
 208                  */
 209                 UCI_TRAP_SAVE(ctx, error);
 210                 uci_parse_history_line(ctx, p, pctx->buf);
 211                 UCI_TRAP_RESTORE(ctx);
 212                 changes++;
 213 error:
 214                 continue;
 215         }
 216
 217         /* no error happened, we can get rid of the parser context now */
 218         uci_cleanup(ctx);
 219         return changes;
 220 }
 221
 222 /* returns the number of changes that were successfully parsed */
 223 static int uci_load_history_file(struct uci_context *ctx, struct uci_package *p, char *filename, FILE **f, bool flush)
 224 {
 225         FILE *stream = NULL;
 226         int changes = 0;
 227
 228         UCI_TRAP_SAVE(ctx, done);
 229         stream = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
 230         if (p)
 231                 changes = uci_parse_history(ctx, stream, p);
 232         UCI_TRAP_RESTORE(ctx);
 233 done:
 234         if (f)
 235                 *f = stream;
 236         else if (stream)
 237                 uci_close_stream(stream);
 238         return changes;
 239 }
 240
 241 /* returns the number of changes that were successfully parsed */
 242 static int uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
 243 {
 244         struct uci_element *e;
 245         char *filename = NULL;
 246         FILE *f = NULL;
 247         int changes = 0;
 248
 249         if (!p->has_history)
 250                 return 0;
 251
 252         uci_foreach_element(&ctx->history_path, e) {
 253                 if ((asprintf(&filename, "%s/%s", e->name, p->e.name) < 0) || !filename)
 254                         UCI_THROW(ctx, UCI_ERR_MEM);
 255
 256                 uci_load_history_file(ctx, p, filename, NULL, false);
 257                 free(filename);
 258         }
 259
 260         if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
 261                 UCI_THROW(ctx, UCI_ERR_MEM);
 262
 263         changes = uci_load_history_file(ctx, p, filename, &f, flush);
 264         if (flush && f && (changes > 0)) {
 265                 rewind(f);
 266                 if (ftruncate(fileno(f), 0) < 0) {
 267                         uci_close_stream(f);
 268                         UCI_THROW(ctx, UCI_ERR_IO);
 269                 }
 270         }
 271         if (filename)
 272                 free(filename);
 273         uci_close_stream(f);
 274         ctx->err = 0;
 275         return changes;
 276 }
 277
 278 static void uci_filter_history(struct uci_context *ctx, const char *name, const char *section, const char *option)
 279 {
 280         struct uci_parse_context *pctx;
 281         struct uci_element *e, *tmp;
 282         struct uci_list list;
 283         char *filename = NULL;
 284         struct uci_ptr ptr;
 285         FILE *f = NULL;
 286
 287         uci_list_init(&list);
 288         uci_alloc_parse_context(ctx);
 289         pctx = ctx->pctx;
 290
 291         if ((asprintf(&filename, "%s/%s", ctx->savedir, name) < 0) || !filename)
 292                 UCI_THROW(ctx, UCI_ERR_MEM);
 293
 294         UCI_TRAP_SAVE(ctx, done);
 295         f = uci_open_stream(ctx, filename, SEEK_SET, true, false);
 296         pctx->file = f;
 297         while (!feof(f)) {
 298                 struct uci_element *e;
 299                 char *buf;
 300
 301                 uci_getln(ctx, 0);
 302                 buf = pctx->buf;
 303                 if (!buf[0])
 304                         continue;
 305
 306                 /* NB: need to allocate the element before the call to
 307                  * uci_parse_history_tuple, otherwise the original string
 308                  * gets modified before it is saved */
 309                 e = uci_alloc_generic(ctx, UCI_TYPE_HISTORY, pctx->buf, sizeof(struct uci_element));
 310                 uci_list_add(&list, &e->list);
 311
 312                 uci_parse_history_tuple(ctx, &buf, &ptr);
 313                 if (section) {
 314                         if (!ptr.section || (strcmp(section, ptr.section) != 0))
 315                                 continue;
 316                 }
 317                 if (option) {
 318                         if (!ptr.option || (strcmp(option, ptr.option) != 0))
 319                                 continue;
 320                 }
 321                 /* match, drop this element again */
 322                 uci_free_element(e);
 323         }
 324
 325         /* rebuild the history file */
 326         rewind(f);
 327         if (ftruncate(fileno(f), 0) < 0)
 328                 UCI_THROW(ctx, UCI_ERR_IO);
 329         uci_foreach_element_safe(&list, tmp, e) {
 330                 fprintf(f, "%s\n", e->name);
 331                 uci_free_element(e);
 332         }
 333         UCI_TRAP_RESTORE(ctx);
 334
 335 done:
 336         if (filename)
 337                 free(filename);
 338         uci_close_stream(pctx->file);
 339         uci_foreach_element_safe(&list, tmp, e) {
 340                 uci_free_element(e);
 341         }
 342         uci_cleanup(ctx);
 343 }
 344
 345 int uci_revert(struct uci_context *ctx, struct uci_ptr *ptr)
 346 {
 347         char *package = NULL;
 348         char *section = NULL;
 349         char *option = NULL;
 350
 351         UCI_HANDLE_ERR(ctx);
 352         expand_ptr(ctx, ptr, false);
 353         UCI_ASSERT(ctx, ptr->p->has_history);
 354
 355         /*
 356          * - flush unwritten changes
 357          * - save the package name
 358          * - unload the package
 359          * - filter the history
 360          * - reload the package
 361          */
 362         UCI_TRAP_SAVE(ctx, error);
 363         UCI_INTERNAL(uci_save, ctx, ptr->p);
 364
 365         /* NB: need to clone package, section and option names,
 366          * as they may get freed on uci_free_package() */
 367         package = uci_strdup(ctx, ptr->p->e.name);
 368         if (ptr->section)
 369                 section = uci_strdup(ctx, ptr->section);
 370         if (ptr->option)
 371                 option = uci_strdup(ctx, ptr->option);
 372
 373         uci_free_package(&ptr->p);
 374         uci_filter_history(ctx, package, section, option);
 375
 376         UCI_INTERNAL(uci_load, ctx, package, &ptr->p);
 377         UCI_TRAP_RESTORE(ctx);
 378         ctx->err = 0;
 379
 380 error:
 381         if (package)
 382                 free(package);
 383         if (section)
 384                 free(section);
 385         if (option)
 386                 free(option);
 387         if (ctx->err)
 388                 UCI_THROW(ctx, ctx->err);
 389         return 0;
 390 }
 391
 392 int uci_save(struct uci_context *ctx, struct uci_package *p)
 393 {
 394         FILE *f = NULL;
 395         char *filename = NULL;
 396         struct uci_element *e, *tmp;
 397         struct stat statbuf;
 398
 399         UCI_HANDLE_ERR(ctx);
 400         UCI_ASSERT(ctx, p != NULL);
 401
 402         /*
 403          * if the config file was outside of the /etc/config path,
 404          * don't save the history to a file, update the real file
 405          * directly.
 406          * does not modify the uci_package pointer
 407          */
 408         if (!p->has_history)
 409                 return uci_commit(ctx, &p, false);
 410
 411         if (uci_list_empty(&p->history))
 412                 return 0;
 413
 414         if (stat(ctx->savedir, &statbuf) < 0)
 415                 mkdir(ctx->savedir, UCI_DIRMODE);
 416         else if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
 417                 UCI_THROW(ctx, UCI_ERR_IO);
 418
 419         if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
 420                 UCI_THROW(ctx, UCI_ERR_MEM);
 421
 422         uci_foreach_element(&ctx->hooks, tmp) {
 423                 struct uci_hook *hook = uci_to_hook(tmp);
 424
 425                 if (!hook->ops->set)
 426                         continue;
 427
 428                 uci_foreach_element(&p->history, e) {
 429                         hook->ops->set(hook->ops, p, uci_to_history(e));
 430                 }
 431         }
 432
 433         ctx->err = 0;
 434         UCI_TRAP_SAVE(ctx, done);
 435         f = uci_open_stream(ctx, filename, SEEK_END, true, true);
 436         UCI_TRAP_RESTORE(ctx);
 437
 438         uci_foreach_element_safe(&p->history, tmp, e) {
 439                 struct uci_history *h = uci_to_history(e);
 440                 char *prefix = "";
 441
 442                 switch(h->cmd) {
 443                 case UCI_CMD_REMOVE:
 444                         prefix = "-";
 445                         break;
 446                 case UCI_CMD_RENAME:
 447                         prefix = "@";
 448                         break;
 449                 case UCI_CMD_ADD:
 450                         prefix = "+";
 451                         break;
 452                 case UCI_CMD_REORDER:
 453                         prefix = "^";
 454                         break;
 455                 case UCI_CMD_LIST_ADD:
 456                         prefix = "|";
 457                         break;
 458                 default:
 459                         break;
 460                 }
 461
 462                 fprintf(f, "%s%s.%s", prefix, p->e.name, h->section);
 463                 if (e->name)
 464                         fprintf(f, ".%s", e->name);
 465
 466                 if (h->cmd == UCI_CMD_REMOVE)
 467                         fprintf(f, "\n");
 468                 else
 469                         fprintf(f, "=%s\n", h->value);
 470                 uci_free_history(h);
 471         }
 472
 473 done:
 474         uci_close_stream(f);
 475         if (filename)
 476                 free(filename);
 477         if (ctx->err)
 478                 UCI_THROW(ctx, ctx->err);
 479
 480         return 0;
 481 }
 482
 483