file.c

   1 /*
   2  * luci-rpcd - LuCI UBUS RPC server
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <fcntl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <limits.h>
  25 #include <dirent.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28
  29 #include "file.h"
  30
  31 static struct blob_buf buf;
  32
  33 enum {
  34         RPC_F_PATH,
  35         RPC_F_DATA,
  36         __RPC_F_MAX,
  37 };
  38
  39 static const struct blobmsg_policy rpc_file_policy[__RPC_F_MAX] = {
  40         [RPC_F_PATH] = { .name = "path", .type = BLOBMSG_TYPE_STRING },
  41         [RPC_F_DATA] = { .name = "data", .type = BLOBMSG_TYPE_STRING },
  42 };
  43
  44 enum {
  45         RPC_E_CMD,
  46         RPC_E_PARM,
  47         RPC_E_ENV,
  48         __RPC_E_MAX,
  49 };
  50
  51 static const struct blobmsg_policy rpc_exec_policy[__RPC_E_MAX] = {
  52         [RPC_E_CMD] = { .name = "command", .type = BLOBMSG_TYPE_STRING },
  53         [RPC_E_PARM] = { .name = "params",  .type = BLOBMSG_TYPE_ARRAY  },
  54         [RPC_E_ENV]  = { .name = "env",     .type = BLOBMSG_TYPE_TABLE  },
  55 };
  56
  57 static const char *d_types[] = {
  58         [DT_BLK]     = "block",
  59         [DT_CHR]     = "char",
  60         [DT_DIR]     = "directory",
  61         [DT_FIFO]    = "fifo",
  62         [DT_LNK]     = "symlink",
  63         [DT_REG]     = "file",
  64         [DT_SOCK]    = "socket",
  65         [DT_UNKNOWN] = "unknown",
  66 };
  67
  68
  69 static int
  70 rpc_errno_status(void)
  71 {
  72         switch (errno)
  73         {
  74         case EACCES:
  75                 return UBUS_STATUS_PERMISSION_DENIED;
  76
  77         case ENOTDIR:
  78                 return UBUS_STATUS_INVALID_ARGUMENT;
  79
  80         case ENOENT:
  81                 return UBUS_STATUS_NOT_FOUND;
  82
  83         case EINVAL:
  84                 return UBUS_STATUS_INVALID_ARGUMENT;
  85
  86         default:
  87                 return UBUS_STATUS_UNKNOWN_ERROR;
  88         }
  89 }
  90
  91 static struct blob_attr **
  92 rpc_check_path(struct blob_attr *msg, char **path, struct stat *s)
  93 {
  94         static struct blob_attr *tb[__RPC_F_MAX];
  95
  96         blobmsg_parse(rpc_file_policy, __RPC_F_MAX, tb, blob_data(msg), blob_len(msg));
  97
  98         if (!tb[RPC_F_PATH])
  99         {
 100                 errno = EINVAL;
 101                 return NULL;
 102         }
 103
 104         *path = blobmsg_data(tb[RPC_F_PATH]);
 105
 106         if (stat(*path, s))
 107                 return NULL;
 108
 109         return tb;
 110 }
 111
 112 static int
 113 rpc_file_read(struct ubus_context *ctx, struct ubus_object *obj,
 114               struct ubus_request_data *req, const char *method,
 115               struct blob_attr *msg)
 116 {
 117         int fd, rv, len;
 118         char *path;
 119         struct stat s;
 120         char *wbuf;
 121
 122         if (!rpc_check_path(msg, &path, &s))
 123                 return rpc_errno_status();
 124
 125         if (s.st_size >= RPC_FILE_MAX_SIZE)
 126                 return UBUS_STATUS_NOT_SUPPORTED;
 127
 128         if ((fd = open(path, O_RDONLY)) < 0)
 129                 return rpc_errno_status();
 130
 131         /* some sysfs files do not report a length */
 132         if (s.st_size == 0)
 133                 s.st_size = RPC_FILE_MIN_SIZE;
 134
 135         blob_buf_init(&buf, 0);
 136
 137         wbuf = blobmsg_alloc_string_buffer(&buf, "data", s.st_size + 1);
 138
 139         if (!wbuf)
 140         {
 141                 rv = UBUS_STATUS_UNKNOWN_ERROR;
 142                 goto out;
 143         }
 144
 145         if ((len = read(fd, wbuf, s.st_size)) <= 0)
 146         {
 147                 rv = UBUS_STATUS_NO_DATA;
 148                 goto out;
 149         }
 150
 151         *(wbuf + len) = 0;
 152         blobmsg_add_string_buffer(&buf);
 153
 154         ubus_send_reply(ctx, req, buf.head);
 155         rv = UBUS_STATUS_OK;
 156
 157 out:
 158         close(fd);
 159         return rv;
 160 }
 161
 162 static int
 163 rpc_file_write(struct ubus_context *ctx, struct ubus_object *obj,
 164                struct ubus_request_data *req, const char *method,
 165                struct blob_attr *msg)
 166 {
 167         int fd;
 168         char *path;
 169         struct stat s;
 170         struct blob_attr **tb;
 171
 172         if (!(tb = rpc_check_path(msg, &path, &s)))
 173                 return rpc_errno_status();
 174
 175         if (!tb[RPC_F_DATA])
 176                 return UBUS_STATUS_INVALID_ARGUMENT;
 177
 178         if ((fd = open(path, O_WRONLY)) < 0)
 179                 return rpc_errno_status();
 180
 181         write(fd, blobmsg_data(tb[RPC_F_DATA]), blobmsg_data_len(tb[RPC_F_DATA]));
 182         close(fd);
 183
 184         return 0;
 185 }
 186
 187 static int
 188 rpc_file_list(struct ubus_context *ctx, struct ubus_object *obj,
 189               struct ubus_request_data *req, const char *method,
 190               struct blob_attr *msg)
 191 {
 192         DIR *fd;
 193         void *c, *d;
 194         char *path;
 195         struct stat s;
 196         struct dirent *e;
 197
 198         if (!rpc_check_path(msg, &path, &s))
 199                 return rpc_errno_status();
 200
 201         if ((fd = opendir(path)) == NULL)
 202                 return rpc_errno_status();
 203
 204         blob_buf_init(&buf, 0);
 205         c = blobmsg_open_array(&buf, "entries");
 206
 207         while ((e = readdir(fd)) != NULL)
 208         {
 209                 if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, ".."))
 210                         continue;
 211
 212                 d = blobmsg_open_table(&buf, NULL);
 213                 blobmsg_add_string(&buf, "name", e->d_name);
 214                 blobmsg_add_string(&buf, "type", d_types[e->d_type]);
 215                 blobmsg_close_table(&buf, d);
 216         }
 217
 218         blobmsg_close_array(&buf, c);
 219         ubus_send_reply(ctx, req, buf.head);
 220
 221         return 0;
 222 }
 223
 224 static int
 225 rpc_file_stat(struct ubus_context *ctx, struct ubus_object *obj,
 226               struct ubus_request_data *req, const char *method,
 227               struct blob_attr *msg)
 228 {
 229         int type;
 230         char *path;
 231         struct stat s;
 232
 233         if (!rpc_check_path(msg, &path, &s))
 234                 return rpc_errno_status();
 235
 236         blob_buf_init(&buf, 0);
 237
 238         type = S_ISREG(s.st_mode) ? DT_REG :
 239                 S_ISDIR(s.st_mode) ? DT_DIR :
 240                  S_ISCHR(s.st_mode) ? DT_CHR :
 241                   S_ISBLK(s.st_mode) ? DT_BLK :
 242                    S_ISFIFO(s.st_mode) ? DT_FIFO :
 243                     S_ISLNK(s.st_mode) ? DT_LNK :
 244                      S_ISSOCK(s.st_mode) ? DT_SOCK :
 245                       DT_UNKNOWN;
 246
 247         blobmsg_add_string(&buf, "path", path);
 248         blobmsg_add_string(&buf, "type", d_types[type]);
 249         blobmsg_add_u32(&buf, "size",  s.st_size);
 250         blobmsg_add_u32(&buf, "mode",  s.st_mode);
 251         blobmsg_add_u32(&buf, "atime", s.st_atime);
 252         blobmsg_add_u32(&buf, "mtime", s.st_mtime);
 253         blobmsg_add_u32(&buf, "ctime", s.st_ctime);
 254         blobmsg_add_u32(&buf, "inode", s.st_ino);
 255         blobmsg_add_u32(&buf, "uid",   s.st_uid);
 256         blobmsg_add_u32(&buf, "gid",   s.st_gid);
 257
 258         ubus_send_reply(ctx, req, buf.head);
 259
 260         return 0;
 261 }
 262
 263 static const char *
 264 rpc_file_exec_lookup(const char *cmd)
 265 {
 266         struct stat s;
 267         int plen = 0, clen = strlen(cmd) + 1;
 268         char *search, *p;
 269         static char path[PATH_MAX];
 270
 271         if (!stat(cmd, &s) && S_ISREG(s.st_mode))
 272                 return cmd;
 273
 274         search = getenv("PATH");
 275
 276         if (!search)
 277                 search = "/bin:/usr/bin:/sbin:/usr/sbin";
 278
 279         p = search;
 280
 281         do
 282         {
 283                 if (*p != ':' && *p != '\0')
 284                         continue;
 285
 286                 plen = p - search;
 287
 288                 if ((plen + clen) >= sizeof(path))
 289                         continue;
 290
 291                 strncpy(path, search, plen);
 292                 sprintf(path + plen, "/%s", cmd);
 293
 294                 if (!stat(path, &s) && S_ISREG(s.st_mode))
 295                         return path;
 296
 297                 search = p + 1;
 298         }
 299         while (*p++);
 300
 301         return NULL;
 302 }
 303
 304
 305 static void
 306 rpc_ustream_to_blobmsg(struct ustream *s, const char *name)
 307 {
 308         int len;
 309         char *rbuf, *wbuf;
 310
 311         if ((len = ustream_pending_data(s, false)) > 0)
 312         {
 313                 wbuf = blobmsg_alloc_string_buffer(&buf, name, len + 1);
 314
 315                 if (!wbuf)
 316                         return;
 317
 318                 ustream_for_each_read_buffer(s, rbuf, len)
 319                 {
 320                         memcpy(wbuf, rbuf, len);
 321                         wbuf += len;
 322                 }
 323
 324                 *wbuf = 0;
 325                 blobmsg_add_string_buffer(&buf);
 326         }
 327 }
 328
 329 static void
 330 rpc_file_exec_reply(struct rpc_file_exec_context *c, int rv)
 331 {
 332         uloop_timeout_cancel(&c->timeout);
 333         uloop_process_delete(&c->process);
 334
 335         if (rv == UBUS_STATUS_OK)
 336         {
 337                 blob_buf_init(&buf, 0);
 338
 339                 blobmsg_add_u32(&buf, "code", WEXITSTATUS(c->stat));
 340
 341                 rpc_ustream_to_blobmsg(&c->opipe.stream, "stdout");
 342                 rpc_ustream_to_blobmsg(&c->epipe.stream, "stderr");
 343
 344                 ubus_send_reply(c->context, &c->request, buf.head);
 345         }
 346
 347         ubus_complete_deferred_request(c->context, &c->request, rv);
 348
 349         ustream_free(&c->opipe.stream);
 350         ustream_free(&c->epipe.stream);
 351
 352         close(c->opipe.fd.fd);
 353         close(c->epipe.fd.fd);
 354
 355         free(c);
 356 }
 357
 358 static void
 359 rpc_file_exec_timeout_cb(struct uloop_timeout *t)
 360 {
 361         struct rpc_file_exec_context *c =
 362                 container_of(t, struct rpc_file_exec_context, timeout);
 363
 364         kill(c->process.pid, SIGKILL);
 365         rpc_file_exec_reply(c, UBUS_STATUS_TIMEOUT);
 366 }
 367
 368 static void
 369 rpc_file_exec_process_cb(struct uloop_process *p, int stat)
 370 {
 371         struct rpc_file_exec_context *c =
 372                 container_of(p, struct rpc_file_exec_context, process);
 373
 374         c->stat = stat;
 375
 376         ustream_poll(&c->opipe.stream);
 377         ustream_poll(&c->epipe.stream);
 378 }
 379
 380 static void
 381 rpc_file_exec_opipe_read_cb(struct ustream *s, int bytes)
 382 {
 383         struct rpc_file_exec_context *c =
 384                 container_of(s, struct rpc_file_exec_context, opipe.stream);
 385
 386         if (ustream_read_buf_full(s))
 387                 rpc_file_exec_reply(c, UBUS_STATUS_NOT_SUPPORTED);
 388 }
 389
 390 static void
 391 rpc_file_exec_epipe_read_cb(struct ustream *s, int bytes)
 392 {
 393         struct rpc_file_exec_context *c =
 394                 container_of(s, struct rpc_file_exec_context, epipe.stream);
 395
 396         if (ustream_read_buf_full(s))
 397                 rpc_file_exec_reply(c, UBUS_STATUS_NOT_SUPPORTED);
 398 }
 399
 400 static void
 401 rpc_file_exec_opipe_state_cb(struct ustream *s)
 402 {
 403         struct rpc_file_exec_context *c =
 404                 container_of(s, struct rpc_file_exec_context, opipe.stream);
 405
 406         if (c->opipe.stream.eof && c->epipe.stream.eof)
 407                 rpc_file_exec_reply(c, UBUS_STATUS_OK);
 408 }
 409
 410 static void
 411 rpc_file_exec_epipe_state_cb(struct ustream *s)
 412 {
 413         struct rpc_file_exec_context *c =
 414                 container_of(s, struct rpc_file_exec_context, epipe.stream);
 415
 416         if (c->opipe.stream.eof && c->epipe.stream.eof)
 417                 rpc_file_exec_reply(c, UBUS_STATUS_OK);
 418 }
 419
 420 static int
 421 rpc_file_exec_run(const char *cmd,
 422                               const struct blob_attr *arg, const struct blob_attr *env,
 423                   struct ubus_context *ctx, struct ubus_request_data *req)
 424 {
 425         pid_t pid;
 426
 427         int opipe[2];
 428         int epipe[2];
 429
 430         int rem;
 431         struct blob_attr *cur;
 432
 433         char arglen;
 434         char **args;
 435
 436         struct rpc_file_exec_context *c;
 437
 438         cmd = rpc_file_exec_lookup(cmd);
 439
 440         if (!cmd)
 441                 return UBUS_STATUS_NOT_FOUND;
 442
 443         c = malloc(sizeof(*c));
 444
 445         if (!c)
 446                 return UBUS_STATUS_UNKNOWN_ERROR;
 447
 448         if (pipe(opipe) || pipe(epipe))
 449                 return rpc_errno_status();
 450
 451         switch ((pid = fork()))
 452         {
 453         case -1:
 454                 return rpc_errno_status();
 455
 456         case 0:
 457                 uloop_done();
 458
 459                 dup2(opipe[1], 1);
 460                 dup2(epipe[1], 2);
 461
 462                 close(0);
 463                 close(opipe[0]);
 464                 close(opipe[1]);
 465                 close(epipe[0]);
 466                 close(epipe[1]);
 467
 468                 arglen = 2;
 469                 args = malloc(sizeof(char *) * arglen);
 470
 471                 if (!args)
 472                         return UBUS_STATUS_UNKNOWN_ERROR;
 473
 474                 args[0] = (char *)cmd;
 475                 args[1] = NULL;
 476
 477                 if (arg)
 478                 {
 479                         blobmsg_for_each_attr(cur, arg, rem)
 480                         {
 481                                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 482                                         continue;
 483
 484                                 arglen++;
 485
 486                                 if (!(args = realloc(args, sizeof(char *) * arglen)))
 487                                         return UBUS_STATUS_UNKNOWN_ERROR;
 488
 489                                 args[arglen-2] = blobmsg_data(cur);
 490                                 args[arglen-1] = NULL;
 491                         }
 492                 }
 493
 494                 if (env)
 495                 {
 496                         blobmsg_for_each_attr(cur, env, rem)
 497                         {
 498                                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 499                                         continue;
 500
 501                                 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 502                         }
 503                 }
 504
 505                 if (execv(cmd, args))
 506                         return rpc_errno_status();
 507
 508         default:
 509                 memset(c, 0, sizeof(*c));
 510
 511                 ustream_declare(c->opipe, opipe[0], exec_opipe);
 512                 ustream_declare(c->epipe, epipe[0], exec_epipe);
 513
 514                 c->process.pid = pid;
 515                 c->process.cb = rpc_file_exec_process_cb;
 516                 uloop_process_add(&c->process);
 517
 518                 c->timeout.cb = rpc_file_exec_timeout_cb;
 519                 uloop_timeout_set(&c->timeout, RPC_FILE_MAX_RUNTIME);
 520
 521                 close(opipe[1]);
 522                 close(epipe[1]);
 523
 524                 c->context = ctx;
 525                 ubus_defer_request(ctx, req, &c->request);
 526         }
 527
 528         return UBUS_STATUS_OK;
 529 }
 530
 531 static int
 532 rpc_file_exec(struct ubus_context *ctx, struct ubus_object *obj,
 533               struct ubus_request_data *req, const char *method,
 534               struct blob_attr *msg)
 535 {
 536         struct blob_attr *tb[__RPC_E_MAX];
 537
 538         blobmsg_parse(rpc_exec_policy, __RPC_E_MAX, tb,
 539                       blob_data(msg), blob_len(msg));
 540
 541         if (!tb[RPC_E_CMD])
 542                 return UBUS_STATUS_INVALID_ARGUMENT;
 543
 544         return rpc_file_exec_run(blobmsg_data(tb[RPC_E_CMD]),
 545                                                  tb[RPC_E_PARM], tb[RPC_E_ENV], ctx, req);
 546 }
 547
 548
 549 int rpc_file_api_init(struct ubus_context *ctx)
 550 {
 551         static const struct ubus_method file_methods[] = {
 552                 UBUS_METHOD("read",    rpc_file_read,  rpc_file_policy),
 553                 UBUS_METHOD("write",   rpc_file_write, rpc_file_policy),
 554                 UBUS_METHOD("list",    rpc_file_list,  rpc_file_policy),
 555                 UBUS_METHOD("stat",    rpc_file_stat,  rpc_file_policy),
 556                 UBUS_METHOD("exec",    rpc_file_exec,  rpc_exec_policy),
 557         };
 558
 559         static struct ubus_object_type file_type =
 560                 UBUS_OBJECT_TYPE("luci-rpc-file", file_methods);
 561
 562         static struct ubus_object obj = {
 563                 .name = "file",
 564                 .type = &file_type,
 565                 .methods = file_methods,
 566                 .n_methods = ARRAY_SIZE(file_methods),
 567         };
 568
 569         return ubus_add_object(ctx, &obj);
 570 }