luci2/src/io/main.c

   1 /*
   2  * luci-io - LuCI non-RPC helper
   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 #define _GNU_SOURCE
  20 #define _XOPEN_SOURCE   700
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdbool.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <ctype.h>
  30 #include <sys/stat.h>
  31 #include <sys/wait.h>
  32
  33 #include <libubus.h>
  34 #include <libubox/blobmsg.h>
  35
  36 #ifdef HAVE_SHADOW
  37 #include <shadow.h>
  38 #endif
  39
  40 #include "login.h"
  41 #include "multipart_parser.h"
  42
  43
  44 enum part {
  45         PART_UNKNOWN,
  46         PART_SESSIONID,
  47         PART_FILENAME,
  48         PART_FILEMODE,
  49         PART_FILEDATA
  50 };
  51
  52 const char *parts[] = {
  53         "(bug)",
  54         "sessionid",
  55         "filename",
  56         "filemode",
  57         "filedata",
  58 };
  59
  60 struct state
  61 {
  62         bool is_content_disposition;
  63         enum part parttype;
  64         char *sessionid;
  65         char *filename;
  66         bool filedata;
  67         int filemode;
  68         int filefd;
  69         int tempfd;
  70 };
  71
  72 enum {
  73         SES_ACCESS,
  74         __SES_MAX,
  75 };
  76
  77 static const struct blobmsg_policy ses_policy[__SES_MAX] = {
  78         [SES_ACCESS] = { .name = "access", .type = BLOBMSG_TYPE_BOOL },
  79 };
  80
  81
  82 static struct state st;
  83
  84 static void
  85 session_access_cb(struct ubus_request *req, int type, struct blob_attr *msg)
  86 {
  87         struct blob_attr *tb[__SES_MAX];
  88         bool *allow = (bool *)req->priv;
  89
  90         if (!msg)
  91                 return;
  92
  93         blobmsg_parse(ses_policy, __SES_MAX, tb, blob_data(msg), blob_len(msg));
  94
  95         if (tb[SES_ACCESS])
  96                 *allow = blobmsg_get_bool(tb[SES_ACCESS]);
  97 }
  98
  99 static bool
 100 session_access(const char *sid, const char *obj, const char *func)
 101 {
 102         uint32_t id;
 103         bool allow = false;
 104         struct ubus_context *ctx;
 105         static struct blob_buf req;
 106
 107         ctx = ubus_connect(NULL);
 108
 109         if (!ctx || ubus_lookup_id(ctx, "session", &id))
 110                 goto out;
 111
 112         blob_buf_init(&req, 0);
 113         blobmsg_add_string(&req, "sid", sid);
 114         blobmsg_add_string(&req, "scope", "luci-io");
 115         blobmsg_add_string(&req, "object", obj);
 116         blobmsg_add_string(&req, "function", func);
 117
 118         ubus_invoke(ctx, id, "access", req.head, session_access_cb, &allow, 500);
 119
 120 out:
 121         if (ctx)
 122                 ubus_free(ctx);
 123
 124         return allow;
 125 }
 126
 127 static char *
 128 md5sum(const char *file)
 129 {
 130         pid_t pid;
 131         int fds[2];
 132         static char md5[33];
 133
 134         if (pipe(fds))
 135                 return NULL;
 136
 137         switch ((pid = fork()))
 138         {
 139         case -1:
 140                 return NULL;
 141
 142         case 0:
 143                 uloop_done();
 144
 145                 dup2(fds[1], 1);
 146
 147                 close(0);
 148                 close(2);
 149                 close(fds[0]);
 150                 close(fds[1]);
 151
 152                 if (execl("/bin/busybox", "/bin/busybox", "md5sum", file, NULL));
 153                         return NULL;
 154
 155                 break;
 156
 157         default:
 158                 memset(md5, 0, sizeof(md5));
 159                 read(fds[0], md5, 32);
 160                 waitpid(pid, NULL, 0);
 161                 close(fds[0]);
 162                 close(fds[1]);
 163         }
 164
 165         return md5;
 166 }
 167
 168 static char *
 169 datadup(const void *in, size_t len)
 170 {
 171         char *out = malloc(len + 1);
 172
 173         if (!out)
 174                 return NULL;
 175
 176         memcpy(out, in, len);
 177
 178         *(out + len) = 0;
 179
 180         return out;
 181 }
 182
 183 static bool
 184 urldecode(char *buf)
 185 {
 186         char *c, *p;
 187
 188         if (!buf || !*buf)
 189                 return true;
 190
 191 #define hex(x) \
 192         (((x) <= '9') ? ((x) - '0') : \
 193                 (((x) <= 'F') ? ((x) - 'A' + 10) : \
 194                         ((x) - 'a' + 10)))
 195
 196         for (c = p = buf; *p; c++)
 197         {
 198                 if (*p == '%')
 199                 {
 200                         if (!isxdigit(*(p + 1)) || !isxdigit(*(p + 2)))
 201                                 return false;
 202
 203                         *c = (char)(16 * hex(*(p + 1)) + hex(*(p + 2)));
 204
 205                         p += 3;
 206                 }
 207                 else if (*p == '+')
 208                 {
 209                         *c = ' ';
 210                         p++;
 211                 }
 212                 else
 213                 {
 214                         *c = *p++;
 215                 }
 216         }
 217
 218         *c = 0;
 219
 220         return true;
 221 }
 222
 223 static bool
 224 postdecode(char **fields, int n_fields)
 225 {
 226         char *p;
 227         const char *var;
 228         static char buf[1024];
 229         int i, len, field, found = 0;
 230
 231         var = getenv("CONTENT_TYPE");
 232
 233         if (!var || strncmp(var, "application/x-www-form-urlencoded", 33))
 234                 return false;
 235
 236         memset(buf, 0, sizeof(buf));
 237
 238         if ((len = read(0, buf, sizeof(buf) - 1)) > 0)
 239         {
 240                 for (p = buf, i = 0; i <= len; i++)
 241                 {
 242                         if (buf[i] == '=')
 243                         {
 244                                 buf[i] = 0;
 245
 246                                 for (field = 0; field < (n_fields * 2); field += 2)
 247                                 {
 248                                         if (!strcmp(p, fields[field]))
 249                                         {
 250                                                 fields[field + 1] = buf + i + 1;
 251                                                 found++;
 252                                         }
 253                                 }
 254                         }
 255                         else if (buf[i] == '&' || buf[i] == '\0')
 256                         {
 257                                 buf[i] = 0;
 258
 259                                 if (found >= n_fields)
 260                                         break;
 261
 262                                 p = buf + i + 1;
 263                         }
 264                 }
 265         }
 266
 267         for (field = 0; field < (n_fields * 2); field += 2)
 268                 if (!urldecode(fields[field + 1]))
 269                         return false;
 270
 271         return (found >= n_fields);
 272 }
 273
 274 static int
 275 response(bool success, const char *message)
 276 {
 277         char *md5;
 278         struct stat s;
 279
 280         printf("Status: 200 OK\r\n");
 281         printf("Content-Type: application/json\r\n\r\n{\n");
 282
 283         if (success)
 284         {
 285                 if (!stat(st.filename, &s) && (md5 = md5sum(st.filename)) != NULL)
 286                         printf("\t\"size\": %u,\n\t\"checksum\": \"%s\"\n",
 287                                    (unsigned int)s.st_size, md5);
 288         }
 289         else
 290         {
 291                 if (message)
 292                         printf("\t\"message\": \"%s\",\n", message);
 293
 294                 printf("\t\"failure\": [ %u, \"%s\" ]\n", errno, strerror(errno));
 295
 296                 if (st.filefd > -1)
 297                         unlink(st.filename);
 298         }
 299
 300         printf("}\n");
 301
 302         return -1;
 303 }
 304
 305 static int
 306 failure(int e, const char *message)
 307 {
 308         printf("Status: 500 Internal Server failure\r\n");
 309         printf("Content-Type: text/plain\r\n\r\n");
 310         printf(message);
 311
 312         if (e)
 313                 printf(": %s", strerror(e));
 314
 315         return -1;
 316 }
 317
 318 static int
 319 filecopy(void)
 320 {
 321         int len;
 322         char buf[4096];
 323
 324         if (!st.filedata)
 325         {
 326                 close(st.tempfd);
 327                 errno = EINVAL;
 328                 return response(false, "No file data received");
 329         }
 330
 331         if (lseek(st.tempfd, 0, SEEK_SET) < 0)
 332         {
 333                 close(st.tempfd);
 334                 return response(false, "Failed to rewind temp file");
 335         }
 336
 337         st.filefd = open(st.filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
 338
 339         if (st.filefd < 0)
 340         {
 341                 close(st.tempfd);
 342                 return response(false, "Failed to open target file");
 343         }
 344
 345         while ((len = read(st.tempfd, buf, sizeof(buf))) > 0)
 346         {
 347                 if (write(st.filefd, buf, len) != len)
 348                 {
 349                         close(st.tempfd);
 350                         close(st.filefd);
 351                         return response(false, "I/O failure while writing target file");
 352                 }
 353         }
 354
 355         close(st.tempfd);
 356         close(st.filefd);
 357
 358         if (chmod(st.filename, st.filemode))
 359                 return response(false, "Failed to chmod target file");
 360
 361         return 0;
 362 }
 363
 364 static int
 365 header_field(multipart_parser *p, const char *data, size_t len)
 366 {
 367         st.is_content_disposition = !strncasecmp(data, "Content-Disposition", len);
 368         return 0;
 369 }
 370
 371 static int
 372 header_value(multipart_parser *p, const char *data, size_t len)
 373 {
 374         int i, j;
 375
 376         if (!st.is_content_disposition)
 377                 return 0;
 378
 379         if (len < 10 || strncasecmp(data, "form-data", 9))
 380                 return 0;
 381
 382         for (data += 9, len -= 9; *data == ' ' || *data == ';'; data++, len--);
 383
 384         if (len < 8 || strncasecmp(data, "name=\"", 6))
 385                 return 0;
 386
 387         for (data += 6, len -= 6, i = 0; i <= len; i++)
 388         {
 389                 if (*(data + i) != '"')
 390                         continue;
 391
 392                 for (j = 1; j < sizeof(parts) / sizeof(parts[0]); j++)
 393                         if (!strncmp(data, parts[j], i))
 394                                 st.parttype = j;
 395
 396                 break;
 397         }
 398
 399         return 0;
 400 }
 401
 402 static int
 403 data_begin_cb(multipart_parser *p)
 404 {
 405         char tmpname[24] = "/tmp/luci-upload.XXXXXX";
 406
 407         if (st.parttype == PART_FILEDATA)
 408         {
 409                 if (!st.sessionid)
 410                         return response(false, "File data without session");
 411
 412                 if (!st.filename)
 413                         return response(false, "File data without name");
 414
 415                 st.tempfd = mkstemp(tmpname);
 416
 417                 if (st.tempfd < 0)
 418                         return response(false, "Failed to create temporary file");
 419
 420                 unlink(tmpname);
 421         }
 422
 423         return 0;
 424 }
 425
 426 static int
 427 data_cb(multipart_parser *p, const char *data, size_t len)
 428 {
 429         switch (st.parttype)
 430         {
 431         case PART_SESSIONID:
 432                 st.sessionid = datadup(data, len);
 433                 break;
 434
 435         case PART_FILENAME:
 436                 st.filename = datadup(data, len);
 437                 break;
 438
 439         case PART_FILEMODE:
 440                 st.filemode = strtoul(data, NULL, 8);
 441                 break;
 442
 443         case PART_FILEDATA:
 444                 if (write(st.tempfd, data, len) != len)
 445                 {
 446                         close(st.tempfd);
 447                         return response(false, "I/O failure while writing temporary file");
 448                 }
 449
 450                 if (!st.filedata)
 451                         st.filedata = !!len;
 452
 453                 break;
 454
 455         default:
 456                 break;
 457         }
 458
 459         return 0;
 460 }
 461
 462 static int
 463 data_end_cb(multipart_parser *p)
 464 {
 465         if (st.parttype == PART_SESSIONID)
 466         {
 467                 if (!session_access(st.sessionid, "upload", "write"))
 468                 {
 469                         errno = EPERM;
 470                         return response(false, "Upload permission denied");
 471                 }
 472         }
 473         else if (st.parttype == PART_FILEDATA)
 474         {
 475                 if (st.tempfd < 0)
 476                         return response(false, "Internal program failure");
 477
 478 #if 0
 479                 /* prepare directory */
 480                 for (ptr = st.filename; *ptr; ptr++)
 481                 {
 482                         if (*ptr == '/')
 483                         {
 484                                 *ptr = 0;
 485
 486                                 if (mkdir(st.filename, 0755))
 487                                 {
 488                                         unlink(st.tmpname);
 489                                         return response(false, "Failed to create destination directory");
 490                                 }
 491
 492                                 *ptr = '/';
 493                         }
 494                 }
 495 #endif
 496
 497                 if (filecopy())
 498                         return -1;
 499
 500                 return response(true, NULL);
 501         }
 502
 503         st.parttype = PART_UNKNOWN;
 504         return 0;
 505 }
 506
 507 static multipart_parser *
 508 init_parser(void)
 509 {
 510         char *boundary;
 511         const char *var;
 512
 513         multipart_parser *p;
 514         multipart_parser_settings s = {
 515                 .on_part_data        = data_cb,
 516                 .on_headers_complete = data_begin_cb,
 517                 .on_part_data_end    = data_end_cb,
 518                 .on_header_field     = header_field,
 519                 .on_header_value     = header_value
 520         };
 521
 522         var = getenv("CONTENT_TYPE");
 523
 524         if (!var || strncmp(var, "multipart/form-data;", 20))
 525                 return NULL;
 526
 527         for (var += 20; *var && *var != '='; var++);
 528
 529         if (*var++ != '=')
 530                 return NULL;
 531
 532         boundary = malloc(strlen(var) + 3);
 533
 534         if (!boundary)
 535                 return NULL;
 536
 537         strcpy(boundary, "--");
 538         strcpy(boundary + 2, var);
 539
 540         st.tempfd = -1;
 541         st.filefd = -1;
 542         st.filemode = 0600;
 543
 544         p = multipart_parser_init(boundary, &s);
 545
 546         free(boundary);
 547
 548         return p;
 549 }
 550
 551 static int
 552 main_upload(int argc, char *argv[])
 553 {
 554         int rem, len;
 555         char buf[4096];
 556         multipart_parser *p;
 557
 558         p = init_parser();
 559
 560         if (!p)
 561         {
 562                 errno = EINVAL;
 563                 return response(false, "Invalid request");
 564         }
 565
 566         while ((len = read(0, buf, sizeof(buf))) > 0)
 567         {
 568                 rem = multipart_parser_execute(p, buf, len);
 569
 570                 if (rem < len)
 571                         break;
 572         }
 573
 574         multipart_parser_free(p);
 575
 576         /* read remaining post data */
 577         while ((len = read(0, buf, sizeof(buf))) > 0);
 578
 579         return 0;
 580 }
 581
 582 static int
 583 main_backup(int argc, char **argv)
 584 {
 585         pid_t pid;
 586         time_t now;
 587         int len;
 588         int fds[2];
 589         char buf[4096];
 590         char datestr[16] = { 0 };
 591         char hostname[64] = { 0 };
 592         char *fields[] = { "sessionid", NULL };
 593
 594         if (!postdecode(fields, 1) || !session_access(fields[1], "backup", "read"))
 595                 return failure(0, "Backup permission denied");
 596
 597         if (pipe(fds))
 598                 return failure(errno, "Failed to spawn pipe");
 599
 600         switch ((pid = fork()))
 601         {
 602         case -1:
 603                 return failure(errno, "Failed to fork process");
 604
 605         case 0:
 606                 dup2(fds[1], 1);
 607
 608                 close(0);
 609                 close(2);
 610                 close(fds[0]);
 611                 close(fds[1]);
 612
 613                 chdir("/");
 614
 615                 execl("/sbin/sysupgrade", "/sbin/sysupgrade",
 616                       "--create-backup", "-", NULL);
 617
 618                 return -1;
 619
 620         default:
 621                 now = time(NULL);
 622                 strftime(datestr, sizeof(datestr) - 1, "%Y-%m-%d", localtime(&now));
 623
 624                 if (gethostname(hostname, sizeof(hostname) - 1))
 625                         sprintf(hostname, "OpenWrt");
 626
 627                 printf("Status: 200 OK\r\n");
 628                 printf("Content-Type: application/x-targz\r\n");
 629                 printf("Content-Disposition: attachment; "
 630                        "filename=\"backup-%s-%s.tar.gz\"\r\n\r\n", hostname, datestr);
 631
 632                 while ((len = read(fds[0], buf, sizeof(buf))) > 0)
 633                         fwrite(buf, len, 1, stdout);
 634
 635                 waitpid(pid, NULL, 0);
 636
 637                 close(fds[0]);
 638                 close(fds[1]);
 639
 640                 return 0;
 641         }
 642 }
 643
 644 static int
 645 main_login(int argc, char **argv)
 646 {
 647         char *hash, *fields[] = { "username", NULL, "password", NULL };
 648         const char *sid = NULL;
 649
 650         if (postdecode(fields, 2))
 651         {
 652 #ifdef HAVE_SHADOW
 653                 struct spwd *sp = getspnam(fields[1]);
 654
 655                 if (!sp)
 656                         goto inval;
 657
 658                 /* check whether a password is set */
 659                 if (sp->sp_pwdp && *sp->sp_pwdp &&
 660                     strcmp(sp->sp_pwdp, "!") && strcmp(sp->sp_pwdp, "x"))
 661                 {
 662                         hash = crypt(fields[3], sp->sp_pwdp);
 663
 664                         if (strcmp(hash, sp->sp_pwdp))
 665                                 goto inval;
 666                 }
 667 #else
 668                 struct passwd *pw = getpwnam(fields[1]);
 669
 670                 if (!pw)
 671                         goto inval;
 672
 673                 /* check whether a password is set */
 674                 if (pw->pw_passwd && *pw->pw_passwd &&
 675                     strcmp(pw->pw_passwd, "!") && strcmp(pw->pw_passwd, "x"))
 676                 {
 677                         hash = crypt(fields[3], pw->pw_passwd);
 678
 679                         if (strcmp(hash, pw->pw_passwd))
 680                                 goto inval;
 681                 }
 682 #endif
 683
 684                 sid = setup_session(fields[1]);
 685
 686                 if (!sid)
 687                         goto inval;
 688
 689                 printf("Status: 200 OK\r\n");
 690                 printf("Content-Type: application/json\r\n\r\n{\n");
 691                 printf("\t\"sessionid\": \"%s\"\n}\n", sid);
 692                 return 0;
 693         }
 694
 695 inval:
 696         printf("Status: 200 OK\r\n");
 697         printf("Content-Type: application/json\r\n\r\n{}\n");
 698         return 1;
 699 }
 700
 701 int main(int argc, char **argv)
 702 {
 703         if (strstr(argv[0], "luci-upload"))
 704                 return main_upload(argc, argv);
 705         else if (strstr(argv[0], "luci-backup"))
 706                 return main_backup(argc, argv);
 707         else if (strstr(argv[0], "luci-login"))
 708                 return main_login(argc, argv);
 709
 710         return -1;
 711 }