file.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #define _BSD_SOURCE
  21 #define _DARWIN_C_SOURCE
  22 #define _XOPEN_SOURCE 700
  23
  24 #include <sys/types.h>
  25 #include <sys/dir.h>
  26 #include <time.h>
  27 #include <strings.h>
  28 #include <dirent.h>
  29 #include <inttypes.h>
  30
  31 #include <libubox/blobmsg.h>
  32
  33 #include "uhttpd.h"
  34 #include "mimetypes.h"
  35
  36 #define MAX(a, b)       (((a) > (b)) ? (a) : (b))
  37
  38 static LIST_HEAD(index_files);
  39 static LIST_HEAD(dispatch_handlers);
  40 static LIST_HEAD(pending_requests);
  41 static int n_requests;
  42
  43 struct deferred_request {
  44         struct list_head list;
  45         struct dispatch_handler *d;
  46         struct client *cl;
  47         struct path_info pi;
  48         bool called, path;
  49 };
  50
  51 struct index_file {
  52         struct list_head list;
  53         const char *name;
  54 };
  55
  56 enum file_hdr {
  57         HDR_AUTHORIZATION,
  58         HDR_IF_MODIFIED_SINCE,
  59         HDR_IF_UNMODIFIED_SINCE,
  60         HDR_IF_MATCH,
  61         HDR_IF_NONE_MATCH,
  62         HDR_IF_RANGE,
  63         __HDR_MAX
  64 };
  65
  66 void uh_index_add(const char *filename)
  67 {
  68         struct index_file *idx;
  69
  70         idx = calloc(1, sizeof(*idx));
  71         idx->name = filename;
  72         list_add_tail(&idx->list, &index_files);
  73 }
  74
  75 static char * canonpath(const char *path, char *path_resolved)
  76 {
  77         const char *path_cpy = path;
  78         char *path_res = path_resolved;
  79
  80         if (conf.no_symlinks)
  81                 return realpath(path, path_resolved);
  82
  83         /* normalize */
  84         while ((*path_cpy != '\0') && (path_cpy < (path + PATH_MAX - 2))) {
  85                 if (*path_cpy != '/')
  86                         goto next;
  87
  88                 /* skip repeating / */
  89                 if (path_cpy[1] == '/') {
  90                         path_cpy++;
  91                         continue;
  92                 }
  93
  94                 /* /./ or /../ */
  95                 if (path_cpy[1] == '.') {
  96                         /* skip /./ */
  97                         if ((path_cpy[2] == '/') || (path_cpy[2] == '\0')) {
  98                                 path_cpy += 2;
  99                                 continue;
 100                         }
 101
 102                         /* collapse /x/../ */
 103                         if ((path_cpy[2] == '.') &&
 104                             ((path_cpy[3] == '/') || (path_cpy[3] == '\0'))) {
 105                                 while ((path_res > path_resolved) && (*--path_res != '/'));
 106
 107                                 path_cpy += 3;
 108                                 continue;
 109                         }
 110                 }
 111
 112 next:
 113                 *path_res++ = *path_cpy++;
 114         }
 115
 116         /* remove trailing slash if not root / */
 117         if ((path_res > (path_resolved+1)) && (path_res[-1] == '/'))
 118                 path_res--;
 119         else if (path_res == path_resolved)
 120                 *path_res++ = '/';
 121
 122         *path_res = '\0';
 123
 124         return path_resolved;
 125 }
 126
 127 /* Returns NULL on error.
 128 ** NB: improperly encoded URL should give client 400 [Bad Syntax]; returning
 129 ** NULL here causes 404 [Not Found], but that's not too unreasonable. */
 130 struct path_info *
 131 uh_path_lookup(struct client *cl, const char *url)
 132 {
 133         static char path_phys[PATH_MAX];
 134         static char path_info[PATH_MAX];
 135         static struct path_info p;
 136
 137         const char *docroot = conf.docroot;
 138         int docroot_len = strlen(docroot);
 139         char *pathptr = NULL;
 140         bool slash;
 141
 142         int i = 0;
 143         int len;
 144         struct stat s;
 145         struct index_file *idx;
 146
 147         /* back out early if url is undefined */
 148         if (url == NULL)
 149                 return NULL;
 150
 151         memset(&p, 0, sizeof(p));
 152         path_phys[0] = 0;
 153         path_info[0] = 0;
 154
 155         strcpy(uh_buf, docroot);
 156
 157         /* separate query string from url */
 158         if ((pathptr = strchr(url, '?')) != NULL) {
 159                 p.query = pathptr[1] ? pathptr + 1 : NULL;
 160
 161                 /* urldecode component w/o query */
 162                 if (pathptr > url) {
 163                         if (uh_urldecode(&uh_buf[docroot_len],
 164                                          sizeof(uh_buf) - docroot_len - 1,
 165                                          url, pathptr - url ) < 0)
 166                                 return NULL;
 167                 }
 168         }
 169
 170         /* no query string, decode all of url */
 171         else if (uh_urldecode(&uh_buf[docroot_len],
 172                               sizeof(uh_buf) - docroot_len - 1,
 173                               url, strlen(url) ) < 0)
 174                 return NULL;
 175
 176         /* create canon path */
 177         len = strlen(uh_buf);
 178         slash = len && uh_buf[len - 1] == '/';
 179         len = min(len, sizeof(path_phys) - 1);
 180
 181         for (i = len; i >= 0; i--) {
 182                 char ch = uh_buf[i];
 183                 bool exists;
 184
 185                 if (ch != 0 && ch != '/')
 186                         continue;
 187
 188                 uh_buf[i] = 0;
 189                 exists = !!canonpath(uh_buf, path_phys);
 190                 uh_buf[i] = ch;
 191
 192                 if (!exists)
 193                         continue;
 194
 195                 /* test current path */
 196                 if (stat(path_phys, &p.stat))
 197                         continue;
 198
 199                 snprintf(path_info, sizeof(path_info), "%s", uh_buf + i);
 200                 break;
 201         }
 202
 203         /* check whether found path is within docroot */
 204         if (strncmp(path_phys, docroot, docroot_len) != 0 ||
 205             (path_phys[docroot_len] != 0 &&
 206              path_phys[docroot_len] != '/'))
 207                 return NULL;
 208
 209         /* is a regular file */
 210         if (p.stat.st_mode & S_IFREG) {
 211                 p.root = docroot;
 212                 p.phys = path_phys;
 213                 p.name = &path_phys[docroot_len];
 214                 p.info = path_info[0] ? path_info : NULL;
 215                 return &p;
 216         }
 217
 218         if (!(p.stat.st_mode & S_IFDIR))
 219                 return NULL;
 220
 221         if (path_info[0])
 222             return NULL;
 223
 224         pathptr = path_phys + strlen(path_phys);
 225
 226         /* ensure trailing slash */
 227         if (pathptr[-1] != '/') {
 228                 pathptr[0] = '/';
 229                 pathptr[1] = 0;
 230                 pathptr++;
 231         }
 232
 233         /* if requested url resolves to a directory and a trailing slash
 234            is missing in the request url, redirect the client to the same
 235            url with trailing slash appended */
 236         if (!slash) {
 237                 uh_http_header(cl, 302, "Found");
 238                 ustream_printf(cl->us, "Content-Length: 0\r\n");
 239                 ustream_printf(cl->us, "Location: %s%s%s\r\n\r\n",
 240                                 &path_phys[docroot_len],
 241                                 p.query ? "?" : "",
 242                                 p.query ? p.query : "");
 243                 uh_request_done(cl);
 244                 p.redirected = 1;
 245                 return &p;
 246         }
 247
 248         /* try to locate index file */
 249         len = path_phys + sizeof(path_phys) - pathptr - 1;
 250         list_for_each_entry(idx, &index_files, list) {
 251                 if (strlen(idx->name) > len)
 252                         continue;
 253
 254                 strcpy(pathptr, idx->name);
 255                 if (!stat(path_phys, &s) && (s.st_mode & S_IFREG)) {
 256                         memcpy(&p.stat, &s, sizeof(p.stat));
 257                         break;
 258                 }
 259
 260                 *pathptr = 0;
 261         }
 262
 263         p.root = docroot;
 264         p.phys = path_phys;
 265         p.name = &path_phys[docroot_len];
 266
 267         return p.phys ? &p : NULL;
 268 }
 269
 270 static const char * uh_file_mime_lookup(const char *path)
 271 {
 272         const struct mimetype *m = &uh_mime_types[0];
 273         const char *e;
 274
 275         while (m->extn) {
 276                 e = &path[strlen(path)-1];
 277
 278                 while (e >= path) {
 279                         if ((*e == '.' || *e == '/') && !strcasecmp(&e[1], m->extn))
 280                                 return m->mime;
 281
 282                         e--;
 283                 }
 284
 285                 m++;
 286         }
 287
 288         return "application/octet-stream";
 289 }
 290
 291 static const char * uh_file_mktag(struct stat *s, char *buf, int len)
 292 {
 293         snprintf(buf, len, "\"%" PRIx64 "-%" PRIx64 "-%" PRIx64 "\"",
 294                  s->st_ino, s->st_size, (uint64_t)s->st_mtime);
 295
 296         return buf;
 297 }
 298
 299 static time_t uh_file_date2unix(const char *date)
 300 {
 301         struct tm t;
 302
 303         memset(&t, 0, sizeof(t));
 304
 305         if (strptime(date, "%a, %d %b %Y %H:%M:%S %Z", &t) != NULL)
 306                 return timegm(&t);
 307
 308         return 0;
 309 }
 310
 311 static char * uh_file_unix2date(time_t ts, char *buf, int len)
 312 {
 313         struct tm *t = gmtime(&ts);
 314
 315         strftime(buf, len, "%a, %d %b %Y %H:%M:%S GMT", t);
 316
 317         return buf;
 318 }
 319
 320 static char *uh_file_header(struct client *cl, int idx)
 321 {
 322         if (!cl->dispatch.file.hdr[idx])
 323                 return NULL;
 324
 325         return (char *) blobmsg_data(cl->dispatch.file.hdr[idx]);
 326 }
 327
 328 static void uh_file_response_ok_hdrs(struct client *cl, struct stat *s)
 329 {
 330         char buf[128];
 331
 332         if (s) {
 333                 ustream_printf(cl->us, "ETag: %s\r\n", uh_file_mktag(s, buf, sizeof(buf)));
 334                 ustream_printf(cl->us, "Last-Modified: %s\r\n",
 335                                uh_file_unix2date(s->st_mtime, buf, sizeof(buf)));
 336         }
 337         ustream_printf(cl->us, "Date: %s\r\n",
 338                        uh_file_unix2date(time(NULL), buf, sizeof(buf)));
 339 }
 340
 341 static void uh_file_response_200(struct client *cl, struct stat *s)
 342 {
 343         uh_http_header(cl, 200, "OK");
 344         return uh_file_response_ok_hdrs(cl, s);
 345 }
 346
 347 static void uh_file_response_304(struct client *cl, struct stat *s)
 348 {
 349         uh_http_header(cl, 304, "Not Modified");
 350
 351         return uh_file_response_ok_hdrs(cl, s);
 352 }
 353
 354 static void uh_file_response_412(struct client *cl)
 355 {
 356         uh_http_header(cl, 412, "Precondition Failed");
 357 }
 358
 359 static bool uh_file_if_match(struct client *cl, struct stat *s)
 360 {
 361         char buf[128];
 362         const char *tag = uh_file_mktag(s, buf, sizeof(buf));
 363         char *hdr = uh_file_header(cl, HDR_IF_MATCH);
 364         char *p;
 365         int i;
 366
 367         if (!hdr)
 368                 return true;
 369
 370         p = &hdr[0];
 371         for (i = 0; i < strlen(hdr); i++)
 372         {
 373                 if ((hdr[i] == ' ') || (hdr[i] == ',')) {
 374                         hdr[i++] = 0;
 375                         p = &hdr[i];
 376                 } else if (!strcmp(p, "*") || !strcmp(p, tag)) {
 377                         return true;
 378                 }
 379         }
 380
 381         uh_file_response_412(cl);
 382         return false;
 383 }
 384
 385 static int uh_file_if_modified_since(struct client *cl, struct stat *s)
 386 {
 387         char *hdr = uh_file_header(cl, HDR_IF_MODIFIED_SINCE);
 388
 389         if (!hdr)
 390                 return true;
 391
 392         if (uh_file_date2unix(hdr) >= s->st_mtime) {
 393                 uh_file_response_304(cl, s);
 394                 return false;
 395         }
 396
 397         return true;
 398 }
 399
 400 static int uh_file_if_none_match(struct client *cl, struct stat *s)
 401 {
 402         char buf[128];
 403         const char *tag = uh_file_mktag(s, buf, sizeof(buf));
 404         char *hdr = uh_file_header(cl, HDR_IF_NONE_MATCH);
 405         char *p;
 406         int i;
 407
 408         if (!hdr)
 409                 return true;
 410
 411         p = &hdr[0];
 412         for (i = 0; i < strlen(hdr); i++) {
 413                 if ((hdr[i] == ' ') || (hdr[i] == ',')) {
 414                         hdr[i++] = 0;
 415                         p = &hdr[i];
 416                 } else if (!strcmp(p, "*") || !strcmp(p, tag)) {
 417                         if ((cl->request.method == UH_HTTP_MSG_GET) ||
 418                                 (cl->request.method == UH_HTTP_MSG_HEAD))
 419                                 uh_file_response_304(cl, s);
 420                         else
 421                                 uh_file_response_412(cl);
 422
 423                         return false;
 424                 }
 425         }
 426
 427         return true;
 428 }
 429
 430 static int uh_file_if_range(struct client *cl, struct stat *s)
 431 {
 432         char *hdr = uh_file_header(cl, HDR_IF_RANGE);
 433
 434         if (hdr) {
 435                 uh_file_response_412(cl);
 436                 return false;
 437         }
 438
 439         return true;
 440 }
 441
 442 static int uh_file_if_unmodified_since(struct client *cl, struct stat *s)
 443 {
 444         char *hdr = uh_file_header(cl, HDR_IF_UNMODIFIED_SINCE);
 445
 446         if (hdr && uh_file_date2unix(hdr) <= s->st_mtime) {
 447                 uh_file_response_412(cl);
 448                 return false;
 449         }
 450
 451         return true;
 452 }
 453
 454 static int dirent_cmp(const struct dirent **a, const struct dirent **b)
 455 {
 456         bool dir_a = !!((*a)->d_type & DT_DIR);
 457         bool dir_b = !!((*b)->d_type & DT_DIR);
 458
 459         /* directories first */
 460         if (dir_a != dir_b)
 461                 return dir_b - dir_a;
 462
 463         return alphasort(a, b);
 464 }
 465
 466 static void list_entries(struct client *cl, struct dirent **files, int count,
 467                          const char *path, char *local_path)
 468 {
 469         const char *suffix = "/";
 470         const char *type = "directory";
 471         unsigned int mode = S_IXOTH;
 472         struct stat s;
 473         char *file;
 474         char buf[128];
 475         int i;
 476
 477         file = local_path + strlen(local_path);
 478         for (i = 0; i < count; i++) {
 479                 const char *name = files[i]->d_name;
 480                 bool dir = !!(files[i]->d_type & DT_DIR);
 481
 482                 if (name[0] == '.' && name[1] == 0)
 483                         goto next;
 484
 485                 sprintf(file, "%s", name);
 486                 if (stat(local_path, &s))
 487                         goto next;
 488
 489                 if (!dir) {
 490                         suffix = "";
 491                         mode = S_IROTH;
 492                         type = uh_file_mime_lookup(local_path);
 493                 }
 494
 495                 if (!(s.st_mode & mode))
 496                         goto next;
 497
 498                 uh_chunk_printf(cl,
 499                                 "<li><strong><a href='%s%s%s'>%s</a>%s"
 500                                 "</strong><br /><small>modified: %s"
 501                                 "<br />%s - %.02f kbyte<br />"
 502                                 "<br /></small></li>",
 503                                 path, name, suffix,
 504                                 name, suffix,
 505                                 uh_file_unix2date(s.st_mtime, buf, sizeof(buf)),
 506                                 type, s.st_size / 1024.0);
 507
 508                 *file = 0;
 509 next:
 510                 free(files[i]);
 511         }
 512 }
 513
 514 static void uh_file_dirlist(struct client *cl, struct path_info *pi)
 515 {
 516         struct dirent **files = NULL;
 517         int count = 0;
 518
 519         uh_file_response_200(cl, NULL);
 520         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 521
 522         uh_chunk_printf(cl,
 523                 "<html><head><title>Index of %s</title></head>"
 524                 "<body><h1>Index of %s</h1><hr /><ol>",
 525                 pi->name, pi->name);
 526
 527         count = scandir(pi->phys, &files, NULL, dirent_cmp);
 528         if (count > 0) {
 529                 strcpy(uh_buf, pi->phys);
 530                 list_entries(cl, files, count, pi->name, uh_buf);
 531         }
 532         free(files);
 533
 534         uh_chunk_printf(cl, "</ol><hr /></body></html>");
 535         uh_request_done(cl);
 536 }
 537
 538 static void file_write_cb(struct client *cl)
 539 {
 540         int fd = cl->dispatch.file.fd;
 541         int r;
 542
 543         while (cl->us->w.data_bytes < 256) {
 544                 r = read(fd, uh_buf, sizeof(uh_buf));
 545                 if (r < 0) {
 546                         if (errno == EINTR)
 547                                 continue;
 548                 }
 549
 550                 if (!r) {
 551                         uh_request_done(cl);
 552                         return;
 553                 }
 554
 555                 uh_chunk_write(cl, uh_buf, r);
 556         }
 557 }
 558
 559 static void uh_file_free(struct client *cl)
 560 {
 561         close(cl->dispatch.file.fd);
 562 }
 563
 564 static void uh_file_data(struct client *cl, struct path_info *pi, int fd)
 565 {
 566         /* test preconditions */
 567         if (!uh_file_if_modified_since(cl, &pi->stat) ||
 568                 !uh_file_if_match(cl, &pi->stat) ||
 569                 !uh_file_if_range(cl, &pi->stat) ||
 570                 !uh_file_if_unmodified_since(cl, &pi->stat) ||
 571                 !uh_file_if_none_match(cl, &pi->stat)) {
 572                 ustream_printf(cl->us, "\r\n");
 573                 uh_request_done(cl);
 574                 close(fd);
 575                 return;
 576         }
 577
 578         /* write status */
 579         uh_file_response_200(cl, &pi->stat);
 580
 581         ustream_printf(cl->us, "Content-Type: %s\r\n",
 582                            uh_file_mime_lookup(pi->name));
 583
 584         ustream_printf(cl->us, "Content-Length: %" PRIu64 "\r\n\r\n",
 585                            pi->stat.st_size);
 586
 587
 588         /* send body */
 589         if (cl->request.method == UH_HTTP_MSG_HEAD) {
 590                 uh_request_done(cl);
 591                 close(fd);
 592                 return;
 593         }
 594
 595         cl->dispatch.file.fd = fd;
 596         cl->dispatch.write_cb = file_write_cb;
 597         cl->dispatch.free = uh_file_free;
 598         cl->dispatch.close_fds = uh_file_free;
 599         file_write_cb(cl);
 600 }
 601
 602 static bool __handle_file_request(struct client *cl, char *url);
 603
 604 static void uh_file_request(struct client *cl, const char *url,
 605                             struct path_info *pi, struct blob_attr **tb)
 606 {
 607         int fd;
 608         struct http_request *req = &cl->request;
 609         char *error_handler;
 610
 611         if (!(pi->stat.st_mode & S_IROTH))
 612                 goto error;
 613
 614         if (pi->stat.st_mode & S_IFREG) {
 615                 fd = open(pi->phys, O_RDONLY);
 616                 if (fd < 0)
 617                         goto error;
 618
 619                 req->disable_chunked = true;
 620                 cl->dispatch.file.hdr = tb;
 621                 uh_file_data(cl, pi, fd);
 622                 cl->dispatch.file.hdr = NULL;
 623                 return;
 624         }
 625
 626         if ((pi->stat.st_mode & S_IFDIR)) {
 627                 if (conf.no_dirlists)
 628                         goto error;
 629
 630                 uh_file_dirlist(cl, pi);
 631                 return;
 632         }
 633
 634 error:
 635         /* check for a previously set 403 redirect status to prevent infinite
 636            recursion when the error page itself lacks sufficient permissions */
 637         if (conf.error_handler && req->redirect_status != 403) {
 638                 req->redirect_status = 403;
 639                 error_handler = alloca(strlen(conf.error_handler) + 1);
 640                 strcpy(error_handler, conf.error_handler);
 641                 if (__handle_file_request(cl, error_handler))
 642                         return;
 643         }
 644
 645         uh_client_error(cl, 403, "Forbidden",
 646                         "You don't have permission to access %s on this server.",
 647                         url);
 648 }
 649
 650 void uh_dispatch_add(struct dispatch_handler *d)
 651 {
 652         list_add_tail(&d->list, &dispatch_handlers);
 653 }
 654
 655 static struct dispatch_handler *
 656 dispatch_find(const char *url, struct path_info *pi)
 657 {
 658         struct dispatch_handler *d;
 659
 660         list_for_each_entry(d, &dispatch_handlers, list) {
 661                 if (pi) {
 662                         if (d->check_url)
 663                                 continue;
 664
 665                         if (d->check_path(pi, url))
 666                                 return d;
 667                 } else {
 668                         if (d->check_path)
 669                                 continue;
 670
 671                         if (d->check_url(url))
 672                                 return d;
 673                 }
 674         }
 675
 676         return NULL;
 677 }
 678
 679 static void
 680 uh_invoke_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
 681 {
 682         char *url = blobmsg_data(blob_data(cl->hdr.head));
 683
 684         n_requests++;
 685         d->handle_request(cl, url, pi);
 686 }
 687
 688 static void uh_complete_request(struct client *cl)
 689 {
 690         struct deferred_request *dr;
 691
 692         n_requests--;
 693
 694         while (!list_empty(&pending_requests)) {
 695                 if (n_requests >= conf.max_script_requests)
 696                         return;
 697
 698                 dr = list_first_entry(&pending_requests, struct deferred_request, list);
 699                 list_del(&dr->list);
 700
 701                 cl = dr->cl;
 702                 dr->called = true;
 703                 cl->dispatch.data_blocked = false;
 704                 uh_invoke_script(cl, dr->d, dr->path ? &dr->pi : NULL);
 705                 client_poll_post_data(cl);
 706         }
 707 }
 708
 709
 710 static void
 711 uh_free_pending_request(struct client *cl)
 712 {
 713         struct deferred_request *dr = cl->dispatch.req_data;
 714
 715         if (dr->called)
 716                 uh_complete_request(cl);
 717         else
 718                 list_del(&dr->list);
 719         free(dr);
 720 }
 721
 722 static int field_len(const char *ptr)
 723 {
 724         if (!ptr)
 725                 return 0;
 726
 727         return strlen(ptr) + 1;
 728 }
 729
 730 #define path_info_fields \
 731         _field(root) \
 732         _field(phys) \
 733         _field(name) \
 734         _field(info) \
 735         _field(query) \
 736         _field(auth)
 737
 738 static void
 739 uh_defer_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
 740 {
 741         struct deferred_request *dr;
 742         char *_root, *_phys, *_name, *_info, *_query, *_auth;
 743
 744         cl->dispatch.req_free = uh_free_pending_request;
 745
 746         if (pi) {
 747                 /* allocate enough memory to duplicate all path_info strings in one block */
 748 #undef _field
 749 #define _field(_name) &_##_name, field_len(pi->_name),
 750                 dr = calloc_a(sizeof(*dr), path_info_fields NULL);
 751
 752                 memcpy(&dr->pi, pi, sizeof(*pi));
 753                 dr->path = true;
 754
 755                 /* copy all path_info strings */
 756 #undef _field
 757 #define _field(_name) if (pi->_name) dr->pi._name = strcpy(_##_name, pi->_name);
 758                 path_info_fields
 759         } else {
 760                 dr = calloc(1, sizeof(*dr));
 761         }
 762
 763         cl->dispatch.req_data = dr;
 764         cl->dispatch.data_blocked = true;
 765         dr->cl = cl;
 766         dr->d = d;
 767         list_add(&dr->list, &pending_requests);
 768 }
 769
 770 static void
 771 uh_invoke_handler(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 772 {
 773         if (!d->script)
 774                 return d->handle_request(cl, url, pi);
 775
 776         if (n_requests >= conf.max_script_requests)
 777                 return uh_defer_script(cl, d, pi);
 778
 779         cl->dispatch.req_free = uh_complete_request;
 780         uh_invoke_script(cl, d, pi);
 781 }
 782
 783 static bool __handle_file_request(struct client *cl, char *url)
 784 {
 785         static const struct blobmsg_policy hdr_policy[__HDR_MAX] = {
 786                 [HDR_AUTHORIZATION] = { "authorization", BLOBMSG_TYPE_STRING },
 787                 [HDR_IF_MODIFIED_SINCE] = { "if-modified-since", BLOBMSG_TYPE_STRING },
 788                 [HDR_IF_UNMODIFIED_SINCE] = { "if-unmodified-since", BLOBMSG_TYPE_STRING },
 789                 [HDR_IF_MATCH] = { "if-match", BLOBMSG_TYPE_STRING },
 790                 [HDR_IF_NONE_MATCH] = { "if-none-match", BLOBMSG_TYPE_STRING },
 791                 [HDR_IF_RANGE] = { "if-range", BLOBMSG_TYPE_STRING },
 792         };
 793         struct dispatch_handler *d;
 794         struct blob_attr *tb[__HDR_MAX];
 795         struct path_info *pi;
 796
 797         pi = uh_path_lookup(cl, url);
 798         if (!pi)
 799                 return false;
 800
 801         if (pi->redirected)
 802                 return true;
 803
 804         blobmsg_parse(hdr_policy, __HDR_MAX, tb, blob_data(cl->hdr.head), blob_len(cl->hdr.head));
 805         if (tb[HDR_AUTHORIZATION])
 806                 pi->auth = blobmsg_data(tb[HDR_AUTHORIZATION]);
 807
 808         if (!uh_auth_check(cl, pi))
 809                 return true;
 810
 811         d = dispatch_find(url, pi);
 812         if (d)
 813                 uh_invoke_handler(cl, d, url, pi);
 814         else
 815                 uh_file_request(cl, url, pi, tb);
 816
 817         return true;
 818 }
 819
 820 static char *uh_handle_alias(char *old_url)
 821 {
 822         struct alias *alias;
 823         static char *new_url;
 824         static int url_len;
 825
 826         if (!list_empty(&conf.cgi_alias)) list_for_each_entry(alias, &conf.cgi_alias, list) {
 827                 int old_len;
 828                 int new_len;
 829                 int path_len = 0;
 830
 831                 if (!uh_path_match(alias->alias, old_url))
 832                         continue;
 833
 834                 if (alias->path)
 835                         path_len = strlen(alias->path);
 836
 837                 old_len = strlen(old_url) + 1;
 838                 new_len = old_len + MAX(conf.cgi_prefix_len, path_len);
 839
 840                 if (new_len > url_len) {
 841                         new_url = realloc(new_url, new_len);
 842                         url_len = new_len;
 843                 }
 844
 845                 *new_url = '\0';
 846
 847                 if (alias->path)
 848                         strcpy(new_url, alias->path);
 849                 else if (conf.cgi_prefix)
 850                         strcpy(new_url, conf.cgi_prefix);
 851                 strcat(new_url, old_url);
 852
 853                 return new_url;
 854         }
 855         return old_url;
 856 }
 857
 858 void uh_handle_request(struct client *cl)
 859 {
 860         struct http_request *req = &cl->request;
 861         struct dispatch_handler *d;
 862         char *url = blobmsg_data(blob_data(cl->hdr.head));
 863         char *error_handler;
 864
 865         url = uh_handle_alias(url);
 866
 867         uh_handler_run(cl, &url, false);
 868         if (!url)
 869                 return;
 870
 871         req->redirect_status = 200;
 872         d = dispatch_find(url, NULL);
 873         if (d)
 874                 return uh_invoke_handler(cl, d, url, NULL);
 875
 876         if (__handle_file_request(cl, url))
 877                 return;
 878
 879         if (uh_handler_run(cl, &url, true) &&
 880             (!url || __handle_file_request(cl, url)))
 881                 return;
 882
 883         req->redirect_status = 404;
 884         if (conf.error_handler) {
 885                 error_handler = alloca(strlen(conf.error_handler) + 1);
 886                 strcpy(error_handler, conf.error_handler);
 887                 if (__handle_file_request(cl, error_handler))
 888                         return;
 889         }
 890
 891         uh_client_error(cl, 404, "Not Found", "The requested URL %s was not found on this server.", url);
 892 }