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 #ifndef _DEFAULT_SOURCE
  21 # define _DEFAULT_SOURCE
  22 #endif
  23
  24 #define _BSD_SOURCE
  25 #define _DARWIN_C_SOURCE
  26 #define _XOPEN_SOURCE 700
  27
  28 #include <sys/types.h>
  29 #include <sys/dir.h>
  30 #include <time.h>
  31 #include <strings.h>
  32 #include <dirent.h>
  33 #include <inttypes.h>
  34
  35 #include <libubox/blobmsg.h>
  36
  37 #include "uhttpd.h"
  38 #include "mimetypes.h"
  39
  40 #define MAX(a, b)       (((a) > (b)) ? (a) : (b))
  41
  42 static LIST_HEAD(index_files);
  43 static LIST_HEAD(dispatch_handlers);
  44 static LIST_HEAD(pending_requests);
  45 static int n_requests;
  46
  47 struct deferred_request {
  48         struct list_head list;
  49         struct dispatch_handler *d;
  50         struct client *cl;
  51         struct path_info pi;
  52         char *url;
  53         bool called, path;
  54 };
  55
  56 struct index_file {
  57         struct list_head list;
  58         const char *name;
  59 };
  60
  61 enum file_hdr {
  62         HDR_AUTHORIZATION,
  63         HDR_IF_MODIFIED_SINCE,
  64         HDR_IF_UNMODIFIED_SINCE,
  65         HDR_IF_MATCH,
  66         HDR_IF_NONE_MATCH,
  67         HDR_IF_RANGE,
  68         __HDR_MAX
  69 };
  70
  71 void uh_index_add(const char *filename)
  72 {
  73         struct index_file *idx;
  74
  75         idx = calloc(1, sizeof(*idx));
  76         idx->name = filename;
  77         list_add_tail(&idx->list, &index_files);
  78 }
  79
  80 static char * canonpath(const char *path, char *path_resolved)
  81 {
  82         const char *path_cpy = path;
  83         char *path_res = path_resolved;
  84
  85         if (conf.no_symlinks)
  86                 return realpath(path, path_resolved);
  87
  88         /* normalize */
  89         while ((*path_cpy != '\0') && (path_cpy < (path + PATH_MAX - 2))) {
  90                 if (*path_cpy != '/')
  91                         goto next;
  92
  93                 /* skip repeating / */
  94                 if (path_cpy[1] == '/') {
  95                         path_cpy++;
  96                         continue;
  97                 }
  98
  99                 /* /./ or /../ */
 100                 if (path_cpy[1] == '.') {
 101                         /* skip /./ */
 102                         if ((path_cpy[2] == '/') || (path_cpy[2] == '\0')) {
 103                                 path_cpy += 2;
 104                                 continue;
 105                         }
 106
 107                         /* collapse /x/../ */
 108                         if ((path_cpy[2] == '.') &&
 109                             ((path_cpy[3] == '/') || (path_cpy[3] == '\0'))) {
 110                                 while ((path_res > path_resolved) && (*--path_res != '/'));
 111
 112                                 path_cpy += 3;
 113                                 continue;
 114                         }
 115                 }
 116
 117 next:
 118                 *path_res++ = *path_cpy++;
 119         }
 120
 121         /* remove trailing slash if not root / */
 122         if ((path_res > (path_resolved+1)) && (path_res[-1] == '/'))
 123                 path_res--;
 124         else if (path_res == path_resolved)
 125                 *path_res++ = '/';
 126
 127         *path_res = '\0';
 128
 129         return path_resolved;
 130 }
 131
 132 /* Returns NULL on error.
 133 ** NB: improperly encoded URL should give client 400 [Bad Syntax]; returning
 134 ** NULL here causes 404 [Not Found], but that's not too unreasonable. */
 135 struct path_info *
 136 uh_path_lookup(struct client *cl, const char *url)
 137 {
 138         static char path_phys[PATH_MAX];
 139         static char path_info[PATH_MAX];
 140         static char path_query[PATH_MAX];
 141         static struct path_info p;
 142
 143         const char *docroot = conf.docroot;
 144         int docroot_len = strlen(docroot);
 145         char *pathptr = NULL;
 146         bool slash;
 147
 148         int i = 0;
 149         int len;
 150         struct stat s;
 151         struct index_file *idx;
 152
 153         /* back out early if url is undefined */
 154         if (url == NULL)
 155                 return NULL;
 156
 157         memset(&p, 0, sizeof(p));
 158         path_phys[0] = 0;
 159         path_info[0] = 0;
 160
 161         strcpy(uh_buf, docroot);
 162
 163         /* separate query string from url */
 164         if ((pathptr = strchr(url, '?')) != NULL) {
 165                 if (pathptr[1]) {
 166                         p.query = path_query;
 167                         snprintf(path_query, sizeof(path_query), "%s",
 168                                  pathptr + 1);
 169                 }
 170
 171                 /* urldecode component w/o query */
 172                 if (pathptr > url) {
 173                         if (uh_urldecode(&uh_buf[docroot_len],
 174                                          sizeof(uh_buf) - docroot_len - 1,
 175                                          url, pathptr - url ) < 0)
 176                                 return NULL;
 177                 }
 178         }
 179
 180         /* no query string, decode all of url */
 181         else if (uh_urldecode(&uh_buf[docroot_len],
 182                               sizeof(uh_buf) - docroot_len - 1,
 183                               url, strlen(url) ) < 0)
 184                 return NULL;
 185
 186         /* create canon path */
 187         len = strlen(uh_buf);
 188         slash = len && uh_buf[len - 1] == '/';
 189         len = min(len, sizeof(path_phys) - 1);
 190
 191         for (i = len; i >= 0; i--) {
 192                 char ch = uh_buf[i];
 193                 bool exists;
 194
 195                 if (ch != 0 && ch != '/')
 196                         continue;
 197
 198                 uh_buf[i] = 0;
 199                 exists = !!canonpath(uh_buf, path_phys);
 200                 uh_buf[i] = ch;
 201
 202                 if (!exists)
 203                         continue;
 204
 205                 /* test current path */
 206                 if (stat(path_phys, &p.stat))
 207                         continue;
 208
 209                 snprintf(path_info, sizeof(path_info), "%s", uh_buf + i);
 210                 break;
 211         }
 212
 213         /* check whether found path is within docroot */
 214         if (strncmp(path_phys, docroot, docroot_len) != 0 ||
 215             (path_phys[docroot_len] != 0 &&
 216              path_phys[docroot_len] != '/'))
 217                 return NULL;
 218
 219         /* is a regular file */
 220         if (p.stat.st_mode & S_IFREG) {
 221                 p.root = docroot;
 222                 p.phys = path_phys;
 223                 p.name = &path_phys[docroot_len];
 224                 p.info = path_info[0] ? path_info : NULL;
 225                 return &p;
 226         }
 227
 228         if (!(p.stat.st_mode & S_IFDIR))
 229                 return NULL;
 230
 231         if (path_info[0])
 232             return NULL;
 233
 234         pathptr = path_phys + strlen(path_phys);
 235
 236         /* ensure trailing slash */
 237         if (pathptr[-1] != '/') {
 238                 pathptr[0] = '/';
 239                 pathptr[1] = 0;
 240                 pathptr++;
 241         }
 242
 243         /* if requested url resolves to a directory and a trailing slash
 244            is missing in the request url, redirect the client to the same
 245            url with trailing slash appended */
 246         if (!slash) {
 247                 uh_http_header(cl, 302, "Found");
 248                 if (!uh_use_chunked(cl))
 249                         ustream_printf(cl->us, "Content-Length: 0\r\n");
 250                 ustream_printf(cl->us, "Location: %s%s%s\r\n\r\n",
 251                                 &path_phys[docroot_len],
 252                                 p.query ? "?" : "",
 253                                 p.query ? p.query : "");
 254                 uh_request_done(cl);
 255                 p.redirected = 1;
 256                 return &p;
 257         }
 258
 259         /* try to locate index file */
 260         len = path_phys + sizeof(path_phys) - pathptr - 1;
 261         list_for_each_entry(idx, &index_files, list) {
 262                 if (strlen(idx->name) > len)
 263                         continue;
 264
 265                 strcpy(pathptr, idx->name);
 266                 if (!stat(path_phys, &s) && (s.st_mode & S_IFREG)) {
 267                         memcpy(&p.stat, &s, sizeof(p.stat));
 268                         break;
 269                 }
 270
 271                 *pathptr = 0;
 272         }
 273
 274         p.root = docroot;
 275         p.phys = path_phys;
 276         p.name = &path_phys[docroot_len];
 277
 278         return p.phys ? &p : NULL;
 279 }
 280
 281 static const char * uh_file_mime_lookup(const char *path)
 282 {
 283         const struct mimetype *m = &uh_mime_types[0];
 284         const char *e;
 285
 286         while (m->extn) {
 287                 e = &path[strlen(path)-1];
 288
 289                 while (e >= path) {
 290                         if ((*e == '.' || *e == '/') && !strcasecmp(&e[1], m->extn))
 291                                 return m->mime;
 292
 293                         e--;
 294                 }
 295
 296                 m++;
 297         }
 298
 299         return "application/octet-stream";
 300 }
 301
 302 static const char * uh_file_mktag(struct stat *s, char *buf, int len)
 303 {
 304         snprintf(buf, len, "\"%" PRIx64 "-%" PRIx64 "-%" PRIx64 "\"",
 305                  s->st_ino, s->st_size, (uint64_t)s->st_mtime);
 306
 307         return buf;
 308 }
 309
 310 static time_t uh_file_date2unix(const char *date)
 311 {
 312         struct tm t;
 313
 314         memset(&t, 0, sizeof(t));
 315
 316         if (strptime(date, "%a, %d %b %Y %H:%M:%S %Z", &t) != NULL)
 317                 return timegm(&t);
 318
 319         return 0;
 320 }
 321
 322 static char * uh_file_unix2date(time_t ts, char *buf, int len)
 323 {
 324         struct tm *t = gmtime(&ts);
 325
 326         strftime(buf, len, "%a, %d %b %Y %H:%M:%S GMT", t);
 327
 328         return buf;
 329 }
 330
 331 static char *uh_file_header(struct client *cl, int idx)
 332 {
 333         if (!cl->dispatch.file.hdr[idx])
 334                 return NULL;
 335
 336         return (char *) blobmsg_data(cl->dispatch.file.hdr[idx]);
 337 }
 338
 339 static void uh_file_response_ok_hdrs(struct client *cl, struct stat *s)
 340 {
 341         char buf[128];
 342
 343         if (s) {
 344                 ustream_printf(cl->us, "ETag: %s\r\n", uh_file_mktag(s, buf, sizeof(buf)));
 345                 ustream_printf(cl->us, "Last-Modified: %s\r\n",
 346                                uh_file_unix2date(s->st_mtime, buf, sizeof(buf)));
 347         }
 348         ustream_printf(cl->us, "Date: %s\r\n",
 349                        uh_file_unix2date(time(NULL), buf, sizeof(buf)));
 350 }
 351
 352 static void uh_file_response_200(struct client *cl, struct stat *s)
 353 {
 354         uh_http_header(cl, 200, "OK");
 355         return uh_file_response_ok_hdrs(cl, s);
 356 }
 357
 358 static void uh_file_response_304(struct client *cl, struct stat *s)
 359 {
 360         uh_http_header(cl, 304, "Not Modified");
 361
 362         return uh_file_response_ok_hdrs(cl, s);
 363 }
 364
 365 static void uh_file_response_405(struct client *cl)
 366 {
 367         uh_http_header(cl, 405, "Method Not Allowed");
 368 }
 369
 370 static void uh_file_response_412(struct client *cl)
 371 {
 372         uh_http_header(cl, 412, "Precondition Failed");
 373 }
 374
 375 static bool uh_file_if_match(struct client *cl, struct stat *s)
 376 {
 377         char buf[128];
 378         const char *tag = uh_file_mktag(s, buf, sizeof(buf));
 379         char *hdr = uh_file_header(cl, HDR_IF_MATCH);
 380         char *p;
 381         int i;
 382
 383         if (!hdr)
 384                 return true;
 385
 386         p = &hdr[0];
 387         for (i = 0; i < strlen(hdr); i++)
 388         {
 389                 if ((hdr[i] == ' ') || (hdr[i] == ',')) {
 390                         hdr[i++] = 0;
 391                         p = &hdr[i];
 392                 } else if (!strcmp(p, "*") || !strcmp(p, tag)) {
 393                         return true;
 394                 }
 395         }
 396
 397         uh_file_response_412(cl);
 398         return false;
 399 }
 400
 401 static int uh_file_if_modified_since(struct client *cl, struct stat *s)
 402 {
 403         char *hdr = uh_file_header(cl, HDR_IF_MODIFIED_SINCE);
 404
 405         if (!hdr)
 406                 return true;
 407
 408         if (uh_file_date2unix(hdr) >= s->st_mtime) {
 409                 uh_file_response_304(cl, s);
 410                 return false;
 411         }
 412
 413         return true;
 414 }
 415
 416 static int uh_file_if_none_match(struct client *cl, struct stat *s)
 417 {
 418         char buf[128];
 419         const char *tag = uh_file_mktag(s, buf, sizeof(buf));
 420         char *hdr = uh_file_header(cl, HDR_IF_NONE_MATCH);
 421         char *p;
 422         int i;
 423
 424         if (!hdr)
 425                 return true;
 426
 427         p = &hdr[0];
 428         for (i = 0; i < strlen(hdr); i++) {
 429                 if ((hdr[i] == ' ') || (hdr[i] == ',')) {
 430                         hdr[i++] = 0;
 431                         p = &hdr[i];
 432                 } else if (!strcmp(p, "*") || !strcmp(p, tag)) {
 433                         if ((cl->request.method == UH_HTTP_MSG_GET) ||
 434                                 (cl->request.method == UH_HTTP_MSG_HEAD))
 435                                 uh_file_response_304(cl, s);
 436                         else
 437                                 uh_file_response_412(cl);
 438
 439                         return false;
 440                 }
 441         }
 442
 443         return true;
 444 }
 445
 446 static int uh_file_if_range(struct client *cl, struct stat *s)
 447 {
 448         char *hdr = uh_file_header(cl, HDR_IF_RANGE);
 449
 450         if (hdr) {
 451                 uh_file_response_412(cl);
 452                 return false;
 453         }
 454
 455         return true;
 456 }
 457
 458 static int uh_file_if_unmodified_since(struct client *cl, struct stat *s)
 459 {
 460         char *hdr = uh_file_header(cl, HDR_IF_UNMODIFIED_SINCE);
 461
 462         if (hdr && uh_file_date2unix(hdr) <= s->st_mtime) {
 463                 uh_file_response_412(cl);
 464                 return false;
 465         }
 466
 467         return true;
 468 }
 469
 470 static int dirent_cmp(const struct dirent **a, const struct dirent **b)
 471 {
 472         bool dir_a = !!((*a)->d_type & DT_DIR);
 473         bool dir_b = !!((*b)->d_type & DT_DIR);
 474
 475         /* directories first */
 476         if (dir_a != dir_b)
 477                 return dir_b - dir_a;
 478
 479         return alphasort(a, b);
 480 }
 481
 482 static void list_entries(struct client *cl, struct dirent **files, int count,
 483                          const char *path, char *local_path)
 484 {
 485         const char *suffix = "/";
 486         const char *type = "directory";
 487         unsigned int mode = S_IXOTH;
 488         struct stat s;
 489         char *escaped;
 490         char *file;
 491         char buf[128];
 492         int i;
 493
 494         file = local_path + strlen(local_path);
 495         for (i = 0; i < count; i++) {
 496                 const char *name = files[i]->d_name;
 497                 bool dir = !!(files[i]->d_type & DT_DIR);
 498
 499                 if (name[0] == '.' && name[1] == 0)
 500                         goto next;
 501
 502                 sprintf(file, "%s", name);
 503                 if (stat(local_path, &s))
 504                         goto next;
 505
 506                 if (!dir) {
 507                         suffix = "";
 508                         mode = S_IROTH;
 509                         type = uh_file_mime_lookup(local_path);
 510                 }
 511
 512                 if (!(s.st_mode & mode))
 513                         goto next;
 514
 515                 escaped = uh_htmlescape(name);
 516
 517                 if (!escaped)
 518                         goto next;
 519
 520                 uh_chunk_printf(cl,
 521                                 "<li><strong><a href='%s%s%s'>%s</a>%s"
 522                                 "</strong><br /><small>modified: %s"
 523                                 "<br />%s - %.02f kbyte<br />"
 524                                 "<br /></small></li>",
 525                                 path, escaped, suffix,
 526                                 escaped, suffix,
 527                                 uh_file_unix2date(s.st_mtime, buf, sizeof(buf)),
 528                                 type, s.st_size / 1024.0);
 529
 530                 free(escaped);
 531                 *file = 0;
 532 next:
 533                 free(files[i]);
 534         }
 535 }
 536
 537 static void uh_file_dirlist(struct client *cl, struct path_info *pi)
 538 {
 539         struct dirent **files = NULL;
 540         char *escaped_path = uh_htmlescape(pi->name);
 541         int count = 0;
 542
 543         if (!escaped_path)
 544         {
 545                 uh_client_error(cl, 500, "Internal Server Error", "Out of memory");
 546                 return;
 547         }
 548
 549         uh_file_response_200(cl, NULL);
 550         ustream_printf(cl->us, "Content-Type: text/html; charset=%s\r\n\r\n",
 551                 conf.dirlist_charset ? conf.dirlist_charset : "UTF-8");
 552
 553         uh_chunk_printf(cl,
 554                 "<html><head><title>Index of %s</title></head>"
 555                 "<body><h1>Index of %s</h1><hr /><ol>",
 556                 escaped_path, escaped_path);
 557
 558         count = scandir(pi->phys, &files, NULL, dirent_cmp);
 559         if (count > 0) {
 560                 strcpy(uh_buf, pi->phys);
 561                 list_entries(cl, files, count, escaped_path, uh_buf);
 562         }
 563         free(escaped_path);
 564         free(files);
 565
 566         uh_chunk_printf(cl, "</ol><hr /></body></html>");
 567         uh_request_done(cl);
 568 }
 569
 570 static void file_write_cb(struct client *cl)
 571 {
 572         int fd = cl->dispatch.file.fd;
 573         int r;
 574
 575         while (cl->us->w.data_bytes < 256) {
 576                 r = read(fd, uh_buf, sizeof(uh_buf));
 577                 if (r < 0) {
 578                         if (errno == EINTR)
 579                                 continue;
 580                 }
 581
 582                 if (!r) {
 583                         uh_request_done(cl);
 584                         return;
 585                 }
 586
 587                 uh_chunk_write(cl, uh_buf, r);
 588         }
 589 }
 590
 591 static void uh_file_free(struct client *cl)
 592 {
 593         close(cl->dispatch.file.fd);
 594 }
 595
 596 static void uh_file_data(struct client *cl, struct path_info *pi, int fd)
 597 {
 598         /* test preconditions */
 599         if (!cl->dispatch.no_cache &&
 600             (!uh_file_if_modified_since(cl, &pi->stat) ||
 601              !uh_file_if_match(cl, &pi->stat) ||
 602              !uh_file_if_range(cl, &pi->stat) ||
 603              !uh_file_if_unmodified_since(cl, &pi->stat) ||
 604              !uh_file_if_none_match(cl, &pi->stat))) {
 605                 ustream_printf(cl->us, "\r\n");
 606                 uh_request_done(cl);
 607                 close(fd);
 608                 return;
 609         }
 610
 611         /* write status */
 612         uh_file_response_200(cl, &pi->stat);
 613
 614         ustream_printf(cl->us, "Content-Type: %s\r\n",
 615                            uh_file_mime_lookup(pi->name));
 616
 617         ustream_printf(cl->us, "Content-Length: %" PRIu64 "\r\n\r\n",
 618                            pi->stat.st_size);
 619
 620
 621         /* send body */
 622         if (cl->request.method == UH_HTTP_MSG_HEAD) {
 623                 uh_request_done(cl);
 624                 close(fd);
 625                 return;
 626         }
 627
 628         cl->dispatch.file.fd = fd;
 629         cl->dispatch.write_cb = file_write_cb;
 630         cl->dispatch.free = uh_file_free;
 631         cl->dispatch.close_fds = uh_file_free;
 632         file_write_cb(cl);
 633 }
 634
 635 static bool __handle_file_request(struct client *cl, char *url, bool is_error_handler);
 636
 637 static void uh_file_request(struct client *cl, const char *url,
 638                             struct path_info *pi, struct blob_attr **tb)
 639 {
 640         int fd;
 641         struct http_request *req = &cl->request;
 642         char *error_handler, *escaped_url;
 643
 644         switch (cl->request.method) {
 645         case UH_HTTP_MSG_GET:
 646         case UH_HTTP_MSG_POST:
 647         case UH_HTTP_MSG_HEAD:
 648         case UH_HTTP_MSG_OPTIONS:
 649                 break;
 650
 651         default:
 652                 uh_file_response_405(cl);
 653                 ustream_printf(cl->us, "\r\n");
 654                 uh_request_done(cl);
 655                 return;
 656         }
 657
 658         if (!(pi->stat.st_mode & S_IROTH))
 659                 goto error;
 660
 661         if (pi->stat.st_mode & S_IFREG) {
 662                 fd = open(pi->phys, O_RDONLY);
 663                 if (fd < 0)
 664                         goto error;
 665
 666                 req->disable_chunked = true;
 667                 cl->dispatch.file.hdr = tb;
 668                 uh_file_data(cl, pi, fd);
 669                 cl->dispatch.file.hdr = NULL;
 670                 return;
 671         }
 672
 673         if ((pi->stat.st_mode & S_IFDIR)) {
 674                 if (conf.no_dirlists)
 675                         goto error;
 676
 677                 uh_file_dirlist(cl, pi);
 678                 return;
 679         }
 680
 681 error:
 682         /* check for a previously set 403 redirect status to prevent infinite
 683            recursion when the error page itself lacks sufficient permissions */
 684         if (conf.error_handler && req->redirect_status != 403) {
 685                 req->redirect_status = 403;
 686                 error_handler = alloca(strlen(conf.error_handler) + 1);
 687                 strcpy(error_handler, conf.error_handler);
 688                 if (__handle_file_request(cl, error_handler, true))
 689                         return;
 690         }
 691
 692         escaped_url = uh_htmlescape(url);
 693
 694         uh_client_error(cl, 403, "Forbidden",
 695                         "You don't have permission to access %s on this server.",
 696                         escaped_url ? escaped_url : "the url");
 697
 698         if (escaped_url)
 699                 free(escaped_url);
 700 }
 701
 702 void uh_dispatch_add(struct dispatch_handler *d)
 703 {
 704         list_add_tail(&d->list, &dispatch_handlers);
 705 }
 706
 707 static struct dispatch_handler *
 708 dispatch_find(const char *url, struct path_info *pi)
 709 {
 710         struct dispatch_handler *d;
 711
 712         list_for_each_entry(d, &dispatch_handlers, list) {
 713                 if (pi) {
 714                         if (d->check_url)
 715                                 continue;
 716
 717                         if (d->check_path(pi, url))
 718                                 return d;
 719                 } else {
 720                         if (d->check_path)
 721                                 continue;
 722
 723                         if (d->check_url(url))
 724                                 return d;
 725                 }
 726         }
 727
 728         return NULL;
 729 }
 730
 731 static void
 732 uh_invoke_script(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 733 {
 734         n_requests++;
 735         d->handle_request(cl, url, pi);
 736 }
 737
 738 static void uh_complete_request(struct client *cl)
 739 {
 740         struct deferred_request *dr;
 741
 742         n_requests--;
 743
 744         while (!list_empty(&pending_requests)) {
 745                 if (n_requests >= conf.max_script_requests)
 746                         return;
 747
 748                 dr = list_first_entry(&pending_requests, struct deferred_request, list);
 749                 list_del(&dr->list);
 750
 751                 cl = dr->cl;
 752                 dr->called = true;
 753                 cl->dispatch.data_blocked = false;
 754                 uh_invoke_script(cl, dr->d, dr->url, dr->path ? &dr->pi : NULL);
 755                 client_poll_post_data(cl);
 756                 ustream_poll(cl->us);
 757         }
 758 }
 759
 760
 761 static void
 762 uh_free_pending_request(struct client *cl)
 763 {
 764         struct deferred_request *dr = cl->dispatch.req_data;
 765
 766         if (dr->called)
 767                 uh_complete_request(cl);
 768         else
 769                 list_del(&dr->list);
 770         free(dr);
 771 }
 772
 773 static int field_len(const char *ptr)
 774 {
 775         if (!ptr)
 776                 return 0;
 777
 778         return strlen(ptr) + 1;
 779 }
 780
 781 #define path_info_fields \
 782         _field(root) \
 783         _field(phys) \
 784         _field(name) \
 785         _field(info) \
 786         _field(query)
 787
 788 static void
 789 uh_defer_script(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 790 {
 791         struct deferred_request *dr;
 792         char *_url, *_root, *_phys, *_name, *_info, *_query;
 793
 794         cl->dispatch.req_free = uh_free_pending_request;
 795
 796         if (pi) {
 797                 /* allocate enough memory to duplicate all path_info strings in one block */
 798 #undef _field
 799 #define _field(_name) &_##_name, field_len(pi->_name),
 800                 dr = calloc_a(sizeof(*dr), &_url, strlen(url) + 1, path_info_fields NULL);
 801
 802                 memcpy(&dr->pi, pi, sizeof(*pi));
 803                 dr->path = true;
 804
 805                 /* copy all path_info strings */
 806 #undef _field
 807 #define _field(_name) if (pi->_name) dr->pi._name = strcpy(_##_name, pi->_name);
 808                 path_info_fields
 809         } else {
 810                 dr = calloc_a(sizeof(*dr), &_url, strlen(url) + 1, NULL);
 811         }
 812
 813         cl->dispatch.req_data = dr;
 814         cl->dispatch.data_blocked = true;
 815         dr->url = strcpy(_url, url);
 816         dr->cl = cl;
 817         dr->d = d;
 818         list_add(&dr->list, &pending_requests);
 819 }
 820
 821 static void
 822 uh_invoke_handler(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 823 {
 824         if (!d->script)
 825                 return d->handle_request(cl, url, pi);
 826
 827         if (n_requests >= conf.max_script_requests)
 828                 return uh_defer_script(cl, d, url, pi);
 829
 830         cl->dispatch.req_free = uh_complete_request;
 831         uh_invoke_script(cl, d, url, pi);
 832 }
 833
 834 static bool __handle_file_request(struct client *cl, char *url, bool is_error_handler)
 835 {
 836         static const struct blobmsg_policy hdr_policy[__HDR_MAX] = {
 837                 [HDR_AUTHORIZATION] = { "authorization", BLOBMSG_TYPE_STRING },
 838                 [HDR_IF_MODIFIED_SINCE] = { "if-modified-since", BLOBMSG_TYPE_STRING },
 839                 [HDR_IF_UNMODIFIED_SINCE] = { "if-unmodified-since", BLOBMSG_TYPE_STRING },
 840                 [HDR_IF_MATCH] = { "if-match", BLOBMSG_TYPE_STRING },
 841                 [HDR_IF_NONE_MATCH] = { "if-none-match", BLOBMSG_TYPE_STRING },
 842                 [HDR_IF_RANGE] = { "if-range", BLOBMSG_TYPE_STRING },
 843         };
 844         struct dispatch_handler *d;
 845         struct blob_attr *tb[__HDR_MAX];
 846         struct path_info *pi;
 847         char *user, *pass, *auth;
 848
 849         if (is_error_handler) {
 850                 d = dispatch_find(url, NULL);
 851
 852                 if (d) {
 853                         uh_invoke_handler(cl, d, url, NULL);
 854
 855                         return true;
 856                 }
 857         }
 858
 859         pi = uh_path_lookup(cl, url);
 860         if (!pi)
 861                 return false;
 862
 863         if (pi->redirected)
 864                 return true;
 865
 866         blobmsg_parse(hdr_policy, __HDR_MAX, tb, blob_data(cl->hdr.head), blob_len(cl->hdr.head));
 867
 868         auth = tb[HDR_AUTHORIZATION] ? blobmsg_data(tb[HDR_AUTHORIZATION]) : NULL;
 869
 870         if (!uh_auth_check(cl, pi->name, auth, &user, &pass))
 871                 return true;
 872
 873         if (user && pass) {
 874                 blobmsg_add_string(&cl->hdr, "http-auth-user", user);
 875                 blobmsg_add_string(&cl->hdr, "http-auth-pass", pass);
 876         }
 877
 878         d = dispatch_find(url, pi);
 879         if (d)
 880                 uh_invoke_handler(cl, d, url, pi);
 881         else
 882                 uh_file_request(cl, url, pi, tb);
 883
 884         return true;
 885 }
 886
 887 static char *uh_handle_alias(char *old_url)
 888 {
 889         struct alias *alias;
 890         static char *new_url;
 891         static int url_len;
 892
 893         if (!list_empty(&conf.cgi_alias)) list_for_each_entry(alias, &conf.cgi_alias, list) {
 894                 int old_len;
 895                 int new_len;
 896                 int path_len = 0;
 897
 898                 if (!uh_path_match(alias->alias, old_url))
 899                         continue;
 900
 901                 if (alias->path)
 902                         path_len = strlen(alias->path);
 903
 904                 old_len = strlen(old_url) + 1;
 905                 new_len = old_len + MAX(conf.cgi_prefix_len, path_len);
 906
 907                 if (new_len > url_len) {
 908                         new_url = realloc(new_url, new_len);
 909                         url_len = new_len;
 910                 }
 911
 912                 *new_url = '\0';
 913
 914                 if (alias->path)
 915                         strcpy(new_url, alias->path);
 916                 else if (conf.cgi_prefix)
 917                         strcpy(new_url, conf.cgi_prefix);
 918                 strcat(new_url, old_url);
 919
 920                 return new_url;
 921         }
 922         return old_url;
 923 }
 924
 925 void uh_handle_request(struct client *cl)
 926 {
 927         struct http_request *req = &cl->request;
 928         struct dispatch_handler *d;
 929         char *url = blobmsg_data(blob_data(cl->hdr.head));
 930         char *error_handler, *escaped_url;
 931
 932         blob_buf_init(&cl->hdr_response, 0);
 933         url = uh_handle_alias(url);
 934
 935         uh_handler_run(cl, &url, false);
 936         if (!url)
 937                 return;
 938
 939         req->redirect_status = 200;
 940         d = dispatch_find(url, NULL);
 941         if (d)
 942                 return uh_invoke_handler(cl, d, url, NULL);
 943
 944         if (__handle_file_request(cl, url, false))
 945                 return;
 946
 947         if (uh_handler_run(cl, &url, true)) {
 948                 if (!url)
 949                         return;
 950
 951                 uh_handler_run(cl, &url, false);
 952                 if (__handle_file_request(cl, url, false))
 953                         return;
 954         }
 955
 956         req->redirect_status = 404;
 957         if (conf.error_handler) {
 958                 error_handler = alloca(strlen(conf.error_handler) + 1);
 959                 strcpy(error_handler, conf.error_handler);
 960                 if (__handle_file_request(cl, error_handler, true))
 961                         return;
 962         }
 963
 964         escaped_url = uh_htmlescape(url);
 965
 966         uh_client_error(cl, 404, "Not Found", "The requested URL %s was not found on this server.",
 967                         escaped_url ? escaped_url : "");
 968
 969         if (escaped_url)
 970                 free(escaped_url);
 971 }