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