package/uhttpd/src/uhttpd-file.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd - Static file handler
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #define _XOPEN_SOURCE 500       /* strptime() */
  20 #define _BSD_SOURCE                     /* scandir(), timegm() */
  21
  22 #include "uhttpd.h"
  23 #include "uhttpd-utils.h"
  24 #include "uhttpd-file.h"
  25
  26 #include "uhttpd-mimetypes.h"
  27
  28
  29 static const char * uh_file_mime_lookup(const char *path)
  30 {
  31         struct mimetype *m = &uh_mime_types[0];
  32         const char *e;
  33
  34         while (m->extn)
  35         {
  36                 e = &path[strlen(path)-1];
  37
  38                 while (e >= path)
  39                 {
  40                         if ((*e == '.' || *e == '/') && !strcasecmp(&e[1], m->extn))
  41                                 return m->mime;
  42
  43                         e--;
  44                 }
  45
  46                 m++;
  47         }
  48
  49         return "application/octet-stream";
  50 }
  51
  52 static const char * uh_file_mktag(struct stat *s)
  53 {
  54         static char tag[128];
  55
  56         snprintf(tag, sizeof(tag), "\"%x-%x-%x\"",
  57                          (unsigned int) s->st_ino,
  58                          (unsigned int) s->st_size,
  59                          (unsigned int) s->st_mtime);
  60
  61         return tag;
  62 }
  63
  64 static time_t uh_file_date2unix(const char *date)
  65 {
  66         struct tm t;
  67
  68         memset(&t, 0, sizeof(t));
  69
  70         if (strptime(date, "%a, %d %b %Y %H:%M:%S %Z", &t) != NULL)
  71                 return timegm(&t);
  72
  73         return 0;
  74 }
  75
  76 static char * uh_file_unix2date(time_t ts)
  77 {
  78         static char str[128];
  79         struct tm *t = gmtime(&ts);
  80
  81         strftime(str, sizeof(str), "%a, %d %b %Y %H:%M:%S GMT", t);
  82
  83         return str;
  84 }
  85
  86 static char * uh_file_header_lookup(struct client *cl, const char *name)
  87 {
  88         int i;
  89
  90         foreach_header(i, cl->request.headers)
  91         {
  92                 if (!strcasecmp(cl->request.headers[i], name))
  93                         return cl->request.headers[i+1];
  94         }
  95
  96         return NULL;
  97 }
  98
  99
 100 static int uh_file_response_ok_hdrs(struct client *cl, struct stat *s)
 101 {
 102         ensure_ret(uh_http_sendf(cl, NULL, "Connection: close\r\n"));
 103
 104         if (s)
 105         {
 106                 ensure_ret(uh_http_sendf(cl, NULL, "ETag: %s\r\n", uh_file_mktag(s)));
 107                 ensure_ret(uh_http_sendf(cl, NULL, "Last-Modified: %s\r\n",
 108                                                                  uh_file_unix2date(s->st_mtime)));
 109         }
 110
 111         return uh_http_sendf(cl, NULL, "Date: %s\r\n", uh_file_unix2date(time(NULL)));
 112 }
 113
 114 static int uh_file_response_200(struct client *cl, struct stat *s)
 115 {
 116         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 200 OK\r\n",
 117                                                          cl->request.version));
 118
 119         return uh_file_response_ok_hdrs(cl, s);
 120 }
 121
 122 static int uh_file_response_304(struct client *cl, struct stat *s)
 123 {
 124         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 304 Not Modified\r\n",
 125                                                          cl->request.version));
 126
 127         return uh_file_response_ok_hdrs(cl, s);
 128 }
 129
 130 static int uh_file_response_412(struct client *cl)
 131 {
 132         return uh_http_sendf(cl, NULL,
 133                                                  "HTTP/%.1f 412 Precondition Failed\r\n"
 134                                                  "Connection: close\r\n", cl->request.version);
 135 }
 136
 137 static int uh_file_if_match(struct client *cl, struct stat *s, int *ok)
 138 {
 139         const char *tag = uh_file_mktag(s);
 140         char *hdr = uh_file_header_lookup(cl, "If-Match");
 141         char *p;
 142         int i;
 143
 144         if (hdr)
 145         {
 146                 p = &hdr[0];
 147
 148                 for (i = 0; i < strlen(hdr); i++)
 149                 {
 150                         if ((hdr[i] == ' ') || (hdr[i] == ','))
 151                         {
 152                                 hdr[i++] = 0;
 153                                 p = &hdr[i];
 154                         }
 155                         else if (!strcmp(p, "*") || !strcmp(p, tag))
 156                         {
 157                                 *ok = 1;
 158                                 return *ok;
 159                         }
 160                 }
 161
 162                 *ok = 0;
 163                 ensure_ret(uh_file_response_412(cl));
 164                 return *ok;
 165         }
 166
 167         *ok = 1;
 168         return *ok;
 169 }
 170
 171 static int uh_file_if_modified_since(struct client *cl, struct stat *s, int *ok)
 172 {
 173         char *hdr = uh_file_header_lookup(cl, "If-Modified-Since");
 174         *ok = 1;
 175
 176         if (hdr)
 177         {
 178                 if (uh_file_date2unix(hdr) >= s->st_mtime)
 179                 {
 180                         *ok = 0;
 181                         ensure_ret(uh_file_response_304(cl, s));
 182                 }
 183         }
 184
 185         return *ok;
 186 }
 187
 188 static int uh_file_if_none_match(struct client *cl, struct stat *s, int *ok)
 189 {
 190         const char *tag = uh_file_mktag(s);
 191         char *hdr = uh_file_header_lookup(cl, "If-None-Match");
 192         char *p;
 193         int i;
 194         *ok = 1;
 195
 196         if (hdr)
 197         {
 198                 p = &hdr[0];
 199
 200                 for (i = 0; i < strlen(hdr); i++)
 201                 {
 202                         if ((hdr[i] == ' ') || (hdr[i] == ','))
 203                         {
 204                                 hdr[i++] = 0;
 205                                 p = &hdr[i];
 206                         }
 207                         else if (!strcmp(p, "*") || !strcmp(p, tag))
 208                         {
 209                                 *ok = 0;
 210
 211                                 if ((cl->request.method == UH_HTTP_MSG_GET) ||
 212                                     (cl->request.method == UH_HTTP_MSG_HEAD))
 213                                 {
 214                                         ensure_ret(uh_file_response_304(cl, s));
 215                                 }
 216                                 else
 217                                 {
 218                                         ensure_ret(uh_file_response_412(cl));
 219                                 }
 220
 221                                 break;
 222                         }
 223                 }
 224         }
 225
 226         return *ok;
 227 }
 228
 229 static int uh_file_if_range(struct client *cl, struct stat *s, int *ok)
 230 {
 231         char *hdr = uh_file_header_lookup(cl, "If-Range");
 232         *ok = 1;
 233
 234         if (hdr)
 235         {
 236                 *ok = 0;
 237                 ensure_ret(uh_file_response_412(cl));
 238         }
 239
 240         return *ok;
 241 }
 242
 243 static int uh_file_if_unmodified_since(struct client *cl, struct stat *s,
 244                                                                            int *ok)
 245 {
 246         char *hdr = uh_file_header_lookup(cl, "If-Unmodified-Since");
 247         *ok = 1;
 248
 249         if (hdr)
 250         {
 251                 if (uh_file_date2unix(hdr) <= s->st_mtime)
 252                 {
 253                         *ok = 0;
 254                         ensure_ret(uh_file_response_412(cl));
 255                 }
 256         }
 257
 258         return *ok;
 259 }
 260
 261
 262 static int uh_file_scandir_filter_dir(const struct dirent *e)
 263 {
 264         return strcmp(e->d_name, ".") ? 1 : 0;
 265 }
 266
 267 static void uh_file_dirlist(struct client *cl, struct path_info *pi)
 268 {
 269         int i;
 270         int count = 0;
 271         char filename[PATH_MAX];
 272         char *pathptr;
 273         struct dirent **files = NULL;
 274         struct stat s;
 275
 276         ensure_out(uh_http_sendf(cl, &cl->request,
 277                                                          "<html><head><title>Index of %s</title></head>"
 278                                                          "<body><h1>Index of %s</h1><hr /><ol>",
 279                                                          pi->name, pi->name));
 280
 281         if ((count = scandir(pi->phys, &files, uh_file_scandir_filter_dir,
 282                                                  alphasort)) > 0)
 283         {
 284                 memset(filename, 0, sizeof(filename));
 285                 memcpy(filename, pi->phys, sizeof(filename));
 286                 pathptr = &filename[strlen(filename)];
 287
 288                 /* list subdirs */
 289                 for (i = 0; i < count; i++)
 290                 {
 291                         strncat(filename, files[i]->d_name,
 292                                         sizeof(filename) - strlen(files[i]->d_name));
 293
 294                         if (!stat(filename, &s) &&
 295                                 (s.st_mode & S_IFDIR) && (s.st_mode & S_IXOTH))
 296                         {
 297                                 ensure_out(uh_http_sendf(cl, &cl->request,
 298                                                                                  "<li><strong><a href='%s%s'>%s</a>/"
 299                                                                                  "</strong><br /><small>modified: %s"
 300                                                                                  "<br />directory - %.02f kbyte<br />"
 301                                                                                  "<br /></small></li>",
 302                                                                                  pi->name, files[i]->d_name,
 303                                                                                  files[i]->d_name,
 304                                                                                  uh_file_unix2date(s.st_mtime),
 305                                                                                  s.st_size / 1024.0));
 306                         }
 307
 308                         *pathptr = 0;
 309                 }
 310
 311                 /* list files */
 312                 for (i = 0; i < count; i++)
 313                 {
 314                         strncat(filename, files[i]->d_name,
 315                                         sizeof(filename) - strlen(files[i]->d_name));
 316
 317                         if (!stat(filename, &s) &&
 318                                 !(s.st_mode & S_IFDIR) && (s.st_mode & S_IROTH))
 319                         {
 320                                 ensure_out(uh_http_sendf(cl, &cl->request,
 321                                                                                  "<li><strong><a href='%s%s'>%s</a>"
 322                                                                                  "</strong><br /><small>modified: %s"
 323                                                                                  "<br />%s - %.02f kbyte<br />"
 324                                                                                  "<br /></small></li>",
 325                                                                                  pi->name, files[i]->d_name,
 326                                                                                  files[i]->d_name,
 327                                                                                  uh_file_unix2date(s.st_mtime),
 328                                                                                  uh_file_mime_lookup(filename),
 329                                                                                  s.st_size / 1024.0));
 330                         }
 331
 332                         *pathptr = 0;
 333                 }
 334         }
 335
 336         ensure_out(uh_http_sendf(cl, &cl->request, "</ol><hr /></body></html>"));
 337         ensure_out(uh_http_sendf(cl, &cl->request, ""));
 338
 339 out:
 340         if (files)
 341         {
 342                 for (i = 0; i < count; i++)
 343                         free(files[i]);
 344
 345                 free(files);
 346         }
 347 }
 348
 349
 350 bool uh_file_request(struct client *cl, struct path_info *pi)
 351 {
 352         int rlen;
 353         int ok = 1;
 354         int fd = -1;
 355         char buf[UH_LIMIT_MSGHEAD];
 356
 357         /* we have a file */
 358         if ((pi->stat.st_mode & S_IFREG) && ((fd = open(pi->phys, O_RDONLY)) > 0))
 359         {
 360                 /* test preconditions */
 361                 if (ok) ensure_out(uh_file_if_modified_since(cl, &pi->stat, &ok));
 362                 if (ok) ensure_out(uh_file_if_match(cl, &pi->stat, &ok));
 363                 if (ok) ensure_out(uh_file_if_range(cl, &pi->stat, &ok));
 364                 if (ok) ensure_out(uh_file_if_unmodified_since(cl, &pi->stat, &ok));
 365                 if (ok) ensure_out(uh_file_if_none_match(cl, &pi->stat, &ok));
 366
 367                 if (ok > 0)
 368                 {
 369                         /* write status */
 370                         ensure_out(uh_file_response_200(cl, &pi->stat));
 371
 372                         ensure_out(uh_http_sendf(cl, NULL, "Content-Type: %s\r\n",
 373                                                                          uh_file_mime_lookup(pi->name)));
 374
 375                         ensure_out(uh_http_sendf(cl, NULL, "Content-Length: %i\r\n",
 376                                                                          pi->stat.st_size));
 377
 378                         /* if request was HTTP 1.1 we'll respond chunked */
 379                         if ((cl->request.version > 1.0) &&
 380                                 (cl->request.method != UH_HTTP_MSG_HEAD))
 381                         {
 382                                 ensure_out(uh_http_send(cl, NULL,
 383                                                                                 "Transfer-Encoding: chunked\r\n", -1));
 384                         }
 385
 386                         /* close header */
 387                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 388
 389                         /* send body */
 390                         if (cl->request.method != UH_HTTP_MSG_HEAD)
 391                         {
 392                                 /* pump file data */
 393                                 while ((rlen = read(fd, buf, sizeof(buf))) > 0)
 394                                         ensure_out(uh_http_send(cl, &cl->request, buf, rlen));
 395
 396                                 /* send trailer in chunked mode */
 397                                 ensure_out(uh_http_send(cl, &cl->request, "", 0));
 398                         }
 399                 }
 400
 401                 /* one of the preconditions failed, terminate opened header and exit */
 402                 else
 403                 {
 404                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 405                 }
 406         }
 407
 408         /* directory */
 409         else if ((pi->stat.st_mode & S_IFDIR) && !cl->server->conf->no_dirlists)
 410         {
 411                 /* write status */
 412                 ensure_out(uh_file_response_200(cl, NULL));
 413
 414                 if (cl->request.version > 1.0)
 415                         ensure_out(uh_http_send(cl, NULL,
 416                                                                         "Transfer-Encoding: chunked\r\n", -1));
 417
 418                 ensure_out(uh_http_send(cl, NULL,
 419                                                                 "Content-Type: text/html\r\n\r\n", -1));
 420
 421                 /* content */
 422                 uh_file_dirlist(cl, pi);
 423         }
 424
 425         /* 403 */
 426         else
 427         {
 428                 ensure_out(uh_http_sendhf(cl, 403, "Forbidden",
 429                                                                   "Access to this resource is forbidden"));
 430         }
 431
 432 out:
 433         if (fd > -1)
 434                 close(fd);
 435
 436         return false;
 437 }