package/uhttpd/src/uhttpd-file.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd - Static file handler
   3  *
   4  *   Copyright (C) 2010-2011 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 http_request *req, const char *name)
  87 {
  88         int i;
  89
  90         foreach_header(i, req->headers)
  91         {
  92                 if (!strcasecmp(req->headers[i], name))
  93                         return req->headers[i+1];
  94         }
  95
  96         return NULL;
  97 }
  98
  99
 100 static int uh_file_response_ok_hdrs(struct client *cl, struct http_request *req,
 101                                                                         struct stat *s)
 102 {
 103         ensure_ret(uh_http_sendf(cl, NULL, "Connection: close\r\n"));
 104
 105         if (s)
 106         {
 107                 ensure_ret(uh_http_sendf(cl, NULL, "ETag: %s\r\n", uh_file_mktag(s)));
 108                 ensure_ret(uh_http_sendf(cl, NULL, "Last-Modified: %s\r\n",
 109                                                                  uh_file_unix2date(s->st_mtime)));
 110         }
 111
 112         return uh_http_sendf(cl, NULL, "Date: %s\r\n", uh_file_unix2date(time(NULL)));
 113 }
 114
 115 static int uh_file_response_200(struct client *cl, struct http_request *req,
 116                                                                 struct stat *s)
 117 {
 118         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 200 OK\r\n", req->version));
 119         return uh_file_response_ok_hdrs(cl, req, s);
 120 }
 121
 122 static int uh_file_response_304(struct client *cl, struct http_request *req,
 123                                                                 struct stat *s)
 124 {
 125         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 304 Not Modified\r\n", req->version));
 126         return uh_file_response_ok_hdrs(cl, req, s);
 127 }
 128
 129 static int uh_file_response_412(struct client *cl, struct http_request *req)
 130 {
 131         return uh_http_sendf(cl, NULL,
 132                 "HTTP/%.1f 412 Precondition Failed\r\n"
 133                 "Connection: close\r\n", req->version);
 134 }
 135
 136 static int uh_file_if_match(struct client *cl, struct http_request *req,
 137                                                         struct stat *s, int *ok)
 138 {
 139         const char *tag = uh_file_mktag(s);
 140         char *hdr = uh_file_header_lookup(req, "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, req));
 164                 return *ok;
 165         }
 166
 167         *ok = 1;
 168         return *ok;
 169 }
 170
 171 static int uh_file_if_modified_since(struct client *cl,
 172                                                                          struct http_request *req, struct stat *s,
 173                                                                          int *ok)
 174 {
 175         char *hdr = uh_file_header_lookup(req, "If-Modified-Since");
 176         *ok = 1;
 177
 178         if (hdr)
 179         {
 180                 if (uh_file_date2unix(hdr) >= s->st_mtime)
 181                 {
 182                         *ok = 0;
 183                         ensure_ret(uh_file_response_304(cl, req, s));
 184                 }
 185         }
 186
 187         return *ok;
 188 }
 189
 190 static int uh_file_if_none_match(struct client *cl, struct http_request *req,
 191                                                                  struct stat *s, int *ok)
 192 {
 193         const char *tag = uh_file_mktag(s);
 194         char *hdr = uh_file_header_lookup(req, "If-None-Match");
 195         char *p;
 196         int i;
 197         *ok = 1;
 198
 199         if (hdr)
 200         {
 201                 p = &hdr[0];
 202
 203                 for (i = 0; i < strlen(hdr); i++)
 204                 {
 205                         if ((hdr[i] == ' ') || (hdr[i] == ','))
 206                         {
 207                                 hdr[i++] = 0;
 208                                 p = &hdr[i];
 209                         }
 210                         else if (!strcmp(p, "*") || !strcmp(p, tag))
 211                         {
 212                                 *ok = 0;
 213
 214                                 if ((req->method == UH_HTTP_MSG_GET) ||
 215                                     (req->method == UH_HTTP_MSG_HEAD))
 216                                 {
 217                                         ensure_ret(uh_file_response_304(cl, req, s));
 218                                 }
 219                                 else
 220                                 {
 221                                         ensure_ret(uh_file_response_412(cl, req));
 222                                 }
 223
 224                                 break;
 225                         }
 226                 }
 227         }
 228
 229         return *ok;
 230 }
 231
 232 static int uh_file_if_range(struct client *cl, struct http_request *req,
 233                                                         struct stat *s, int *ok)
 234 {
 235         char *hdr = uh_file_header_lookup(req, "If-Range");
 236         *ok = 1;
 237
 238         if (hdr)
 239         {
 240                 *ok = 0;
 241                 ensure_ret(uh_file_response_412(cl, req));
 242         }
 243
 244         return *ok;
 245 }
 246
 247 static int uh_file_if_unmodified_since(struct client *cl,
 248                                                                            struct http_request *req, struct stat *s,
 249                                                                            int *ok)
 250 {
 251         char *hdr = uh_file_header_lookup(req, "If-Unmodified-Since");
 252         *ok = 1;
 253
 254         if (hdr)
 255         {
 256                 if (uh_file_date2unix(hdr) <= s->st_mtime)
 257                 {
 258                         *ok = 0;
 259                         ensure_ret(uh_file_response_412(cl, req));
 260                 }
 261         }
 262
 263         return *ok;
 264 }
 265
 266
 267 static int uh_file_scandir_filter_dir(const struct dirent *e)
 268 {
 269         return strcmp(e->d_name, ".") ? 1 : 0;
 270 }
 271
 272 static void uh_file_dirlist(struct client *cl, struct http_request *req,
 273                                                         struct path_info *pi)
 274 {
 275         int i;
 276         int count = 0;
 277         char filename[PATH_MAX];
 278         char *pathptr;
 279         struct dirent **files = NULL;
 280         struct stat s;
 281
 282         ensure_out(uh_http_sendf(cl, req,
 283                                                          "<html><head><title>Index of %s</title></head>"
 284                                                          "<body><h1>Index of %s</h1><hr /><ol>",
 285                                                          pi->name, pi->name));
 286
 287         if ((count = scandir(pi->phys, &files, uh_file_scandir_filter_dir,
 288                                                  alphasort)) > 0)
 289         {
 290                 memset(filename, 0, sizeof(filename));
 291                 memcpy(filename, pi->phys, sizeof(filename));
 292                 pathptr = &filename[strlen(filename)];
 293
 294                 /* list subdirs */
 295                 for (i = 0; i < count; i++)
 296                 {
 297                         strncat(filename, files[i]->d_name,
 298                                         sizeof(filename) - strlen(files[i]->d_name));
 299
 300                         if (!stat(filename, &s) &&
 301                                 (s.st_mode & S_IFDIR) && (s.st_mode & S_IXOTH))
 302                         {
 303                                 ensure_out(uh_http_sendf(cl, req,
 304                                                                                  "<li><strong><a href='%s%s'>%s</a>/"
 305                                                                                  "</strong><br /><small>modified: %s"
 306                                                                                  "<br />directory - %.02f kbyte<br />"
 307                                                                                  "<br /></small></li>",
 308                                                                                  pi->name, files[i]->d_name,
 309                                                                                  files[i]->d_name,
 310                                                                                  uh_file_unix2date(s.st_mtime),
 311                                                                                  s.st_size / 1024.0));
 312                         }
 313
 314                         *pathptr = 0;
 315                 }
 316
 317                 /* list files */
 318                 for (i = 0; i < count; i++)
 319                 {
 320                         strncat(filename, files[i]->d_name,
 321                                         sizeof(filename) - strlen(files[i]->d_name));
 322
 323                         if (!stat(filename, &s) &&
 324                                 !(s.st_mode & S_IFDIR) && (s.st_mode & S_IROTH))
 325                         {
 326                                 ensure_out(uh_http_sendf(cl, req,
 327                                                                                  "<li><strong><a href='%s%s'>%s</a>"
 328                                                                                  "</strong><br /><small>modified: %s"
 329                                                                                  "<br />%s - %.02f kbyte<br />"
 330                                                                                  "<br /></small></li>",
 331                                                                                  pi->name, files[i]->d_name,
 332                                                                                  files[i]->d_name,
 333                                                                                  uh_file_unix2date(s.st_mtime),
 334                                                                                  uh_file_mime_lookup(filename),
 335                                                                                  s.st_size / 1024.0));
 336                         }
 337
 338                         *pathptr = 0;
 339                 }
 340         }
 341
 342         ensure_out(uh_http_sendf(cl, req, "</ol><hr /></body></html>"));
 343         ensure_out(uh_http_sendf(cl, req, ""));
 344
 345 out:
 346         if (files)
 347         {
 348                 for (i = 0; i < count; i++)
 349                         free(files[i]);
 350
 351                 free(files);
 352         }
 353 }
 354
 355
 356 void uh_file_request(struct client *cl, struct http_request *req, struct path_info *pi)
 357 {
 358         int rlen;
 359         int ok = 1;
 360         int fd = -1;
 361         char buf[UH_LIMIT_MSGHEAD];
 362
 363         /* we have a file */
 364         if ((pi->stat.st_mode & S_IFREG) && ((fd = open(pi->phys, O_RDONLY)) > 0))
 365         {
 366                 /* test preconditions */
 367                 if (ok) ensure_out(uh_file_if_modified_since(cl, req, &pi->stat, &ok));
 368                 if (ok) ensure_out(uh_file_if_match(cl, req, &pi->stat, &ok));
 369                 if (ok) ensure_out(uh_file_if_range(cl, req, &pi->stat, &ok));
 370                 if (ok) ensure_out(uh_file_if_unmodified_since(cl, req, &pi->stat, &ok));
 371                 if (ok) ensure_out(uh_file_if_none_match(cl, req, &pi->stat, &ok));
 372
 373                 if (ok > 0)
 374                 {
 375                         /* write status */
 376                         ensure_out(uh_file_response_200(cl, req, &pi->stat));
 377
 378                         ensure_out(uh_http_sendf(cl, NULL, "Content-Type: %s\r\n", uh_file_mime_lookup(pi->name)));
 379                         ensure_out(uh_http_sendf(cl, NULL, "Content-Length: %i\r\n", pi->stat.st_size));
 380
 381                         /* if request was HTTP 1.1 we'll respond chunked */
 382                         if ((req->version > 1.0) && (req->method != UH_HTTP_MSG_HEAD))
 383                                 ensure_out(uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1));
 384
 385                         /* close header */
 386                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 387
 388                         /* send body */
 389                         if (req->method != UH_HTTP_MSG_HEAD)
 390                         {
 391                                 /* pump file data */
 392                                 while ((rlen = read(fd, buf, sizeof(buf))) > 0)
 393                                         ensure_out(uh_http_send(cl, req, buf, rlen));
 394
 395                                 /* send trailer in chunked mode */
 396                                 ensure_out(uh_http_send(cl, req, "", 0));
 397                         }
 398                 }
 399
 400                 /* one of the preconditions failed, terminate opened header and exit */
 401                 else
 402                 {
 403                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 404                 }
 405         }
 406
 407         /* directory */
 408         else if ((pi->stat.st_mode & S_IFDIR) && !cl->server->conf->no_dirlists)
 409         {
 410                 /* write status */
 411                 ensure_out(uh_file_response_200(cl, req, NULL));
 412
 413                 if (req->version > 1.0)
 414                         ensure_out(uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1));
 415
 416                 ensure_out(uh_http_send(cl, NULL, "Content-Type: text/html\r\n\r\n", -1));
 417
 418                 /* content */
 419                 uh_file_dirlist(cl, req, pi);
 420         }
 421
 422         /* 403 */
 423         else
 424         {
 425                 ensure_out(uh_http_sendhf(cl, 403, "Forbidden",
 426                         "Access to this resource is forbidden"));
 427         }
 428
 429 out:
 430         if (fd > -1)
 431                 close(fd);
 432 }