package/uhttpd/src/uhttpd-file.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd - Static file handler
   3  *
   4  *   Copyright (C) 2010 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         char *p, *pd, *ps;
  33
  34         ps = strrchr(path, '/');
  35         pd = strrchr(path, '.');
  36
  37         /* use either slash or dot as separator, whatever comes last */
  38         p = (ps && pd && (ps > pd)) ? ps : pd;
  39
  40         if( (p != NULL) && (*(++p) != 0) )
  41         {
  42                 while( m->extn )
  43                 {
  44                         if( ! strcasecmp(p, m->extn) )
  45                                 return m->mime;
  46
  47                         m++;
  48                 }
  49         }
  50
  51         return "application/octet-stream";
  52 }
  53
  54 static const char * uh_file_mktag(struct stat *s)
  55 {
  56         static char tag[128];
  57
  58         snprintf(tag, sizeof(tag), "\"%x-%x-%x\"",
  59                 (unsigned int) s->st_ino,
  60                 (unsigned int) s->st_size,
  61                 (unsigned int) s->st_mtime
  62         );
  63
  64         return tag;
  65 }
  66
  67 static time_t uh_file_date2unix(const char *date)
  68 {
  69         struct tm t;
  70
  71         memset(&t, 0, sizeof(t));
  72
  73         if( strptime(date, "%a, %d %b %Y %H:%M:%S %Z", &t) != NULL )
  74                 return timegm(&t);
  75
  76         return 0;
  77 }
  78
  79 static char * uh_file_unix2date(time_t ts)
  80 {
  81         static char str[128];
  82         struct tm *t = gmtime(&ts);
  83
  84         strftime(str, sizeof(str), "%a, %d %b %Y %H:%M:%S GMT", t);
  85
  86         return str;
  87 }
  88
  89 static char * uh_file_header_lookup(struct http_request *req, const char *name)
  90 {
  91         int i;
  92
  93         foreach_header(i, req->headers)
  94         {
  95                 if( ! strcasecmp(req->headers[i], name) )
  96                         return req->headers[i+1];
  97         }
  98
  99         return NULL;
 100 }
 101
 102 static void uh_file_response_ok_hdrs(struct client *cl, struct http_request *req, struct stat *s)
 103 {
 104         uh_http_sendf(cl, NULL, "Connection: close\r\n");
 105
 106         if( s )
 107         {
 108                 uh_http_sendf(cl, NULL, "ETag: %s\r\n", uh_file_mktag(s));
 109                 uh_http_sendf(cl, NULL, "Last-Modified: %s\r\n", uh_file_unix2date(s->st_mtime));
 110         }
 111
 112         uh_http_sendf(cl, NULL, "Date: %s\r\n", uh_file_unix2date(time(NULL)));
 113 }
 114
 115 static void uh_file_response_200(struct client *cl, struct http_request *req, struct stat *s)
 116 {
 117         uh_http_sendf(cl, NULL, "HTTP/%.1f 200 OK\r\n", req->version);
 118         uh_file_response_ok_hdrs(cl, req, s);
 119 }
 120
 121 static void uh_file_response_304(struct client *cl, struct http_request *req, struct stat *s)
 122 {
 123         uh_http_sendf(cl, NULL, "HTTP/%.1f 304 Not Modified\r\n", req->version);
 124         uh_file_response_ok_hdrs(cl, req, s);
 125 }
 126
 127 static void uh_file_response_412(struct client *cl, struct http_request *req)
 128 {
 129         uh_http_sendf(cl, NULL,
 130                 "HTTP/%.1f 412 Precondition Failed\r\n"
 131                 "Connection: close\r\n", req->version);
 132 }
 133
 134 static int uh_file_if_match(struct client *cl, struct http_request *req, struct stat *s)
 135 {
 136         const char *tag = uh_file_mktag(s);
 137         char *hdr = uh_file_header_lookup(req, "If-Match");
 138         char *p;
 139         int i;
 140
 141         if( hdr )
 142         {
 143                 p = &hdr[0];
 144
 145                 for( i = 0; i < strlen(hdr); i++ )
 146                 {
 147                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 148                         {
 149                                 hdr[i++] = 0;
 150                                 p = &hdr[i];
 151                         }
 152                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 153                         {
 154                                 return 1;
 155                         }
 156                 }
 157
 158                 uh_file_response_412(cl, req);
 159                 return 0;
 160         }
 161
 162         return 1;
 163 }
 164
 165 static int uh_file_if_modified_since(struct client *cl, struct http_request *req, struct stat *s)
 166 {
 167         char *hdr = uh_file_header_lookup(req, "If-Modified-Since");
 168
 169         if( hdr )
 170         {
 171                 if( uh_file_date2unix(hdr) < s->st_mtime )
 172                 {
 173                         return 1;
 174                 }
 175                 else
 176                 {
 177                         uh_file_response_304(cl, req, s);
 178                         return 0;
 179                 }
 180         }
 181
 182         return 1;
 183 }
 184
 185 static int uh_file_if_none_match(struct client *cl, struct http_request *req, struct stat *s)
 186 {
 187         const char *tag = uh_file_mktag(s);
 188         char *hdr = uh_file_header_lookup(req, "If-None-Match");
 189         char *p;
 190         int i;
 191
 192         if( hdr )
 193         {
 194                 p = &hdr[0];
 195
 196                 for( i = 0; i < strlen(hdr); i++ )
 197                 {
 198                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 199                         {
 200                                 hdr[i++] = 0;
 201                                 p = &hdr[i];
 202                         }
 203                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 204                         {
 205                                 if( (req->method == UH_HTTP_MSG_GET) ||
 206                                     (req->method == UH_HTTP_MSG_HEAD) )
 207                                         uh_file_response_304(cl, req, s);
 208                                 else
 209                                         uh_file_response_412(cl, req);
 210
 211                                 return 0;
 212                         }
 213                 }
 214         }
 215
 216         return 1;
 217 }
 218
 219 static int uh_file_if_range(struct client *cl, struct http_request *req, struct stat *s)
 220 {
 221         char *hdr = uh_file_header_lookup(req, "If-Range");
 222
 223         if( hdr )
 224         {
 225                 uh_file_response_412(cl, req);
 226                 return 0;
 227         }
 228
 229         return 1;
 230 }
 231
 232 static int uh_file_if_unmodified_since(struct client *cl, struct http_request *req, struct stat *s)
 233 {
 234         char *hdr = uh_file_header_lookup(req, "If-Unmodified-Since");
 235
 236         if( hdr )
 237         {
 238                 if( uh_file_date2unix(hdr) <= s->st_mtime )
 239                 {
 240                         uh_file_response_412(cl, req);
 241                         return 0;
 242                 }
 243         }
 244
 245         return 1;
 246 }
 247
 248
 249 static int uh_file_scandir_filter_dir(const struct dirent *e)
 250 {
 251         return strcmp(e->d_name, ".") ? 1 : 0;
 252 }
 253
 254 static void uh_file_dirlist(struct client *cl, struct http_request *req, struct path_info *pi)
 255 {
 256         int i, count;
 257         char filename[PATH_MAX];
 258         char *pathptr;
 259         struct dirent **files = NULL;
 260         struct stat s;
 261
 262         uh_http_sendf(cl, req,
 263                 "<html><head><title>Index of %s</title></head>"
 264                 "<body><h1>Index of %s</h1><hr /><ol>",
 265                         pi->name, pi->name
 266         );
 267
 268         if( (count = scandir(pi->phys, &files, uh_file_scandir_filter_dir, alphasort)) > 0 )
 269         {
 270                 memset(filename, 0, sizeof(filename));
 271                 memcpy(filename, pi->phys, sizeof(filename));
 272                 pathptr = &filename[strlen(filename)];
 273
 274                 /* list subdirs */
 275                 for( i = 0; i < count; i++ )
 276                 {
 277                         strncat(filename, files[i]->d_name,
 278                                 sizeof(filename) - strlen(files[i]->d_name));
 279
 280                         if( !stat(filename, &s) && (s.st_mode & S_IFDIR) )
 281                                 uh_http_sendf(cl, req,
 282                                         "<li><strong><a href='%s%s'>%s</a>/</strong><br />"
 283                                         "<small>modified: %s<br />directory - %.02f kbyte"
 284                                         "<br /><br /></small></li>",
 285                                                 pi->name, files[i]->d_name, files[i]->d_name,
 286                                                 uh_file_unix2date(s.st_mtime), s.st_size / 1024.0
 287                                 );
 288
 289                         *pathptr = 0;
 290                 }
 291
 292                 /* list files */
 293                 for( i = 0; i < count; i++ )
 294                 {
 295                         strncat(filename, files[i]->d_name,
 296                                 sizeof(filename) - strlen(files[i]->d_name));
 297
 298                         if( !stat(filename, &s) && !(s.st_mode & S_IFDIR) )
 299                                 uh_http_sendf(cl, req,
 300                                         "<li><strong><a href='%s%s'>%s</a></strong><br />"
 301                                         "<small>modified: %s<br />%s - %.02f kbyte<br />"
 302                                         "<br /></small></li>",
 303                                                 pi->name, files[i]->d_name, files[i]->d_name,
 304                                                 uh_file_unix2date(s.st_mtime),
 305                                                 uh_file_mime_lookup(filename), s.st_size / 1024.0
 306                                 );
 307
 308                         *pathptr = 0;
 309                         free(files[i]);
 310                 }
 311         }
 312
 313         free(files);
 314
 315         uh_http_sendf(cl, req, "</ol><hr /></body></html>");
 316         uh_http_sendf(cl, req, "");
 317 }
 318
 319
 320 void uh_file_request(struct client *cl, struct http_request *req, struct path_info *pi)
 321 {
 322         int fd, rlen;
 323         char buf[UH_LIMIT_MSGHEAD];
 324
 325         /* we have a file */
 326         if( (pi->stat.st_mode & S_IFREG) && ((fd = open(pi->phys, O_RDONLY)) > 0) )
 327         {
 328                 /* test preconditions */
 329                 if(
 330                         uh_file_if_modified_since(cl, req, &pi->stat)   &&
 331                         uh_file_if_match(cl, req, &pi->stat)            &&
 332                         uh_file_if_range(cl, req, &pi->stat)            &&
 333                         uh_file_if_unmodified_since(cl, req, &pi->stat) &&
 334                         uh_file_if_none_match(cl, req, &pi->stat)
 335                 ) {
 336                         /* write status */
 337                         uh_file_response_200(cl, req, &pi->stat);
 338
 339                         uh_http_sendf(cl, NULL, "Content-Type: %s\r\n", uh_file_mime_lookup(pi->name));
 340                         uh_http_sendf(cl, NULL, "Content-Length: %i\r\n", pi->stat.st_size);
 341
 342                         /* if request was HTTP 1.1 we'll respond chunked */
 343                         if( (req->version > 1.0) && (req->method != UH_HTTP_MSG_HEAD) )
 344                                 uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1);
 345
 346                         /* close header */
 347                         uh_http_send(cl, NULL, "\r\n", -1);
 348
 349                         /* send body */
 350                         if( req->method != UH_HTTP_MSG_HEAD )
 351                         {
 352                                 /* pump file data */
 353                                 while( (rlen = read(fd, buf, sizeof(buf))) > 0 )
 354                                 {
 355                                         if( uh_http_send(cl, req, buf, rlen) < 0 )
 356                                                 break;
 357                                 }
 358
 359                                 /* send trailer in chunked mode */
 360                                 uh_http_send(cl, req, "", 0);
 361                         }
 362                 }
 363
 364                 /* one of the preconditions failed, terminate opened header and exit */
 365                 else
 366                 {
 367                         uh_http_send(cl, NULL, "\r\n", -1);
 368                 }
 369
 370                 close(fd);
 371         }
 372
 373         /* directory */
 374         else if( pi->stat.st_mode & S_IFDIR )
 375         {
 376                 /* write status */
 377                 uh_file_response_200(cl, req, NULL);
 378
 379                 if( req->version > 1.0 )
 380                         uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1);
 381
 382                 uh_http_send(cl, NULL, "Content-Type: text/html\r\n\r\n", -1);
 383
 384                 /* content */
 385                 uh_file_dirlist(cl, req, pi);
 386         }
 387
 388         /* 403 */
 389         else
 390         {
 391                 uh_http_sendhf(cl, 403, "Forbidden",
 392                         "Access to this resource is forbidden");
 393         }
 394 }
 395