contrib/package/uhttpd/src/uhttpd-file.c

   1 /*
   2  * uhttpd - Tiny non-forking 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         if( s )
 105         {
 106                 uh_http_sendf(cl, NULL, "ETag: %s\r\n", uh_file_mktag(s));
 107                 uh_http_sendf(cl, NULL, "Last-Modified: %s\r\n", uh_file_unix2date(s->st_mtime));
 108         }
 109
 110         uh_http_sendf(cl, NULL, "Date: %s\r\n", uh_file_unix2date(time(NULL)));
 111 }
 112
 113 static void uh_file_response_200(struct client *cl, struct http_request *req, struct stat *s)
 114 {
 115         uh_http_sendf(cl, NULL, "HTTP/%.1f 200 OK\r\n", req->version);
 116         uh_file_response_ok_hdrs(cl, req, s);
 117 }
 118
 119 static void uh_file_response_304(struct client *cl, struct http_request *req, struct stat *s)
 120 {
 121         uh_http_sendf(cl, NULL, "HTTP/%.1f 304 Not Modified\r\n", req->version);
 122         uh_file_response_ok_hdrs(cl, req, s);
 123 }
 124
 125 static void uh_file_response_412(struct client *cl, struct http_request *req)
 126 {
 127         uh_http_sendf(cl, NULL, "HTTP/%.1f 412 Precondition Failed\r\n",
 128                 req->version);
 129 }
 130
 131 static int uh_file_if_match(struct client *cl, struct http_request *req, struct stat *s)
 132 {
 133         const char *tag = uh_file_mktag(s);
 134         char *hdr = uh_file_header_lookup(req, "If-Match");
 135         char *p;
 136         int i;
 137
 138         if( hdr )
 139         {
 140                 p = &hdr[0];
 141
 142                 for( i = 0; i < strlen(hdr); i++ )
 143                 {
 144                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 145                         {
 146                                 hdr[i++] = 0;
 147                                 p = &hdr[i];
 148                         }
 149                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 150                         {
 151                                 return 1;
 152                         }
 153                 }
 154
 155                 uh_file_response_412(cl, req);
 156                 return 0;
 157         }
 158
 159         return 1;
 160 }
 161
 162 static int uh_file_if_modified_since(struct client *cl, struct http_request *req, struct stat *s)
 163 {
 164         char *hdr = uh_file_header_lookup(req, "If-Modified-Since");
 165
 166         if( hdr )
 167         {
 168                 if( uh_file_date2unix(hdr) < s->st_mtime )
 169                 {
 170                         return 1;
 171                 }
 172                 else
 173                 {
 174                         uh_file_response_304(cl, req, s);
 175                         return 0;
 176                 }
 177         }
 178
 179         return 1;
 180 }
 181
 182 static int uh_file_if_none_match(struct client *cl, struct http_request *req, struct stat *s)
 183 {
 184         const char *tag = uh_file_mktag(s);
 185         char *hdr = uh_file_header_lookup(req, "If-None-Match");
 186         char *p;
 187         int i;
 188
 189         if( hdr )
 190         {
 191                 p = &hdr[0];
 192
 193                 for( i = 0; i < strlen(hdr); i++ )
 194                 {
 195                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 196                         {
 197                                 hdr[i++] = 0;
 198                                 p = &hdr[i];
 199                         }
 200                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 201                         {
 202                                 if( (req->method == UH_HTTP_MSG_GET) ||
 203                                     (req->method == UH_HTTP_MSG_HEAD) )
 204                                         uh_file_response_304(cl, req, s);
 205                                 else
 206                                         uh_file_response_412(cl, req);
 207
 208                                 return 0;
 209                         }
 210                 }
 211         }
 212
 213         return 1;
 214 }
 215
 216 static int uh_file_if_range(struct client *cl, struct http_request *req, struct stat *s)
 217 {
 218         char *hdr = uh_file_header_lookup(req, "If-Range");
 219
 220         if( hdr )
 221         {
 222                 uh_file_response_412(cl, req);
 223                 return 0;
 224         }
 225
 226         return 1;
 227 }
 228
 229 static int uh_file_if_unmodified_since(struct client *cl, struct http_request *req, struct stat *s)
 230 {
 231         char *hdr = uh_file_header_lookup(req, "If-Unmodified-Since");
 232
 233         if( hdr )
 234         {
 235                 if( uh_file_date2unix(hdr) <= s->st_mtime )
 236                 {
 237                         uh_file_response_412(cl, req);
 238                         return 0;
 239                 }
 240         }
 241
 242         return 1;
 243 }
 244
 245
 246 static int uh_file_scandir_filter_dir(const struct dirent *e)
 247 {
 248         return strcmp(e->d_name, ".") ? 1 : 0;
 249 }
 250
 251 static void uh_file_dirlist(struct client *cl, struct http_request *req, struct path_info *pi)
 252 {
 253         int i, count;
 254         char filename[PATH_MAX];
 255         char *pathptr;
 256         struct dirent **files = NULL;
 257         struct stat s;
 258
 259         uh_http_sendf(cl, req,
 260                 "<html><head><title>Index of %s</title></head>"
 261                 "<body><h1>Index of %s</h1><hr /><ol>",
 262                         pi->name, pi->name
 263         );
 264
 265         if( (count = scandir(pi->phys, &files, uh_file_scandir_filter_dir, alphasort)) > 0 )
 266         {
 267                 memset(filename, 0, sizeof(filename));
 268                 memcpy(filename, pi->phys, sizeof(filename));
 269                 pathptr = &filename[strlen(filename)];
 270
 271                 /* list subdirs */
 272                 for( i = 0; i < count; i++ )
 273                 {
 274                         strncat(filename, files[i]->d_name,
 275                                 sizeof(filename) - strlen(files[i]->d_name));
 276
 277                         if( !stat(filename, &s) && (s.st_mode & S_IFDIR) )
 278                                 uh_http_sendf(cl, req,
 279                                         "<li><strong><a href='%s%s'>%s</a>/</strong><br />"
 280                                         "<small>modified: %s<br />directory - %.02f kbyte"
 281                                         "<br /><br /></small></li>",
 282                                                 pi->name, files[i]->d_name, files[i]->d_name,
 283                                                 uh_file_unix2date(s.st_mtime), s.st_size / 1024.0
 284                                 );
 285
 286                         *pathptr = 0;
 287                 }
 288
 289                 /* list files */
 290                 for( i = 0; i < count; i++ )
 291                 {
 292                         strncat(filename, files[i]->d_name,
 293                                 sizeof(filename) - strlen(files[i]->d_name));
 294
 295                         if( !stat(filename, &s) && !(s.st_mode & S_IFDIR) )
 296                                 uh_http_sendf(cl, req,
 297                                         "<li><strong><a href='%s%s'>%s</a></strong><br />"
 298                                         "<small>modified: %s<br />%s - %.02f kbyte<br />"
 299                                         "<br /></small></li>",
 300                                                 pi->name, files[i]->d_name, files[i]->d_name,
 301                                                 uh_file_unix2date(s.st_mtime),
 302                                                 uh_file_mime_lookup(filename), s.st_size / 1024.0
 303                                 );
 304
 305                         *pathptr = 0;
 306                         free(files[i]);
 307                 }
 308         }
 309
 310         free(files);
 311
 312         uh_http_sendf(cl, req, "</ol><hr /></body></html>");
 313         uh_http_sendf(cl, req, "");
 314 }
 315
 316
 317 void uh_file_request(struct client *cl, struct http_request *req, struct path_info *pi)
 318 {
 319         int fd, rlen;
 320         char buf[UH_LIMIT_MSGHEAD];
 321
 322         /* we have a file */
 323         if( (pi->stat.st_mode & S_IFREG) && ((fd = open(pi->phys, O_RDONLY)) > 0) )
 324         {
 325                 /* test preconditions */
 326                 if(
 327                         uh_file_if_modified_since(cl, req, &pi->stat)   &&
 328                         uh_file_if_match(cl, req, &pi->stat)            &&
 329                         uh_file_if_range(cl, req, &pi->stat)            &&
 330                         uh_file_if_unmodified_since(cl, req, &pi->stat) &&
 331                         uh_file_if_none_match(cl, req, &pi->stat)
 332                 ) {
 333                         /* write status */
 334                         uh_file_response_200(cl, req, &pi->stat);
 335
 336                         uh_http_sendf(cl, NULL, "Content-Type: %s\r\n", uh_file_mime_lookup(pi->name));
 337                         uh_http_sendf(cl, NULL, "Content-Length: %i\r\n", pi->stat.st_size);
 338
 339                         /* if request was HTTP 1.1 we'll respond chunked */
 340                         if( (req->version > 1.0) && (req->method != UH_HTTP_MSG_HEAD) )
 341                                 uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1);
 342
 343                         /* close header */
 344                         uh_http_send(cl, NULL, "\r\n", -1);
 345
 346                         /* send body */
 347                         if( req->method != UH_HTTP_MSG_HEAD )
 348                         {
 349                                 /* pump file data */
 350                                 while( (rlen = read(fd, buf, sizeof(buf))) > 0 )
 351                                 {
 352                                         uh_http_send(cl, req, buf, rlen);
 353                                 }
 354
 355                                 /* send trailer in chunked mode */
 356                                 uh_http_send(cl, req, "", 0);
 357                         }
 358                 }
 359
 360                 /* one of the preconditions failed, terminate opened header and exit */
 361                 else
 362                 {
 363                         uh_http_send(cl, NULL, "\r\n", -1);
 364                 }
 365
 366                 close(fd);
 367         }
 368
 369         /* directory */
 370         else if( pi->stat.st_mode & S_IFDIR )
 371         {
 372                 /* write status */
 373                 uh_file_response_200(cl, req, NULL);
 374
 375                 if( req->version > 1.0 )
 376                         uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1);
 377
 378                 uh_http_send(cl, NULL, "Content-Type: text/html\r\n\r\n", -1);
 379
 380                 /* content */
 381                 uh_file_dirlist(cl, req, pi);
 382         }
 383
 384         /* 403 */
 385         else
 386         {
 387                 uh_http_sendhf(cl, 403, "Forbidden",
 388                         "Access to this resource is forbidden");
 389         }
 390 }
 391