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