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         const 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 #define ensure_ret(x) \
 101         do { if( x < 0 ) return; } while(0)
 102
 103 static void uh_file_response_ok_hdrs(struct client *cl, struct http_request *req, struct stat *s)
 104 {
 105         ensure_ret(uh_http_sendf(cl, NULL, "Connection: close\r\n"));
 106
 107         if( s )
 108         {
 109                 ensure_ret(uh_http_sendf(cl, NULL, "ETag: %s\r\n", uh_file_mktag(s)));
 110                 ensure_ret(uh_http_sendf(cl, NULL, "Last-Modified: %s\r\n", uh_file_unix2date(s->st_mtime)));
 111         }
 112
 113         ensure_ret(uh_http_sendf(cl, NULL, "Date: %s\r\n", uh_file_unix2date(time(NULL))));
 114 }
 115
 116 static void uh_file_response_200(struct client *cl, struct http_request *req, struct stat *s)
 117 {
 118         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 200 OK\r\n", req->version));
 119         uh_file_response_ok_hdrs(cl, req, s);
 120 }
 121
 122 static void uh_file_response_304(struct client *cl, struct http_request *req, struct stat *s)
 123 {
 124         ensure_ret(uh_http_sendf(cl, NULL, "HTTP/%.1f 304 Not Modified\r\n", req->version));
 125         uh_file_response_ok_hdrs(cl, req, s);
 126 }
 127
 128 static void uh_file_response_412(struct client *cl, struct http_request *req)
 129 {
 130         ensure_ret(uh_http_sendf(cl, NULL,
 131                 "HTTP/%.1f 412 Precondition Failed\r\n"
 132                 "Connection: close\r\n", req->version));
 133 }
 134
 135 static int uh_file_if_match(struct client *cl, struct http_request *req, struct stat *s)
 136 {
 137         const char *tag = uh_file_mktag(s);
 138         char *hdr = uh_file_header_lookup(req, "If-Match");
 139         char *p;
 140         int i;
 141
 142         if( hdr )
 143         {
 144                 p = &hdr[0];
 145
 146                 for( i = 0; i < strlen(hdr); i++ )
 147                 {
 148                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 149                         {
 150                                 hdr[i++] = 0;
 151                                 p = &hdr[i];
 152                         }
 153                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 154                         {
 155                                 return 1;
 156                         }
 157                 }
 158
 159                 uh_file_response_412(cl, req);
 160                 return 0;
 161         }
 162
 163         return 1;
 164 }
 165
 166 static int uh_file_if_modified_since(struct client *cl, struct http_request *req, struct stat *s)
 167 {
 168         char *hdr = uh_file_header_lookup(req, "If-Modified-Since");
 169
 170         if( hdr )
 171         {
 172                 if( uh_file_date2unix(hdr) < s->st_mtime )
 173                 {
 174                         return 1;
 175                 }
 176                 else
 177                 {
 178                         uh_file_response_304(cl, req, s);
 179                         return 0;
 180                 }
 181         }
 182
 183         return 1;
 184 }
 185
 186 static int uh_file_if_none_match(struct client *cl, struct http_request *req, struct stat *s)
 187 {
 188         const char *tag = uh_file_mktag(s);
 189         char *hdr = uh_file_header_lookup(req, "If-None-Match");
 190         char *p;
 191         int i;
 192
 193         if( hdr )
 194         {
 195                 p = &hdr[0];
 196
 197                 for( i = 0; i < strlen(hdr); i++ )
 198                 {
 199                         if( (hdr[i] == ' ') || (hdr[i] == ',') )
 200                         {
 201                                 hdr[i++] = 0;
 202                                 p = &hdr[i];
 203                         }
 204                         else if( !strcmp(p, "*") || !strcmp(p, tag) )
 205                         {
 206                                 if( (req->method == UH_HTTP_MSG_GET) ||
 207                                     (req->method == UH_HTTP_MSG_HEAD) )
 208                                         uh_file_response_304(cl, req, s);
 209                                 else
 210                                         uh_file_response_412(cl, req);
 211
 212                                 return 0;
 213                         }
 214                 }
 215         }
 216
 217         return 1;
 218 }
 219
 220 static int uh_file_if_range(struct client *cl, struct http_request *req, struct stat *s)
 221 {
 222         char *hdr = uh_file_header_lookup(req, "If-Range");
 223
 224         if( hdr )
 225         {
 226                 uh_file_response_412(cl, req);
 227                 return 0;
 228         }
 229
 230         return 1;
 231 }
 232
 233 static int uh_file_if_unmodified_since(struct client *cl, struct http_request *req, struct stat *s)
 234 {
 235         char *hdr = uh_file_header_lookup(req, "If-Unmodified-Since");
 236
 237         if( hdr )
 238         {
 239                 if( uh_file_date2unix(hdr) <= s->st_mtime )
 240                 {
 241                         uh_file_response_412(cl, req);
 242                         return 0;
 243                 }
 244         }
 245
 246         return 1;
 247 }
 248
 249
 250 #define ensure_out(x) \
 251         do { if( x < 0 ) goto out; } while(0)
 252
 253 static int uh_file_scandir_filter_dir(const struct dirent *e)
 254 {
 255         return strcmp(e->d_name, ".") ? 1 : 0;
 256 }
 257
 258 static void uh_file_dirlist(struct client *cl, struct http_request *req, struct path_info *pi)
 259 {
 260         int i;
 261         int count = 0;
 262         char filename[PATH_MAX];
 263         char *pathptr;
 264         struct dirent **files = NULL;
 265         struct stat s;
 266
 267         ensure_out(uh_http_sendf(cl, req,
 268                 "<html><head><title>Index of %s</title></head>"
 269                 "<body><h1>Index of %s</h1><hr /><ol>",
 270                         pi->name, pi->name
 271         ));
 272
 273         if( (count = scandir(pi->phys, &files, uh_file_scandir_filter_dir, alphasort)) > 0 )
 274         {
 275                 memset(filename, 0, sizeof(filename));
 276                 memcpy(filename, pi->phys, sizeof(filename));
 277                 pathptr = &filename[strlen(filename)];
 278
 279                 /* list subdirs */
 280                 for( i = 0; i < count; i++ )
 281                 {
 282                         strncat(filename, files[i]->d_name,
 283                                 sizeof(filename) - strlen(files[i]->d_name));
 284
 285                         if( !stat(filename, &s) &&
 286                             (s.st_mode & S_IFDIR) && (s.st_mode & S_IXOTH)
 287                         )
 288                                 ensure_out(uh_http_sendf(cl, req,
 289                                         "<li><strong><a href='%s%s'>%s</a>/</strong><br />"
 290                                         "<small>modified: %s<br />directory - %.02f kbyte"
 291                                         "<br /><br /></small></li>",
 292                                                 pi->name, files[i]->d_name, files[i]->d_name,
 293                                                 uh_file_unix2date(s.st_mtime), s.st_size / 1024.0
 294                                 ));
 295
 296                         *pathptr = 0;
 297                 }
 298
 299                 /* list files */
 300                 for( i = 0; i < count; i++ )
 301                 {
 302                         strncat(filename, files[i]->d_name,
 303                                 sizeof(filename) - strlen(files[i]->d_name));
 304
 305                         if( !stat(filename, &s) &&
 306                             !(s.st_mode & S_IFDIR) && (s.st_mode & S_IROTH)
 307                         )
 308                                 ensure_out(uh_http_sendf(cl, req,
 309                                         "<li><strong><a href='%s%s'>%s</a></strong><br />"
 310                                         "<small>modified: %s<br />%s - %.02f kbyte<br />"
 311                                         "<br /></small></li>",
 312                                                 pi->name, files[i]->d_name, files[i]->d_name,
 313                                                 uh_file_unix2date(s.st_mtime),
 314                                                 uh_file_mime_lookup(filename), s.st_size / 1024.0
 315                                 ));
 316
 317                         *pathptr = 0;
 318                 }
 319         }
 320
 321         ensure_out(uh_http_sendf(cl, req, "</ol><hr /></body></html>"));
 322         ensure_out(uh_http_sendf(cl, req, ""));
 323
 324 out:
 325         if( files )
 326         {
 327                 for( i = 0; i < count; i++ )
 328                         free(files[i]);
 329
 330                 free(files);
 331         }
 332 }
 333
 334
 335 void uh_file_request(struct client *cl, struct http_request *req, struct path_info *pi)
 336 {
 337         int rlen;
 338         int fd = -1;
 339         char buf[UH_LIMIT_MSGHEAD];
 340
 341         /* we have a file */
 342         if( (pi->stat.st_mode & S_IFREG) && ((fd = open(pi->phys, O_RDONLY)) > 0) )
 343         {
 344                 /* test preconditions */
 345                 if(
 346                         uh_file_if_modified_since(cl, req, &pi->stat)   &&
 347                         uh_file_if_match(cl, req, &pi->stat)            &&
 348                         uh_file_if_range(cl, req, &pi->stat)            &&
 349                         uh_file_if_unmodified_since(cl, req, &pi->stat) &&
 350                         uh_file_if_none_match(cl, req, &pi->stat)
 351                 ) {
 352                         /* write status */
 353                         uh_file_response_200(cl, req, &pi->stat);
 354
 355                         ensure_out(uh_http_sendf(cl, NULL, "Content-Type: %s\r\n", uh_file_mime_lookup(pi->name)));
 356                         ensure_out(uh_http_sendf(cl, NULL, "Content-Length: %i\r\n", pi->stat.st_size));
 357
 358                         /* if request was HTTP 1.1 we'll respond chunked */
 359                         if( (req->version > 1.0) && (req->method != UH_HTTP_MSG_HEAD) )
 360                                 ensure_out(uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1));
 361
 362                         /* close header */
 363                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 364
 365                         /* send body */
 366                         if( req->method != UH_HTTP_MSG_HEAD )
 367                         {
 368                                 /* pump file data */
 369                                 while( (rlen = read(fd, buf, sizeof(buf))) > 0 )
 370                                         ensure_out(uh_http_send(cl, req, buf, rlen));
 371
 372                                 /* send trailer in chunked mode */
 373                                 ensure_out(uh_http_send(cl, req, "", 0));
 374                         }
 375                 }
 376
 377                 /* one of the preconditions failed, terminate opened header and exit */
 378                 else
 379                 {
 380                         ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
 381                 }
 382         }
 383
 384         /* directory */
 385         else if( (pi->stat.st_mode & S_IFDIR) && !cl->server->conf->no_dirlists )
 386         {
 387                 /* write status */
 388                 uh_file_response_200(cl, req, NULL);
 389
 390                 if( req->version > 1.0 )
 391                         ensure_out(uh_http_send(cl, NULL, "Transfer-Encoding: chunked\r\n", -1));
 392
 393                 ensure_out(uh_http_send(cl, NULL, "Content-Type: text/html\r\n\r\n", -1));
 394
 395                 /* content */
 396                 uh_file_dirlist(cl, req, pi);
 397         }
 398
 399         /* 403 */
 400         else
 401         {
 402                 ensure_out(uh_http_sendhf(cl, 403, "Forbidden",
 403                         "Access to this resource is forbidden"));
 404         }
 405
 406 out:
 407         if( fd > -1 )
 408                 close(fd);
 409 }
 410