list_dir.c

   1 /*
   2  * User FTP Server
   3  * Author : C2H5OH
   4  * License: GPL v2
   5  *
   6  * list_dir.c - LIST and NLST commands implementation.
   7  *
   8  * To make Mozilla Firefox list the directory contents correctly, some research
   9  * work had to be done. That concluded in:
  10  *
  11  *     http://cr.yp.to/ftp.html
  12  *
  13  * In particular:
  14  *
  15  *     http://cr.yp.to/ftp/list/binls.html
  16  *
  17  * Only files or subdirectories are shown, the rest of items (symlinks, named
  18  * pipes, sockets...) are ignored. The following line is sent when a file is
  19  * found:
  20  *
  21  * -rw-r--r-- 1 ftp ftp       999 Mon  88 7777 filename
  22  *
  23  * In case of a subdirectory, the line is:
  24  *
  25  * drwxr-xr-x 1 ftp ftp       999 Mon  88 7777 dirname
  26  *
  27  * Where '999' is the item size, 'Mon  88 7777' is the month, day and year,
  28  * respectively, of the last modification date. Some servers display the hour
  29  * and minute when the distance between current time and last modification time
  30  * is less than six months. We don't do that as it is considered irrelevant. To
  31  * obtain a more precise value for the last modification time, let the client
  32  * send a MDTM command.
  33  *
  34  * Note that when, for some reason, directory listing is not possible, an empty
  35  * list is sent. So this error is not detected from the client, until it tries
  36  * to execute CWD.
  37  *
  38  * Also note that most clients will appreciate listings where all its items are
  39  * stat()-able.
  40  */
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <sys/socket.h>
  44 #include <netinet/in.h>
  45 #include <unistd.h>
  46 #include <dirent.h>
  47 #include <time.h>
  48 #include <string.h>
  49 #include <stdio.h>
  50
  51 #include "uftps.h"
  52
  53 /* Month names */
  54 static char month[12][4] = {
  55         "Jan\0", "Feb\0", "Mar\0", "Apr\0", "May\0", "Jun\0", "Jul\0", "Aug\0",
  56         "Sep\0", "Oct\0", "Nov\0", "Dec\0"
  57 };
  58
  59
  60 void list_dir (int full_list)
  61 {
  62         int                err;
  63         DIR               *dir;
  64         struct dirent     *dentry;
  65         struct sockaddr_in saddr;
  66         struct stat        st;
  67         struct tm          t;
  68         socklen_t          saddr_len = sizeof(saddr);
  69
  70         if (S_passive_mode)
  71                 S_data_sk = accept(S_passive_bind_sk,
  72                                    (struct sockaddr *) &saddr, &saddr_len);
  73
  74         if (S_arg != NULL && path_is_secure(S_arg)) {
  75                 /* Workaround for Konqueror and Nautilus */
  76                 if (S_arg[0] == '-')
  77                         dir = opendir(".");
  78                 else
  79                         dir = opendir(expanded_arg());
  80         } else {
  81                 dir = opendir(".");
  82         }
  83
  84         send_reply(S_cmd_sk, "150 Sending directory list.\r\n");
  85         if (dir == NULL)
  86                 goto finish;
  87
  88         /* Skip "." and "..", under Linux they are always the first two */
  89         readdir(dir);
  90         readdir(dir);
  91
  92         do {
  93                 dentry = readdir(dir);
  94                 if (dentry == NULL)
  95                         break;
  96
  97                 err = stat(dentry->d_name, &st);
  98                 if (err == -1)
  99                         continue;
 100
 101                 if (full_list) {
 102                         /* LIST */
 103                         gmtime_r(&(st.st_mtime), &t);
 104                         snprintf(AuxBuf, LINE_SIZE,
 105                                  "%s 1 ftp ftp %13lld %s %3d %4d %s\r\n",
 106                                  (S_ISDIR(st.st_mode) ? "dr-xr-xr-x"
 107                                   : "-r--r--r--"), (long long) st.st_size,
 108                                  month[t.tm_mon], t.tm_mday, t.tm_year + 1900,
 109                                  dentry->d_name);
 110                 } else {
 111                         /* NLST */
 112                         snprintf(AuxBuf, LINE_SIZE, "%s%s", dentry->d_name,
 113                                  (dentry->d_type == DT_DIR ? "/\r\n"
 114                                   : "\r\n"));
 115                 }
 116
 117                 send_reply(S_data_sk, AuxBuf);
 118
 119         } while (1);
 120         closedir(dir);
 121
 122 finish:
 123         send_reply(S_cmd_sk, "226 Directory list sent.\r\n");
 124         close(S_data_sk);
 125         S_data_sk      = -1;
 126         S_passive_mode = 0;
 127 }
 128