list_dir.c

   1 /*
   2  * User FTP Server,  Share folders over FTP without being root.
   3  * Copyright (C) 2008  Isaac Jurado
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License as published by the Free Software
   7  * Foundation; either version 2 of the License, or (at your option) any later
   8  * version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  12  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  13  * details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  18  */
  19 #include "uftps.h"
  20
  21 /*
  22  * LIST and NLST commands implementation.
  23  *
  24  * To make Mozilla Firefox list the directory contents correctly, some research
  25  * work had to be done.  That concluded in:
  26  *
  27  *     http://cr.yp.to/ftp.html
  28  *
  29  * In particular:
  30  *
  31  *     http://cr.yp.to/ftp/list/binls.html
  32  *
  33  * Only files or subdirectories are shown, the rest of items (symlinks, named
  34  * pipes, sockets...) are ignored.  The following line is sent when a file is
  35  * found:
  36  *
  37  * -rw-r--r-- 1 ftp ftp       999 Mon  88 7777 filename
  38  *
  39  * In case of a subdirectory, the line is:
  40  *
  41  * drwxr-xr-x 1 ftp ftp       999 Mon  88 7777 dirname
  42  *
  43  * Where '999' is the item size, 'Mon  88 7777' is the month, day and year,
  44  * respectively, of the last modification date.  Some servers display the hour
  45  * and minute when the distance between current time and last modification time
  46  * is less than six months.  We don't do that as it is considered irrelevant.
  47  * To obtain a more precise value for the last modification time, let the client
  48  * send a MDTM command.
  49  *
  50  * Note that when, for some reason, directory listing is not possible, an empty
  51  * list is sent.  So this error is not detected from the client, until it tries
  52  * to execute CWD.
  53  *
  54  * Also note that most clients will appreciate listings where all its items are
  55  * stat()-able.
  56  */
  57
  58 #include <sys/types.h>
  59 #include <sys/stat.h>
  60 #include <sys/socket.h>
  61 #include <netinet/in.h>
  62 #include <unistd.h>
  63 #include <dirent.h>
  64 #include <time.h>
  65 #include <string.h>
  66 #include <stdio.h>
  67
  68
  69 /* Month names */
  70 static char month[12][4] = {
  71         "Jan\0", "Feb\0", "Mar\0", "Apr\0", "May\0", "Jun\0", "Jul\0", "Aug\0",
  72         "Sep\0", "Oct\0", "Nov\0", "Dec\0"
  73 };
  74
  75
  76 /*
  77  * Temporary workaround
  78  */
  79 static void send_data (int sk, const char *str, int len)
  80 {
  81         int  b;
  82
  83         do {
  84                 b = write(sk, str, len);
  85                 if (b <= 0)
  86                         return;
  87
  88                 str += b;
  89                 len -= b;
  90         } while (len > 0);
  91 }
  92
  93
  94 void list_dir (int full_list)
  95 {
  96         int                len, l, err;
  97         DIR               *dir;
  98         struct dirent     *dentry;
  99         struct sockaddr_in saddr;
 100         struct stat        st;
 101         struct tm          t;
 102         socklen_t          saddr_len = sizeof(saddr);
 103         char               item[512];
 104
 105         if (SS.passive_mode)
 106                 SS.data_sk = accept(SS.passive_bind_sk,
 107                                    (struct sockaddr *) &saddr, &saddr_len);
 108
 109         /* Workaround for Konqueror and Nautilus */
 110         if (SS.arg != NULL && SS.arg[0] == '-')
 111                 SS.arg = NULL;
 112
 113         len = expand_arg();
 114         dir = opendir(SS.arg);
 115         if (len > 3)
 116         {
 117                 SS.arg[len - 1] = '/';
 118                 len++;
 119         }
 120
 121         reply_c("150 Sending directory list.\r\n");
 122         if (dir == NULL)
 123                 goto finish;
 124
 125         do {
 126                 dentry = readdir(dir);
 127                 if (dentry == NULL)
 128                         break;
 129
 130                 strcpy(&SS.arg[len - 1], dentry->d_name);
 131                 debug("Stating '%s'", SS.arg);
 132                 err = stat(SS.arg, &st);
 133                 if (err == -1)
 134                         continue;
 135
 136                 if (full_list)
 137                 {
 138                         /* LIST */
 139                         gmtime_r(&(st.st_mtime), &t);
 140                         l = snprintf(item, 512,
 141                                      "%s 1 ftp ftp %13lld %s %3d %4d %s\r\n",
 142                                      (S_ISDIR(st.st_mode) ? "dr-xr-xr-x"
 143                                       : "-r--r--r--"), (long long) st.st_size,
 144                                      month[t.tm_mon], t.tm_mday, t.tm_year + 1900,
 145                                      dentry->d_name);
 146                 }
 147                 else
 148                 {
 149                         /* NLST */
 150                         l = snprintf(item, 512, "%s%s", dentry->d_name,
 151                                      (dentry->d_type == DT_DIR ? "/\r\n"
 152                                       : "\r\n"));
 153                 }
 154
 155                 send_data(SS.data_sk, item, l);
 156
 157         } while (1);
 158         closedir(dir);
 159
 160 finish:
 161         reply_c("226 Directory list sent.\r\n");
 162         close(SS.data_sk);
 163         SS.data_sk      = -1;
 164         SS.passive_mode = 0;
 165 }
 166