release/src/router/vsftpd/ls.c

   1 /*
   2  * Part of Very Secure FTPd
   3  * Licence: GPL v2
   4  * Author: Chris Evans
   5  * ls.c
   6  *
   7  * Would you believe, code to handle directory listing.
   8  */
   9
  10 #include "ls.h"
  11 #include "access.h"
  12 #include "defs.h"
  13 #include "str.h"
  14 #include "strlist.h"
  15 #include "sysstr.h"
  16 #include "sysutil.h"
  17 #include "tunables.h"
  18
  19 static void build_dir_line(struct mystr* p_str,
  20                            const struct mystr* p_filename_str,
  21                            const struct vsf_sysutil_statbuf* p_stat,
  22                            long curr_time);
  23
  24 void
  25 vsf_ls_populate_dir_list(struct mystr_list* p_list,
  26                          struct mystr_list* p_subdir_list,
  27                          struct vsf_sysutil_dir* p_dir,
  28                          const struct mystr* p_base_dir_str,
  29                          const struct mystr* p_option_str,
  30                          const struct mystr* p_filter_str,
  31                          int is_verbose)
  32 {
  33   struct mystr dirline_str = INIT_MYSTR;
  34   struct mystr normalised_base_dir_str = INIT_MYSTR;
  35   struct str_locate_result loc_result;
  36   int a_option;
  37   int r_option;
  38   int t_option;
  39   int F_option;
  40   int do_stat = 0;
  41   long curr_time = 0;
  42   loc_result = str_locate_char(p_option_str, 'a');
  43   a_option = loc_result.found;
  44   loc_result = str_locate_char(p_option_str, 'r');
  45   r_option = loc_result.found;
  46   loc_result = str_locate_char(p_option_str, 't');
  47   t_option = loc_result.found;
  48   loc_result = str_locate_char(p_option_str, 'F');
  49   F_option = loc_result.found;
  50   loc_result = str_locate_char(p_option_str, 'l');
  51   if (loc_result.found)
  52   {
  53     is_verbose = 1;
  54   }
  55   /* Invert "reverse" arg for "-t", the time sorting */
  56   if (t_option)
  57   {
  58     r_option = !r_option;
  59   }
  60   if (is_verbose || t_option || F_option || p_subdir_list != 0)
  61   {
  62     do_stat = 1;
  63   }
  64   /* If the filter starts with a . then implicitly enable -a */
  65   if (!str_isempty(p_filter_str) && str_get_char_at(p_filter_str, 0) == '.')
  66   {
  67     a_option = 1;
  68   }
  69   /* "Normalise" the incoming base directory string by making sure it
  70    * ends in a '/' if it is nonempty
  71    */
  72   if (!str_equal_text(p_base_dir_str, "."))
  73   {
  74     str_copy(&normalised_base_dir_str, p_base_dir_str);
  75   }
  76   if (!str_isempty(&normalised_base_dir_str))
  77   {
  78     unsigned int len = str_getlen(&normalised_base_dir_str);
  79     if (str_get_char_at(&normalised_base_dir_str, len - 1) != '/')
  80     {
  81       str_append_char(&normalised_base_dir_str, '/');
  82     }
  83   }
  84   /* If we're going to need to do time comparisions, cache the local time */
  85   if (is_verbose)
  86   {
  87     curr_time = vsf_sysutil_get_time_sec();
  88   }
  89   while (1)
  90   {
  91     int len;
  92     static struct mystr s_next_filename_str;
  93     static struct mystr s_next_path_and_filename_str;
  94     static struct vsf_sysutil_statbuf* s_p_statbuf;
  95     str_next_dirent(&s_next_filename_str, p_dir);
  96     if (str_isempty(&s_next_filename_str))
  97     {
  98       break;
  99     }
 100     len = str_getlen(&s_next_filename_str);
 101     if (len > 0 && str_get_char_at(&s_next_filename_str, 0) == '.')
 102     {
 103       if (!a_option && !tunable_force_dot_files)
 104       {
 105         continue;
 106       }
 107       if (!a_option &&
 108           ((len == 2 && str_get_char_at(&s_next_filename_str, 1) == '.') ||
 109            len == 1))
 110       {
 111         continue;
 112       }
 113     }
 114     /* Don't show hidden directory entries */
 115     if (!vsf_access_check_file_visible(&s_next_filename_str))
 116     {
 117       continue;
 118     }
 119     /* If we have an ls option which is a filter, apply it */
 120     if (!str_isempty(p_filter_str))
 121     {
 122       unsigned int iters = 0;
 123       if (!vsf_filename_passes_filter(&s_next_filename_str, p_filter_str,
 124                                       &iters))
 125       {
 126         continue;
 127       }
 128     }
 129     /* Calculate the full path (relative to CWD) for lstat() and
 130      * output purposes
 131      */
 132     str_copy(&s_next_path_and_filename_str, &normalised_base_dir_str);
 133     str_append_str(&s_next_path_and_filename_str, &s_next_filename_str);
 134     if (do_stat)
 135     {
 136       /* lstat() the file. Of course there's a race condition - the
 137        * directory entry may have gone away whilst we read it, so
 138        * ignore failure to stat
 139        */
 140       int retval = str_lstat(&s_next_path_and_filename_str, &s_p_statbuf);
 141       if (vsf_sysutil_retval_is_error(retval))
 142       {
 143         continue;
 144       }
 145     }
 146     if (is_verbose)
 147     {
 148       static struct mystr s_final_file_str;
 149       /* If it's a damn symlink, we need to append the target */
 150       str_copy(&s_final_file_str, &s_next_filename_str);
 151       if (vsf_sysutil_statbuf_is_symlink(s_p_statbuf))
 152       {
 153         static struct mystr s_temp_str;
 154         int retval = str_readlink(&s_temp_str, &s_next_path_and_filename_str);
 155         if (retval == 0 && !str_isempty(&s_temp_str))
 156         {
 157           str_append_text(&s_final_file_str, " -> ");
 158           str_append_str(&s_final_file_str, &s_temp_str);
 159         }
 160       }
 161       if (F_option && vsf_sysutil_statbuf_is_dir(s_p_statbuf))
 162       {
 163         str_append_char(&s_final_file_str, '/');
 164       }
 165       build_dir_line(&dirline_str, &s_final_file_str, s_p_statbuf, curr_time);
 166     }
 167     else
 168     {
 169       /* Just emit the filenames - note, we prepend the directory for NLST
 170        * but not for LIST
 171        */
 172       str_copy(&dirline_str, &s_next_path_and_filename_str);
 173       if (F_option)
 174       {
 175         if (vsf_sysutil_statbuf_is_dir(s_p_statbuf))
 176         {
 177           str_append_char(&dirline_str, '/');
 178         }
 179         else if (vsf_sysutil_statbuf_is_symlink(s_p_statbuf))
 180         {
 181           str_append_char(&dirline_str, '@');
 182         }
 183       }
 184       str_append_text(&dirline_str, "\r\n");
 185     }
 186     /* Add filename into our sorted list - sorting by filename or time. Also,
 187      * if we are required to, maintain a distinct list of direct
 188      * subdirectories.
 189      */
 190     {
 191       static struct mystr s_temp_str;
 192       const struct mystr* p_sort_str = 0;
 193       const struct mystr* p_sort_subdir_str = 0;
 194       if (!t_option)
 195       {
 196         p_sort_str = &s_next_filename_str;
 197       }
 198       else
 199       {
 200         str_alloc_text(&s_temp_str,
 201                        vsf_sysutil_statbuf_get_sortkey_mtime(s_p_statbuf));
 202         p_sort_str = &s_temp_str;
 203         p_sort_subdir_str = &s_temp_str;
 204       }
 205       str_list_add(p_list, &dirline_str, p_sort_str);
 206       if (p_subdir_list != 0 && vsf_sysutil_statbuf_is_dir(s_p_statbuf))
 207       {
 208         str_list_add(p_subdir_list, &s_next_filename_str, p_sort_subdir_str);
 209       }
 210     }
 211   } /* END: while(1) */
 212   str_list_sort(p_list, r_option);
 213   if (p_subdir_list != 0)
 214   {
 215     str_list_sort(p_subdir_list, r_option);
 216   }
 217   str_free(&dirline_str);
 218   str_free(&normalised_base_dir_str);
 219 }
 220
 221 int
 222 vsf_filename_passes_filter(const struct mystr* p_filename_str,
 223                            const struct mystr* p_filter_str,
 224                            unsigned int* iters)
 225 {
 226   /* A simple routine to match a filename against a pattern.
 227    * This routine is used instead of e.g. fnmatch(3), because we should be
 228    * reluctant to trust the latter. fnmatch(3) involves _lots_ of string
 229    * parsing and handling. There is broad potential for any given fnmatch(3)
 230    * implementation to be buggy.
 231    *
 232    * Currently supported pattern(s):
 233    * - any number of wildcards, "*" or "?"
 234    * - {,} syntax (not nested)
 235    *
 236    * Note that pattern matching is only supported within the last path
 237    * component. For example, searching for /a/b/? will work, but searching
 238    * for /a/?/c will not.
 239    */
 240   struct mystr filter_remain_str = INIT_MYSTR;
 241   struct mystr name_remain_str = INIT_MYSTR;
 242   struct mystr temp_str = INIT_MYSTR;
 243   struct mystr brace_list_str = INIT_MYSTR;
 244   struct mystr new_filter_str = INIT_MYSTR;
 245   int ret = 0;
 246   char last_token = 0;
 247   int must_match_at_current_pos = 1;
 248   str_copy(&filter_remain_str, p_filter_str);
 249   str_copy(&name_remain_str, p_filename_str);
 250
 251   while (!str_isempty(&filter_remain_str) && *iters < VSFTP_MATCHITERS_MAX)
 252   {
 253     static struct mystr s_match_needed_str;
 254     /* Locate next special token */
 255     struct str_locate_result locate_result =
 256       str_locate_chars(&filter_remain_str, "*?{");
 257     (*iters)++;
 258     /* Isolate text leading up to token (if any) - needs to be matched */
 259     if (locate_result.found)
 260     {
 261       unsigned int indexx = locate_result.index;
 262       str_left(&filter_remain_str, &s_match_needed_str, indexx);
 263       str_mid_to_end(&filter_remain_str, &temp_str, indexx + 1);
 264       str_copy(&filter_remain_str, &temp_str);
 265       last_token = locate_result.char_found;
 266     }
 267     else
 268     {
 269       /* No more tokens. Must match remaining filter string exactly. */
 270       str_copy(&s_match_needed_str, &filter_remain_str);
 271       str_empty(&filter_remain_str);
 272       last_token = 0;
 273     }
 274     if (!str_isempty(&s_match_needed_str))
 275     {
 276       /* Need to match something.. could be a match which has to start at
 277        * current position, or we could allow it to start anywhere
 278        */
 279       unsigned int indexx;
 280       locate_result = str_locate_str(&name_remain_str, &s_match_needed_str);
 281       if (!locate_result.found)
 282       {
 283         /* Fail */
 284         goto out;
 285       }
 286       indexx = locate_result.index;
 287       if (must_match_at_current_pos && indexx > 0)
 288       {
 289         goto out;
 290       }
 291       /* Chop matched string out of remainder */
 292       str_mid_to_end(&name_remain_str, &temp_str,
 293                      indexx + str_getlen(&s_match_needed_str));
 294       str_copy(&name_remain_str, &temp_str);
 295     }
 296     if (last_token == '?')
 297     {
 298       if (str_isempty(&name_remain_str))
 299       {
 300         goto out;
 301       }
 302       str_right(&name_remain_str, &temp_str, str_getlen(&name_remain_str) - 1);
 303       str_copy(&name_remain_str, &temp_str);
 304       must_match_at_current_pos = 1;
 305     }
 306     else if (last_token == '{')
 307     {
 308       struct str_locate_result end_brace =
 309         str_locate_char(&filter_remain_str, '}');
 310       must_match_at_current_pos = 1;
 311       if (end_brace.found)
 312       {
 313         str_split_char(&filter_remain_str, &temp_str, '}');
 314         str_copy(&brace_list_str, &filter_remain_str);
 315         str_copy(&filter_remain_str, &temp_str);
 316         str_split_char(&brace_list_str, &temp_str, ',');
 317         while (!str_isempty(&brace_list_str))
 318         {
 319           str_copy(&new_filter_str, &brace_list_str);
 320           str_append_str(&new_filter_str, &filter_remain_str);
 321           if (vsf_filename_passes_filter(&name_remain_str, &new_filter_str,
 322                                          iters))
 323           {
 324             ret = 1;
 325             goto out;
 326           }
 327           str_copy(&brace_list_str, &temp_str);
 328           str_split_char(&brace_list_str, &temp_str, ',');
 329         }
 330         goto out;
 331       }
 332       else if (str_isempty(&name_remain_str) ||
 333                str_get_char_at(&name_remain_str, 0) != '{')
 334       {
 335         goto out;
 336       }
 337       else
 338       {
 339         str_right(&name_remain_str, &temp_str,
 340                   str_getlen(&name_remain_str) - 1);
 341         str_copy(&name_remain_str, &temp_str);
 342       }
 343     }
 344     else
 345     {
 346       must_match_at_current_pos = 0;
 347     }
 348   }
 349   /* Any incoming string left means no match unless we ended on the correct
 350    * type of wildcard.
 351    */
 352   if (str_getlen(&name_remain_str) > 0 && last_token != '*')
 353   {
 354     goto out;
 355   }
 356   /* OK, a match */
 357   ret = 1;
 358   if (*iters == VSFTP_MATCHITERS_MAX) {
 359     ret = 0;
 360   }
 361 out:
 362   str_free(&filter_remain_str);
 363   str_free(&name_remain_str);
 364   str_free(&temp_str);
 365   str_free(&brace_list_str);
 366   str_free(&new_filter_str);
 367   return ret;
 368 }
 369
 370 static void
 371 build_dir_line(struct mystr* p_str, const struct mystr* p_filename_str,
 372                const struct vsf_sysutil_statbuf* p_stat, long curr_time)
 373 {
 374   static struct mystr s_tmp_str;
 375   filesize_t size = vsf_sysutil_statbuf_get_size(p_stat);
 376   /* Permissions */
 377   str_alloc_text(p_str, vsf_sysutil_statbuf_get_perms(p_stat));
 378   str_append_char(p_str, ' ');
 379   /* Hard link count */
 380   str_alloc_ulong(&s_tmp_str, vsf_sysutil_statbuf_get_links(p_stat));
 381   str_lpad(&s_tmp_str, 4);
 382   str_append_str(p_str, &s_tmp_str);
 383   str_append_char(p_str, ' ');
 384   /* User */
 385   if (tunable_hide_ids)
 386   {
 387     str_alloc_text(&s_tmp_str, "ftp");
 388   }
 389   else
 390   {
 391     int uid = vsf_sysutil_statbuf_get_uid(p_stat);
 392     struct vsf_sysutil_user* p_user = 0;
 393     if (tunable_text_userdb_names)
 394     {
 395       p_user = vsf_sysutil_getpwuid(uid);
 396     }
 397     if (p_user == 0)
 398     {
 399       str_alloc_ulong(&s_tmp_str, (unsigned long) uid);
 400     }
 401     else
 402     {
 403       str_alloc_text(&s_tmp_str, vsf_sysutil_user_getname(p_user));
 404     }
 405   }
 406   str_rpad(&s_tmp_str, 8);
 407   str_append_str(p_str, &s_tmp_str);
 408   str_append_char(p_str, ' ');
 409   /* Group */
 410   if (tunable_hide_ids)
 411   {
 412     str_alloc_text(&s_tmp_str, "ftp");
 413   }
 414   else
 415   {
 416     int gid = vsf_sysutil_statbuf_get_gid(p_stat);
 417     struct vsf_sysutil_group* p_group = 0;
 418     if (tunable_text_userdb_names)
 419     {
 420       p_group = vsf_sysutil_getgrgid(gid);
 421     }
 422     if (p_group == 0)
 423     {
 424       str_alloc_ulong(&s_tmp_str, (unsigned long) gid);
 425     }
 426     else
 427     {
 428       str_alloc_text(&s_tmp_str, vsf_sysutil_group_getname(p_group));
 429     }
 430   }
 431   str_rpad(&s_tmp_str, 8);
 432   str_append_str(p_str, &s_tmp_str);
 433   str_append_char(p_str, ' ');
 434   /* Size in bytes */
 435   str_alloc_filesize_t(&s_tmp_str, size);
 436   str_lpad(&s_tmp_str, 8);
 437   str_append_str(p_str, &s_tmp_str);
 438   str_append_char(p_str, ' ');
 439   /* Date stamp */
 440   str_append_text(p_str, vsf_sysutil_statbuf_get_date(p_stat,
 441                                                       tunable_use_localtime,
 442                                                       curr_time));
 443   str_append_char(p_str, ' ');
 444   /* Filename */
 445   str_append_str(p_str, p_filename_str);
 446   str_append_text(p_str, "\r\n");
 447 }
 448