alpine/osdep/fltrname.c

   1 #if !defined(lint) && !defined(DOS)
   2 static char rcsid[] = "$Id: fltrname.c 769 2007-10-24 00:15:40Z hubert@u.washington.edu $";
   3 #endif
   4
   5 /*
   6  * ========================================================================
   7  * Copyright 2006-2007 University of Washington
   8  * Copyright 2013-2014 Eduardo Chappa
   9  *
  10  * Licensed under the Apache License, Version 2.0 (the "License");
  11  * you may not use this file except in compliance with the License.
  12  * You may obtain a copy of the License at
  13  *
  14  *     http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  * ========================================================================
  17  */
  18
  19 #include "../c-client/mail.h"   /* for MAILSTREAM */
  20 #undef ERROR
  21
  22 #include <system.h>
  23 #include <general.h>
  24
  25 #include "../../pith/osdep/writ_dir.h"
  26 #include "../../pith/osdep/bldpath.h"
  27
  28 #include "fltrname.h"
  29
  30
  31 /*----------------------------------------------------------------------
  32     Filter file names for strange characters
  33
  34    Args:  file  -- the file name to check
  35
  36  Result: Returns NULL if file name is OK
  37          Returns formatted error message if it is not
  38   ----*/
  39 char *
  40 filter_filename(char *file, int *fatal, int strict)
  41 {
  42 #define ALLOW_WEIRD 1
  43 #ifdef ALLOW_WEIRD
  44     static char illegal[] = {'\177', '\0'};
  45 #else
  46 #ifdef  _WINDOWS
  47     static char illegal[] = {'"', '#', '$', '%', '&', /*'/',*/ '(', ')','*',
  48                           ',', ';', '<', '=', '>', '?', '[', ']',
  49                           '^', '|', '\177', '\0'};
  50 #else   /* UNIX */
  51     static char illegal[] = {'"', '#', '$', '%', '&', '\'','(', ')','*',
  52                           ',', ':', ';', '<', '=', '>', '?', '[', ']',
  53                           '\\', '^', '|', '\177', '\0'};
  54 #endif  /* UNIX */
  55 #endif
  56     static char error[100];
  57     char ill_file[MAXPATH+1], *ill_char, *ptr, e2[20];
  58     int i;
  59
  60     for(ptr = file; *ptr == ' '; ptr++) ; /* leading spaces gone */
  61
  62     while(*ptr && (unsigned char)(*ptr) >= ' ' && strchr(illegal, *ptr) == 0)
  63       ptr++;
  64
  65     *fatal = TRUE;
  66     if(*ptr != '\0') {
  67         if(*ptr == '\n') {
  68             ill_char = "<newline>";
  69         } else if(*ptr == '\r') {
  70             ill_char = "<carriage return>";
  71         } else if(*ptr == '\t') {
  72             ill_char = "<tab>";
  73             *fatal = FALSE;             /* just whitespace */
  74         } else if(*ptr < ' ') {
  75             snprintf(e2, sizeof(e2), "control-%c", *ptr + '@');
  76             ill_char = e2;
  77         } else if (*ptr == '\177') {
  78             ill_char = "<del>";
  79         } else {
  80             e2[0] = *ptr;
  81             e2[1] = '\0';
  82             ill_char = e2;
  83             *fatal = FALSE;             /* less offensive? */
  84         }
  85         if(!*fatal){
  86             strncpy(error, ill_char, sizeof(error)-1);
  87             error[sizeof(error)-1] = '\0';
  88         }
  89         else if(ptr != file) {
  90             strncpy(ill_file, file, MIN(ptr-file,sizeof(ill_file)-1));
  91             ill_file[MIN(ptr-file,sizeof(ill_file)-1)] = '\0';
  92             snprintf(error, sizeof(error),
  93                     "Character \"%s\" after \"%.*s\" not allowed in file name",
  94                     ill_char, sizeof(error)-50, ill_file);
  95         } else {
  96             snprintf(error, sizeof(error),
  97                     "First character, \"%s\", not allowed in file name",
  98                     ill_char);
  99         }
 100
 101         return(error);
 102     }
 103
 104     if((i=is_writable_dir(file)) == 0 || i == 1){
 105         snprintf(error, sizeof(error), "\"%.*s\" is a directory", sizeof(error)-50, file);
 106         return(error);
 107     }
 108
 109     if(strict){
 110         for(ptr = file; *ptr == ' '; ptr++) ;   /* leading spaces gone */
 111
 112         if((ptr[0] == '.' && ptr[1] == '.') || filename_parent_ref(ptr)){
 113             snprintf(error, sizeof(error), "\"..\" not allowed in filename");
 114             return(error);
 115         }
 116     }
 117
 118     return((char *)NULL);
 119 }