access.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1998
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 /*
  20   hosts allow/deny code for rsync
  21
  22   */
  23
  24 #include "rsync.h"
  25
  26
  27 static int match_hostname(char *host, char *tok)
  28 {
  29         if (!host || !*host) return 0;
  30         return (fnmatch(tok, host, 0) == 0);
  31 }
  32
  33
  34 static int match_address(char *addr, char *tok)
  35 {
  36         char *p;
  37         unsigned long a, t, mask = (unsigned long)~0;
  38
  39         if (!addr || !*addr) return 0;
  40
  41         if (!isdigit(tok[0])) return 0;
  42
  43         p = strchr(tok,'/');
  44         if (p) *p = 0;
  45
  46         a = inet_addr(addr);
  47         t = inet_addr(tok);
  48
  49         if (p) {
  50                 *p = '/';
  51         }
  52
  53         if (t == INADDR_NONE) {
  54                 rprintf(FERROR,"malformed address %s\n", tok);
  55                 return 0;
  56         }
  57
  58         a = ntohl(a);
  59         t = ntohl(t);
  60
  61         if (p) {
  62                 if (strchr(p+1,'.')) {
  63                         mask = inet_addr(p+1);
  64                         if (mask == INADDR_NONE) {
  65                                 rprintf(FERROR,"malformed mask in %s\n", tok);
  66                                 return 0;
  67                         }
  68                         mask = ntohl(mask);
  69                 } else {
  70                         int bits = atoi(p+1);
  71                         if (bits == 0) return 1;
  72                         if (bits <= 0 || bits > 32) {
  73                                 rprintf(FERROR,"malformed mask in %s\n", tok);
  74                                 return 0;
  75                         }
  76                         mask &= (mask << (32-bits));
  77                 }
  78         }
  79
  80         return ((a&mask) == (t&mask));
  81 }
  82
  83 static int access_match(char *list, char *addr, char *host)
  84 {
  85         char *tok;
  86         char *list2 = strdup(list);
  87
  88         if (!list2) out_of_memory("access_match");
  89
  90         strlower(list2);
  91         if (host) strlower(host);
  92
  93         for (tok=strtok(list2," ,\t"); tok; tok=strtok(NULL," ,\t")) {
  94                 if (match_hostname(host, tok) || match_address(addr, tok)) {
  95                         free(list2);
  96                         return 1;
  97                 }
  98         }
  99
 100         free(list2);
 101         return 0;
 102 }
 103
 104 int allow_access(char *addr, char *host, char *allow_list, char *deny_list)
 105 {
 106         /* if theres no deny list and no allow list then allow access */
 107         if ((!deny_list || !*deny_list) && (!allow_list || !*allow_list))
 108                 return 1;
 109
 110         /* if there is an allow list but no deny list then allow only hosts
 111            on the allow list */
 112         if (!deny_list || !*deny_list)
 113                 return(access_match(allow_list, addr, host));
 114
 115         /* if theres a deny list but no allow list then allow
 116            all hosts not on the deny list */
 117         if (!allow_list || !*allow_list)
 118                 return(!access_match(deny_list,addr,host));
 119
 120         /* if there are both type of list then allow all hosts on the
 121            allow list */
 122         if (access_match(allow_list,addr,host))
 123                 return 1;
 124
 125         /* if there are both type of list and it's not on the allow then
 126            allow it if its not on the deny */
 127         if (access_match(deny_list,addr,host))
 128                 return 0;
 129
 130         return 1;
 131 }