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 static int match_binary(char *b1, char *b2, char *mask, int addrlen)
  34 {
  35         int i;
  36
  37         for (i=0; i<addrlen; i++) {
  38                 if ((b1[i]^b2[i])&mask[i]) {
  39                         return 0;
  40                 }
  41         }
  42
  43         return 1;
  44 }
  45
  46 static void make_mask(char *mask, int plen, int addrlen) {
  47         int w, b;
  48
  49         w = plen >> 3;
  50         b = plen & 0x7;
  51
  52         if (w)
  53                 memset(mask, 0xff, w);
  54         if (w < addrlen)
  55                 mask[w] = 0xff & (0xff<<(8-b));
  56         if (w+1 < addrlen)
  57                 memset(mask+w+1, 0, addrlen-w-1);
  58
  59         return;
  60 }
  61
  62 static int match_address(char *addr, char *tok)
  63 {
  64         char *p;
  65         struct addrinfo hints, *resa, *rest;
  66         int gai;
  67         int ret = 0;
  68         int addrlen = 0;
  69 #ifdef HAVE_STRTOL
  70         long int bits;
  71 #else
  72         int bits;
  73 #endif
  74         char mask[16];
  75         char *a = NULL, *t = NULL;
  76
  77         if (!addr || !*addr) return 0;
  78
  79         p = strchr(tok,'/');
  80         if (p) *p = 0;
  81
  82         /* skip if last char is not a digit (i.e. not an address) */
  83         /* (don't check first char - might be 11.22.33.44.an.isp) */
  84         if (!*tok) return 0;    /* nothing to check */
  85         if (!isdigit(*(unsigned char*)tok+strlen(tok)-1)) return 0;
  86
  87         memset(&hints, 0, sizeof(hints));
  88         hints.ai_family = PF_UNSPEC;
  89         hints.ai_socktype = SOCK_STREAM;
  90 #ifdef AI_NUMERICHOST
  91         hints.ai_flags = AI_NUMERICHOST;
  92 #endif
  93
  94         gai = getaddrinfo(addr, NULL, &hints, &resa);
  95         if (gai) return 0;
  96
  97         gai = getaddrinfo(tok, NULL, &hints, &rest);
  98         if (p)
  99                 *p++ = '/';
 100         if (gai) {
 101                 rprintf(FERROR,"malformed address %s\n", tok);
 102                 freeaddrinfo(resa);
 103                 return 0;
 104         }
 105
 106         if (rest->ai_family != resa->ai_family) {
 107                 ret = 0;
 108                 goto out;
 109         }
 110
 111         switch(resa->ai_family) {
 112         case PF_INET:
 113                 a = (char *)&((struct sockaddr_in *)resa->ai_addr)->sin_addr;
 114                 t = (char *)&((struct sockaddr_in *)rest->ai_addr)->sin_addr;
 115                 addrlen = 4;
 116
 117                 break;
 118
 119 #ifdef INET6
 120         case PF_INET6:
 121             {
 122                 struct sockaddr_in6 *sin6a, *sin6t;
 123
 124                 sin6a = (struct sockaddr_in6 *)resa->ai_addr;
 125                 sin6t = (struct sockaddr_in6 *)rest->ai_addr;
 126
 127                 a = (char *)&sin6a->sin6_addr;
 128                 t = (char *)&sin6t->sin6_addr;
 129
 130                 addrlen = 16;
 131
 132 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
 133                 if (sin6t->sin6_scope_id &&
 134                     sin6a->sin6_scope_id != sin6t->sin6_scope_id) {
 135                         ret = 0;
 136                         goto out;
 137                 }
 138 #endif
 139
 140                 break;
 141             }
 142 #endif
 143         default:
 144             rprintf(FERROR,"unknown family %u\n", rest->ai_family);
 145             ret = 0;
 146             goto out;
 147         }
 148
 149         bits = -1;
 150         if (p) {
 151                 if (inet_pton(resa->ai_addr->sa_family, p, mask) <= 0) {
 152 #ifdef HAVE_STRTOL
 153                         char *ep = NULL;
 154 #else
 155                         unsigned char *pp;
 156 #endif
 157
 158 #ifdef HAVE_STRTOL
 159                         bits = strtol(p, &ep, 10);
 160                         if (!*p || *ep) {
 161                                 rprintf(FERROR,"malformed mask in %s\n", tok);
 162                                 ret = 0;
 163                                 goto out;
 164                         }
 165 #else
 166                         for (pp = (unsigned char *)p; *pp; pp++) {
 167                                 if (!isascii(*pp) || !isdigit(*pp)) {
 168                                         rprintf(FERROR,"malformed mask in %s\n", tok);
 169                                         ret = 0;
 170                                         goto out;
 171                                 }
 172                         }
 173                         bits = atoi(p);
 174 #endif
 175                         if (bits == 0) {
 176                                 ret = 1;
 177                                 goto out;
 178                         }
 179                         if (bits < 0 || bits > (addrlen << 3)) {
 180                                 rprintf(FERROR,"malformed mask in %s\n", tok);
 181                                 ret = 0;
 182                                 goto out;
 183                         }
 184                 }
 185         } else {
 186                 bits = 128;
 187         }
 188
 189         if (bits >= 0)
 190                 make_mask(mask, bits, addrlen);
 191
 192         ret = match_binary(a, t, mask, addrlen);
 193
 194 out:
 195         freeaddrinfo(resa);
 196         freeaddrinfo(rest);
 197         return ret;
 198 }
 199
 200 static int access_match(char *list, char *addr, char *host)
 201 {
 202         char *tok;
 203         char *list2 = strdup(list);
 204
 205         if (!list2) out_of_memory("access_match");
 206
 207         strlower(list2);
 208         if (host) strlower(host);
 209
 210         for (tok=strtok(list2," ,\t"); tok; tok=strtok(NULL," ,\t")) {
 211                 if (match_hostname(host, tok) || match_address(addr, tok)) {
 212                         free(list2);
 213                         return 1;
 214                 }
 215         }
 216
 217         free(list2);
 218         return 0;
 219 }
 220
 221 int allow_access(char *addr, char *host, char *allow_list, char *deny_list)
 222 {
 223         /* if theres no deny list and no allow list then allow access */
 224         if ((!deny_list || !*deny_list) && (!allow_list || !*allow_list))
 225                 return 1;
 226
 227         /* if there is an allow list but no deny list then allow only hosts
 228            on the allow list */
 229         if (!deny_list || !*deny_list)
 230                 return(access_match(allow_list, addr, host));
 231
 232         /* if theres a deny list but no allow list then allow
 233            all hosts not on the deny list */
 234         if (!allow_list || !*allow_list)
 235                 return(!access_match(deny_list,addr,host));
 236
 237         /* if there are both type of list then allow all hosts on the
 238            allow list */
 239         if (access_match(allow_list,addr,host))
 240                 return 1;
 241
 242         /* if there are both type of list and it's not on the allow then
 243            allow it if its not on the deny */
 244         if (access_match(deny_list,addr,host))
 245                 return 0;
 246
 247         return 1;
 248 }