release/src/router/miniupnpd/upnppermissions.c

   1 /* $Id: upnppermissions.c,v 1.17 2012/02/15 22:43:34 nanard Exp $ */
   2 /* MiniUPnP project
   3  * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
   4  * (c) 2006-2012 Thomas Bernard
   5  * This software is subject to the conditions detailed
   6  * in the LICENCE file provided within the distribution */
   7
   8 #include <ctype.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include <syslog.h>
  13 #include <netinet/in.h>
  14 #include <arpa/inet.h>
  15 #include <unistd.h>
  16 #include "config.h"
  17 #include "upnppermissions.h"
  18
  19 /* read_permission_line()
  20  * parse the a permission line which format is :
  21  * (deny|allow) [0-9]+(-[0-9]+) ip/mask [0-9]+(-[0-9]+)
  22  * ip/mask is either 192.168.1.1/24 or 192.168.1.1/255.255.255.0
  23  */
  24 int
  25 read_permission_line(struct upnpperm * perm,
  26                      char * p)
  27 {
  28         char * q;
  29         int n_bits;
  30         int i;
  31
  32         /* first token: (allow|deny) */
  33         while(isspace(*p))
  34                 p++;
  35         if(0 == memcmp(p, "allow", 5))
  36         {
  37                 perm->type = UPNPPERM_ALLOW;
  38                 p += 5;
  39         }
  40         else if(0 == memcmp(p, "deny", 4))
  41         {
  42                 perm->type = UPNPPERM_DENY;
  43                 p += 4;
  44         }
  45         else
  46         {
  47                 return -1;
  48         }
  49         while(isspace(*p))
  50                 p++;
  51
  52         /* second token: eport or eport_min-eport_max */
  53         if(!isdigit(*p))
  54                 return -1;
  55         for(q = p; isdigit(*q); q++);
  56         if(*q=='-')
  57         {
  58                 *q = '\0';
  59                 i = atoi(p);
  60                 if(i > 65535)
  61                         return -1;
  62                 perm->eport_min = (u_short)i;
  63                 q++;
  64                 p = q;
  65                 while(isdigit(*q))
  66                         q++;
  67                 *q = '\0';
  68                 i = atoi(p);
  69                 if(i > 65535)
  70                         return -1;
  71                 perm->eport_max = (u_short)i;
  72                 if(perm->eport_min > perm->eport_max)
  73                         return -1;
  74         }
  75         else if(isspace(*q))
  76         {
  77                 *q = '\0';
  78                 i = atoi(p);
  79                 if(i > 65535)
  80                         return -1;
  81                 perm->eport_min = perm->eport_max = (u_short)i;
  82         }
  83         else
  84         {
  85                 return -1;
  86         }
  87         p = q + 1;
  88         while(isspace(*p))
  89                 p++;
  90
  91         /* third token:  ip/mask */
  92         if(!isdigit(*p))
  93                 return -1;
  94         for(q = p; isdigit(*q) || (*q == '.'); q++);
  95         if(*q=='/')
  96         {
  97                 *q = '\0';
  98                 if(!inet_aton(p, &perm->address))
  99                         return -1;
 100                 q++;
 101                 p = q;
 102                 while(isdigit(*q))
 103                         q++;
 104                 if(*q == '.')
 105                 {
 106                         while(*q == '.' || isdigit(*q))
 107                                 q++;
 108                         if(!isspace(*q))
 109                                 return -1;
 110                         *q = '\0';
 111                         if(!inet_aton(p, &perm->mask))
 112                                 return -1;
 113                 }
 114                 else if(!isspace(*q))
 115                         return -1;
 116                 else
 117                 {
 118                         *q = '\0';
 119                         n_bits = atoi(p);
 120                         if(n_bits > 32)
 121                                 return -1;
 122                         perm->mask.s_addr = htonl(n_bits ? (0xffffffffu << (32 - n_bits)) : 0);
 123                 }
 124         }
 125         else if(isspace(*q))
 126         {
 127                 *q = '\0';
 128                 if(!inet_aton(p, &perm->address))
 129                         return -1;
 130                 perm->mask.s_addr = 0xffffffffu;
 131         }
 132         else
 133         {
 134                 return -1;
 135         }
 136         p = q + 1;
 137
 138         /* fourth token: iport or iport_min-iport_max */
 139         while(isspace(*p))
 140                 p++;
 141         if(!isdigit(*p))
 142                 return -1;
 143         for(q = p; isdigit(*q); q++);
 144         if(*q=='-')
 145         {
 146                 *q = '\0';
 147                 i = atoi(p);
 148                 if(i > 65535)
 149                         return -1;
 150                 perm->iport_min = (u_short)i;
 151                 q++;
 152                 p = q;
 153                 while(isdigit(*q))
 154                         q++;
 155                 *q = '\0';
 156                 i = atoi(p);
 157                 if(i > 65535)
 158                         return -1;
 159                 perm->iport_max = (u_short)i;
 160                 if(perm->iport_min > perm->iport_max)
 161                         return -1;
 162         }
 163         else if(isspace(*q) || *q == '\0')
 164         {
 165                 *q = '\0';
 166                 i = atoi(p);
 167                 if(i > 65535)
 168                         return -1;
 169                 perm->iport_min = perm->iport_max = (u_short)i;
 170         }
 171         else
 172         {
 173                 return -1;
 174         }
 175 #ifdef DEBUG
 176         printf("perm rule added : %s %hu-%hu %08x/%08x %hu-%hu\n",
 177                (perm->type==UPNPPERM_ALLOW)?"allow":"deny",
 178                perm->eport_min, perm->eport_max, ntohl(perm->address.s_addr),
 179                ntohl(perm->mask.s_addr), perm->iport_min, perm->iport_max);
 180 #endif
 181         return 0;
 182 }
 183
 184 #ifdef USE_MINIUPNPDCTL
 185 void
 186 write_permlist(int fd, const struct upnpperm * permary,
 187                int nperms)
 188 {
 189         int l;
 190         const struct upnpperm * perm;
 191         int i;
 192         char buf[128];
 193         write(fd, "Permissions :\n", 14);
 194         for(i = 0; i<nperms; i++)
 195         {
 196                 perm = permary + i;
 197                 l = snprintf(buf, sizeof(buf), "%02d %s %hu-%hu %08x/%08x %hu-%hu\n",
 198                i,
 199            (perm->type==UPNPPERM_ALLOW)?"allow":"deny",
 200                perm->eport_min, perm->eport_max, ntohl(perm->address.s_addr),
 201                ntohl(perm->mask.s_addr), perm->iport_min, perm->iport_max);
 202                 if(l<0)
 203                         return;
 204                 write(fd, buf, l);
 205         }
 206 }
 207 #endif
 208
 209 /* match_permission()
 210  * returns: 1 if eport, address, iport matches the permission rule
 211  *          0 if no match */
 212 static int
 213 match_permission(const struct upnpperm * perm,
 214                  u_short eport, struct in_addr address, u_short iport)
 215 {
 216         if( (eport < perm->eport_min) || (perm->eport_max < eport))
 217                 return 0;
 218         if( (iport < perm->iport_min) || (perm->iport_max < iport))
 219                 return 0;
 220         if( (address.s_addr & perm->mask.s_addr)
 221            != (perm->address.s_addr & perm->mask.s_addr) )
 222                 return 0;
 223         return 1;
 224 }
 225
 226 int
 227 check_upnp_rule_against_permissions(const struct upnpperm * permary,
 228                                     int n_perms,
 229                                     u_short eport, struct in_addr address,
 230                                     u_short iport)
 231 {
 232         int i;
 233         for(i=0; i<n_perms; i++)
 234         {
 235                 if(match_permission(permary + i, eport, address, iport))
 236                 {
 237                         syslog(LOG_DEBUG,
 238                                "UPnP permission rule %d matched : port mapping %s",
 239                                i, (permary[i].type == UPNPPERM_ALLOW)?"accepted":"rejected"
 240                                );
 241                         return (permary[i].type == UPNPPERM_ALLOW);
 242                 }
 243         }
 244         syslog(LOG_DEBUG, "no permission rule matched : accept by default (n_perms=%d)", n_perms);
 245         return 1;       /* Default : accept */
 246 }
 247