dist/ipf/lib/getport.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2002-2005 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * Id: getport.c,v 1.1.4.6 2006/06/16 17:21:00 darrenr Exp
   9  */
  10
  11 #include "ipf.h"
  12
  13 int getport(fr, name, port)
  14 frentry_t *fr;
  15 char *name;
  16 u_short *port;
  17 {
  18         struct protoent *p;
  19         struct servent *s;
  20         u_short p1;
  21
  22         if (fr == NULL || fr->fr_type != FR_T_IPF) {
  23                 s = getservbyname(name, NULL);
  24                 if (s != NULL) {
  25                         *port = s->s_port;
  26                         return 0;
  27                 }
  28                 return -1;
  29         }
  30
  31         /*
  32          * Some people will use port names in rules without specifying
  33          * either TCP or UDP because it is implied by the group head.
  34          * If we don't know the protocol, then the best we can do here is
  35          * to take either only the TCP or UDP mapping (if one or the other
  36          * is missing) or make sure both of them agree.
  37          */
  38         if (fr->fr_proto == 0) {
  39                 s = getservbyname(name, "tcp");
  40                 if (s != NULL)
  41                         p1 = s->s_port;
  42                 else
  43                         p1 = 0;
  44                 s = getservbyname(name, "udp");
  45                 if (s != NULL) {
  46                         if (p1 != s->s_port)
  47                                 return -1;
  48                 }
  49                 if ((p1 == 0) && (s == NULL))
  50                         return -1;
  51                 if (p1)
  52                         *port = p1;
  53                 else
  54                         *port = s->s_port;
  55                 return 0;
  56         }
  57
  58         if ((fr->fr_flx & FI_TCPUDP) != 0) {
  59                 /*
  60                  * If a rule is "tcp/udp" then check that both TCP and UDP
  61                  * mappings for this protocol name match ports.
  62                  */
  63                 s = getservbyname(name, "tcp");
  64                 if (s == NULL)
  65                         return -1;
  66                 p1 = s->s_port;
  67                 s = getservbyname(name, "udp");
  68                 if (s == NULL || s->s_port != p1)
  69                         return -1;
  70                 *port = p1;
  71                 return 0;
  72         }
  73
  74         p = getprotobynumber(fr->fr_proto);
  75         s = getservbyname(name, p ? p->p_name : NULL);
  76         if (s != NULL) {
  77                 *port = s->s_port;
  78                 return 0;
  79         }
  80         return -1;
  81 }