external/ibm-public/postfix/dist/src/util/sock_addr.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      sock_addr 3
   6 /* SUMMARY
   7 /*      sockaddr utilities
   8 /* SYNOPSIS
   9 /*      #include <sock_addr.h>
  10 /*
  11 /*      int     sock_addr_cmp_addr(sa, sb)
  12 /*      const struct sockaddr *sa;
  13 /*      const struct sockaddr *sb;
  14 /*
  15 /*      int     sock_addr_cmp_port(sa, sb)
  16 /*      const struct sockaddr *sa;
  17 /*      const struct sockaddr *sb;
  18 /*
  19 /*      int     SOCK_ADDR_EQ_ADDR(sa, sb)
  20 /*      const struct sockaddr *sa;
  21 /*      const struct sockaddr *sb;
  22 /*
  23 /*      int     SOCK_ADDR_EQ_PORT(sa, sb)
  24 /*      const struct sockaddr *sa;
  25 /*      const struct sockaddr *sb;
  26 /*
  27 /*      int     sock_addr_in_loopback(sa)
  28 /*      const struct sockaddr *sa;
  29 /* AUXILIARY MACROS
  30 /*      struct sockaddr *SOCK_ADDR_PTR(ptr)
  31 /*      unsigned char SOCK_ADDR_FAMILY(ptr)
  32 /*      unsigned char SOCK_ADDR_LEN(ptr)
  33 /*      unsigned short SOCK_ADDR_PORT(ptr)
  34 /*      unsigned short *SOCK_ADDR_PORTP(ptr)
  35 /*
  36 /*      struct sockaddr_in *SOCK_ADDR_IN_PTR(ptr)
  37 /*      unsigned char SOCK_ADDR_IN_FAMILY(ptr)
  38 /*      unsigned short SOCK_ADDR_IN_PORT(ptr)
  39 /*      struct in_addr SOCK_ADDR_IN_ADDR(ptr)
  40 /*      struct in_addr IN_ADDR(ptr)
  41 /*
  42 /*      struct sockaddr_in6 *SOCK_ADDR_IN6_PTR(ptr)
  43 /*      unsigned char SOCK_ADDR_IN6_FAMILY(ptr)
  44 /*      unsigned short SOCK_ADDR_IN6_PORT(ptr)
  45 /*      struct in6_addr SOCK_ADDR_IN6_ADDR(ptr)
  46 /*      struct in6_addr IN6_ADDR(ptr)
  47 /* DESCRIPTION
  48 /*      These utilities take protocol-independent address structures
  49 /*      and perform protocol-dependent operations on structure members.
  50 /*      Some of the macros described here are called unsafe,
  51 /*      because they evaluate one or more arguments multiple times.
  52 /*
  53 /*      sock_addr_cmp_addr() or sock_addr_cmp_port() compare the
  54 /*      address family and network address or port fields for
  55 /*      equality, and return indication of the difference between
  56 /*      their arguments:  < 0 if the first argument is "smaller",
  57 /*      0 for equality, and > 0 if the first argument is "larger".
  58 /*
  59 /*      The unsafe macros SOCK_ADDR_EQ_ADDR() or SOCK_ADDR_EQ_PORT()
  60 /*      compare compare the address family and network address or
  61 /*      port fields for equality, and return non-zero when their
  62 /*      arguments differ.
  63 /*
  64 /*      sock_addr_in_loopback() determines if the argument specifies
  65 /*      a loopback address.
  66 /*
  67 /*      The SOCK_ADDR_PTR() macro casts a generic pointer to (struct
  68 /*      sockaddr *).  The name is upper case for consistency not
  69 /*      safety.  SOCK_ADDR_FAMILY() and SOCK_ADDR_LEN() return the
  70 /*      address family and length of the real structure that hides
  71 /*      inside a generic sockaddr structure. On systems where struct
  72 /*      sockaddr has no sa_len member, SOCK_ADDR_LEN() cannot be
  73 /*      used as lvalue. SOCK_ADDR_PORT() returns the IPv4 or IPv6
  74 /*      port number, in network byte order; it must not be used as
  75 /*      lvalue. SOCK_ADDR_PORTP() returns a pointer to the same.
  76 /*
  77 /*      The macros SOCK_ADDR_IN{,6}_{PTR,FAMILY,PORT,ADDR}() cast
  78 /*      a generic pointer to a specific socket address structure
  79 /*      pointer, or access a specific socket address structure
  80 /*      member. These can be used as lvalues.
  81 /*
  82 /*      The unsafe INADDR() and IN6_ADDR() macros dereference a
  83 /*      generic pointer to a specific address structure.
  84 /* DIAGNOSTICS
  85 /*      Panic: unsupported address family.
  86 /* LICENSE
  87 /* .ad
  88 /* .fi
  89 /*      The Secure Mailer license must be distributed with this software.
  90 /* AUTHOR(S)
  91 /*      Wietse Venema
  92 /*      IBM T.J. Watson Research
  93 /*      P.O. Box 704
  94 /*      Yorktown Heights, NY 10598, USA
  95 /*--*/
  96
  97 /* System library. */
  98
  99 #include <sys_defs.h>
 100 #include <sys/socket.h>
 101 #include <netinet/in.h>
 102 #include <string.h>
 103
 104 /* Utility library. */
 105
 106 #include <msg.h>
 107 #include <sock_addr.h>
 108
 109 /* sock_addr_cmp_addr - compare addresses for equality */
 110
 111 int     sock_addr_cmp_addr(const struct sockaddr * sa,
 112                                    const struct sockaddr * sb)
 113 {
 114     if (sa->sa_family != sb->sa_family)
 115         return (sa->sa_family - sb->sa_family);
 116
 117     /*
 118      * With IPv6 address structures, assume a non-hostile implementation that
 119      * stores the address as a contiguous sequence of bits. Any holes in the
 120      * sequence would invalidate the use of memcmp().
 121      */
 122     if (sa->sa_family == AF_INET) {
 123         return (SOCK_ADDR_IN_ADDR(sa).s_addr - SOCK_ADDR_IN_ADDR(sb).s_addr);
 124 #ifdef HAS_IPV6
 125     } else if (sa->sa_family == AF_INET6) {
 126         return (memcmp((char *) &(SOCK_ADDR_IN6_ADDR(sa)),
 127                        (char *) &(SOCK_ADDR_IN6_ADDR(sb)),
 128                        sizeof(SOCK_ADDR_IN6_ADDR(sa))));
 129 #endif
 130     } else {
 131         msg_panic("sock_addr_cmp_addr: unsupported address family %d",
 132                   sa->sa_family);
 133     }
 134 }
 135
 136 /* sock_addr_cmp_port - compare ports for equality */
 137
 138 int     sock_addr_cmp_port(const struct sockaddr * sa,
 139                                    const struct sockaddr * sb)
 140 {
 141     if (sa->sa_family != sb->sa_family)
 142         return (sa->sa_family - sb->sa_family);
 143
 144     if (sa->sa_family == AF_INET) {
 145         return (SOCK_ADDR_IN_PORT(sa) - SOCK_ADDR_IN_PORT(sb));
 146 #ifdef HAS_IPV6
 147     } else if (sa->sa_family == AF_INET6) {
 148         return (SOCK_ADDR_IN6_PORT(sa) - SOCK_ADDR_IN6_PORT(sb));
 149 #endif
 150     } else {
 151         msg_panic("sock_addr_cmp_port: unsupported address family %d",
 152                   sa->sa_family);
 153     }
 154 }
 155
 156 /* sock_addr_in_loopback - determine if address is loopback */
 157
 158 int sock_addr_in_loopback(const struct sockaddr * sa)
 159 {
 160     unsigned long inaddr;
 161
 162     if (sa->sa_family == AF_INET) {
 163         inaddr = ntohl(SOCK_ADDR_IN_ADDR(sa).s_addr);
 164         return (IN_CLASSA(inaddr)
 165                 && ((inaddr & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT)
 166                 == IN_LOOPBACKNET);
 167 #ifdef HAS_IPV6
 168     } else if (sa->sa_family == AF_INET6) {
 169         return (IN6_IS_ADDR_LOOPBACK(&SOCK_ADDR_IN6_ADDR(sa)));
 170 #endif
 171     } else {
 172         msg_panic("sock_addr_in_loopback: unsupported address family %d",
 173                   sa->sa_family);
 174     }
 175 }