usr/src/lib/libwrap/misc.c

   1 /*
   2  * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5 #pragma ident   "%Z%%M% %I%     %E% SMI"
   6
   7  /*
   8   * Misc routines that are used by tcpd and by tcpdchk.
   9   *
  10   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
  11   */
  12
  13 #ifndef lint
  14 static char sccsic[] = "@(#) misc.c 1.2 96/02/11 17:01:29";
  15 #endif
  16
  17 #include <sys/types.h>
  18 #include <sys/param.h>
  19 #include <netinet/in.h>
  20 #include <arpa/inet.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <ctype.h>
  24 #include <netdb.h>
  25
  26 #include "tcpd.h"
  27
  28 extern char *fgets();
  29
  30 #ifndef INADDR_NONE
  31 #define INADDR_NONE     (-1)            /* XXX should be 0xffffffff */
  32 #endif
  33
  34 /* xgets - fgets() with backslash-newline stripping */
  35
  36 char   *xgets(ptr, len, fp)
  37 char   *ptr;
  38 int     len;
  39 FILE   *fp;
  40 {
  41     int     got;
  42     char   *start = ptr;
  43
  44     while (fgets(ptr, len, fp)) {
  45         got = strlen(ptr);
  46         if (got >= 1 && ptr[got - 1] == '\n') {
  47             tcpd_context.line++;
  48             if (got >= 2 && ptr[got - 2] == '\\') {
  49                 got -= 2;
  50             } else {
  51                 return (start);
  52             }
  53         }
  54         ptr += got;
  55         len -= got;
  56         ptr[0] = 0;
  57     }
  58     return (ptr > start ? start : 0);
  59 }
  60
  61 /* split_at - break string at delimiter or return NULL */
  62
  63 char   *split_at(string, delimiter)
  64 char   *string;
  65 int     delimiter;
  66 {
  67     char   *cp;
  68
  69     if ((cp = strchr(string, delimiter)) != 0)
  70         *cp++ = 0;
  71     return (cp);
  72 }
  73
  74 /* dot_quad_addr - convert dotted quad to internal form */
  75
  76 unsigned long dot_quad_addr(str)
  77 char   *str;
  78 {
  79     int     in_run = 0;
  80     int     runs = 0;
  81     char   *cp = str;
  82
  83     /* Count the number of runs of non-dot characters. */
  84
  85     while (*cp) {
  86         if (*cp == '.') {
  87             in_run = 0;
  88         } else if (in_run == 0) {
  89             in_run = 1;
  90             runs++;
  91         }
  92         cp++;
  93     }
  94     return (runs == 4 ? inet_addr(str) : INADDR_NONE);
  95 }
  96
  97 /* numeric_addr - convert textual IP address to binary form */
  98
  99 int numeric_addr(str, addr, af, len)
 100 char *str;
 101 union gen_addr *addr;
 102 int *af;
 103 int *len;
 104 {
 105     union gen_addr t;
 106
 107     if (addr == NULL)
 108         addr = &t;
 109 #ifdef HAVE_IPV6
 110     if (strchr(str,':')) {
 111         if (af) *af = AF_INET6;
 112         if (len) *len = sizeof(struct in6_addr);
 113         if (inet_pton(AF_INET6, str, (void*) addr) == 1)
 114             return 0;
 115         return -1;
 116     }
 117 #endif
 118     if (af) *af = AF_INET;
 119     if (len) *len = sizeof(struct in_addr);
 120     addr->ga_in.s_addr = dot_quad_addr(str);
 121     return addr->ga_in.s_addr == INADDR_NONE ? -1 : 0;
 122 }
 123
 124 /* For none RFC 2553 compliant systems */
 125 #ifdef USE_GETHOSTBYNAME2
 126 #define getipnodebyname(h,af,flags,err) gethostbyname2(h,af)
 127 #define freehostent(x)                  x = 0
 128 #endif
 129
 130 /* tcpd_gethostbyname - an IP family neutral gethostbyname */
 131
 132 struct hostent *tcpd_gethostbyname(host, af)
 133 char *host;
 134 int af;
 135 {
 136 #ifdef HAVE_IPV6
 137     struct hostent *hp;
 138     static struct hostent *hs;          /* freehostent() on next call */
 139     int err;
 140
 141     if (af == AF_INET6) {               /* must be AF_INET6 */
 142         if (hs)
 143             freehostent(hs);
 144         return (hs = getipnodebyname(host, AF_INET6, 0, &err));
 145     }
 146     hp = gethostbyname(host);
 147     if (hp != NULL || af == AF_INET) {  /* found or must be AF_INET */
 148         return hp;
 149     } else {                            /* Try INET6 */
 150         if (hs)
 151             freehostent(hs);
 152         return (hs = getipnodebyname(host, AF_INET6, 0, &err));
 153     }
 154 #else
 155     return gethostbyname(host);
 156 #endif
 157 }
 158
 159 #ifdef HAVE_IPV6
 160 /*
 161  * When using IPv6 addresses, we'll be seeing lots of ":"s;
 162  * we require the addresses to be specified as [address].
 163  * An IPv6 address can be specified in 3 ways:
 164  *
 165  * x:x:x:x:x:x:x:x              (fully specified)
 166  * x::x:x:x:x                   (zeroes squashed)
 167  * ::FFFF:1.2.3.4               (IPv4 mapped)
 168  *
 169  * These need to be skipped to get at the ":" delimeters.
 170  *
 171  * We also allow a '/prefix' specifier.
 172  */
 173 char *skip_ipv6_addrs(str)
 174 char *str;
 175 {
 176     char *obr, *cbr, *colon;
 177     char *p = str;
 178     char *q;
 179
 180     while (1) {
 181         if ((colon = strchr(p, ':')) == NULL)
 182             return p;
 183         if ((obr = strchr(p, '[')) == NULL || obr > colon)
 184             return p;
 185         if ((cbr = strchr(obr, ']')) == NULL)
 186             return p;
 187
 188         for (q = obr + 1; q < cbr; q++) {
 189             /*
 190              * Quick and dirty parse, cheaper than inet_pton
 191              * Could count colons and dots (must be 0 or 3 dots, no
 192              * colons after dots seens, only one double :, etc, etc)
 193              */
 194             if (*q != ':' && *q != '.' && *q != '/' && !isxdigit(*q & 0xff))
 195                 return p;
 196         }
 197         p = cbr + 1;
 198     }
 199 }
 200 #endif /* HAVE_IPV6 */