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