diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/mts/sendmail/hosts.c

   1 /* hosts.c - find out the official name of a host */
   2 #ifndef lint
   3 static char ident[] = "@(#)$Id: hosts.c,v 1.7 1992/12/15 00:20:22 jromine Exp $";
   4 #endif  /* lint */
   5
   6 /* LINTLIBRARY */
   7
   8 /* In the SendMail world, we really don't know what the valid hosts are.
   9    We could poke around in the sendmail.cf file, but that still isn't a
  10    guarantee.  As a result, we'll say that everything is a valid host, and
  11    let SendMail worry about it. */
  12
  13
  14 #include "../h/strings.h"
  15 #include <stdio.h>
  16 #include "../zotnet/mts.h"
  17 #include <ctype.h>
  18 #if     defined(BSD42) || defined(SOCKETS)
  19 #include <netdb.h>
  20 #endif  /* BSD42 or SOCKETS */
  21
  22
  23 #define NOTOK   (-1)
  24
  25
  26 static struct host {
  27     char   *h_name;
  28     char  **h_aliases;
  29     struct host   *h_next;
  30 }                   hosts;
  31
  32 char   *getcpy ();
  33
  34 static int      init_hs();
  35
  36 /* \f */
  37
  38 char   *OfficialName (name)
  39 register char   *name;
  40 {
  41     register char  *p;
  42     char   *q,
  43             site[BUFSIZ];
  44 #if     defined(BSD42) || defined(SOCKETS)
  45     register struct hostent *hp;
  46 #endif  /* BSD42 or SOCKETS */
  47     static char buffer[BUFSIZ];
  48     register char **r;
  49     register struct host   *h;
  50
  51     for (p = name, q = site; *p; p++, q++)
  52         *q = isupper (*p) ? tolower (*p) : *p;
  53     *q = 0;
  54     q = site;
  55
  56     if (uleq (LocalName (), site))
  57         return LocalName ();
  58
  59 #ifdef  BSD41A
  60     if (rhost (&q) != NOTOK) {
  61         (void) strcpy (buffer, q);
  62         free (q);
  63         return buffer;
  64     }
  65 #endif  /* BSD41A */
  66 #if     defined(BSD42) || defined(SOCKETS)
  67 #ifndef BIND
  68     sethostent (1);
  69 #endif
  70     if (hp = gethostbyname (q)) {
  71         (void) strcpy (buffer, hp -> h_name);
  72         return buffer;
  73     }
  74 #endif  /* BSD42 or SOCKETS */
  75
  76     if (hosts.h_name || init_hs ())
  77         for (h = hosts.h_next; h; h = h -> h_next)
  78             if (uleq (h -> h_name, q))
  79                 return h -> h_name;
  80             else
  81                 for (r = h -> h_aliases; *r; r++)
  82                     if (uleq (*r, q))
  83                         return h -> h_name;
  84
  85     (void) strcpy (buffer, site);
  86     return buffer;
  87 }
  88
  89 /* \f */
  90
  91 /* Use hostable as an exception file for those hosts that aren't on the
  92    Internet (listed in /etc/hosts).  These are usually PhoneNet and UUCP
  93    sites. */
  94
  95
  96 #define NALIASES        50
  97
  98 static int  init_hs () {
  99     register char  *cp,
 100                    *dp,
 101                   **q,
 102                   **r;
 103     char    buffer[BUFSIZ],
 104            *aliases[NALIASES];
 105     register struct host   *h;
 106     register FILE  *fp;
 107
 108     if ((fp = fopen (hostable, "r")) == NULL)
 109         return 0;
 110
 111     h = &hosts;
 112     while (fgets (buffer, sizeof buffer, fp) != NULL) {
 113         if (cp = index (buffer, '#'))
 114             *cp = 0;
 115         if (cp = index (buffer, '\n'))
 116             *cp = 0;
 117         for (cp = buffer; *cp; cp++)
 118             if (isspace (*cp))
 119                 *cp = ' ';
 120         for (cp = buffer; isspace (*cp); cp++)
 121             continue;
 122         if (*cp == 0)
 123             continue;
 124
 125         q = aliases;
 126         if (cp = index (dp = cp, ' ')) {
 127             *cp = 0;
 128             for (cp++; *cp; cp++) {
 129                 while (isspace (*cp))
 130                     cp++;
 131                 if (*cp == 0)
 132                     break;
 133                 if (cp = index (*q++ = cp, ' '))
 134                     *cp = 0;
 135                 else
 136                     break;
 137                 if (q >= aliases + NALIASES)
 138                     break;
 139             }
 140         }
 141
 142         *q = 0;
 143
 144         h -> h_next = (struct host *) calloc (1, sizeof *h);
 145         h = h -> h_next;
 146         h -> h_name = getcpy (dp);
 147         r = h -> h_aliases =
 148                 (char **) calloc ((unsigned) (q - aliases + 1), sizeof *q);
 149         for (q = aliases; *q; q++)
 150             *r++ = getcpy (*q);
 151         *r = 0;
 152     }
 153
 154     (void) fclose (fp);
 155     return 1;
 156 }