diplodocus.org Git - nmh/blob - mts/smtp/hosts.c

   1
   2 /*
   3  * hosts.c -- find out the official name of a host
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 /*
  13  * In the SendMail world, we really don't know what the valid
  14  * hosts are.  We could poke around in the sendmail.cf file, but
  15  * that still isn't a guarantee.  As a result, we'll say that
  16  * everything is a valid host, and let SendMail worry about it.
  17  */
  18
  19 #include <h/mh.h>
  20 #include <h/mts.h>
  21 #include <netdb.h>
  22
  23 static struct host {
  24     char *h_name;
  25     char **h_aliases;
  26     struct host *h_next;
  27 } hosts;
  28
  29
  30 /*
  31  * static prototypes
  32  */
  33 static int init_hs(void);
  34
  35
  36 char *
  37 OfficialName (char *name)
  38 {
  39     char *p, *q, site[BUFSIZ];
  40     struct hostent *hp;
  41
  42     static char buffer[BUFSIZ];
  43     char **r;
  44     struct host *h;
  45
  46     for (p = name, q = site; *p && (q - site < sizeof(site) - 1); p++, q++)
  47         *q = isupper (*p) ? tolower (*p) : *p;
  48     *q = '\0';
  49     q = site;
  50
  51     if (!strcasecmp (LocalName(), site))
  52         return LocalName();
  53
  54 #ifdef  HAVE_SETHOSTENT
  55     sethostent (1);
  56 #endif
  57
  58     if ((hp = gethostbyname (q))) {
  59         strncpy (buffer, hp->h_name, sizeof(buffer));
  60         return buffer;
  61     }
  62     if (hosts.h_name || init_hs ()) {
  63         for (h = hosts.h_next; h; h = h->h_next)
  64             if (!strcasecmp (h->h_name, q)) {
  65                 return h->h_name;
  66             } else {
  67                 for (r = h->h_aliases; *r; r++)
  68                     if (!strcasecmp (*r, q))
  69                         return h->h_name;
  70             }
  71     }
  72
  73     strncpy (buffer, site, sizeof(buffer));
  74     return buffer;
  75 }
  76
  77 /*
  78  * Use hostable as an exception file for those hosts that aren't
  79  * on the Internet (listed in /etc/hosts).  These are usually
  80  * PhoneNet and UUCP sites.
  81  */
  82
  83 #define NALIASES 50
  84
  85 static int
  86 init_hs (void)
  87 {
  88     char  *cp, *dp, **q, **r;
  89     char buffer[BUFSIZ], *aliases[NALIASES];
  90     register struct host *h;
  91     register FILE  *fp;
  92
  93     if ((fp = fopen (hostable, "r")) == NULL)
  94         return 0;
  95
  96     h = &hosts;
  97     while (fgets (buffer, sizeof(buffer), fp) != NULL) {
  98         if ((cp = strchr(buffer, '#')))
  99             *cp = 0;
 100         if ((cp = strchr(buffer, '\n')))
 101             *cp = 0;
 102         for (cp = buffer; *cp; cp++)
 103             if (isspace (*cp))
 104                 *cp = ' ';
 105         for (cp = buffer; isspace (*cp); cp++)
 106             continue;
 107         if (*cp == 0)
 108             continue;
 109
 110         q = aliases;
 111         if ((cp = strchr(dp = cp, ' '))) {
 112             *cp = 0;
 113             for (cp++; *cp; cp++) {
 114                 while (isspace (*cp))
 115                     cp++;
 116                 if (*cp == 0)
 117                     break;
 118                 if ((cp = strchr(*q++ = cp, ' ')))
 119                     *cp = 0;
 120                 else
 121                     break;
 122                 if (q >= aliases + NALIASES)
 123                     break;
 124             }
 125         }
 126
 127         *q = 0;
 128
 129         h->h_next = (struct host *) calloc (1, sizeof(*h));
 130         h = h->h_next;
 131         h->h_name = getcpy (dp);
 132         r = h->h_aliases =
 133                 (char **) calloc ((size_t) (q - aliases + 1), sizeof(*q));
 134         for (q = aliases; *q; q++)
 135             *r++ = getcpy (*q);
 136         *r = 0;
 137     }
 138
 139     fclose (fp);
 140     return 1;
 141 }