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

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