source: trunk/third/nmh/mts/smtp/hosts.c @ 12455

/*
 * hosts.c -- find out the official name of a host
 *
 * $Id: hosts.c,v 1.1.1.1 1999-02-07 18:14:12 danw Exp $
 */

/*
 * In the SendMail world, we really don't know what the valid
 * hosts are.  We could poke around in the sendmail.cf file, but
 * that still isn't a guarantee.  As a result, we'll say that
 * everything is a valid host, and let SendMail worry about it.
 */

#include <h/mh.h>
#include <zotnet/mts/mts.h>
#include <netdb.h>

static struct host {
    char *h_name;
    char **h_aliases;
    struct host *h_next;
} hosts;


/*
 * static prototypes
 */
static int init_hs(void);


char *
OfficialName (char *name)
{
    char *p, *q, site[BUFSIZ];
    struct hostent *hp;

    static char buffer[BUFSIZ];
    char **r;
    struct host *h;

    for (p = name, q = site; *p && (q - site < sizeof(site) - 1); p++, q++)
        *q = isupper (*p) ? tolower (*p) : *p;
    *q = '\0';
    q = site;

    if (!strcasecmp (LocalName(), site))
        return LocalName();

#ifndef BIND
    sethostent (1);
#endif

    if ((hp = gethostbyname (q))) {
        strncpy (buffer, hp->h_name, sizeof(buffer));
        return buffer;
    }
    if (hosts.h_name || init_hs ())
        for (h = hosts.h_next; h; h = h->h_next)
            if (!strcasecmp (h->h_name, q))
                return h->h_name;
            else
                for (r = h->h_aliases; *r; r++)
                    if (!strcasecmp (*r, q))
                        return h->h_name;

    strncpy (buffer, site, sizeof(buffer));
    return buffer;
}

/*
 * Use hostable as an exception file for those hosts that aren't
 * on the Internet (listed in /etc/hosts).  These are usually
 * PhoneNet and UUCP sites.
 */

#define NALIASES 50

static int
init_hs (void)
{
    char  *cp, *dp, **q, **r;
    char buffer[BUFSIZ], *aliases[NALIASES];
    register struct host *h;
    register FILE  *fp;

    if ((fp = fopen (hostable, "r")) == NULL)
        return 0;

    h = &hosts;
    while (fgets (buffer, sizeof(buffer), fp) != NULL) {
        if ((cp = strchr(buffer, '#')))
            *cp = 0;
        if ((cp = strchr(buffer, '\n')))
            *cp = 0;
        for (cp = buffer; *cp; cp++)
            if (isspace (*cp))
                *cp = ' ';
        for (cp = buffer; isspace (*cp); cp++)
            continue;
        if (*cp == 0)
            continue;

        q = aliases;
        if ((cp = strchr(dp = cp, ' '))) {
            *cp = 0;
            for (cp++; *cp; cp++) {
                while (isspace (*cp))
                    cp++;
                if (*cp == 0)
                    break;
                if ((cp = strchr(*q++ = cp, ' ')))
                    *cp = 0;
                else
                    break;
                if (q >= aliases + NALIASES)
                    break;
            }
        }

        *q = 0;

        h->h_next = (struct host *) calloc (1, sizeof(*h));
        h = h->h_next;
        h->h_name = getcpy (dp);
        r = h->h_aliases =
                (char **) calloc ((size_t) (q - aliases + 1), sizeof(*q));
        for (q = aliases; *q; q++)
            *r++ = getcpy (*q);
        *r = 0;
    }

    fclose (fp);
    return 1;
}