aboutsummaryrefslogtreecommitdiffstats
path: root/dist-tools/shipper/README
Commit message (Expand)AuthorAgeFilesLines
* Move shipper to dist-tools directoryRob Funk2004-06-181-0/+7
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 12:55:29 +0000
'#n39'>39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 
/*
 * mxget.c -- fetch MX records for given DNS name
 *
 * Copyright 1997 by Eric S. Raymond
 * For license terms, see the file COPYING in this directory.
 */

#include "config.h"
#ifdef HAVE_RES_SEARCH
#include <stdio.h>
#include <string.h>
#ifdef HAVE_NET_SOCKET_H
#include <net/socket.h>
#endif
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>

#ifdef __BEOS__
#include "beos/beos_nameser.h"
#endif

#ifdef HAVE_ARPA_NAMESER_H
#include <arpa/nameser.h>
#endif
#ifdef HAVE_RESOLV_H
#include <resolv.h>
#endif

#include "mx.h"

/*
 * This ought to be in the bind library.  It's adapted from sendmail.
 */

/*
 * These are defined in RFC833. Some bind interface headers don't declare them.
 * Ghod help us if they're ever actually incompatible with what's in 
 * the arpa/nameser.h header.
 */
#ifndef PACKETSZ
#define PACKETSZ	512		/* maximum packet size */
#endif
#ifndef HFIXEDSZ
#define	HFIXEDSZ	12		/* #/bytes of fixed data in header */
#endif
#ifndef INT32SZ
#define	INT32SZ		4		/* for systems without 32-bit ints */
#endif
#ifndef INT16SZ
#define	INT16SZ		2		/* for systems without 16-bit ints */
#endif

/* minimum possible size of MX record in packet */
#define MIN_MX_SIZE	8	/* corresp to "a.com 0" w/ terminating space */

struct mxentry *getmxrecords(const char *name)
/* get MX records for given host */
{
    char answer[PACKETSZ], *eom, *cp, *bp;
    int n, ancount, qdcount, buflen, type, pref, ind;
    static struct mxentry pmx[(PACKETSZ - HFIXEDSZ) / MIN_MX_SIZE];
    static char MXHostBuf[PACKETSZ - HFIXEDSZ]; 
    HEADER *hp;

    pmx->name = (char *)NULL;
    pmx->pref = -1;
    n = res_search(name, C_IN,T_MX, (unsigned char *)&answer, sizeof(answer));
    if (n == -1)
	return((struct mxentry *)NULL);
    if (n > sizeof(answer))
	n = sizeof(answer);    	

    hp = (HEADER *)&answer;
    cp = answer + HFIXEDSZ;
    eom = answer + n;
    h_errno = 0;
    for (qdcount = ntohs(hp->qdcount); qdcount--; cp += n + QFIXEDSZ)
	if ((n = dn_skipname(cp, eom)) < 0)
	    return((struct mxentry *)NULL);
    buflen = sizeof(MXHostBuf) - 1;
    bp = MXHostBuf;
    ind = 0;
    ancount = ntohs(hp->ancount);
    while (--ancount >= 0 && cp < eom)
    {
	if ((n = dn_expand(answer, eom, cp, bp, buflen)) < 0)
	    break;
	cp += n;
	GETSHORT(type, cp);
	cp += INT16SZ + INT32SZ;
	GETSHORT(n, cp);
	if (type != T_MX)
	{
	    cp += n;
	    continue;
	}
	GETSHORT(pref, cp);
	if ((n = dn_expand(answer, eom, cp, bp, buflen)) < 0)
	    break;
	cp += n;

	pmx[ind].name = bp;
	pmx[ind].pref = pref;
	++ind;

	n = strlen((const char *)bp);
	bp += n;
	*bp++ = '\0';

	buflen -= n + 1;
    }

    pmx[ind].name = (char *)NULL;
    pmx[ind].pref = -1;
    return(pmx);
}
#endif /* HAVE_RES_SEARCH */

#ifdef STANDALONE
#include <stdlib.h>

int main(int argc, char *argv[])
{
    int	count, i;
    struct mxentry *responses;

    if (argc != 2 || 0 == strcmp(argv[1], "-h")) {
	fprintf(stderr, "Usage: %s domain\n", argv[0]);
	exit(1);
    }

    responses = getmxrecords(argv[1]);
    if (responses == (struct mxentry *)NULL)
	puts("No MX records found");
    else
	do {
	    printf("%s %d\n", responses->name, responses->pref);
	} while
	    ((++responses)->name);
}
#endif /* TESTMAIN */

/* mxget.c ends here */