mx.c

/*
 * Part of DNS zone file validator `validns`.
 *
 * Copyright 2011-2014 Anton Berezin <tobez@tobez.org>
 * Modified BSD license.
 * (See LICENSE file in the distribution.)
 *
 */
#include <sys/types.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "common.h"
#include "textparse.h"
#include "mempool.h"
#include "carp.h"
#include "rr.h"

static struct rr *mx_parse(char *name, long ttl, int type, char *s)
{
    struct rr_mx *rr = getmem(sizeof(*rr));

    rr->preference = extract_integer(&s, "MX preference", NULL);
    if (rr->preference < 0)
        return NULL;
    /* XXX preference range check */
    rr->exchange = extract_name(&s, "MX exchange", 0);
    if (!rr->exchange)
        return NULL;
    if (*s) {
        return bitch("garbage after valid MX data");
    }

    return store_record(type, name, ttl, rr);
}

static char* mx_human(struct rr *rrv)
{
    RRCAST(mx);
    char s[1024];

    snprintf(s, 1024, "%d %s",
         rr->preference, rr->exchange);
    return quickstrdup_temp(s);
}

static struct binary_data mx_wirerdata(struct rr *rrv)
{
    RRCAST(mx);

    return compose_binary_data("2d", 1,
        rr->preference, name2wire_name(rr->exchange));
}

static void* mx_validate_set(struct rr_set *rr_set)
{
    if (rr_set->named_rr->flags & NAME_FLAG_CONTAINS_SLASH) {
        struct rr *rr = rr_set->tail;
        return moan(rr->file_name, rr->line, "host name contains '/'");
    }
    return NULL;
}

static void *mx_validate(struct rr *rrv)
{
    RRCAST(mx);

    if (G.opt.policy_checks[POLICY_MX_ALIAS]) {
        if (find_rr_set(T_CNAME, rr->exchange)) {
            return moan(rr->rr.file_name, rr->rr.line, "MX exchange is an alias");
        }
    }
    return NULL;
}

struct rr_methods mx_methods = { mx_parse, mx_human, mx_wirerdata, mx_validate_set, mx_validate };