source: code/dns.c@ 9440414

/*
 * Copyright (c) 2014 Mike Belopuhov
 * Copyright (c) 2014 Eric Faurot <eric@faurot.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <event.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>

#include <asr.h>

#include "icb.h"
#include "icbd.h"

void dns_done_host(struct asr_result *, void *);
void dns_done_reverse(struct asr_result *, void *);

extern int dodns;

void
dns_done_host(struct asr_result *ar, void *arg)
{
        struct icb_session *is = arg;

        if (ar->ar_addrinfo)
                freeaddrinfo(ar->ar_addrinfo);

        /* just check that there's no error */
        if (ar->ar_gai_errno == 0) {
                if (strncmp(is->hostname, "localhost",
                    sizeof "localhost" - 1) == 0)
                        strlcpy(is->host, "unknown", ICB_MAXHOSTLEN);
                else if (strlen(is->hostname) < ICB_MAXHOSTLEN)
                        strlcpy(is->host, is->hostname, ICB_MAXHOSTLEN);
        } else
                icbd_log(is, LOG_WARNING, "dns resolution failed: %s",
                    gai_strerror(ar->ar_gai_errno));
}

void
dns_done_reverse(struct asr_result *ar, void *arg)
{
        struct icb_session *is = arg;
        struct asr_query *as;
        struct addrinfo hints;

        if (ar->ar_gai_errno == 0) {
                icbd_log(is, LOG_DEBUG, "reverse dns resolved %s to %s",
                    is->host, is->hostname);
                /* try to verify that it resolves back */
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = PF_UNSPEC;
                as = getaddrinfo_async(is->hostname, NULL, &hints, NULL);
                event_asr_run(as, dns_done_host, is);
        } else
                icbd_log(is, LOG_WARNING, "reverse dns resolution failed: %s",
                    gai_strerror(ar->ar_gai_errno));
}

void
dns_resolve(struct icb_session *is, struct sockaddr *sa)
{
        struct asr_query *as;

        if (!dodns)
                return;

        if (verbose)
                icbd_log(is, LOG_DEBUG, "resolving: %s", is->host);

        as = getnameinfo_async(sa, sa->sa_len, is->hostname,
            sizeof is->hostname, NULL, 0, NI_NOFQDN, NULL);
        event_asr_run(as, dns_done_reverse, is);
}