/*      $NetBSD: whois.c,v 1.38 2020/03/01 02:26:16 sevan Exp $    */
/*      $OpenBSD: whois.c,v 1.58 2018/06/19 11:28:11 jca Exp $   */

/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>

#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static const char sccsid[] = "@(#)whois.c       8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: whois.c,v 1.38 2020/03/01 02:26:16 sevan Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#define ANICHOST        "whois.arin.net"
#define BNICHOST        "whois.registro.br"
#define CNICHOST        "whois.corenic.net"
#define DNICHOST        "whois.nic.mil"
#define FNICHOST        "whois.afrinic.net"
#define GNICHOST        "whois.nic.gov"
#define IANAHOST        "whois.iana.org"
#define INICHOST        "whois.networksolutions.com"
#define LNICHOST        "whois.lacnic.net"
#define MNICHOST        "whois.ra.net"
#define NICHOST         "whois.crsnic.net"
#define PDBHOST         "whois.peeringdb.com"
#define PNICHOST        "whois.apnic.net"
#define QNICHOST_TAIL   ".whois-servers.net"
#define RNICHOST        "whois.ripe.net"
#define RUNICHOST       "whois.ripn.net"

#define WHOIS_PORT      "whois"
#define WHOIS_SERVER_ID "Registrar WHOIS Server:"

#define WHOIS_RECURSE           0x01
#define WHOIS_QUICK             0x02

static const char *port_whois = WHOIS_PORT;
static const char *ip_whois[] =
    { LNICHOST, RNICHOST, PNICHOST, FNICHOST, BNICHOST, NULL };

static void usage(void) __dead;
static int whois(const char *, const char *, const char *, int);
static const char *choose_server(const char *, const char *, char **);

int
main(int argc, char *argv[])
{
        int ch, flags, rval;
        const char *host, *name, *country;

        country = host = NULL;
        flags = rval = 0;
        while ((ch = getopt(argc, argv, "Aac:dfgh:Iilmp:PqQRr")) != -1)
                switch (ch) {
                case 'a':
                        host = ANICHOST;
                        break;
                case 'A':
                        host = PNICHOST;
                        break;
                case 'c':
                        country = optarg;
                        break;
                case 'd':
                        host = DNICHOST;
                        break;
                case 'f':
                        host = FNICHOST;
                        break;
                case 'g':
                        host = GNICHOST;
                        break;
                case 'h':
                        host = optarg;
                        break;
                case 'i':
                        host = INICHOST;
                        break;
                case 'I':
                        host = IANAHOST;
                        break;
                case 'l':
                        host = LNICHOST;
                        break;
                case 'm':
                        host = MNICHOST;
                        break;
                case 'p':
                        port_whois = optarg;
                        break;
                case 'P':
                        host = PDBHOST;
                        break;
                case 'q':
                        /* deprecated, now the default */
                        break;
                case 'Q':
                        flags |= WHOIS_QUICK;
                        break;
                case 'r':
                        host = RNICHOST;
                        break;
                case 'R':
                        host = RUNICHOST;
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (!argc || (country != NULL && host != NULL))
                usage();

        if (host == NULL && country == NULL && !(flags & WHOIS_QUICK))
                flags |= WHOIS_RECURSE;
        for (name = *argv; (name = *argv) != NULL; argv++) {
                char *tofree = NULL;
                const char *server =
                    host ? host : choose_server(name, country, &tofree);
                rval += whois(name, server, port_whois, flags);
                free(tofree);
        }
        return (rval);
}

static int
whois(const char *query, const char *server, const char *port, int flags)
{
        FILE *fp;
        char *buf, *p, *nhost, *nbuf = NULL;
        size_t len;
        int i, s, error;
        const char *reason = NULL, *fmt;
        struct addrinfo hints, *res, *ai;

        (void)memset(&hints, 0, sizeof(hints));
        hints.ai_flags = 0;
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        error = getaddrinfo(server, port, &hints, &res);
        if (error) {
                if (error == EAI_SERVICE)
                        warnx("%s: bad port", port);
                else
                        warnx("%s: %s", server, gai_strerror(error));
                return (1);
        }

        for (s = -1, ai = res; ai != NULL; ai = ai->ai_next) {
                s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (s < 0) {
                        error = errno;
                        reason = "socket";
                        continue;
                }
                if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
                        error = errno;
                        reason = "connect";
                        close(s);
                        s = -1;
                        continue;
                }
                break;  /*okay*/
        }
        freeaddrinfo(res);
        if (s < 0) {
                if (reason) {
                        errno = error;
                        warn("%s: %s", server, reason);
                } else
                        warnx("Unknown error in connection attempt");
                return (1);
        }

        if (strcmp(server, "whois.denic.de") == 0 ||
            strcmp(server, "de" QNICHOST_TAIL) == 0)
                fmt = "-T dn,ace -C ISO-8859-1 ";
        else if (strcmp(server, "whois.dk-hostmaster.dk") == 0 ||
            strcmp(server, "dk" QNICHOST_TAIL) == 0)
                fmt = "--show-handles ";
        else
                fmt = "";

        fp = fdopen(s, "r+");
        if (fp == NULL)
                err(1, "fdopen");
        (void)fprintf(fp, "%s%s\r\n", fmt, query);
        (void)fflush(fp);
        nhost = NULL;
        while ((buf = fgetln(fp, &len)) != NULL) {
                p = buf + len - 1;
                if (isspace((unsigned char)*p)) {
                        do
                                *p = '\0';
                        while (p > buf && isspace((unsigned char)*--p));
                } else {
                        if ((nbuf = malloc(len + 1)) == NULL)
                                err(1, "malloc");
                        (void)memcpy(nbuf, buf, len);
                        nbuf[len] = '\0';
                        buf = nbuf;
                }
                (void)puts(buf);

                if (nhost != NULL || !(flags & WHOIS_RECURSE))
                        continue;

                if ((p = strstr(buf, WHOIS_SERVER_ID))) {
                        p += sizeof(WHOIS_SERVER_ID) - 1;
                        while (isblank((unsigned char)*p))
                                p++;
                        if ((len = strcspn(p, " \t\n\r"))) {
                                if ((nhost = malloc(len + 1)) == NULL)
                                        err(1, "malloc");
                                (void)memcpy(nhost, p, len);
                                nhost[len] = '\0';
                        }
                } else if (strcmp(server, ANICHOST) == 0) {
                        for (p = buf; *p != '\0'; p++)
                                *p = tolower((unsigned char)*p);
                        for (i = 0; ip_whois[i] != NULL; i++) {
                                if (strstr(buf, ip_whois[i]) != NULL) {
                                        nhost = strdup(ip_whois[i]);
                                        if (nhost == NULL)
                                                err(1, "strdup");
                                        break;
                                }
                        }
                }
        }
        fclose(fp);
        free(nbuf);

        if (nhost != NULL) {
                error = whois(query, nhost, port, 0);
                free(nhost);
        }

        return (error);
}

/*
 * If no country is specified determine the top level domain from the query.
 * If the TLD is a number, query ARIN, otherwise, use TLD.whois-server.net.
 * If the domain does not contain '.', check to see if it is an NSI handle
 * (starts with '!') or a CORE handle (COCO-[0-9]+ or COHO-[0-9]+) or an
 * ASN (starts with AS) or IPv6 address (contains ':'). Fall back to
 * NICHOST for the non-handle and non-IPv6 case.
 */
static const char *
choose_server(const char *name, const char *country, char **tofree)
{
        static char *server;
        const char *qhead;
        char *ep;
        struct addrinfo hints, *res = NULL;

        (void)memset(&hints, 0, sizeof(hints));
        hints.ai_flags = 0;
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;

        if (country != NULL)
                qhead = country;
        else if ((qhead = strrchr(name, '.')) == NULL) {
                if (*name == '!')
                        return (INICHOST);
                else if ((strncasecmp(name, "COCO-", 5) == 0 ||
                    strncasecmp(name, "COHO-", 5) == 0) &&
                    strtol(name + 5, &ep, 10) > 0 && *ep == '\0')
                        return (CNICHOST);
                else if ((strncasecmp(name, "AS", 2) == 0) &&
                    strtol(name + 2, &ep, 10) > 0 && *ep == '\0')
                        return (MNICHOST);
                else if (strchr(name, ':') != NULL) /* IPv6 address */
                        return (ANICHOST);
                else
                        return (NICHOST);
        } else if (isdigit((unsigned char)*(++qhead)))
                return (ANICHOST);

        /*
         * Post-2003 ("new") gTLDs are all supposed to have "whois.nic.domain"
         * (per registry agreement), some older gTLDs also support this...
         */
        if (asprintf(&server, "whois.nic.%s", qhead) == -1)
                err(1, NULL);

        /* most ccTLDs don't do this, but QNICHOST/whois-servers mostly works */
        if ((strlen(qhead) == 2 ||
            /* and is required for most of the <=2003 TLDs/gTLDs */
            strcasecmp(qhead, "org") == 0 ||
            strcasecmp(qhead, "com") == 0 ||
            strcasecmp(qhead, "net") == 0 ||
            strcasecmp(qhead, "cat") == 0 ||
            strcasecmp(qhead, "pro") == 0 ||
            strcasecmp(qhead, "info") == 0 ||
            strcasecmp(qhead, "aero") == 0 ||
            strcasecmp(qhead, "jobs") == 0 ||
            strcasecmp(qhead, "mobi") == 0 ||
            strcasecmp(qhead, "museum") == 0 ||
             /* for others, if whois.nic.TLD doesn't exist, try whois-servers */
            getaddrinfo(server, NULL, &hints, &res) != 0)) {
                free(server);
                if (asprintf(&server, "%s%s", qhead, QNICHOST_TAIL) == -1)
                        err(1, NULL);
        }
        if (res != NULL)
                freeaddrinfo(res);

        *tofree = server;
        return (server);
}

static void
usage(void)
{
        (void)fprintf(stderr,
            "usage: %s [-AadfgIilmPQRr] [-c country-code | -h host] "
                "[-p port] name ...\n", getprogname());
        exit(1);
}