/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2014 Zbigniew Jędrzejewski-Szmek

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <getopt.h>
#include <net/if.h>

#include "sd-bus.h"

#include "af-list.h"
#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
#include "escape.h"
#include "in-addr-util.h"
#include "parse-util.h"
#include "resolved-def.h"
#include "resolved-dns-packet.h"

#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC)

static int arg_family = AF_UNSPEC;
static int arg_ifindex = 0;
static uint16_t arg_type = 0;
static uint16_t arg_class = 0;
static bool arg_legend = true;
static uint64_t arg_flags = 0;
static bool arg_resolve_service = false;

static void print_source(uint64_t flags, usec_t rtt) {
        char rtt_str[FORMAT_TIMESTAMP_MAX];

        if (!arg_legend)
                return;

        if (flags == 0)
                return;

        fputs("\n-- Information acquired via", stdout);

        if (flags != 0)
                printf(" protocol%s%s%s",
                       flags & SD_RESOLVED_DNS ? " DNS" :"",
                       flags & SD_RESOLVED_LLMNR_IPV4 ? " LLMNR/IPv4" : "",
                       flags & SD_RESOLVED_LLMNR_IPV6 ? " LLMNR/IPv6" : "");

        assert_se(format_timespan(rtt_str, sizeof(rtt_str), rtt, 100));

        printf(" in %s", rtt_str);

        fputc('.', stdout);
        fputc('\n', stdout);

        printf("-- Data is authenticated: %s\n", yes_no(flags & SD_RESOLVED_AUTHENTICATED));
}

static int resolve_host(sd_bus *bus, const char *name) {

        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        const char *canonical = NULL;
        char ifname[IF_NAMESIZE] = "";
        unsigned c = 0;
        int r;
        uint64_t flags;
        usec_t ts;

        assert(name);

        if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname))
                return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex);

        log_debug("Resolving %s (family %s, interface %s).", name, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname);

        r = sd_bus_message_new_method_call(
                        bus,
                        &req,
                        "org.freedesktop.resolve1",
                        "/org/freedesktop/resolve1",
                        "org.freedesktop.resolve1.Manager",
                        "ResolveHostname");
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append(req, "isit", arg_ifindex, name, arg_family, arg_flags);
        if (r < 0)
                return bus_log_create_error(r);

        ts = now(CLOCK_MONOTONIC);

        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
        if (r < 0)
                return log_error_errno(r, "%s: resolve call failed: %s", name, bus_error_message(&error, r));

        ts = now(CLOCK_MONOTONIC) - ts;

        r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
        if (r < 0)
                return bus_log_parse_error(r);

        while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
                _cleanup_free_ char *pretty = NULL;
                int ifindex, family;
                const void *a;
                size_t sz;

                assert_cc(sizeof(int) == sizeof(int32_t));

                r = sd_bus_message_read(reply, "ii", &ifindex, &family);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_read_array(reply, 'y', &a, &sz);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_exit_container(reply);
                if (r < 0)
                        return bus_log_parse_error(r);

                if (!IN_SET(family, AF_INET, AF_INET6)) {
                        log_debug("%s: skipping entry with family %d (%s)", name, family, af_to_name(family) ?: "unknown");
                        continue;
                }

                if (sz != FAMILY_ADDRESS_SIZE(family)) {
                        log_error("%s: systemd-resolved returned address of invalid size %zu for family %s", name, sz, af_to_name(family) ?: "unknown");
                        return -EINVAL;
                }

                ifname[0] = 0;
                if (ifindex > 0 && !if_indextoname(ifindex, ifname))
                        log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex);

                r = in_addr_to_string(family, a, &pretty);
                if (r < 0)
                        return log_error_errno(r, "Failed to print address for %s: %m", name);

                printf("%*s%s %s%s%s\n",
                       (int) strlen(name), c == 0 ? name : "", c == 0 ? ":" : " ",
                       pretty,
                       isempty(ifname) ? "" : "%", ifname);

                c++;
        }
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_read(reply, "st", &canonical, &flags);
        if (r < 0)
                return bus_log_parse_error(r);

        if (!streq(name, canonical))
                printf("%*s%s (%s)\n",
                       (int) strlen(name), c == 0 ? name : "", c == 0 ? ":" : " ",
                       canonical);

        if (c == 0) {
                log_error("%s: no addresses found", name);
                return -ESRCH;
        }

        print_source(flags, ts);

        return 0;
}

static int resolve_address(sd_bus *bus, int family, const union in_addr_union *address, int ifindex) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        _cleanup_free_ char *pretty = NULL;
        char ifname[IF_NAMESIZE] = "";
        uint64_t flags;
        unsigned c = 0;
        usec_t ts;
        int r;

        assert(bus);
        assert(IN_SET(family, AF_INET, AF_INET6));
        assert(address);

        if (ifindex <= 0)
                ifindex = arg_ifindex;

        r = in_addr_to_string(family, address, &pretty);
        if (r < 0)
                return log_oom();

        if (ifindex > 0 && !if_indextoname(ifindex, ifname))
                return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex);

        log_debug("Resolving %s%s%s.", pretty, isempty(ifname) ? "" : "%", ifname);

        r = sd_bus_message_new_method_call(
                        bus,
                        &req,
                        "org.freedesktop.resolve1",
                        "/org/freedesktop/resolve1",
                        "org.freedesktop.resolve1.Manager",
                        "ResolveAddress");
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append(req, "ii", ifindex, family);
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append_array(req, 'y', address, FAMILY_ADDRESS_SIZE(family));
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append(req, "t", arg_flags);
        if (r < 0)
                return bus_log_create_error(r);

        ts = now(CLOCK_MONOTONIC);

        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
        if (r < 0) {
                log_error("%s: resolve call failed: %s", pretty, bus_error_message(&error, r));
                return r;
        }

        ts = now(CLOCK_MONOTONIC) - ts;

        r = sd_bus_message_enter_container(reply, 'a', "(is)");
        if (r < 0)
                return bus_log_create_error(r);

        while ((r = sd_bus_message_enter_container(reply, 'r', "is")) > 0) {
                const char *n;

                assert_cc(sizeof(int) == sizeof(int32_t));

                r = sd_bus_message_read(reply, "is", &ifindex, &n);
                if (r < 0)
                        return r;

                r = sd_bus_message_exit_container(reply);
                if (r < 0)
                        return r;

                ifname[0] = 0;
                if (ifindex > 0 && !if_indextoname(ifindex, ifname))
                        log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex);

                printf("%*s%*s%*s%s %s\n",
                       (int) strlen(pretty), c == 0 ? pretty : "",
                       isempty(ifname) ? 0 : 1, c > 0 || isempty(ifname) ? "" : "%",
                       (int) strlen(ifname), c == 0 ? ifname : "",
                       c == 0 ? ":" : " ",
                       n);

                c++;
        }
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_read(reply, "t", &flags);
        if (r < 0)
                return bus_log_parse_error(r);

        if (c == 0) {
                log_error("%s: no names found", pretty);
                return -ESRCH;
        }

        print_source(flags, ts);

        return 0;
}

static int parse_address(const char *s, int *family, union in_addr_union *address, int *ifindex) {
        const char *percent, *a;
        int ifi = 0;
        int r;

        percent = strchr(s, '%');
        if (percent) {
                if (parse_ifindex(percent+1, &ifi) < 0) {
                        ifi = if_nametoindex(percent+1);
                        if (ifi <= 0)
                                return -EINVAL;
                }

                a = strndupa(s, percent - s);
        } else
                a = s;

        r = in_addr_from_string_auto(a, family, address);
        if (r < 0)
                return r;

        *ifindex = ifi;
        return 0;
}

static int resolve_record(sd_bus *bus, const char *name) {

        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        char ifname[IF_NAMESIZE] = "";
        unsigned n = 0;
        uint64_t flags;
        int r;
        usec_t ts;

        assert(name);

        if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname))
                return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex);

        log_debug("Resolving %s %s %s (interface %s).", name, dns_class_to_string(arg_class), dns_type_to_string(arg_type), isempty(ifname) ? "*" : ifname);

        r = sd_bus_message_new_method_call(
                        bus,
                        &req,
                        "org.freedesktop.resolve1",
                        "/org/freedesktop/resolve1",
                        "org.freedesktop.resolve1.Manager",
                        "ResolveRecord");
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append(req, "isqqt", arg_ifindex, name, arg_class, arg_type, arg_flags);
        if (r < 0)
                return bus_log_create_error(r);

        ts = now(CLOCK_MONOTONIC);

        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
        if (r < 0) {
                log_error("%s: resolve call failed: %s", name, bus_error_message(&error, r));
                return r;
        }

        ts = now(CLOCK_MONOTONIC) - ts;

        r = sd_bus_message_enter_container(reply, 'a', "(iqqay)");
        if (r < 0)
                return bus_log_parse_error(r);

        while ((r = sd_bus_message_enter_container(reply, 'r', "iqqay")) > 0) {
                _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
                _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
                const char *s;
                uint16_t c, t;
                int ifindex;
                const void *d;
                size_t l;

                assert_cc(sizeof(int) == sizeof(int32_t));

                r = sd_bus_message_read(reply, "iqq", &ifindex, &c, &t);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_read_array(reply, 'y', &d, &l);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_exit_container(reply);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0);
                if (r < 0)
                        return log_oom();

                p->refuse_compression = true;

                r = dns_packet_append_blob(p, d, l, NULL);
                if (r < 0)
                        return log_oom();

                r = dns_packet_read_rr(p, &rr, NULL, NULL);
                if (r < 0)
                        return log_error_errno(r, "Failed to parse RR.");

                s = dns_resource_record_to_string(rr);
                if (!s) {
                        log_error("Failed to format RR.");
                        return -ENOMEM;
                }

                ifname[0] = 0;
                if (ifindex > 0 && !if_indextoname(ifindex, ifname))
                        log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex);

                printf("%s%s%s\n", s, isempty(ifname) ? "" : " # interface ", ifname);
                n++;
        }
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_read(reply, "t", &flags);
        if (r < 0)
                return bus_log_parse_error(r);

        if (n == 0) {
                log_error("%s: no records found", name);
                return -ESRCH;
        }

        print_source(flags, ts);

        return 0;
}

static int resolve_service(sd_bus *bus, const char *name, const char *type, const char *domain) {
        const char *canonical_name, *canonical_type, *canonical_domain;
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        char ifname[IF_NAMESIZE] = "";
        size_t indent, sz;
        uint64_t flags;
        const char *p;
        unsigned c;
        usec_t ts;
        int r;

        assert(bus);
        assert(domain);

        if (isempty(name))
                name = NULL;
        if (isempty(type))
                type = NULL;

        if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname))
                return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex);

        if (name)
                log_debug("Resolving service \"%s\" of type %s in %s (family %s, interface %s).", name, type, domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname);
        else if (type)
                log_debug("Resolving service type %s of %s (family %s, interface %s).", type, domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname);
        else
                log_debug("Resolving service type %s (family %s, interface %s).", domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname);

        r = sd_bus_message_new_method_call(
                        bus,
                        &req,
                        "org.freedesktop.resolve1",
                        "/org/freedesktop/resolve1",
                        "org.freedesktop.resolve1.Manager",
                        "ResolveService");
        if (r < 0)
                return bus_log_create_error(r);

        r = sd_bus_message_append(req, "isssit", arg_ifindex, name, type, domain, arg_family, arg_flags);
        if (r < 0)
                return bus_log_create_error(r);

        ts = now(CLOCK_MONOTONIC);

        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
        if (r < 0)
                return log_error_errno(r, "Resolve call failed: %s", bus_error_message(&error, r));

        ts = now(CLOCK_MONOTONIC) - ts;

        r = sd_bus_message_enter_container(reply, 'a', "(qqqsa(iiay)s)");
        if (r < 0)
                return bus_log_parse_error(r);

        indent =
                (name ? strlen(name) + 1 : 0) +
                (type ? strlen(type) + 1 : 0) +
                strlen(domain) + 2;

        c = 0;
        while ((r = sd_bus_message_enter_container(reply, 'r', "qqqsa(iiay)s")) > 0) {
                uint16_t priority, weight, port;
                const char *hostname, *canonical;

                r = sd_bus_message_read(reply, "qqqs", &priority, &weight, &port, &hostname);
                if (r < 0)
                        return bus_log_parse_error(r);

                if (name)
                        printf("%*s%s", (int) strlen(name), c == 0 ? name : "", c == 0 ? "/" : " ");
                if (type)
                        printf("%*s%s", (int) strlen(type), c == 0 ? type : "", c == 0 ? "/" : " ");

                printf("%*s%s %s:%u [priority=%u, weight=%u]\n",
                       (int) strlen(domain), c == 0 ? domain : "",
                       c == 0 ? ":" : " ",
                       hostname, port,
                       priority, weight);

                r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
                if (r < 0)
                        return bus_log_parse_error(r);

                while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
                        _cleanup_free_ char *pretty = NULL;
                        int ifindex, family;
                        const void *a;

                        assert_cc(sizeof(int) == sizeof(int32_t));

                        r = sd_bus_message_read(reply, "ii", &ifindex, &family);
                        if (r < 0)
                                return bus_log_parse_error(r);

                        r = sd_bus_message_read_array(reply, 'y', &a, &sz);
                        if (r < 0)
                                return bus_log_parse_error(r);

                        r = sd_bus_message_exit_container(reply);
                        if (r < 0)
                                return bus_log_parse_error(r);

                        if (!IN_SET(family, AF_INET, AF_INET6)) {
                                log_debug("%s: skipping entry with family %d (%s)", name, family, af_to_name(family) ?: "unknown");
                                continue;
                        }

                        if (sz != FAMILY_ADDRESS_SIZE(family)) {
                                log_error("%s: systemd-resolved returned address of invalid size %zu for family %s", name, sz, af_to_name(family) ?: "unknown");
                                return -EINVAL;
                        }

                        ifname[0] = 0;
                        if (ifindex > 0 && !if_indextoname(ifindex, ifname))
                                log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex);

                        r = in_addr_to_string(family, a, &pretty);
                        if (r < 0)
                                return log_error_errno(r, "Failed to print address for %s: %m", name);

                        printf("%*s%s%s%s\n", (int) indent, "", pretty, isempty(ifname) ? "" : "%s", ifname);
                }
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_exit_container(reply);
                if (r < 0)
                        return bus_log_parse_error(r);

                r = sd_bus_message_read(reply, "s", &canonical);
                if (r < 0)
                        return bus_log_parse_error(r);

                if (!streq(hostname, canonical))
                        printf("%*s(%s)\n", (int) indent, "", canonical);

                r = sd_bus_message_exit_container(reply);
                if (r < 0)
                        return bus_log_parse_error(r);

                c++;
        }
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_enter_container(reply, 'a', "ay");
        if (r < 0)
                return bus_log_parse_error(r);

        c = 0;
        while ((r = sd_bus_message_read_array(reply, 'y', (const void**) &p, &sz)) > 0) {
                _cleanup_free_ char *escaped = NULL;

                escaped = cescape_length(p, sz);
                if (!escaped)
                        return log_oom();

                printf("%*s%s\n", (int) indent, "", escaped);
                c++;
        }
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        r = sd_bus_message_read(reply, "ssst", &canonical_name, &canonical_type, &canonical_domain, &flags);
        if (r < 0)
                return bus_log_parse_error(r);

        if (isempty(canonical_name))
                canonical_name = NULL;
        if (isempty(canonical_type))
                canonical_type = NULL;

        if (!streq_ptr(name, canonical_name) ||
            !streq_ptr(type, canonical_type) ||
            !streq_ptr(domain, canonical_domain)) {

                printf("%*s(", (int) indent, "");

                if (canonical_name)
                        printf("%s/", canonical_name);
                if (canonical_type)
                        printf("%s/", canonical_type);

                printf("%s)\n", canonical_domain);
        }

        print_source(flags, ts);

        return 0;
}

static void help_dns_types(void) {
        int i;
        const char *t;

        if (arg_legend)
                puts("Known DNS RR types:");
        for (i = 0; i < _DNS_TYPE_MAX; i++) {
                t = dns_type_to_string(i);
                if (t)
                        puts(t);
        }
}

static void help_dns_classes(void) {
        int i;
        const char *t;

        if (arg_legend)
                puts("Known DNS RR classes:");
        for (i = 0; i < _DNS_CLASS_MAX; i++) {
                t = dns_class_to_string(i);
                if (t)
                        puts(t);
        }
}

static void help(void) {
        printf("%s [OPTIONS...] NAME...\n"
               "%s [OPTIONS...] --service [[NAME] TYPE] DOMAIN\n\n"
               "Resolve domain names, IPv4 or IPv6 addresses, resource records, and services.\n\n"
               "  -h --help                 Show this help\n"
               "     --version              Show package version\n"
               "  -4                        Resolve IPv4 addresses\n"
               "  -6                        Resolve IPv6 addresses\n"
               "  -i INTERFACE              Look on interface\n"
               "  -p --protocol=PROTOCOL    Look via protocol\n"
               "  -t --type=TYPE            Query RR with DNS type\n"
               "  -c --class=CLASS          Query RR with DNS class\n"
               "     --service              Resolve service (SRV)\n"
               "     --service-address=BOOL Do [not] resolve address for services\n"
               "     --service-txt=BOOL     Do [not] resolve TXT records for services\n"
               "     --cname=BOOL           Do [not] follow CNAME redirects\n"
               "     --search=BOOL          Do [not] use search domains\n"
               "     --legend=BOOL          Do [not] print column headers\n"
               , program_invocation_short_name, program_invocation_short_name);
}

static int parse_argv(int argc, char *argv[]) {
        enum {
                ARG_VERSION = 0x100,
                ARG_LEGEND,
                ARG_SERVICE,
                ARG_CNAME,
                ARG_SERVICE_ADDRESS,
                ARG_SERVICE_TXT,
                ARG_SEARCH,
        };

        static const struct option options[] = {
                { "help",            no_argument,       NULL, 'h'                 },
                { "version",         no_argument,       NULL, ARG_VERSION         },
                { "type",            required_argument, NULL, 't'                 },
                { "class",           required_argument, NULL, 'c'                 },
                { "legend",          required_argument, NULL, ARG_LEGEND          },
                { "protocol",        required_argument, NULL, 'p'                 },
                { "cname",           required_argument, NULL, ARG_CNAME           },
                { "service",         no_argument,       NULL, ARG_SERVICE         },
                { "service-address", required_argument, NULL, ARG_SERVICE_ADDRESS },
                { "service-txt",     required_argument, NULL, ARG_SERVICE_TXT     },
                { "search",          required_argument, NULL, ARG_SEARCH          },
                {}
        };

        int c, r;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "h46i:t:c:p:", options, NULL)) >= 0)
                switch(c) {

                case 'h':
                        help();
                        return 0; /* done */;

                case ARG_VERSION:
                        return version();

                case '4':
                        arg_family = AF_INET;
                        break;

                case '6':
                        arg_family = AF_INET6;
                        break;

                case 'i': {
                        int ifi;

                        if (parse_ifindex(optarg, &ifi) >= 0)
                                arg_ifindex = ifi;
                        else {
                                ifi = if_nametoindex(optarg);
                                if (ifi <= 0)
                                        return log_error_errno(errno, "Unknown interface %s: %m", optarg);

                                arg_ifindex = ifi;
                        }

                        break;
                }

                case 't':
                        if (streq(optarg, "help")) {
                                help_dns_types();
                                return 0;
                        }

                        r = dns_type_from_string(optarg);
                        if (r < 0) {
                                log_error("Failed to parse RR record type %s", optarg);
                                return r;
                        }
                        arg_type = (uint16_t) r;
                        assert((int) arg_type == r);

                        break;

                case 'c':
                        if (streq(optarg, "help")) {
                                help_dns_classes();
                                return 0;
                        }

                        r = dns_class_from_string(optarg);
                        if (r < 0) {
                                log_error("Failed to parse RR record class %s", optarg);
                                return r;
                        }
                        arg_class = (uint16_t) r;
                        assert((int) arg_class == r);

                        break;

                case ARG_LEGEND:
                        r = parse_boolean(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse --legend= argument");

                        arg_legend = r;
                        break;

                case 'p':
                        if (streq(optarg, "dns"))
                                arg_flags |= SD_RESOLVED_DNS;
                        else if (streq(optarg, "llmnr"))
                                arg_flags |= SD_RESOLVED_LLMNR;
                        else if (streq(optarg, "llmnr-ipv4"))
                                arg_flags |= SD_RESOLVED_LLMNR_IPV4;
                        else if (streq(optarg, "llmnr-ipv6"))
                                arg_flags |= SD_RESOLVED_LLMNR_IPV6;
                        else {
                                log_error("Unknown protocol specifier: %s", optarg);
                                return -EINVAL;
                        }

                        break;

                case ARG_SERVICE:
                        arg_resolve_service = true;
                        break;

                case ARG_CNAME:
                        r = parse_boolean(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse --cname= argument.");
                        if (r == 0)
                                arg_flags |= SD_RESOLVED_NO_CNAME;
                        else
                                arg_flags &= ~SD_RESOLVED_NO_CNAME;
                        break;

                case ARG_SERVICE_ADDRESS:
                        r = parse_boolean(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse --service-address= argument.");
                        if (r == 0)
                                arg_flags |= SD_RESOLVED_NO_ADDRESS;
                        else
                                arg_flags &= ~SD_RESOLVED_NO_ADDRESS;
                        break;

                case ARG_SERVICE_TXT:
                        r = parse_boolean(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse --service-txt= argument.");
                        if (r == 0)
                                arg_flags |= SD_RESOLVED_NO_TXT;
                        else
                                arg_flags &= ~SD_RESOLVED_NO_TXT;
                        break;

                case ARG_SEARCH:
                        r = parse_boolean(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse --search argument.");
                        if (r == 0)
                                arg_flags |= SD_RESOLVED_NO_SEARCH;
                        else
                                arg_flags &= ~SD_RESOLVED_NO_SEARCH;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        if (arg_type == 0 && arg_class != 0) {
                log_error("--class= may only be used in conjunction with --type=.");
                return -EINVAL;
        }

        if (arg_type != 0 && arg_resolve_service) {
                log_error("--service and --type= may not be combined.");
                return -EINVAL;
        }

        if (arg_type != 0 && arg_class == 0)
                arg_class = DNS_CLASS_IN;

        return 1 /* work to do */;
}

int main(int argc, char **argv) {
        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
        int r;

        log_parse_environment();
        log_open();

        r = parse_argv(argc, argv);
        if (r <= 0)
                goto finish;

        if (optind >= argc) {
                log_error("No arguments passed");
                r = -EINVAL;
                goto finish;
        }

        r = sd_bus_open_system(&bus);
        if (r < 0) {
                log_error_errno(r, "sd_bus_open_system: %m");
                goto finish;
        }

        if (arg_resolve_service) {

                if (argc < optind + 1) {
                        log_error("Domain specification required.");
                        r = -EINVAL;
                        goto finish;

                } else if (argc == optind + 1)
                        r = resolve_service(bus, NULL, NULL, argv[optind]);
                else if (argc == optind + 2)
                        r = resolve_service(bus, NULL, argv[optind], argv[optind+1]);
                else if (argc == optind + 3)
                        r = resolve_service(bus, argv[optind], argv[optind+1], argv[optind+2]);
                else {
                        log_error("Too many arguments");
                        r = -EINVAL;
                        goto finish;
                }

                goto finish;
        }

        while (argv[optind]) {
                int family, ifindex, k;
                union in_addr_union a;

                if (arg_type != 0)
                        k = resolve_record(bus, argv[optind]);
                else {
                        k = parse_address(argv[optind], &family, &a, &ifindex);
                        if (k >= 0)
                                k = resolve_address(bus, family, &a, ifindex);
                        else
                                k = resolve_host(bus, argv[optind]);
                }

                if (r == 0)
                        r = k;

                optind++;
        }

finish:
        return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}