resolved: add tool to query resolved

.gitignore

@@ -100,6 +100,7 @@
 /systemd-remount-api-vfs
 /systemd-remount-fs
 /systemd-reply-password
+/systemd-resolve-host
 /systemd-resolved
 /systemd-rfkill
 /systemd-run

Makefile.am

@@ -4847,6 +4847,16 @@ libnss_resolve_la_LIBADD = \
 lib_LTLIBRARIES += \
 	libnss_resolve.la
 
+systemd_resolve_host_SOURCES = \
+	src/resolve-host/resolve-host.c
+
+systemd_resolve_host_LDADD = \
+	libsystemd-internal.la \
+	libsystemd-shared.la
+
+rootlibexec_PROGRAMS += \
+	systemd-resolve-host
+
 endif
 
 # ------------------------------------------------------------------------------

src/resolve-host/Makefile

@@ -0,0 +1 @@
+../Makefile

src/resolve-host/resolve-host.c

@@ -0,0 +1,270 @@
+/*-*- 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 <arpa/inet.h>
+#include <net/if.h>
+#include <getopt.h>
+
+#include "sd-bus.h"
+#include "bus-util.h"
+#include "bus-error.h"
+#include "bus-errors.h"
+#include "in-addr-util.h"
+#include "af-list.h"
+#include "build.h"
+
+#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC)
+
+static int arg_family = AF_UNSPEC;
+static int arg_ifindex = 0;
+
+static int resolve_host(sd_bus *bus, const char *name, int _family, int _ifindex) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *req = NULL, *reply = NULL;
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        unsigned c = 0;
+        int r;
+
+        assert(name);
+
+        log_debug("Resolving %s (family %s)",
+                  name, af_to_name(_family));
+
+        r = sd_bus_message_new_method_call(
+                        bus,
+                        &req,
+                        "org.freedesktop.resolve1",
+                        "/org/freedesktop/resolve1",
+                        "org.freedesktop.resolve1.Manager",
+                        "ResolveHostname");
+        if (r < 0) {
+                log_error("sd_bus_message_new_method_call: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_message_set_auto_start(req, false);
+        if (r < 0) {
+                log_error("sd_bus_message_set_auto_start: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_message_append(req, "si", name, AF_UNSPEC);
+        if (r < 0) {
+                log_error("sd_bus_message_append: %s", strerror(-r));
+                return r;
+        }
+
+        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;
+        }
+
+        r = sd_bus_message_enter_container(reply, 'a', "(iayi)");
+        if (r < 0) {
+                log_error("%s: failed to parse reply: %s", name, bus_error_message(&error, r));
+                return r;
+        }
+
+        while ((r = sd_bus_message_enter_container(reply, 'r', "iayi")) > 0) {
+                const void *a;
+                int family, ifindex;
+                size_t sz;
+                _cleanup_free_ char *pretty = NULL;
+                char ifname[IF_NAMESIZE] = "";
+
+                r = sd_bus_message_read(reply, "i", &family);
+                if (r < 0) {
+                        log_error("Cannot parse message, aborting.");
+                        return -EBADMSG;
+                }
+
+                r = sd_bus_message_read_array(reply, 'y', &a, &sz);
+                if (r < 0) {
+                        log_error("Cannot parse message, aborting.");
+                        return -EBADMSG;
+                }
+
+                r = sd_bus_message_read(reply, "i", &ifindex);
+                if (r < 0) {
+                        log_error("Cannot parse message, aborting.");
+                        return -EBADMSG;
+                }
+
+                r = sd_bus_message_exit_container(reply);
+                if (r < 0) {
+                        log_error("Cannot parse message, aborting.");
+                        return -EBADMSG;
+                }
+
+                if ((_family != AF_UNSPEC && family != _family) ||
+                    !IN_SET(family, AF_INET, AF_INET6)) {
+                        log_debug("%s: skipping entry with family %hu (%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");
+                        continue;
+                }
+
+                if (ifindex < 0) {
+                        log_error("%s: systemd-resolved returned invalid interface index %i",
+                                  name, ifindex);
+                        continue;
+                }
+
+                if (ifindex > 0) {
+                        char *t;
+
+                        t = if_indextoname(ifindex, ifname);
+                        if (!t) {
+                                log_error("Failed to resolve interface name for index %i", ifindex);
+                                continue;
+                        }
+                }
+
+                if (_ifindex > 0 && ifindex > 0 && ifindex != _ifindex) {
+                        log_debug("%s: skipping entry with ifindex %i (%s)",
+                                  name, ifindex, ifname);
+                        continue;
+                }
+
+                r = in_addr_to_string(family, a, &pretty);
+                if (r < 0) {
+                        log_error("%s: failed to print address: %s", name, strerror(-r));
+                        continue;
+                }
+
+                log_info("%*s%s %s%s%.*s",
+                         (int) strlen(name), c == 0 ? name : "", c == 0 ? ":" : " ",
+                         pretty,
+                         *ifname ? "%" : "", (int) sizeof(ifname), *ifname ? ifname: "");
+
+                c++;
+        }
+
+        if (c == 0) {
+                log_error("%s: no addresses found", name);
+                return -ENONET;
+        }
+
+        return sd_bus_message_exit_container(reply);
+}
+
+static void help(void) {
+        printf("%s [OPTIONS...]\n\n"
+               "Resolve IPv4 or IPv6 addresses.\n\n"
+               "Options:\n"
+               "  -4                       Resolve IPv4 addresses\n"
+               "  -6                       Resolve IPv6 addresses\n"
+               "  -i INTERFACE             Filter by interface\n"
+               "  -h --help                Show this help and exit\n"
+               "  --version                Print version string and exit\n"
+               , program_invocation_short_name
+               );
+}
+
+static int parse_argv(int argc, char *argv[]) {
+        enum {
+                ARG_VERSION = 0x100,
+        };
+
+        static const struct option options[] = {
+                { "help",        no_argument,       NULL, 'h'           },
+                { "version",     no_argument,       NULL, ARG_VERSION   },
+                {}
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h46i:", options, NULL)) >= 0)
+                switch(c) {
+
+                case 'h':
+                        help();
+                        return 0; /* done */;
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(SYSTEMD_FEATURES);
+                        return 0 /* done */;
+
+                case '4':
+                        arg_family = AF_INET;
+                        break;
+
+                case '6':
+                        arg_family = AF_INET6;
+                        break;
+
+                case 'i':
+                        arg_ifindex = if_nametoindex(optarg);
+                        if (arg_ifindex <= 0) {
+                                log_error("Unknown interfaces %s: %m", optarg);
+                                return -EINVAL;
+                        }
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        return 1 /* work to do */;
+}
+
+
+int main(int argc, char **argv) {
+        _cleanup_bus_unref_ sd_bus *bus = NULL;
+        int r;
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto end;
+
+        r = sd_bus_open_system(&bus);
+        if (r < 0) {
+                log_error("sd_bus_open_system: %s", strerror(-r));
+                goto end;
+        }
+
+        while (argv[optind]) {
+                int k;
+
+                k = resolve_host(bus, argv[optind++], arg_family, arg_ifindex);
+                if (r == 0)
+                        r = k;
+        }
+
+ end:
+        return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}