Revert "resolvectl: Add show-multicast verb to show discovered LLMNR/mDNS hosts"

fix conservative_renameat()

man/org.freedesktop.resolve1.xml

@@ -115,7 +115,6 @@ node /org/freedesktop/resolve1 {
       ResetStatistics();
       FlushCaches();
       ResetServerFeatures();
-      GetMulticastHosts(out a(stiiay) UNNAMED);
     properties:
       readonly s LLMNRHostname = '...';
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
@@ -165,8 +164,6 @@ node /org/freedesktop/resolve1 {
 
     <!--method ResetServerFeatures is not documented!-->
 
-    <!--method GetMulticastHosts is not documented!-->
-
     <!--property DNSSECNegativeTrustAnchors is not documented!-->
 
     <!--Autogenerated cross-references for systemd.directives, do not edit-->
@@ -215,8 +212,6 @@ node /org/freedesktop/resolve1 {
 
     <variablelist class="dbus-method" generated="True" extra-ref="ResetServerFeatures()"/>
 
-    <variablelist class="dbus-method" generated="True" extra-ref="GetMulticastHosts()"/>
-
     <variablelist class="dbus-property" generated="True" extra-ref="LLMNRHostname"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="LLMNR"/>

man/resolvectl.xml

@@ -180,13 +180,6 @@
         automatically, an explicit reverting is not necessary in that case.</para></listitem>
       </varlistentry>
 
-      <varlistentry>
-        <term><command>show-multicast</command></term>
-
-        <listitem><para>Display the discovered LLMNR and mDNS hostnames along with their IPv4/IPv6 addresses.
-        </para></listitem>
-      </varlistentry>
-
       <xi:include href="systemctl.xml" xpointer="log-level" />
     </variablelist>
   </refsect1>

mkosi.postinst

@@ -1,5 +0,0 @@
-#!/bin/sh
-set -e
-
-mkdir -p /root/build
-echo "directory /root/build" > ~/.gdbinit

src/basic/fs-util.c

@@ -1656,23 +1656,37 @@ int conservative_renameat(
                 goto do_rename;
 
         for (;;) {
-                char buf1[16*1024];
-                char buf2[sizeof(buf1) + 1];
+                uint8_t buf1[16*1024];
+                uint8_t buf2[sizeof(buf1)];
                 ssize_t l1, l2;
 
                 l1 = read(old_fd, buf1, sizeof(buf1));
                 if (l1 < 0)
                         goto do_rename;
 
-                l2 = read(new_fd, buf2, l1 + 1);
-                if (l1 != l2)
-                        goto do_rename;
+                if (l1 == sizeof(buf1))
+                        /* Read the full block, hence read a full block in the other file too */
 
-                if (l1 == 0) /* EOF on both! And everything's the same so far, yay! */
-                        break;
+                        l2 = read(new_fd, buf2, l1);
+                else {
+                        assert((size_t) l1 < sizeof(buf1));
+
+                        /* Short read. This hence was the last block in the first file, and then came
+                         * EOF. Read one byte more in the second file, so that we can verify we hit EOF there
+                         * too. */
+
+                        assert((size_t) (l1 + 1) <= sizeof(buf2));
+                        l2 = read(new_fd, buf2, l1 + 1);
+                }
+                if (l2 != l1)
+                        goto do_rename;
 
                 if (memcmp(buf1, buf2, l1) != 0)
                         goto do_rename;
+
+                if ((size_t) l1 < sizeof(buf1)) /* We hit EOF on the first file, and the second file too, hence exit
+                                                 * now. */
+                        break;
         }
 
 is_same:

src/resolve/resolvectl.c

@@ -2500,90 +2500,6 @@ static int verb_log_level(int argc, char *argv[], void *userdata) {
         return 0;
 }
 
-static const char *resolve_flags_to_string(uint64_t flags) {
-        return flags & SD_RESOLVED_DNS         ? "DNS" :
-                flags & SD_RESOLVED_LLMNR_IPV4 ? "LLMNR/IPv4" :
-                flags & SD_RESOLVED_LLMNR_IPV6 ? "LLMNR/IPv6" :
-                flags & SD_RESOLVED_MDNS_IPV4  ? "mDNS/IPv4" :
-                flags & SD_RESOLVED_MDNS_IPV6  ? "mDNS/IPv6" :
-                                                 "";
-}
-
-static int verb_show_multicast(int argc, char *argv[], void *userdata) {
-        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
-        _cleanup_(table_unrefp) Table *table = NULL;
-        sd_bus *bus = userdata;
-        int r;
-
-        assert(bus);
-
-        table = table_new("Hostname", "Address", "Source");
-        if (!table)
-                return log_oom();
-
-        r = bus_call_method(bus, bus_resolve_mgr, "GetMulticastHosts", &error, &reply, NULL);
-        if (r < 0)
-                return log_error_errno(r, "Failed to query systemd-resolved: %s", bus_error_message(&error, r));
-
-        r = sd_bus_message_enter_container(reply, 'a', "(stiiay)");
-        if (r < 0)
-                return bus_log_parse_error(r);
-
-        while ((r = sd_bus_message_enter_container(reply, 'r', "stiiay")) > 0) {
-                char *canonical;
-                uint64_t flags;
-                _cleanup_free_ char *pretty = NULL;
-                int ifindex, family;
-                union in_addr_union a;
-
-                r = sd_bus_message_read(reply, "st", &canonical, &flags);
-                if (r < 0)
-                        return bus_log_parse_error(r);
-
-                r = sd_bus_message_read(reply, "i", &ifindex);
-                if (r < 0)
-                        return bus_log_parse_error(r);
-
-                sd_bus_error_free(&error);
-                r = bus_message_read_in_addr_auto(reply, &error, &family, &a);
-                if (r < 0)
-                        return log_error_errno(
-                                r,
-                                "systemd-resolved returned invalid result: %s",
-                                bus_error_message(&error, r));
-
-                r = sd_bus_message_exit_container(reply);
-                if (r < 0)
-                        return bus_log_parse_error(r);
-
-                r = in_addr_ifindex_to_string(family, &a, ifindex, &pretty);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to print address: %m");
-
-                r = table_add_many(
-                        table,
-                        TABLE_STRING,
-                        canonical,
-                        TABLE_STRING,
-                        pretty,
-                        TABLE_STRING,
-                        resolve_flags_to_string(flags));
-                if (r < 0)
-                        return table_log_add_error(r);
-        }
-
-        r = sd_bus_message_exit_container(reply);
-        if (r < 0)
-                return bus_log_parse_error(r);
-
-        r = table_print(table, NULL);
-        if (r < 0)
-                return table_log_print_error(r);
-
-        return 0;
-}
-
 static void help_protocol_types(void) {
         if (arg_legend)
                 puts("Known protocol types:");
@@ -2693,7 +2609,6 @@ static int native_help(void) {
                "  nta [LINK [DOMAIN...]]       Get/set per-interface DNSSEC NTA\n"
                "  revert LINK                  Revert per-interface configuration\n"
                "  log-level [LEVEL]            Get/set logging threshold for systemd-resolved\n"
-               "  show-multicast               Show domain names discovered via LLMNR/mDNS\n"
                "\nOptions:\n"
                "  -h --help                    Show this help\n"
                "     --version                 Show package version\n"
@@ -3237,7 +3152,7 @@ static int native_parse_argv(int argc, char *argv[]) {
 }
 
 static int native_main(int argc, char *argv[], sd_bus *bus) {
-        /* clang-format off */
+
         static const Verb verbs[] = {
                 { "help",                  VERB_ANY, VERB_ANY, 0,            verb_help             },
                 { "status",                VERB_ANY, VERB_ANY, VERB_DEFAULT, verb_status           },
@@ -3259,10 +3174,8 @@ static int native_main(int argc, char *argv[], sd_bus *bus) {
                 { "nta",                   VERB_ANY, VERB_ANY, 0,            verb_nta              },
                 { "revert",                VERB_ANY, 2,        0,            verb_revert_link      },
                 { "log-level",             VERB_ANY, 2,        0,            verb_log_level        },
-                { "show-multicast",        VERB_ANY, VERB_ANY, 0,            verb_show_multicast   },
                 {}
         };
-        /* clang-format on */
 
         return dispatch_verb(argc, argv, verbs, bus);
 }

src/resolve/resolved-bus.c

@@ -132,17 +132,15 @@ static int reply_query_state(DnsQuery *q) {
         }
 }
 
-static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex, bool is_container) {
+static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex) {
         int r;
 
         assert(reply);
         assert(rr);
 
-        if (is_container) {
-                r = sd_bus_message_open_container(reply, 'r', "iiay");
-                if (r < 0)
-                        return r;
-        }
+        r = sd_bus_message_open_container(reply, 'r', "iiay");
+        if (r < 0)
+                return r;
 
         r = sd_bus_message_append(reply, "i", ifindex);
         if (r < 0)
@@ -167,11 +165,9 @@ static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifin
         if (r < 0)
                 return r;
 
-        if (is_container) {
-                r = sd_bus_message_close_container(reply);
-                if (r < 0)
-                        return r;
-        }
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
 
         return 0;
 }
@@ -220,7 +216,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
                 if (r == 0)
                         continue;
 
-                r = append_address(reply, rr, ifindex, true);
+                r = append_address(reply, rr, ifindex);
                 if (r < 0)
                         goto finish;
 
@@ -855,7 +851,7 @@ static int append_srv(DnsQuery *q, sd_bus_message *reply, DnsResourceRecord *rr)
                                 if (r == 0)
                                         continue;
 
-                                r = append_address(reply, zz, ifindex, true);
+                                r = append_address(reply, zz, ifindex);
                                 if (r < 0)
                                         return r;
                         }
@@ -2004,76 +2000,6 @@ static int bus_method_unregister_service(sd_bus_message *message, void *userdata
         return call_dnssd_method(m, message, bus_dnssd_method_unregister, error);
 }
 
-static int bus_method_get_multicast_hosts(sd_bus_message *message, void *userdata, sd_bus_error *error) {
-        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
-        DnsScope *s;
-        Manager *m = userdata;
-        int r;
-
-        assert(message);
-        assert(m);
-
-        r = sd_bus_message_new_method_return(message, &reply);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_message_open_container(reply, 'a', "(stiiay)");
-        if (r < 0)
-                return r;
-
-        LIST_FOREACH(scopes, s, m->dns_scopes) {
-                _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
-                DnsResourceRecord *rr;
-                DnsAnswerFlags flags;
-                int ifindex;
-
-                if (s->protocol == DNS_PROTOCOL_DNS)
-                        continue;
-
-                r = dns_cache_dump_to_answer(&s->cache, &answer);
-                if (r < 0)
-                        return r;
-                if (r == 0)
-                        continue;
-
-                DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, answer) {
-                        _cleanup_free_ char *normalized = NULL;
-                        bool authenticated = FLAGS_SET(flags, DNS_ANSWER_AUTHENTICATED);
-
-                        r = dns_name_normalize(dns_resource_key_name(rr->key), 0, &normalized);
-                        if (r < 0)
-                                return r;
-
-                        r = sd_bus_message_open_container(reply, 'r', "stiiay");
-                        if (r < 0)
-                                return r;
-
-                        r = sd_bus_message_append(
-                                reply,
-                                "st",
-                                normalized,
-                                SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, authenticated));
-                        if (r < 0)
-                                return r;
-
-                        r = append_address(reply, rr, ifindex, false);
-                        if (r < 0)
-                                return r;
-
-                        r = sd_bus_message_close_container(reply);
-                        if (r < 0)
-                                return r;
-                }
-        }
-
-        r = sd_bus_message_close_container(reply);
-        if (r < 0)
-                return r;
-
-        return sd_bus_reply(message, reply);
-}
-
-/* clang-format off */
 static const sd_bus_vtable resolve_vtable[] = {
         SD_BUS_VTABLE_START(0),
         SD_BUS_PROPERTY("LLMNRHostname", "s", NULL, offsetof(Manager, llmnr_hostname), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
@@ -2212,14 +2138,9 @@ static const sd_bus_vtable resolve_vtable[] = {
                                 SD_BUS_NO_RESULT,
                                 bus_method_reset_server_features,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
-        SD_BUS_METHOD_WITH_ARGS("GetMulticastHosts",
-                                SD_BUS_NO_ARGS,
-                                SD_BUS_RESULT("a(stiiay)", addresses),
-                                bus_method_get_multicast_hosts,
-                                SD_BUS_VTABLE_UNPRIVILEGED),
+
         SD_BUS_VTABLE_END,
 };
-/* clang-format on */
 
 const BusObjectImplementation manager_object = {
         "/org/freedesktop/resolve1",

src/resolve/resolved-dns-cache.c

@@ -1066,55 +1066,7 @@ int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p) {
         return 0;
 }
 
-int dns_cache_dump_to_answer(DnsCache *cache, DnsAnswer **ret) {
-        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
-        DnsCacheItem *i;
-        size_t n = 0;
-        int r;
-
-        assert(cache);
-        assert(ret);
-
-        HASHMAP_FOREACH(i, cache->by_key) {
-                DnsCacheItem *j;
-
-                LIST_FOREACH(by_key, j, i) {
-                        if (!j->rr)
-                                continue;
-
-                        n++;
-                }
-        }
-
-        if (n == 0) {
-                *ret = NULL;
-                return 0;
-        }
-
-        answer = dns_answer_new(n);
-        if (!answer)
-                return -ENOMEM;
-
-        HASHMAP_FOREACH(i, cache->by_key) {
-                DnsCacheItem *j;
-
-                LIST_FOREACH(by_key, j, i) {
-                        if (!j->rr)
-                                continue;
-
-                        r = dns_answer_add(
-                                answer, j->rr, j->ifindex, j->authenticated ? DNS_ANSWER_AUTHENTICATED : 0);
-                        if (r < 0)
-                                return r;
-                }
-        }
-
-        *ret = TAKE_PTR(answer);
-
-        return n;
-}
-
-void dns_cache_dump_to_file(DnsCache *cache, FILE *f) {
+void dns_cache_dump(DnsCache *cache, FILE *f) {
         DnsCacheItem *i;
 
         if (!cache)

src/resolve/resolved-dns-cache.h

@@ -27,8 +27,7 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, bool clamp_ttl, int *rcod
 
 int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address);
 
-void dns_cache_dump_to_file(DnsCache *cache, FILE *f);
-int dns_cache_dump_to_answer(DnsCache *cache, DnsAnswer **answer);
+void dns_cache_dump(DnsCache *cache, FILE *f);
 bool dns_cache_is_empty(DnsCache *cache);
 
 unsigned dns_cache_size(DnsCache *cache);

src/resolve/resolved-dns-scope.c

@@ -1159,7 +1159,7 @@ void dns_scope_dump(DnsScope *s, FILE *f) {
 
         if (!dns_cache_is_empty(&s->cache)) {
                 fputs("CACHE:\n", f);
-                dns_cache_dump_to_file(&s->cache, f);
+                dns_cache_dump(&s->cache, f);
         }
 }
 

src/test/test-fs-util.c

@@ -11,6 +11,7 @@
 #include "macro.h"
 #include "mkdir.h"
 #include "path-util.h"
+#include "random-util.h"
 #include "rm-rf.h"
 #include "stdio-util.h"
 #include "string-util.h"
@@ -836,12 +837,24 @@ static void test_path_is_encrypted(void) {
         test_path_is_encrypted_one("/dev", booted > 0 ? false : -1);
 }
 
+static void create_binary_file(const char *p, const void *data, size_t l) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(p, O_CREAT|O_WRONLY|O_EXCL|O_CLOEXEC, 0600);
+        assert_se(fd >= 0);
+        assert_se(write(fd, data, l) == (ssize_t) l);
+}
+
 static void test_conservative_rename(void) {
         _cleanup_(unlink_and_freep) char *p = NULL;
         _cleanup_free_ char *q = NULL;
+        size_t l = 16*1024 + random_u64() % (32 * 1024); /* some randomly sized buffer 16k…48k */
+        uint8_t buffer[l+1];
+
+        random_bytes(buffer, l);
 
         assert_se(tempfn_random_child(NULL, NULL, &p) >= 0);
-        assert_se(write_string_file(p, "this is a test", WRITE_STRING_FILE_CREATE) >= 0);
+        create_binary_file(p, buffer, l);
 
         assert_se(tempfn_random_child(NULL, NULL, &q) >= 0);
 
@@ -856,27 +869,30 @@ static void test_conservative_rename(void) {
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 
         /* Check that a manual new writeout is also detected */
-        assert_se(write_string_file(q, "this is a test", WRITE_STRING_FILE_CREATE) >= 0);
+        create_binary_file(q, buffer, l);
         assert_se(conservative_renameat(AT_FDCWD, q, AT_FDCWD, p) == 0);
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 
         /* Check that a minimally changed version is detected */
-        assert_se(write_string_file(q, "this is a_test", WRITE_STRING_FILE_CREATE) >= 0);
+        buffer[47] = ~buffer[47];
+        create_binary_file(q, buffer, l);
         assert_se(conservative_renameat(AT_FDCWD, q, AT_FDCWD, p) > 0);
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 
         /* Check that this really is new updated version */
-        assert_se(write_string_file(q, "this is a_test", WRITE_STRING_FILE_CREATE) >= 0);
+        create_binary_file(q, buffer, l);
         assert_se(conservative_renameat(AT_FDCWD, q, AT_FDCWD, p) == 0);
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 
         /* Make sure we detect extended files */
-        assert_se(write_string_file(q, "this is a_testx", WRITE_STRING_FILE_CREATE) >= 0);
+        buffer[l++] = 47;
+        create_binary_file(q, buffer, l);
         assert_se(conservative_renameat(AT_FDCWD, q, AT_FDCWD, p) > 0);
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 
         /* Make sure we detect truncated files */
-        assert_se(write_string_file(q, "this is a_test", WRITE_STRING_FILE_CREATE) >= 0);
+        l--;
+        create_binary_file(q, buffer, l);
         assert_se(conservative_renameat(AT_FDCWD, q, AT_FDCWD, p) > 0);
         assert_se(access(q, F_OK) < 0 && errno == ENOENT);
 }