]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/libsystemd/sd-resolve/sd-resolve.c
sd-resolve: suppress false positive MSan warnings
[thirdparty/systemd.git] / src / libsystemd / sd-resolve / sd-resolve.c
index 787642a7fb9c16aa421192071544eeedec85d7bc..00a6464e2d653647d58d3b3d4b39a3b08fbac4bf 100644 (file)
@@ -1,22 +1,4 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
-/***
-  This file is part of systemd.
-
-  Copyright 2005-2008 Lennart Poettering
-
-  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 <errno.h>
 #include <poll.h>
 
 #include "alloc-util.h"
 #include "dns-domain.h"
+#include "errno-util.h"
 #include "fd-util.h"
 #include "io-util.h"
 #include "list.h"
+#include "memory-util.h"
 #include "missing.h"
-#include "socket-util.h"
-#include "util.h"
 #include "process-util.h"
+#include "resolve-private.h"
+#include "socket-util.h"
 
 #define WORKERS_MIN 1U
 #define WORKERS_MAX 16U
@@ -112,6 +96,7 @@ struct sd_resolve_query {
         };
 
         void *userdata;
+        sd_resolve_destroy_t destroy_callback;
 
         LIST_FIELDS(sd_resolve_query, queries);
 };
@@ -181,8 +166,15 @@ static void resolve_query_disconnect(sd_resolve_query *q);
 #define RESOLVE_DONT_DESTROY(resolve) \
         _cleanup_(sd_resolve_unrefp) _unused_ sd_resolve *_dont_destroy_##resolve = sd_resolve_ref(resolve)
 
-static int send_died(int out_fd) {
+static void query_assign_errno(sd_resolve_query *q, int ret, int error, int h_error) {
+        assert(q);
 
+        q->ret = ret;
+        q->_errno = abs(error);
+        q->_h_errno = h_error;
+}
+
+static int send_died(int out_fd) {
         RHeader rh = {
                 .type = RESPONSE_DIED,
                 .length = sizeof(RHeader),
@@ -211,12 +203,14 @@ static void *serialize_addrinfo(void *p, const struct addrinfo *ai, size_t *leng
         if (*length + l > maxlength)
                 return NULL;
 
-        s.ai_flags = ai->ai_flags;
-        s.ai_family = ai->ai_family;
-        s.ai_socktype = ai->ai_socktype;
-        s.ai_protocol = ai->ai_protocol;
-        s.ai_addrlen = ai->ai_addrlen;
-        s.canonname_len = cnl;
+        s = (AddrInfoSerialization) {
+                .ai_flags = ai->ai_flags,
+                .ai_family = ai->ai_family,
+                .ai_socktype = ai->ai_socktype,
+                .ai_protocol = ai->ai_protocol,
+                .ai_addrlen = ai->ai_addrlen,
+                .canonname_len = cnl,
+        };
 
         memcpy((uint8_t*) p, &s, sizeof(AddrInfoSerialization));
         memcpy((uint8_t*) p + sizeof(AddrInfoSerialization), ai->ai_addr, ai->ai_addrlen);
@@ -235,7 +229,17 @@ static int send_addrinfo_reply(
                 int _errno,
                 int _h_errno) {
 
-        AddrInfoResponse resp = {
+        AddrInfoResponse resp = {};
+        union {
+                AddrInfoSerialization ais;
+                uint8_t space[BUFSIZE];
+        } buffer;
+        struct iovec iov[2];
+        struct msghdr mh;
+
+        assert(out_fd >= 0);
+
+        resp = (AddrInfoResponse) {
                 .header.type = RESPONSE_ADDRINFO,
                 .header.id = id,
                 .header.length = sizeof(AddrInfoResponse),
@@ -244,14 +248,7 @@ static int send_addrinfo_reply(
                 ._h_errno = _h_errno,
         };
 
-        struct msghdr mh = {};
-        struct iovec iov[2];
-        union {
-                AddrInfoSerialization ais;
-                uint8_t space[BUFSIZE];
-        } buffer;
-
-        assert(out_fd >= 0);
+        msan_unpoison(&resp, sizeof(resp));
 
         if (ret == 0 && ai) {
                 void *p = &buffer;
@@ -269,11 +266,13 @@ static int send_addrinfo_reply(
         if (ai)
                 freeaddrinfo(ai);
 
-        iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(AddrInfoResponse) };
-        iov[1] = (struct iovec) { .iov_base = &buffer, .iov_len = resp.header.length - sizeof(AddrInfoResponse) };
+        iov[0] = IOVEC_MAKE(&resp, sizeof(AddrInfoResponse));
+        iov[1] = IOVEC_MAKE(&buffer, resp.header.length - sizeof(AddrInfoResponse));
 
-        mh.msg_iov = iov;
-        mh.msg_iovlen = ELEMENTSOF(iov);
+        mh = (struct msghdr) {
+                .msg_iov = iov,
+                .msg_iovlen = ELEMENTSOF(iov)
+        };
 
         if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0)
                 return -errno;
@@ -290,16 +289,9 @@ static int send_nameinfo_reply(
                 int _errno,
                 int _h_errno) {
 
-        NameInfoResponse resp = {
-                .header.type = RESPONSE_NAMEINFO,
-                .header.id = id,
-                .ret = ret,
-                ._errno = _errno,
-                ._h_errno = _h_errno,
-        };
-
-        struct msghdr mh = {};
+        NameInfoResponse resp = {};
         struct iovec iov[3];
+        struct msghdr mh;
         size_t hl, sl;
 
         assert(out_fd >= 0);
@@ -307,16 +299,27 @@ static int send_nameinfo_reply(
         sl = serv ? strlen(serv)+1 : 0;
         hl = host ? strlen(host)+1 : 0;
 
-        resp.header.length = sizeof(NameInfoResponse) + hl + sl;
-        resp.hostlen = hl;
-        resp.servlen = sl;
+        resp = (NameInfoResponse) {
+                .header.type = RESPONSE_NAMEINFO,
+                .header.id = id,
+                .header.length = sizeof(NameInfoResponse) + hl + sl,
+                .hostlen = hl,
+                .servlen = sl,
+                .ret = ret,
+                ._errno = _errno,
+                ._h_errno = _h_errno,
+        };
+
+        msan_unpoison(&resp, sizeof(resp));
 
-        iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(NameInfoResponse) };
-        iov[1] = (struct iovec) { .iov_base = (void*) host, .iov_len = hl };
-        iov[2] = (struct iovec) { .iov_base = (void*) serv, .iov_len = sl };
+        iov[0] = IOVEC_MAKE(&resp, sizeof(NameInfoResponse));
+        iov[1] = IOVEC_MAKE((void*) host, hl);
+        iov[2] = IOVEC_MAKE((void*) serv, sl);
 
-        mh.msg_iov = iov;
-        mh.msg_iovlen = ELEMENTSOF(iov);
+        mh = (struct msghdr) {
+                .msg_iov = iov,
+                .msg_iovlen = ELEMENTSOF(iov)
+        };
 
         if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0)
                 return -errno;
@@ -332,32 +335,35 @@ static int handle_request(int out_fd, const Packet *packet, size_t length) {
 
         req = &packet->rheader;
 
-        assert(length >= sizeof(RHeader));
-        assert(length == req->length);
+        assert_return(length >= sizeof(RHeader), -EIO);
+        assert_return(length == req->length, -EIO);
 
         switch (req->type) {
 
         case REQUEST_ADDRINFO: {
                const AddrInfoRequest *ai_req = &packet->addrinfo_request;
-               struct addrinfo hints = {}, *result = NULL;
+               struct addrinfo hints, *result = NULL;
                const char *node, *service;
                int ret;
 
-               assert(length >= sizeof(AddrInfoRequest));
-               assert(length == sizeof(AddrInfoRequest) + ai_req->node_len + ai_req->service_len);
+               assert_return(length >= sizeof(AddrInfoRequest), -EBADMSG);
+               assert_return(length == sizeof(AddrInfoRequest) + ai_req->node_len + ai_req->service_len, -EBADMSG);
 
-               hints.ai_flags = ai_req->ai_flags;
-               hints.ai_family = ai_req->ai_family;
-               hints.ai_socktype = ai_req->ai_socktype;
-               hints.ai_protocol = ai_req->ai_protocol;
+               hints = (struct addrinfo) {
+                       .ai_flags = ai_req->ai_flags,
+                       .ai_family = ai_req->ai_family,
+                       .ai_socktype = ai_req->ai_socktype,
+                       .ai_protocol = ai_req->ai_protocol,
+               };
+
+               msan_unpoison(&hints, sizeof(hints));
 
                node = ai_req->node_len ? (const char*) ai_req + sizeof(AddrInfoRequest) : NULL;
                service = ai_req->service_len ? (const char*) ai_req + sizeof(AddrInfoRequest) + ai_req->node_len : NULL;
 
-               ret = getaddrinfo(
-                               node, service,
-                               ai_req->hints_valid ? &hints : NULL,
-                               &result);
+               ret = getaddrinfo(node, service,
+                                 ai_req->hints_valid ? &hints : NULL,
+                                 &result);
 
                /* send_addrinfo_reply() frees result */
                return send_addrinfo_reply(out_fd, req->id, ret, result, errno, h_errno);
@@ -369,21 +375,21 @@ static int handle_request(int out_fd, const Packet *packet, size_t length) {
                union sockaddr_union sa;
                int ret;
 
-               assert(length >= sizeof(NameInfoRequest));
-               assert(length == sizeof(NameInfoRequest) + ni_req->sockaddr_len);
-               assert(sizeof(sa) >= ni_req->sockaddr_len);
+               assert_return(length >= sizeof(NameInfoRequest), -EBADMSG);
+               assert_return(length == sizeof(NameInfoRequest) + ni_req->sockaddr_len, -EBADMSG);
+               assert_return(ni_req->sockaddr_len <= sizeof(sa), -EBADMSG);
 
                memcpy(&sa, (const uint8_t *) ni_req + sizeof(NameInfoRequest), ni_req->sockaddr_len);
 
                ret = getnameinfo(&sa.sa, ni_req->sockaddr_len,
-                               ni_req->gethost ? hostbuf : NULL, ni_req->gethost ? sizeof(hostbuf) : 0,
-                               ni_req->getserv ? servbuf : NULL, ni_req->getserv ? sizeof(servbuf) : 0,
-                               ni_req->flags);
+                                 ni_req->gethost ? hostbuf : NULL, ni_req->gethost ? sizeof(hostbuf) : 0,
+                                 ni_req->getserv ? servbuf : NULL, ni_req->getserv ? sizeof(servbuf) : 0,
+                                 ni_req->flags);
 
                return send_nameinfo_reply(out_fd, req->id, ret,
-                               ret == 0 && ni_req->gethost ? hostbuf : NULL,
-                               ret == 0 && ni_req->getserv ? servbuf : NULL,
-                               errno, h_errno);
+                                          ret == 0 && ni_req->gethost ? hostbuf : NULL,
+                                          ret == 0 && ni_req->getserv ? servbuf : NULL,
+                                          errno, h_errno);
         }
 
         case REQUEST_TERMINATE:
@@ -410,7 +416,7 @@ static void* thread_worker(void *p) {
                 } buf;
                 ssize_t length;
 
-                length = recv(resolve->fds[REQUEST_RECV_FD], &buf, sizeof(buf), 0);
+                length = recv(resolve->fds[REQUEST_RECV_FD], &buf, sizeof buf, 0);
                 if (length < 0) {
                         if (errno == EINTR)
                                 continue;
@@ -420,9 +426,6 @@ static void* thread_worker(void *p) {
                 if (length == 0)
                         break;
 
-                if (resolve->dead)
-                        break;
-
                 if (handle_request(resolve->fds[RESPONSE_SEND_FD], &buf.packet, (size_t) length) < 0)
                         break;
         }
@@ -437,8 +440,7 @@ static int start_threads(sd_resolve *resolve, unsigned extra) {
         unsigned n;
         int r, k;
 
-        if (sigfillset(&ss) < 0)
-                return -errno;
+        assert_se(sigfillset(&ss) >= 0);
 
         /* No signals in forked off threads please. We set the mask before forking, so that the threads never exist
          * with a different mask than a fully blocked one */
@@ -450,7 +452,6 @@ static int start_threads(sd_resolve *resolve, unsigned extra) {
         n = CLAMP(n, WORKERS_MIN, WORKERS_MAX);
 
         while (resolve->n_valid_workers < n) {
-
                 r = pthread_create(&resolve->workers[resolve->n_valid_workers], NULL, thread_worker, resolve);
                 if (r > 0) {
                         r = -r;
@@ -480,8 +481,8 @@ static bool resolve_pid_changed(sd_resolve *r) {
 }
 
 _public_ int sd_resolve_new(sd_resolve **ret) {
-        sd_resolve *resolve = NULL;
-        int i, r;
+        _cleanup_(sd_resolve_unrefp) sd_resolve *resolve = NULL;
+        int i;
 
         assert_return(ret, -EINVAL);
 
@@ -495,35 +496,27 @@ _public_ int sd_resolve_new(sd_resolve **ret) {
         for (i = 0; i < _FD_MAX; i++)
                 resolve->fds[i] = -1;
 
-        r = socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD);
-        if (r < 0) {
-                r = -errno;
-                goto fail;
-        }
+        if (socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD) < 0)
+                return -errno;
 
-        r = socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + RESPONSE_RECV_FD);
-        if (r < 0) {
-                r = -errno;
-                goto fail;
-        }
+        if (socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + RESPONSE_RECV_FD) < 0)
+                return -errno;
 
-        fd_inc_sndbuf(resolve->fds[REQUEST_SEND_FD], QUERIES_MAX * BUFSIZE);
-        fd_inc_rcvbuf(resolve->fds[REQUEST_RECV_FD], QUERIES_MAX * BUFSIZE);
-        fd_inc_sndbuf(resolve->fds[RESPONSE_SEND_FD], QUERIES_MAX * BUFSIZE);
-        fd_inc_rcvbuf(resolve->fds[RESPONSE_RECV_FD], QUERIES_MAX * BUFSIZE);
+        for (i = 0; i < _FD_MAX; i++)
+                resolve->fds[i] = fd_move_above_stdio(resolve->fds[i]);
 
-        fd_nonblock(resolve->fds[RESPONSE_RECV_FD], true);
+        (void) fd_inc_sndbuf(resolve->fds[REQUEST_SEND_FD], QUERIES_MAX * BUFSIZE);
+        (void) fd_inc_rcvbuf(resolve->fds[REQUEST_RECV_FD], QUERIES_MAX * BUFSIZE);
+        (void) fd_inc_sndbuf(resolve->fds[RESPONSE_SEND_FD], QUERIES_MAX * BUFSIZE);
+        (void) fd_inc_rcvbuf(resolve->fds[RESPONSE_RECV_FD], QUERIES_MAX * BUFSIZE);
 
-        *ret = resolve;
-        return 0;
+        (void) fd_nonblock(resolve->fds[RESPONSE_RECV_FD], true);
 
-fail:
-        sd_resolve_unref(resolve);
-        return r;
+        *ret = TAKE_PTR(resolve);
+        return 0;
 }
 
 _public_ int sd_resolve_default(sd_resolve **ret) {
-
         static thread_local sd_resolve *default_resolve = NULL;
         sd_resolve *e = NULL;
         int r;
@@ -564,7 +557,7 @@ _public_ int sd_resolve_get_tid(sd_resolve *resolve, pid_t *tid) {
         return -ENXIO;
 }
 
-static void resolve_free(sd_resolve *resolve) {
+static sd_resolve *resolve_free(sd_resolve *resolve) {
         PROTECT_ERRNO;
         sd_resolve_query *q;
         unsigned i;
@@ -588,7 +581,7 @@ static void resolve_free(sd_resolve *resolve) {
 
                 RHeader req = {
                         .type = REQUEST_TERMINATE,
-                        .length = sizeof(req)
+                        .length = sizeof req,
                 };
 
                 /* Send one termination packet for each worker */
@@ -603,31 +596,11 @@ static void resolve_free(sd_resolve *resolve) {
 
         /* Close all communication channels */
         close_many(resolve->fds, _FD_MAX);
-        free(resolve);
-}
-
-_public_ sd_resolve* sd_resolve_ref(sd_resolve *resolve) {
-        assert_return(resolve, NULL);
 
-        assert(resolve->n_ref >= 1);
-        resolve->n_ref++;
-
-        return resolve;
+        return mfree(resolve);
 }
 
-_public_ sd_resolve* sd_resolve_unref(sd_resolve *resolve) {
-
-        if (!resolve)
-                return NULL;
-
-        assert(resolve->n_ref >= 1);
-        resolve->n_ref--;
-
-        if (resolve->n_ref <= 0)
-                resolve_free(resolve);
-
-        return NULL;
-}
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_resolve, sd_resolve, resolve_free);
 
 _public_ int sd_resolve_get_fd(sd_resolve *resolve) {
         assert_return(resolve, -EINVAL);
@@ -705,8 +678,8 @@ static int complete_query(sd_resolve *resolve, sd_resolve_query *q) {
 
 static int unserialize_addrinfo(const void **p, size_t *length, struct addrinfo **ret_ai) {
         AddrInfoSerialization s;
-        size_t l;
         struct addrinfo *ai;
+        size_t l;
 
         assert(p);
         assert(*p);
@@ -722,15 +695,17 @@ static int unserialize_addrinfo(const void **p, size_t *length, struct addrinfo
         if (*length < l)
                 return -EBADMSG;
 
-        ai = new0(struct addrinfo, 1);
+        ai = new(struct addrinfo, 1);
         if (!ai)
                 return -ENOMEM;
 
-        ai->ai_flags = s.ai_flags;
-        ai->ai_family = s.ai_family;
-        ai->ai_socktype = s.ai_socktype;
-        ai->ai_protocol = s.ai_protocol;
-        ai->ai_addrlen = s.ai_addrlen;
+        *ai = (struct addrinfo) {
+                .ai_flags = s.ai_flags,
+                .ai_family = s.ai_family,
+                .ai_socktype = s.ai_socktype,
+                .ai_protocol = s.ai_protocol,
+                .ai_addrlen = s.ai_addrlen,
+        };
 
         if (s.ai_addrlen > 0) {
                 ai->ai_addr = memdup((const uint8_t*) *p + sizeof(AddrInfoSerialization), s.ai_addrlen);
@@ -762,11 +737,11 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len
         int r;
 
         assert(resolve);
+        assert(packet);
 
         resp = &packet->rheader;
-        assert(resp);
-        assert(length >= sizeof(RHeader));
-        assert(length == resp->length);
+        assert_return(length >= sizeof(RHeader), -EIO);
+        assert_return(length == resp->length, -EIO);
 
         if (resp->type == RESPONSE_DIED) {
                 resolve->dead = true;
@@ -788,12 +763,10 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len
                 size_t l;
                 struct addrinfo *prev = NULL;
 
-                assert(length >= sizeof(AddrInfoResponse));
-                assert(q->type == REQUEST_ADDRINFO);
+                assert_return(length >= sizeof(AddrInfoResponse), -EBADMSG);
+                assert_return(q->type == REQUEST_ADDRINFO, -EBADMSG);
 
-                q->ret = ai_resp->ret;
-                q->_errno = ai_resp->_errno;
-                q->_h_errno = ai_resp->_h_errno;
+                query_assign_errno(q, ai_resp->ret, ai_resp->_errno, ai_resp->_h_errno);
 
                 l = length - sizeof(AddrInfoResponse);
                 p = (const uint8_t*) resp + sizeof(AddrInfoResponse);
@@ -803,9 +776,7 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len
 
                         r = unserialize_addrinfo(&p, &l, &ai);
                         if (r < 0) {
-                                q->ret = EAI_SYSTEM;
-                                q->_errno = -r;
-                                q->_h_errno = 0;
+                                query_assign_errno(q, EAI_SYSTEM, r, 0);
                                 freeaddrinfo(q->addrinfo);
                                 q->addrinfo = NULL;
                                 break;
@@ -825,39 +796,28 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len
         case RESPONSE_NAMEINFO: {
                 const NameInfoResponse *ni_resp = &packet->nameinfo_response;
 
-                assert(length >= sizeof(NameInfoResponse));
-                assert(q->type == REQUEST_NAMEINFO);
+                assert_return(length >= sizeof(NameInfoResponse), -EBADMSG);
+                assert_return(q->type == REQUEST_NAMEINFO, -EBADMSG);
 
                 if (ni_resp->hostlen > DNS_HOSTNAME_MAX ||
                     ni_resp->servlen > DNS_HOSTNAME_MAX ||
-                    sizeof(NameInfoResponse) + ni_resp->hostlen + ni_resp->servlen > length + 2) {
-                        q->ret = EAI_SYSTEM;
-                        q->_errno = -EIO;
-                        q->_h_errno = 0;
-
-                } else {
-                        q->ret = ni_resp->ret;
-                        q->_errno = ni_resp->_errno;
-                        q->_h_errno = ni_resp->_h_errno;
+                    sizeof(NameInfoResponse) + ni_resp->hostlen + ni_resp->servlen > length)
+                        query_assign_errno(q, EAI_SYSTEM, EIO, 0);
+                else {
+                        query_assign_errno(q, ni_resp->ret, ni_resp->_errno, ni_resp->_h_errno);
 
                         if (ni_resp->hostlen > 0) {
                                 q->host = strndup((const char*) ni_resp + sizeof(NameInfoResponse),
                                                   ni_resp->hostlen-1);
-                                if (!q->host) {
-                                        q->ret = EAI_MEMORY;
-                                        q->_errno = ENOMEM;
-                                        q->_h_errno = 0;
-                                }
+                                if (!q->host)
+                                        query_assign_errno(q, EAI_MEMORY, ENOMEM, 0);
                         }
 
                         if (ni_resp->servlen > 0) {
                                 q->serv = strndup((const char*) ni_resp + sizeof(NameInfoResponse) + ni_resp->hostlen,
                                                   ni_resp->servlen-1);
-                                if (!q->serv) {
-                                        q->ret = EAI_MEMORY;
-                                        q->_errno = ENOMEM;
-                                        q->_h_errno = 0;
-                                }
+                                if (!q->serv)
+                                        query_assign_errno(q, EAI_MEMORY, ENOMEM, 0);
                         }
                 }
 
@@ -885,7 +845,7 @@ _public_ int sd_resolve_process(sd_resolve *resolve) {
         /* We don't allow recursively invoking sd_resolve_process(). */
         assert_return(!resolve->current, -EBUSY);
 
-        l = recv(resolve->fds[RESPONSE_RECV_FD], &buf, sizeof(buf), 0);
+        l = recv(resolve->fds[RESPONSE_RECV_FD], &buf, sizeof buf, 0);
         if (l < 0) {
                 if (errno == EAGAIN)
                         return 0;
@@ -959,17 +919,20 @@ static int alloc_query(sd_resolve *resolve, bool floating, sd_resolve_query **_q
         return 0;
 }
 
-_public_ int sd_resolve_getaddrinfo(
+int resolve_getaddrinfo_with_destroy_callback(
                 sd_resolve *resolve,
-                sd_resolve_query **_q,
+                sd_resolve_query **ret_query,
                 const char *node, const char *service,
                 const struct addrinfo *hints,
-                sd_resolve_getaddrinfo_handler_t callback, void *userdata) {
+                sd_resolve_getaddrinfo_handler_t callback,
+                sd_resolve_destroy_t destroy_callback,
+                void *userdata) {
 
+        _cleanup_(sd_resolve_query_unrefp) sd_resolve_query *q = NULL;
+        size_t node_len, service_len;
         AddrInfoRequest req = {};
-        struct msghdr mh = {};
         struct iovec iov[3];
-        sd_resolve_query *q;
+        struct msghdr mh = {};
         int r;
 
         assert_return(resolve, -EINVAL);
@@ -977,7 +940,7 @@ _public_ int sd_resolve_getaddrinfo(
         assert_return(callback, -EINVAL);
         assert_return(!resolve_pid_changed(resolve), -ECHILD);
 
-        r = alloc_query(resolve, !_q, &q);
+        r = alloc_query(resolve, !ret_query, &q);
         if (r < 0)
                 return r;
 
@@ -985,41 +948,58 @@ _public_ int sd_resolve_getaddrinfo(
         q->getaddrinfo_handler = callback;
         q->userdata = userdata;
 
-        req.node_len = node ? strlen(node)+1 : 0;
-        req.service_len = service ? strlen(service)+1 : 0;
+        node_len = node ? strlen(node) + 1 : 0;
+        service_len = service ? strlen(service) + 1 : 0;
 
-        req.header.id = q->id;
-        req.header.type = REQUEST_ADDRINFO;
-        req.header.length = sizeof(AddrInfoRequest) + req.node_len + req.service_len;
+        req = (AddrInfoRequest) {
+                .node_len = node_len,
+                .service_len = service_len,
 
-        if (hints) {
-                req.hints_valid = true;
-                req.ai_flags = hints->ai_flags;
-                req.ai_family = hints->ai_family;
-                req.ai_socktype = hints->ai_socktype;
-                req.ai_protocol = hints->ai_protocol;
-        }
+                .header.id = q->id,
+                .header.type = REQUEST_ADDRINFO,
+                .header.length = sizeof(AddrInfoRequest) + node_len + service_len,
 
-        iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(AddrInfoRequest) };
+                .hints_valid = hints,
+                .ai_flags = hints ? hints->ai_flags : 0,
+                .ai_family = hints ? hints->ai_family : 0,
+                .ai_socktype = hints ? hints->ai_socktype : 0,
+                .ai_protocol = hints ? hints->ai_protocol : 0,
+        };
+
+        msan_unpoison(&req, sizeof(req));
+
+        iov[mh.msg_iovlen++] = IOVEC_MAKE(&req, sizeof(AddrInfoRequest));
         if (node)
-                iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) node, .iov_len = req.node_len };
+                iov[mh.msg_iovlen++] = IOVEC_MAKE((void*) node, req.node_len);
         if (service)
-                iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) service, .iov_len = req.service_len };
+                iov[mh.msg_iovlen++] = IOVEC_MAKE((void*) service, req.service_len);
         mh.msg_iov = iov;
 
-        if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) {
-                sd_resolve_query_unref(q);
+        if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0)
                 return -errno;
-        }
 
         resolve->n_outstanding++;
+        q->destroy_callback = destroy_callback;
 
-        if (_q)
-                *_q = q;
+        if (ret_query)
+                *ret_query = q;
+
+        TAKE_PTR(q);
 
         return 0;
 }
 
+_public_ int sd_resolve_getaddrinfo(
+                sd_resolve *resolve,
+                sd_resolve_query **ret_query,
+                const char *node, const char *service,
+                const struct addrinfo *hints,
+                sd_resolve_getaddrinfo_handler_t callback,
+                void *userdata) {
+
+        return resolve_getaddrinfo_with_destroy_callback(resolve, ret_query, node, service, hints, callback, NULL, userdata);
+}
+
 static int getaddrinfo_done(sd_resolve_query* q) {
         assert(q);
         assert(q->done);
@@ -1031,19 +1011,20 @@ static int getaddrinfo_done(sd_resolve_query* q) {
         return q->getaddrinfo_handler(q, q->ret, q->addrinfo, q->userdata);
 }
 
-_public_ int sd_resolve_getnameinfo(
+int resolve_getnameinfo_with_destroy_callback(
                 sd_resolve *resolve,
-                sd_resolve_query**_q,
+                sd_resolve_query **ret_query,
                 const struct sockaddr *sa, socklen_t salen,
                 int flags,
                 uint64_t get,
                 sd_resolve_getnameinfo_handler_t callback,
+                sd_resolve_destroy_t destroy_callback,
                 void *userdata) {
 
+        _cleanup_(sd_resolve_query_unrefp) sd_resolve_query *q = NULL;
         NameInfoRequest req = {};
-        struct msghdr mh = {};
         struct iovec iov[2];
-        sd_resolve_query *q;
+        struct msghdr mh;
         int r;
 
         assert_return(resolve, -EINVAL);
@@ -1054,7 +1035,7 @@ _public_ int sd_resolve_getnameinfo(
         assert_return(callback, -EINVAL);
         assert_return(!resolve_pid_changed(resolve), -ECHILD);
 
-        r = alloc_query(resolve, !_q, &q);
+        r = alloc_query(resolve, !ret_query, &q);
         if (r < 0)
                 return r;
 
@@ -1062,34 +1043,53 @@ _public_ int sd_resolve_getnameinfo(
         q->getnameinfo_handler = callback;
         q->userdata = userdata;
 
-        req.header.id = q->id;
-        req.header.type = REQUEST_NAMEINFO;
-        req.header.length = sizeof(NameInfoRequest) + salen;
+        req = (NameInfoRequest) {
+                .header.id = q->id,
+                .header.type = REQUEST_NAMEINFO,
+                .header.length = sizeof(NameInfoRequest) + salen,
 
-        req.flags = flags;
-        req.sockaddr_len = salen;
-        req.gethost = !!(get & SD_RESOLVE_GET_HOST);
-        req.getserv = !!(get & SD_RESOLVE_GET_SERVICE);
+                .flags = flags,
+                .sockaddr_len = salen,
+                .gethost = !!(get & SD_RESOLVE_GET_HOST),
+                .getserv = !!(get & SD_RESOLVE_GET_SERVICE),
+        };
 
-        iov[0] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(NameInfoRequest) };
-        iov[1] = (struct iovec) { .iov_base = (void*) sa, .iov_len = salen };
+        msan_unpoison(&req, sizeof(req));
 
-        mh.msg_iov = iov;
-        mh.msg_iovlen = 2;
+        iov[0] = IOVEC_MAKE(&req, sizeof(NameInfoRequest));
+        iov[1] = IOVEC_MAKE((void*) sa, salen);
 
-        if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) {
-                sd_resolve_query_unref(q);
+        mh = (struct msghdr) {
+                .msg_iov = iov,
+                .msg_iovlen = ELEMENTSOF(iov)
+        };
+
+        if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0)
                 return -errno;
-        }
 
         resolve->n_outstanding++;
+        q->destroy_callback = destroy_callback;
 
-        if (_q)
-                *_q = q;
+        if (ret_query)
+                *ret_query = q;
+
+        TAKE_PTR(q);
 
         return 0;
 }
 
+_public_ int sd_resolve_getnameinfo(
+                sd_resolve *resolve,
+                sd_resolve_query **ret_query,
+                const struct sockaddr *sa, socklen_t salen,
+                int flags,
+                uint64_t get,
+                sd_resolve_getnameinfo_handler_t callback,
+                void *userdata) {
+
+        return resolve_getnameinfo_with_destroy_callback(resolve, ret_query, sa, salen, flags, get, callback, NULL, userdata);
+}
+
 static int getnameinfo_done(sd_resolve_query *q) {
 
         assert(q);
@@ -1097,20 +1097,11 @@ static int getnameinfo_done(sd_resolve_query *q) {
         assert(q->getnameinfo_handler);
 
         errno = q->_errno;
-        h_errno= q->_h_errno;
+        h_errno = q->_h_errno;
 
         return q->getnameinfo_handler(q, q->ret, q->host, q->serv, q->userdata);
 }
 
-_public_ sd_resolve_query* sd_resolve_query_ref(sd_resolve_query *q) {
-        assert_return(q, NULL);
-
-        assert(q->n_ref >= 1);
-        q->n_ref++;
-
-        return q;
-}
-
 static void resolve_freeaddrinfo(struct addrinfo *ai) {
         while (ai) {
                 struct addrinfo *next = ai->ai_next;
@@ -1150,30 +1141,23 @@ static void resolve_query_disconnect(sd_resolve_query *q) {
                 sd_resolve_unref(resolve);
 }
 
-static void resolve_query_free(sd_resolve_query *q) {
+static sd_resolve_query *resolve_query_free(sd_resolve_query *q) {
         assert(q);
 
         resolve_query_disconnect(q);
 
+        if (q->destroy_callback)
+                q->destroy_callback(q->userdata);
+
         resolve_freeaddrinfo(q->addrinfo);
         free(q->host);
         free(q->serv);
-        free(q);
-}
-
-_public_ sd_resolve_query* sd_resolve_query_unref(sd_resolve_query* q) {
-        if (!q)
-                return NULL;
 
-        assert(q->n_ref >= 1);
-        q->n_ref--;
-
-        if (q->n_ref <= 0)
-                resolve_query_free(q);
-
-        return NULL;
+        return mfree(q);
 }
 
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_resolve_query, sd_resolve_query, resolve_query_free);
+
 _public_ int sd_resolve_query_is_done(sd_resolve_query *q) {
         assert_return(q, -EINVAL);
         assert_return(!resolve_pid_changed(q->resolve), -ECHILD);
@@ -1207,6 +1191,50 @@ _public_ sd_resolve *sd_resolve_query_get_resolve(sd_resolve_query *q) {
         return q->resolve;
 }
 
+_public_ int sd_resolve_query_get_destroy_callback(sd_resolve_query *q, sd_resolve_destroy_t *destroy_callback) {
+        assert_return(q, -EINVAL);
+
+        if (destroy_callback)
+                *destroy_callback = q->destroy_callback;
+
+        return !!q->destroy_callback;
+}
+
+_public_ int sd_resolve_query_set_destroy_callback(sd_resolve_query *q, sd_resolve_destroy_t destroy_callback) {
+        assert_return(q, -EINVAL);
+
+        q->destroy_callback = destroy_callback;
+        return 0;
+}
+
+_public_ int sd_resolve_query_get_floating(sd_resolve_query *q) {
+        assert_return(q, -EINVAL);
+
+        return q->floating;
+}
+
+_public_ int sd_resolve_query_set_floating(sd_resolve_query *q, int b) {
+        assert_return(q, -EINVAL);
+
+        if (q->floating == !!b)
+                return 0;
+
+        if (!q->resolve) /* Already disconnected */
+                return -ESTALE;
+
+        q->floating = b;
+
+        if (b) {
+                sd_resolve_query_ref(q);
+                sd_resolve_unref(q->resolve);
+        } else {
+                sd_resolve_ref(q->resolve);
+                sd_resolve_query_unref(q);
+        }
+
+        return 1;
+}
+
 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         sd_resolve *resolve = userdata;
         int r;