1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2013 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #ifdef HAVE_VALGRIND_MEMCHECK_H
23 #include <valgrind/memcheck.h>
30 #include <sys/prctl.h>
34 #include "memfd-util.h"
36 #include "bus-internal.h"
37 #include "bus-message.h"
38 #include "bus-kernel.h"
39 #include "bus-bloom.h"
41 #include "bus-label.h"
42 #include "cgroup-util.h"
44 #define UNIQUE_NAME_MAX (3+DECIMAL_STR_MAX(uint64_t))
46 int bus_kernel_parse_unique_name(const char *s, uint64_t *id) {
52 if (!startswith(s, ":1."))
55 r = safe_atou64(s + 3, id);
62 static void append_payload_vec(struct kdbus_item **d, const void *p, size_t sz) {
68 /* Note that p can be NULL, which encodes a region full of
69 * zeroes, which is useful to optimize certain padding
72 (*d)->size = offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec);
73 (*d)->type = KDBUS_ITEM_PAYLOAD_VEC;
74 (*d)->vec.address = PTR_TO_UINT64(p);
77 *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
80 static void append_payload_memfd(struct kdbus_item **d, int memfd, size_t sz) {
86 (*d)->size = offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd);
87 (*d)->type = KDBUS_ITEM_PAYLOAD_MEMFD;
88 (*d)->memfd.fd = memfd;
89 (*d)->memfd.size = sz;
91 *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
94 static void append_destination(struct kdbus_item **d, const char *s, size_t length) {
100 (*d)->size = offsetof(struct kdbus_item, str) + length + 1;
101 (*d)->type = KDBUS_ITEM_DST_NAME;
102 memcpy((*d)->str, s, length + 1);
104 *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
107 static struct kdbus_bloom_filter *append_bloom(struct kdbus_item **d, size_t length) {
108 struct kdbus_item *i;
114 i->size = offsetof(struct kdbus_item, bloom_filter) +
115 offsetof(struct kdbus_bloom_filter, data) +
117 i->type = KDBUS_ITEM_BLOOM_FILTER;
119 *d = (struct kdbus_item *) ((uint8_t*) i + i->size);
121 return &i->bloom_filter;
124 static void append_fds(struct kdbus_item **d, const int fds[], unsigned n_fds) {
130 (*d)->size = offsetof(struct kdbus_item, fds) + sizeof(int) * n_fds;
131 (*d)->type = KDBUS_ITEM_FDS;
132 memcpy((*d)->fds, fds, sizeof(int) * n_fds);
134 *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size);
137 static int bus_message_setup_bloom(sd_bus_message *m, struct kdbus_bloom_filter *bloom) {
146 memzero(data, m->bus->bloom_size);
147 bloom->generation = 0;
149 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "message-type", bus_message_type_to_string(m->header->type));
152 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "interface", m->interface);
154 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "member", m->member);
156 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path", m->path);
157 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path-slash-prefix", m->path);
158 bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path-slash-prefix", m->path, '/');
161 r = sd_bus_message_rewind(m, true);
165 for (i = 0; i < 64; i++) {
168 char buf[sizeof("arg")-1 + 2 + sizeof("-slash-prefix")];
171 r = sd_bus_message_peek_type(m, &type, NULL);
175 if (type != SD_BUS_TYPE_STRING &&
176 type != SD_BUS_TYPE_OBJECT_PATH &&
177 type != SD_BUS_TYPE_SIGNATURE)
180 r = sd_bus_message_read_basic(m, type, &t);
184 e = stpcpy(buf, "arg");
186 *(e++) = '0' + (char) i;
188 *(e++) = '0' + (char) (i / 10);
189 *(e++) = '0' + (char) (i % 10);
193 bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t);
195 strcpy(e, "-dot-prefix");
196 bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t, '.');
197 strcpy(e, "-slash-prefix");
198 bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t, '/');
204 static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
205 struct bus_body_part *part;
206 struct kdbus_item *d;
207 const char *destination;
218 /* We put this together only once, if this message is reused
219 * we reuse the earlier-built version */
223 destination = m->destination ?: m->destination_ptr;
226 r = bus_kernel_parse_unique_name(destination, &unique);
234 sz = offsetof(struct kdbus_msg, items);
236 assert_cc(ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec)) ==
237 ALIGN8(offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd)));
239 /* Add in fixed header, fields header and payload */
240 sz += (1 + m->n_body_parts) *
241 ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec));
243 /* Add space for bloom filter */
244 sz += ALIGN8(offsetof(struct kdbus_item, bloom_filter) +
245 offsetof(struct kdbus_bloom_filter, data) +
248 /* Add in well-known destination header */
250 dl = strlen(destination);
251 sz += ALIGN8(offsetof(struct kdbus_item, str) + dl + 1);
254 /* Add space for unix fds */
256 sz += ALIGN8(offsetof(struct kdbus_item, fds) + sizeof(int)*m->n_fds);
258 m->kdbus = memalign(8, sz);
264 m->free_kdbus = true;
265 memzero(m->kdbus, sz);
268 ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
269 ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);
272 /* verify_destination_id will usually be 0, which makes the kernel driver only look
273 * at the provided well-known name. Otherwise, the kernel will make sure the provided
274 * destination id matches the owner of the provided weel-known-name, and fail if they
275 * differ. Currently, this is only needed for bus-proxyd. */
276 m->kdbus->dst_id = m->verify_destination_id;
278 m->kdbus->dst_id = destination ? unique : KDBUS_DST_ID_BROADCAST;
281 m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
282 m->kdbus->cookie = (uint64_t) m->header->serial;
283 m->kdbus->priority = m->priority;
285 if (m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) {
286 m->kdbus->cookie_reply = m->reply_cookie;
290 assert_se(clock_gettime(CLOCK_MONOTONIC_COARSE, &now) == 0);
291 m->kdbus->timeout_ns = now.tv_sec * NSEC_PER_SEC + now.tv_nsec +
292 m->timeout * NSEC_PER_USEC;
298 append_destination(&d, destination, dl);
300 append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
302 MESSAGE_FOREACH_PART(part, i, m) {
304 /* If this is padding then simply send a
305 * vector with a NULL data pointer which the
306 * kernel will just pass through. This is the
307 * most efficient way to encode zeroes */
309 append_payload_vec(&d, NULL, part->size);
313 if (part->memfd >= 0 && part->sealed && destination) {
314 /* Try to send a memfd, if the part is
315 * sealed and this is not a broadcast. Since we can only */
317 append_payload_memfd(&d, part->memfd, part->size);
321 /* Otherwise, let's send a vector to the actual data.
322 * For that, we need to map it first. */
323 r = bus_body_part_map(part);
327 append_payload_vec(&d, part->data, part->size);
330 if (m->kdbus->dst_id == KDBUS_DST_ID_BROADCAST) {
331 struct kdbus_bloom_filter *bloom;
333 bloom = append_bloom(&d, m->bus->bloom_size);
334 r = bus_message_setup_bloom(m, bloom);
340 append_fds(&d, m->fds, m->n_fds);
342 m->kdbus->size = (uint8_t*) d - (uint8_t*) m->kdbus;
343 assert(m->kdbus->size <= sz);
352 static void unset_memfds(struct sd_bus_message *m) {
353 struct bus_body_part *part;
358 /* Make sure the memfds are not freed twice */
359 MESSAGE_FOREACH_PART(part, i, m)
360 if (part->memfd >= 0)
364 static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
365 sd_bus_message *m = NULL;
366 struct kdbus_item *d;
368 _cleanup_free_ int *fds = NULL;
369 struct bus_header *h = NULL;
370 size_t total, n_bytes = 0, idx = 0;
371 const char *destination = NULL, *seclabel = NULL;
376 assert(k->payload_type == KDBUS_PAYLOAD_DBUS);
378 KDBUS_ITEM_FOREACH(d, k, items) {
381 l = d->size - offsetof(struct kdbus_item, data);
385 case KDBUS_ITEM_PAYLOAD_OFF:
387 h = (struct bus_header *)((uint8_t *)k + d->vec.offset);
389 if (!bus_header_is_complete(h, d->vec.size))
393 n_bytes += d->vec.size;
396 case KDBUS_ITEM_PAYLOAD_MEMFD:
400 n_bytes += d->memfd.size;
403 case KDBUS_ITEM_FDS: {
408 f = realloc(fds, sizeof(int) * (n_fds + j));
413 memcpy(fds + n_fds, d->fds, sizeof(int) * j);
418 case KDBUS_ITEM_SECLABEL:
427 r = bus_header_message_size(h, &total);
431 if (n_bytes != total)
434 /* on kdbus we only speak native endian gvariant, never dbus1
435 * marshalling or reverse endian */
436 if (h->version != 2 ||
437 h->endian != BUS_NATIVE_ENDIAN)
440 r = bus_message_from_header(bus, h, sizeof(struct bus_header), fds, n_fds, NULL, seclabel, 0, &m);
444 /* The well-known names list is different from the other
445 credentials. If we asked for it, but nothing is there, this
446 means that the list of well-known names is simply empty, not
447 that we lack any data */
449 m->creds.mask |= (SD_BUS_CREDS_UNIQUE_NAME|SD_BUS_CREDS_WELL_KNOWN_NAMES) & bus->creds_mask;
451 KDBUS_ITEM_FOREACH(d, k, items) {
454 l = d->size - offsetof(struct kdbus_item, data);
458 case KDBUS_ITEM_PAYLOAD_OFF: {
461 begin_body = BUS_MESSAGE_BODY_BEGIN(m);
463 if (idx + d->vec.size > begin_body) {
464 struct bus_body_part *part;
466 /* Contains body material */
468 part = message_append_part(m);
474 /* A -1 offset is NUL padding. */
475 part->is_zero = d->vec.offset == ~0ULL;
477 if (idx >= begin_body) {
479 part->data = (uint8_t *)k + d->vec.offset;
480 part->size = d->vec.size;
483 part->data = (uint8_t *)k + d->vec.offset + (begin_body - idx);
484 part->size = d->vec.size - (begin_body - idx);
494 case KDBUS_ITEM_PAYLOAD_MEMFD: {
495 struct bus_body_part *part;
497 if (idx < BUS_MESSAGE_BODY_BEGIN(m)) {
502 part = message_append_part(m);
508 part->memfd = d->memfd.fd;
509 part->size = d->memfd.size;
512 idx += d->memfd.size;
516 case KDBUS_ITEM_PIDS:
518 /* The PID starttime/TID might be missing,
519 * when the data is faked by some data bus
520 * proxy and it lacks that information about
521 * the real client since SO_PEERCRED is used
524 if (d->pids.pid > 0) {
525 m->creds.pid = (pid_t) d->pids.pid;
526 m->creds.mask |= SD_BUS_CREDS_PID & bus->creds_mask;
529 if (d->pids.starttime > 0) {
530 m->creds.pid_starttime = d->pids.starttime / NSEC_PER_USEC;
531 m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask;
534 if (d->pids.tid > 0) {
535 m->creds.tid = (pid_t) d->pids.tid;
536 m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask;
541 case KDBUS_ITEM_CREDS:
543 /* EUID/SUID/FSUID/EGID/SGID/FSGID might be missing too (see above). */
545 if ((uid_t) d->creds.uid != (uid_t) -1) {
546 m->creds.uid = (uid_t) d->creds.uid;
547 m->creds.mask |= SD_BUS_CREDS_UID & bus->creds_mask;
550 if ((uid_t) d->creds.euid != (uid_t) -1) {
551 m->creds.euid = (uid_t) d->creds.euid;
552 m->creds.mask |= SD_BUS_CREDS_EUID & bus->creds_mask;
555 if ((uid_t) d->creds.suid != (uid_t) -1) {
556 m->creds.suid = (uid_t) d->creds.suid;
557 m->creds.mask |= SD_BUS_CREDS_SUID & bus->creds_mask;
560 if ((uid_t) d->creds.fsuid != (uid_t) -1) {
561 m->creds.fsuid = (uid_t) d->creds.fsuid;
562 m->creds.mask |= SD_BUS_CREDS_FSUID & bus->creds_mask;
565 if ((gid_t) d->creds.gid != (gid_t) -1) {
566 m->creds.gid = (gid_t) d->creds.gid;
567 m->creds.mask |= SD_BUS_CREDS_GID & bus->creds_mask;
570 if ((gid_t) d->creds.egid != (gid_t) -1) {
571 m->creds.egid = (gid_t) d->creds.egid;
572 m->creds.mask |= SD_BUS_CREDS_EGID & bus->creds_mask;
575 if ((gid_t) d->creds.sgid != (gid_t) -1) {
576 m->creds.sgid = (gid_t) d->creds.sgid;
577 m->creds.mask |= SD_BUS_CREDS_SGID & bus->creds_mask;
580 if ((gid_t) d->creds.fsgid != (gid_t) -1) {
581 m->creds.fsgid = (gid_t) d->creds.fsgid;
582 m->creds.mask |= SD_BUS_CREDS_FSGID & bus->creds_mask;
587 case KDBUS_ITEM_TIMESTAMP:
589 if (bus->attach_flags & KDBUS_ATTACH_TIMESTAMP) {
590 m->realtime = d->timestamp.realtime_ns / NSEC_PER_USEC;
591 m->monotonic = d->timestamp.monotonic_ns / NSEC_PER_USEC;
592 m->seqnum = d->timestamp.seqnum;
597 case KDBUS_ITEM_PID_COMM:
598 m->creds.comm = d->str;
599 m->creds.mask |= SD_BUS_CREDS_COMM & bus->creds_mask;
602 case KDBUS_ITEM_TID_COMM:
603 m->creds.tid_comm = d->str;
604 m->creds.mask |= SD_BUS_CREDS_TID_COMM & bus->creds_mask;
608 m->creds.exe = d->str;
609 m->creds.mask |= SD_BUS_CREDS_EXE & bus->creds_mask;
612 case KDBUS_ITEM_CMDLINE:
613 m->creds.cmdline = d->str;
614 m->creds.cmdline_size = l;
615 m->creds.mask |= SD_BUS_CREDS_CMDLINE & bus->creds_mask;
618 case KDBUS_ITEM_CGROUP:
619 m->creds.cgroup = d->str;
620 m->creds.mask |= (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID) & bus->creds_mask;
622 r = bus_get_root_path(bus);
626 m->creds.cgroup_root = bus->cgroup_root;
630 case KDBUS_ITEM_AUDIT:
631 if ((uint32_t) d->audit.sessionid != (uint32_t) -1) {
632 m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
633 m->creds.mask |= SD_BUS_CREDS_AUDIT_SESSION_ID & bus->creds_mask;
636 if ((uid_t) d->audit.loginuid != (uid_t) -1) {
637 m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
638 m->creds.mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID & bus->creds_mask;
642 case KDBUS_ITEM_CAPS:
643 m->creds.capability = (uint8_t *) d->caps.caps;
644 m->creds.capability_size = d->size - offsetof(struct kdbus_item, caps.caps);
645 m->creds.mask |= (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS) & bus->creds_mask;
648 case KDBUS_ITEM_DST_NAME:
649 if (!service_name_is_valid(d->str)) {
654 destination = d->str;
657 case KDBUS_ITEM_OWNED_NAME:
658 if (!service_name_is_valid(d->name.name)) {
663 if (bus->creds_mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) {
664 r = strv_extend(&m->creds.well_known_names, d->name.name);
668 m->creds.mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES;
672 case KDBUS_ITEM_CONN_DESCRIPTION:
673 m->creds.description = d->str;
674 m->creds.mask |= SD_BUS_CREDS_DESCRIPTION & bus->creds_mask;
677 case KDBUS_ITEM_AUXGROUPS:
679 if (bus->creds_mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS) {
682 n = (d->size - offsetof(struct kdbus_item, data64)) / sizeof(uint64_t);
689 for (i = 0; i < n; i++)
690 u[i] = (uid_t) d->data64[i];
692 m->creds.supplementary_gids = u;
693 m->creds.n_supplementary_gids = n;
695 m->creds.mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS;
701 case KDBUS_ITEM_SECLABEL:
705 log_debug("Got unknown field from kernel %llu", d->type);
709 r = bus_message_parse_fields(m);
713 /* Override information from the user header with data from the kernel */
714 if (k->src_id == KDBUS_SRC_ID_KERNEL)
715 m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus";
717 snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id);
718 m->sender = m->creds.unique_name = m->sender_buffer;
722 m->destination = destination;
723 else if (k->dst_id == KDBUS_DST_ID_BROADCAST)
724 m->destination = NULL;
725 else if (k->dst_id == KDBUS_DST_ID_NAME)
726 m->destination = bus->unique_name; /* fill in unique name if the well-known name is missing */
728 snprintf(m->destination_buffer, sizeof(m->destination_buffer), ":1.%llu", (unsigned long long) k->dst_id);
729 m->destination = m->destination_buffer;
732 /* We take possession of the kmsg struct now */
734 m->release_kdbus = true;
738 bus->rqueue[bus->rqueue_size++] = m;
744 sd_bus_message_unref(m);
749 int bus_kernel_take_fd(sd_bus *b) {
750 struct kdbus_cmd_hello *hello;
751 struct kdbus_item *item;
752 _cleanup_free_ char *g = NULL;
754 size_t l = 0, m = 0, sz;
764 if (b->description) {
765 g = bus_label_escape(b->description);
773 /* If no name is explicitly set, we'll include a hint
774 * indicating the library implementation, a hint which
775 * kind of bus this is and the thread name */
777 assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0);
780 name = b->is_system ? "sd-system" :
781 b->is_user ? "sd-user" : "sd";
783 _cleanup_free_ char *e = NULL;
785 e = bus_label_escape(pr);
789 g = strappend(b->is_system ? "sd-system-" :
790 b->is_user ? "sd-user-" : "sd-",
798 b->description = bus_label_unescape(name);
805 sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) +
806 ALIGN8(offsetof(struct kdbus_item, str) + m + 1);
808 if (b->fake_creds_valid)
809 sz += ALIGN8(offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds));
811 if (b->fake_pids_valid)
812 sz += ALIGN8(offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids));
815 l = strlen(b->fake_label);
816 sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1);
819 hello = alloca0_align(sz, 8);
821 hello->flags = b->hello_flags;
822 hello->attach_flags_send = _KDBUS_ATTACH_ANY;
823 hello->attach_flags_recv = b->attach_flags;
824 hello->pool_size = KDBUS_POOL_SIZE;
828 item->size = offsetof(struct kdbus_item, str) + m + 1;
829 item->type = KDBUS_ITEM_CONN_DESCRIPTION;
830 memcpy(item->str, name, m + 1);
831 item = KDBUS_ITEM_NEXT(item);
833 if (b->fake_creds_valid) {
834 item->size = offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds);
835 item->type = KDBUS_ITEM_CREDS;
836 item->creds = b->fake_creds;
838 item = KDBUS_ITEM_NEXT(item);
841 if (b->fake_pids_valid) {
842 item->size = offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids);
843 item->type = KDBUS_ITEM_PIDS;
844 item->pids = b->fake_pids;
846 item = KDBUS_ITEM_NEXT(item);
850 item->size = offsetof(struct kdbus_item, str) + l + 1;
851 item->type = KDBUS_ITEM_SECLABEL;
852 memcpy(item->str, b->fake_label, l+1);
855 r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello);
859 if (!b->kdbus_buffer) {
860 b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0);
861 if (b->kdbus_buffer == MAP_FAILED) {
862 b->kdbus_buffer = NULL;
867 /* The higher 32bit of the bus_flags fields are considered
868 * 'incompatible flags'. Refuse them all for now. */
869 if (hello->bus_flags > 0xFFFFFFFFULL)
872 if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash))
875 b->bloom_size = (size_t) hello->bloom.size;
876 b->bloom_n_hash = (unsigned) hello->bloom.n_hash;
878 if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello->id) < 0)
881 b->unique_id = hello->id;
884 b->bus_client = true;
885 b->can_fds = !!(hello->flags & KDBUS_HELLO_ACCEPT_FD);
886 b->message_version = 2;
887 b->message_endian = BUS_NATIVE_ENDIAN;
889 /* the kernel told us the UUID of the underlying bus */
890 memcpy(b->server_id.bytes, hello->id128, sizeof(b->server_id.bytes));
892 return bus_start_running(b);
895 int bus_kernel_connect(sd_bus *b) {
897 assert(b->input_fd < 0);
898 assert(b->output_fd < 0);
904 b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
908 b->output_fd = b->input_fd;
910 return bus_kernel_take_fd(b);
913 static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
914 struct kdbus_cmd_free cmd;
915 struct kdbus_item *d;
921 cmd.offset = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
923 KDBUS_ITEM_FOREACH(d, k, items) {
925 if (d->type == KDBUS_ITEM_FDS)
926 close_many(d->fds, (d->size - offsetof(struct kdbus_item, fds)) / sizeof(int));
927 else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD)
928 safe_close(d->memfd.fd);
931 (void) ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd);
934 int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call) {
939 assert(bus->state == BUS_RUNNING);
941 /* If we can't deliver, we want room for the error message */
942 r = bus_rqueue_make_room(bus);
946 r = bus_message_setup_kmsg(bus, m);
950 /* If this is a synchronous method call, then let's tell the
951 * kernel, so that it can pass CPU time/scheduling to the
952 * destination for the time, if it wants to. If we
953 * synchronously wait for the result anyway, we won't need CPU
956 m->kdbus->flags |= KDBUS_MSG_FLAGS_EXPECT_REPLY|KDBUS_MSG_FLAGS_SYNC_REPLY;
958 r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
960 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
961 sd_bus_message *reply;
963 if (errno == EAGAIN || errno == EINTR)
965 else if (errno == ENXIO || errno == ESRCH) {
967 /* ENXIO: unique name not known
968 * ESRCH: well-known name not known */
970 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
971 sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
973 log_debug("Could not deliver message to %s as destination is not known. Ignoring.", m->destination);
977 } else if (errno == EADDRNOTAVAIL) {
979 /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
981 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
982 sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
984 log_debug("Could not deliver message to %s as destination is not activated. Ignoring.", m->destination);
990 r = bus_message_new_synthetic_error(
992 BUS_MESSAGE_COOKIE(m),
999 r = bus_seal_synthetic_message(bus, reply);
1003 bus->rqueue[bus->rqueue_size++] = reply;
1005 } else if (hint_sync_call) {
1006 struct kdbus_msg *k;
1008 k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + m->kdbus->offset_reply);
1011 if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
1013 r = bus_kernel_make_message(bus, k);
1015 close_kdbus_msg(bus, k);
1017 /* Anybody can send us invalid messages, let's just drop them. */
1018 if (r == -EBADMSG || r == -EPROTOTYPE)
1019 log_debug("Ignoring invalid message: %s", strerror(-r));
1024 log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type);
1025 close_kdbus_msg(bus, k);
1032 static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) {
1033 _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
1038 r = sd_bus_message_new_signal(
1041 "/org/freedesktop/DBus",
1042 "org.freedesktop.DBus",
1043 "NameOwnerChanged");
1047 r = sd_bus_message_append(m, "sss", name, old_owner, new_owner);
1051 m->sender = "org.freedesktop.DBus";
1053 r = bus_seal_synthetic_message(bus, m);
1057 bus->rqueue[bus->rqueue_size++] = m;
1063 static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1064 char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX];
1070 if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
1073 sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old_id.id);
1075 if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
1077 if (isempty(old_owner))
1082 sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new_id.id);
1084 return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
1087 static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1088 char owner[UNIQUE_NAME_MAX];
1094 sprintf(owner, ":1.%llu", d->id_change.id);
1096 return push_name_owner_changed(
1098 d->type == KDBUS_ITEM_ID_ADD ? NULL : owner,
1099 d->type == KDBUS_ITEM_ID_ADD ? owner : NULL);
1102 static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1103 _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
1110 r = bus_message_new_synthetic_error(
1113 d->type == KDBUS_ITEM_REPLY_TIMEOUT ?
1114 &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call timed out") :
1115 &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call peer died"),
1120 m->sender = "org.freedesktop.DBus";
1122 r = bus_seal_synthetic_message(bus, m);
1126 bus->rqueue[bus->rqueue_size++] = m;
1132 static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
1133 struct kdbus_item *d, *found = NULL;
1135 static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = {
1136 [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1137 [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1138 [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1140 [KDBUS_ITEM_ID_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
1141 [KDBUS_ITEM_ID_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
1143 [KDBUS_ITEM_REPLY_TIMEOUT - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
1144 [KDBUS_ITEM_REPLY_DEAD - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
1149 assert(k->payload_type == KDBUS_PAYLOAD_KERNEL);
1151 KDBUS_ITEM_FOREACH(d, k, items) {
1152 if (d->type >= _KDBUS_ITEM_KERNEL_BASE && d->type < _KDBUS_ITEM_KERNEL_BASE + ELEMENTSOF(translate)) {
1157 log_debug("Got unknown field from kernel %llu", d->type);
1161 log_debug("Didn't find a kernel message to translate.");
1165 return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
1168 int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
1169 struct kdbus_cmd_recv recv = {};
1170 struct kdbus_msg *k;
1175 r = bus_rqueue_make_room(bus);
1179 if (hint_priority) {
1180 recv.flags |= KDBUS_RECV_USE_PRIORITY;
1181 recv.priority = priority;
1184 r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &recv);
1186 if (errno == EAGAIN)
1192 k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + recv.offset);
1193 if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
1194 r = bus_kernel_make_message(bus, k);
1196 /* Anybody can send us invalid messages, let's just drop them. */
1197 if (r == -EBADMSG || r == -EPROTOTYPE) {
1198 log_debug("Ignoring invalid message: %s", strerror(-r));
1202 } else if (k->payload_type == KDBUS_PAYLOAD_KERNEL)
1203 r = bus_kernel_translate_message(bus, k);
1205 log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type);
1210 close_kdbus_msg(bus, k);
1212 return r < 0 ? r : 1;
1215 int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated) {
1216 struct memfd_cache *c;
1223 if (!bus || !bus->is_kernel)
1226 assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0);
1228 if (bus->n_memfd_cache <= 0) {
1231 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1233 r = memfd_new(bus->description);
1243 c = &bus->memfd_cache[--bus->n_memfd_cache];
1246 assert(c->mapped == 0 || c->address);
1248 *address = c->address;
1249 *mapped = c->mapped;
1250 *allocated = c->allocated;
1253 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1258 static void close_and_munmap(int fd, void *address, size_t size) {
1260 assert_se(munmap(address, PAGE_ALIGN(size)) >= 0);
1265 void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t mapped, size_t allocated) {
1266 struct memfd_cache *c;
1267 uint64_t max_mapped = PAGE_ALIGN(MEMFD_CACHE_ITEM_SIZE_MAX);
1270 assert(mapped == 0 || address);
1272 if (!bus || !bus->is_kernel) {
1273 close_and_munmap(fd, address, mapped);
1277 assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0);
1279 if (bus->n_memfd_cache >= ELEMENTSOF(bus->memfd_cache)) {
1280 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1282 close_and_munmap(fd, address, mapped);
1286 c = &bus->memfd_cache[bus->n_memfd_cache++];
1288 c->address = address;
1290 /* If overly long, let's return a bit to the OS */
1291 if (mapped > max_mapped) {
1292 assert_se(memfd_set_size(fd, max_mapped) >= 0);
1293 assert_se(munmap((uint8_t*) address + max_mapped, PAGE_ALIGN(mapped - max_mapped)) >= 0);
1294 c->mapped = c->allocated = max_mapped;
1297 c->allocated = allocated;
1300 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1303 void bus_kernel_flush_memfd(sd_bus *b) {
1308 for (i = 0; i < b->n_memfd_cache; i++)
1309 close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped);
1312 int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
1315 assert(kdbus_flags);
1317 if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
1318 f |= KDBUS_NAME_ALLOW_REPLACEMENT;
1320 if (flags & SD_BUS_NAME_REPLACE_EXISTING)
1321 f |= KDBUS_NAME_REPLACE_EXISTING;
1323 if (flags & SD_BUS_NAME_QUEUE)
1324 f |= KDBUS_NAME_QUEUE;
1330 int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
1335 if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
1336 SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID))
1337 m |= KDBUS_ATTACH_CREDS;
1339 if (mask & (SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
1340 m |= KDBUS_ATTACH_PIDS;
1342 if (mask & SD_BUS_CREDS_COMM)
1343 m |= KDBUS_ATTACH_PID_COMM;
1345 if (mask & SD_BUS_CREDS_TID_COMM)
1346 m |= KDBUS_ATTACH_TID_COMM;
1348 if (mask & SD_BUS_CREDS_EXE)
1349 m |= KDBUS_ATTACH_EXE;
1351 if (mask & SD_BUS_CREDS_CMDLINE)
1352 m |= KDBUS_ATTACH_CMDLINE;
1354 if (mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID))
1355 m |= KDBUS_ATTACH_CGROUP;
1357 if (mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS))
1358 m |= KDBUS_ATTACH_CAPS;
1360 if (mask & SD_BUS_CREDS_SELINUX_CONTEXT)
1361 m |= KDBUS_ATTACH_SECLABEL;
1363 if (mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID))
1364 m |= KDBUS_ATTACH_AUDIT;
1366 if (mask & SD_BUS_CREDS_WELL_KNOWN_NAMES)
1367 m |= KDBUS_ATTACH_NAMES;
1369 if (mask & SD_BUS_CREDS_DESCRIPTION)
1370 m |= KDBUS_ATTACH_CONN_DESCRIPTION;
1372 if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
1373 m |= KDBUS_ATTACH_AUXGROUPS;
1379 int bus_kernel_create_bus(const char *name, bool world, char **s) {
1380 struct kdbus_cmd_make *make;
1381 struct kdbus_item *n;
1387 fd = open("/sys/fs/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
1391 make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
1392 offsetof(struct kdbus_item, data64) + sizeof(uint64_t) +
1393 offsetof(struct kdbus_item, str) +
1394 DECIMAL_STR_MAX(uid_t) + 1 + strlen(name) + 1),
1397 make->size = offsetof(struct kdbus_cmd_make, items);
1400 n->size = offsetof(struct kdbus_item, bloom_parameter) +
1401 sizeof(struct kdbus_bloom_parameter);
1402 n->type = KDBUS_ITEM_BLOOM_PARAMETER;
1404 n->bloom_parameter.size = DEFAULT_BLOOM_SIZE;
1405 n->bloom_parameter.n_hash = DEFAULT_BLOOM_N_HASH;
1407 assert_cc(DEFAULT_BLOOM_SIZE > 0);
1408 assert_cc(DEFAULT_BLOOM_N_HASH > 0);
1410 make->size += ALIGN8(n->size);
1412 n = KDBUS_ITEM_NEXT(n);
1413 sprintf(n->str, UID_FMT "-%s", getuid(), name);
1414 n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
1415 n->type = KDBUS_ITEM_MAKE_NAME;
1416 make->size += ALIGN8(n->size);
1418 make->flags = world ? KDBUS_MAKE_ACCESS_WORLD : 0;
1420 if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) {
1428 p = strjoin("/sys/fs/kdbus/", n->str, "/bus", NULL);
1440 static int bus_kernel_translate_access(BusPolicyAccess access) {
1441 assert(access >= 0);
1442 assert(access < _BUS_POLICY_ACCESS_MAX);
1446 case BUS_POLICY_ACCESS_SEE:
1447 return KDBUS_POLICY_SEE;
1449 case BUS_POLICY_ACCESS_TALK:
1450 return KDBUS_POLICY_TALK;
1452 case BUS_POLICY_ACCESS_OWN:
1453 return KDBUS_POLICY_OWN;
1456 assert_not_reached("Unknown policy access");
1460 static int bus_kernel_translate_policy(const BusNamePolicy *policy, struct kdbus_item *item) {
1466 switch (policy->type) {
1468 case BUSNAME_POLICY_TYPE_USER: {
1469 const char *user = policy->name;
1472 r = get_user_creds(&user, &uid, NULL, NULL, NULL);
1476 item->policy_access.type = KDBUS_POLICY_ACCESS_USER;
1477 item->policy_access.id = uid;
1481 case BUSNAME_POLICY_TYPE_GROUP: {
1482 const char *group = policy->name;
1485 r = get_group_creds(&group, &gid);
1489 item->policy_access.type = KDBUS_POLICY_ACCESS_GROUP;
1490 item->policy_access.id = gid;
1495 assert_not_reached("Unknown policy type");
1498 item->policy_access.access = bus_kernel_translate_access(policy->access);
1503 int bus_kernel_open_bus_fd(const char *bus, char **path) {
1508 len = strlen("/sys/fs/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
1517 sprintf(p, "/sys/fs/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
1519 fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
1526 int bus_kernel_create_endpoint(const char *bus_name, const char *ep_name, char **ep_path) {
1527 _cleanup_free_ char *path = NULL;
1528 struct kdbus_cmd_make *make;
1529 struct kdbus_item *n;
1533 fd = bus_kernel_open_bus_fd(bus_name, &path);
1537 size = ALIGN8(offsetof(struct kdbus_cmd_make, items));
1538 size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(ep_name) + 1);
1540 make = alloca0_align(size, 8);
1542 make->flags = KDBUS_MAKE_ACCESS_WORLD;
1546 n->type = KDBUS_ITEM_MAKE_NAME;
1547 n->size = offsetof(struct kdbus_item, str) + strlen(ep_name) + 1;
1548 strcpy(n->str, ep_name);
1550 if (ioctl(fd, KDBUS_CMD_ENDPOINT_MAKE, make) < 0) {
1558 p = strjoin(dirname(path), "/", ep_name, NULL);
1570 int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep) {
1572 struct kdbus_cmd_update *update;
1573 struct kdbus_item *n;
1574 BusEndpointPolicy *po;
1579 size = ALIGN8(offsetof(struct kdbus_cmd_update, items));
1581 HASHMAP_FOREACH(po, ep->policy_hash, i) {
1582 size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(po->name) + 1);
1583 size += ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
1586 update = alloca0_align(size, 8);
1587 update->size = size;
1591 HASHMAP_FOREACH(po, ep->policy_hash, i) {
1592 n->type = KDBUS_ITEM_NAME;
1593 n->size = offsetof(struct kdbus_item, str) + strlen(po->name) + 1;
1594 strcpy(n->str, po->name);
1595 n = KDBUS_ITEM_NEXT(n);
1597 n->type = KDBUS_ITEM_POLICY_ACCESS;
1598 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1600 n->policy_access.type = KDBUS_POLICY_ACCESS_USER;
1601 n->policy_access.access = bus_kernel_translate_access(po->access);
1602 n->policy_access.id = uid;
1604 n = KDBUS_ITEM_NEXT(n);
1607 r = ioctl(fd, KDBUS_CMD_ENDPOINT_UPDATE, update);
1614 int bus_kernel_make_starter(
1619 BusNamePolicy *policy,
1620 BusPolicyAccess world_policy) {
1622 struct kdbus_cmd_hello *hello;
1623 struct kdbus_item *n;
1624 size_t policy_cnt = 0;
1632 LIST_FOREACH(policy, po, policy)
1635 if (world_policy >= 0)
1638 size = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) +
1639 ALIGN8(offsetof(struct kdbus_item, str) + strlen(name) + 1) +
1640 policy_cnt * ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
1642 hello = alloca0_align(size, 8);
1645 strcpy(n->str, name);
1646 n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
1647 n->type = KDBUS_ITEM_NAME;
1648 n = KDBUS_ITEM_NEXT(n);
1650 LIST_FOREACH(policy, po, policy) {
1651 n->type = KDBUS_ITEM_POLICY_ACCESS;
1652 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1654 r = bus_kernel_translate_policy(po, n);
1658 n = KDBUS_ITEM_NEXT(n);
1661 if (world_policy >= 0) {
1662 n->type = KDBUS_ITEM_POLICY_ACCESS;
1663 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1664 n->policy_access.type = KDBUS_POLICY_ACCESS_WORLD;
1665 n->policy_access.access = bus_kernel_translate_access(world_policy);
1670 (activating ? KDBUS_HELLO_ACTIVATOR : KDBUS_HELLO_POLICY_HOLDER) |
1671 (accept_fd ? KDBUS_HELLO_ACCEPT_FD : 0);
1672 hello->pool_size = KDBUS_POOL_SIZE;
1673 hello->attach_flags_send = _KDBUS_ATTACH_ANY;
1674 hello->attach_flags_recv = _KDBUS_ATTACH_ALL;
1676 if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0)
1679 /* The higher 32bit of the bus_flags fields are considered
1680 * 'incompatible flags'. Refuse them all for now. */
1681 if (hello->bus_flags > 0xFFFFFFFFULL)
1684 if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash))
1690 int bus_kernel_try_close(sd_bus *bus) {
1692 assert(bus->is_kernel);
1694 if (ioctl(bus->input_fd, KDBUS_CMD_BYEBYE) < 0)
1700 int bus_kernel_drop_one(int fd) {
1701 struct kdbus_cmd_recv recv = {
1702 .flags = KDBUS_RECV_DROP
1707 if (ioctl(fd, KDBUS_CMD_MSG_RECV, &recv) < 0)