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))
652 destination = d->str;
655 case KDBUS_ITEM_OWNED_NAME:
656 if (!service_name_is_valid(d->name.name))
659 r = strv_extend(&m->creds.well_known_names, d->name.name);
664 case KDBUS_ITEM_CONN_DESCRIPTION:
665 m->creds.description = d->str;
666 m->creds.mask |= SD_BUS_CREDS_DESCRIPTION & bus->creds_mask;
669 case KDBUS_ITEM_AUXGROUPS:
671 if (bus->creds_mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS) {
674 n = (d->size - offsetof(struct kdbus_item, data64)) / sizeof(uint64_t);
681 for (i = 0; i < n; i++)
682 u[i] = (uid_t) d->data64[i];
684 m->creds.supplementary_gids = u;
685 m->creds.n_supplementary_gids = n;
687 m->creds.mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS;
693 case KDBUS_ITEM_SECLABEL:
697 log_debug("Got unknown field from kernel %llu", d->type);
701 r = bus_message_parse_fields(m);
705 /* Override information from the user header with data from the kernel */
706 if (k->src_id == KDBUS_SRC_ID_KERNEL)
707 m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus";
709 snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id);
710 m->sender = m->creds.unique_name = m->sender_buffer;
714 m->destination = destination;
715 else if (k->dst_id == KDBUS_DST_ID_BROADCAST)
716 m->destination = NULL;
717 else if (k->dst_id == KDBUS_DST_ID_NAME)
718 m->destination = bus->unique_name; /* fill in unique name if the well-known name is missing */
720 snprintf(m->destination_buffer, sizeof(m->destination_buffer), ":1.%llu", (unsigned long long) k->dst_id);
721 m->destination = m->destination_buffer;
724 /* We take possession of the kmsg struct now */
726 m->release_kdbus = true;
730 bus->rqueue[bus->rqueue_size++] = m;
736 sd_bus_message_unref(m);
741 int bus_kernel_take_fd(sd_bus *b) {
742 struct kdbus_cmd_hello *hello;
743 struct kdbus_item *item;
744 _cleanup_free_ char *g = NULL;
746 size_t l = 0, m = 0, sz;
756 if (b->description) {
757 g = bus_label_escape(b->description);
765 /* If no name is explicitly set, we'll include a hint
766 * indicating the library implementation, a hint which
767 * kind of bus this is and the thread name */
769 assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0);
772 name = b->is_system ? "sd-system" :
773 b->is_user ? "sd-user" : "sd";
775 _cleanup_free_ char *e = NULL;
777 e = bus_label_escape(pr);
781 g = strappend(b->is_system ? "sd-system-" :
782 b->is_user ? "sd-user-" : "sd-",
790 b->description = bus_label_unescape(name);
797 sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) +
798 ALIGN8(offsetof(struct kdbus_item, str) + m + 1);
800 if (b->fake_creds_valid)
801 sz += ALIGN8(offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds));
803 if (b->fake_pids_valid)
804 sz += ALIGN8(offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids));
807 l = strlen(b->fake_label);
808 sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1);
811 hello = alloca0_align(sz, 8);
813 hello->flags = b->hello_flags;
814 hello->attach_flags_send = _KDBUS_ATTACH_ANY;
815 hello->attach_flags_recv = b->attach_flags;
816 hello->pool_size = KDBUS_POOL_SIZE;
820 item->size = offsetof(struct kdbus_item, str) + m + 1;
821 item->type = KDBUS_ITEM_CONN_DESCRIPTION;
822 memcpy(item->str, name, m + 1);
823 item = KDBUS_ITEM_NEXT(item);
825 if (b->fake_creds_valid) {
826 item->size = offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds);
827 item->type = KDBUS_ITEM_CREDS;
828 item->creds = b->fake_creds;
830 item = KDBUS_ITEM_NEXT(item);
833 if (b->fake_pids_valid) {
834 item->size = offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids);
835 item->type = KDBUS_ITEM_PIDS;
836 item->pids = b->fake_pids;
838 item = KDBUS_ITEM_NEXT(item);
842 item->size = offsetof(struct kdbus_item, str) + l + 1;
843 item->type = KDBUS_ITEM_SECLABEL;
844 memcpy(item->str, b->fake_label, l+1);
847 r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello);
851 if (!b->kdbus_buffer) {
852 b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0);
853 if (b->kdbus_buffer == MAP_FAILED) {
854 b->kdbus_buffer = NULL;
859 /* The higher 32bit of the bus_flags fields are considered
860 * 'incompatible flags'. Refuse them all for now. */
861 if (hello->bus_flags > 0xFFFFFFFFULL)
864 if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash))
867 b->bloom_size = (size_t) hello->bloom.size;
868 b->bloom_n_hash = (unsigned) hello->bloom.n_hash;
870 if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello->id) < 0)
873 b->unique_id = hello->id;
876 b->bus_client = true;
877 b->can_fds = !!(hello->flags & KDBUS_HELLO_ACCEPT_FD);
878 b->message_version = 2;
879 b->message_endian = BUS_NATIVE_ENDIAN;
881 /* the kernel told us the UUID of the underlying bus */
882 memcpy(b->server_id.bytes, hello->id128, sizeof(b->server_id.bytes));
884 return bus_start_running(b);
887 int bus_kernel_connect(sd_bus *b) {
889 assert(b->input_fd < 0);
890 assert(b->output_fd < 0);
896 b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
900 b->output_fd = b->input_fd;
902 return bus_kernel_take_fd(b);
905 static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
906 struct kdbus_cmd_free cmd;
907 struct kdbus_item *d;
913 cmd.offset = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
915 KDBUS_ITEM_FOREACH(d, k, items) {
917 if (d->type == KDBUS_ITEM_FDS)
918 close_many(d->fds, (d->size - offsetof(struct kdbus_item, fds)) / sizeof(int));
919 else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD)
920 safe_close(d->memfd.fd);
923 (void) ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd);
926 int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call) {
931 assert(bus->state == BUS_RUNNING);
933 /* If we can't deliver, we want room for the error message */
934 r = bus_rqueue_make_room(bus);
938 r = bus_message_setup_kmsg(bus, m);
942 /* If this is a synchronous method call, then let's tell the
943 * kernel, so that it can pass CPU time/scheduling to the
944 * destination for the time, if it wants to. If we
945 * synchronously wait for the result anyway, we won't need CPU
948 m->kdbus->flags |= KDBUS_MSG_FLAGS_EXPECT_REPLY|KDBUS_MSG_FLAGS_SYNC_REPLY;
950 r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
952 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
953 sd_bus_message *reply;
955 if (errno == EAGAIN || errno == EINTR)
957 else if (errno == ENXIO || errno == ESRCH) {
959 /* ENXIO: unique name not known
960 * ESRCH: well-known name not known */
962 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
963 sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
965 log_debug("Could not deliver message to %s as destination is not known. Ignoring.", m->destination);
969 } else if (errno == EADDRNOTAVAIL) {
971 /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
973 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
974 sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
976 log_debug("Could not deliver message to %s as destination is not activated. Ignoring.", m->destination);
982 r = bus_message_new_synthetic_error(
984 BUS_MESSAGE_COOKIE(m),
991 r = bus_seal_synthetic_message(bus, reply);
995 bus->rqueue[bus->rqueue_size++] = reply;
997 } else if (hint_sync_call) {
1000 k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + m->kdbus->offset_reply);
1003 if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
1005 r = bus_kernel_make_message(bus, k);
1007 close_kdbus_msg(bus, k);
1009 /* Anybody can send us invalid messages, let's just drop them. */
1010 if (r == -EBADMSG || r == -EPROTOTYPE)
1011 log_debug("Ignoring invalid message: %s", strerror(-r));
1016 log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type);
1017 close_kdbus_msg(bus, k);
1024 static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) {
1025 _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
1030 r = sd_bus_message_new_signal(
1033 "/org/freedesktop/DBus",
1034 "org.freedesktop.DBus",
1035 "NameOwnerChanged");
1039 r = sd_bus_message_append(m, "sss", name, old_owner, new_owner);
1043 m->sender = "org.freedesktop.DBus";
1045 r = bus_seal_synthetic_message(bus, m);
1049 bus->rqueue[bus->rqueue_size++] = m;
1055 static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1056 char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX];
1062 if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
1065 sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old_id.id);
1067 if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
1069 if (isempty(old_owner))
1074 sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new_id.id);
1076 return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
1079 static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1080 char owner[UNIQUE_NAME_MAX];
1086 sprintf(owner, ":1.%llu", d->id_change.id);
1088 return push_name_owner_changed(
1090 d->type == KDBUS_ITEM_ID_ADD ? NULL : owner,
1091 d->type == KDBUS_ITEM_ID_ADD ? owner : NULL);
1094 static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
1095 _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
1102 r = bus_message_new_synthetic_error(
1105 d->type == KDBUS_ITEM_REPLY_TIMEOUT ?
1106 &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call timed out") :
1107 &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call peer died"),
1112 m->sender = "org.freedesktop.DBus";
1114 r = bus_seal_synthetic_message(bus, m);
1118 bus->rqueue[bus->rqueue_size++] = m;
1124 static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
1125 struct kdbus_item *d, *found = NULL;
1127 static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = {
1128 [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1129 [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1130 [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
1132 [KDBUS_ITEM_ID_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
1133 [KDBUS_ITEM_ID_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
1135 [KDBUS_ITEM_REPLY_TIMEOUT - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
1136 [KDBUS_ITEM_REPLY_DEAD - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
1141 assert(k->payload_type == KDBUS_PAYLOAD_KERNEL);
1143 KDBUS_ITEM_FOREACH(d, k, items) {
1144 if (d->type >= _KDBUS_ITEM_KERNEL_BASE && d->type < _KDBUS_ITEM_KERNEL_BASE + ELEMENTSOF(translate)) {
1149 log_debug("Got unknown field from kernel %llu", d->type);
1153 log_debug("Didn't find a kernel message to translate.");
1157 return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
1160 int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
1161 struct kdbus_cmd_recv recv = {};
1162 struct kdbus_msg *k;
1167 r = bus_rqueue_make_room(bus);
1171 if (hint_priority) {
1172 recv.flags |= KDBUS_RECV_USE_PRIORITY;
1173 recv.priority = priority;
1176 r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &recv);
1178 if (errno == EAGAIN)
1184 k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + recv.offset);
1185 if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
1186 r = bus_kernel_make_message(bus, k);
1188 /* Anybody can send us invalid messages, let's just drop them. */
1189 if (r == -EBADMSG || r == -EPROTOTYPE) {
1190 log_debug("Ignoring invalid message: %s", strerror(-r));
1194 } else if (k->payload_type == KDBUS_PAYLOAD_KERNEL)
1195 r = bus_kernel_translate_message(bus, k);
1197 log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type);
1202 close_kdbus_msg(bus, k);
1204 return r < 0 ? r : 1;
1207 int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated) {
1208 struct memfd_cache *c;
1215 if (!bus || !bus->is_kernel)
1218 assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0);
1220 if (bus->n_memfd_cache <= 0) {
1223 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1225 r = memfd_new(bus->description);
1235 c = &bus->memfd_cache[--bus->n_memfd_cache];
1238 assert(c->mapped == 0 || c->address);
1240 *address = c->address;
1241 *mapped = c->mapped;
1242 *allocated = c->allocated;
1245 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1250 static void close_and_munmap(int fd, void *address, size_t size) {
1252 assert_se(munmap(address, PAGE_ALIGN(size)) >= 0);
1257 void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t mapped, size_t allocated) {
1258 struct memfd_cache *c;
1259 uint64_t max_mapped = PAGE_ALIGN(MEMFD_CACHE_ITEM_SIZE_MAX);
1262 assert(mapped == 0 || address);
1264 if (!bus || !bus->is_kernel) {
1265 close_and_munmap(fd, address, mapped);
1269 assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0);
1271 if (bus->n_memfd_cache >= ELEMENTSOF(bus->memfd_cache)) {
1272 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1274 close_and_munmap(fd, address, mapped);
1278 c = &bus->memfd_cache[bus->n_memfd_cache++];
1280 c->address = address;
1282 /* If overly long, let's return a bit to the OS */
1283 if (mapped > max_mapped) {
1284 assert_se(memfd_set_size(fd, max_mapped) >= 0);
1285 assert_se(munmap((uint8_t*) address + max_mapped, PAGE_ALIGN(mapped - max_mapped)) >= 0);
1286 c->mapped = c->allocated = max_mapped;
1289 c->allocated = allocated;
1292 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
1295 void bus_kernel_flush_memfd(sd_bus *b) {
1300 for (i = 0; i < b->n_memfd_cache; i++)
1301 close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped);
1304 int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
1307 assert(kdbus_flags);
1309 if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
1310 f |= KDBUS_NAME_ALLOW_REPLACEMENT;
1312 if (flags & SD_BUS_NAME_REPLACE_EXISTING)
1313 f |= KDBUS_NAME_REPLACE_EXISTING;
1315 if (flags & SD_BUS_NAME_QUEUE)
1316 f |= KDBUS_NAME_QUEUE;
1322 int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
1327 if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
1328 SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID))
1329 m |= KDBUS_ATTACH_CREDS;
1331 if (mask & (SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
1332 m |= KDBUS_ATTACH_PIDS;
1334 if (mask & SD_BUS_CREDS_COMM)
1335 m |= KDBUS_ATTACH_PID_COMM;
1337 if (mask & SD_BUS_CREDS_TID_COMM)
1338 m |= KDBUS_ATTACH_TID_COMM;
1340 if (mask & SD_BUS_CREDS_EXE)
1341 m |= KDBUS_ATTACH_EXE;
1343 if (mask & SD_BUS_CREDS_CMDLINE)
1344 m |= KDBUS_ATTACH_CMDLINE;
1346 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))
1347 m |= KDBUS_ATTACH_CGROUP;
1349 if (mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS))
1350 m |= KDBUS_ATTACH_CAPS;
1352 if (mask & SD_BUS_CREDS_SELINUX_CONTEXT)
1353 m |= KDBUS_ATTACH_SECLABEL;
1355 if (mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID))
1356 m |= KDBUS_ATTACH_AUDIT;
1358 if (mask & SD_BUS_CREDS_WELL_KNOWN_NAMES)
1359 m |= KDBUS_ATTACH_NAMES;
1361 if (mask & SD_BUS_CREDS_DESCRIPTION)
1362 m |= KDBUS_ATTACH_CONN_DESCRIPTION;
1364 if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
1365 m |= KDBUS_ATTACH_AUXGROUPS;
1371 int bus_kernel_create_bus(const char *name, bool world, char **s) {
1372 struct kdbus_cmd_make *make;
1373 struct kdbus_item *n;
1379 fd = open("/sys/fs/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
1383 make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
1384 offsetof(struct kdbus_item, data64) + sizeof(uint64_t) +
1385 offsetof(struct kdbus_item, str) +
1386 DECIMAL_STR_MAX(uid_t) + 1 + strlen(name) + 1),
1389 make->size = offsetof(struct kdbus_cmd_make, items);
1392 n->size = offsetof(struct kdbus_item, bloom_parameter) +
1393 sizeof(struct kdbus_bloom_parameter);
1394 n->type = KDBUS_ITEM_BLOOM_PARAMETER;
1396 n->bloom_parameter.size = DEFAULT_BLOOM_SIZE;
1397 n->bloom_parameter.n_hash = DEFAULT_BLOOM_N_HASH;
1399 assert_cc(DEFAULT_BLOOM_SIZE > 0);
1400 assert_cc(DEFAULT_BLOOM_N_HASH > 0);
1402 make->size += ALIGN8(n->size);
1404 n = KDBUS_ITEM_NEXT(n);
1405 sprintf(n->str, UID_FMT "-%s", getuid(), name);
1406 n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
1407 n->type = KDBUS_ITEM_MAKE_NAME;
1408 make->size += ALIGN8(n->size);
1410 make->flags = world ? KDBUS_MAKE_ACCESS_WORLD : 0;
1412 if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) {
1420 p = strjoin("/sys/fs/kdbus/", n->str, "/bus", NULL);
1432 static int bus_kernel_translate_access(BusPolicyAccess access) {
1433 assert(access >= 0);
1434 assert(access < _BUS_POLICY_ACCESS_MAX);
1438 case BUS_POLICY_ACCESS_SEE:
1439 return KDBUS_POLICY_SEE;
1441 case BUS_POLICY_ACCESS_TALK:
1442 return KDBUS_POLICY_TALK;
1444 case BUS_POLICY_ACCESS_OWN:
1445 return KDBUS_POLICY_OWN;
1448 assert_not_reached("Unknown policy access");
1452 static int bus_kernel_translate_policy(const BusNamePolicy *policy, struct kdbus_item *item) {
1458 switch (policy->type) {
1460 case BUSNAME_POLICY_TYPE_USER: {
1461 const char *user = policy->name;
1464 r = get_user_creds(&user, &uid, NULL, NULL, NULL);
1468 item->policy_access.type = KDBUS_POLICY_ACCESS_USER;
1469 item->policy_access.id = uid;
1473 case BUSNAME_POLICY_TYPE_GROUP: {
1474 const char *group = policy->name;
1477 r = get_group_creds(&group, &gid);
1481 item->policy_access.type = KDBUS_POLICY_ACCESS_GROUP;
1482 item->policy_access.id = gid;
1487 assert_not_reached("Unknown policy type");
1490 item->policy_access.access = bus_kernel_translate_access(policy->access);
1495 int bus_kernel_open_bus_fd(const char *bus, char **path) {
1500 len = strlen("/sys/fs/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
1509 sprintf(p, "/sys/fs/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
1511 fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
1518 int bus_kernel_create_endpoint(const char *bus_name, const char *ep_name, char **ep_path) {
1519 _cleanup_free_ char *path = NULL;
1520 struct kdbus_cmd_make *make;
1521 struct kdbus_item *n;
1525 fd = bus_kernel_open_bus_fd(bus_name, &path);
1529 size = ALIGN8(offsetof(struct kdbus_cmd_make, items));
1530 size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(ep_name) + 1);
1532 make = alloca0_align(size, 8);
1534 make->flags = KDBUS_MAKE_ACCESS_WORLD;
1538 n->type = KDBUS_ITEM_MAKE_NAME;
1539 n->size = offsetof(struct kdbus_item, str) + strlen(ep_name) + 1;
1540 strcpy(n->str, ep_name);
1542 if (ioctl(fd, KDBUS_CMD_ENDPOINT_MAKE, make) < 0) {
1550 p = strjoin(dirname(path), "/", ep_name, NULL);
1562 int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep) {
1564 struct kdbus_cmd_update *update;
1565 struct kdbus_item *n;
1566 BusEndpointPolicy *po;
1571 size = ALIGN8(offsetof(struct kdbus_cmd_update, items));
1573 HASHMAP_FOREACH(po, ep->policy_hash, i) {
1574 size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(po->name) + 1);
1575 size += ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
1578 update = alloca0_align(size, 8);
1579 update->size = size;
1583 HASHMAP_FOREACH(po, ep->policy_hash, i) {
1584 n->type = KDBUS_ITEM_NAME;
1585 n->size = offsetof(struct kdbus_item, str) + strlen(po->name) + 1;
1586 strcpy(n->str, po->name);
1587 n = KDBUS_ITEM_NEXT(n);
1589 n->type = KDBUS_ITEM_POLICY_ACCESS;
1590 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1592 n->policy_access.type = KDBUS_POLICY_ACCESS_USER;
1593 n->policy_access.access = bus_kernel_translate_access(po->access);
1594 n->policy_access.id = uid;
1596 n = KDBUS_ITEM_NEXT(n);
1599 r = ioctl(fd, KDBUS_CMD_ENDPOINT_UPDATE, update);
1606 int bus_kernel_make_starter(
1611 BusNamePolicy *policy,
1612 BusPolicyAccess world_policy) {
1614 struct kdbus_cmd_hello *hello;
1615 struct kdbus_item *n;
1616 size_t policy_cnt = 0;
1624 LIST_FOREACH(policy, po, policy)
1627 if (world_policy >= 0)
1630 size = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) +
1631 ALIGN8(offsetof(struct kdbus_item, str) + strlen(name) + 1) +
1632 policy_cnt * ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
1634 hello = alloca0_align(size, 8);
1637 strcpy(n->str, name);
1638 n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
1639 n->type = KDBUS_ITEM_NAME;
1640 n = KDBUS_ITEM_NEXT(n);
1642 LIST_FOREACH(policy, po, policy) {
1643 n->type = KDBUS_ITEM_POLICY_ACCESS;
1644 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1646 r = bus_kernel_translate_policy(po, n);
1650 n = KDBUS_ITEM_NEXT(n);
1653 if (world_policy >= 0) {
1654 n->type = KDBUS_ITEM_POLICY_ACCESS;
1655 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
1656 n->policy_access.type = KDBUS_POLICY_ACCESS_WORLD;
1657 n->policy_access.access = bus_kernel_translate_access(world_policy);
1662 (activating ? KDBUS_HELLO_ACTIVATOR : KDBUS_HELLO_POLICY_HOLDER) |
1663 (accept_fd ? KDBUS_HELLO_ACCEPT_FD : 0);
1664 hello->pool_size = KDBUS_POOL_SIZE;
1665 hello->attach_flags_send = _KDBUS_ATTACH_ANY;
1666 hello->attach_flags_recv = _KDBUS_ATTACH_ALL;
1668 if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0)
1671 /* The higher 32bit of the bus_flags fields are considered
1672 * 'incompatible flags'. Refuse them all for now. */
1673 if (hello->bus_flags > 0xFFFFFFFFULL)
1676 if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash))
1682 int bus_kernel_try_close(sd_bus *bus) {
1684 assert(bus->is_kernel);
1686 if (ioctl(bus->input_fd, KDBUS_CMD_BYEBYE) < 0)
1692 int bus_kernel_drop_one(int fd) {
1693 struct kdbus_cmd_recv recv = {
1694 .flags = KDBUS_RECV_DROP
1699 if (ioctl(fd, KDBUS_CMD_MSG_RECV, &recv) < 0)