/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2013 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 . ***/ #ifdef HAVE_VALGRIND_MEMCHECK_H #include #endif #include #include #include #include #include #include "util.h" #include "strv.h" #include "memfd-util.h" #include "bus-internal.h" #include "bus-message.h" #include "bus-kernel.h" #include "bus-bloom.h" #include "bus-util.h" #include "bus-label.h" #include "cgroup-util.h" #define UNIQUE_NAME_MAX (3+DECIMAL_STR_MAX(uint64_t)) int bus_kernel_parse_unique_name(const char *s, uint64_t *id) { int r; assert(s); assert(id); if (!startswith(s, ":1.")) return 0; r = safe_atou64(s + 3, id); if (r < 0) return r; return 1; } static void append_payload_vec(struct kdbus_item **d, const void *p, size_t sz) { assert(d); assert(sz > 0); *d = ALIGN8_PTR(*d); /* Note that p can be NULL, which encodes a region full of * zeroes, which is useful to optimize certain padding * conditions */ (*d)->size = offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec); (*d)->type = KDBUS_ITEM_PAYLOAD_VEC; (*d)->vec.address = PTR_TO_UINT64(p); (*d)->vec.size = sz; *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size); } static void append_payload_memfd(struct kdbus_item **d, int memfd, size_t sz) { assert(d); assert(memfd >= 0); assert(sz > 0); *d = ALIGN8_PTR(*d); (*d)->size = offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd); (*d)->type = KDBUS_ITEM_PAYLOAD_MEMFD; (*d)->memfd.fd = memfd; (*d)->memfd.size = sz; *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size); } static void append_destination(struct kdbus_item **d, const char *s, size_t length) { assert(d); assert(s); *d = ALIGN8_PTR(*d); (*d)->size = offsetof(struct kdbus_item, str) + length + 1; (*d)->type = KDBUS_ITEM_DST_NAME; memcpy((*d)->str, s, length + 1); *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size); } static struct kdbus_bloom_filter *append_bloom(struct kdbus_item **d, size_t length) { struct kdbus_item *i; assert(d); i = ALIGN8_PTR(*d); i->size = offsetof(struct kdbus_item, bloom_filter) + offsetof(struct kdbus_bloom_filter, data) + length; i->type = KDBUS_ITEM_BLOOM_FILTER; *d = (struct kdbus_item *) ((uint8_t*) i + i->size); return &i->bloom_filter; } static void append_fds(struct kdbus_item **d, const int fds[], unsigned n_fds) { assert(d); assert(fds); assert(n_fds > 0); *d = ALIGN8_PTR(*d); (*d)->size = offsetof(struct kdbus_item, fds) + sizeof(int) * n_fds; (*d)->type = KDBUS_ITEM_FDS; memcpy((*d)->fds, fds, sizeof(int) * n_fds); *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size); } static int bus_message_setup_bloom(sd_bus_message *m, struct kdbus_bloom_filter *bloom) { void *data; unsigned i; int r; assert(m); assert(bloom); data = bloom->data; memzero(data, m->bus->bloom_size); bloom->generation = 0; bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "message-type", bus_message_type_to_string(m->header->type)); if (m->interface) bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "interface", m->interface); if (m->member) bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "member", m->member); if (m->path) { bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path", m->path); bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path-slash-prefix", m->path); bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, "path-slash-prefix", m->path, '/'); } r = sd_bus_message_rewind(m, true); if (r < 0) return r; for (i = 0; i < 64; i++) { char type; const char *t; char buf[sizeof("arg")-1 + 2 + sizeof("-slash-prefix")]; char *e; r = sd_bus_message_peek_type(m, &type, NULL); if (r < 0) return r; if (type != SD_BUS_TYPE_STRING && type != SD_BUS_TYPE_OBJECT_PATH && type != SD_BUS_TYPE_SIGNATURE) break; r = sd_bus_message_read_basic(m, type, &t); if (r < 0) return r; e = stpcpy(buf, "arg"); if (i < 10) *(e++) = '0' + (char) i; else { *(e++) = '0' + (char) (i / 10); *(e++) = '0' + (char) (i % 10); } *e = 0; bloom_add_pair(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t); strcpy(e, "-dot-prefix"); bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t, '.'); strcpy(e, "-slash-prefix"); bloom_add_prefixes(data, m->bus->bloom_size, m->bus->bloom_n_hash, buf, t, '/'); } return 0; } static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) { struct bus_body_part *part; struct kdbus_item *d; const char *destination; bool well_known; uint64_t unique; size_t sz, dl; unsigned i; int r; assert(b); assert(m); assert(m->sealed); /* We put this together only once, if this message is reused * we reuse the earlier-built version */ if (m->kdbus) return 0; destination = m->destination ?: m->destination_ptr; if (destination) { r = bus_kernel_parse_unique_name(destination, &unique); if (r < 0) return r; well_known = r == 0; } else well_known = false; sz = offsetof(struct kdbus_msg, items); assert_cc(ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec)) == ALIGN8(offsetof(struct kdbus_item, memfd) + sizeof(struct kdbus_memfd))); /* Add in fixed header, fields header and payload */ sz += (1 + m->n_body_parts) * ALIGN8(offsetof(struct kdbus_item, vec) + sizeof(struct kdbus_vec)); /* Add space for bloom filter */ sz += ALIGN8(offsetof(struct kdbus_item, bloom_filter) + offsetof(struct kdbus_bloom_filter, data) + m->bus->bloom_size); /* Add in well-known destination header */ if (well_known) { dl = strlen(destination); sz += ALIGN8(offsetof(struct kdbus_item, str) + dl + 1); } /* Add space for unix fds */ if (m->n_fds > 0) sz += ALIGN8(offsetof(struct kdbus_item, fds) + sizeof(int)*m->n_fds); m->kdbus = memalign(8, sz); if (!m->kdbus) { r = -ENOMEM; goto fail; } m->free_kdbus = true; memzero(m->kdbus, sz); m->kdbus->flags = ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) | ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0); if (well_known) { /* verify_destination_id will usually be 0, which makes the kernel driver only look * at the provided well-known name. Otherwise, the kernel will make sure the provided * destination id matches the owner of the provided weel-known-name, and fail if they * differ. Currently, this is only needed for bus-proxyd. */ m->kdbus->dst_id = m->verify_destination_id; } else { m->kdbus->dst_id = destination ? unique : KDBUS_DST_ID_BROADCAST; } m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS; m->kdbus->cookie = (uint64_t) m->header->serial; m->kdbus->priority = m->priority; if (m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) { m->kdbus->cookie_reply = m->reply_cookie; } else { struct timespec now; assert_se(clock_gettime(CLOCK_MONOTONIC_COARSE, &now) == 0); m->kdbus->timeout_ns = now.tv_sec * NSEC_PER_SEC + now.tv_nsec + m->timeout * NSEC_PER_USEC; } d = m->kdbus->items; if (well_known) append_destination(&d, destination, dl); append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m)); MESSAGE_FOREACH_PART(part, i, m) { if (part->is_zero) { /* If this is padding then simply send a * vector with a NULL data pointer which the * kernel will just pass through. This is the * most efficient way to encode zeroes */ append_payload_vec(&d, NULL, part->size); continue; } if (part->memfd >= 0 && part->sealed && destination) { /* Try to send a memfd, if the part is * sealed and this is not a broadcast. Since we can only */ append_payload_memfd(&d, part->memfd, part->size); continue; } /* Otherwise, let's send a vector to the actual data. * For that, we need to map it first. */ r = bus_body_part_map(part); if (r < 0) goto fail; append_payload_vec(&d, part->data, part->size); } if (m->kdbus->dst_id == KDBUS_DST_ID_BROADCAST) { struct kdbus_bloom_filter *bloom; bloom = append_bloom(&d, m->bus->bloom_size); r = bus_message_setup_bloom(m, bloom); if (r < 0) goto fail; } if (m->n_fds > 0) append_fds(&d, m->fds, m->n_fds); m->kdbus->size = (uint8_t*) d - (uint8_t*) m->kdbus; assert(m->kdbus->size <= sz); return 0; fail: m->poisoned = true; return r; } static void unset_memfds(struct sd_bus_message *m) { struct bus_body_part *part; unsigned i; assert(m); /* Make sure the memfds are not freed twice */ MESSAGE_FOREACH_PART(part, i, m) if (part->memfd >= 0) part->memfd = -1; } static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) { sd_bus_message *m = NULL; struct kdbus_item *d; unsigned n_fds = 0; _cleanup_free_ int *fds = NULL; struct bus_header *h = NULL; size_t total, n_bytes = 0, idx = 0; const char *destination = NULL, *seclabel = NULL; int r; assert(bus); assert(k); assert(k->payload_type == KDBUS_PAYLOAD_DBUS); KDBUS_ITEM_FOREACH(d, k, items) { size_t l; l = d->size - offsetof(struct kdbus_item, data); switch (d->type) { case KDBUS_ITEM_PAYLOAD_OFF: if (!h) { h = (struct bus_header *)((uint8_t *)k + d->vec.offset); if (!bus_header_is_complete(h, d->vec.size)) return -EBADMSG; } n_bytes += d->vec.size; break; case KDBUS_ITEM_PAYLOAD_MEMFD: if (!h) return -EBADMSG; n_bytes += d->memfd.size; break; case KDBUS_ITEM_FDS: { int *f; unsigned j; j = l / sizeof(int); f = realloc(fds, sizeof(int) * (n_fds + j)); if (!f) return -ENOMEM; fds = f; memcpy(fds + n_fds, d->fds, sizeof(int) * j); n_fds += j; break; } case KDBUS_ITEM_SECLABEL: seclabel = d->str; break; } } if (!h) return -EBADMSG; r = bus_header_message_size(h, &total); if (r < 0) return r; if (n_bytes != total) return -EBADMSG; /* on kdbus we only speak native endian gvariant, never dbus1 * marshalling or reverse endian */ if (h->version != 2 || h->endian != BUS_NATIVE_ENDIAN) return -EPROTOTYPE; r = bus_message_from_header(bus, h, sizeof(struct bus_header), fds, n_fds, NULL, seclabel, 0, &m); if (r < 0) return r; /* The well-known names list is different from the other credentials. If we asked for it, but nothing is there, this means that the list of well-known names is simply empty, not that we lack any data */ m->creds.mask |= (SD_BUS_CREDS_UNIQUE_NAME|SD_BUS_CREDS_WELL_KNOWN_NAMES) & bus->creds_mask; KDBUS_ITEM_FOREACH(d, k, items) { size_t l; l = d->size - offsetof(struct kdbus_item, data); switch (d->type) { case KDBUS_ITEM_PAYLOAD_OFF: { size_t begin_body; begin_body = BUS_MESSAGE_BODY_BEGIN(m); if (idx + d->vec.size > begin_body) { struct bus_body_part *part; /* Contains body material */ part = message_append_part(m); if (!part) { r = -ENOMEM; goto fail; } /* A -1 offset is NUL padding. */ part->is_zero = d->vec.offset == ~0ULL; if (idx >= begin_body) { if (!part->is_zero) part->data = (uint8_t *)k + d->vec.offset; part->size = d->vec.size; } else { if (!part->is_zero) part->data = (uint8_t *)k + d->vec.offset + (begin_body - idx); part->size = d->vec.size - (begin_body - idx); } part->sealed = true; } idx += d->vec.size; break; } case KDBUS_ITEM_PAYLOAD_MEMFD: { struct bus_body_part *part; if (idx < BUS_MESSAGE_BODY_BEGIN(m)) { r = -EBADMSG; goto fail; } part = message_append_part(m); if (!part) { r = -ENOMEM; goto fail; } part->memfd = d->memfd.fd; part->size = d->memfd.size; part->sealed = true; idx += d->memfd.size; break; } case KDBUS_ITEM_CREDS: /* UID/GID/PID are always valid */ m->creds.uid = (uid_t) d->creds.uid; m->creds.gid = (gid_t) d->creds.gid; m->creds.pid = (pid_t) d->creds.pid; m->creds.mask |= (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID) & bus->creds_mask; /* The PID starttime/TID might be missing * however, when the data is faked by some * data bus proxy and it lacks that * information about the real client since * SO_PEERCRED is used for that */ if (d->creds.starttime > 0) { m->creds.pid_starttime = d->creds.starttime / NSEC_PER_USEC; m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask; } if (d->creds.tid > 0) { m->creds.tid = (pid_t) d->creds.tid; m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask; } break; case KDBUS_ITEM_TIMESTAMP: if (bus->attach_flags & KDBUS_ATTACH_TIMESTAMP) { m->realtime = d->timestamp.realtime_ns / NSEC_PER_USEC; m->monotonic = d->timestamp.monotonic_ns / NSEC_PER_USEC; m->seqnum = d->timestamp.seqnum; } break; case KDBUS_ITEM_PID_COMM: m->creds.comm = d->str; m->creds.mask |= SD_BUS_CREDS_COMM & bus->creds_mask; break; case KDBUS_ITEM_TID_COMM: m->creds.tid_comm = d->str; m->creds.mask |= SD_BUS_CREDS_TID_COMM & bus->creds_mask; break; case KDBUS_ITEM_EXE: m->creds.exe = d->str; m->creds.mask |= SD_BUS_CREDS_EXE & bus->creds_mask; break; case KDBUS_ITEM_CMDLINE: m->creds.cmdline = d->str; m->creds.cmdline_size = l; m->creds.mask |= SD_BUS_CREDS_CMDLINE & bus->creds_mask; break; case KDBUS_ITEM_CGROUP: m->creds.cgroup = d->str; 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; r = bus_get_root_path(bus); if (r < 0) goto fail; m->creds.cgroup_root = bus->cgroup_root; break; case KDBUS_ITEM_AUDIT: m->creds.audit_session_id = (uint32_t) d->audit.sessionid; m->creds.audit_login_uid = (uid_t) d->audit.loginuid; m->creds.mask |= (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID) & bus->creds_mask; break; case KDBUS_ITEM_CAPS: m->creds.capability = (uint8_t *) d->caps.caps; m->creds.capability_size = d->size - offsetof(struct kdbus_item, caps.caps); 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; break; case KDBUS_ITEM_DST_NAME: if (!service_name_is_valid(d->str)) return -EBADMSG; destination = d->str; break; case KDBUS_ITEM_OWNED_NAME: if (!service_name_is_valid(d->name.name)) return -EBADMSG; r = strv_extend(&m->creds.well_known_names, d->name.name); if (r < 0) goto fail; break; case KDBUS_ITEM_CONN_DESCRIPTION: m->creds.description = d->str; m->creds.mask |= SD_BUS_CREDS_DESCRIPTION & bus->creds_mask; break; case KDBUS_ITEM_FDS: case KDBUS_ITEM_SECLABEL: break; default: log_debug("Got unknown field from kernel %llu", d->type); } } r = bus_message_parse_fields(m); if (r < 0) goto fail; /* Override information from the user header with data from the kernel */ if (k->src_id == KDBUS_SRC_ID_KERNEL) m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus"; else { snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id); m->sender = m->creds.unique_name = m->sender_buffer; } if (destination) m->destination = destination; else if (k->dst_id == KDBUS_DST_ID_BROADCAST) m->destination = NULL; else if (k->dst_id == KDBUS_DST_ID_NAME) m->destination = bus->unique_name; /* fill in unique name if the well-known name is missing */ else { snprintf(m->destination_buffer, sizeof(m->destination_buffer), ":1.%llu", (unsigned long long) k->dst_id); m->destination = m->destination_buffer; } /* We take possession of the kmsg struct now */ m->kdbus = k; m->release_kdbus = true; m->free_fds = true; fds = NULL; bus->rqueue[bus->rqueue_size++] = m; return 1; fail: unset_memfds(m); sd_bus_message_unref(m); return r; } int bus_kernel_take_fd(sd_bus *b) { struct kdbus_cmd_hello *hello; struct kdbus_item *item; _cleanup_free_ char *g = NULL; const char *name; size_t l = 0, m = 0, sz; int r; assert(b); if (b->is_server) return -EINVAL; b->use_memfd = 1; if (b->description) { g = bus_label_escape(b->description); if (!g) return -ENOMEM; name = g; } else { char pr[17] = {}; /* If no name is explicitly set, we'll include a hint * indicating the library implementation, a hint which * kind of bus this is and the thread name */ assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0); if (isempty(pr)) { name = b->is_system ? "sd-system" : b->is_user ? "sd-user" : "sd"; } else { _cleanup_free_ char *e = NULL; e = bus_label_escape(pr); if (!e) return -ENOMEM; g = strappend(b->is_system ? "sd-system-" : b->is_user ? "sd-user-" : "sd-", e); if (!g) return -ENOMEM; name = g; } b->description = bus_label_unescape(name); if (!b->description) return -ENOMEM; } m = strlen(name); sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) + ALIGN8(offsetof(struct kdbus_item, str) + m + 1); if (b->fake_creds_valid) sz += ALIGN8(offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds)); if (b->fake_label) { l = strlen(b->fake_label); sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1); } hello = alloca0_align(sz, 8); hello->size = sz; hello->flags = b->hello_flags; hello->attach_flags_send = _KDBUS_ATTACH_ANY; hello->attach_flags_recv = b->attach_flags; hello->pool_size = KDBUS_POOL_SIZE; item = hello->items; item->size = offsetof(struct kdbus_item, str) + m + 1; item->type = KDBUS_ITEM_CONN_DESCRIPTION; memcpy(item->str, name, m + 1); item = KDBUS_ITEM_NEXT(item); if (b->fake_creds_valid) { item->size = offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds); item->type = KDBUS_ITEM_CREDS; item->creds = b->fake_creds; item = KDBUS_ITEM_NEXT(item); } if (b->fake_label) { item->size = offsetof(struct kdbus_item, str) + l + 1; item->type = KDBUS_ITEM_SECLABEL; memcpy(item->str, b->fake_label, l+1); } r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello); if (r < 0) return -errno; if (!b->kdbus_buffer) { b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0); if (b->kdbus_buffer == MAP_FAILED) { b->kdbus_buffer = NULL; return -errno; } } /* The higher 32bit of the bus_flags fields are considered * 'incompatible flags'. Refuse them all for now. */ if (hello->bus_flags > 0xFFFFFFFFULL) return -ENOTSUP; if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash)) return -ENOTSUP; b->bloom_size = (size_t) hello->bloom.size; b->bloom_n_hash = (unsigned) hello->bloom.n_hash; if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello->id) < 0) return -ENOMEM; b->unique_id = hello->id; b->is_kernel = true; b->bus_client = true; b->can_fds = !!(hello->flags & KDBUS_HELLO_ACCEPT_FD); b->message_version = 2; b->message_endian = BUS_NATIVE_ENDIAN; /* the kernel told us the UUID of the underlying bus */ memcpy(b->server_id.bytes, hello->id128, sizeof(b->server_id.bytes)); return bus_start_running(b); } int bus_kernel_connect(sd_bus *b) { assert(b); assert(b->input_fd < 0); assert(b->output_fd < 0); assert(b->kernel); if (b->is_server) return -EINVAL; b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC); if (b->input_fd < 0) return -errno; b->output_fd = b->input_fd; return bus_kernel_take_fd(b); } static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) { struct kdbus_cmd_free cmd; struct kdbus_item *d; assert(bus); assert(k); cmd.flags = 0; cmd.offset = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer; KDBUS_ITEM_FOREACH(d, k, items) { if (d->type == KDBUS_ITEM_FDS) close_many(d->fds, (d->size - offsetof(struct kdbus_item, fds)) / sizeof(int)); else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD) safe_close(d->memfd.fd); } (void) ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd); } int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call) { int r; assert(bus); assert(m); assert(bus->state == BUS_RUNNING); /* If we can't deliver, we want room for the error message */ r = bus_rqueue_make_room(bus); if (r < 0) return r; r = bus_message_setup_kmsg(bus, m); if (r < 0) return r; /* If this is a synchronous method call, then let's tell the * kernel, so that it can pass CPU time/scheduling to the * destination for the time, if it wants to. If we * synchronously wait for the result anyway, we won't need CPU * anyway. */ if (hint_sync_call) m->kdbus->flags |= KDBUS_MSG_FLAGS_EXPECT_REPLY|KDBUS_MSG_FLAGS_SYNC_REPLY; r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus); if (r < 0) { _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; sd_bus_message *reply; if (errno == EAGAIN || errno == EINTR) return 0; else if (errno == ENXIO || errno == ESRCH) { /* ENXIO: unique name not known * ESRCH: well-known name not known */ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL) sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination); else { log_debug("Could not deliver message to %s as destination is not known. Ignoring.", m->destination); return 0; } } else if (errno == EADDRNOTAVAIL) { /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL) sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination); else { log_debug("Could not deliver message to %s as destination is not activated. Ignoring.", m->destination); return 0; } } else return -errno; r = bus_message_new_synthetic_error( bus, BUS_MESSAGE_COOKIE(m), &error, &reply); if (r < 0) return r; r = bus_seal_synthetic_message(bus, reply); if (r < 0) return r; bus->rqueue[bus->rqueue_size++] = reply; } else if (hint_sync_call) { struct kdbus_msg *k; k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + m->kdbus->offset_reply); assert(k); if (k->payload_type == KDBUS_PAYLOAD_DBUS) { r = bus_kernel_make_message(bus, k); if (r < 0) { close_kdbus_msg(bus, k); /* Anybody can send us invalid messages, let's just drop them. */ if (r == -EBADMSG || r == -EPROTOTYPE) log_debug("Ignoring invalid message: %s", strerror(-r)); else return r; } } else { log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type); close_kdbus_msg(bus, k); } } return 1; } static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) { _cleanup_bus_message_unref_ sd_bus_message *m = NULL; int r; assert(bus); r = sd_bus_message_new_signal( bus, &m, "/org/freedesktop/DBus", "org.freedesktop.DBus", "NameOwnerChanged"); if (r < 0) return r; r = sd_bus_message_append(m, "sss", name, old_owner, new_owner); if (r < 0) return r; m->sender = "org.freedesktop.DBus"; r = bus_seal_synthetic_message(bus, m); if (r < 0) return r; bus->rqueue[bus->rqueue_size++] = m; m = NULL; return 1; } static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) { char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX]; assert(bus); assert(k); assert(d); if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) old_owner[0] = 0; else sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old_id.id); if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new_id.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) { if (isempty(old_owner)) return 0; new_owner[0] = 0; } else sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new_id.id); return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner); } static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) { char owner[UNIQUE_NAME_MAX]; assert(bus); assert(k); assert(d); sprintf(owner, ":1.%llu", d->id_change.id); return push_name_owner_changed( bus, owner, d->type == KDBUS_ITEM_ID_ADD ? NULL : owner, d->type == KDBUS_ITEM_ID_ADD ? owner : NULL); } static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) { _cleanup_bus_message_unref_ sd_bus_message *m = NULL; int r; assert(bus); assert(k); assert(d); r = bus_message_new_synthetic_error( bus, k->cookie_reply, d->type == KDBUS_ITEM_REPLY_TIMEOUT ? &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call timed out") : &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call peer died"), &m); if (r < 0) return r; m->sender = "org.freedesktop.DBus"; r = bus_seal_synthetic_message(bus, m); if (r < 0) return r; bus->rqueue[bus->rqueue_size++] = m; m = NULL; return 1; } static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) { struct kdbus_item *d, *found = NULL; static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = { [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change, [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change, [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change, [KDBUS_ITEM_ID_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change, [KDBUS_ITEM_ID_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change, [KDBUS_ITEM_REPLY_TIMEOUT - _KDBUS_ITEM_KERNEL_BASE] = translate_reply, [KDBUS_ITEM_REPLY_DEAD - _KDBUS_ITEM_KERNEL_BASE] = translate_reply, }; assert(bus); assert(k); assert(k->payload_type == KDBUS_PAYLOAD_KERNEL); KDBUS_ITEM_FOREACH(d, k, items) { if (d->type >= _KDBUS_ITEM_KERNEL_BASE && d->type < _KDBUS_ITEM_KERNEL_BASE + ELEMENTSOF(translate)) { if (found) return -EBADMSG; found = d; } else log_debug("Got unknown field from kernel %llu", d->type); } if (!found) { log_debug("Didn't find a kernel message to translate."); return 0; } return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found); } int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) { struct kdbus_cmd_recv recv = {}; struct kdbus_msg *k; int r; assert(bus); r = bus_rqueue_make_room(bus); if (r < 0) return r; if (hint_priority) { recv.flags |= KDBUS_RECV_USE_PRIORITY; recv.priority = priority; } r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &recv); if (r < 0) { if (errno == EAGAIN) return 0; return -errno; } k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + recv.offset); if (k->payload_type == KDBUS_PAYLOAD_DBUS) { r = bus_kernel_make_message(bus, k); /* Anybody can send us invalid messages, let's just drop them. */ if (r == -EBADMSG || r == -EPROTOTYPE) { log_debug("Ignoring invalid message: %s", strerror(-r)); r = 0; } } else if (k->payload_type == KDBUS_PAYLOAD_KERNEL) r = bus_kernel_translate_message(bus, k); else { log_debug("Ignoring message with unknown payload type %llu.", (unsigned long long) k->payload_type); r = 0; } if (r <= 0) close_kdbus_msg(bus, k); return r < 0 ? r : 1; } int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated) { struct memfd_cache *c; int fd; assert(address); assert(mapped); assert(allocated); if (!bus || !bus->is_kernel) return -ENOTSUP; assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0); if (bus->n_memfd_cache <= 0) { int r; assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0); r = memfd_new(bus->description); if (r < 0) return r; *address = NULL; *mapped = 0; *allocated = 0; return r; } c = &bus->memfd_cache[--bus->n_memfd_cache]; assert(c->fd >= 0); assert(c->mapped == 0 || c->address); *address = c->address; *mapped = c->mapped; *allocated = c->allocated; fd = c->fd; assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0); return fd; } static void close_and_munmap(int fd, void *address, size_t size) { if (size > 0) assert_se(munmap(address, PAGE_ALIGN(size)) >= 0); safe_close(fd); } void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t mapped, size_t allocated) { struct memfd_cache *c; uint64_t max_mapped = PAGE_ALIGN(MEMFD_CACHE_ITEM_SIZE_MAX); assert(fd >= 0); assert(mapped == 0 || address); if (!bus || !bus->is_kernel) { close_and_munmap(fd, address, mapped); return; } assert_se(pthread_mutex_lock(&bus->memfd_cache_mutex) >= 0); if (bus->n_memfd_cache >= ELEMENTSOF(bus->memfd_cache)) { assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0); close_and_munmap(fd, address, mapped); return; } c = &bus->memfd_cache[bus->n_memfd_cache++]; c->fd = fd; c->address = address; /* If overly long, let's return a bit to the OS */ if (mapped > max_mapped) { assert_se(memfd_set_size(fd, max_mapped) >= 0); assert_se(munmap((uint8_t*) address + max_mapped, PAGE_ALIGN(mapped - max_mapped)) >= 0); c->mapped = c->allocated = max_mapped; } else { c->mapped = mapped; c->allocated = allocated; } assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0); } void bus_kernel_flush_memfd(sd_bus *b) { unsigned i; assert(b); for (i = 0; i < b->n_memfd_cache; i++) close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped); } int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) { uint64_t f = 0; assert(kdbus_flags); if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT) f |= KDBUS_NAME_ALLOW_REPLACEMENT; if (flags & SD_BUS_NAME_REPLACE_EXISTING) f |= KDBUS_NAME_REPLACE_EXISTING; if (flags & SD_BUS_NAME_QUEUE) f |= KDBUS_NAME_QUEUE; *kdbus_flags = f; return 0; } int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) { uint64_t m = 0; assert(kdbus_mask); if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID)) m |= KDBUS_ATTACH_CREDS; if (mask & SD_BUS_CREDS_COMM) m |= KDBUS_ATTACH_PID_COMM; if (mask & SD_BUS_CREDS_TID_COMM) m |= KDBUS_ATTACH_TID_COMM; if (mask & SD_BUS_CREDS_EXE) m |= KDBUS_ATTACH_EXE; if (mask & SD_BUS_CREDS_CMDLINE) m |= KDBUS_ATTACH_CMDLINE; 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)) m |= KDBUS_ATTACH_CGROUP; if (mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS)) m |= KDBUS_ATTACH_CAPS; if (mask & SD_BUS_CREDS_SELINUX_CONTEXT) m |= KDBUS_ATTACH_SECLABEL; if (mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID)) m |= KDBUS_ATTACH_AUDIT; if (mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) m |= KDBUS_ATTACH_NAMES; if (mask & SD_BUS_CREDS_DESCRIPTION) m |= KDBUS_ATTACH_CONN_DESCRIPTION; *kdbus_mask = m; return 0; } int bus_kernel_create_bus(const char *name, bool world, char **s) { struct kdbus_cmd_make *make; struct kdbus_item *n; int fd; assert(name); assert(s); fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC); if (fd < 0) return -errno; make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) + offsetof(struct kdbus_item, data64) + sizeof(uint64_t) + offsetof(struct kdbus_item, str) + DECIMAL_STR_MAX(uid_t) + 1 + strlen(name) + 1), 8); make->size = offsetof(struct kdbus_cmd_make, items); n = make->items; n->size = offsetof(struct kdbus_item, bloom_parameter) + sizeof(struct kdbus_bloom_parameter); n->type = KDBUS_ITEM_BLOOM_PARAMETER; n->bloom_parameter.size = DEFAULT_BLOOM_SIZE; n->bloom_parameter.n_hash = DEFAULT_BLOOM_N_HASH; assert_cc(DEFAULT_BLOOM_SIZE > 0); assert_cc(DEFAULT_BLOOM_N_HASH > 0); make->size += ALIGN8(n->size); n = KDBUS_ITEM_NEXT(n); sprintf(n->str, UID_FMT "-%s", getuid(), name); n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1; n->type = KDBUS_ITEM_MAKE_NAME; make->size += ALIGN8(n->size); make->flags = world ? KDBUS_MAKE_ACCESS_WORLD : 0; if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) { safe_close(fd); return -errno; } if (s) { char *p; p = strjoin("/dev/kdbus/", n->str, "/bus", NULL); if (!p) { safe_close(fd); return -ENOMEM; } *s = p; } return fd; } static int bus_kernel_translate_access(BusPolicyAccess access) { assert(access >= 0); assert(access < _BUS_POLICY_ACCESS_MAX); switch (access) { case BUS_POLICY_ACCESS_SEE: return KDBUS_POLICY_SEE; case BUS_POLICY_ACCESS_TALK: return KDBUS_POLICY_TALK; case BUS_POLICY_ACCESS_OWN: return KDBUS_POLICY_OWN; default: assert_not_reached("Unknown policy access"); } } static int bus_kernel_translate_policy(const BusNamePolicy *policy, struct kdbus_item *item) { int r; assert(policy); assert(item); switch (policy->type) { case BUSNAME_POLICY_TYPE_USER: { const char *user = policy->name; uid_t uid; r = get_user_creds(&user, &uid, NULL, NULL, NULL); if (r < 0) return r; item->policy_access.type = KDBUS_POLICY_ACCESS_USER; item->policy_access.id = uid; break; } case BUSNAME_POLICY_TYPE_GROUP: { const char *group = policy->name; gid_t gid; r = get_group_creds(&group, &gid); if (r < 0) return r; item->policy_access.type = KDBUS_POLICY_ACCESS_GROUP; item->policy_access.id = gid; break; } default: assert_not_reached("Unknown policy type"); } item->policy_access.access = bus_kernel_translate_access(policy->access); return 0; } int bus_kernel_open_bus_fd(const char *bus, char **path) { char *p; int fd; size_t len; len = strlen("/dev/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1; if (path) { p = malloc(len); if (!p) return -ENOMEM; *path = p; } else p = alloca(len); sprintf(p, "/dev/kdbus/" UID_FMT "-%s/bus", getuid(), bus); fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC); if (fd < 0) return -errno; return fd; } int bus_kernel_create_endpoint(const char *bus_name, const char *ep_name, char **ep_path) { _cleanup_free_ char *path = NULL; struct kdbus_cmd_make *make; struct kdbus_item *n; size_t size; int fd; fd = bus_kernel_open_bus_fd(bus_name, &path); if (fd < 0) return fd; size = ALIGN8(offsetof(struct kdbus_cmd_make, items)); size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(ep_name) + 1); make = alloca0_align(size, 8); make->size = size; make->flags = KDBUS_MAKE_ACCESS_WORLD; n = make->items; n->type = KDBUS_ITEM_MAKE_NAME; n->size = offsetof(struct kdbus_item, str) + strlen(ep_name) + 1; strcpy(n->str, ep_name); if (ioctl(fd, KDBUS_CMD_ENDPOINT_MAKE, make) < 0) { safe_close(fd); return -errno; } if (ep_path) { char *p; p = strjoin(dirname(path), "/", ep_name, NULL); if (!p) { safe_close(fd); return -ENOMEM; } *ep_path = p; } return fd; } int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep) { struct kdbus_cmd_update *update; struct kdbus_item *n; BusEndpointPolicy *po; Iterator i; size_t size; int r; size = ALIGN8(offsetof(struct kdbus_cmd_update, items)); HASHMAP_FOREACH(po, ep->policy_hash, i) { size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(po->name) + 1); size += ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access)); } update = alloca0_align(size, 8); update->size = size; n = update->items; HASHMAP_FOREACH(po, ep->policy_hash, i) { n->type = KDBUS_ITEM_NAME; n->size = offsetof(struct kdbus_item, str) + strlen(po->name) + 1; strcpy(n->str, po->name); n = KDBUS_ITEM_NEXT(n); n->type = KDBUS_ITEM_POLICY_ACCESS; n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access); n->policy_access.type = KDBUS_POLICY_ACCESS_USER; n->policy_access.access = bus_kernel_translate_access(po->access); n->policy_access.id = uid; n = KDBUS_ITEM_NEXT(n); } r = ioctl(fd, KDBUS_CMD_ENDPOINT_UPDATE, update); if (r < 0) return -errno; return 0; } int bus_kernel_make_starter( int fd, const char *name, bool activating, bool accept_fd, BusNamePolicy *policy, BusPolicyAccess world_policy) { struct kdbus_cmd_hello *hello; struct kdbus_item *n; size_t policy_cnt = 0; BusNamePolicy *po; size_t size; int r; assert(fd >= 0); assert(name); LIST_FOREACH(policy, po, policy) policy_cnt++; if (world_policy >= 0) policy_cnt++; size = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) + ALIGN8(offsetof(struct kdbus_item, str) + strlen(name) + 1) + policy_cnt * ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access)); hello = alloca0_align(size, 8); n = hello->items; strcpy(n->str, name); n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1; n->type = KDBUS_ITEM_NAME; n = KDBUS_ITEM_NEXT(n); LIST_FOREACH(policy, po, policy) { n->type = KDBUS_ITEM_POLICY_ACCESS; n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access); r = bus_kernel_translate_policy(po, n); if (r < 0) return r; n = KDBUS_ITEM_NEXT(n); } if (world_policy >= 0) { n->type = KDBUS_ITEM_POLICY_ACCESS; n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access); n->policy_access.type = KDBUS_POLICY_ACCESS_WORLD; n->policy_access.access = bus_kernel_translate_access(world_policy); } hello->size = size; hello->flags = (activating ? KDBUS_HELLO_ACTIVATOR : KDBUS_HELLO_POLICY_HOLDER) | (accept_fd ? KDBUS_HELLO_ACCEPT_FD : 0); hello->pool_size = KDBUS_POOL_SIZE; hello->attach_flags_send = _KDBUS_ATTACH_ANY; hello->attach_flags_recv = _KDBUS_ATTACH_ALL; if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0) return -errno; /* The higher 32bit of the bus_flags fields are considered * 'incompatible flags'. Refuse them all for now. */ if (hello->bus_flags > 0xFFFFFFFFULL) return -ENOTSUP; if (!bloom_validate_parameters((size_t) hello->bloom.size, (unsigned) hello->bloom.n_hash)) return -ENOTSUP; return fd; } int bus_kernel_create_domain(const char *name, char **s) { struct kdbus_cmd_make *make; struct kdbus_item *n; int fd; assert(name); assert(s); fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC); if (fd < 0) return -errno; make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) + offsetof(struct kdbus_item, str) + strlen(name) + 1), 8); n = make->items; strcpy(n->str, name); n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1; n->type = KDBUS_ITEM_MAKE_NAME; make->size = ALIGN8(offsetof(struct kdbus_cmd_make, items) + n->size); make->flags = KDBUS_MAKE_ACCESS_WORLD; if (ioctl(fd, KDBUS_CMD_DOMAIN_MAKE, make) < 0) { safe_close(fd); return -errno; } /* The higher 32bit of the flags field are considered * 'incompatible flags'. Refuse them all for now. */ if (make->flags > 0xFFFFFFFFULL) { safe_close(fd); return -ENOTSUP; } if (s) { char *p; p = strappend("/dev/kdbus/domain/", name); if (!p) { safe_close(fd); return -ENOMEM; } *s = p; } return fd; } int bus_kernel_try_close(sd_bus *bus) { assert(bus); assert(bus->is_kernel); if (ioctl(bus->input_fd, KDBUS_CMD_BYEBYE) < 0) return -errno; return 0; } int bus_kernel_drop_one(int fd) { struct kdbus_cmd_recv recv = { .flags = KDBUS_RECV_DROP }; assert(fd >= 0); if (ioctl(fd, KDBUS_CMD_MSG_RECV, &recv) < 0) return -errno; return 0; }