diff options
Diffstat (limited to 'src/libsystemd/sd-bus/bus-kernel.c')
| -rw-r--r-- | src/libsystemd/sd-bus/bus-kernel.c | 1348 |
1 files changed, 1348 insertions, 0 deletions
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c new file mode 100644 index 0000000000..f85b4d5676 --- /dev/null +++ b/src/libsystemd/sd-bus/bus-kernel.c @@ -0,0 +1,1348 @@ +/*-*- 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 <http://www.gnu.org/licenses/>. +***/ + +#ifdef HAVE_VALGRIND_MEMCHECK_H +#include <valgrind/memcheck.h> +#endif + +#include <fcntl.h> +#include <malloc.h> +#include <sys/mman.h> + +#include "util.h" +#include "strv.h" + +#include "bus-internal.h" +#include "bus-message.h" +#include "bus-kernel.h" +#include "bus-bloom.h" +#include "bus-util.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 void* append_bloom(struct kdbus_item **d, size_t length) { + void *r; + + assert(d); + + *d = ALIGN8_PTR(*d); + + (*d)->size = offsetof(struct kdbus_item, data) + length; + (*d)->type = KDBUS_ITEM_BLOOM; + r = (*d)->data; + + *d = (struct kdbus_item *) ((uint8_t*) *d + (*d)->size); + + return r; +} + +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, void *bloom) { + unsigned i; + int r; + + assert(m); + assert(bloom); + + memset(bloom, 0, BLOOM_SIZE); + + bloom_add_pair(bloom, "message-type", bus_message_type_to_string(m->header->type)); + + if (m->interface) + bloom_add_pair(bloom, "interface", m->interface); + if (m->member) + bloom_add_pair(bloom, "member", m->member); + if (m->path) { + bloom_add_pair(bloom, "path", m->path); + bloom_add_pair(bloom, "path-slash-prefix", m->path); + bloom_add_prefixes(bloom, "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(bloom, buf, t); + + strcpy(e, "-dot-prefix"); + bloom_add_prefixes(bloom, buf, t, '.'); + strcpy(e, "-slash-prefix"); + bloom_add_prefixes(bloom, 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; + bool well_known; + uint64_t unique; + size_t sz, dl; + unsigned i; + int r; + + assert(b); + assert(m); + assert(m->sealed); + + if (m->kdbus) + return 0; + + if (m->destination) { + r = bus_kernel_parse_unique_name(m->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, data) + BLOOM_SIZE); + + /* Add in well-known destination header */ + if (well_known) { + dl = strlen(m->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; + memset(m->kdbus, 0, 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); + m->kdbus->dst_id = + well_known ? 0 : + m->destination ? unique : KDBUS_DST_ID_BROADCAST; + m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS; + m->kdbus->cookie = m->header->serial; + + if (m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + m->kdbus->cookie_reply = m->reply_cookie; + else + m->kdbus->timeout_ns = m->timeout * NSEC_PER_USEC; + + d = m->kdbus->items; + + if (well_known) + append_destination(&d, m->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 && m->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) { + void *p; + + p = append_bloom(&d, BLOOM_SIZE); + r = bus_message_setup_bloom(m, p); + 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 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: + m->realtime = d->timestamp.realtime_ns / NSEC_PER_USEC; + m->monotonic = d->timestamp.monotonic_ns / NSEC_PER_USEC; + 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; + + if (!bus->cgroup_root) { + r = cg_get_root_path(&bus->cgroup_root); + 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 = d->data; + m->creds.capability_size = l; + 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_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_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: + if (m) { + struct bus_body_part *part; + unsigned i; + + /* Make sure the memfds are not freed twice */ + MESSAGE_FOREACH_PART(part, i, m) + if (part->memfd >= 0) + part->memfd = -1; + + sd_bus_message_unref(m); + } + + return r; +} + +int bus_kernel_take_fd(sd_bus *b) { + struct kdbus_cmd_hello *hello; + struct kdbus_item *item; + size_t l = 0, sz; + int r; + + assert(b); + + if (b->is_server) + return -EINVAL; + + b->use_memfd = 1; + + sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items)); + + 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(sz); + hello->size = sz; + hello->conn_flags = b->hello_flags; + hello->attach_flags = b->attach_flags; + hello->pool_size = KDBUS_POOL_SIZE; + + item = hello->items; + + 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; + 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 both flags fields are considered + * 'incompatible flags'. Refuse them all for now. */ + if (hello->bus_flags > 0xFFFFFFFFULL || + hello->conn_flags > 0xFFFFFFFFULL) + return -ENOTSUP; + + if (hello->bloom_size != BLOOM_SIZE) + return -ENOTSUP; + + 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->conn_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); +} + +int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) { + 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; + + 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; + + return 0; + } + + return 1; +} + +static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) { + uint64_t off; + struct kdbus_item *d; + + assert(bus); + assert(k); + + off = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer; + ioctl(bus->input_fd, KDBUS_CMD_FREE, &off); + + 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) + close_nointr_nofail(d->memfd.fd); + } +} + +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, + "/org/freedesktop/DBus", + "org.freedesktop.DBus", + "NameOwnerChanged", + &m); + 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.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); + + if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new.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); + + 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) { + struct kdbus_cmd_recv recv = {}; + struct kdbus_msg *k; + int r; + + assert(bus); + + r = bus_rqueue_make_room(bus); + if (r < 0) + return r; + + 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 + 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) { + struct kdbus_cmd_memfd_make cmd = { + .size = sizeof(struct kdbus_cmd_memfd_make), + }; + int r; + + assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0); + + r = ioctl(bus->input_fd, KDBUS_CMD_MEMFD_NEW, &cmd); + if (r < 0) + return -errno; + + *address = NULL; + *mapped = 0; + *allocated = 0; + return cmd.fd; + } + + 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); + + close_nointr_nofail(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(ioctl(fd, KDBUS_CMD_MEMFD_SIZE_SET, &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|SD_BUS_CREDS_TID_COMM)) + m |= KDBUS_ATTACH_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; + + *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(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)); + + make->size = offsetof(struct kdbus_cmd_make, items); + + n = make->items; + n->size = offsetof(struct kdbus_item, data64) + sizeof(uint64_t); + n->type = KDBUS_ITEM_BLOOM_SIZE; + n->data64[0] = BLOOM_SIZE; + assert_cc(BLOOM_SIZE % 8 == 0); + make->size += ALIGN8(n->size); + + n = KDBUS_ITEM_NEXT(n); + sprintf(n->str, "%lu-%s", (unsigned long) 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 = KDBUS_MAKE_POLICY_OPEN | (world ? KDBUS_MAKE_ACCESS_WORLD : 0); + + if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + /* The higher 32bit of the flags field are considered + * 'incompatible flags'. Refuse them all for now. */ + if (make->flags > 0xFFFFFFFFULL) { + close_nointr_nofail(fd); + return -ENOTSUP; + } + + if (s) { + char *p; + + p = strjoin("/dev/kdbus/", n->str, "/bus", NULL); + if (!p) { + close_nointr_nofail(fd); + return -ENOMEM; + } + + *s = p; + } + + return fd; +} + +int bus_kernel_create_starter(const char *bus, const char *name) { + struct kdbus_cmd_hello *hello; + struct kdbus_item *n; + char *p; + int fd; + + assert(bus); + assert(name); + + p = alloca(sizeof("/dev/kdbus/") - 1 + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + sizeof("/bus")); + sprintf(p, "/dev/kdbus/%lu-%s/bus", (unsigned long) getuid(), bus); + + fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return -errno; + + hello = alloca0(ALIGN8(offsetof(struct kdbus_cmd_hello, items) + + offsetof(struct kdbus_item, str) + + strlen(name) + 1)); + + n = hello->items; + strcpy(n->str, name); + n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1; + n->type = KDBUS_ITEM_NAME; + + hello->size = ALIGN8(offsetof(struct kdbus_cmd_hello, items) + n->size); + hello->conn_flags = KDBUS_HELLO_ACTIVATOR; + hello->pool_size = KDBUS_POOL_SIZE; + + if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + /* The higher 32bit of both flags fields are considered + * 'incompatible flags'. Refuse them all for now. */ + if (hello->bus_flags > 0xFFFFFFFFULL || + hello->conn_flags > 0xFFFFFFFFULL) { + close_nointr_nofail(fd); + return -ENOTSUP; + } + + if (hello->bloom_size != BLOOM_SIZE) { + close_nointr_nofail(fd); + return -ENOTSUP; + } + + return fd; +} + +int bus_kernel_create_namespace(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(ALIGN8(offsetof(struct kdbus_cmd_make, items) + + offsetof(struct kdbus_item, str) + + strlen(name) + 1)); + + 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_POLICY_OPEN | KDBUS_MAKE_ACCESS_WORLD; + + if (ioctl(fd, KDBUS_CMD_NS_MAKE, make) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + /* The higher 32bit of the flags field are considered + * 'incompatible flags'. Refuse them all for now. */ + if (make->flags > 0xFFFFFFFFULL) { + close_nointr_nofail(fd); + return -ENOTSUP; + } + + if (s) { + char *p; + + p = strappend("/dev/kdbus/ns/", name); + if (!p) { + close_nointr_nofail(fd); + return -ENOMEM; + } + + *s = p; + } + + return fd; +} + +int bus_kernel_create_monitor(const char *bus) { + struct kdbus_cmd_hello *hello; + char *p; + int fd; + + assert(bus); + + p = alloca(sizeof("/dev/kdbus/") - 1 + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + sizeof("/bus")); + sprintf(p, "/dev/kdbus/%lu-%s/bus", (unsigned long) getuid(), bus); + + fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return -errno; + + hello = alloca0(sizeof(struct kdbus_cmd_hello)); + hello->size = sizeof(struct kdbus_cmd_hello); + hello->conn_flags = KDBUS_HELLO_ACTIVATOR; + hello->pool_size = KDBUS_POOL_SIZE; + + if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + /* The higher 32bit of both flags fields are considered + * 'incompatible flags'. Refuse them all for now. */ + if (hello->bus_flags > 0xFFFFFFFFULL || + hello->conn_flags > 0xFFFFFFFFULL) { + close_nointr_nofail(fd); + return -ENOTSUP; + } + + 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; +} |