/*-*- 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 "cgroup-util.h"
#include "fileio.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"
#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 void add_bloom_arg(void *data, size_t size, unsigned n_hash, unsigned i, const char *t) {
char buf[sizeof("arg")-1 + 2 + sizeof("-slash-prefix")];
char *e;
assert(data);
assert(size > 0);
assert(i < 64);
assert(t);
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, size, n_hash, buf, t);
strcpy(e, "-dot-prefix");
bloom_add_prefixes(data, size, n_hash, buf, t, '.');
strcpy(e, "-slash-prefix");
bloom_add_prefixes(data, size, n_hash, buf, t, '/');
}
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++) {
const char *t, *contents;
char type;
r = sd_bus_message_peek_type(m, &type, &contents);
if (r < 0)
return r;
if (IN_SET(type, SD_BUS_TYPE_STRING, SD_BUS_TYPE_OBJECT_PATH, SD_BUS_TYPE_SIGNATURE)) {
/* The bloom filter includes simple strings of any kind */
r = sd_bus_message_read_basic(m, type, &t);
if (r < 0)
return r;
add_bloom_arg(data, m->bus->bloom_size, m->bus->bloom_n_hash, i, t);
} if (type == SD_BUS_TYPE_ARRAY && STR_IN_SET(contents, "s", "o", "g")) {
/* As well as array of simple strings of any kinds */
r = sd_bus_message_enter_container(m, type, contents);
if (r < 0)
return r;
while ((r = sd_bus_message_read_basic(m, contents[0], &t)) > 0)
add_bloom_arg(data, m->bus->bloom_size, m->bus->bloom_n_hash, i, t);
if (r < 0)
return r;
r = sd_bus_message_exit_container(m);
if (r < 0)
return r;
} else
/* Stop adding to bloom filter as soon as we
* run into the first argument we cannot add
* to it. */
break;
}
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 bus_message_set_sender_driver(sd_bus *bus, sd_bus_message *m) {
assert(bus);
assert(m);
m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus";
m->creds.well_known_names_driver = true;
m->creds.mask |= (SD_BUS_CREDS_UNIQUE_NAME|SD_BUS_CREDS_WELL_KNOWN_NAMES) & bus->creds_mask;
}
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 *)bus->kdbus_buffer + 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 *)bus->kdbus_buffer + d->vec.offset;
part->size = d->vec.size;
} else {
if (!part->is_zero)
part->data = (uint8_t *)bus->kdbus_buffer + 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_PIDS:
/* The PID starttime/TID might be missing,
* 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->pids.pid > 0) {
m->creds.pid = (pid_t) d->pids.pid;
m->creds.mask |= SD_BUS_CREDS_PID & bus->creds_mask;
}
if (d->pids.starttime > 0) {
m->creds.pid_starttime = d->pids.starttime / NSEC_PER_USEC;
m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask;
}
if (d->pids.tid > 0) {
m->creds.tid = (pid_t) d->pids.tid;
m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask;
}
break;
case KDBUS_ITEM_CREDS:
/* EUID/SUID/FSUID/EGID/SGID/FSGID might be missing too (see above). */
if ((uid_t) d->creds.uid != UID_INVALID) {
m->creds.uid = (uid_t) d->creds.uid;
m->creds.mask |= SD_BUS_CREDS_UID & bus->creds_mask;
}
if ((uid_t) d->creds.euid != UID_INVALID) {
m->creds.euid = (uid_t) d->creds.euid;
m->creds.mask |= SD_BUS_CREDS_EUID & bus->creds_mask;
}
if ((uid_t) d->creds.suid != UID_INVALID) {
m->creds.suid = (uid_t) d->creds.suid;
m->creds.mask |= SD_BUS_CREDS_SUID & bus->creds_mask;
}
if ((uid_t) d->creds.fsuid != UID_INVALID) {
m->creds.fsuid = (uid_t) d->creds.fsuid;
m->creds.mask |= SD_BUS_CREDS_FSUID & bus->creds_mask;
}
if ((gid_t) d->creds.gid != GID_INVALID) {
m->creds.gid = (gid_t) d->creds.gid;
m->creds.mask |= SD_BUS_CREDS_GID & bus->creds_mask;
}
if ((gid_t) d->creds.egid != GID_INVALID) {
m->creds.egid = (gid_t) d->creds.egid;
m->creds.mask |= SD_BUS_CREDS_EGID & bus->creds_mask;
}
if ((gid_t) d->creds.sgid != GID_INVALID) {
m->creds.sgid = (gid_t) d->creds.sgid;
m->creds.mask |= SD_BUS_CREDS_SGID & bus->creds_mask;
}
if ((gid_t) d->creds.fsgid != GID_INVALID) {
m->creds.fsgid = (gid_t) d->creds.fsgid;
m->creds.mask |= SD_BUS_CREDS_FSGID & 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:
if ((uint32_t) d->audit.sessionid != (uint32_t) -1) {
m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
m->creds.mask |= SD_BUS_CREDS_AUDIT_SESSION_ID & bus->creds_mask;
}
if ((uid_t) d->audit.loginuid != UID_INVALID) {
m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
m->creds.mask |= 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)) {
r = -EBADMSG;
goto fail;
}
destination = d->str;
break;
case KDBUS_ITEM_OWNED_NAME:
if (!service_name_is_valid(d->name.name)) {
r = -EBADMSG;
goto fail;
}
if (bus->creds_mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) {
char **wkn;
size_t n;
/* We just extend the array here, but
* do not allocate the strings inside
* of it, instead we just point to our
* buffer directly. */
n = strv_length(m->creds.well_known_names);
wkn = realloc(m->creds.well_known_names, (n + 2) * sizeof(char*));
if (!wkn) {
r = -ENOMEM;
goto fail;
}
wkn[n] = d->name.name;
wkn[n+1] = NULL;
m->creds.well_known_names = wkn;
m->creds.mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES;
}
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_AUXGROUPS:
if (bus->creds_mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS) {
assert_cc(sizeof(gid_t) == sizeof(uint32_t));
m->creds.n_supplementary_gids = (d->size - offsetof(struct kdbus_item, data32)) / sizeof(uint32_t);
m->creds.supplementary_gids = (gid_t*) d->data32;
m->creds.mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS;
}
break;
case KDBUS_ITEM_FDS:
case KDBUS_ITEM_SECLABEL:
break;
default:
log_debug("Got unknown field from kernel %llu", d->type);
}
}
/* If we requested the list of well-known names to be appended
* and the sender had none no item for it will be
* attached. However, this does *not* mean that we the kernel
* didn't want to provide this information to us. Hence, let's
* explicitly mark this information as available if it was
* requested. */
m->creds.mask |= bus->creds_mask & SD_BUS_CREDS_WELL_KNOWN_NAMES;
r = bus_message_parse_fields(m);
if (r < 0)
goto fail;
/* Refuse messages if kdbus and dbus1 cookie doesn't match up */
if ((uint64_t) m->header->serial != k->cookie) {
r = -EBADMSG;
goto fail;
}
/* Refuse messages where the reply flag doesn't match up */
if (!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) != !!(k->flags & KDBUS_MSG_FLAGS_EXPECT_REPLY)) {
r = -EBADMSG;
goto fail;
}
/* Refuse reply messages where the reply cookie doesn't match up */
if ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) && m->reply_cookie != k->cookie_reply) {
r = -EBADMSG;
goto fail;
}
/* Refuse messages where the autostart flag doesn't match up */
if (!(m->header->flags & BUS_MESSAGE_NO_AUTO_START) != !(k->flags & KDBUS_MSG_FLAGS_NO_AUTO_START)) {
r = -EBADMSG;
goto fail;
}
/* Override information from the user header with data from the kernel */
if (k->src_id == KDBUS_SRC_ID_KERNEL)
bus_message_set_sender_driver(bus, m);
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_pids_valid)
sz += ALIGN8(offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids));
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_pids_valid) {
item->size = offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids);
item->type = KDBUS_ITEM_PIDS;
item->pids = b->fake_pids;
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);
}
int bus_kernel_cmd_free(sd_bus *bus, uint64_t offset) {
struct kdbus_cmd_free cmd = {
.flags = 0,
.offset = offset,
};
int r;
assert(bus);
assert(bus->is_kernel);
r = ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd);
if (r < 0)
return -errno;
return 0;
}
static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
struct kdbus_item *d;
assert(bus);
assert(k);
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);
}
bus_kernel_cmd_free(bus, (uint8_t*) k - (uint8_t*) bus->kdbus_buffer);
}
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_errno(r, "Ignoring invalid message: %m");
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;
bus_message_set_sender_driver(bus, m);
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;
bus_message_set_sender_driver(bus, m);
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;
if (errno == EOVERFLOW) {
log_debug("%s: kdbus reports %" PRIu64 " dropped broadcast messages, ignoring.", strna(bus->description), (uint64_t) recv.dropped_msgs);
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_errno(r, "Ignoring invalid message: %m");
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);
}
uint64_t request_name_flags_to_kdbus(uint64_t flags) {
uint64_t f = 0;
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;
return f;
}
uint64_t attach_flags_to_kdbus(uint64_t mask) {
uint64_t m = 0;
if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID))
m |= KDBUS_ATTACH_CREDS;
if (mask & (SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
m |= KDBUS_ATTACH_PIDS;
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;
if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
m |= KDBUS_ATTACH_AUXGROUPS;
return m;
}
int bus_kernel_create_bus(const char *name, bool world, char **s) {
struct kdbus_cmd_make *make;
struct kdbus_item *n;
size_t l;
int fd;
assert(name);
assert(s);
fd = open("/sys/fs/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
if (fd < 0)
return -errno;
l = strlen(name);
make = alloca0_align(offsetof(struct kdbus_cmd_make, items) +
ALIGN8(offsetof(struct kdbus_item, bloom_parameter) + sizeof(struct kdbus_bloom_parameter)) +
ALIGN8(offsetof(struct kdbus_item, data64) + sizeof(uint64_t)) +
ALIGN8(offsetof(struct kdbus_item, str) + DECIMAL_STR_MAX(uid_t) + 1 + l + 1),
8);
make->size = offsetof(struct kdbus_cmd_make, items);
/* Set the bloom parameters */
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);
/* The busses we create make no restrictions on what metadata
* peers can read from incoming messages. */
n = KDBUS_ITEM_NEXT(n);
n->type = KDBUS_ITEM_ATTACH_FLAGS_RECV;
n->size = offsetof(struct kdbus_item, data64) + sizeof(uint64_t);
n->data64[0] = _KDBUS_ATTACH_ANY;
make->size += ALIGN8(n->size);
/* Set the a good name */
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("/sys/fs/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;
assert(bus);
len = strlen("/sys/fs/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
if (path) {
p = new(char, len);
if (!p)
return -ENOMEM;
} else
p = newa(char, len);
sprintf(p, "/sys/fs/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
if (fd < 0) {
if (path)
free(p);
return -errno;
}
if (path)
*path = p;
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;
const char *name;
int fd;
fd = bus_kernel_open_bus_fd(bus_name, &path);
if (fd < 0)
return fd;
make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items)) +
ALIGN8(offsetof(struct kdbus_item, str) + DECIMAL_STR_MAX(uid_t) + 1 + strlen(ep_name) + 1),
8);
make->size = ALIGN8(offsetof(struct kdbus_cmd_make, items));
make->flags = KDBUS_MAKE_ACCESS_WORLD;
n = make->items;
sprintf(n->str, UID_FMT "-%s", getuid(), ep_name);
n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
n->type = KDBUS_ITEM_MAKE_NAME;
make->size += ALIGN8(n->size);
name = n->str;
if (ioctl(fd, KDBUS_CMD_ENDPOINT_MAKE, make) < 0) {
safe_close(fd);
return -errno;
}
if (ep_path) {
char *p;
p = strjoin(dirname(path), "/", 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 = 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_ANY;
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_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;
}
int bus_kernel_realize_attach_flags(sd_bus *bus) {
struct kdbus_cmd_update *update;
struct kdbus_item *n;
assert(bus);
assert(bus->is_kernel);
update = alloca0_align(offsetof(struct kdbus_cmd_update, items) +
ALIGN8(offsetof(struct kdbus_item, data64) + sizeof(uint64_t)),
8);
n = update->items;
n->type = KDBUS_ITEM_ATTACH_FLAGS_RECV;
n->size = offsetof(struct kdbus_item, data64) + sizeof(uint64_t);
n->data64[0] = bus->attach_flags;
update->size =
offsetof(struct kdbus_cmd_update, items) +
ALIGN8(n->size);
if (ioctl(bus->input_fd, KDBUS_CMD_CONN_UPDATE, update) < 0)
return -errno;
return 0;
}
int bus_kernel_fix_attach_mask(void) {
_cleanup_free_ char *mask = NULL;
uint64_t m = (uint64_t) -1;
char buf[2+16+2];
int r;
/* By default we don't want any kdbus metadata fields to be
* suppressed, hence we reset the kernel mask for it to
* (uint64_t) -1. This is overridable via a kernel command
* line option, however. */
r = get_proc_cmdline_key("systemd.kdbus_attach_flags_mask=", &mask);
if (r < 0)
return log_warning_errno(r, "Failed to read kernel command line: %m");
if (mask) {
const char *p = mask;
if (startswith(p, "0x"))
p += 2;
if (sscanf(p, "%" PRIx64, &m) != 1)
log_warning("Couldn't parse systemd.kdbus_attach_flags_mask= kernel command line parameter.");
}
sprintf(buf, "0x%" PRIx64 "\n", m);
r = write_string_file("/sys/module/kdbus/parameters/attach_flags_mask", buf);
if (r < 0)
return log_full_errno(
r == -EROFS ? LOG_DEBUG : LOG_WARNING, r,
"Failed to write kdbus attach mask: %m");
return 0;
}
int bus_kernel_get_bus_name(sd_bus *bus, char **name) {
struct kdbus_cmd_info cmd = {
.size = sizeof(struct kdbus_cmd_info),
};
struct kdbus_info *info;
struct kdbus_item *item;
char *n = NULL;
int r;
assert(bus);
assert(name);
assert(bus->is_kernel);
r = ioctl(bus->input_fd, KDBUS_CMD_BUS_CREATOR_INFO, &cmd);
if (r < 0)
return -errno;
info = (struct kdbus_info*) ((uint8_t*) bus->kdbus_buffer + cmd.offset);
KDBUS_ITEM_FOREACH(item, info, items)
if (item->type == KDBUS_ITEM_MAKE_NAME) {
r = free_and_strdup(&n, item->str);
break;
}
bus_kernel_cmd_free(bus, cmd.offset);
if (r < 0)
return r;
if (!n)
return -EIO;
*name = n;
return 0;
}