picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity
Systemd/src/libsystemd-bus/bus-kernel.c
Lennart Poettering 693eb9a2d4 bus: rename message "serial" to "cookie" 
Even if the lower-leveld dbus1 protocol calls it "serial", let's expose
the word "cookie" for this instead, as this is what kdbus uses and since
it doesn't imply monotonicity the same way "serial" does.
2013-12-25 18:04:04 +01:00

1340 lines
43 KiB
C
Raw Blame History

/*-*- 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;
}
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);
}
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:
destination = d->str;
break;
case KDBUS_ITEM_NAME:
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_read_message(sd_bus *bus) {
struct kdbus_msg *k;
uint64_t off;
int r;
assert(bus);
r = bus_rqueue_make_room(bus);
if (r < 0)
return r;
r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &off);
if (r < 0) {
if (errno == EAGAIN)
return 0;
return -errno;
}
k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + off);
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) {
int r;
assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
r = ioctl(bus->input_fd, KDBUS_CMD_MEMFD_NEW, &fd);
if (r < 0)
return -errno;
*address = NULL;
*mapped = 0;
*allocated = 0;
return 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, 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;
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;
}
Reference in a new issue View git blame Copy permalink