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/***
This file is part of systemd.
Copyright 2014 Daniel Mack
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/>.
***/
#include <stdlib.h>
#include "alloc-util.h"
#include "bus-kernel.h"
#include "bus-policy.h"
#include "kdbus.h"
#include "string-table.h"
#include "user-util.h"
#include "util.h"
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");
}
}
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_make_starter(
int fd,
const char *name,
bool activating,
bool accept_fd,
BusNamePolicy *policy,
BusPolicyAccess world_policy) {
struct kdbus_cmd_free cmd_free = { .size = sizeof(cmd_free) };
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) {
if (errno == ENOTTY) /* Major API change */
return -ESOCKTNOSUPPORT;
return -errno;
}
/* not interested in any output values */
cmd_free.offset = hello->offset;
(void) ioctl(fd, KDBUS_CMD_FREE, &cmd_free);
/* The higher 32bit of the bus_flags fields are considered
* 'incompatible flags'. Refuse them all for now. */
if (hello->bus_flags > 0xFFFFFFFFULL)
return -ESOCKTNOSUPPORT;
return fd;
}
static const char* const bus_policy_access_table[_BUS_POLICY_ACCESS_MAX] = {
[BUS_POLICY_ACCESS_SEE] = "see",
[BUS_POLICY_ACCESS_TALK] = "talk",
[BUS_POLICY_ACCESS_OWN] = "own",
};
DEFINE_STRING_TABLE_LOOKUP(bus_policy_access, BusPolicyAccess);
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