diff options
Diffstat (limited to 'src/libcore/bus-policy.c')
| -rw-r--r-- | src/libcore/bus-policy.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/src/libcore/bus-policy.c b/src/libcore/bus-policy.c new file mode 100644 index 0000000000..4907c268e8 --- /dev/null +++ b/src/libcore/bus-policy.c @@ -0,0 +1,180 @@ +/*** + 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); |