bus-xml-policy.c revision 8752c5752f3b9023f9ce96a55d70c6e5fc31118f
/*-*- 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/>.
***/
#include "sd-login.h"
#include "bus-internal.h"
#include "bus-xml-policy.h"
#include "conf-files.h"
#include "fileio.h"
#include "formats-util.h"
#include "locale-util.h"
#include "set.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "xml.h"
static void policy_item_free(PolicyItem *i) {
assert(i);
free(i->interface);
free(i->member);
free(i->error);
free(i->name);
free(i->path);
free(i);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(PolicyItem*, policy_item_free);
static void item_append(PolicyItem *i, PolicyItem **list) {
PolicyItem *tail;
LIST_FIND_TAIL(items, *list, tail);
LIST_INSERT_AFTER(items, *list, tail, i);
}
static int file_load(Policy *p, const char *path) {
_cleanup_free_ char *c = NULL, *policy_user = NULL, *policy_group = NULL;
_cleanup_(policy_item_freep) PolicyItem *i = NULL;
void *xml_state = NULL;
unsigned n_other = 0;
const char *q;
int r;
enum {
STATE_OUTSIDE,
STATE_BUSCONFIG,
STATE_POLICY,
STATE_POLICY_CONTEXT,
STATE_POLICY_CONSOLE,
STATE_POLICY_USER,
STATE_POLICY_GROUP,
STATE_POLICY_OTHER_ATTRIBUTE,
STATE_ALLOW_DENY,
STATE_ALLOW_DENY_INTERFACE,
STATE_ALLOW_DENY_MEMBER,
STATE_ALLOW_DENY_ERROR,
STATE_ALLOW_DENY_PATH,
STATE_ALLOW_DENY_MESSAGE_TYPE,
STATE_ALLOW_DENY_NAME,
STATE_ALLOW_DENY_OTHER_ATTRIBUTE,
STATE_OTHER,
} state = STATE_OUTSIDE;
enum {
POLICY_CATEGORY_NONE,
POLICY_CATEGORY_DEFAULT,
POLICY_CATEGORY_MANDATORY,
POLICY_CATEGORY_ON_CONSOLE,
POLICY_CATEGORY_NO_CONSOLE,
POLICY_CATEGORY_USER,
POLICY_CATEGORY_GROUP
} policy_category = POLICY_CATEGORY_NONE;
unsigned line = 0;
assert(p);
r = read_full_file(path, &c, NULL);
if (r < 0) {
if (r == -ENOENT)
return 0;
if (r == -EISDIR)
return r;
return log_error_errno(r, "Failed to load %s: %m", path);
}
q = c;
for (;;) {
_cleanup_free_ char *name = NULL;
int t;
t = xml_tokenize(&q, &name, &xml_state, &line);
if (t < 0)
return log_error_errno(t, "XML parse failure in %s: %m", path);
switch (state) {
case STATE_OUTSIDE:
if (t == XML_TAG_OPEN) {
if (streq(name, "busconfig"))
state = STATE_BUSCONFIG;
else {
log_error("Unexpected tag %s at %s:%u.", name, path, line);
return -EINVAL;
}
} else if (t == XML_END)
return 0;
else if (t != XML_TEXT || !in_charset(name, WHITESPACE)) {
log_error("Unexpected token (1) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_BUSCONFIG:
if (t == XML_TAG_OPEN) {
if (streq(name, "policy")) {
state = STATE_POLICY;
policy_category = POLICY_CATEGORY_NONE;
free(policy_user);
free(policy_group);
policy_user = policy_group = NULL;
} else {
state = STATE_OTHER;
n_other = 0;
}
} else if (t == XML_TAG_CLOSE_EMPTY ||
(t == XML_TAG_CLOSE && streq(name, "busconfig")))
state = STATE_OUTSIDE;
else if (t != XML_TEXT || !in_charset(name, WHITESPACE)) {
log_error("Unexpected token (2) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY:
if (t == XML_ATTRIBUTE_NAME) {
if (streq(name, "context"))
state = STATE_POLICY_CONTEXT;
else if (streq(name, "at_console"))
state = STATE_POLICY_CONSOLE;
else if (streq(name, "user"))
state = STATE_POLICY_USER;
else if (streq(name, "group"))
state = STATE_POLICY_GROUP;
else {
log_warning("Attribute %s of <policy> tag unknown at %s:%u, ignoring.", name, path, line);
state = STATE_POLICY_OTHER_ATTRIBUTE;
}
} else if (t == XML_TAG_CLOSE_EMPTY ||
(t == XML_TAG_CLOSE && streq(name, "policy")))
state = STATE_BUSCONFIG;
else if (t == XML_TAG_OPEN) {
PolicyItemType it;
if (streq(name, "allow"))
it = POLICY_ITEM_ALLOW;
else if (streq(name, "deny"))
it = POLICY_ITEM_DENY;
else {
log_warning("Unknown tag %s in <policy> %s:%u.", name, path, line);
return -EINVAL;
}
assert(!i);
i = new0(PolicyItem, 1);
if (!i)
return log_oom();
i->type = it;
state = STATE_ALLOW_DENY;
} else if (t != XML_TEXT || !in_charset(name, WHITESPACE)) {
log_error("Unexpected token (3) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY_CONTEXT:
if (t == XML_ATTRIBUTE_VALUE) {
if (streq(name, "default")) {
policy_category = POLICY_CATEGORY_DEFAULT;
state = STATE_POLICY;
} else if (streq(name, "mandatory")) {
policy_category = POLICY_CATEGORY_MANDATORY;
state = STATE_POLICY;
} else {
log_error("context= parameter %s unknown for <policy> at %s:%u.", name, path, line);
return -EINVAL;
}
} else {
log_error("Unexpected token (4) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY_CONSOLE:
if (t == XML_ATTRIBUTE_VALUE) {
if (streq(name, "true")) {
policy_category = POLICY_CATEGORY_ON_CONSOLE;
state = STATE_POLICY;
} else if (streq(name, "false")) {
policy_category = POLICY_CATEGORY_NO_CONSOLE;
state = STATE_POLICY;
} else {
log_error("at_console= parameter %s unknown for <policy> at %s:%u.", name, path, line);
return -EINVAL;
}
} else {
log_error("Unexpected token (4.1) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY_USER:
if (t == XML_ATTRIBUTE_VALUE) {
free(policy_user);
policy_user = name;
name = NULL;
policy_category = POLICY_CATEGORY_USER;
state = STATE_POLICY;
} else {
log_error("Unexpected token (5) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY_GROUP:
if (t == XML_ATTRIBUTE_VALUE) {
free(policy_group);
policy_group = name;
name = NULL;
policy_category = POLICY_CATEGORY_GROUP;
state = STATE_POLICY;
} else {
log_error("Unexpected token (6) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_POLICY_OTHER_ATTRIBUTE:
if (t == XML_ATTRIBUTE_VALUE)
state = STATE_POLICY;
else {
log_error("Unexpected token (7) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY:
assert(i);
if (t == XML_ATTRIBUTE_NAME) {
PolicyItemClass ic;
if (startswith(name, "send_"))
ic = POLICY_ITEM_SEND;
else if (startswith(name, "receive_"))
ic = POLICY_ITEM_RECV;
else if (streq(name, "own"))
ic = POLICY_ITEM_OWN;
else if (streq(name, "own_prefix"))
ic = POLICY_ITEM_OWN_PREFIX;
else if (streq(name, "user"))
ic = POLICY_ITEM_USER;
else if (streq(name, "group"))
ic = POLICY_ITEM_GROUP;
else if (STR_IN_SET(name, "eavesdrop", "log")) {
log_debug("Unsupported attribute %s= at %s:%u, ignoring.", name, path, line);
state = STATE_ALLOW_DENY_OTHER_ATTRIBUTE;
break;
} else {
log_error("Unknown attribute %s= at %s:%u, ignoring.", name, path, line);
state = STATE_ALLOW_DENY_OTHER_ATTRIBUTE;
break;
}
if (i->class != _POLICY_ITEM_CLASS_UNSET && ic != i->class) {
log_error("send_, receive_/eavesdrop fields mixed on same tag at %s:%u.", path, line);
return -EINVAL;
}
i->class = ic;
if (ic == POLICY_ITEM_SEND || ic == POLICY_ITEM_RECV) {
const char *u;
u = strchr(name, '_');
assert(u);
u++;
if (streq(u, "interface"))
state = STATE_ALLOW_DENY_INTERFACE;
else if (streq(u, "member"))
state = STATE_ALLOW_DENY_MEMBER;
else if (streq(u, "error"))
state = STATE_ALLOW_DENY_ERROR;
else if (streq(u, "path"))
state = STATE_ALLOW_DENY_PATH;
else if (streq(u, "type"))
state = STATE_ALLOW_DENY_MESSAGE_TYPE;
else if ((streq(u, "destination") && ic == POLICY_ITEM_SEND) ||
(streq(u, "sender") && ic == POLICY_ITEM_RECV))
state = STATE_ALLOW_DENY_NAME;
else {
if (streq(u, "requested_reply"))
log_debug("Unsupported attribute %s= at %s:%u, ignoring.", name, path, line);
else
log_error("Unknown attribute %s= at %s:%u, ignoring.", name, path, line);
state = STATE_ALLOW_DENY_OTHER_ATTRIBUTE;
break;
}
} else
state = STATE_ALLOW_DENY_NAME;
} else if (t == XML_TAG_CLOSE_EMPTY ||
(t == XML_TAG_CLOSE && streq(name, i->type == POLICY_ITEM_ALLOW ? "allow" : "deny"))) {
/* If the tag is fully empty so far, we consider it a recv */
if (i->class == _POLICY_ITEM_CLASS_UNSET)
i->class = POLICY_ITEM_RECV;
if (policy_category == POLICY_CATEGORY_DEFAULT)
item_append(i, &p->default_items);
else if (policy_category == POLICY_CATEGORY_MANDATORY)
item_append(i, &p->mandatory_items);
else if (policy_category == POLICY_CATEGORY_ON_CONSOLE)
item_append(i, &p->on_console_items);
else if (policy_category == POLICY_CATEGORY_NO_CONSOLE)
item_append(i, &p->no_console_items);
else if (policy_category == POLICY_CATEGORY_USER) {
const char *u = policy_user;
assert_cc(sizeof(uid_t) == sizeof(uint32_t));
r = hashmap_ensure_allocated(&p->user_items, NULL);
if (r < 0)
return log_oom();
if (!u) {
log_error("User policy without name");
return -EINVAL;
}
r = get_user_creds(&u, &i->uid, NULL, NULL, NULL);
if (r < 0) {
log_error_errno(r, "Failed to resolve user %s, ignoring policy: %m", u);
free(i);
} else {
PolicyItem *first;
first = hashmap_get(p->user_items, UINT32_TO_PTR(i->uid));
item_append(i, &first);
i->uid_valid = true;
r = hashmap_replace(p->user_items, UINT32_TO_PTR(i->uid), first);
if (r < 0) {
LIST_REMOVE(items, first, i);
return log_oom();
}
}
} else if (policy_category == POLICY_CATEGORY_GROUP) {
const char *g = policy_group;
assert_cc(sizeof(gid_t) == sizeof(uint32_t));
r = hashmap_ensure_allocated(&p->group_items, NULL);
if (r < 0)
return log_oom();
if (!g) {
log_error("Group policy without name");
return -EINVAL;
}
r = get_group_creds(&g, &i->gid);
if (r < 0) {
log_error_errno(r, "Failed to resolve group %s, ignoring policy: %m", g);
free(i);
} else {
PolicyItem *first;
first = hashmap_get(p->group_items, UINT32_TO_PTR(i->gid));
item_append(i, &first);
i->gid_valid = true;
r = hashmap_replace(p->group_items, UINT32_TO_PTR(i->gid), first);
if (r < 0) {
LIST_REMOVE(items, first, i);
return log_oom();
}
}
}
state = STATE_POLICY;
i = NULL;
} else if (t != XML_TEXT || !in_charset(name, WHITESPACE)) {
log_error("Unexpected token (8) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_INTERFACE:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->interface) {
log_error("Duplicate interface at %s:%u.", path, line);
return -EINVAL;
}
if (!streq(name, "*")) {
i->interface = name;
name = NULL;
}
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (9) at %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_MEMBER:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->member) {
log_error("Duplicate member in %s:%u.", path, line);
return -EINVAL;
}
if (!streq(name, "*")) {
i->member = name;
name = NULL;
}
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (10) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_ERROR:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->error) {
log_error("Duplicate error in %s:%u.", path, line);
return -EINVAL;
}
if (!streq(name, "*")) {
i->error = name;
name = NULL;
}
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (11) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_PATH:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->path) {
log_error("Duplicate path in %s:%u.", path, line);
return -EINVAL;
}
if (!streq(name, "*")) {
i->path = name;
name = NULL;
}
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (12) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_MESSAGE_TYPE:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->message_type != 0) {
log_error("Duplicate message type in %s:%u.", path, line);
return -EINVAL;
}
if (!streq(name, "*")) {
r = bus_message_type_from_string(name, &i->message_type);
if (r < 0) {
log_error("Invalid message type in %s:%u.", path, line);
return -EINVAL;
}
}
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (13) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_NAME:
if (t == XML_ATTRIBUTE_VALUE) {
assert(i);
if (i->name) {
log_error("Duplicate name in %s:%u.", path, line);
return -EINVAL;
}
switch (i->class) {
case POLICY_ITEM_USER:
if (!streq(name, "*")) {
const char *u = name;
r = get_user_creds(&u, &i->uid, NULL, NULL, NULL);
if (r < 0)
log_error_errno(r, "Failed to resolve user %s: %m", name);
else
i->uid_valid = true;
}
break;
case POLICY_ITEM_GROUP:
if (!streq(name, "*")) {
const char *g = name;
r = get_group_creds(&g, &i->gid);
if (r < 0)
log_error_errno(r, "Failed to resolve group %s: %m", name);
else
i->gid_valid = true;
}
break;
case POLICY_ITEM_SEND:
case POLICY_ITEM_RECV:
if (streq(name, "*"))
name = mfree(name);
break;
default:
break;
}
i->name = name;
name = NULL;
state = STATE_ALLOW_DENY;
} else {
log_error("Unexpected token (14) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_ALLOW_DENY_OTHER_ATTRIBUTE:
if (t == XML_ATTRIBUTE_VALUE)
state = STATE_ALLOW_DENY;
else {
log_error("Unexpected token (15) in %s:%u.", path, line);
return -EINVAL;
}
break;
case STATE_OTHER:
if (t == XML_TAG_OPEN)
n_other++;
else if (t == XML_TAG_CLOSE || t == XML_TAG_CLOSE_EMPTY) {
if (n_other == 0)
state = STATE_BUSCONFIG;
else
n_other--;
}
break;
}
}
}
enum {
DENY,
ALLOW,
DUNNO,
};
static const char *verdict_to_string(int v) {
switch (v) {
case DENY:
return "DENY";
case ALLOW:
return "ALLOW";
case DUNNO:
return "DUNNO";
}
return NULL;
}
struct policy_check_filter {
PolicyItemClass class;
uid_t uid;
gid_t gid;
int message_type;
const char *name;
const char *interface;
const char *path;
const char *member;
};
static int is_permissive(PolicyItem *i) {
assert(i);
return (i->type == POLICY_ITEM_ALLOW) ? ALLOW : DENY;
}
static int check_policy_item(PolicyItem *i, const struct policy_check_filter *filter) {
assert(i);
assert(filter);
switch (i->class) {
case POLICY_ITEM_SEND:
case POLICY_ITEM_RECV:
if (i->name && !streq_ptr(i->name, filter->name))
break;
if ((i->message_type != 0) && (i->message_type != filter->message_type))
break;
if (i->path && !streq_ptr(i->path, filter->path))
break;
if (i->member && !streq_ptr(i->member, filter->member))
break;
if (i->interface && !streq_ptr(i->interface, filter->interface))
break;
return is_permissive(i);
case POLICY_ITEM_OWN:
assert(filter->name);
if (streq(i->name, "*") || streq(i->name, filter->name))
return is_permissive(i);
break;
case POLICY_ITEM_OWN_PREFIX:
assert(filter->name);
if (streq(i->name, "*") || service_name_startswith(filter->name, i->name))
return is_permissive(i);
break;
case POLICY_ITEM_USER:
if (filter->uid != UID_INVALID)
if ((streq_ptr(i->name, "*") || (i->uid_valid && i->uid == filter->uid)))
return is_permissive(i);
break;
case POLICY_ITEM_GROUP:
if (filter->gid != GID_INVALID)
if ((streq_ptr(i->name, "*") || (i->gid_valid && i->gid == filter->gid)))
return is_permissive(i);
break;
case POLICY_ITEM_IGNORE:
default:
break;
}
return DUNNO;
}
static int check_policy_items(PolicyItem *items, const struct policy_check_filter *filter) {
PolicyItem *i;
int verdict = DUNNO;
assert(filter);
/* Check all policies in a set - a broader one might be followed by a more specific one,
* and the order of rules in policy definitions matters */
LIST_FOREACH(items, i, items) {
int v;
if (i->class != filter->class &&
!(i->class == POLICY_ITEM_OWN_PREFIX && filter->class == POLICY_ITEM_OWN))
continue;
v = check_policy_item(i, filter);
if (v != DUNNO)
verdict = v;
}
return verdict;
}
static int policy_check(Policy *p, const struct policy_check_filter *filter) {
PolicyItem *items;
int verdict, v;
assert(p);
assert(filter);
assert(IN_SET(filter->class, POLICY_ITEM_SEND, POLICY_ITEM_RECV, POLICY_ITEM_OWN, POLICY_ITEM_USER, POLICY_ITEM_GROUP));
/*
* The policy check is implemented by the following logic:
*
* 1. Check default items
* 2. Check group items
* 3. Check user items
* 4. Check on/no_console items
* 5. Check mandatory items
*
* Later rules override earlier rules.
*/
verdict = check_policy_items(p->default_items, filter);
if (filter->gid != GID_INVALID) {
items = hashmap_get(p->group_items, UINT32_TO_PTR(filter->gid));
if (items) {
v = check_policy_items(items, filter);
if (v != DUNNO)
verdict = v;
}
}
if (filter->uid != UID_INVALID) {
items = hashmap_get(p->user_items, UINT32_TO_PTR(filter->uid));
if (items) {
v = check_policy_items(items, filter);
if (v != DUNNO)
verdict = v;
}
}
if (filter->uid != UID_INVALID && sd_uid_get_seats(filter->uid, -1, NULL) > 0)
v = check_policy_items(p->on_console_items, filter);
else
v = check_policy_items(p->no_console_items, filter);
if (v != DUNNO)
verdict = v;
v = check_policy_items(p->mandatory_items, filter);
if (v != DUNNO)
verdict = v;
return verdict;
}
bool policy_check_own(Policy *p, uid_t uid, gid_t gid, const char *name) {
struct policy_check_filter filter = {
.class = POLICY_ITEM_OWN,
.uid = uid,
.gid = gid,
.name = name,
};
int verdict;
assert(p);
assert(name);
verdict = policy_check(p, &filter);
log_full(LOG_AUTH | (verdict != ALLOW ? LOG_WARNING : LOG_DEBUG),
"Ownership permission check for uid=" UID_FMT " gid=" GID_FMT" name=%s: %s",
uid, gid, strna(name), strna(verdict_to_string(verdict)));
return verdict == ALLOW;
}
bool policy_check_hello(Policy *p, uid_t uid, gid_t gid) {
struct policy_check_filter filter = {
.uid = uid,
.gid = gid,
};
int verdict;
assert(p);
filter.class = POLICY_ITEM_USER;
verdict = policy_check(p, &filter);
if (verdict != DENY) {
int v;
filter.class = POLICY_ITEM_GROUP;
v = policy_check(p, &filter);
if (v != DUNNO)
verdict = v;
}
log_full(LOG_AUTH | (verdict != ALLOW ? LOG_WARNING : LOG_DEBUG),
"Hello permission check for uid=" UID_FMT " gid=" GID_FMT": %s",
uid, gid, strna(verdict_to_string(verdict)));
return verdict == ALLOW;
}
bool policy_check_one_recv(Policy *p,
uid_t uid,
gid_t gid,
int message_type,
const char *name,
const char *path,
const char *interface,
const char *member) {
struct policy_check_filter filter = {
.class = POLICY_ITEM_RECV,
.uid = uid,
.gid = gid,
.message_type = message_type,
.name = name,
.interface = interface,
.path = path,
.member = member,
};
assert(p);
return policy_check(p, &filter) == ALLOW;
}
bool policy_check_recv(Policy *p,
uid_t uid,
gid_t gid,
int message_type,
Set *names,
char **namesv,
const char *path,
const char *interface,
const char *member,
bool dbus_to_kernel) {
char *n, **nv, *last = NULL;
bool allow = false;
Iterator i;
assert(p);
if (set_isempty(names) && strv_isempty(namesv)) {
allow = policy_check_one_recv(p, uid, gid, message_type, NULL, path, interface, member);
} else {
SET_FOREACH(n, names, i) {
last = n;
allow = policy_check_one_recv(p, uid, gid, message_type, n, path, interface, member);
if (allow)
break;
}
if (!allow) {
STRV_FOREACH(nv, namesv) {
last = *nv;
allow = policy_check_one_recv(p, uid, gid, message_type, *nv, path, interface, member);
if (allow)
break;
}
}
}
log_full(LOG_AUTH | (!allow ? LOG_WARNING : LOG_DEBUG),
"Receive permission check %s for uid=" UID_FMT " gid=" GID_FMT" message=%s name=%s path=%s interface=%s member=%s: %s",
dbus_to_kernel ? "dbus-1 to kernel" : "kernel to dbus-1", uid, gid, bus_message_type_to_string(message_type), strna(last),
strna(path), strna(interface), strna(member), allow ? "ALLOW" : "DENY");
return allow;
}
bool policy_check_one_send(Policy *p,
uid_t uid,
gid_t gid,
int message_type,
const char *name,
const char *path,
const char *interface,
const char *member) {
struct policy_check_filter filter = {
.class = POLICY_ITEM_SEND,
.uid = uid,
.gid = gid,
.message_type = message_type,
.name = name,
.interface = interface,
.path = path,
.member = member,
};
assert(p);
return policy_check(p, &filter) == ALLOW;
}
bool policy_check_send(Policy *p,
uid_t uid,
gid_t gid,
int message_type,
Set *names,
char **namesv,
const char *path,
const char *interface,
const char *member,
bool dbus_to_kernel,
char **out_used_name) {
char *n, **nv, *last = NULL;
bool allow = false;
Iterator i;
assert(p);
if (set_isempty(names) && strv_isempty(namesv)) {
allow = policy_check_one_send(p, uid, gid, message_type, NULL, path, interface, member);
} else {
SET_FOREACH(n, names, i) {
last = n;
allow = policy_check_one_send(p, uid, gid, message_type, n, path, interface, member);
if (allow)
break;
}
if (!allow) {
STRV_FOREACH(nv, namesv) {
last = *nv;
allow = policy_check_one_send(p, uid, gid, message_type, *nv, path, interface, member);
if (allow)
break;
}
}
}
if (out_used_name)
*out_used_name = last;
log_full(LOG_AUTH | (!allow ? LOG_WARNING : LOG_DEBUG),
"Send permission check %s for uid=" UID_FMT " gid=" GID_FMT" message=%s name=%s path=%s interface=%s member=%s: %s",
dbus_to_kernel ? "dbus-1 to kernel" : "kernel to dbus-1", uid, gid, bus_message_type_to_string(message_type), strna(last),
strna(path), strna(interface), strna(member), allow ? "ALLOW" : "DENY");
return allow;
}
int policy_load(Policy *p, char **files) {
char **i;
int r;
assert(p);
STRV_FOREACH(i, files) {
r = file_load(p, *i);
if (r == -EISDIR) {
_cleanup_strv_free_ char **l = NULL;
char **j;
r = conf_files_list(&l, ".conf", NULL, *i, NULL);
if (r < 0)
return log_error_errno(r, "Failed to get configuration file list: %m");
STRV_FOREACH(j, l)
file_load(p, *j);
}
/* We ignore all errors but EISDIR, and just proceed. */
}
return 0;
}
void policy_free(Policy *p) {
PolicyItem *i, *first;
if (!p)
return;
while ((i = p->default_items)) {
LIST_REMOVE(items, p->default_items, i);
policy_item_free(i);
}
while ((i = p->mandatory_items)) {
LIST_REMOVE(items, p->mandatory_items, i);
policy_item_free(i);
}
while ((i = p->on_console_items)) {
LIST_REMOVE(items, p->on_console_items, i);
policy_item_free(i);
}
while ((i = p->no_console_items)) {
LIST_REMOVE(items, p->no_console_items, i);
policy_item_free(i);
}
while ((first = hashmap_steal_first(p->user_items))) {
while ((i = first)) {
LIST_REMOVE(items, first, i);
policy_item_free(i);
}
}
while ((first = hashmap_steal_first(p->group_items))) {
while ((i = first)) {
LIST_REMOVE(items, first, i);
policy_item_free(i);
}
}
hashmap_free(p->user_items);
hashmap_free(p->group_items);
p->user_items = p->group_items = NULL;
}
static void dump_items(PolicyItem *items, const char *prefix) {
PolicyItem *i;
if (!items)
return;
if (!prefix)
prefix = "";
LIST_FOREACH(items, i, items) {
printf("%sType: %s\n"
"%sClass: %s\n",
prefix, policy_item_type_to_string(i->type),
prefix, policy_item_class_to_string(i->class));
if (i->interface)
printf("%sInterface: %s\n",
prefix, i->interface);
if (i->member)
printf("%sMember: %s\n",
prefix, i->member);
if (i->error)
printf("%sError: %s\n",
prefix, i->error);
if (i->path)
printf("%sPath: %s\n",
prefix, i->path);
if (i->name)
printf("%sName: %s\n",
prefix, i->name);
if (i->message_type != 0)
printf("%sMessage Type: %s\n",
prefix, bus_message_type_to_string(i->message_type));
if (i->uid_valid) {
_cleanup_free_ char *user;
user = uid_to_name(i->uid);
printf("%sUser: %s ("UID_FMT")\n",
prefix, strna(user), i->uid);
}
if (i->gid_valid) {
_cleanup_free_ char *group;
group = gid_to_name(i->gid);
printf("%sGroup: %s ("GID_FMT")\n",
prefix, strna(group), i->gid);
}
printf("%s-\n", prefix);
}
}
static void dump_hashmap_items(Hashmap *h) {
PolicyItem *i;
Iterator j;
void *k;
HASHMAP_FOREACH_KEY(i, k, h, j) {
printf("\t%s Item for %u:\n", draw_special_char(DRAW_ARROW), PTR_TO_UINT(k));
dump_items(i, "\t\t");
}
}
void policy_dump(Policy *p) {
printf("%s Default Items:\n", draw_special_char(DRAW_ARROW));
dump_items(p->default_items, "\t");
printf("%s Group Items:\n", draw_special_char(DRAW_ARROW));
dump_hashmap_items(p->group_items);
printf("%s User Items:\n", draw_special_char(DRAW_ARROW));
dump_hashmap_items(p->user_items);
printf("%s On-Console Items:\n", draw_special_char(DRAW_ARROW));
dump_items(p->on_console_items, "\t");
printf("%s No-Console Items:\n", draw_special_char(DRAW_ARROW));
dump_items(p->no_console_items, "\t");
printf("%s Mandatory Items:\n", draw_special_char(DRAW_ARROW));
dump_items(p->mandatory_items, "\t");
fflush(stdout);
}
int shared_policy_new(SharedPolicy **out) {
SharedPolicy *sp;
int r;
sp = new0(SharedPolicy, 1);
if (!sp)
return log_oom();
r = pthread_mutex_init(&sp->lock, NULL);
if (r != 0) {
r = log_error_errno(r, "Cannot initialize shared policy mutex: %m");
goto exit_free;
}
r = pthread_rwlock_init(&sp->rwlock, NULL);
if (r != 0) {
r = log_error_errno(r, "Cannot initialize shared policy rwlock: %m");
goto exit_mutex;
}
*out = sp;
sp = NULL;
return 0;
/* pthread lock destruction is not fail-safe... meh! */
exit_mutex:
pthread_mutex_destroy(&sp->lock);
exit_free:
free(sp);
return r;
}
SharedPolicy *shared_policy_free(SharedPolicy *sp) {
if (!sp)
return NULL;
policy_free(sp->policy);
pthread_rwlock_destroy(&sp->rwlock);
pthread_mutex_destroy(&sp->lock);
strv_free(sp->configuration);
free(sp);
return NULL;
}
static int shared_policy_reload_unlocked(SharedPolicy *sp, char **configuration) {
Policy old, buffer = {};
bool free_old;
int r;
assert(sp);
r = policy_load(&buffer, configuration);
if (r < 0)
return log_error_errno(r, "Failed to load policy: %m");
log_debug("Reloading configuration");
/* policy_dump(&buffer); */
pthread_rwlock_wrlock(&sp->rwlock);
memcpy(&old, &sp->buffer, sizeof(old));
memcpy(&sp->buffer, &buffer, sizeof(buffer));
free_old = !!sp->policy;
sp->policy = &sp->buffer;
pthread_rwlock_unlock(&sp->rwlock);
if (free_old)
policy_free(&old);
return 0;
}
int shared_policy_reload(SharedPolicy *sp) {
int r;
assert(sp);
pthread_mutex_lock(&sp->lock);
r = shared_policy_reload_unlocked(sp, sp->configuration);
pthread_mutex_unlock(&sp->lock);
return r;
}
int shared_policy_preload(SharedPolicy *sp, char **configuration) {
_cleanup_strv_free_ char **conf = NULL;
int r = 0;
assert(sp);
conf = strv_copy(configuration);
if (!conf)
return log_oom();
pthread_mutex_lock(&sp->lock);
if (!sp->policy) {
r = shared_policy_reload_unlocked(sp, conf);
if (r >= 0) {
sp->configuration = conf;
conf = NULL;
}
}
pthread_mutex_unlock(&sp->lock);
return r;
}
Policy *shared_policy_acquire(SharedPolicy *sp) {
assert(sp);
pthread_rwlock_rdlock(&sp->rwlock);
if (sp->policy)
return sp->policy;
pthread_rwlock_unlock(&sp->rwlock);
return NULL;
}
void shared_policy_release(SharedPolicy *sp, Policy *p) {
assert(sp);
assert(!p || sp->policy == p);
if (p)
pthread_rwlock_unlock(&sp->rwlock);
}
static const char* const policy_item_type_table[_POLICY_ITEM_TYPE_MAX] = {
[_POLICY_ITEM_TYPE_UNSET] = "unset",
[POLICY_ITEM_ALLOW] = "allow",
[POLICY_ITEM_DENY] = "deny",
};
DEFINE_STRING_TABLE_LOOKUP(policy_item_type, PolicyItemType);
static const char* const policy_item_class_table[_POLICY_ITEM_CLASS_MAX] = {
[_POLICY_ITEM_CLASS_UNSET] = "unset",
[POLICY_ITEM_SEND] = "send",
[POLICY_ITEM_RECV] = "recv",
[POLICY_ITEM_OWN] = "own",
[POLICY_ITEM_OWN_PREFIX] = "own-prefix",
[POLICY_ITEM_USER] = "user",
[POLICY_ITEM_GROUP] = "group",
[POLICY_ITEM_IGNORE] = "ignore",
};
DEFINE_STRING_TABLE_LOOKUP(policy_item_class, PolicyItemClass);