/*-*- 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 .
***/
#include "xml.h"
#include "fileio.h"
#include "strv.h"
#include "conf-files.h"
#include "bus-internal.h"
#include "bus-policy.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_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_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;
log_error("Failed to load %s: %s", path, strerror(-r));
return r;
}
q = c;
for (;;) {
_cleanup_free_ char *name = NULL;
int t;
t = xml_tokenize(&q, &name, &xml_state, &line);
if (t < 0) {
log_error("XML parse failure in %s: %s", path, strerror(-t));
return t;
}
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, "user"))
state = STATE_POLICY_USER;
else if (streq(name, "group"))
state = STATE_POLICY_GROUP;
else {
if (streq(name, "at_console"))
log_debug("Attribute %s of tag unsupported at %s:%u, ignoring.", name, path, line);
else
log_warning("Attribute %s of 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 %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 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_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 (streq(name, "eavesdrop")) {
log_debug("Unsupported attribute %s= at %s:%u, ignoring.", name, path, line);
i->class = POLICY_ITEM_IGNORE;
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_ and receive_ 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 (i->class == _POLICY_ITEM_CLASS_UNSET) {
log_error("Policy not set at %s:%u.", path, line);
return -EINVAL;
}
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_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("Failed to resolve user %s, ignoring policy: %s", u, strerror(-r));
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("Failed to resolve group %s, ignoring policy: %s", g, strerror(-r));
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;
}
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;
}
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;
}
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;
}
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;
}
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("Failed to resolve user %s: %s", name, strerror(-r));
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("Failed to resolve group %s: %s", name, strerror(-r));
else
i->gid_valid = true;
}
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;
}
}
}
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) {
log_error("Failed to get configuration file list: %s", strerror(-r));
return r;
}
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 ((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\n",
prefix, strna(user));
}
if (i->gid_valid) {
_cleanup_free_ char *group;
group = gid_to_name(i->gid);
printf("%sGroup: %s\n",
prefix, strna(group));
}
}
}
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 Mandatory Items:\n", draw_special_char(DRAW_ARROW));
dump_items(p->mandatory_items, "\t");
}
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);