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authorLennart Poettering <lennart@poettering.net>2014-06-06 19:41:24 +0200
committerLennart Poettering <lennart@poettering.net>2014-06-06 19:41:24 +0200
commitbcf3295d2b0d87caefad2e73d221aac080d0c11e (patch)
tree0a0af0e976f18a6d56058a02240dc4d0fd58c4ce /src/bus-proxyd/bus-policy.c
parent827bf3c5dd88c51080de159e071fcbe7ada3477c (diff)
bus: add basic dbus1 policy parser
Enforcement is still missing, but at least we can parse it now.
Diffstat (limited to 'src/bus-proxyd/bus-policy.c')
-rw-r--r--src/bus-proxyd/bus-policy.c679
1 files changed, 679 insertions, 0 deletions
diff --git a/src/bus-proxyd/bus-policy.c b/src/bus-proxyd/bus-policy.c
new file mode 100644
index 0000000000..c592f501bf
--- /dev/null
+++ b/src/bus-proxyd/bus-policy.c
@@ -0,0 +1,679 @@
+/*-*- 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 "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 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;
+
+ 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 {
+ 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_USER:
+
+ if (t == XML_ATTRIBUTE_VALUE) {
+ free(policy_user);
+ policy_user = name;
+ name = NULL;
+ 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;
+ 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 {
+ 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 {
+ 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)
+ LIST_PREPEND(items, p->default_items, i);
+ else if (policy_category == POLICY_CATEGORY_MANDATORY)
+ LIST_PREPEND(items, p->default_items, i);
+ else if (policy_category == POLICY_CATEGORY_USER) {
+ PolicyItem *first;
+
+ assert_cc(sizeof(uid_t) == sizeof(uint32_t));
+
+ r = hashmap_ensure_allocated(&p->user_items, trivial_hash_func, trivial_compare_func);
+ if (r < 0)
+ return log_oom();
+
+ first = hashmap_get(p->user_items, UINT32_TO_PTR(i->uid));
+ LIST_PREPEND(items, first, i);
+
+ 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) {
+ PolicyItem *first;
+
+ assert_cc(sizeof(gid_t) == sizeof(uint32_t));
+
+ r = hashmap_ensure_allocated(&p->group_items, trivial_hash_func, trivial_compare_func);
+ if (r < 0)
+ return log_oom();
+
+ first = hashmap_get(p->group_items, UINT32_TO_PTR(i->gid));
+ LIST_PREPEND(items, first, i);
+
+ 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;
+ }
+
+ 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) {
+ _cleanup_strv_free_ char **l = NULL;
+ char **i;
+ int r;
+
+ assert(p);
+
+ file_load(p, "/etc/dbus-1/system.conf");
+ file_load(p, "/etc/dbus-1/system-local.conf");
+
+ r = conf_files_list(&l, ".conf", NULL, "/etc/dbus-1/system.d/", NULL);
+ if (r < 0) {
+ log_error("Failed to get configuration file list: %s", strerror(-r));
+ return r;
+ }
+
+ STRV_FOREACH(i, l)
+ file_load(p, *i);
+
+ 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);
+ }
+
+ policy_item_free(i);
+ }
+
+ while ((first = hashmap_steal_first(p->group_items))) {
+
+ while ((i = first)) {
+ LIST_REMOVE(items, first, i);
+ policy_item_free(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 *i) {
+
+ if (!i)
+ return;
+
+ printf("Type: %s\n"
+ "Class: %s\n",
+ policy_item_type_to_string(i->type),
+ policy_item_class_to_string(i->class));
+
+ if (i->interface)
+ printf("Interface: %s\n",
+ i->interface);
+
+ if (i->member)
+ printf("Member: %s\n",
+ i->member);
+
+ if (i->error)
+ printf("Error: %s\n",
+ i->error);
+
+ if (i->path)
+ printf("Path: %s\n",
+ i->path);
+
+ if (i->name)
+ printf("Name: %s\n",
+ i->name);
+
+ if (i->message_type != 0)
+ printf("Message Type: %s\n",
+ bus_message_type_to_string(i->message_type));
+
+ if (i->uid_valid) {
+ _cleanup_free_ char *user;
+
+ user = uid_to_name(i->uid);
+
+ printf("User: %s\n",
+ strna(user));
+ }
+
+ if (i->gid_valid) {
+ _cleanup_free_ char *group;
+
+ group = gid_to_name(i->gid);
+
+ printf("Group: %s\n",
+ strna(group));
+ }
+
+ if (i->items_next) {
+ printf("--\n");
+ dump_items(i->items_next);
+ }
+}
+
+static void dump_hashmap_items(Hashmap *h) {
+ PolicyItem *i;
+ Iterator j;
+ char *k;
+
+ HASHMAP_FOREACH_KEY(i, k, h, j) {
+ printf("Item for %s", k);
+ dump_items(i);
+ }
+}
+
+void policy_dump(Policy *p) {
+
+ printf("→ Default Items:\n");
+ dump_items(p->default_items);
+
+ printf("→ Mandatory Items:\n");
+ dump_items(p->mandatory_items);
+
+ printf("→ Group Items:\n");
+ dump_hashmap_items(p->group_items);
+
+ printf("→ User Items:\n");
+ dump_hashmap_items(p->user_items);
+ exit(0);
+}
+
+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",
+};
+DEFINE_STRING_TABLE_LOOKUP(policy_item_class, PolicyItemClass);