mirror of
https://github.com/systemd/systemd-stable.git
synced 2024-12-22 13:33:56 +03:00
bus-policy: split API for bus-proxyd
Instead of operating on an sd_bus_message object, expose an API that has 4 functions: policy_check_own() policy_check_hello() policy_check_recv() policy_check_send() This also allows dropping extra code to parse message contents - the bus proxy already has dedicated code paths for that, and we can hook into those later. Tests amended accordingly.
This commit is contained in:
parent
04c553e322
commit
078ef7b85a
@ -592,93 +592,73 @@ static int file_load(Policy *p, const char *path) {
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}
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}
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static bool is_matching_name_request(sd_bus_message *m, const char *name, bool prefix) {
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char *n = NULL;
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int r;
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if (!sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "RequestName"))
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return false;
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r = sd_bus_message_read(m, "s", &n);
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if (r < 0)
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return false;
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r = sd_bus_message_rewind(m, true);
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if (r < 0)
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return false;
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if (prefix)
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return startswith(name, n);
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else
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return streq_ptr(name, n);
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}
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static bool is_matching_call(PolicyItem *i, sd_bus_message *m, const char *name) {
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if (i->message_type && (i->message_type != m->header->type))
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return false;
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if (i->path && (!m->path || !streq(i->path, m->path)))
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return false;
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if (i->member && (!m->member || !streq(i->member, m->member)))
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return false;
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if (i->interface && (!m->interface || !streq(i->interface, m->interface)))
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return false;
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if (i->name && (!name || !streq(i->name, name)))
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return false;
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return true;
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}
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enum {
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ALLOW,
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DUNNO,
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DENY,
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};
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struct policy_check_filter {
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int class;
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const struct ucred *ucred;
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int message_type;
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const char *interface;
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const char *path;
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const char *member;
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char **names_strv;
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Hashmap *names_hash;
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};
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static int is_permissive(PolicyItem *i) {
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return (i->type == POLICY_ITEM_ALLOW) ? ALLOW : DENY;
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}
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static int check_policy_item(PolicyItem *i, sd_bus_message *m, const struct ucred *ucred) {
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static int check_policy_item(PolicyItem *i, const struct policy_check_filter *filter) {
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switch (i->class) {
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case POLICY_ITEM_SEND:
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if ((m->bus->is_kernel && is_matching_call(i, m, m->destination)) ||
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(!m->bus->is_kernel && is_matching_call(i, m, m->sender)))
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return is_permissive(i);
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break;
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case POLICY_ITEM_RECV:
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if ((m->bus->is_kernel && is_matching_call(i, m, m->sender)) ||
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(!m->bus->is_kernel && is_matching_call(i, m, m->destination)))
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return is_permissive(i);
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break;
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if (i->name) {
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if (filter->names_hash && !hashmap_contains(filter->names_hash, i->name))
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break;
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if (filter->names_strv && !strv_contains(filter->names_strv, i->name))
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break;
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}
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if (i->message_type && (i->message_type != filter->message_type))
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break;
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if (i->path && !streq_ptr(i->path, filter->path))
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break;
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if (i->member && !streq_ptr(i->member, filter->member))
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break;
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if (i->interface && !streq_ptr(i->interface, filter->interface))
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break;
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return is_permissive(i);
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case POLICY_ITEM_OWN:
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if (is_matching_name_request(m, i->name, false))
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if (streq(i->name, filter->member))
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return is_permissive(i);
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break;
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case POLICY_ITEM_OWN_PREFIX:
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if (is_matching_name_request(m, i->name, true))
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if (startswith(i->name, filter->member))
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return is_permissive(i);
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break;
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case POLICY_ITEM_USER:
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if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "Hello") &&
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(streq_ptr(i->name, "*") || (i->uid_valid && i->uid == ucred->uid)))
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if ((streq_ptr(i->name, "*") || (i->uid_valid && i->uid == filter->ucred->uid)))
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return is_permissive(i);
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break;
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case POLICY_ITEM_GROUP:
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if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "Hello") &&
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(streq_ptr(i->name, "*") || (i->gid_valid && i->gid == ucred->gid)))
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if ((streq_ptr(i->name, "*") || (i->gid_valid && i->gid == filter->ucred->gid)))
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return is_permissive(i);
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break;
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@ -690,7 +670,7 @@ static int check_policy_item(PolicyItem *i, sd_bus_message *m, const struct ucre
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return DUNNO;
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}
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static int check_policy_items(PolicyItem *items, sd_bus_message *m, const struct ucred *ucred) {
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static int check_policy_items(PolicyItem *items, const struct policy_check_filter *filter) {
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PolicyItem *i;
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int r, ret = DUNNO;
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@ -698,7 +678,10 @@ static int check_policy_items(PolicyItem *items, sd_bus_message *m, const struct
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/* Check all policies in a set - a broader one might be followed by a more specific one,
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* and the order of rules in policy definitions matters */
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LIST_FOREACH(items, i, items) {
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r = check_policy_item(i, m, ucred);
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if (i->class != filter->class)
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continue;
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r = check_policy_item(i, filter);
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if (r != DUNNO)
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ret = r;
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}
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@ -706,7 +689,7 @@ static int check_policy_items(PolicyItem *items, sd_bus_message *m, const struct
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return ret;
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}
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bool policy_check(Policy *p, sd_bus_message *m, const struct ucred *ucred) {
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static int policy_check(Policy *p, const struct policy_check_filter *filter) {
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PolicyItem *items;
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int r;
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@ -720,31 +703,100 @@ bool policy_check(Policy *p, sd_bus_message *m, const struct ucred *ucred) {
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* 4. If the message isn't caught be the defaults either, reject it.
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*/
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r = check_policy_items(p->mandatory_items, m, ucred);
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r = check_policy_items(p->mandatory_items, filter);
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if (r != DUNNO)
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return r == ALLOW;
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return r;
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if (ucred->pid > 0) {
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items = hashmap_get(p->user_items, UINT32_TO_PTR(ucred->uid));
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if (filter->ucred) {
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items = hashmap_get(p->user_items, UINT32_TO_PTR(filter->ucred->uid));
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if (items) {
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r = check_policy_items(items, m, ucred);
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r = check_policy_items(items, filter);
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if (r != DUNNO)
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return r == ALLOW;
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return r;
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}
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items = hashmap_get(p->group_items, UINT32_TO_PTR(ucred->gid));
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items = hashmap_get(p->group_items, UINT32_TO_PTR(filter->ucred->gid));
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if (items) {
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r = check_policy_items(items, m, ucred);
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r = check_policy_items(items, filter);
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if (r != DUNNO)
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return r == ALLOW;
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return r;
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}
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}
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r = check_policy_items(p->default_items, m, ucred);
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if (r != DUNNO)
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return r == ALLOW;
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return check_policy_items(p->default_items, filter);
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}
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return false;
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bool policy_check_own(Policy *p, const struct ucred *ucred, const char *name) {
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struct policy_check_filter filter = {
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.class = POLICY_ITEM_OWN,
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.ucred = ucred,
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.member = name,
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};
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return policy_check(p, &filter) == ALLOW;
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}
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bool policy_check_hello(Policy *p, const struct ucred *ucred) {
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struct policy_check_filter filter = {
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.class = POLICY_ITEM_USER,
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.ucred = ucred,
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};
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int user, group;
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user = policy_check(p, &filter);
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if (user == DENY)
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return false;
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filter.class = POLICY_ITEM_GROUP;
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group = policy_check(p, &filter);
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if (user == DUNNO && group == DUNNO)
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return false;
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return !(user == DENY || group == DENY);
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}
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bool policy_check_recv(Policy *p,
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const struct ucred *ucred,
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Hashmap *names,
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int message_type,
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const char *path,
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const char *interface,
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const char *member) {
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struct policy_check_filter filter = {
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.class = POLICY_ITEM_RECV,
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.ucred = ucred,
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.names_hash = names,
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.message_type = message_type,
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.interface = interface,
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.path = path,
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.member = member,
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};
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return policy_check(p, &filter) == ALLOW;
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}
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bool policy_check_send(Policy *p,
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const struct ucred *ucred,
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char **names,
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int message_type,
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const char *path,
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const char *interface,
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const char *member) {
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struct policy_check_filter filter = {
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.class = POLICY_ITEM_SEND,
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.ucred = ucred,
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.names_strv = names,
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.message_type = message_type,
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.interface = interface,
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.path = path,
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.member = member,
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};
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return policy_check(p, &filter) == ALLOW;
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}
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int policy_load(Policy *p, char **files) {
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@ -76,7 +76,22 @@ typedef struct Policy {
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int policy_load(Policy *p, char **files);
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void policy_free(Policy *p);
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bool policy_check(Policy *p, sd_bus_message *m, const struct ucred *c);
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bool policy_check_own(Policy *p, const struct ucred *ucred, const char *name);
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bool policy_check_hello(Policy *p, const struct ucred *ucred);
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bool policy_check_recv(Policy *p,
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const struct ucred *ucred,
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Hashmap *names,
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int message_type,
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const char *path,
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const char *interface,
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const char *member);
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bool policy_check_send(Policy *p,
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const struct ucred *ucred,
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char **names,
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int message_type,
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const char *path,
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const char *interface,
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const char *member);
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void policy_dump(Policy *p);
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@ -44,122 +44,84 @@
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#include <bus-proxyd/bus-policy.h>
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static int make_name_request(sd_bus *bus,
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const char *name,
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sd_bus_message **ret) {
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int r;
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sd_bus_message *m = NULL;
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r = sd_bus_message_new_method_call(bus, &m, "org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", "RequestName");
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if (r < 0)
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return r;
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r = sd_bus_message_append_basic(m, 's', name);
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if (r < 0)
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return r;
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m->sealed = 1;
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sd_bus_message_rewind(m, true);
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*ret = m;
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return 0;
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}
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int main(int argc, char *argv[]) {
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Policy p = {};
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sd_bus_message *m;
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struct ucred ucred = {};
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_cleanup_bus_close_unref_ sd_bus *bus = NULL;;
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assert_se(sd_bus_default_system(&bus) >= 0);
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/* Fake pid for policy checks */
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ucred.pid = 1;
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char **names_strv;
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Hashmap *names_hash;
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/* Ownership tests */
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assert_se(policy_load(&p, STRV_MAKE("test/bus-policy/ownerships.conf")) == 0);
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assert_se(make_name_request(bus, "org.test.test1", &m) == 0);
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ucred.uid = 0;
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(policy_check_own(&p, &ucred, "org.test.test1") == true);
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ucred.uid = 1;
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(sd_bus_message_unref(m) == 0);
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assert_se(policy_check_own(&p, &ucred, "org.test.test1") == true);
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assert_se(make_name_request(bus, "org.test.test2", &m) == 0);
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ucred.uid = 0;
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(policy_check_own(&p, &ucred, "org.test.test2") == true);
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ucred.uid = 1;
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(sd_bus_message_unref(m) == 0);
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assert_se(policy_check_own(&p, &ucred, "org.test.test2") == false);
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assert_se(make_name_request(bus, "org.test.test3", &m) == 0);
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ucred.uid = 0;
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(policy_check_own(&p, &ucred, "org.test.test3") == false);
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ucred.uid = 1;
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(sd_bus_message_unref(m) == 0);
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assert_se(policy_check_own(&p, &ucred, "org.test.test3") == false);
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assert_se(make_name_request(bus, "org.test.test4", &m) == 0);
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ucred.uid = 0;
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(policy_check_own(&p, &ucred, "org.test.test4") == false);
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ucred.uid = 1;
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(sd_bus_message_unref(m) == 0);
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assert_se(policy_check_own(&p, &ucred, "org.test.test4") == true);
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policy_free(&p);
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/* Signal test */
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/* Signaltest */
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assert_se(policy_load(&p, STRV_MAKE("test/bus-policy/signals.conf")) == 0);
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names_strv = STRV_MAKE("bli.bla.blubb");
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assert_se(sd_bus_message_new_signal(bus, &m, "/an/object/path", "bli.bla.blubb", "Name") == 0);
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ucred.uid = 0;
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_SIGNAL, NULL, "/an/object/path", NULL) == true);
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ucred.uid = 1;
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(sd_bus_message_unref(m) == 0);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_SIGNAL, NULL, "/an/object/path", NULL) == false);
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policy_free(&p);
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/* Method calls */
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assert_se(policy_load(&p, STRV_MAKE("test/bus-policy/methods.conf")) == 0);
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names_strv = STRV_MAKE("org.test.test1");
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policy_dump(&p);
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ucred.uid = 0;
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assert_se(sd_bus_message_new_method_call(bus, &m, "org.foo.bar", "/an/object/path", "bli.bla.blubb", "Member") == 0);
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(sd_bus_message_new_method_call(bus, &m, "org.test.test1", "/an/object/path", "bli.bla.blubb", "Member") == 0);
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assert_se(policy_check(&p, m, &ucred) == false);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_METHOD_CALL, "/an/object/path", "bli.bla.blubb", "Member") == false);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_METHOD_CALL, "/an/object/path", "bli.bla.blubb", "Member") == false);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_METHOD_CALL, "/an/object/path", "org.test.int1", "Member") == true);
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assert_se(policy_check_send(&p, &ucred, names_strv, SD_BUS_MESSAGE_METHOD_CALL, "/an/object/path", "org.test.int2", "Member") == true);
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bus->is_kernel = 1;
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assert_se(sd_bus_message_new_method_call(bus, &m, "org.test.test1", "/an/object/path", "org.test.int1", "Member") == 0);
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assert_se(policy_check(&p, m, &ucred) == true);
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assert_se(sd_bus_message_new_method_call(bus, &m, "org.test.test1", "/an/object/path", "org.test.int2", "Member") == 0);
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assert_se(policy_check(&p, m, &ucred) == true);
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names_hash = hashmap_new(&string_hash_ops);
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assert(names_hash != NULL);
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assert_se(hashmap_put(names_hash, "org.test.test3", NULL) >= 0);
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assert_se(policy_check_recv(&p, &ucred, names_hash, SD_BUS_MESSAGE_METHOD_CALL, "/an/object/path", "org.test.int3", "Member111") == true);
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policy_free(&p);
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/* User and groups */
|
||||
assert_se(policy_load(&p, STRV_MAKE("test/bus-policy/hello.conf")) == 0);
|
||||
assert_se(sd_bus_message_new_method_call(bus, &m, "org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", "Hello") == 0);
|
||||
policy_dump(&p);
|
||||
|
||||
ucred.uid = 0;
|
||||
assert_se(policy_check(&p, m, &ucred) == true);
|
||||
assert_se(policy_check_hello(&p, &ucred) == true);
|
||||
|
||||
ucred.uid = 1;
|
||||
assert_se(policy_check(&p, m, &ucred) == false);
|
||||
assert_se(policy_check_hello(&p, &ucred) == false);
|
||||
|
||||
ucred.uid = 0;
|
||||
ucred.gid = 1;
|
||||
assert_se(policy_check(&p, m, &ucred) == false);
|
||||
assert_se(policy_check_hello(&p, &ucred) == false);
|
||||
|
||||
policy_free(&p);
|
||||
|
||||
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
@ -10,6 +10,8 @@
|
||||
<deny send_destination="org.test.test1"/>
|
||||
<allow send_destination="org.test.test1" send_interface="org.test.int1"/>
|
||||
<allow send_destination="org.test.test1" send_interface="org.test.int2"/>
|
||||
|
||||
<allow receive_sender="org.test.test3" receive_interface="org.test.int3" receiver_member="Member111"/>
|
||||
</policy>
|
||||
|
||||
</busconfig>
|
||||
|
Loading…
Reference in New Issue
Block a user