Initial import

1 files changed, 632 insertions, 0 deletions

diff --git a/tools/testing/selftests/kdbus/test-policy-ns.c b/tools/testing/selftests/kdbus/test-policy-ns.c
new file mode 100644
index 000000000..3437012f9
--- /dev/null
+++ b/tools/testing/selftests/kdbus/test-policy-ns.c
@@ -0,0 +1,632 @@
+/*
+ * Test metadata and policies in new namespaces. Even if our tests
+ * can run in a namespaced setup, this test is necessary so we can
+ * inspect policies on the same kdbusfs but between multiple
+ * namespaces.
+ *
+ * Copyright (C) 2014-2015 Djalal Harouni
+ *
+ * kdbus 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.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <sys/prctl.h>
+#include <sys/eventfd.h>
+#include <sys/syscall.h>
+#include <sys/capability.h>
+#include <linux/sched.h>
+
+#include "kdbus-test.h"
+#include "kdbus-util.h"
+#include "kdbus-enum.h"
+
+#define MAX_CONN	64
+#define POLICY_NAME	"foo.test.policy-test"
+
+#define KDBUS_CONN_MAX_MSGS_PER_USER            16
+
+/**
+ * Note: this test can be used to inspect policy_db->talk_access_hash
+ *
+ * The purpose of these tests:
+ * 1) Check KDBUS_POLICY_TALK
+ * 2) Check the cache state: kdbus_policy_db->talk_access_hash
+ * Should be extended
+ */
+
+/**
+ * Check a list of connections against conn_db[0]
+ * conn_db[0] will own the name "foo.test.policy-test" and the
+ * policy holder connection for this name will update the policy
+ * entries, so different use cases can be tested.
+ */
+static struct kdbus_conn **conn_db;
+
+static void *kdbus_recv_echo(void *ptr)
+{
+	int ret;
+	struct kdbus_conn *conn = ptr;
+
+	ret = kdbus_msg_recv_poll(conn, 200, NULL, NULL);
+
+	return (void *)(long)ret;
+}
+
+/* Trigger kdbus_policy_set() */
+static int kdbus_set_policy_talk(struct kdbus_conn *conn,
+				 const char *name,
+				 uid_t id, unsigned int type)
+{
+	int ret;
+	struct kdbus_policy_access access = {
+		.type = type,
+		.id = id,
+		.access = KDBUS_POLICY_TALK,
+	};
+
+	ret = kdbus_conn_update_policy(conn, name, &access, 1);
+	ASSERT_RETURN(ret == 0);
+
+	return TEST_OK;
+}
+
+/* return TEST_OK or TEST_ERR on failure */
+static int kdbus_register_same_activator(char *bus, const char *name,
+					 struct kdbus_conn **c)
+{
+	int ret;
+	struct kdbus_conn *activator;
+
+	activator = kdbus_hello_activator(bus, name, NULL, 0);
+	if (activator) {
+		*c = activator;
+		fprintf(stderr, "--- error was able to register name twice '%s'.\n",
+			name);
+		return TEST_ERR;
+	}
+
+	ret = -errno;
+	/* -EEXIST means test succeeded */
+	if (ret == -EEXIST)
+		return TEST_OK;
+
+	return TEST_ERR;
+}
+
+/* return TEST_OK or TEST_ERR on failure */
+static int kdbus_register_policy_holder(char *bus, const char *name,
+					struct kdbus_conn **conn)
+{
+	struct kdbus_conn *c;
+	struct kdbus_policy_access access[2];
+
+	access[0].type = KDBUS_POLICY_ACCESS_USER;
+	access[0].access = KDBUS_POLICY_OWN;
+	access[0].id = geteuid();
+
+	access[1].type = KDBUS_POLICY_ACCESS_WORLD;
+	access[1].access = KDBUS_POLICY_TALK;
+	access[1].id = geteuid();
+
+	c = kdbus_hello_registrar(bus, name, access, 2,
+				  KDBUS_HELLO_POLICY_HOLDER);
+	ASSERT_RETURN(c);
+
+	*conn = c;
+
+	return TEST_OK;
+}
+
+/**
+ * Create new threads for receiving from multiple senders,
+ * The 'conn_db' will be populated by newly created connections.
+ * Caller should free all allocated connections.
+ *
+ * return 0 on success, negative errno on failure.
+ */
+static int kdbus_recv_in_threads(const char *bus, const char *name,
+				 struct kdbus_conn **conn_db)
+{
+	int ret;
+	bool pool_full = false;
+	unsigned int sent_packets = 0;
+	unsigned int lost_packets = 0;
+	unsigned int i, tid;
+	unsigned long dst_id;
+	unsigned long cookie = 1;
+	unsigned int thread_nr = MAX_CONN - 1;
+	pthread_t thread_id[MAX_CONN - 1] = {'\0'};
+
+	dst_id = name ? KDBUS_DST_ID_NAME : conn_db[0]->id;
+
+	for (tid = 0, i = 1; tid < thread_nr; tid++, i++) {
+		ret = pthread_create(&thread_id[tid], NULL,
+				     kdbus_recv_echo, (void *)conn_db[0]);
+		if (ret < 0) {
+			ret = -errno;
+			kdbus_printf("error pthread_create: %d (%m)\n",
+				      ret);
+			break;
+		}
+
+		/* just free before re-using */
+		kdbus_conn_free(conn_db[i]);
+		conn_db[i] = NULL;
+
+		/* We need to create connections here */
+		conn_db[i] = kdbus_hello(bus, 0, NULL, 0);
+		if (!conn_db[i]) {
+			ret = -errno;
+			break;
+		}
+
+		ret = kdbus_add_match_empty(conn_db[i]);
+		if (ret < 0)
+			break;
+
+		ret = kdbus_msg_send(conn_db[i], name, cookie++,
+				     0, 0, 0, dst_id);
+		if (ret < 0) {
+			/*
+			 * Receivers are not reading their messages,
+			 * not scheduled ?!
+			 *
+			 * So set the pool full here, perhaps the
+			 * connection pool or queue was full, later
+			 * recheck receivers errors
+			 */
+			if (ret == -ENOBUFS || ret == -EXFULL)
+				pool_full = true;
+			break;
+		}
+
+		sent_packets++;
+	}
+
+	for (tid = 0; tid < thread_nr; tid++) {
+		int thread_ret = 0;
+
+		if (thread_id[tid]) {
+			pthread_join(thread_id[tid], (void *)&thread_ret);
+			if (thread_ret < 0) {
+				/* Update only if send did not fail */
+				if (ret == 0)
+					ret = thread_ret;
+
+				lost_packets++;
+			}
+		}
+	}
+
+	/*
+	 * When sending if we did fail with -ENOBUFS or -EXFULL
+	 * then we should have set lost_packet and we should at
+	 * least have sent_packets set to KDBUS_CONN_MAX_MSGS_PER_USER
+	 */
+	if (pool_full) {
+		ASSERT_RETURN(lost_packets > 0);
+
+		/*
+		 * We should at least send KDBUS_CONN_MAX_MSGS_PER_USER
+		 *
+		 * For every send operation we create a thread to
+		 * recv the packet, so we keep the queue clean
+		 */
+		ASSERT_RETURN(sent_packets >= KDBUS_CONN_MAX_MSGS_PER_USER);
+
+		/*
+		 * Set ret to zero since we only failed due to
+		 * the receiving threads that have not been
+		 * scheduled
+		 */
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/* Return: TEST_OK or TEST_ERR on failure */
+static int kdbus_normal_test(const char *bus, const char *name,
+			     struct kdbus_conn **conn_db)
+{
+	int ret;
+
+	ret = kdbus_recv_in_threads(bus, name, conn_db);
+	ASSERT_RETURN(ret >= 0);
+
+	return TEST_OK;
+}
+
+static int kdbus_fork_test_by_id(const char *bus,
+				 struct kdbus_conn **conn_db,
+				 int parent_status, int child_status)
+{
+	int ret;
+	pid_t pid;
+	uint64_t cookie = 0x9876ecba;
+	struct kdbus_msg *msg = NULL;
+	uint64_t offset = 0;
+	int status = 0;
+
+	/*
+	 * If the child_status is not EXIT_SUCCESS, then we expect
+	 * that sending from the child will fail, thus receiving
+	 * from parent must error with -ETIMEDOUT, and vice versa.
+	 */
+	bool parent_timedout = !!child_status;
+	bool child_timedout = !!parent_status;
+
+	pid = fork();
+	ASSERT_RETURN_VAL(pid >= 0, pid);
+
+	if (pid == 0) {
+		struct kdbus_conn *conn_src;
+
+		ret = prctl(PR_SET_PDEATHSIG, SIGKILL);
+		ASSERT_EXIT(ret == 0);
+
+		ret = drop_privileges(65534, 65534);
+		ASSERT_EXIT(ret == 0);
+
+		conn_src = kdbus_hello(bus, 0, NULL, 0);
+		ASSERT_EXIT(conn_src);
+
+		ret = kdbus_add_match_empty(conn_src);
+		ASSERT_EXIT(ret == 0);
+
+		/*
+		 * child_status is always checked against send
+		 * operations, in case it fails always return
+		 * EXIT_FAILURE.
+		 */
+		ret = kdbus_msg_send(conn_src, NULL, cookie,
+				     0, 0, 0, conn_db[0]->id);
+		ASSERT_EXIT(ret == child_status);
+
+		ret = kdbus_msg_recv_poll(conn_src, 100, NULL, NULL);
+
+		kdbus_conn_free(conn_src);
+
+		/*
+		 * Child kdbus_msg_recv_poll() should timeout since
+		 * the parent_status was set to a non EXIT_SUCCESS
+		 * value.
+		 */
+		if (child_timedout)
+			_exit(ret == -ETIMEDOUT ? EXIT_SUCCESS : EXIT_FAILURE);
+
+		_exit(ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+	}
+
+	ret = kdbus_msg_recv_poll(conn_db[0], 100, &msg, &offset);
+	/*
+	 * If parent_timedout is set then this should fail with
+	 * -ETIMEDOUT since the child_status was set to a non
+	 * EXIT_SUCCESS value. Otherwise, assume
+	 * that kdbus_msg_recv_poll() has succeeded.
+	 */
+	if (parent_timedout) {
+		ASSERT_RETURN_VAL(ret == -ETIMEDOUT, TEST_ERR);
+
+		/* timedout no need to continue, we don't have the
+		 * child connection ID, so just terminate. */
+		goto out;
+	} else {
+		ASSERT_RETURN_VAL(ret == 0, ret);
+	}
+
+	ret = kdbus_msg_send(conn_db[0], NULL, ++cookie,
+			     0, 0, 0, msg->src_id);
+	/*
+	 * parent_status is checked against send operations,
+	 * on failures always return TEST_ERR.
+	 */
+	ASSERT_RETURN_VAL(ret == parent_status, TEST_ERR);
+
+	kdbus_msg_free(msg);
+	kdbus_free(conn_db[0], offset);
+
+out:
+	ret = waitpid(pid, &status, 0);
+	ASSERT_RETURN_VAL(ret >= 0, ret);
+
+	return (status == EXIT_SUCCESS) ? TEST_OK : TEST_ERR;
+}
+
+/*
+ * Return: TEST_OK, TEST_ERR or TEST_SKIP
+ * we return TEST_OK only if the children return with the expected
+ * 'expected_status' that is specified as an argument.
+ */
+static int kdbus_fork_test(const char *bus, const char *name,
+			   struct kdbus_conn **conn_db, int expected_status)
+{
+	pid_t pid;
+	int ret = 0;
+	int status = 0;
+
+	pid = fork();
+	ASSERT_RETURN_VAL(pid >= 0, pid);
+
+	if (pid == 0) {
+		ret = prctl(PR_SET_PDEATHSIG, SIGKILL);
+		ASSERT_EXIT(ret == 0);
+
+		ret = drop_privileges(65534, 65534);
+		ASSERT_EXIT(ret == 0);
+
+		ret = kdbus_recv_in_threads(bus, name, conn_db);
+		_exit(ret == expected_status ? EXIT_SUCCESS : EXIT_FAILURE);
+	}
+
+	ret = waitpid(pid, &status, 0);
+	ASSERT_RETURN(ret >= 0);
+
+	return (status == EXIT_SUCCESS) ? TEST_OK : TEST_ERR;
+}
+
+/* Return EXIT_SUCCESS, EXIT_FAILURE or negative errno */
+static int __kdbus_clone_userns_test(const char *bus,
+				     const char *name,
+				     struct kdbus_conn **conn_db,
+				     int expected_status)
+{
+	int efd;
+	pid_t pid;
+	int ret = 0;
+	unsigned int uid = 65534;
+	int status;
+
+	ret = drop_privileges(uid, uid);
+	ASSERT_RETURN_VAL(ret == 0, ret);
+
+	/*
+	 * Since we just dropped privileges, the dumpable flag was just
+	 * cleared which makes the /proc/$clone_child/uid_map to be
+	 * owned by root, hence any userns uid mapping will fail with
+	 * -EPERM since the mapping will be done by uid 65534.
+	 *
+	 * To avoid this set the dumpable flag again which makes procfs
+	 * update the /proc/$clone_child/ inodes owner to 65534.
+	 *
+	 * Using this we will be able write to /proc/$clone_child/uid_map
+	 * as uid 65534 and map the uid 65534 to 0 inside the user
+	 * namespace.
+	 */
+	ret = prctl(PR_SET_DUMPABLE, SUID_DUMP_USER);
+	ASSERT_RETURN_VAL(ret == 0, ret);
+
+	/* sync parent/child */
+	efd = eventfd(0, EFD_CLOEXEC);
+	ASSERT_RETURN_VAL(efd >= 0, efd);
+
+	pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWUSER, NULL);
+	if (pid < 0) {
+		ret = -errno;
+		kdbus_printf("error clone: %d (%m)\n", ret);
+		/*
+		 * Normal user not allowed to create userns,
+		 * so nothing to worry about ?
+		 */
+		if (ret == -EPERM) {
+			kdbus_printf("-- CLONE_NEWUSER TEST Failed for uid: %u\n"
+				"-- Make sure that your kernel do not allow "
+				"CLONE_NEWUSER for unprivileged users\n"
+				"-- Upstream Commit: "
+				"https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=5eaf563e\n",
+				uid);
+			ret = 0;
+		}
+
+		return ret;
+	}
+
+	if (pid == 0) {
+		struct kdbus_conn *conn_src;
+		eventfd_t event_status = 0;
+
+		ret = prctl(PR_SET_PDEATHSIG, SIGKILL);
+		ASSERT_EXIT(ret == 0);
+
+		ret = eventfd_read(efd, &event_status);
+		ASSERT_EXIT(ret >= 0 && event_status == 1);
+
+		/* ping connection from the new user namespace */
+		conn_src = kdbus_hello(bus, 0, NULL, 0);
+		ASSERT_EXIT(conn_src);
+
+		ret = kdbus_add_match_empty(conn_src);
+		ASSERT_EXIT(ret == 0);
+
+		ret = kdbus_msg_send(conn_src, name, 0xabcd1234,
+				     0, 0, 0, KDBUS_DST_ID_NAME);
+		kdbus_conn_free(conn_src);
+
+		_exit(ret == expected_status ? EXIT_SUCCESS : EXIT_FAILURE);
+	}
+
+	ret = userns_map_uid_gid(pid, "0 65534 1", "0 65534 1");
+	ASSERT_RETURN_VAL(ret == 0, ret);
+
+	/* Tell child we are ready */
+	ret = eventfd_write(efd, 1);
+	ASSERT_RETURN_VAL(ret == 0, ret);
+
+	ret = waitpid(pid, &status, 0);
+	ASSERT_RETURN_VAL(ret >= 0, ret);
+
+	close(efd);
+
+	return status == EXIT_SUCCESS ? TEST_OK : TEST_ERR;
+}
+
+static int kdbus_clone_userns_test(const char *bus,
+				   const char *name,
+				   struct kdbus_conn **conn_db,
+				   int expected_status)
+{
+	pid_t pid;
+	int ret = 0;
+	int status;
+
+	pid = fork();
+	ASSERT_RETURN_VAL(pid >= 0, -errno);
+
+	if (pid == 0) {
+		ret = prctl(PR_SET_PDEATHSIG, SIGKILL);
+		if (ret < 0)
+			_exit(EXIT_FAILURE);
+
+		ret = __kdbus_clone_userns_test(bus, name, conn_db,
+						expected_status);
+		_exit(ret);
+	}
+
+	/*
+	 * Receive in the original (root privileged) user namespace,
+	 * must fail with -ETIMEDOUT.
+	 */
+	ret = kdbus_msg_recv_poll(conn_db[0], 100, NULL, NULL);
+	ASSERT_RETURN_VAL(ret == -ETIMEDOUT, ret);
+
+	ret = waitpid(pid, &status, 0);
+	ASSERT_RETURN_VAL(ret >= 0, ret);
+
+	return (status == EXIT_SUCCESS) ? TEST_OK : TEST_ERR;
+}
+
+int kdbus_test_policy_ns(struct kdbus_test_env *env)
+{
+	int i;
+	int ret;
+	struct kdbus_conn *activator = NULL;
+	struct kdbus_conn *policy_holder = NULL;
+	char *bus = env->buspath;
+
+	ret = test_is_capable(CAP_SETUID, CAP_SETGID, -1);
+	ASSERT_RETURN(ret >= 0);
+
+	/* no enough privileges, SKIP test */
+	if (!ret)
+		return TEST_SKIP;
+
+	/* we require user-namespaces */
+	if (access("/proc/self/uid_map", F_OK) != 0)
+		return TEST_SKIP;
+
+	/* uids/gids must be mapped */
+	if (!all_uids_gids_are_mapped())
+		return TEST_SKIP;
+
+	conn_db = calloc(MAX_CONN, sizeof(struct kdbus_conn *));
+	ASSERT_RETURN(conn_db);
+
+	memset(conn_db, 0, MAX_CONN * sizeof(struct kdbus_conn *));
+
+	conn_db[0] = kdbus_hello(bus, 0, NULL, 0);
+	ASSERT_RETURN(conn_db[0]);
+
+	ret = kdbus_add_match_empty(conn_db[0]);
+	ASSERT_RETURN(ret == 0);
+
+	ret = kdbus_fork_test_by_id(bus, conn_db, -EPERM, -EPERM);
+	ASSERT_EXIT(ret == 0);
+
+	ret = kdbus_register_policy_holder(bus, POLICY_NAME,
+					   &policy_holder);
+	ASSERT_RETURN(ret == 0);
+
+	/* Try to register the same name with an activator */
+	ret = kdbus_register_same_activator(bus, POLICY_NAME,
+					    &activator);
+	ASSERT_RETURN(ret == 0);
+
+	/* Acquire POLICY_NAME */
+	ret = kdbus_name_acquire(conn_db[0], POLICY_NAME, NULL);
+	ASSERT_RETURN(ret == 0);
+
+	ret = kdbus_normal_test(bus, POLICY_NAME, conn_db);
+	ASSERT_RETURN(ret == 0);
+
+	ret = kdbus_list(conn_db[0], KDBUS_LIST_NAMES |
+				     KDBUS_LIST_UNIQUE |
+				     KDBUS_LIST_ACTIVATORS |
+				     KDBUS_LIST_QUEUED);
+	ASSERT_RETURN(ret == 0);
+
+	ret = kdbus_fork_test(bus, POLICY_NAME, conn_db, EXIT_SUCCESS);
+	ASSERT_RETURN(ret == 0);
+
+	/*
+	 * children connections are able to talk to conn_db[0] since
+	 * current POLICY_NAME TALK type is KDBUS_POLICY_ACCESS_WORLD,
+	 * so expect EXIT_SUCCESS when sending from child. However,
+	 * since the child's connection does not own any well-known
+	 * name, The parent connection conn_db[0] should fail with
+	 * -EPERM but since it is a privileged bus user the TALK is
+	 *  allowed.
+	 */
+	ret = kdbus_fork_test_by_id(bus, conn_db,
+				    EXIT_SUCCESS, EXIT_SUCCESS);
+	ASSERT_EXIT(ret == 0);
+
+	/*
+	 * Connections that can talk are perhaps being destroyed now.
+	 * Restrict the policy and purge cache entries where the
+	 * conn_db[0] is the destination.
+	 *
+	 * Now only connections with uid == 0 are allowed to talk.
+	 */
+	ret = kdbus_set_policy_talk(policy_holder, POLICY_NAME,
+				    geteuid(), KDBUS_POLICY_ACCESS_USER);
+	ASSERT_RETURN(ret == 0);
+
+	/*
+	 * Testing connections (FORK+DROP) again:
+	 * After setting the policy re-check connections
+	 * we expect the children to fail with -EPERM
+	 */
+	ret = kdbus_fork_test(bus, POLICY_NAME, conn_db, -EPERM);
+	ASSERT_RETURN(ret == 0);
+
+	/*
+	 * Now expect that both parent and child to fail.
+	 *
+	 * Child should fail with -EPERM since we just restricted
+	 * the POLICY_NAME TALK to uid 0 and its uid is 65534.
+	 *
+	 * Since the parent's connection will timeout when receiving
+	 * from the child, we never continue. FWIW just put -EPERM.
+	 */
+	ret = kdbus_fork_test_by_id(bus, conn_db, -EPERM, -EPERM);
+	ASSERT_EXIT(ret == 0);
+
+	/* Check if the name can be reached in a new userns */
+	ret = kdbus_clone_userns_test(bus, POLICY_NAME, conn_db, -EPERM);
+	ASSERT_RETURN(ret == 0);
+
+	for (i = 0; i < MAX_CONN; i++)
+		kdbus_conn_free(conn_db[i]);
+
+	kdbus_conn_free(activator);
+	kdbus_conn_free(policy_holder);
+
+	free(conn_db);
+
+	return ret;
+}