diff options
Diffstat (limited to 'tools/testing/selftests/uevent')
| -rw-r--r-- | tools/testing/selftests/uevent/Makefile | 17 | ||||
| -rw-r--r-- | tools/testing/selftests/uevent/config | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/uevent/uevent_filtering.c | 486 |
3 files changed, 505 insertions, 0 deletions
diff --git a/tools/testing/selftests/uevent/Makefile b/tools/testing/selftests/uevent/Makefile new file mode 100644 index 000000000000..f7baa9aa2932 --- /dev/null +++ b/tools/testing/selftests/uevent/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 +all: + +include ../lib.mk + +.PHONY: all clean + +BINARIES := uevent_filtering +CFLAGS += -Wl,-no-as-needed -Wall + +uevent_filtering: uevent_filtering.c ../kselftest.h ../kselftest_harness.h + $(CC) $(CFLAGS) $< -o $@ + +TEST_PROGS += $(BINARIES) +EXTRA_CLEAN := $(BINARIES) + +all: $(BINARIES) diff --git a/tools/testing/selftests/uevent/config b/tools/testing/selftests/uevent/config new file mode 100644 index 000000000000..1038f4515be8 --- /dev/null +++ b/tools/testing/selftests/uevent/config @@ -0,0 +1,2 @@ +CONFIG_USER_NS=y +CONFIG_NET=y diff --git a/tools/testing/selftests/uevent/uevent_filtering.c b/tools/testing/selftests/uevent/uevent_filtering.c new file mode 100644 index 000000000000..f83391aa42cf --- /dev/null +++ b/tools/testing/selftests/uevent/uevent_filtering.c @@ -0,0 +1,486 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <linux/netlink.h> +#include <signal.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/prctl.h> +#include <sys/socket.h> +#include <sched.h> +#include <sys/eventfd.h> +#include <sys/stat.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "../kselftest.h" +#include "../kselftest_harness.h" + +#define __DEV_FULL "/sys/devices/virtual/mem/full/uevent" +#define __UEVENT_BUFFER_SIZE (2048 * 2) +#define __UEVENT_HEADER "add@/devices/virtual/mem/full" +#define __UEVENT_HEADER_LEN sizeof("add@/devices/virtual/mem/full") +#define __UEVENT_LISTEN_ALL -1 + +ssize_t read_nointr(int fd, void *buf, size_t count) +{ + ssize_t ret; + +again: + ret = read(fd, buf, count); + if (ret < 0 && errno == EINTR) + goto again; + + return ret; +} + +ssize_t write_nointr(int fd, const void *buf, size_t count) +{ + ssize_t ret; + +again: + ret = write(fd, buf, count); + if (ret < 0 && errno == EINTR) + goto again; + + return ret; +} + +int wait_for_pid(pid_t pid) +{ + int status, ret; + +again: + ret = waitpid(pid, &status, 0); + if (ret == -1) { + if (errno == EINTR) + goto again; + + return -1; + } + + if (ret != pid) + goto again; + + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) + return -1; + + return 0; +} + +static int uevent_listener(unsigned long post_flags, bool expect_uevent, + int sync_fd) +{ + int sk_fd, ret; + socklen_t sk_addr_len; + int fret = -1, rcv_buf_sz = __UEVENT_BUFFER_SIZE; + uint64_t sync_add = 1; + struct sockaddr_nl sk_addr = { 0 }, rcv_addr = { 0 }; + char buf[__UEVENT_BUFFER_SIZE] = { 0 }; + struct iovec iov = { buf, __UEVENT_BUFFER_SIZE }; + char control[CMSG_SPACE(sizeof(struct ucred))]; + struct msghdr hdr = { + &rcv_addr, sizeof(rcv_addr), &iov, 1, + control, sizeof(control), 0, + }; + + sk_fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, + NETLINK_KOBJECT_UEVENT); + if (sk_fd < 0) { + fprintf(stderr, "%s - Failed to open uevent socket\n", strerror(errno)); + return -1; + } + + ret = setsockopt(sk_fd, SOL_SOCKET, SO_RCVBUF, &rcv_buf_sz, + sizeof(rcv_buf_sz)); + if (ret < 0) { + fprintf(stderr, "%s - Failed to set socket options\n", strerror(errno)); + goto on_error; + } + + sk_addr.nl_family = AF_NETLINK; + sk_addr.nl_groups = __UEVENT_LISTEN_ALL; + + sk_addr_len = sizeof(sk_addr); + ret = bind(sk_fd, (struct sockaddr *)&sk_addr, sk_addr_len); + if (ret < 0) { + fprintf(stderr, "%s - Failed to bind socket\n", strerror(errno)); + goto on_error; + } + + ret = getsockname(sk_fd, (struct sockaddr *)&sk_addr, &sk_addr_len); + if (ret < 0) { + fprintf(stderr, "%s - Failed to retrieve socket name\n", strerror(errno)); + goto on_error; + } + + if ((size_t)sk_addr_len != sizeof(sk_addr)) { + fprintf(stderr, "Invalid socket address size\n"); + goto on_error; + } + + if (post_flags & CLONE_NEWUSER) { + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + fprintf(stderr, + "%s - Failed to unshare user namespace\n", + strerror(errno)); + goto on_error; + } + } + + if (post_flags & CLONE_NEWNET) { + ret = unshare(CLONE_NEWNET); + if (ret < 0) { + fprintf(stderr, + "%s - Failed to unshare network namespace\n", + strerror(errno)); + goto on_error; + } + } + + ret = write_nointr(sync_fd, &sync_add, sizeof(sync_add)); + close(sync_fd); + if (ret != sizeof(sync_add)) { + fprintf(stderr, "Failed to synchronize with parent process\n"); + goto on_error; + } + + fret = 0; + for (;;) { + ssize_t r; + + r = recvmsg(sk_fd, &hdr, 0); + if (r <= 0) { + fprintf(stderr, "%s - Failed to receive uevent\n", strerror(errno)); + ret = -1; + break; + } + + /* ignore libudev messages */ + if (memcmp(buf, "libudev", 8) == 0) + continue; + + /* ignore uevents we didn't trigger */ + if (memcmp(buf, __UEVENT_HEADER, __UEVENT_HEADER_LEN) != 0) + continue; + + if (!expect_uevent) { + fprintf(stderr, "Received unexpected uevent:\n"); + ret = -1; + } + + if (TH_LOG_ENABLED) { + /* If logging is enabled dump the received uevent. */ + (void)write_nointr(STDERR_FILENO, buf, r); + (void)write_nointr(STDERR_FILENO, "\n", 1); + } + + break; + } + +on_error: + close(sk_fd); + + return fret; +} + +int trigger_uevent(unsigned int times) +{ + int fd, ret; + unsigned int i; + + fd = open(__DEV_FULL, O_RDWR | O_CLOEXEC); + if (fd < 0) { + if (errno != ENOENT) + return -EINVAL; + + return -1; + } + + for (i = 0; i < times; i++) { + ret = write_nointr(fd, "add\n", sizeof("add\n") - 1); + if (ret < 0) { + fprintf(stderr, "Failed to trigger uevent\n"); + break; + } + } + close(fd); + + return ret; +} + +int set_death_signal(void) +{ + int ret; + pid_t ppid; + + ret = prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); + + /* Check whether we have been orphaned. */ + ppid = getppid(); + if (ppid == 1) { + pid_t self; + + self = getpid(); + ret = kill(self, SIGKILL); + } + + if (ret < 0) + return -1; + + return 0; +} + +static int do_test(unsigned long pre_flags, unsigned long post_flags, + bool expect_uevent, int sync_fd) +{ + int ret; + uint64_t wait_val; + pid_t pid; + sigset_t mask; + sigset_t orig_mask; + struct timespec timeout; + + sigemptyset(&mask); + sigaddset(&mask, SIGCHLD); + + ret = sigprocmask(SIG_BLOCK, &mask, &orig_mask); + if (ret < 0) { + fprintf(stderr, "%s- Failed to block SIGCHLD\n", strerror(errno)); + return -1; + } + + pid = fork(); + if (pid < 0) { + fprintf(stderr, "%s - Failed to fork() new process\n", strerror(errno)); + return -1; + } + + if (pid == 0) { + /* Make sure that we go away when our parent dies. */ + ret = set_death_signal(); + if (ret < 0) { + fprintf(stderr, "Failed to set PR_SET_PDEATHSIG to SIGKILL\n"); + _exit(EXIT_FAILURE); + } + + if (pre_flags & CLONE_NEWUSER) { + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + fprintf(stderr, + "%s - Failed to unshare user namespace\n", + strerror(errno)); + _exit(EXIT_FAILURE); + } + } + + if (pre_flags & CLONE_NEWNET) { + ret = unshare(CLONE_NEWNET); + if (ret < 0) { + fprintf(stderr, + "%s - Failed to unshare network namespace\n", + strerror(errno)); + _exit(EXIT_FAILURE); + } + } + + if (uevent_listener(post_flags, expect_uevent, sync_fd) < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + ret = read_nointr(sync_fd, &wait_val, sizeof(wait_val)); + if (ret != sizeof(wait_val)) { + fprintf(stderr, "Failed to synchronize with child process\n"); + _exit(EXIT_FAILURE); + } + + /* Trigger 10 uevents to account for the case where the kernel might + * drop some. + */ + ret = trigger_uevent(10); + if (ret < 0) + fprintf(stderr, "Failed triggering uevents\n"); + + /* Wait for 2 seconds before considering this failed. This should be + * plenty of time for the kernel to deliver the uevent even under heavy + * load. + */ + timeout.tv_sec = 2; + timeout.tv_nsec = 0; + +again: + ret = sigtimedwait(&mask, NULL, &timeout); + if (ret < 0) { + if (errno == EINTR) + goto again; + + if (!expect_uevent) + ret = kill(pid, SIGTERM); /* success */ + else + ret = kill(pid, SIGUSR1); /* error */ + if (ret < 0) + return -1; + } + + ret = wait_for_pid(pid); + if (ret < 0) + return -1; + + return ret; +} + +static void signal_handler(int sig) +{ + if (sig == SIGTERM) + _exit(EXIT_SUCCESS); + + _exit(EXIT_FAILURE); +} + +TEST(uevent_filtering) +{ + int ret, sync_fd; + struct sigaction act; + + if (geteuid()) { + TH_LOG("Uevent filtering tests require root privileges. Skipping test"); + _exit(KSFT_SKIP); + } + + ret = access(__DEV_FULL, F_OK); + EXPECT_EQ(0, ret) { + if (errno == ENOENT) { + TH_LOG(__DEV_FULL " does not exist. Skipping test"); + _exit(KSFT_SKIP); + } + + _exit(KSFT_FAIL); + } + + act.sa_handler = signal_handler; + act.sa_flags = 0; + sigemptyset(&act.sa_mask); + + ret = sigaction(SIGTERM, &act, NULL); + ASSERT_EQ(0, ret); + + sync_fd = eventfd(0, EFD_CLOEXEC); + ASSERT_GE(sync_fd, 0); + + /* + * Setup: + * - Open uevent listening socket in initial network namespace owned by + * initial user namespace. + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(0, 0, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - Open uevent listening socket in non-initial network namespace + * owned by initial user namespace. + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(CLONE_NEWNET, 0, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - unshare user namespace + * - Open uevent listening socket in initial network namespace + * owned by initial user namespace. + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(CLONE_NEWUSER, 0, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - Open uevent listening socket in non-initial network namespace + * owned by non-initial user namespace. + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives no uevent + */ + ret = do_test(CLONE_NEWUSER | CLONE_NEWNET, 0, false, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - Open uevent listening socket in initial network namespace + * owned by initial user namespace. + * - unshare network namespace + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(0, CLONE_NEWNET, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - Open uevent listening socket in initial network namespace + * owned by initial user namespace. + * - unshare user namespace + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(0, CLONE_NEWUSER, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + + /* + * Setup: + * - Open uevent listening socket in initial network namespace + * owned by initial user namespace. + * - unshare user namespace + * - unshare network namespace + * - Trigger uevent in initial network namespace owned by initial user + * namespace. + * Expected Result: + * - uevent listening socket receives uevent + */ + ret = do_test(0, CLONE_NEWUSER | CLONE_NEWNET, true, sync_fd); + ASSERT_EQ(0, ret) { + goto do_cleanup; + } + +do_cleanup: + close(sync_fd); +} + +TEST_HARNESS_MAIN |