The test is pretty basic: - create a virtual uhid device that no userspace will like (to not mess up the running system) - attach a BPF prog to it - open the matching hidraw node - inject one event and check: * that the BPF program can do something on the event stream * can modify the event stream - add another test where we attach/detach BPF programs to see if we get errors
Signed-off-by: Benjamin Tissoires benjamin.tissoires@redhat.com
---
changes in v5: - use of the HID device system id instead of fd - attach to HID device with the new API - add attach/detach test
changes in v4: - manually retrieve the hidraw node from the sysfs (we can't get it for free from BPF) - use the new API
changes in v3: - squashed "hid: rely on uhid event to know if a test device is ready" into this one - add selftests bpf VM config changes - s/hidraw_ino/hidraw_number/
changes in v2: - split the series by bpf/libbpf/hid/selftests and samples --- tools/testing/selftests/bpf/config | 3 + tools/testing/selftests/bpf/prog_tests/hid.c | 669 +++++++++++++++++++ tools/testing/selftests/bpf/progs/hid.c | 45 ++ 3 files changed, 717 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/hid.c create mode 100644 tools/testing/selftests/bpf/progs/hid.c
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 08c6e5a66d87..64205150627d 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -54,3 +54,6 @@ CONFIG_NF_DEFRAG_IPV6=y CONFIG_NF_CONNTRACK=y CONFIG_USERFAULTFD=y CONFIG_FPROBE=y +CONFIG_HID=y +CONFIG_HIDRAW=y +CONFIG_UHID=y diff --git a/tools/testing/selftests/bpf/prog_tests/hid.c b/tools/testing/selftests/bpf/prog_tests/hid.c new file mode 100644 index 000000000000..719d220c8d86 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/hid.c @@ -0,0 +1,669 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Red Hat */ +#include <test_progs.h> +#include <testing_helpers.h> +#include "hid.skel.h" + +#include <fcntl.h> +#include <fnmatch.h> +#include <dirent.h> +#include <poll.h> +#include <stdbool.h> +#include <linux/uhid.h> + +static unsigned char rdesc[] = { + 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ + 0x09, 0x21, /* Usage (Vendor Usage 0x21) */ + 0xa1, 0x01, /* COLLECTION (Application) */ + 0x09, 0x01, /* Usage (Vendor Usage 0x01) */ + 0xa1, 0x00, /* COLLECTION (Physical) */ + 0x85, 0x01, /* REPORT_ID (1) */ + 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ + 0x19, 0x01, /* USAGE_MINIMUM (1) */ + 0x29, 0x03, /* USAGE_MAXIMUM (3) */ + 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ + 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ + 0x95, 0x03, /* REPORT_COUNT (3) */ + 0x75, 0x01, /* REPORT_SIZE (1) */ + 0x81, 0x02, /* INPUT (Data,Var,Abs) */ + 0x95, 0x01, /* REPORT_COUNT (1) */ + 0x75, 0x05, /* REPORT_SIZE (5) */ + 0x81, 0x01, /* INPUT (Cnst,Var,Abs) */ + 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ + 0x09, 0x30, /* USAGE (X) */ + 0x09, 0x31, /* USAGE (Y) */ + 0x15, 0x81, /* LOGICAL_MINIMUM (-127) */ + 0x25, 0x7f, /* LOGICAL_MAXIMUM (127) */ + 0x75, 0x10, /* REPORT_SIZE (16) */ + 0x95, 0x02, /* REPORT_COUNT (2) */ + 0x81, 0x06, /* INPUT (Data,Var,Rel) */ + + 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ + 0x19, 0x01, /* USAGE_MINIMUM (1) */ + 0x29, 0x03, /* USAGE_MAXIMUM (3) */ + 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ + 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ + 0x95, 0x03, /* REPORT_COUNT (3) */ + 0x75, 0x01, /* REPORT_SIZE (1) */ + 0x91, 0x02, /* Output (Data,Var,Abs) */ + 0x95, 0x01, /* REPORT_COUNT (1) */ + 0x75, 0x05, /* REPORT_SIZE (5) */ + 0x91, 0x01, /* Output (Cnst,Var,Abs) */ + + 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ + 0x19, 0x06, /* USAGE_MINIMUM (6) */ + 0x29, 0x08, /* USAGE_MAXIMUM (8) */ + 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ + 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ + 0x95, 0x03, /* REPORT_COUNT (3) */ + 0x75, 0x01, /* REPORT_SIZE (1) */ + 0xb1, 0x02, /* Feature (Data,Var,Abs) */ + 0x95, 0x01, /* REPORT_COUNT (1) */ + 0x75, 0x05, /* REPORT_SIZE (5) */ + 0x91, 0x01, /* Output (Cnst,Var,Abs) */ + + 0xc0, /* END_COLLECTION */ + 0xc0, /* END_COLLECTION */ +}; + +struct attach_prog_args { + int prog_fd; + unsigned int hid; + int retval; +}; + +static pthread_mutex_t uhid_started_mtx = PTHREAD_MUTEX_INITIALIZER; +static pthread_cond_t uhid_started = PTHREAD_COND_INITIALIZER; + +/* no need to protect uhid_stopped, only one thread accesses it */ +static bool uhid_stopped; + +static int uhid_write(int fd, const struct uhid_event *ev) +{ + ssize_t ret; + + ret = write(fd, ev, sizeof(*ev)); + if (ret < 0) { + fprintf(stderr, "Cannot write to uhid: %m\n"); + return -errno; + } else if (ret != sizeof(*ev)) { + fprintf(stderr, "Wrong size written to uhid: %zd != %zu\n", + ret, sizeof(ev)); + return -EFAULT; + } else { + return 0; + } +} + +static int create(int fd, int rand_nb) +{ + struct uhid_event ev; + char buf[25]; + + sprintf(buf, "test-uhid-device-%d", rand_nb); + + memset(&ev, 0, sizeof(ev)); + ev.type = UHID_CREATE; + strcpy((char *)ev.u.create.name, buf); + ev.u.create.rd_data = rdesc; + ev.u.create.rd_size = sizeof(rdesc); + ev.u.create.bus = BUS_USB; + ev.u.create.vendor = 0x0001; + ev.u.create.product = 0x0a37; + ev.u.create.version = 0; + ev.u.create.country = 0; + + sprintf(buf, "%d", rand_nb); + strcpy((char *)ev.u.create.phys, buf); + + return uhid_write(fd, &ev); +} + +static void destroy(int fd) +{ + struct uhid_event ev; + + memset(&ev, 0, sizeof(ev)); + ev.type = UHID_DESTROY; + + uhid_write(fd, &ev); +} + +static int uhid_event(int fd) +{ + struct uhid_event ev; + ssize_t ret; + + memset(&ev, 0, sizeof(ev)); + ret = read(fd, &ev, sizeof(ev)); + if (ret == 0) { + fprintf(stderr, "Read HUP on uhid-cdev\n"); + return -EFAULT; + } else if (ret < 0) { + fprintf(stderr, "Cannot read uhid-cdev: %m\n"); + return -errno; + } else if (ret != sizeof(ev)) { + fprintf(stderr, "Invalid size read from uhid-dev: %zd != %zu\n", + ret, sizeof(ev)); + return -EFAULT; + } + + switch (ev.type) { + case UHID_START: + pthread_mutex_lock(&uhid_started_mtx); + pthread_cond_signal(&uhid_started); + pthread_mutex_unlock(&uhid_started_mtx); + + fprintf(stderr, "UHID_START from uhid-dev\n"); + break; + case UHID_STOP: + uhid_stopped = true; + + fprintf(stderr, "UHID_STOP from uhid-dev\n"); + break; + case UHID_OPEN: + fprintf(stderr, "UHID_OPEN from uhid-dev\n"); + break; + case UHID_CLOSE: + fprintf(stderr, "UHID_CLOSE from uhid-dev\n"); + break; + case UHID_OUTPUT: + fprintf(stderr, "UHID_OUTPUT from uhid-dev\n"); + break; + case UHID_GET_REPORT: + fprintf(stderr, "UHID_GET_REPORT from uhid-dev\n"); + break; + case UHID_SET_REPORT: + fprintf(stderr, "UHID_SET_REPORT from uhid-dev\n"); + break; + default: + fprintf(stderr, "Invalid event from uhid-dev: %u\n", ev.type); + } + + return 0; +} + +static void *read_uhid_events_thread(void *arg) +{ + int fd = *(int *)arg; + struct pollfd pfds[1]; + int ret = 0; + + pfds[0].fd = fd; + pfds[0].events = POLLIN; + + uhid_stopped = false; + + while (!uhid_stopped) { + ret = poll(pfds, 1, 100); + if (ret < 0) { + fprintf(stderr, "Cannot poll for fds: %m\n"); + break; + } + if (pfds[0].revents & POLLIN) { + ret = uhid_event(fd); + if (ret) + break; + } + } + + return (void *)(long)ret; +} + +static int uhid_start_listener(pthread_t *tid, int uhid_fd) +{ + int fd = uhid_fd; + + pthread_mutex_lock(&uhid_started_mtx); + if (CHECK_FAIL(pthread_create(tid, NULL, read_uhid_events_thread, + (void *)&fd))) { + pthread_mutex_unlock(&uhid_started_mtx); + close(fd); + return -EIO; + } + pthread_cond_wait(&uhid_started, &uhid_started_mtx); + pthread_mutex_unlock(&uhid_started_mtx); + + return 0; +} + +static int send_event(int fd, u8 *buf, size_t size) +{ + struct uhid_event ev; + + if (size > sizeof(ev.u.input.data)) + return -E2BIG; + + memset(&ev, 0, sizeof(ev)); + ev.type = UHID_INPUT2; + ev.u.input2.size = size; + + memcpy(ev.u.input2.data, buf, size); + + return uhid_write(fd, &ev); +} + +static int setup_uhid(int rand_nb) +{ + int fd; + const char *path = "/dev/uhid"; + int ret; + + fd = open(path, O_RDWR | O_CLOEXEC); + if (!ASSERT_GE(fd, 0, "open uhid-cdev")) + return -EPERM; + + ret = create(fd, rand_nb); + if (!ASSERT_OK(ret, "create uhid device")) { + close(fd); + return -EPERM; + } + + return fd; +} + +static bool match_sysfs_device(int dev_id, const char *workdir, struct dirent *dir) +{ + const char *target = "0003:0001:0A37.*"; + char phys[512]; + char uevent[1024]; + char temp[512]; + int fd, nread; + bool found = false; + + if (fnmatch(target, dir->d_name, 0)) + return false; + + /* we found the correct VID/PID, now check for phys */ + sprintf(uevent, "%s/%s/uevent", workdir, dir->d_name); + + fd = open(uevent, O_RDONLY | O_NONBLOCK); + if (fd < 0) + return false; + + sprintf(phys, "PHYS=%d", dev_id); + + nread = read(fd, temp, ARRAY_SIZE(temp)); + if (nread > 0 && (strstr(temp, phys)) != NULL) + found = true; + + close(fd); + + return found; +} + +static int get_hid_id(int dev_id) +{ + const char *workdir = "/sys/devices/virtual/misc/uhid"; + const char *str_id; + DIR *d; + struct dirent *dir; + int found = -1; + + /* it would be nice to be able to use nftw, but the no_alu32 target doesn't support it */ + + d = opendir(workdir); + if (d) { + while ((dir = readdir(d)) != NULL) { + if (!match_sysfs_device(dev_id, workdir, dir)) + continue; + + str_id = dir->d_name + sizeof("0003:0001:0A37."); + found = (int)strtol(str_id, NULL, 16); + + break; + } + closedir(d); + } + + return found; +} + +static int get_hidraw(int dev_id) +{ + const char *workdir = "/sys/devices/virtual/misc/uhid"; + char sysfs[1024]; + DIR *d, *subd; + struct dirent *dir, *subdir; + int i, found = -1; + + /* retry 5 times in case the system is loaded */ + for (i = 5; i > 0; i--) { + usleep(10); + d = opendir(workdir); + + if (!d) + continue; + + while ((dir = readdir(d)) != NULL) { + if (!match_sysfs_device(dev_id, workdir, dir)) + continue; + + sprintf(sysfs, "%s/%s/hidraw", workdir, dir->d_name); + + subd = opendir(sysfs); + if (!subd) + continue; + + while ((subdir = readdir(subd)) != NULL) { + if (fnmatch("hidraw*", subdir->d_name, 0)) + continue; + + found = atoi(subdir->d_name + strlen("hidraw")); + } + + closedir(subd); + + if (found > 0) + break; + } + closedir(d); + } + + return found; +} + +static int open_hidraw(int dev_id) +{ + int hidraw_number; + char hidraw_path[64] = { 0 }; + + hidraw_number = get_hidraw(dev_id); + if (hidraw_number < 0) + return hidraw_number; + + /* open hidraw node to check the other side of the pipe */ + sprintf(hidraw_path, "/dev/hidraw%d", hidraw_number); + return open(hidraw_path, O_RDWR | O_NONBLOCK); +} + +struct test_params { + struct hid *skel; + int hidraw_fd; +}; + +static int prep_test(int dev_id, const char *prog_name, struct test_params *test_data) +{ + struct hid *hid_skel = NULL; + struct bpf_program *prog = NULL; + char buf[64] = {0}; + int hidraw_fd = -1; + int hid_id, attach_fd, err = -EINVAL; + struct attach_prog_args args = { + .retval = -1, + }; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); + + /* locate the uevent file of the created device */ + hid_id = get_hid_id(dev_id); + if (!ASSERT_GE(hid_id, 0, "locate uhid device id")) + goto cleanup; + + args.hid = hid_id; + + hid_skel = hid__open(); + if (!ASSERT_OK_PTR(hid_skel, "hid_skel_open")) + goto cleanup; + + prog = bpf_object__find_program_by_name(*hid_skel->skeleton->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "find_prog_by_name")) + goto cleanup; + + bpf_program__set_autoload(prog, true); + + err = hid__load(hid_skel); + if (!ASSERT_OK(err, "hid_skel_load")) + goto cleanup; + + attach_fd = bpf_program__fd(hid_skel->progs.attach_prog); + if (!ASSERT_GE(attach_fd, 0, "locate attach_prog")) { + err = attach_fd; + goto cleanup; + } + + args.prog_fd = bpf_program__fd(prog); + err = bpf_prog_test_run_opts(attach_fd, &tattr); + snprintf(buf, sizeof(buf), "attach_hid(%s)", prog_name); + if (!ASSERT_EQ(args.retval, 0, buf)) + goto cleanup; + + hidraw_fd = open_hidraw(dev_id); + if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw")) + goto cleanup; + + test_data->skel = hid_skel; + test_data->hidraw_fd = hidraw_fd; + + return 0; + + cleanup: + if (hidraw_fd >= 0) + close(hidraw_fd); + + hid__destroy(hid_skel); + + memset(test_data, 0, sizeof(*test_data)); + + return err; +} + +static void cleanup_test(struct test_params *test_data) +{ + if (!test_data) + return; + + if (test_data->hidraw_fd) + close(test_data->hidraw_fd); + + hid__destroy(test_data->skel); + + memset(test_data, 0, sizeof(*test_data)); +} + +/* + * Attach hid_first_event to the given uhid device, + * retrieve and open the matching hidraw node, + * inject one event in the uhid device, + * check that the program sees it and can change the data + */ +static int test_hid_raw_event(int uhid_fd, int dev_id) +{ + struct hid *hid_skel = NULL; + struct test_params params; + int err, hidraw_fd = -1; + u8 buf[10] = {0}; + int ret = -1; + + err = prep_test(dev_id, "hid_first_event", ¶ms); + if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)")) + goto cleanup; + + hid_skel = params.skel; + hidraw_fd = params.hidraw_fd; + + /* check that the program is correctly loaded */ + ASSERT_EQ(hid_skel->data->callback_check, 52, "callback_check1"); + ASSERT_EQ(hid_skel->data->callback2_check, 52, "callback2_check1"); + + /* inject one event */ + buf[0] = 1; + buf[1] = 42; + send_event(uhid_fd, buf, 6); + + /* check that hid_first_event() was executed */ + ASSERT_EQ(hid_skel->data->callback_check, 42, "callback_check1"); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(hidraw_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(err, 6, "read_hidraw")) + goto cleanup; + + if (!ASSERT_EQ(buf[0], 1, "hid_first_event")) + goto cleanup; + + if (!ASSERT_EQ(buf[2], 47, "hid_first_event")) + goto cleanup; + + /* inject another event */ + memset(buf, 0, sizeof(buf)); + buf[0] = 1; + buf[1] = 47; + send_event(uhid_fd, buf, 6); + + /* check that hid_first_event() was executed */ + ASSERT_EQ(hid_skel->data->callback_check, 47, "callback_check1"); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(hidraw_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(err, 6, "read_hidraw")) + goto cleanup; + + if (!ASSERT_EQ(buf[2], 52, "hid_first_event")) + goto cleanup; + + ret = 0; + +cleanup: + cleanup_test(¶ms); + + return ret; +} + +/* + * Ensures that we can attach/detach programs + */ +static int test_attach_detach(int uhid_fd, int dev_id) +{ + struct test_params params; + int err, hidraw_fd = -1; + u8 buf[10] = {0}; + int ret = -1; + + err = prep_test(dev_id, "hid_first_event", ¶ms); + if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)")) + goto cleanup; + + /* inject one event */ + buf[0] = 1; + buf[1] = 42; + send_event(uhid_fd, buf, 6); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(params.hidraw_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(err, 6, "read_hidraw_with_bpf")) + goto cleanup; + + if (!ASSERT_EQ(buf[0], 1, "hid_first_event")) + goto cleanup; + + if (!ASSERT_EQ(buf[2], 47, "hid_first_event")) + goto cleanup; + + /* pin the program and immediately unpin it */ +#define PIN_PATH "/sys/fs/bpf/hid_first_event" + bpf_program__pin(params.skel->progs.hid_first_event, PIN_PATH); + remove(PIN_PATH); +#undef PIN_PATH + usleep(100000); + + /* detach the program */ + cleanup_test(¶ms); + + hidraw_fd = open_hidraw(dev_id); + if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw")) + goto cleanup; + + /* inject another event */ + memset(buf, 0, sizeof(buf)); + buf[0] = 1; + buf[1] = 47; + send_event(uhid_fd, buf, 6); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(hidraw_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(err, 6, "read_hidraw_no_bpf")) + goto cleanup; + + if (!ASSERT_EQ(buf[0], 1, "event_no_bpf")) + goto cleanup; + + if (!ASSERT_EQ(buf[1], 47, "event_no_bpf")) + goto cleanup; + + if (!ASSERT_EQ(buf[2], 0, "event_no_bpf")) + goto cleanup; + + /* re-attach our program */ + + err = prep_test(dev_id, "hid_first_event", ¶ms); + if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)")) + goto cleanup; + + /* inject one event */ + memset(buf, 0, sizeof(buf)); + buf[0] = 1; + buf[1] = 42; + send_event(uhid_fd, buf, 6); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(params.hidraw_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(err, 6, "read_hidraw")) + goto cleanup; + + if (!ASSERT_EQ(buf[0], 1, "hid_first_event")) + goto cleanup; + + if (!ASSERT_EQ(buf[2], 47, "hid_first_event")) + goto cleanup; + + ret = 0; + +cleanup: + if (hidraw_fd >= 0) + close(hidraw_fd); + + cleanup_test(¶ms); + + return ret; +} + +void serial_test_hid_bpf(void) +{ + int err, uhid_fd; + void *uhid_err; + time_t t; + pthread_t tid; + int dev_id; + + /* initialize random number generator */ + srand((unsigned int)time(&t)); + + dev_id = rand() % 1024; + + uhid_fd = setup_uhid(dev_id); + if (!ASSERT_GE(uhid_fd, 0, "setup uhid")) + return; + + err = uhid_start_listener(&tid, uhid_fd); + ASSERT_OK(err, "uhid_start_listener"); + + /* start the tests! */ + err = test_hid_raw_event(uhid_fd, dev_id); + ASSERT_OK(err, "hid"); + err = test_attach_detach(uhid_fd, dev_id); + ASSERT_OK(err, "hid_attach_detach"); + + destroy(uhid_fd); + + pthread_join(tid, &uhid_err); + err = (int)(long)uhid_err; + CHECK_FAIL(err); +} diff --git a/tools/testing/selftests/bpf/progs/hid.c b/tools/testing/selftests/bpf/progs/hid.c new file mode 100644 index 000000000000..fc0a4241643a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/hid.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Red hat */ +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +char _license[] SEC("license") = "GPL"; + +extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx, + unsigned int offset, + const size_t __sz) __ksym; +extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym; + +struct attach_prog_args { + int prog_fd; + unsigned int hid; + int retval; +}; + +__u64 callback_check = 52; +__u64 callback2_check = 52; + +SEC("?fmod_ret/hid_bpf_device_event") +int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx) +{ + __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */); + + if (!rw_data) + return 0; /* EPERM check */ + + callback_check = rw_data[1]; + + rw_data[2] = rw_data[1] + 5; + + return 0; +} + +SEC("syscall") +int attach_prog(struct attach_prog_args *ctx) +{ + ctx->retval = hid_bpf_attach_prog(ctx->hid, + ctx->prog_fd, + 0); + return 0; +}