From patchwork Thu Apr 21 14:07:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 12821682 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97934C433F5 for ; Thu, 21 Apr 2022 14:08:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388977AbiDUOLL (ORCPT ); Thu, 21 Apr 2022 10:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388950AbiDUOLH (ORCPT ); Thu, 21 Apr 2022 10:11:07 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 961493A739 for ; 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Thu, 21 Apr 2022 14:08:02 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.194.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id 35DC140EC002; Thu, 21 Apr 2022 14:08:00 +0000 (UTC) From: Benjamin Tissoires To: Greg KH , Jiri Kosina , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, bpf@vger.kernel.org, Benjamin Tissoires Subject: [RFC bpf-next v4 7/7] selftests/bpf: add tests for the HID-bpf initial implementation Date: Thu, 21 Apr 2022 16:07:40 +0200 Message-Id: <20220421140740.459558-8-benjamin.tissoires@redhat.com> In-Reply-To: <20220421140740.459558-1-benjamin.tissoires@redhat.com> References: <20220421140740.459558-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC 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 Signed-off-by: Benjamin Tissoires --- 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 | 482 +++++++++++++++++++ tools/testing/selftests/bpf/progs/hid.c | 32 ++ 3 files changed, 517 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 763db63a3890..b983c76535f8 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -53,3 +53,6 @@ CONFIG_NF_DEFRAG_IPV4=y CONFIG_NF_DEFRAG_IPV6=y CONFIG_NF_CONNTRACK=y CONFIG_USERFAULTFD=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..624853fb0f7d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/hid.c @@ -0,0 +1,482 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Red Hat */ +#include +#include +#include "hid.skel.h" + +#include +#include +#include +#include +#include +#include + +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 */ +}; + +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 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 = 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_sysfs_fd(int dev_id) +{ + const char *workdir = "/sys/devices/virtual/misc/uhid"; + char uevent[1024]; + 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; + + sprintf(uevent, "%s/%s/uevent", workdir, dir->d_name); + + found = open(uevent, O_RDONLY | O_NONBLOCK); + if (found > 0) + 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; +} + +/* + * 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(struct hid *hid_skel, int uhid_fd, int sysfs_fd, int dev_id) +{ + int err, hidraw_number, hidraw_fd = -1; + char hidraw_path[64] = {0}; + u8 buf[10] = {0}; + int ret = -1; + + /* 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"); + + /* attach the first program */ + hid_skel->links.hid_first_event = + bpf_program__attach(hid_skel->progs.hid_first_event); + if (!ASSERT_OK_PTR(hid_skel->links.hid_first_event, + "attach_hid(hid_first_event)")) + return PTR_ERR(hid_skel->links.hid_first_event); + + hidraw_number = get_hidraw(dev_id); + if (!ASSERT_GE(hidraw_number, 0, "get_hidraw")) + goto cleanup; + + /* open hidraw node to check the other side of the pipe */ + sprintf(hidraw_path, "/dev/hidraw%d", hidraw_number); + hidraw_fd = open(hidraw_path, O_RDWR | O_NONBLOCK); + + if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw")) + goto cleanup; + + /* 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[2], 47, "hid_first_event")) + goto cleanup; + + /* inject another event */ + 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: + if (hidraw_fd >= 0) + close(hidraw_fd); + + hid__detach(hid_skel); + + return ret; +} + +void serial_test_hid_bpf(void) +{ + struct hid *hid_skel = NULL; + int err, uhid_fd, sysfs_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"); + + /* locate the uevent file of the created device */ + sysfs_fd = get_sysfs_fd(dev_id); + if (!ASSERT_GE(sysfs_fd, 0, "locate sysfs uhid device")) + goto cleanup; + + hid_skel = hid__open_and_load(); + if (!ASSERT_OK_PTR(hid_skel, "hid_skel_load")) + goto cleanup; + + /* start the tests! */ + err = test_hid_raw_event(hid_skel, uhid_fd, sysfs_fd, dev_id); + ASSERT_OK(err, "hid"); + +cleanup: + hid__destroy(hid_skel); + 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..37cc98ca206b --- /dev/null +++ b/tools/testing/selftests/bpf/progs/hid.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Red hat */ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +extern __u8 *hid_bpf_kfunc_get_data(struct hid_bpf_ctx *ctx, + unsigned int offset, + const size_t __sz) __ksym; +extern void hid_bpf_kfunc_data_release(__u8 *data) __ksym; + +__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, __s64 type) +{ + __u8 *rw_data = hid_bpf_kfunc_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; + + hid_bpf_kfunc_data_release(rw_data); + + return 0; +}