We add 3 new tests: - first, we make sure we can prevent the raw_request to happen - second, we make sure that we can detect that a given hidraw client was actually doing the request, and for that client only, call ourself hid_bpf_hw_request(), returning a custom value - last, we ensure that we can not loop between hooks for hid_hw_raw_request() and manual calls to hid_bpf_hw_request() from that hook
Signed-off-by: Benjamin Tissoires bentiss@kernel.org
---
no changes in v2 --- tools/testing/selftests/hid/hid_bpf.c | 109 ++++++++++++++++++++++++++++++++ tools/testing/selftests/hid/progs/hid.c | 79 +++++++++++++++++++++++ 2 files changed, 188 insertions(+)
diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c index 45e173db35bd..f97d56337d8a 100644 --- a/tools/testing/selftests/hid/hid_bpf.c +++ b/tools/testing/selftests/hid/hid_bpf.c @@ -470,6 +470,11 @@ static void detach_bpf(FIXTURE_DATA(hid_bpf) * self) close(self->hidraw_fd); self->hidraw_fd = 0;
+ if (!self->skel) + return; + + hid__detach(self->skel); + for (i = 0; i < ARRAY_SIZE(self->hid_links); i++) { if (self->hid_links[i]) bpf_link__destroy(self->hid_links[i]); @@ -575,6 +580,8 @@ static void load_programs(const struct test_program programs[], programs[i].name + 4); }
+ hid__attach(self->skel); + self->hidraw_fd = open_hidraw(self->dev_id); ASSERT_GE(self->hidraw_fd, 0) TH_LOG("open_hidraw"); } @@ -919,6 +926,108 @@ TEST_F(hid_bpf, test_hid_user_raw_request_call) ASSERT_EQ(args.data[1], 2); }
+/* + * Call hid_hw_raw_request against the given uhid device, + * check that the program is called and prevents the + * call to uhid. + */ +TEST_F(hid_bpf, test_hid_filter_raw_request_call) +{ + const struct test_program progs[] = { + { .name = "hid_test_filter_raw_request" }, + }; + __u8 buf[10] = {0}; + int err; + + LOAD_PROGRAMS(progs); + + /* first check that we did not attach to device_event */ + + /* inject one event */ + buf[0] = 1; + buf[1] = 42; + uhid_send_event(_metadata, self->uhid_fd, buf, 6); + + /* read the data from hidraw */ + memset(buf, 0, sizeof(buf)); + err = read(self->hidraw_fd, buf, sizeof(buf)); + ASSERT_EQ(err, 6) TH_LOG("read_hidraw"); + ASSERT_EQ(buf[0], 1); + ASSERT_EQ(buf[1], 42); + ASSERT_EQ(buf[2], 0) TH_LOG("leftovers_from_previous_test"); + + /* now check that our program is preventing hid_hw_raw_request() */ + + /* emit hid_hw_raw_request from hidraw */ + /* Get Feature */ + memset(buf, 0, sizeof(buf)); + buf[0] = 0x1; /* Report Number */ + err = ioctl(self->hidraw_fd, HIDIOCGFEATURE(sizeof(buf)), buf); + ASSERT_LT(err, 0) TH_LOG("unexpected success while reading HIDIOCGFEATURE: %d", err); + ASSERT_EQ(errno, 20) TH_LOG("unexpected error code while reading HIDIOCGFEATURE: %d", + errno); + + /* remove our bpf program and check that we can now emit commands */ + + /* detach the program */ + detach_bpf(self); + + self->hidraw_fd = open_hidraw(self->dev_id); + ASSERT_GE(self->hidraw_fd, 0) TH_LOG("open_hidraw"); + + err = ioctl(self->hidraw_fd, HIDIOCGFEATURE(sizeof(buf)), buf); + ASSERT_GE(err, 0) TH_LOG("error while reading HIDIOCGFEATURE: %d", err); +} + +/* + * Call hid_hw_raw_request against the given uhid device, + * check that the program is called and can issue the call + * to uhid and transform the answer. + */ +TEST_F(hid_bpf, test_hid_change_raw_request_call) +{ + const struct test_program progs[] = { + { .name = "hid_test_hidraw_raw_request" }, + }; + __u8 buf[10] = {0}; + int err; + + LOAD_PROGRAMS(progs); + + /* emit hid_hw_raw_request from hidraw */ + /* Get Feature */ + memset(buf, 0, sizeof(buf)); + buf[0] = 0x1; /* Report Number */ + err = ioctl(self->hidraw_fd, HIDIOCGFEATURE(sizeof(buf)), buf); + ASSERT_EQ(err, 3) TH_LOG("unexpected returned size while reading HIDIOCGFEATURE: %d", err); + + ASSERT_EQ(buf[0], 2); + ASSERT_EQ(buf[1], 3); + ASSERT_EQ(buf[2], 4); +} + +/* + * Call hid_hw_raw_request against the given uhid device, + * check that the program is not making infinite loops. + */ +TEST_F(hid_bpf, test_hid_infinite_loop_raw_request_call) +{ + const struct test_program progs[] = { + { .name = "hid_test_infinite_loop_raw_request" }, + }; + __u8 buf[10] = {0}; + int err; + + LOAD_PROGRAMS(progs); + + /* emit hid_hw_raw_request from hidraw */ + /* Get Feature */ + memset(buf, 0, sizeof(buf)); + buf[0] = 0x1; /* Report Number */ + err = ioctl(self->hidraw_fd, HIDIOCGFEATURE(sizeof(buf)), buf); + ASSERT_EQ(err, 3) TH_LOG("unexpected returned size while reading HIDIOCGFEATURE: %d", err); +} + /* * Attach hid_insert{0,1,2} to the given uhid device, * retrieve and open the matching hidraw node, diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c index 2e7e5a736dc6..0ad452fcca58 100644 --- a/tools/testing/selftests/hid/progs/hid.c +++ b/tools/testing/selftests/hid/progs/hid.c @@ -306,3 +306,82 @@ SEC(".struct_ops.link") struct hid_bpf_ops test_insert3 = { .hid_device_event = (void *)hid_test_insert3, }; + +SEC("?struct_ops/hid_hw_request") +int BPF_PROG(hid_test_filter_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum, + enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source) +{ + return -20; +} + +SEC(".struct_ops.link") +struct hid_bpf_ops test_filter_raw_request = { + .hid_hw_request = (void *)hid_test_filter_raw_request, +}; + +static struct file *current_file; + +SEC("fentry/hidraw_open") +int BPF_PROG(hidraw_open, struct inode *inode, struct file *file) +{ + current_file = file; + return 0; +} + +SEC("?struct_ops.s/hid_hw_request") +int BPF_PROG(hid_test_hidraw_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum, + enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source) +{ + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */); + int ret; + + if (!data) + return 0; /* EPERM check */ + + /* check if the incoming request comes from our hidraw operation */ + if (source == (__u64)current_file) { + data[0] = reportnum; + + ret = hid_bpf_hw_request(hctx, data, 2, rtype, reqtype); + if (ret != 2) + return -1; + data[0] = reportnum + 1; + data[1] = reportnum + 2; + data[2] = reportnum + 3; + return 3; + } + + return 0; +} + +SEC(".struct_ops.link") +struct hid_bpf_ops test_hidraw_raw_request = { + .hid_hw_request = (void *)hid_test_hidraw_raw_request, +}; + +SEC("?struct_ops.s/hid_hw_request") +int BPF_PROG(hid_test_infinite_loop_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum, + enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source) +{ + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */); + int ret; + + if (!data) + return 0; /* EPERM check */ + + /* always forward the request as-is to the device, hid-bpf should prevent + * infinite loops. + */ + data[0] = reportnum; + + ret = hid_bpf_hw_request(hctx, data, 2, rtype, reqtype); + if (ret == 2) + return 3; + + return 0; +} + +SEC(".struct_ops.link") +struct hid_bpf_ops test_infinite_loop_raw_request = { + .hid_hw_request = (void *)hid_test_infinite_loop_raw_request, +};