Discussion:
[RFC V2 PATCH 1/1] selinux-testsuite: Add binder tests
Richard Haines via Selinux
2018-05-20 18:25:06 UTC
Permalink
Add binder tests. See tests/binder/test_binder.c for details on
message flows to test security_binder*() functions.

Signed-off-by: Richard Haines <***@btinternet.com>
---
README.md | 8 +
defconfig | 7 +
policy/Makefile | 4 +
policy/test_binder.te | 96 +++++
tests/Makefile | 4 +
tests/binder/Makefile | 7 +
tests/binder/check_binder.c | 80 +++++
tests/binder/test | 89 +++++
tests/binder/test_binder.c | 685 ++++++++++++++++++++++++++++++++++++
9 files changed, 980 insertions(+)
create mode 100644 policy/test_binder.te
create mode 100644 tests/binder/Makefile
create mode 100644 tests/binder/check_binder.c
create mode 100644 tests/binder/test
create mode 100644 tests/binder/test_binder.c

diff --git a/README.md b/README.md
index c9f3b2b..60a249e 100644
--- a/README.md
+++ b/README.md
@@ -141,6 +141,14 @@ directory or you can follow these broken-out steps:
The broken-out steps allow you to run the tests multiple times without
loading policy each time.

+Note that if leaving the test policy in-place for further testing, the
+policy build process changes a boolean:
+ On policy load: setsebool allow_domain_fd_use=0
+ On policy unload: setsebool allow_domain_fd_use=1
+The consequence of this is that after a system reboot, the boolean
+defaults to true. Therefore if running the fdreceive or binder tests,
+reset the boolean to false, otherwise some tests will fail.
+
4) Review the test results.

As each test script is run, the name of the script will be displayed followed
diff --git a/defconfig b/defconfig
index 7dce8bc..c48d3cc 100644
--- a/defconfig
+++ b/defconfig
@@ -51,3 +51,10 @@ CONFIG_CRYPTO_USER=m
# This is enabled to test overlayfs SELinux integration.
# It is not required for SELinux operation itself.
CONFIG_OVERLAY_FS=m
+
+# Android binder implementations.
+# These are enabled to test the binder controls in
+# tests/binder; they are not required for SELinux operation itself.
+CONFIG_ANDROID=y
+CONFIG_ANDROID_BINDER_DEVICES="binder"
+CONFIG_ANDROID_BINDER_IPC=y
diff --git a/policy/Makefile b/policy/Makefile
index 5e07ee2..15e3a0c 100644
--- a/policy/Makefile
+++ b/policy/Makefile
@@ -63,6 +63,10 @@ ifeq ($(shell grep -q nnp_transition $(POLDEV)/include/support/all_perms.spt &&
export M4PARAM += -Dnnp_nosuid_transition_permission_defined
endif

+ifeq ($(shell grep -q binder $(POLDEV)/include/support/all_perms.spt && echo true),true)
+TARGETS += test_binder.te
+endif
+
ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6))
TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS))
endif
diff --git a/policy/test_binder.te b/policy/test_binder.te
new file mode 100644
index 0000000..3fd4dd5
--- /dev/null
+++ b/policy/test_binder.te
@@ -0,0 +1,96 @@
+
+attribute binderdomain;
+
+#
+################################## Manager ###################################
+#
+type test_binder_mgr_t;
+domain_type(test_binder_mgr_t)
+unconfined_runs_test(test_binder_mgr_t)
+typeattribute test_binder_mgr_t testdomain;
+typeattribute test_binder_mgr_t binderdomain;
+allow test_binder_mgr_t self:binder { set_context_mgr call };
+allow test_binder_mgr_t test_binder_provider_t:binder call;
+allow test_binder_mgr_t device_t:chr_file { ioctl open read write map };
+allow test_binder_mgr_t self:capability { sys_nice };
+allow test_binder_provider_t test_binder_mgr_t:fd use;
+fs_getattr_tmpfs(test_binder_mgr_t)
+allow test_binder_mgr_t tmpfs_t:file { read write open map };
+
+#
+########################## Manager no fd {use} ###############################
+#
+type test_binder_mgr_no_fd_t;
+domain_type(test_binder_mgr_no_fd_t)
+unconfined_runs_test(test_binder_mgr_no_fd_t)
+typeattribute test_binder_mgr_no_fd_t testdomain;
+typeattribute test_binder_mgr_no_fd_t binderdomain;
+allow test_binder_mgr_no_fd_t self:binder { set_context_mgr call };
+allow test_binder_mgr_no_fd_t test_binder_provider_t:binder { call };
+allow test_binder_mgr_no_fd_t device_t:chr_file { ioctl open read write map };
+allow test_binder_provider_t test_binder_mgr_no_fd_t:binder { call transfer impersonate };
+fs_getattr_tmpfs(test_binder_mgr_no_fd_t)
+allow test_binder_mgr_no_fd_t tmpfs_t:file { read write open map };
+
+#
+########################## Service Provider ################################
+#
+type test_binder_provider_t;
+domain_type(test_binder_provider_t)
+unconfined_runs_test(test_binder_provider_t)
+typeattribute test_binder_provider_t testdomain;
+typeattribute test_binder_provider_t binderdomain;
+allow test_binder_provider_t self:binder { call };
+allow test_binder_provider_t test_binder_mgr_t:binder { call transfer impersonate };
+allow test_binder_provider_t device_t:chr_file { ioctl open read write map };
+# For fstat:
+allow test_binder_provider_t device_t:chr_file getattr;
+fs_getattr_tmpfs(test_binder_provider_t)
+allow test_binder_provider_t tmpfs_t:file { read write open map };
+
+#
+#################### Service Provider no call ################################
+#
+type test_binder_provider_no_call_t;
+domain_type(test_binder_provider_no_call_t)
+unconfined_runs_test(test_binder_provider_no_call_t)
+typeattribute test_binder_provider_no_call_t testdomain;
+typeattribute test_binder_provider_no_call_t binderdomain;
+allow test_binder_provider_no_call_t device_t:chr_file { ioctl open read write map };
+fs_getattr_tmpfs(test_binder_provider_no_call_t)
+allow test_binder_provider_no_call_t tmpfs_t:file { read write open map };
+
+#
+#################### Service Provider no transfer #############################
+#
+type test_binder_provider_no_transfer_t;
+domain_type(test_binder_provider_no_transfer_t)
+unconfined_runs_test(test_binder_provider_no_transfer_t)
+typeattribute test_binder_provider_no_transfer_t testdomain;
+typeattribute test_binder_provider_no_transfer_t binderdomain;
+allow test_binder_provider_no_transfer_t test_binder_mgr_t:binder { call };
+allow test_binder_provider_no_transfer_t device_t:chr_file { ioctl open read write map };
+fs_getattr_tmpfs(test_binder_provider_no_transfer_t)
+allow test_binder_provider_no_transfer_t tmpfs_t:file { read write open map };
+
+#
+#################### Service Provider no impersonate ##########################
+#
+type test_binder_provider_no_im_t;
+domain_type(test_binder_provider_no_im_t)
+unconfined_runs_test(test_binder_provider_no_im_t)
+typeattribute test_binder_provider_no_im_t testdomain;
+typeattribute test_binder_provider_no_im_t binderdomain;
+allow test_binder_provider_no_im_t self:binder { call };
+allow test_binder_provider_no_im_t test_binder_mgr_t:binder { call transfer };
+allow test_binder_provider_no_im_t device_t:chr_file { ioctl open read write map };
+allow test_binder_provider_no_im_t test_binder_mgr_t:fd use;
+allow test_binder_provider_no_im_t device_t:chr_file getattr;
+fs_getattr_tmpfs(test_binder_provider_no_im_t)
+allow test_binder_provider_no_im_t tmpfs_t:file { read write open map };
+
+#
+############ Allow these domains to be entered from sysadm domain ############
+#
+miscfiles_domain_entry_test_files(binderdomain)
+userdom_sysadm_entry_spec_domtrans_to(binderdomain)
diff --git a/tests/Makefile b/tests/Makefile
index 27ed6eb..494b761 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -30,6 +30,10 @@ ifeq ($(shell grep -q getrlimit $(POLDEV)/include/support/all_perms.spt && echo
SUBDIRS += prlimit
endif

+ifeq ($(shell grep -q binder $(POLDEV)/include/support/all_perms.spt && echo true),true)
+SUBDIRS += binder
+endif
+
ifeq ($(shell grep "^SELINUX_INFINIBAND_ENDPORT_TEST=" infiniband_endport/ibendport_test.conf | cut -d'=' -f 2),1)
SUBDIRS += infiniband_endport
endif
diff --git a/tests/binder/Makefile b/tests/binder/Makefile
new file mode 100644
index 0000000..0d76723
--- /dev/null
+++ b/tests/binder/Makefile
@@ -0,0 +1,7 @@
+TARGETS = check_binder test_binder
+
+LDLIBS += -lselinux -lrt
+
+all: $(TARGETS)
+clean:
+ rm -f $(TARGETS)
diff --git a/tests/binder/check_binder.c b/tests/binder/check_binder.c
new file mode 100644
index 0000000..7b81a3d
--- /dev/null
+++ b/tests/binder/check_binder.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <linux/android/binder.h>
+
+static void usage(char *progname)
+{
+ fprintf(stderr,
+ "usage: %s [-v]\n"
+ "Where:\n\t"
+ "-v Print binder version.\n", progname);
+ exit(-1);
+}
+
+int main(int argc, char **argv)
+{
+ int opt, result, fd;
+ char *driver = "/dev/binder";
+ bool verbose;
+ void *mapped;
+ size_t mapsize = 1024;
+ struct binder_version vers;
+
+ while ((opt = getopt(argc, argv, "v")) != -1) {
+ switch (opt) {
+ case 'v':
+ verbose = true;
+ break;
+ default:
+ usage(argv[0]);
+ }
+ }
+
+ fd = open(driver, O_RDWR | O_CLOEXEC);
+ if (fd < 0) {
+ fprintf(stderr, "Cannot open: %s error: %s\n",
+ driver, strerror(errno));
+ exit(1);
+ }
+
+ /* Need this or no VMA error from kernel */
+ mapped = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (mapped == MAP_FAILED) {
+ fprintf(stderr, "mmap error: %s\n", strerror(errno));
+ close(fd);
+ exit(-1);
+ }
+
+ result = ioctl(fd, BINDER_VERSION, &vers);
+ if (result < 0) {
+ fprintf(stderr, "ioctl BINDER_VERSION: %s\n",
+ strerror(errno));
+ goto brexit;
+ }
+
+ if (vers.protocol_version != BINDER_CURRENT_PROTOCOL_VERSION) {
+ fprintf(stderr,
+ "Binder kernel version: %d differs from user space version: %d\n",
+ vers.protocol_version,
+ BINDER_CURRENT_PROTOCOL_VERSION);
+ result = 2;
+ goto brexit;
+ }
+
+ if (verbose)
+ fprintf(stderr, "Binder kernel version: %d\n",
+ vers.protocol_version);
+
+brexit:
+ munmap(mapped, mapsize);
+ close(fd);
+
+ return result;
+}
diff --git a/tests/binder/test b/tests/binder/test
new file mode 100644
index 0000000..86fab52
--- /dev/null
+++ b/tests/binder/test
@@ -0,0 +1,89 @@
+#!/usr/bin/perl
+use Test::More;
+
+BEGIN {
+ $basedir = $0;
+ $basedir =~ s|(.*)/[^/]*|$1|;
+
+ # allow binder info to be shown
+ $v = $ARGV[0];
+ if ($v) {
+ if ( $v ne "-v" ) {
+ plan skip_all => "Invalid option (use -v)";
+ }
+ }
+ else {
+ $v = " ";
+ }
+
+ # check if binder driver available and kernel/userspace versions.
+ $result = system("$basedir/check_binder 2> /dev/null");
+
+ if ( $result >> 8 eq 0 ) {
+ plan tests => 6;
+ }
+ elsif ( $result >> 8 eq 1 ) {
+ plan skip_all => "Binder not supported by kernel";
+ }
+ elsif ( $result >> 8 eq 2 ) {
+ plan skip_all => "Binder kernel/userspace versions differ";
+ }
+ else {
+ plan skip_all => "Error checking Binder driver";
+ }
+}
+
+if ( ( $pid = fork() ) == 0 ) {
+ exec "runcon -t test_binder_mgr_t $basedir/test_binder $v manager";
+}
+
+select( undef, undef, undef, 0.25 ); # Give it a moment to initialize.
+
+# 1 Verify that authorized provider can transact with the manager.
+$result =
+ system
+ "runcon -t test_binder_provider_t $basedir/test_binder $v -r 1 provider";
+ok( $result eq 0 );
+
+# 2 Verify that provider cannot call manager (no call perm).
+$result = system
+"runcon -t test_binder_provider_no_call_t $basedir/test_binder $v -r 2 provider 2>&1";
+ok( $result >> 8 eq 8 );
+
+# 3 Verify that provider cannot communicate with manager (no impersonate perm).
+$result = system
+"runcon -t test_binder_provider_no_im_t $basedir/test_binder $v -r 1 provider 2>&1";
+ok( $result >> 8 eq 103 );
+
+# 4 Verify that provider cannot communicate with manager (no transfer perm).
+$result = system
+"runcon -t test_binder_provider_no_transfer_t $basedir/test_binder $v -r 1 provider 2>&1";
+ok( $result >> 8 eq 8 );
+
+# Kill the manager.
+kill TERM, $pid;
+
+# 5 Verify that provider cannot become a manager (no set_context_mgr perm).
+$result =
+ system
+ "runcon -t test_binder_provider_t $basedir/test_binder $v manager 2>&1";
+ok( $result >> 8 eq 4 );
+
+# Start manager to test that selinux_binder_transfer_file() fails when fd { use } is denied by policy.
+if ( ( $pid = fork() ) == 0 ) {
+ exec "runcon -t test_binder_mgr_no_fd_t $basedir/test_binder $v manager";
+}
+
+select( undef, undef, undef, 0.25 ); # Give it a moment to initialize.
+
+# 6 Verify that authorized provider can communicate with the server, however the fd passed will not be valid for manager
+# domain and binder will return BR_FAILED_REPLY.
+$result =
+ system
+ "runcon -t test_binder_provider_t $basedir/test_binder $v provider -r 1 2>&1";
+ok( $result >> 8 eq 8 );
+
+# Kill the manager
+kill TERM, $pid;
+
+exit;
diff --git a/tests/binder/test_binder.c b/tests/binder/test_binder.c
new file mode 100644
index 0000000..919e568
--- /dev/null
+++ b/tests/binder/test_binder.c
@@ -0,0 +1,685 @@
+/*
+ * This is a simple binder Service Manager/Service Provider that only uses
+ * the raw ioctl commands to test the SELinux binder permissions:
+ * set_context_mgr, call, transfer, impersonate.
+ *
+ * Using binder test policy the following will be validated:
+ * security_binder_set_context_mgr() binder { set_context_mgr }
+ * security_binder_transaction() binder { call impersonate }
+ * security_binder_transfer_binder() binder { transfer }
+ * security_binder_transfer_file() fd { use }
+ *
+ * TODO security_binder_transfer_file() uses BPF if configured in kernel.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <selinux/selinux.h>
+#include <linux/android/binder.h>
+
+/* These are the Binder txn->code values used by the Service Provider and
+ * Manager to request/retrieve a binder handle.
+ */
+#define ADD_TEST_SERVICE 100 /* Sent by Service Provider */
+#define GET_TEST_SERVICE 101 /* Sent by Client */
+
+#define TEST_SERVICE_MANAGER_HANDLE 0
+
+static int binder_parse(int fd, uintptr_t ptr, size_t size, bool manager);
+
+static bool verbose;
+uint32_t sp_handle;
+static unsigned char *shm_base;
+static int shm_fd;
+static int shm_size = 32;
+
+static void usage(char *progname)
+{
+ fprintf(stderr,
+ "usage: %s [-r replies] [-v] manager | provider\n"
+ "Where:\n\t"
+ "-r Number of replies to expect from test - default 0.\n\t"
+ "-v Print context and command information.\n\t"
+ "manager Act as Service Manager.\n\t"
+ "service Act as Service Provider.\n"
+ "\nNote: Ensure this boolean command is run when "
+ "testing after a reboot:\n\t"
+ "setsebool allow_domain_fd_use=0\n", progname);
+ exit(-1);
+}
+
+/* Create a small piece of shared memory between the Manager and Service
+ * Provider to share a handle as explained in the do_service_manager()
+ * function.
+ */
+static void create_shm(bool manager)
+{
+ char *name = "sp_handle";
+
+ if (manager)
+ shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);
+ else
+ shm_fd = shm_open(name, O_RDONLY, 0666);
+ if (shm_fd < 0) {
+ fprintf(stderr, "%s shm_open: %s\n", __func__, strerror(errno));
+ exit(-1);
+ }
+
+ ftruncate(shm_fd, shm_size);
+
+ if (manager)
+ shm_base = mmap(0, shm_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+ shm_fd, 0);
+ else
+ shm_base = mmap(0, shm_size, PROT_READ, MAP_SHARED, shm_fd, 0);
+ if (shm_base == MAP_FAILED) {
+ fprintf(stderr, "%s mmap: %s\n", __func__, strerror(errno));
+ close(shm_fd);
+ exit(-1);
+ }
+}
+
+static const char *cmd_name(uint32_t cmd)
+{
+ switch (cmd) {
+ case BR_NOOP:
+ return "BR_NOOP";
+ case BR_TRANSACTION_COMPLETE:
+ return "BR_TRANSACTION_COMPLETE";
+ case BR_INCREFS:
+ return "BR_INCREFS";
+ case BR_ACQUIRE:
+ return "BR_ACQUIRE";
+ case BR_RELEASE:
+ return "BR_RELEASE";
+ case BR_DECREFS:
+ return "BR_DECREFS";
+ case BR_TRANSACTION:
+ return "BR_TRANSACTION";
+ case BR_REPLY:
+ return "BR_REPLY";
+ case BR_FAILED_REPLY:
+ return "BR_FAILED_REPLY";
+ case BR_DEAD_REPLY:
+ return "BR_DEAD_REPLY";
+ case BR_DEAD_BINDER:
+ return "BR_DEAD_BINDER";
+ case BR_ERROR:
+ return "BR_ERROR";
+ /* fallthrough */
+ default:
+ return "Unknown command";
+ }
+}
+
+static void print_trans_data(struct binder_transaction_data *txn_in)
+{
+ struct flat_binder_object *obj;
+ binder_size_t *offs = (binder_size_t *)
+ (uintptr_t)txn_in->data.ptr.offsets;
+ size_t count = txn_in->offsets_size / sizeof(binder_size_t);
+
+ printf("\thandle: %ld\n", (unsigned long)txn_in->target.handle);
+ printf("\tcookie: %lld\n", txn_in->cookie);
+ printf("\tcode: %d\n", txn_in->code);
+ switch (txn_in->flags) {
+ case TF_ONE_WAY:
+ printf("\tflag: TF_ONE_WAY\n");
+ break;
+ case TF_ROOT_OBJECT:
+ printf("\tflag: TF_ROOT_OBJECT\n");
+ break;
+ case TF_STATUS_CODE:
+ printf("\tflag: TF_STATUS_CODE\n");
+ break;
+ case TF_ACCEPT_FDS:
+ printf("\tflag: TF_ACCEPT_FDS\n");
+ break;
+ default:
+ printf("Unknown flag: %x\n", txn_in->flags);
+ return;
+ }
+ printf("\tsender pid: %u\n", txn_in->sender_pid);
+ printf("\tsender euid: %u\n", txn_in->sender_euid);
+ printf("\tdata_size: %llu\n", txn_in->data_size);
+ printf("\toffsets_size: %llu\n", txn_in->offsets_size);
+
+ while (count--) {
+ obj = (struct flat_binder_object *)
+ (((char *)(uintptr_t)txn_in->data.ptr.buffer) + *offs++);
+
+ switch (obj->hdr.type) {
+ case BINDER_TYPE_BINDER:
+ printf("\thdr: BINDER_TYPE_BINDER\n");
+ printf("\tbinder: %llx\n", obj->binder);
+ break;
+ case BINDER_TYPE_HANDLE:
+ printf("\thdr: BINDER_TYPE_HANDLE\n");
+ printf("\thandle: %x\n", obj->handle);
+ break;
+ case BINDER_TYPE_FD:
+ printf("\thdr: BINDER_TYPE_FD\n");
+ printf("\tfd: %x\n", obj->handle);
+ break;
+ default:
+ printf("Unknown header: %u\n", obj->hdr.type);
+ return;
+ }
+ printf("\tflags: priority: 0x%x accept FDS: %s\n",
+ obj->flags & FLAT_BINDER_FLAG_PRIORITY_MASK,
+ obj->flags & FLAT_BINDER_FLAG_ACCEPTS_FDS ? "YES" : "NO");
+ printf("\tcookie: %llx\n", obj->cookie);
+ }
+}
+
+/* If add a service provider, then obtain a handle for it and store in
+ * shared memory. The handle will then be used by the service provider
+ * process to contact the Manager for its file descriptor, thus triggering
+ * the 'impersonate' permission (as current_sid() != task_sid(from))
+ * It is done this way as being a cheapskate it saved adding code to the
+ * GET_TEST_SERVICE process plus running a Client as well. This achieves
+ * the same objective.
+ */
+static void do_service_manager(int fd, struct binder_transaction_data *txn_in)
+{
+ int result;
+ struct flat_binder_object *obj;
+ struct binder_write_read bwr;
+ uint32_t acmd[2];
+ binder_size_t *offs;
+
+ switch (txn_in->code) {
+ case ADD_TEST_SERVICE:
+ offs = (binder_size_t *)(uintptr_t)txn_in->data.ptr.offsets;
+
+ /* Get fbo that contains the Managers binder file descriptor. */
+ obj = (struct flat_binder_object *)
+ (((char *)(uintptr_t)txn_in->data.ptr.buffer) + *offs);
+
+ if (obj->hdr.type == BINDER_TYPE_HANDLE) {
+ sp_handle = obj->handle;
+ memcpy(shm_base, &sp_handle, sizeof(sp_handle));
+ if (verbose)
+ printf("Manager has BINDER_TYPE_HANDLE obj->handle: %d\n",
+ sp_handle);
+ } else {
+ fprintf(stderr, "Failed to obtain a handle\n");
+ exit(-1);
+ }
+
+ acmd[0] = BC_ACQUIRE;
+ acmd[1] = obj->handle;
+
+ memset(&bwr, 0, sizeof(bwr));
+ bwr.write_buffer = (uintptr_t)&acmd;
+ bwr.write_size = sizeof(acmd);
+
+ result = ioctl(fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr,
+ "ServiceProvider ioctl BINDER_WRITE_READ: %s\n",
+ strerror(errno));
+ exit(-1);
+ }
+
+ if (verbose)
+ printf("Manager acquired handle: %d for Service Provider\n",
+ sp_handle);
+ break;
+
+ case GET_TEST_SERVICE:
+ if (verbose)
+ printf("GET_TEST_SERVICE not supported\n");
+ break;
+ default:
+ fprintf(stderr, "Unknown txn->code: %d\n", txn_in->code);
+ exit(-1);
+ }
+}
+
+static void request_manager_fd(int fd, struct binder_transaction_data *txn_in)
+{
+ int result;
+ unsigned int writebuf[1024];
+ struct binder_fd_object obj;
+ struct binder_write_read bwr;
+ struct binder_transaction_data *txn;
+
+ if (txn_in->flags == TF_ONE_WAY) {
+ if (verbose)
+ printf("Manager no reply to BC_TRANSACTION as flags = TF_ONE_WAY\n");
+ return;
+ }
+
+ if (verbose)
+ printf("Manager sending BC_REPLY to obtain its FD\n");
+
+ writebuf[0] = BC_REPLY;
+ txn = (struct binder_transaction_data *)(&writebuf[1]);
+
+ memset(txn, 0, sizeof(*txn));
+ txn->target.handle = txn_in->target.handle;
+ txn->cookie = txn_in->cookie;
+ txn->code = txn_in->code;
+ txn->flags = TF_ACCEPT_FDS;
+ memset(&obj, 0, sizeof(struct binder_fd_object));
+ obj.hdr.type = BINDER_TYPE_FD;
+ obj.pad_flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
+ obj.cookie = txn->cookie;
+ /* The binder fd is used for testing as it allows policy to set
+ * whether the Service and Manager can be allowed access (fd use)
+ * or not. For example test_binder_mgr_t has:
+ * allow test_binder_service_t test_binder_mgr_t:fd use;
+ * whereas test_binder_mgr_no_fd_t does not allow this fd use.
+ *
+ * This also allows a check for the impersonate permission later
+ * as the Service Provider will use this (the Managers fd) to
+ * send a transaction.
+ */
+ obj.fd = fd;
+
+ if (verbose)
+ printf("Manager handle: %d and its FD: %d\n",
+ txn->target.handle, fd);
+
+ txn->data_size = sizeof(struct flat_binder_object);
+ txn->data.ptr.buffer = (uintptr_t)&obj;
+ txn->data.ptr.offsets = (uintptr_t)&obj +
+ sizeof(struct flat_binder_object);
+ txn->offsets_size = sizeof(binder_size_t);
+
+ memset(&bwr, 0, sizeof(bwr));
+ bwr.write_buffer = (uintptr_t)writebuf;
+ bwr.write_size = sizeof(writebuf[0]) + sizeof(*txn);
+
+ result = ioctl(fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr, "%s ioctl BINDER_WRITE_READ: %s\n",
+ __func__, strerror(errno));
+ exit(-1);
+ }
+}
+
+/* This retrieves the requested Managers file descriptor, then using this
+ * sends a simple transaction to trigger the impersonate permission.
+ */
+static void extract_fd_and_respond(struct binder_transaction_data *txn_in,
+ bool manager)
+{
+ int result;
+ uint32_t cmd;
+ struct stat sb;
+ struct binder_write_read bwr;
+ struct binder_fd_object *obj;
+ struct binder_transaction_data *txn;
+ unsigned int readbuf[32];
+ unsigned int writebuf[1024];
+ binder_size_t *offs = (binder_size_t *)
+ (uintptr_t)txn_in->data.ptr.offsets;
+
+ /* Get the bfdo that contains the Managers binder file descriptor. */
+ obj = (struct binder_fd_object *)
+ (((char *)(uintptr_t)txn_in->data.ptr.buffer) + *offs);
+
+ if (obj->hdr.type != BINDER_TYPE_FD) {
+ fprintf(stderr, "Header not BINDER_TYPE_FD: %d\n",
+ obj->hdr.type);
+ exit(100);
+ }
+
+ /* fstat this just to see if a valid fd */
+ result = fstat(obj->fd, &sb);
+ if (result < 0) {
+ fprintf(stderr, "Not a valid fd: %s\n", strerror(errno));
+ exit(101);
+ }
+
+ if (verbose)
+ printf("Service Provider retrieved Managers fd: %d st_dev: %ld\n",
+ obj->fd, sb.st_dev);
+
+ /* Send response using Managers fd to trigger impersonate check. */
+ writebuf[0] = BC_TRANSACTION;
+ txn = (struct binder_transaction_data *)(&writebuf[1]);
+ memset(txn, 0, sizeof(*txn));
+ /* Copy handle from the Manager */
+ memcpy(&txn->target.handle, shm_base, sizeof(uint32_t));
+
+ txn->cookie = 0;
+ txn->code = 0;
+ txn->flags = TF_ONE_WAY;
+
+ txn->data_size = 0;
+ txn->data.ptr.buffer = (uintptr_t)NULL;
+ txn->data.ptr.offsets = (uintptr_t)NULL;
+ txn->offsets_size = 0;
+
+ memset(&bwr, 0, sizeof(bwr));
+ bwr.write_buffer = (uintptr_t)writebuf;
+ bwr.write_size = sizeof(writebuf[0]) + sizeof(*txn);
+
+ bwr.read_size = sizeof(readbuf);
+ bwr.read_consumed = 0;
+ bwr.read_buffer = (uintptr_t)readbuf;
+
+ result = ioctl(obj->fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr,
+ "Service Provider ioctl BINDER_WRITE_READ: %s\n",
+ strerror(errno));
+ exit(102);
+ }
+
+ if (verbose)
+ printf("Service Provider read_consumed: %lld\n",
+ bwr.read_consumed);
+
+ cmd = binder_parse(obj->fd, (uintptr_t)readbuf,
+ bwr.read_consumed, manager);
+
+ if (verbose)
+ printf("Service Provider using Managers FD\n");
+
+ if (cmd == BR_FAILED_REPLY ||
+ cmd == BR_DEAD_REPLY ||
+ cmd == BR_DEAD_BINDER) {
+ fprintf(stderr,
+ "Failed response from Service Provider using Managers FD\n");
+ exit(103);
+ }
+}
+
+/* Parse response, reply as required and then return last CMD */
+static int binder_parse(int fd, uintptr_t ptr, size_t size, bool manager)
+{
+ uintptr_t end = ptr + (uintptr_t)size;
+ uint32_t cmd;
+
+ while (ptr < end) {
+ cmd = *(uint32_t *)ptr;
+ ptr += sizeof(uint32_t);
+
+ if (verbose)
+ printf("%s command: %s\n",
+ manager ? "Manager" : "Service Provider",
+ cmd_name(cmd));
+
+ switch (cmd) {
+ case BR_NOOP:
+ break;
+ case BR_TRANSACTION_COMPLETE:
+ break;
+ case BR_INCREFS:
+ case BR_ACQUIRE:
+ case BR_RELEASE:
+ case BR_DECREFS:
+ ptr += sizeof(struct binder_ptr_cookie);
+ break;
+ case BR_TRANSACTION: {
+ struct binder_transaction_data *txn =
+ (struct binder_transaction_data *)ptr;
+
+ if (verbose) {
+ printf("%s BR_TRANSACTION data:\n",
+ manager ? "Manager" : "Service Provider");
+ print_trans_data(txn);
+ }
+
+ if (manager) {
+ do_service_manager(fd, txn);
+ request_manager_fd(fd, txn);
+ }
+
+ ptr += sizeof(*txn);
+ break;
+ }
+ case BR_REPLY: {
+ struct binder_transaction_data *txn =
+ (struct binder_transaction_data *)ptr;
+
+ if (verbose) {
+ printf("%s BR_REPLY data:\n",
+ manager ? "Manager" : "Service Provider");
+ print_trans_data(txn);
+ }
+
+ /* Service Provider extracts the Manager fd, and responds */
+ if (!manager)
+ extract_fd_and_respond(txn, manager);
+
+ ptr += sizeof(*txn);
+ break;
+ }
+ case BR_DEAD_BINDER:
+ break;
+ case BR_FAILED_REPLY:
+ break;
+ case BR_DEAD_REPLY:
+ break;
+ case BR_ERROR:
+ ptr += sizeof(uint32_t);
+ break;
+ default:
+ if (verbose)
+ printf("%s Parsed unknown command: %d\n",
+ manager ? "Manager" : "Service Provider",
+ cmd);
+ exit(-1);
+ }
+ }
+
+ return cmd;
+}
+
+int main(int argc, char **argv)
+{
+ int opt, result, binder_fd, provider_replies = 0;
+ uint32_t cmd;
+ bool manager;
+ pid_t pid;
+ char *driver = "/dev/binder";
+ char *context;
+ void *map_base;
+ size_t map_size = 2048;
+ struct binder_write_read bwr;
+ struct flat_binder_object obj;
+ struct binder_transaction_data *txn;
+ unsigned int readbuf[32];
+ unsigned int writebuf[1024];
+
+
+ verbose = false;
+
+ while ((opt = getopt(argc, argv, "vr:")) != -1) {
+ switch (opt) {
+ case 'v':
+ verbose = true;
+ break;
+ case 'r':
+ provider_replies = atoi(optarg);
+ break;
+ default:
+ usage(argv[0]);
+ }
+ }
+
+ if ((argc - optind) != 1)
+ usage(argv[0]);
+
+ if (!strcmp(argv[optind], "manager"))
+ manager = true;
+ else if (!strcmp(argv[optind], "provider"))
+ manager = false;
+ else
+ usage(argv[0]);
+
+ binder_fd = open(driver, O_RDWR | O_CLOEXEC);
+ if (binder_fd < 0) {
+ fprintf(stderr, "Cannot open %s error: %s\n", driver,
+ strerror(errno));
+ exit(1);
+ }
+
+ map_base = mmap(NULL, map_size, PROT_READ, MAP_PRIVATE, binder_fd, 0);
+ if (map_base == MAP_FAILED) {
+ fprintf(stderr, "mmap error: %s\n", strerror(errno));
+ close(binder_fd);
+ exit(2);
+ }
+
+ /* Create the appropriate shared memory for passing the Service
+ * Providers handle from the Manager to the Service Provider for
+ * use in the impersonate tests. This saves adding a Client to
+ * do this job.
+ */
+ create_shm(manager);
+
+ /* Get our context and pid */
+ result = getcon(&context);
+ if (result < 0) {
+ fprintf(stderr, "Failed to obtain SELinux context\n");
+ result = 3;
+ goto brexit;
+ }
+ pid = getpid();
+
+ if (manager) { /* Service Manager */
+ if (verbose) {
+ printf("Manager PID: %d Process context:\n\t%s\n",
+ pid, context);
+ }
+
+ result = ioctl(binder_fd, BINDER_SET_CONTEXT_MGR, 0);
+ if (result < 0) {
+ fprintf(stderr,
+ "Failed to become context manager: %s\n",
+ strerror(errno));
+ result = 4;
+ goto brexit;
+ }
+
+ readbuf[0] = BC_ENTER_LOOPER;
+ bwr.write_size = sizeof(readbuf[0]);
+ bwr.write_consumed = 0;
+ bwr.write_buffer = (uintptr_t)readbuf;
+
+ bwr.read_size = 0;
+ bwr.read_consumed = 0;
+ bwr.read_buffer = 0;
+
+ result = ioctl(binder_fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr,
+ "Manager ioctl BINDER_WRITE_READ: %s\n",
+ strerror(errno));
+ result = 5;
+ goto brexit;
+ }
+
+ while (true) {
+ bwr.read_size = sizeof(readbuf);
+ bwr.read_consumed = 0;
+ bwr.read_buffer = (uintptr_t)readbuf;
+
+ result = ioctl(binder_fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr,
+ "Manager ioctl BINDER_WRITE_READ: %s\n",
+ strerror(errno));
+ result = 6;
+ goto brexit;
+ }
+
+ if (bwr.read_consumed == 0)
+ continue;
+
+ if (verbose)
+ printf("Manager read_consumed: %lld\n",
+ bwr.read_consumed);
+
+ cmd = binder_parse(binder_fd, (uintptr_t)readbuf,
+ bwr.read_consumed, manager);
+ }
+ } else { /* Service Provider */
+ if (verbose) {
+ printf("Service Provider PID: %d Process context:\n\t%s\n",
+ pid, context);
+ }
+
+ writebuf[0] = BC_TRANSACTION;
+ txn = (struct binder_transaction_data *)(&writebuf[1]);
+ memset(txn, 0, sizeof(*txn));
+ txn->target.handle = TEST_SERVICE_MANAGER_HANDLE;
+ txn->cookie = 0;
+ txn->code = ADD_TEST_SERVICE;
+ txn->flags = TF_ACCEPT_FDS;
+
+ memset(&obj, 0, sizeof(struct flat_binder_object));
+ obj.hdr.type = BINDER_TYPE_BINDER;
+ obj.flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
+ obj.binder = (uintptr_t)NULL;
+ obj.cookie = 0;
+
+ txn->data_size = sizeof(struct flat_binder_object);
+ txn->data.ptr.buffer = (uintptr_t)&obj;
+ txn->data.ptr.offsets = (uintptr_t)&obj +
+ sizeof(struct flat_binder_object);
+ txn->offsets_size = sizeof(binder_size_t);
+
+ memset(&bwr, 0, sizeof(bwr));
+ bwr.write_buffer = (uintptr_t)writebuf;
+ bwr.write_size = sizeof(writebuf[0]) + sizeof(*txn);
+
+ if (verbose)
+ printf("Service Provider sending transaction to Manager - ADD_TEST_SERVICE\n");
+
+ /* Each test will expect a different number of replies */
+ while (provider_replies) {
+ bwr.read_size = sizeof(readbuf);
+ bwr.read_consumed = 0;
+ bwr.read_buffer = (uintptr_t)readbuf;
+
+ result = ioctl(binder_fd, BINDER_WRITE_READ, &bwr);
+ if (result < 0) {
+ fprintf(stderr,
+ "Service Provider ioctl BINDER_WRITE_READ: %s\n",
+ strerror(errno));
+ result = 7;
+ goto brexit;
+ }
+
+ if (verbose)
+ printf("Service Provider read_consumed: %lld\n",
+ bwr.read_consumed);
+
+ cmd = binder_parse(binder_fd, (uintptr_t)readbuf,
+ bwr.read_consumed, manager);
+
+ if (cmd == BR_FAILED_REPLY ||
+ cmd == BR_DEAD_REPLY ||
+ cmd == BR_DEAD_BINDER) {
+ result = 8;
+ goto brexit;
+ }
+ provider_replies--;
+ }
+ }
+
+brexit:
+ free(context);
+ munmap(shm_base, shm_size);
+ close(shm_fd);
+ munmap(map_base, map_size);
+ close(binder_fd);
+
+ return result;
+}
--
2.17.0
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