android_system_core/init/devices_test.cpp
Tom Cherry f51657ccef ueventd: remove PlatformDeviceList
In order to create symlinks for USB and block devices, the path for
their parent platform device must be known.

Previously, ueventd would save each platform device that it encounters
to a list and query this list when creating the symlinks.  That,
however, is racy because the uevent socket does not differentiate
uevents from RegenerateUevents() and uevents sent by the kernel when
probing a device first the first time.  The below scenario is the
faulty  case:

1) Kernel probes parent platform device for a block device
2) ueventd calls RegenerateUevents() and starts processing uevents
3) Kernel probes block device and sends its uevents
4) ueventd picks up the block device uevent during its uevent processing,
   without yet regenerating the platform device uevent, causing improper
   symlinks to be created.

This change stops storing the platform devices in a list, and instead
traverses up the directory structure for each USB or block device
until it reaches a platform device, defined as one whose subsystem is
the platform bus.  This fixes the race and simplifies the ueventd
code.

Bug: 62436493
Bug: 62681642
Test: Boot bullhead
Test: Boot sailfish
Test: Init unit tests
Test: Boot hikey + hotplug/unplug sdcard
Merged-In: I21636355d8e434f30e0cba568598a6cf139e67f9
Change-Id: I21636355d8e434f30e0cba568598a6cf139e67f9
(cherry picked from commit c94ce7b130)
2017-06-20 14:26:15 -07:00

402 lines
16 KiB
C++

/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "devices.h"
#include <android-base/scopeguard.h>
#include <android-base/test_utils.h>
#include <gtest/gtest.h>
#include "util.h"
using namespace std::string_literals;
class DeviceHandlerTester {
public:
void TestGetSymlinks(const std::string& platform_device, const Uevent& uevent,
const std::vector<std::string> expected_links, bool block) {
TemporaryDir fake_sys_root;
device_handler_.sysfs_mount_point_ = fake_sys_root.path;
std::string platform_device_dir = fake_sys_root.path + platform_device;
mkdir_recursive(platform_device_dir, 0777, nullptr);
std::string platform_bus = fake_sys_root.path + "/bus/platform"s;
mkdir_recursive(platform_bus, 0777, nullptr);
symlink(platform_bus.c_str(), (platform_device_dir + "/subsystem").c_str());
mkdir_recursive(android::base::Dirname(fake_sys_root.path + uevent.path), 0777, nullptr);
std::vector<std::string> result;
if (block) {
result = device_handler_.GetBlockDeviceSymlinks(uevent);
} else {
result = device_handler_.GetCharacterDeviceSymlinks(uevent);
}
auto expected_size = expected_links.size();
ASSERT_EQ(expected_size, result.size());
if (expected_size == 0) return;
// Explicitly iterate so the results are visible if a failure occurs
for (unsigned int i = 0; i < expected_size; ++i) {
EXPECT_EQ(expected_links[i], result[i]);
}
}
private:
DeviceHandler device_handler_;
};
TEST(device_handler, get_character_device_symlinks_success) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/usb/usb_device/name/tty2-1:1.0",
.subsystem = "tty",
};
std::vector<std::string> expected_result{"/dev/usb/ttyname"};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_pdev_match) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/device/name/tty2-1:1.0", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_nothing_after_platform_device) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_usb_found) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/bad/bad/", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_roothub) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/usb/", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_usb_device) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/usb/usb_device/", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_final_slash) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/usb/usb_device/name", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_character_device_symlinks_no_final_name) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
.path = "/devices/platform/some_device_name/usb/usb_device//", .subsystem = "tty",
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, false);
}
TEST(device_handler, get_block_device_symlinks_success_platform) {
// These are actual paths from bullhead
const char* platform_device = "/devices/soc.0/f9824900.sdhci";
Uevent uevent = {
.path = "/devices/soc.0/f9824900.sdhci/mmc_host/mmc0/mmc0:0001/block/mmcblk0",
.partition_name = "",
.partition_num = -1,
};
std::vector<std::string> expected_result{"/dev/block/platform/soc.0/f9824900.sdhci/mmcblk0"};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_success_platform_with_partition) {
// These are actual paths from bullhead
const char* platform_device = "/devices/soc.0/f9824900.sdhci";
Uevent uevent = {
.path = "/devices/soc.0/f9824900.sdhci/mmc_host/mmc0/mmc0:0001/block/mmcblk0p1",
.partition_name = "modem",
.partition_num = 1,
};
std::vector<std::string> expected_result{
"/dev/block/platform/soc.0/f9824900.sdhci/by-name/modem",
"/dev/block/platform/soc.0/f9824900.sdhci/by-num/p1",
"/dev/block/platform/soc.0/f9824900.sdhci/mmcblk0p1",
};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_success_platform_with_partition_only_num) {
const char* platform_device = "/devices/soc.0/f9824900.sdhci";
Uevent uevent = {
.path = "/devices/soc.0/f9824900.sdhci/mmc_host/mmc0/mmc0:0001/block/mmcblk0p1",
.partition_name = "",
.partition_num = 1,
};
std::vector<std::string> expected_result{
"/dev/block/platform/soc.0/f9824900.sdhci/by-num/p1",
"/dev/block/platform/soc.0/f9824900.sdhci/mmcblk0p1",
};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_success_platform_with_partition_only_name) {
const char* platform_device = "/devices/soc.0/f9824900.sdhci";
Uevent uevent = {
.path = "/devices/soc.0/f9824900.sdhci/mmc_host/mmc0/mmc0:0001/block/mmcblk0p1",
.partition_name = "modem",
.partition_num = -1,
};
std::vector<std::string> expected_result{
"/dev/block/platform/soc.0/f9824900.sdhci/by-name/modem",
"/dev/block/platform/soc.0/f9824900.sdhci/mmcblk0p1",
};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_success_pci) {
const char* platform_device = "/devices/do/not/match";
Uevent uevent = {
.path = "/devices/pci0000:00/0000:00:1f.2/mmcblk0", .partition_name = "", .partition_num = -1,
};
std::vector<std::string> expected_result{"/dev/block/pci/pci0000:00/0000:00:1f.2/mmcblk0"};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_pci_bad_format) {
const char* platform_device = "/devices/do/not/match";
Uevent uevent = {
.path = "/devices/pci//mmcblk0", .partition_name = "", .partition_num = -1,
};
std::vector<std::string> expected_result{};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_success_vbd) {
const char* platform_device = "/devices/do/not/match";
Uevent uevent = {
.path = "/devices/vbd-1234/mmcblk0", .partition_name = "", .partition_num = -1,
};
std::vector<std::string> expected_result{"/dev/block/vbd/1234/mmcblk0"};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_vbd_bad_format) {
const char* platform_device = "/devices/do/not/match";
Uevent uevent = {
.path = "/devices/vbd-/mmcblk0", .partition_name = "", .partition_num = -1,
};
std::vector<std::string> expected_result{};
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, get_block_device_symlinks_no_matches) {
const char* platform_device = "/devices/soc.0/f9824900.sdhci";
Uevent uevent = {
.path = "/devices/soc.0/not_the_device/mmc_host/mmc0/mmc0:0001/block/mmcblk0p1",
.partition_name = "",
.partition_num = -1,
};
std::vector<std::string> expected_result;
DeviceHandlerTester device_handler_tester_;
device_handler_tester_.TestGetSymlinks(platform_device, uevent, expected_result, true);
}
TEST(device_handler, sanitize_null) {
SanitizePartitionName(nullptr);
}
TEST(device_handler, sanitize_empty) {
std::string empty;
SanitizePartitionName(&empty);
EXPECT_EQ(0u, empty.size());
}
TEST(device_handler, sanitize_allgood) {
std::string good =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"
"_-.";
std::string good_copy = good;
SanitizePartitionName(&good);
EXPECT_EQ(good_copy, good);
}
TEST(device_handler, sanitize_somebad) {
std::string string = "abc!@#$%^&*()";
SanitizePartitionName(&string);
EXPECT_EQ("abc__________", string);
}
TEST(device_handler, sanitize_allbad) {
std::string string = "!@#$%^&*()";
SanitizePartitionName(&string);
EXPECT_EQ("__________", string);
}
TEST(device_handler, sanitize_onebad) {
std::string string = ")";
SanitizePartitionName(&string);
EXPECT_EQ("_", string);
}
TEST(device_handler, DevPermissionsMatchNormal) {
// Basic from ueventd.rc
// /dev/null 0666 root root
Permissions permissions("/dev/null", 0666, 0, 0);
EXPECT_TRUE(permissions.Match("/dev/null"));
EXPECT_FALSE(permissions.Match("/dev/nullsuffix"));
EXPECT_FALSE(permissions.Match("/dev/nul"));
EXPECT_EQ(0666U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(0U, permissions.gid());
}
TEST(device_handler, DevPermissionsMatchPrefix) {
// Prefix from ueventd.rc
// /dev/dri/* 0666 root graphics
Permissions permissions("/dev/dri/*", 0666, 0, 1000);
EXPECT_TRUE(permissions.Match("/dev/dri/some_dri_device"));
EXPECT_TRUE(permissions.Match("/dev/dri/some_other_dri_device"));
EXPECT_TRUE(permissions.Match("/dev/dri/"));
EXPECT_FALSE(permissions.Match("/dev/dr/non_match"));
EXPECT_EQ(0666U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1000U, permissions.gid());
}
TEST(device_handler, DevPermissionsMatchWildcard) {
// Wildcard example
// /dev/device*name 0666 root graphics
Permissions permissions("/dev/device*name", 0666, 0, 1000);
EXPECT_TRUE(permissions.Match("/dev/devicename"));
EXPECT_TRUE(permissions.Match("/dev/device123name"));
EXPECT_TRUE(permissions.Match("/dev/deviceabcname"));
EXPECT_FALSE(permissions.Match("/dev/device123name/subdevice"));
EXPECT_FALSE(permissions.Match("/dev/deviceame"));
EXPECT_EQ(0666U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1000U, permissions.gid());
}
TEST(device_handler, DevPermissionsMatchWildcardPrefix) {
// Wildcard+Prefix example
// /dev/device*name* 0666 root graphics
Permissions permissions("/dev/device*name*", 0666, 0, 1000);
EXPECT_TRUE(permissions.Match("/dev/devicename"));
EXPECT_TRUE(permissions.Match("/dev/device123name"));
EXPECT_TRUE(permissions.Match("/dev/deviceabcname"));
EXPECT_TRUE(permissions.Match("/dev/device123namesomething"));
// FNM_PATHNAME doesn't match '/' with *
EXPECT_FALSE(permissions.Match("/dev/device123name/something"));
EXPECT_FALSE(permissions.Match("/dev/deviceame"));
EXPECT_EQ(0666U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1000U, permissions.gid());
}
TEST(device_handler, SysfsPermissionsMatchWithSubsystemNormal) {
// /sys/devices/virtual/input/input* enable 0660 root input
SysfsPermissions permissions("/sys/devices/virtual/input/input*", "enable", 0660, 0, 1001);
EXPECT_TRUE(permissions.MatchWithSubsystem("/sys/devices/virtual/input/input0", "input"));
EXPECT_FALSE(permissions.MatchWithSubsystem("/sys/devices/virtual/input/not_input0", "input"));
EXPECT_EQ(0660U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1001U, permissions.gid());
}
TEST(device_handler, SysfsPermissionsMatchWithSubsystemClass) {
// /sys/class/input/event* enable 0660 root input
SysfsPermissions permissions("/sys/class/input/event*", "enable", 0660, 0, 1001);
EXPECT_TRUE(permissions.MatchWithSubsystem(
"/sys/devices/soc.0/f9924000.i2c/i2c-2/2-0020/input/input0/event0", "input"));
EXPECT_FALSE(permissions.MatchWithSubsystem(
"/sys/devices/soc.0/f9924000.i2c/i2c-2/2-0020/input/input0/not_event0", "input"));
EXPECT_FALSE(permissions.MatchWithSubsystem(
"/sys/devices/soc.0/f9924000.i2c/i2c-2/2-0020/input/input0/event0", "not_input"));
EXPECT_EQ(0660U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1001U, permissions.gid());
}
TEST(device_handler, SysfsPermissionsMatchWithSubsystemBus) {
// /sys/bus/i2c/devices/i2c-* enable 0660 root input
SysfsPermissions permissions("/sys/bus/i2c/devices/i2c-*", "enable", 0660, 0, 1001);
EXPECT_TRUE(permissions.MatchWithSubsystem("/sys/devices/soc.0/f9967000.i2c/i2c-5", "i2c"));
EXPECT_FALSE(permissions.MatchWithSubsystem("/sys/devices/soc.0/f9967000.i2c/not-i2c", "i2c"));
EXPECT_FALSE(
permissions.MatchWithSubsystem("/sys/devices/soc.0/f9967000.i2c/i2c-5", "not_i2c"));
EXPECT_EQ(0660U, permissions.perm());
EXPECT_EQ(0U, permissions.uid());
EXPECT_EQ(1001U, permissions.gid());
}