ueventd: Write tests for the get_*_symlinks() functions

Bug: 33785894
Bug: 36250207
Test: Boot bullhead + new unit tests
Change-Id: Ia0f290542eb1cffce5ae876dfedb453dde960253
diff --git a/init/devices_test.cpp b/init/devices_test.cpp
new file mode 100644
index 0000000..f79c96d
--- /dev/null
+++ b/init/devices_test.cpp
@@ -0,0 +1,270 @@
+/*
+ * 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 <string>
+#include <vector>
+
+#include <android-base/scopeguard.h>
+#include <gtest/gtest.h>
+
+template <char** (*Function)(uevent*)>
+void test_get_symlinks(const std::string& platform_device_name, uevent* uevent,
+                       const std::vector<std::string> expected_links) {
+    add_platform_device(platform_device_name.c_str());
+    auto platform_device_remover = android::base::make_scope_guard(
+        [&platform_device_name]() { remove_platform_device(platform_device_name.c_str()); });
+
+    char** result = Function(uevent);
+    auto result_freer = android::base::make_scope_guard([result]() {
+        if (result) {
+            for (int i = 0; result[i]; i++) {
+                free(result[i]);
+            }
+            free(result);
+        }
+    });
+
+    auto expected_size = expected_links.size();
+    if (expected_size == 0) {
+        ASSERT_EQ(nullptr, result);
+    } else {
+        ASSERT_NE(nullptr, result);
+        // First assert size is equal, so we don't overrun expected_links
+        unsigned int size = 0;
+        while (result[size]) ++size;
+        ASSERT_EQ(expected_size, size);
+
+        for (unsigned int i = 0; i < size; ++i) {
+            EXPECT_EQ(expected_links[i], result[i]);
+        }
+    }
+}
+
+TEST(devices, 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"};
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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;
+
+    test_get_symlinks<get_character_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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 = nullptr,
+        .partition_num = -1,
+    };
+    std::vector<std::string> expected_result{"/dev/block/platform/soc.0/f9824900.sdhci/mmcblk0"};
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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",
+    };
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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 = nullptr,
+        .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",
+    };
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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",
+    };
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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 = nullptr,
+        .partition_num = -1,
+    };
+    std::vector<std::string> expected_result{"/dev/block/pci/pci0000:00/0000:00:1f.2/mmcblk0"};
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, get_block_device_symlinks_success_vbd) {
+    const char* platform_device = "/devices/do/not/match";
+    uevent uevent = {
+        .path = "/devices/vbd-1234/mmcblk0", .partition_name = nullptr, .partition_num = -1,
+    };
+    std::vector<std::string> expected_result{"/dev/block/vbd/1234/mmcblk0"};
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, 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 = nullptr,
+        .partition_num = -1,
+    };
+    std::vector<std::string> expected_result;
+
+    test_get_symlinks<get_block_device_symlinks>(platform_device, &uevent, expected_result);
+}
+
+TEST(devices, sanitize_null) {
+    sanitize_partition_name(nullptr);
+}
+
+TEST(devices, sanitize_empty) {
+    std::string empty;
+    sanitize_partition_name(&empty[0]);
+    EXPECT_EQ(0u, empty.size());
+}
+
+TEST(devices, sanitize_allgood) {
+    std::string good =
+        "abcdefghijklmnopqrstuvwxyz"
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "0123456789"
+        "_-.";
+    std::string good_copy = good;
+    sanitize_partition_name(&good[0]);
+    EXPECT_EQ(good_copy, good);
+}
+
+TEST(devices, sanitize_somebad) {
+    std::string string = "abc!@#$%^&*()";
+    sanitize_partition_name(&string[0]);
+    EXPECT_EQ("abc__________", string);
+}
+
+TEST(devices, sanitize_allbad) {
+    std::string string = "!@#$%^&*()";
+    sanitize_partition_name(&string[0]);
+    EXPECT_EQ("__________", string);
+}
+
+TEST(devices, sanitize_onebad) {
+    std::string string = ")";
+    sanitize_partition_name(&string[0]);
+    EXPECT_EQ("_", string);
+}