init: do not log directly from read_file() and write_file()

Their callers may be able to add more context, so use an error string
to record the error.

Bug: 38038887
Test: boot bullhead
Test: Init unit tests
Change-Id: I46690d1c66e00a4b15cadc6fd0d6b50e990388c3

1 files changed, 57 insertions, 32 deletions

diff --git a/init/util_test.cpp b/init/util_test.cpp
index a24185b00..4bb8a8378 100644
--- a/init/util_test.cpp
+++ b/init/util_test.cpp
@@ -24,53 +24,67 @@
 #include <android-base/test_utils.h>
 #include <gtest/gtest.h>
 
-TEST(util, read_file_ENOENT) {
-  std::string s("hello");
-  errno = 0;
-  EXPECT_FALSE(read_file("/proc/does-not-exist", &s));
-  EXPECT_EQ(ENOENT, errno);
-  EXPECT_EQ("", s); // s was cleared.
+using namespace std::literals::string_literals;
+
+TEST(util, ReadFile_ENOENT) {
+    std::string s("hello");
+    std::string err;
+    errno = 0;
+    EXPECT_FALSE(ReadFile("/proc/does-not-exist", &s, &err));
+    EXPECT_EQ("Unable to open '/proc/does-not-exist': No such file or directory", err);
+    EXPECT_EQ(ENOENT, errno);
+    EXPECT_EQ("", s);  // s was cleared.
 }
 
-TEST(util, read_file_group_writeable) {
+TEST(util, ReadFileGroupWriteable) {
     std::string s("hello");
     TemporaryFile tf;
+    std::string err;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(write_file(tf.path, s)) << strerror(errno);
+    EXPECT_TRUE(WriteFile(tf.path, s, &err)) << strerror(errno);
+    EXPECT_EQ("", err);
     EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0620, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
-    EXPECT_FALSE(read_file(tf.path, &s)) << strerror(errno);
+    EXPECT_FALSE(ReadFile(tf.path, &s, &err)) << strerror(errno);
+    EXPECT_EQ("Skipping insecure file '"s + tf.path + "'", err);
     EXPECT_EQ("", s);  // s was cleared.
 }
 
-TEST(util, read_file_world_writeable) {
+TEST(util, ReadFileWorldWiteable) {
     std::string s("hello");
     TemporaryFile tf;
+    std::string err;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(write_file(tf.path, s.c_str())) << strerror(errno);
+    EXPECT_TRUE(WriteFile(tf.path, s, &err)) << strerror(errno);
+    EXPECT_EQ("", err);
     EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0602, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
-    EXPECT_FALSE(read_file(tf.path, &s)) << strerror(errno);
+    EXPECT_FALSE(ReadFile(tf.path, &s, &err)) << strerror(errno);
+    EXPECT_EQ("Skipping insecure file '"s + tf.path + "'", err);
     EXPECT_EQ("", s);  // s was cleared.
 }
 
-TEST(util, read_file_symbolic_link) {
+TEST(util, ReadFileSymbolicLink) {
     std::string s("hello");
     errno = 0;
     // lrwxrwxrwx 1 root root 13 1970-01-01 00:00 charger -> /sbin/healthd
-    EXPECT_FALSE(read_file("/charger", &s));
+    std::string err;
+    EXPECT_FALSE(ReadFile("/charger", &s, &err));
+    EXPECT_EQ("Unable to open '/charger': Too many symbolic links encountered", err);
     EXPECT_EQ(ELOOP, errno);
     EXPECT_EQ("", s);  // s was cleared.
 }
 
-TEST(util, read_file_success) {
-  std::string s("hello");
-  EXPECT_TRUE(read_file("/proc/version", &s));
-  EXPECT_GT(s.length(), 6U);
-  EXPECT_EQ('\n', s[s.length() - 1]);
-  s[5] = 0;
-  EXPECT_STREQ("Linux", s.c_str());
+TEST(util, ReadFileSuccess) {
+    std::string s("hello");
+    std::string err;
+    EXPECT_TRUE(ReadFile("/proc/version", &s, &err));
+    EXPECT_EQ("", err);
+    EXPECT_GT(s.length(), 6U);
+    EXPECT_EQ('\n', s[s.length() - 1]);
+    s[5] = 0;
+    EXPECT_STREQ("Linux", s.c_str());
 }
 
-TEST(util, write_file_binary) {
+TEST(util, WriteFileBinary) {
     std::string contents("abcd");
     contents.push_back('\0');
     contents.push_back('\0');
@@ -78,22 +92,28 @@ TEST(util, write_file_binary) {
     ASSERT_EQ(10u, contents.size());
 
     TemporaryFile tf;
+    std::string err;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(write_file(tf.path, contents)) << strerror(errno);
+    EXPECT_TRUE(WriteFile(tf.path, contents, &err)) << strerror(errno);
+    EXPECT_EQ("", err);
 
     std::string read_back_contents;
-    EXPECT_TRUE(read_file(tf.path, &read_back_contents)) << strerror(errno);
+    EXPECT_TRUE(ReadFile(tf.path, &read_back_contents, &err)) << strerror(errno);
+    EXPECT_EQ("", err);
     EXPECT_EQ(contents, read_back_contents);
     EXPECT_EQ(10u, read_back_contents.size());
 }
 
-TEST(util, write_file_not_exist) {
+TEST(util, WriteFileNotExist) {
     std::string s("hello");
     std::string s2("hello");
     TemporaryDir test_dir;
     std::string path = android::base::StringPrintf("%s/does-not-exist", test_dir.path);
-    EXPECT_TRUE(write_file(path, s));
-    EXPECT_TRUE(read_file(path, &s2));
+    std::string err;
+    EXPECT_TRUE(WriteFile(path, s, &err));
+    EXPECT_EQ("", err);
+    EXPECT_TRUE(ReadFile(path, &s2, &err));
+    EXPECT_EQ("", err);
     EXPECT_EQ(s, s2);
     struct stat sb;
     int fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
@@ -103,15 +123,20 @@ TEST(util, write_file_not_exist) {
     EXPECT_EQ(0, unlink(path.c_str()));
 }
 
-TEST(util, write_file_exist) {
+TEST(util, WriteFileExist) {
     std::string s2("");
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(write_file(tf.path, "1hello1")) << strerror(errno);
-    EXPECT_TRUE(read_file(tf.path, &s2));
+    std::string err;
+    EXPECT_TRUE(WriteFile(tf.path, "1hello1", &err)) << strerror(errno);
+    EXPECT_EQ("", err);
+    EXPECT_TRUE(ReadFile(tf.path, &s2, &err));
+    EXPECT_EQ("", err);
     EXPECT_STREQ("1hello1", s2.c_str());
-    EXPECT_TRUE(write_file(tf.path, "2ll2"));
-    EXPECT_TRUE(read_file(tf.path, &s2));
+    EXPECT_TRUE(WriteFile(tf.path, "2ll2", &err));
+    EXPECT_EQ("", err);
+    EXPECT_TRUE(ReadFile(tf.path, &s2, &err));
+    EXPECT_EQ("", err);
     EXPECT_STREQ("2ll2", s2.c_str());
 }