init: use read_file and write_file to implement do_copy builtin
this will make the implementation more cleaner,
and has error message output when failed on some operations
also add the O_TRUNC flag explicitly for the open function
called in write_file.
And add more test on read_file and write_file functions
Bug: 36726045
Test: manual with hikey
Test: boot and init tests on bullhead
Test: cast with fugu, per b/36726045
Merged-In: If3c30a2fff58cfece2fcd27e69c30382146e6808
Change-Id: If3c30a2fff58cfece2fcd27e69c30382146e6808
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
diff --git a/init/README.md b/init/README.md
index 822d81e..fc50730 100644
--- a/init/README.md
+++ b/init/README.md
@@ -293,6 +293,11 @@
`copy <src> <dst>`
> Copies a file. Similar to write, but useful for binary/large
amounts of data.
+ Regarding to the src file, copying from symbolic link file and world-writable
+ or group-writable files are not allowed.
+ Regarding to the dst file, the default mode created is 0600 if it does not
+ exist. And it will be truncated if dst file is a normal regular file and
+ already exists.
`domainname <name>`
> Set the domain name.
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 4ad36e0..64c00e9 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -700,61 +700,11 @@
}
static int do_copy(const std::vector<std::string>& args) {
- char *buffer = NULL;
- int rc = 0;
- int fd1 = -1, fd2 = -1;
- struct stat info;
- int brtw, brtr;
- char *p;
-
- if (stat(args[1].c_str(), &info) < 0)
- return -1;
-
- if ((fd1 = open(args[1].c_str(), O_RDONLY|O_CLOEXEC)) < 0)
- goto out_err;
-
- if ((fd2 = open(args[2].c_str(), O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0660)) < 0)
- goto out_err;
-
- if (!(buffer = (char*) malloc(info.st_size)))
- goto out_err;
-
- p = buffer;
- brtr = info.st_size;
- while(brtr) {
- rc = read(fd1, p, brtr);
- if (rc < 0)
- goto out_err;
- if (rc == 0)
- break;
- p += rc;
- brtr -= rc;
+ std::string data;
+ if (read_file(args[1], &data)) {
+ return write_file(args[2], data) ? 0 : 1;
}
-
- p = buffer;
- brtw = info.st_size;
- while(brtw) {
- rc = write(fd2, p, brtw);
- if (rc < 0)
- goto out_err;
- if (rc == 0)
- break;
- p += rc;
- brtw -= rc;
- }
-
- rc = 0;
- goto out;
-out_err:
- rc = -1;
-out:
- if (buffer)
- free(buffer);
- if (fd1 >= 0)
- close(fd1);
- if (fd2 >= 0)
- close(fd2);
- return rc;
+ return 1;
}
static int do_chown(const std::vector<std::string>& args) {
diff --git a/init/util.cpp b/init/util.cpp
index d1e0b85..bf4109c 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -188,8 +188,8 @@
}
bool write_file(const std::string& path, const std::string& content) {
- android::base::unique_fd fd(
- TEMP_FAILURE_RETRY(open(path.c_str(), O_WRONLY | O_CREAT | O_NOFOLLOW | O_CLOEXEC, 0600)));
+ android::base::unique_fd fd(TEMP_FAILURE_RETRY(
+ open(path.c_str(), O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, 0600)));
if (fd == -1) {
PLOG(ERROR) << "write_file: Unable to open '" << path << "'";
return false;
diff --git a/init/util_test.cpp b/init/util_test.cpp
index 6134998..0c0350a 100644
--- a/init/util_test.cpp
+++ b/init/util_test.cpp
@@ -17,7 +17,10 @@
#include "util.h"
#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <android-base/stringprintf.h>
#include <android-base/test_utils.h>
#include <gtest/gtest.h>
@@ -29,6 +32,35 @@
EXPECT_EQ("", s); // s was cleared.
}
+TEST(util, read_file_group_writeable) {
+ std::string s("hello");
+ TemporaryFile tf;
+ ASSERT_TRUE(tf.fd != -1);
+ EXPECT_TRUE(write_file(tf.path, s)) << strerror(errno);
+ EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0620, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
+ EXPECT_FALSE(read_file(tf.path, &s)) << strerror(errno);
+ EXPECT_EQ("", s); // s was cleared.
+}
+
+TEST(util, read_file_world_writeable) {
+ std::string s("hello");
+ TemporaryFile tf;
+ ASSERT_TRUE(tf.fd != -1);
+ EXPECT_TRUE(write_file(tf.path, s.c_str())) << strerror(errno);
+ EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0602, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
+ EXPECT_FALSE(read_file(tf.path, &s)) << strerror(errno);
+ EXPECT_EQ("", s); // s was cleared.
+}
+
+TEST(util, read_file_symbolic_link) {
+ 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));
+ 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));
@@ -55,6 +87,34 @@
EXPECT_EQ(10u, read_back_contents.size());
}
+TEST(util, write_file_not_exist) {
+ 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));
+ EXPECT_EQ(s, s2);
+ struct stat sb;
+ int fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+ EXPECT_NE(-1, fd);
+ EXPECT_EQ(0, fstat(fd, &sb));
+ EXPECT_EQ((const unsigned int)(S_IRUSR | S_IWUSR), sb.st_mode & 0777);
+ EXPECT_EQ(0, unlink(path.c_str()));
+}
+
+TEST(util, write_file_exist) {
+ 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));
+ EXPECT_STREQ("1hello1", s2.c_str());
+ EXPECT_TRUE(write_file(tf.path, "2ll2"));
+ EXPECT_TRUE(read_file(tf.path, &s2));
+ EXPECT_STREQ("2ll2", s2.c_str());
+}
+
TEST(util, decode_uid) {
EXPECT_EQ(0U, decode_uid("root"));
EXPECT_EQ(UINT_MAX, decode_uid("toot"));