From 82bac0de6d95bcdf45729516f6a4f29eb2681118 Mon Sep 17 00:00:00 2001 From: Yongqin Liu Date: Wed, 28 Dec 2016 16:06:19 +0800 Subject: [PATCH] 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 Test: manual with hikey Change-Id: Ifc1086a20e85db6980b497b1150a8a7952e672d6 Signed-off-by: Yongqin Liu --- init/README.md | 5 ++++ init/builtins.cpp | 58 +++---------------------------------- init/util.cpp | 4 +-- init/util_test.cpp | 71 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 82 insertions(+), 56 deletions(-) diff --git a/init/README.md b/init/README.md index 99522b95e..709c6675f 100644 --- a/init/README.md +++ b/init/README.md @@ -282,6 +282,11 @@ Commands `copy ` > Copies a file. Similar to write, but useful for binary/large amounts of data. + Regarding to the src file, copying from symbol 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 ` > Set the domain name. diff --git a/init/builtins.cpp b/init/builtins.cpp index 43eb378d7..c7dffb105 100644 --- a/init/builtins.cpp +++ b/init/builtins.cpp @@ -839,61 +839,11 @@ static int do_write(const std::vector& args) { } static int do_copy(const std::vector& 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].c_str(), &data)) { + return write_file(args[2].c_str(), data.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& args) { diff --git a/init/util.cpp b/init/util.cpp index c98718101..9b02de228 100644 --- a/init/util.cpp +++ b/init/util.cpp @@ -184,8 +184,8 @@ bool read_file(const char* path, std::string* content) { } bool write_file(const char* path, const char* content) { - android::base::unique_fd fd( - TEMP_FAILURE_RETRY(open(path, O_WRONLY | O_CREAT | O_NOFOLLOW | O_CLOEXEC, 0600))); + android::base::unique_fd fd(TEMP_FAILURE_RETRY( + open(path, 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 24c75c42d..4e82e76f9 100644 --- a/init/util_test.cpp +++ b/init/util_test.cpp @@ -17,9 +17,15 @@ #include "util.h" #include +#include + +#include #include +#include +#include + TEST(util, read_file_ENOENT) { std::string s("hello"); errno = 0; @@ -28,6 +34,35 @@ TEST(util, read_file_ENOENT) { 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.c_str())) << 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_symbol_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)); @@ -37,6 +72,42 @@ TEST(util, read_file_success) { EXPECT_STREQ("Linux", s.c_str()); } +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.c_str(), s.c_str())); + EXPECT_TRUE(read_file(path.c_str(), &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_NE(0u, sb.st_mode & S_IRUSR); + EXPECT_NE(0u, sb.st_mode & S_IWUSR); + EXPECT_EQ(0u, sb.st_mode & S_IXUSR); + EXPECT_EQ(0u, sb.st_mode & S_IRGRP); + EXPECT_EQ(0u, sb.st_mode & S_IWGRP); + EXPECT_EQ(0u, sb.st_mode & S_IXGRP); + EXPECT_EQ(0u, sb.st_mode & S_IROTH); + EXPECT_EQ(0u, sb.st_mode & S_IWOTH); + EXPECT_EQ(0u, sb.st_mode & S_IXOTH); + 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, "2hello2")); + EXPECT_TRUE(read_file(tf.path, &s2)); + EXPECT_STREQ("2hello2", s2.c_str()); +} + TEST(util, decode_uid) { EXPECT_EQ(0U, decode_uid("root")); EXPECT_EQ(UINT_MAX, decode_uid("toot"));