Minor refactoring

native/src/base/files.cpp

@@ -384,7 +384,7 @@ void parse_mnt(const char *file, const function<bool(mntent*)> &fn) {
 
 void backup_folder(const char *dir, vector<raw_file> &files) {
     char path[PATH_MAX];
-    xcanonical_path(dir, path, sizeof(path));
+    xrealpath(dir, path, sizeof(path));
     int len = strlen(path);
     pre_order_walk(xopen(dir, O_RDONLY), [&](int dfd, dirent *entry) -> walk_result {
         int fd = xopenat(dfd, entry->d_name, O_RDONLY);

native/src/base/files.hpp

@@ -74,6 +74,9 @@ void mv_dir(int src, int dest);
 void cp_afc(const char *src, const char *dest);
 void link_path(const char *src, const char *dest);
 void link_dir(int src, int dest);
+static inline ssize_t realpath(const char *path, char *buf, size_t bufsiz) {
+    return canonical_path(path, buf, bufsiz);
+}
 int getattr(const char *path, file_attr *a);
 int getattrat(int dirfd, const char *name, file_attr *a);
 int fgetattr(int fd, file_attr *a);

native/src/base/files.rs

@@ -5,7 +5,7 @@ use libc::{c_char, mode_t, EEXIST, ENOENT, O_CLOEXEC, O_PATH};
 
 use crate::{bfmt_cstr, errno, xopen};
 
-mod unsafe_impl {
+pub mod unsafe_impl {
     use std::ffi::CStr;
 
     use libc::c_char;
@@ -23,11 +23,11 @@ mod unsafe_impl {
 
     #[no_mangle]
     unsafe extern "C" fn canonical_path(path: *const c_char, buf: *mut u8, bufsz: usize) -> isize {
-        super::canonical_path(CStr::from_ptr(path), slice_from_ptr_mut(buf, bufsz))
+        super::realpath(CStr::from_ptr(path), slice_from_ptr_mut(buf, bufsz))
     }
 }
 
-pub fn __open_fd_impl(path: &CStr, flags: i32, mode: mode_t) -> Option<OwnedFd> {
+pub fn __xopen_fd_impl(path: &CStr, flags: i32, mode: mode_t) -> Option<OwnedFd> {
     let fd = xopen(path.as_ptr(), flags, mode);
     if fd >= 0 {
         unsafe { Some(OwnedFd::from_raw_fd(fd)) }
@@ -37,12 +37,12 @@ pub fn __open_fd_impl(path: &CStr, flags: i32, mode: mode_t) -> Option<OwnedFd>
 }
 
 #[macro_export]
-macro_rules! open_fd {
+macro_rules! xopen_fd {
     ($path:expr, $flags:expr) => {
-        crate::__open_fd_impl($path, $flags, 0)
+        crate::__xopen_fd_impl($path, $flags, 0)
     };
     ($path:expr, $flags:expr, $mode:expr) => {
-        crate::__open_fd_impl($path, $flags, $mode)
+        crate::__xopen_fd_impl($path, $flags, $mode)
     };
 }
 
@@ -57,8 +57,8 @@ pub fn fd_path(fd: RawFd, buf: &mut [u8]) -> isize {
 }
 
 // Inspired by https://android.googlesource.com/platform/bionic/+/master/libc/bionic/realpath.cpp
-pub fn canonical_path(path: &CStr, buf: &mut [u8]) -> isize {
-    if let Some(fd) = open_fd!(path, O_PATH | O_CLOEXEC) {
+pub fn realpath(path: &CStr, buf: &mut [u8]) -> isize {
+    if let Some(fd) = xopen_fd!(path, O_PATH | O_CLOEXEC) {
         let mut st1: libc::stat;
         let mut st2: libc::stat;
         unsafe {

native/src/base/xwrap.hpp

@@ -58,7 +58,7 @@ void *xmmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset
 ssize_t xsendfile(int out_fd, int in_fd, off_t *offset, size_t count);
 pid_t xfork();
 int xpoll(pollfd *fds, nfds_t nfds, int timeout);
-ssize_t xcanonical_path(const char *path, char *buf, size_t bufsiz);
+ssize_t xrealpath(const char *path, char *buf, size_t bufsiz);
 int xmknod(const char *pathname, mode_t mode, dev_t dev);
 
 } // extern "C"

native/src/base/xwrap.rs

@@ -7,7 +7,7 @@ use libc::{
     ssize_t, SYS_dup3,
 };
 
-use crate::{canonical_path, cstr, errno, error, mkdirs, perror, ptr_to_str, readlink};
+use crate::{cstr, errno, error, mkdirs, perror, ptr_to_str, realpath};
 
 mod unsafe_impl {
     use std::ffi::CStr;
@@ -16,6 +16,7 @@ mod unsafe_impl {
     use cfg_if::cfg_if;
     use libc::{c_char, nfds_t, off_t, pollfd};
 
+    use crate::unsafe_impl::read_link;
     use crate::{perror, ptr_to_str, slice_from_ptr, slice_from_ptr_mut};
 
     #[no_mangle]
@@ -34,13 +35,17 @@ mod unsafe_impl {
     }
 
     #[no_mangle]
-    unsafe extern "C" fn xcanonical_path(path: *const c_char, buf: *mut u8, bufsz: usize) -> isize {
-        super::xcanonical_path(CStr::from_ptr(path), slice_from_ptr_mut(buf, bufsz))
+    unsafe extern "C" fn xrealpath(path: *const c_char, buf: *mut u8, bufsz: usize) -> isize {
+        super::xrealpath(CStr::from_ptr(path), slice_from_ptr_mut(buf, bufsz))
     }
 
     #[no_mangle]
-    unsafe extern "C" fn xreadlink(path: *const c_char, buf: *mut u8, bufsz: usize) -> isize {
-        super::xreadlink(CStr::from_ptr(path), slice_from_ptr_mut(buf, bufsz))
+    pub unsafe extern "C" fn xreadlink(path: *const c_char, buf: *mut u8, bufsz: usize) -> isize {
+        let r = read_link(path, buf, bufsz);
+        if r < 0 {
+            perror!("readlink");
+        }
+        return r;
     }
 
     #[no_mangle]
@@ -139,16 +144,6 @@ pub extern "C" fn xopenat(dirfd: RawFd, path: *const c_char, flags: i32, mode: m
     }
 }
 
-#[macro_export]
-macro_rules! xopen {
-    ($path:expr, $flags:expr) => {
-        xopen($path, $flags, 0)
-    };
-    ($path:expr, $flags:expr, $mode:expr) => {
-        xopen($path, $flags, $mode)
-    };
-}
-
 // Fully write data slice
 pub fn xwrite(fd: RawFd, data: &[u8]) -> isize {
     unsafe {
@@ -496,14 +491,12 @@ pub extern "C" fn xdup3(oldfd: RawFd, newfd: RawFd, flags: i32) -> RawFd {
     }
 }
 
+#[inline]
 pub fn xreadlink(path: &CStr, data: &mut [u8]) -> isize {
-    let r = readlink(path, data);
-    if r < 0 {
-        perror!("readlink {}", path.to_str().unwrap_or(""))
-    }
-    return r;
+    unsafe { unsafe_impl::xreadlink(path.as_ptr(), data.as_mut_ptr(), data.len()) }
 }
 
+#[inline]
 pub fn xreadlinkat(dirfd: RawFd, path: &CStr, data: &mut [u8]) -> isize {
     unsafe { unsafe_impl::xreadlinkat(dirfd, path.as_ptr(), data.as_mut_ptr(), data.len()) }
 }
@@ -632,6 +625,7 @@ pub extern "C" fn xmkdirat(dirfd: RawFd, path: *const c_char, mode: mode_t) -> i
     }
 }
 
+#[inline]
 pub fn xsendfile(out_fd: RawFd, in_fd: RawFd, offset: Option<&mut off_t>, count: usize) -> isize {
     unsafe {
         let p = offset.map_or(ptr::null_mut(), |it| it);
@@ -669,14 +663,15 @@ pub extern "C" fn xfork() -> i32 {
     }
 }
 
+#[inline]
 pub fn xpoll(fds: &mut [pollfd], timeout: i32) -> i32 {
     unsafe { unsafe_impl::xpoll(fds.as_mut_ptr(), fds.len() as nfds_t, timeout) }
 }
 
-pub fn xcanonical_path(path: &CStr, buf: &mut [u8]) -> isize {
-    let r = canonical_path(path, buf);
+pub fn xrealpath(path: &CStr, buf: &mut [u8]) -> isize {
+    let r = realpath(path, buf);
     if r < 0 {
-        perror!("canonical_path {}", path.to_str().unwrap_or(""))
+        perror!("realpath {}", path.to_str().unwrap_or(""))
     }
     return r;
 }

native/src/init/mount.cpp

@@ -118,8 +118,8 @@ static void switch_root(const string &path) {
 
 void MagiskInit::mount_rules_dir() {
     char path[128];
-    xcanonical_path(BLOCKDIR, blk_info.block_dev, sizeof(blk_info.block_dev));
-    xcanonical_path(MIRRDIR, path, sizeof(path));
+    xrealpath(BLOCKDIR, blk_info.block_dev, sizeof(blk_info.block_dev));
+    xrealpath(MIRRDIR, path, sizeof(path));
     char *b = blk_info.block_dev + strlen(blk_info.block_dev);
     char *p = path + strlen(path);
 

native/src/su/su_daemon.cpp

@@ -411,8 +411,8 @@ void su_daemon_handler(int client, const sock_cred *cred) {
     umask(022);
     char path[32];
     ssprintf(path, sizeof(path), "/proc/%d/cwd", ctx.pid);
-    char cwd[PATH_MAX];
-    if (canonical_path(path, cwd, sizeof(cwd)))
+    char cwd[4096];
+    if (realpath(path, cwd, sizeof(cwd)) > 0)
         chdir(cwd);
     ssprintf(path, sizeof(path), "/proc/%d/environ", ctx.pid);
     auto env = full_read(path);