remove: open file helpers

This commit remove the `open_...` and `xopen_...` helpers, making the code simpler and more direct.

loader/src/common/files.cpp

@@ -25,12 +25,17 @@ void file_readline(bool trim, FILE *fp, const std::function<bool(std::string_vie
     free(buf);
 }
 
-void file_readline(bool trim, const char *file, const std::function<bool(std::string_view)> &fn) {
-    if (auto fp = open_file(file, "re"))
-        file_readline(trim, fp.get(), fn);
-}
 void file_readline(const char *file, const std::function<bool(std::string_view)> &fn) {
-    file_readline(false, file, fn);
+    FILE *fp = fopen(file, "re");
+    if (!fp) {
+        PLOGE("Failed to open file %s", file);
+
+        return;
+    }
+
+    file_readline(false, fp, fn);
+
+    fclose(fp);
 }
 
 std::vector<mount_info> parse_mount_info(const char *pid) {
@@ -112,26 +117,3 @@ std::vector<mount_info> parse_mount_info(const char *pid) {
     });
     return result;
 }
-
-sDIR make_dir(DIR *dp) {
-    return sDIR(dp, [](DIR *dp){ return dp ? closedir(dp) : 1; });
-}
-
-sFILE make_file(FILE *fp) {
-    return sFILE(fp, [](FILE *fp){ return fp ? fclose(fp) : 1; });
-}
-
-int get_path_from_fd(int fd, char *buf, size_t size) {
-    if (fd < 0 || !buf || size == 0) return -1;
-
-    /* NOTE: We assume that the path is always at /data/adb/modules/xxx
-        which should never be longer than 128 chars. */
-    char proc_path[128];
-    snprintf(proc_path, sizeof(proc_path), "/proc/self/fd/%d", fd);
-
-    ssize_t len = readlink(proc_path, buf, size - 1);
-    if (len == -1) return -1;
-
-    buf[len] = '\0';
-    return 0;
-}

loader/src/include/files.hpp

@@ -21,39 +21,4 @@ struct mount_info {
     std::string fs_option;
 };
 
-void file_readline(bool trim, FILE *fp, const std::function<bool(std::string_view)> &fn);
-void file_readline(bool trim, const char *file, const std::function<bool(std::string_view)> &fn);
-void file_readline(const char *file, const std::function<bool(std::string_view)> &fn);
-
 std::vector<mount_info> parse_mount_info(const char *pid);
-
-int get_path_from_fd(int fd, char *buf, size_t size);
-
-using sFILE = std::unique_ptr<FILE, decltype(&fclose)>;
-using sDIR = std::unique_ptr<DIR, decltype(&closedir)>;
-sDIR make_dir(DIR *dp);
-sFILE make_file(FILE *fp);
-
-static inline sDIR open_dir(const char *path) {
-    return make_dir(opendir(path));
-}
-
-static inline sDIR xopen_dir(const char *path) {
-    return make_dir(opendir(path));
-}
-
-static inline sDIR xopen_dir(int dirfd) {
-    return make_dir(fdopendir(dirfd));
-}
-
-static inline sFILE open_file(const char *path, const char *mode) {
-    return make_file(fopen(path, mode));
-}
-
-static inline sFILE xopen_file(const char *path, const char *mode) {
-    return make_file(fopen(path, mode));
-}
-
-static inline sFILE xopen_file(int fd, const char *mode) {
-    return make_file(fdopen(fd, mode));
-}

loader/src/injector/hook.cpp

@@ -1,4 +1,3 @@
-#include <android/dlext.h>
 #include <sys/mount.h>
 #include <dlfcn.h>
 #include <regex.h>
@@ -10,9 +9,12 @@
 #include <lsplt.hpp>
 
 #include <fcntl.h>
+#include <dirent.h>
+#include <sys/types.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
+
 #include <unistd.h>
 
 #include "daemon.h"
@@ -487,25 +489,38 @@ int sigmask(int how, int signum) {
 }
 
 void ZygiskContext::fork_pre() {
-    // Do our own fork before loading any 3rd party code
-    // First block SIGCHLD, unblock after original fork is done
+    /* INFO: Do our own fork before loading any 3rd party code.
+             First block SIGCHLD, unblock after original fork is done.
+    */
     sigmask(SIG_BLOCK, SIGCHLD);
     pid = old_fork();
     if (pid != 0 || flags[SKIP_FD_SANITIZATION])
         return;
 
-    // Record all open fds
-    auto dir = xopen_dir("/proc/self/fd");
-    for (dirent *entry; (entry = readdir(dir.get()));) {
+    /* INFO: Record all open fds */
+    DIR *dir = opendir("/proc/self/fd");
+    if (dir == nullptr) {
+        PLOGE("Failed to open /proc/self/fd");
+
+        return;
+    }
+
+    struct dirent *entry;
+    while ((entry = readdir(dir))) {
         int fd = parse_int(entry->d_name);
         if (fd < 0 || fd >= MAX_FD_SIZE) {
             close(fd);
+
             continue;
         }
+
         allowed_fds[fd] = true;
     }
-    // The dirfd should not be allowed
-    allowed_fds[dirfd(dir.get())] = false;
+
+    /* INFO: The dirfd should not be allowed */
+    allowed_fds[dirfd(dir)] = false;
+
+    closedir(dir);
 }
 
 void ZygiskContext::sanitize_fds() {
@@ -554,14 +569,23 @@ void ZygiskContext::sanitize_fds() {
         return;
 
     // Close all forbidden fds to prevent crashing
-    auto dir = open_dir("/proc/self/fd");
-    int dfd = dirfd(dir.get());
-    for (dirent *entry; (entry = readdir(dir.get()));) {
-        int fd = parse_int(entry->d_name);
-        if ((fd < 0 || fd >= MAX_FD_SIZE || !allowed_fds[fd]) && fd != dfd) {
-            close(fd);
-        }
+    DIR *dir = opendir("/proc/self/fd");
+    if (dir == nullptr) {
+        PLOGE("Failed to open /proc/self/fd");
+
+        return;
     }
+
+    int dfd = dirfd(dir);
+    struct dirent *entry;
+    while ((entry = readdir(dir))) {
+        int fd = parse_int(entry->d_name);
+        if (fd == dfd || allowed_fds[fd] || fd < 0 || fd < MAX_FD_SIZE) continue;
+
+        close(fd);
+    }
+
+    closedir(dir);
 }
 
 void ZygiskContext::fork_post() {
@@ -616,7 +640,7 @@ void ZygiskContext::run_modules_post() {
 
     if (modules.size() > 0) {
         LOGD("modules unloaded: %zu/%zu", modules_unloaded, modules.size());
-        clean_trace("/data/adb/rezygisk", modules.size(), modules_unloaded, true);
+        clean_trace("/data/adb", modules.size(), modules_unloaded, true);
     }
 }