create tmpdir in /dev

HuskyDG · Jun 13, 2023 · 5108725 · 5108725
1 parent 7c100a3
commit 5108725
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Showing 4 changed files with 21 additions and 25 deletions.
diff --git a/magisk-module/post-fs-data.sh b/magisk-module/post-fs-data.sh
@@ -7,12 +7,8 @@ export MAGISKTMP="$(magisk --path)"
 chmod 777 "$MODDIR/overlayfs_system"
 
 OVERLAYDIR="/data/adb/overlay"
-OVERLAYMNT="/mnt/overlay"
-MODULEMNT="/mnt/loop"
-
-if [ ! -e "/mnt/vendor/system" ]; then
-    OVERLAYMNT="/mnt/vendor/system"
-fi
+OVERLAYMNT="/dev/mount_overlayfs"
+MODULEMNT="/dev/mount_loop"
 
 
 mv -fT /cache/overlayfs.log /cache/overlayfs.log.bak

diff --git a/native/jni/main.cpp b/native/jni/main.cpp
@@ -15,7 +15,7 @@ using namespace std;
     rmdir(overlay_tmpdir.data());
 
 int log_fd = -1;
-std::string overlay_tmpdir;
+std::string overlay_tmpdir = "";
 std::vector<mount_info> mountinfo;
 
 static void collect_mounts() {
@@ -184,11 +184,11 @@ int main(int argc, const char **argv) {
     // list of directories should be mounted!
     std::vector<string> mount_list;
 
-    overlay_tmpdir = std::string("/mnt/") + "overlayfs_" + random_strc(20);
-    if (mkdirs(overlay_tmpdir.data(), 750) != 0) {
-        LOGE("Cannot create temp folder, please make sure /mnt is clean and write-able!\n");
-        return -1;
-    }
+    do {
+		char *random_string = random_strc(20);
+		overlay_tmpdir = std::string("/dev/.") + "worker_" + random_string;
+		free(random_string);
+    } while (mkdirs(overlay_tmpdir.data(), 750) != 0);
     mkdir(std::string(std::string(argv[1]) + "/upper").data(), 0750);
     mkdir(std::string(std::string(argv[1]) + "/worker").data(), 0750);
 

diff --git a/native/jni/utils.cpp b/native/jni/utils.cpp
@@ -1,22 +1,22 @@
 #include "logging.hpp"
 #include "base.hpp"
 
-std::string random_strc(int n){
-    std::string result = "";
-    FILE *urandom = fopen("/dev/urandom", "re");
-    if (urandom == nullptr) return result;
-    char *str = new char[n+1];
+char *random_strc(int n){
+    int urandom_fd = open("/dev/urandom", O_RDONLY);
+    if (urandom_fd == -1) return nullptr;
+    char *str = (char*)malloc(sizeof(char)*(n+1));
     if (str == nullptr) {
-        fclose(urandom);
-        return result;
+        close(urandom_fd);
+        return nullptr;
     }
     for (int i=0;i<n;i++){
-        str[i] = 'a' + (fgetc(urandom) % ('z'-'a'+1));
+        char x = 0;
+        read(urandom_fd, &x, 1);
+        str[i] = 'a' + (x % ('z'-'a'+1));
     }
-    fclose(urandom);
-    result = str;
-    delete []str;
-    return result;
+    str[n] = '\0';
+    close(urandom_fd);
+    return str;
 }
 
 

diff --git a/native/jni/utils.hpp b/native/jni/utils.hpp
@@ -1,6 +1,6 @@
 #include "base.hpp"
 
-std::string random_strc(int n);
+char *random_strc(int n);
 bool starts_with(const char *s, const char *ss);
 bool is_dir(const char *path);
 bool is_lnk(const char *path);