Add support for FileDispatcherImpl/UnixNativeDispatcher

CMakeLists.txt

@@ -14,7 +14,7 @@ add_custom_target(build_info ALL
 
 find_package(JNI REQUIRED)
 
-add_library(substagent SHARED src/substagent.c src/fis_hook.c src/utils.c)
+add_library(substagent SHARED src/substagent.c src/fis_hook.c src/fdi_hook.c src/utils.c)
 add_library(stb INTERFACE)
 
 target_include_directories(stb INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/external/stb)

src/fdi_hook.c

@@ -0,0 +1,80 @@
+#include "fdi_hook.h"
+#include "stb_ds.h"
+#include "utils.h"
+#include <stdint.h>
+#include <string.h>
+
+und_open0_t und_real_open0 = NULL;
+
+fdi_read0_t fdi_real_read0 = NULL;
+
+struct file {
+    jint key;
+    struct file_data value;
+} *fdi_files_map = NULL;
+
+jint JNICALL und_open0_hook(JNIEnv *env, jobject thiz, jlong path_address, jint flags, jint mode) {
+    jint fd = und_real_open0(env, thiz, path_address, flags, mode);
+    const char *path = (const char *)(intptr_t)path_address;
+    if (!path || !is_config_path(path)) {
+        return fd;
+    }
+
+    FILE *file = fopen(path, "rb");
+    if (!file) {
+        jclass fileNotFoundException =
+                (*env)->FindClass(env, "java/io/FileNotFoundException");
+        (*env)->ThrowNew(env, fileNotFoundException, path);
+        return fd;
+    }
+    fseek(file, 0, SEEK_END);
+    size_t fsize = ftell(file);
+    if (fsize == 0) {
+        return fd;
+    }
+    fseek(file, 0, SEEK_SET);
+
+    char *data = malloc(fsize + 1);
+    fread(data, fsize, 1, file);
+    data[fsize] = '\0';
+
+    parse_file(&data, fsize);
+
+    size_t fd_len = strlen(data);
+
+    struct file_data file_data;
+    file_data.data = data;
+    file_data.length = fd_len;
+    file_data.index = 0;
+    file_data.freed = 0;
+    hmput(fdi_files_map, fd, file_data);
+
+    return fd;
+}
+
+jint JNICALL fdi_read0_hook(JNIEnv *env, jobject thiz, jobject fdObject, jlong address, jint len) {
+    jclass class = (*env)->GetObjectClass(env, fdObject);
+    jfieldID fieldID = (*env)->GetFieldID(env, class, "fd", "I");
+    jint fd = (*env)->GetIntField(env, fdObject, fieldID);
+
+    struct file *file = hmgetp(fdi_files_map, fd);
+    if (file->key != fd) {
+        return fdi_real_read0(env, thiz, fdObject, address, len);
+    } else if (file->value.freed) {
+        return -1;
+    }
+
+    struct file_data *file_data = &file->value;
+
+    int n = MIN(len, file_data->length - file_data->index);
+    memcpy((void *)(intptr_t)address, file_data->data + file_data->index, n);
+
+    if (n == file_data->length - file_data->index) {
+        free(file_data->data);
+        file_data->freed = 1;
+    } else {
+        file_data->index += n;
+    }
+
+    return n;
+}

src/fdi_hook.h

@@ -0,0 +1,17 @@
+#ifndef FDI_HOOK_H
+#define FDI_HOOK_H
+
+#include <jvmti.h>
+#include <jni.h>
+
+typedef jint (JNICALL *und_open0_t)(JNIEnv*, jobject, jlong, jint, jint);
+extern und_open0_t und_real_open0;
+
+typedef jint (JNICALL *fdi_read0_t)(JNIEnv*, jobject, jobject, jlong, jint);
+extern fdi_read0_t fdi_real_read0;
+
+jint JNICALL und_open0_hook(JNIEnv*, jobject, jlong, jint, jint);
+
+jint JNICALL fdi_read0_hook(JNIEnv*, jobject, jobject, jlong, jint);
+
+#endif

src/fis_hook.c

@@ -3,19 +3,19 @@
 #define STB_DS_IMPLEMENTATION
 #include "stb_ds.h"
 
-readBytes_t fis_real_readBytes = NULL;
-open0_t fis_real_open0 = NULL;
-read0_t fis_real_read0 = NULL;
-length0_t fis_real_length0 = NULL;
-position0_t fis_real_position0 = NULL;
-skip0_t fis_real_skip0 = NULL;
-available0_t fis_real_available0 = NULL;
-close_t fis_real_close = NULL;
+fis_readBytes_t fis_real_readBytes = NULL;
+fis_open0_t fis_real_open0 = NULL;
+fis_read0_t fis_real_read0 = NULL;
+fis_length0_t fis_real_length0 = NULL;
+fis_position0_t fis_real_position0 = NULL;
+fis_skip0_t fis_real_skip0 = NULL;
+fis_available0_t fis_real_available0 = NULL;
+fis_close_t fis_real_close = NULL;
 
 struct file{
     jint key;
     struct file_data value;
-} *files_map = NULL;
+} *fis_files_map = NULL;
 
 jint JNICALL fis_readBytes_hook(JNIEnv* env, jobject thiz, jbyteArray buf, jint off, jint len) {
     if (!has_tag(thiz)) {
@@ -27,7 +27,7 @@ jint JNICALL fis_readBytes_hook(JNIEnv* env, jobject thiz, jbyteArray buf, jint
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash || file->value.freed) {
         return -1;
     }
@@ -86,66 +86,20 @@ void JNICALL fis_open0_hook(JNIEnv* env, jobject thiz, jstring jpath) {
     }
     fseek(file, 0, SEEK_SET);
 
-    char *file_data = malloc(fsize + 1);
-    fread(file_data, fsize, 1, file);
-    file_data[fsize] = '\0';
+    char *data = malloc(fsize + 1);
+    fread(data, fsize, 1, file);
+    data[fsize] = '\0';
 
-    int dollar_sign_matched_index = -1;
-    char env_var[4096];
-    env_var[0] = '\0';
-    for (size_t i = 0; i < fsize; i++) {
-        char c = file_data[i];
-        if (dollar_sign_matched_index != -1) {
-            if ((c >= 48 && c <= 57) || (c >= 65 && c <= 90) || (c >= 97 && c <= 122) || c == 95) {
-                size_t len = strlen(env_var);
-                env_var[len] = c;
-                env_var[len + 1] = '\0';
-            } else {
-                if (strlen(env_var) == 0) continue;
-                char* value = getenv(env_var);
-                if (!value) {
-                    dollar_sign_matched_index = -1;
-                    env_var[0] = '\0';
-                    continue;
-                }
+    parse_file(&data, fsize);
 
-                size_t env_len = i - dollar_sign_matched_index;
+    size_t fd_len = strlen(data);
 
-                char* new_data = substitute(value, dollar_sign_matched_index, i, env_len, file_data);
-                free(file_data);
-                file_data = new_data;
-
-                dollar_sign_matched_index = -1;
-                env_var[0] = '\0';
-                continue;
-            }
-        } else {
-            if (c == '$') {
-                dollar_sign_matched_index = i;
-            }
-        }
-    }
-    if (dollar_sign_matched_index != -1) {
-        if (strlen(env_var) != 0) {
-            char* value = getenv(env_var);
-            if (value) {
-                size_t env_len = fsize - dollar_sign_matched_index;
-
-                char* new_data = substitute(value, dollar_sign_matched_index, fsize, env_len, file_data);
-                free(file_data);
-                file_data = new_data;
-            }
-        }
-    }
-
-    size_t fd_len = strlen(file_data);
-
-    struct file_data fd;
-    fd.data = file_data;
-    fd.length = fd_len;
-    fd.index = 0;
-    fd.freed = 0;
-    hmput(files_map, hash, fd);
+    struct file_data file_data;
+    file_data.data = data;
+    file_data.length = fd_len;
+    file_data.index = 0;
+    file_data.freed = 0;
+    hmput(fis_files_map, hash, file_data);
     (*env)->ReleaseStringUTFChars(env, jpath, path);
 }
 
@@ -159,7 +113,7 @@ jint JNICALL fis_read0_hook(JNIEnv* env, jobject thiz) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash || file->value.freed) {
         return -1;
     }
@@ -183,7 +137,7 @@ jlong JNICALL fis_length0_hook(JNIEnv* env, jobject thiz) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash) {
         return -1;
     }
@@ -201,7 +155,7 @@ jlong JNICALL fis_position0_hook(JNIEnv* env, jobject thiz) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash) {
         return -1;
     }
@@ -219,7 +173,7 @@ jlong JNICALL fis_skip0_hook(JNIEnv* env, jobject thiz, jlong n) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash) {
         return 0;
     }
@@ -248,7 +202,7 @@ jint JNICALL fis_available0_hook(JNIEnv* env, jobject thiz) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash) {
         return 0;
     }
@@ -267,7 +221,7 @@ void JNICALL fis_close_hook(JNIEnv* env, jobject thiz) {
 
     jint hash = (*env)->CallIntMethod(env, thiz, hash_code_method);
 
-    struct file *file = hmgetp(files_map, hash);
+    struct file *file = hmgetp(fis_files_map, hash);
     if (file->key != hash) {
         return;
     }

src/fis_hook.h

@@ -4,22 +4,22 @@
 #include <jvmti.h>
 #include <jni.h>
 
-typedef void (JNICALL *open0_t)(JNIEnv*, jobject, jstring);
-typedef jint (JNICALL *readBytes_t)(JNIEnv*, jobject, jbyteArray, jint, jint);
-typedef jint (JNICALL *read0_t)(JNIEnv*, jobject);
-typedef jlong (JNICALL *length0_t)(JNIEnv*, jobject);
-typedef jlong (JNICALL *position0_t)(JNIEnv*, jobject);
-typedef jlong (JNICALL *skip0_t)(JNIEnv*, jobject, jlong);
-typedef jint (JNICALL *available0_t)(JNIEnv*, jobject);
-typedef void (JNICALL *close_t)(JNIEnv*, jobject);
-extern readBytes_t fis_real_readBytes;
-extern open0_t fis_real_open0;
-extern read0_t fis_real_read0;
-extern length0_t fis_real_length0;
-extern position0_t fis_real_position0;
-extern skip0_t fis_real_skip0;
-extern available0_t fis_real_available0;
-extern close_t fis_real_close;
+typedef void (JNICALL *fis_open0_t)(JNIEnv*, jobject, jstring);
+typedef jint (JNICALL *fis_readBytes_t)(JNIEnv*, jobject, jbyteArray, jint, jint);
+typedef jint (JNICALL *fis_read0_t)(JNIEnv*, jobject);
+typedef jlong (JNICALL *fis_length0_t)(JNIEnv*, jobject);
+typedef jlong (JNICALL *fis_position0_t)(JNIEnv*, jobject);
+typedef jlong (JNICALL *fis_skip0_t)(JNIEnv*, jobject, jlong);
+typedef jint (JNICALL *fis_available0_t)(JNIEnv*, jobject);
+typedef void (JNICALL *fis_close_t)(JNIEnv*, jobject);
+extern fis_readBytes_t fis_real_readBytes;
+extern fis_open0_t fis_real_open0;
+extern fis_read0_t fis_real_read0;
+extern fis_length0_t fis_real_length0;
+extern fis_position0_t fis_real_position0;
+extern fis_skip0_t fis_real_skip0;
+extern fis_available0_t fis_real_available0;
+extern fis_close_t fis_real_close;
 
 jint JNICALL fis_readBytes_hook(JNIEnv* env, jobject thiz, jbyteArray buf, jint off, jint len);
 void JNICALL fis_open0_hook(JNIEnv* env, jobject thiz, jstring jpath);

src/substagent.c

@@ -7,6 +7,7 @@
 #include <string.h>
 #include <stdio.h>
 #include "build_info.h"
+#include "fdi_hook.h"
 #include "fis_hook.h"
 #include "utils.h"
 
@@ -25,37 +26,49 @@ static void JNICALL onNativeMethodBind(jvmtiEnv* jvmti_env, JNIEnv* env, jthread
         if (strcmp(csig, "Ljava/io/FileInputStream;") == 0) {
             // private native void open0(String name)
             if (strcmp(mname, "open0") == 0 && strcmp(msig, "(Ljava/lang/String;)V") == 0) {
-                fis_real_open0 = (open0_t)address;
+                fis_real_open0 = (fis_open0_t)address;
                 *new_address_ptr = (void*)&fis_open0_hook;
             // private native int readBytes(byte b[], int off, int len)
             } else if (strcmp(mname, "readBytes") == 0 && strcmp(msig, "([BII)I") == 0) {
-                fis_real_readBytes = (readBytes_t)address;
+                fis_real_readBytes = (fis_readBytes_t)address;
                 *new_address_ptr = (void*)&fis_readBytes_hook;
             // private native int read0
             } else if (strcmp(mname, "read0") == 0 && strcmp(msig, "()I") == 0) {
-                fis_real_read0 = (read0_t)address;
+                fis_real_read0 = (fis_read0_t)address;
                 *new_address_ptr = (void*)&fis_read0_hook;
             // private native long length0()
             } else if (strcmp(mname, "length0") == 0 && strcmp(msig, "()J") == 0) {
-                fis_real_length0 = (length0_t)address;
+                fis_real_length0 = (fis_length0_t)address;
                 *new_address_ptr = (void*)&fis_length0_hook;
             // private native long position0()
             } else if (strcmp(mname, "position0") == 0 && strcmp(msig, "()J") == 0) {
-                fis_real_position0 = (position0_t)address;
+                fis_real_position0 = (fis_position0_t)address;
                 *new_address_ptr = (void*)&fis_position0_hook;
             // private native long skip0(long n)
             } else if (strcmp(mname, "skip0") == 0 && strcmp(msig, "(J)J") == 0) {
-                fis_real_skip0 = (skip0_t)address;
+                fis_real_skip0 = (fis_skip0_t)address;
                 *new_address_ptr = (void*)&fis_skip0_hook;
             // private native int available0()
             } else if (strcmp(mname, "available0") == 0 && strcmp(msig, "()I") == 0) {
-                fis_real_available0 = (available0_t)address;
+                fis_real_available0 = (fis_available0_t)address;
                 *new_address_ptr = (void*)&fis_available0_hook;
             // public void close()
             } else if (strcmp(mname, "close") == 0 && strcmp(msig, "()V") == 0) {
-                fis_real_close = (close_t)address;
+                fis_real_close = (fis_close_t)address;
                 *new_address_ptr = (void*)&fis_close_hook;
             }
+        } else if (strcmp(csig, "Lsun/nio/fs/UnixNativeDispatcher;") == 0) {
+            // private static native int open0(long pathAddress, int flags, int mode)
+            if (strcmp(mname, "open0") == 0 && strcmp(msig, "(JII)I") == 0) {
+                und_real_open0 = (und_open0_t)address;
+                *new_address_ptr = (void*)&und_open0_hook;
+            }
+        } else if (strcmp(csig, "Lsun/nio/ch/FileDispatcherImpl;") == 0) {
+            // static native int read0(FileDescriptor fd, long address, int len)
+            if (strcmp(mname, "read0") == 0 && strcmp(msig, "(Ljava/io/FileDescriptor;JI)I") == 0) {
+                fdi_real_read0 = (fdi_read0_t)address;
+                *new_address_ptr = (void*)&fdi_read0_hook;
+            }
         }
     }
 

src/utils.c

@@ -42,4 +42,57 @@ char* substitute(const char* value, int dollar_sign_matched_index, size_t i, siz
     assert(dollar_sign_matched_index+value_len+after_len == new_len);
     new_data[new_len] = '\0';
     return new_data;
+}
+
+void parse_file(char **data_ptr, size_t fsize) {
+    char *data = *data_ptr;
+    int dollar_sign_matched_index = -1;
+    char env_var[4096];
+    env_var[0] = '\0';
+    for (size_t i = 0; i < fsize; i++) {
+        char c = data[i];
+        if (dollar_sign_matched_index != -1) {
+            if ((c >= 48 && c <= 57) || (c >= 65 && c <= 90) || (c >= 97 && c <= 122) || c == 95) {
+                size_t len = strlen(env_var);
+                env_var[len] = c;
+                env_var[len + 1] = '\0';
+            } else {
+                if (strlen(env_var) == 0) continue;
+                char* value = getenv(env_var);
+                if (!value) {
+                    dollar_sign_matched_index = -1;
+                    env_var[0] = '\0';
+                    continue;
+                }
+
+                size_t env_len = i - dollar_sign_matched_index;
+
+                char* new_data = substitute(value, dollar_sign_matched_index, i, env_len, data);
+                free(data);
+                data = new_data;
+                *data_ptr = new_data;
+
+                dollar_sign_matched_index = -1;
+                env_var[0] = '\0';
+                continue;
+            }
+        } else {
+            if (c == '$') {
+                dollar_sign_matched_index = i;
+            }
+        }
+    }
+    if (dollar_sign_matched_index != -1) {
+        if (strlen(env_var) != 0) {
+            char* value = getenv(env_var);
+            if (value) {
+                size_t env_len = fsize - dollar_sign_matched_index;
+
+                char* new_data = substitute(value, dollar_sign_matched_index, fsize, env_len, data);
+                free(data);
+                data = new_data;
+                *data_ptr = new_data;
+            }
+        }
+    }
 }

src/utils.h

@@ -10,6 +10,7 @@ void tag(jobject obj);
 int has_tag(jobject obj);
 int is_config_path(const char* path);
 char* substitute(const char* value, int dollar_sign_matched_index, size_t i, size_t env_len, const char *data);
+void parse_file(char **data_ptr, size_t fsize);
 
 struct file_data {
     char* data;