| /* |
| * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| #include "jni.h" |
| #include "jni_util.h" |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <unistd.h> |
| #include <signal.h> |
| #include <dirent.h> |
| #include <ctype.h> |
| #include <sys/types.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <sys/stat.h> |
| #include <sys/un.h> |
| |
| #include "sun_tools_attach_LinuxVirtualMachine.h" |
| |
| #define RESTARTABLE(_cmd, _result) do { \ |
| do { \ |
| _result = _cmd; \ |
| } while((_result == -1) && (errno == EINTR)); \ |
| } while(0) |
| |
| /* |
| * Defines a callback that is invoked for each process |
| */ |
| typedef void (*ProcessCallback)(const pid_t pid, void* user_data); |
| |
| /* |
| * Invokes the callback function for each process |
| */ |
| static void forEachProcess(ProcessCallback f, void* user_data) { |
| DIR* dir; |
| struct dirent* ptr; |
| |
| /* |
| * To locate the children we scan /proc looking for files that have a |
| * position integer as a filename. |
| */ |
| if ((dir = opendir("/proc")) == NULL) { |
| return; |
| } |
| while ((ptr = readdir(dir)) != NULL) { |
| pid_t pid; |
| |
| /* skip current/parent directories */ |
| if (strcmp(ptr->d_name, ".") == 0 || strcmp(ptr->d_name, "..") == 0) { |
| continue; |
| } |
| |
| /* skip files that aren't numbers */ |
| pid = (pid_t)atoi(ptr->d_name); |
| if ((int)pid <= 0) { |
| continue; |
| } |
| |
| /* invoke the callback */ |
| (*f)(pid, user_data); |
| } |
| closedir(dir); |
| } |
| |
| |
| /* |
| * Returns the parent pid of a given pid, or -1 if not found |
| */ |
| static pid_t getParent(pid_t pid) { |
| char state; |
| FILE* fp; |
| char stat[2048]; |
| int statlen; |
| char fn[32]; |
| int i, p; |
| char* s; |
| |
| /* |
| * try to open /proc/%d/stat |
| */ |
| sprintf(fn, "/proc/%d/stat", pid); |
| fp = fopen(fn, "r"); |
| if (fp == NULL) { |
| return -1; |
| } |
| |
| /* |
| * The format is: pid (command) state ppid ... |
| * As the command could be anything we must find the right most |
| * ")" and then skip the white spaces that follow it. |
| */ |
| statlen = fread(stat, 1, 2047, fp); |
| stat[statlen] = '\0'; |
| fclose(fp); |
| s = strrchr(stat, ')'); |
| if (s == NULL) { |
| return -1; |
| } |
| do s++; while (isspace(*s)); |
| i = sscanf(s, "%c %d", &state, &p); |
| return (pid_t)p; |
| } |
| |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: socket |
| * Signature: ()I |
| */ |
| JNIEXPORT jint JNICALL Java_sun_tools_attach_LinuxVirtualMachine_socket |
| (JNIEnv *env, jclass cls) |
| { |
| int fd = socket(PF_UNIX, SOCK_STREAM, 0); |
| if (fd == -1) { |
| JNU_ThrowIOExceptionWithLastError(env, "socket"); |
| } |
| return (jint)fd; |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: connect |
| * Signature: (ILjava/lang/String;)I |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_connect |
| (JNIEnv *env, jclass cls, jint fd, jstring path) |
| { |
| jboolean isCopy; |
| const char* p = GetStringPlatformChars(env, path, &isCopy); |
| if (p != NULL) { |
| struct sockaddr_un addr; |
| int err = 0; |
| |
| addr.sun_family = AF_UNIX; |
| strcpy(addr.sun_path, p); |
| |
| if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) { |
| err = errno; |
| } |
| |
| if (isCopy) { |
| JNU_ReleaseStringPlatformChars(env, path, p); |
| } |
| |
| /* |
| * If the connect failed then we throw the appropriate exception |
| * here (can't throw it before releasing the string as can't call |
| * JNI with pending exception) |
| */ |
| if (err != 0) { |
| if (err == ENOENT) { |
| JNU_ThrowByName(env, "java/io/FileNotFoundException", NULL); |
| } else { |
| char* msg = strdup(strerror(err)); |
| JNU_ThrowIOException(env, msg); |
| if (msg != NULL) { |
| free(msg); |
| } |
| } |
| } |
| } |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: isLinuxThreads |
| * Signature: ()V |
| */ |
| JNIEXPORT jboolean JNICALL Java_sun_tools_attach_LinuxVirtualMachine_isLinuxThreads |
| (JNIEnv *env, jclass cls) |
| { |
| # ifndef _CS_GNU_LIBPTHREAD_VERSION |
| # define _CS_GNU_LIBPTHREAD_VERSION 3 |
| # endif |
| size_t n; |
| char* s; |
| jboolean res; |
| |
| n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); |
| if (n <= 0) { |
| /* glibc before 2.3.2 only has LinuxThreads */ |
| return JNI_TRUE; |
| } |
| |
| s = (char *)malloc(n); |
| if (s == NULL) { |
| JNU_ThrowOutOfMemoryError(env, "malloc failed"); |
| return JNI_TRUE; |
| } |
| confstr(_CS_GNU_LIBPTHREAD_VERSION, s, n); |
| |
| /* |
| * If the LIBPTHREAD version include "NPTL" then we know we |
| * have the new threads library and not LinuxThreads |
| */ |
| res = (jboolean)(strstr(s, "NPTL") == NULL); |
| free(s); |
| return res; |
| } |
| |
| /* |
| * Structure and callback function used to count the children of |
| * a given process, and record the pid of the "manager thread". |
| */ |
| typedef struct { |
| pid_t ppid; |
| int count; |
| pid_t mpid; |
| } ChildCountContext; |
| |
| static void ChildCountCallback(const pid_t pid, void* user_data) { |
| ChildCountContext* context = (ChildCountContext*)user_data; |
| if (getParent(pid) == context->ppid) { |
| context->count++; |
| /* |
| * Remember the pid of the first child. If the final count is |
| * one then this is the pid of the LinuxThreads manager. |
| */ |
| if (context->count == 1) { |
| context->mpid = pid; |
| } |
| } |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: getLinuxThreadsManager |
| * Signature: (I)I |
| */ |
| JNIEXPORT jint JNICALL Java_sun_tools_attach_LinuxVirtualMachine_getLinuxThreadsManager |
| (JNIEnv *env, jclass cls, jint pid) |
| { |
| ChildCountContext context; |
| |
| /* |
| * Iterate over all processes to find how many children 'pid' has |
| */ |
| context.ppid = pid; |
| context.count = 0; |
| context.mpid = (pid_t)0; |
| forEachProcess(ChildCountCallback, (void*)&context); |
| |
| /* |
| * If there's no children then this is likely the pid of the primordial |
| * created by the launcher - in that case the LinuxThreads manager is the |
| * parent of this process. |
| */ |
| if (context.count == 0) { |
| pid_t parent = getParent(pid); |
| if ((int)parent > 0) { |
| return (jint)parent; |
| } |
| } |
| |
| /* |
| * There's one child so this is likely the embedded VM case where the |
| * the primordial thread == LinuxThreads initial thread. The LinuxThreads |
| * manager in that case is the child. |
| */ |
| if (context.count == 1) { |
| return (jint)context.mpid; |
| } |
| |
| /* |
| * If we get here it's most likely we were given the wrong pid |
| */ |
| JNU_ThrowIOException(env, "Unable to get pid of LinuxThreads manager thread"); |
| return -1; |
| } |
| |
| /* |
| * Structure and callback function used to send a QUIT signal to all |
| * children of a given process |
| */ |
| typedef struct { |
| pid_t ppid; |
| } SendQuitContext; |
| |
| static void SendQuitCallback(const pid_t pid, void* user_data) { |
| SendQuitContext* context = (SendQuitContext*)user_data; |
| pid_t parent = getParent(pid); |
| if (parent == context->ppid) { |
| kill(pid, SIGQUIT); |
| } |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: sendQuitToChildrenOf |
| * Signature: (I)V |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_sendQuitToChildrenOf |
| (JNIEnv *env, jclass cls, jint pid) |
| { |
| SendQuitContext context; |
| context.ppid = (pid_t)pid; |
| |
| /* |
| * Iterate over all children of 'pid' and send a QUIT signal to each. |
| */ |
| forEachProcess(SendQuitCallback, (void*)&context); |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: sendQuitTo |
| * Signature: (I)V |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_sendQuitTo |
| (JNIEnv *env, jclass cls, jint pid) |
| { |
| if (kill((pid_t)pid, SIGQUIT)) { |
| JNU_ThrowIOExceptionWithLastError(env, "kill"); |
| } |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: checkPermissions |
| * Signature: (Ljava/lang/String;)V |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_checkPermissions |
| (JNIEnv *env, jclass cls, jstring path) |
| { |
| jboolean isCopy; |
| const char* p = GetStringPlatformChars(env, path, &isCopy); |
| if (p != NULL) { |
| struct stat64 sb; |
| uid_t uid, gid; |
| int res; |
| |
| /* |
| * Check that the path is owned by the effective uid/gid of this |
| * process. Also check that group/other access is not allowed. |
| */ |
| uid = geteuid(); |
| gid = getegid(); |
| |
| res = stat64(p, &sb); |
| if (res != 0) { |
| /* save errno */ |
| res = errno; |
| } |
| |
| /* release p here before we throw an I/O exception */ |
| if (isCopy) { |
| JNU_ReleaseStringPlatformChars(env, path, p); |
| } |
| |
| if (res == 0) { |
| if ( (sb.st_uid != uid) || (sb.st_gid != gid) || |
| ((sb.st_mode & (S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) != 0) ) { |
| JNU_ThrowIOException(env, "well-known file is not secure"); |
| } |
| } else { |
| char* msg = strdup(strerror(res)); |
| JNU_ThrowIOException(env, msg); |
| if (msg != NULL) { |
| free(msg); |
| } |
| } |
| } |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: close |
| * Signature: (I)V |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_close |
| (JNIEnv *env, jclass cls, jint fd) |
| { |
| int res; |
| RESTARTABLE(close(fd), res); |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: read |
| * Signature: (I[BI)I |
| */ |
| JNIEXPORT jint JNICALL Java_sun_tools_attach_LinuxVirtualMachine_read |
| (JNIEnv *env, jclass cls, jint fd, jbyteArray ba, jint off, jint baLen) |
| { |
| unsigned char buf[128]; |
| size_t len = sizeof(buf); |
| ssize_t n; |
| |
| size_t remaining = (size_t)(baLen - off); |
| if (len > remaining) { |
| len = remaining; |
| } |
| |
| RESTARTABLE(read(fd, buf+off, len), n); |
| if (n == -1) { |
| JNU_ThrowIOExceptionWithLastError(env, "read"); |
| } else { |
| if (n == 0) { |
| n = -1; // EOF |
| } else { |
| (*env)->SetByteArrayRegion(env, ba, off, (jint)n, (jbyte *)(buf+off)); |
| } |
| } |
| return n; |
| } |
| |
| /* |
| * Class: sun_tools_attach_LinuxVirtualMachine |
| * Method: write |
| * Signature: (I[B)V |
| */ |
| JNIEXPORT void JNICALL Java_sun_tools_attach_LinuxVirtualMachine_write |
| (JNIEnv *env, jclass cls, jint fd, jbyteArray ba, jint off, jint bufLen) |
| { |
| size_t remaining = bufLen; |
| do { |
| unsigned char buf[128]; |
| size_t len = sizeof(buf); |
| int n; |
| |
| if (len > remaining) { |
| len = remaining; |
| } |
| (*env)->GetByteArrayRegion(env, ba, off, len, (jbyte *)buf); |
| |
| RESTARTABLE(write(fd, buf, len), n); |
| if (n > 0) { |
| off += n; |
| remaining -= n; |
| } else { |
| JNU_ThrowIOExceptionWithLastError(env, "write"); |
| return; |
| } |
| |
| } while (remaining > 0); |
| } |