| /* |
| * Copyright 1995-2006 Sun Microsystems, Inc. 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. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| #undef _LARGEFILE64_SOURCE |
| #define _LARGEFILE64_SOURCE 1 |
| |
| #include "jni.h" |
| #include "jvm.h" |
| #include "jvm_md.h" |
| #include "jni_util.h" |
| #include "io_util.h" |
| |
| /* |
| * Platform-specific support for java.lang.Process |
| */ |
| #include <assert.h> |
| #include <stddef.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <ctype.h> |
| #include <wait.h> |
| #include <signal.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <dirent.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| |
| #ifndef STDIN_FILENO |
| #define STDIN_FILENO 0 |
| #endif |
| |
| #ifndef STDOUT_FILENO |
| #define STDOUT_FILENO 1 |
| #endif |
| |
| #ifndef STDERR_FILENO |
| #define STDERR_FILENO 2 |
| #endif |
| |
| #ifndef SA_NOCLDSTOP |
| #define SA_NOCLDSTOP 0 |
| #endif |
| |
| #ifndef SA_RESTART |
| #define SA_RESTART 0 |
| #endif |
| |
| #define FAIL_FILENO (STDERR_FILENO + 1) |
| |
| static void |
| setSIGCHLDHandler(JNIEnv *env) |
| { |
| /* There is a subtle difference between having the signal handler |
| * for SIGCHLD be SIG_DFL and SIG_IGN. We cannot obtain process |
| * termination information for child processes if the signal |
| * handler is SIG_IGN. It must be SIG_DFL. |
| * |
| * We used to set the SIGCHLD handler only on Linux, but it's |
| * safest to set it unconditionally. |
| * |
| * Consider what happens if java's parent process sets the SIGCHLD |
| * handler to SIG_IGN. Normally signal handlers are inherited by |
| * children, but SIGCHLD is a controversial case. Solaris appears |
| * to always reset it to SIG_DFL, but this behavior may be |
| * non-standard-compliant, and we shouldn't rely on it. |
| * |
| * References: |
| * http://www.opengroup.org/onlinepubs/7908799/xsh/exec.html |
| * http://www.pasc.org/interps/unofficial/db/p1003.1/pasc-1003.1-132.html |
| */ |
| struct sigaction sa; |
| sa.sa_handler = SIG_DFL; |
| sigemptyset(&sa.sa_mask); |
| sa.sa_flags = SA_NOCLDSTOP | SA_RESTART; |
| if (sigaction(SIGCHLD, &sa, NULL) < 0) |
| JNU_ThrowInternalError(env, "Can't set SIGCHLD handler"); |
| } |
| |
| static void* |
| xmalloc(JNIEnv *env, size_t size) |
| { |
| void *p = malloc(size); |
| if (p == NULL) |
| JNU_ThrowOutOfMemoryError(env, NULL); |
| return p; |
| } |
| |
| #define NEW(type, n) ((type *) xmalloc(env, (n) * sizeof(type))) |
| |
| /** |
| * If PATH is not defined, the OS provides some default value. |
| * Unfortunately, there's no portable way to get this value. |
| * Fortunately, it's only needed if the child has PATH while we do not. |
| */ |
| static const char* |
| defaultPath(void) |
| { |
| #ifdef __solaris__ |
| /* These really are the Solaris defaults! */ |
| return (geteuid() == 0 || getuid() == 0) ? |
| "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:/usr/sbin" : |
| "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:"; |
| #else |
| return ":/bin:/usr/bin"; /* glibc */ |
| #endif |
| } |
| |
| static const char* |
| effectivePath(void) |
| { |
| const char *s = getenv("PATH"); |
| return (s != NULL) ? s : defaultPath(); |
| } |
| |
| static int |
| countOccurrences(const char *s, char c) |
| { |
| int count; |
| for (count = 0; *s != '\0'; s++) |
| count += (*s == c); |
| return count; |
| } |
| |
| static const char * const * |
| splitPath(JNIEnv *env, const char *path) |
| { |
| const char *p, *q; |
| char **pathv; |
| int i; |
| int count = countOccurrences(path, ':') + 1; |
| |
| pathv = NEW(char*, count+1); |
| pathv[count] = NULL; |
| for (p = path, i = 0; i < count; i++, p = q + 1) { |
| for (q = p; (*q != ':') && (*q != '\0'); q++) |
| ; |
| if (q == p) /* empty PATH component => "." */ |
| pathv[i] = "./"; |
| else { |
| int addSlash = ((*(q - 1)) != '/'); |
| pathv[i] = NEW(char, q - p + addSlash + 1); |
| memcpy(pathv[i], p, q - p); |
| if (addSlash) |
| pathv[i][q - p] = '/'; |
| pathv[i][q - p + addSlash] = '\0'; |
| } |
| } |
| return (const char * const *) pathv; |
| } |
| |
| /** |
| * Cached value of JVM's effective PATH. |
| * (We don't support putenv("PATH=...") in native code) |
| */ |
| static const char *parentPath; |
| |
| /** |
| * Split, canonicalized version of parentPath |
| */ |
| static const char * const *parentPathv; |
| |
| static jfieldID field_exitcode; |
| |
| JNIEXPORT void JNICALL |
| Java_java_lang_UNIXProcess_initIDs(JNIEnv *env, jclass clazz) |
| { |
| field_exitcode = (*env)->GetFieldID(env, clazz, "exitcode", "I"); |
| |
| parentPath = effectivePath(); |
| parentPathv = splitPath(env, parentPath); |
| |
| setSIGCHLDHandler(env); |
| } |
| |
| |
| #ifndef WIFEXITED |
| #define WIFEXITED(status) (((status)&0xFF) == 0) |
| #endif |
| |
| #ifndef WEXITSTATUS |
| #define WEXITSTATUS(status) (((status)>>8)&0xFF) |
| #endif |
| |
| #ifndef WIFSIGNALED |
| #define WIFSIGNALED(status) (((status)&0xFF) > 0 && ((status)&0xFF00) == 0) |
| #endif |
| |
| #ifndef WTERMSIG |
| #define WTERMSIG(status) ((status)&0x7F) |
| #endif |
| |
| /* Block until a child process exits and return its exit code. |
| Note, can only be called once for any given pid. */ |
| JNIEXPORT jint JNICALL |
| Java_java_lang_UNIXProcess_waitForProcessExit(JNIEnv* env, |
| jobject junk, |
| jint pid) |
| { |
| /* We used to use waitid() on Solaris, waitpid() on Linux, but |
| * waitpid() is more standard, so use it on all POSIX platforms. */ |
| int status; |
| /* Wait for the child process to exit. This returns immediately if |
| the child has already exited. */ |
| while (waitpid(pid, &status, 0) < 0) { |
| switch (errno) { |
| case ECHILD: return 0; |
| case EINTR: break; |
| default: return -1; |
| } |
| } |
| |
| if (WIFEXITED(status)) { |
| /* |
| * The child exited normally; get its exit code. |
| */ |
| return WEXITSTATUS(status); |
| } else if (WIFSIGNALED(status)) { |
| /* The child exited because of a signal. |
| * The best value to return is 0x80 + signal number, |
| * because that is what all Unix shells do, and because |
| * it allows callers to distinguish between process exit and |
| * process death by signal. |
| * Unfortunately, the historical behavior on Solaris is to return |
| * the signal number, and we preserve this for compatibility. */ |
| #ifdef __solaris__ |
| return WTERMSIG(status); |
| #else |
| return 0x80 + WTERMSIG(status); |
| #endif |
| } else { |
| /* |
| * Unknown exit code; pass it through. |
| */ |
| return status; |
| } |
| } |
| |
| static int |
| closeDescriptors(void) |
| { |
| DIR *dp; |
| struct dirent64 *dirp; |
| int from_fd = FAIL_FILENO + 1; |
| |
| /* We're trying to close all file descriptors, but opendir() might |
| * itself be implemented using a file descriptor, and we certainly |
| * don't want to close that while it's in use. We assume that if |
| * opendir() is implemented using a file descriptor, then it uses |
| * the lowest numbered file descriptor, just like open(). So we |
| * close a couple explicitly. */ |
| |
| close(from_fd); /* for possible use by opendir() */ |
| close(from_fd + 1); /* another one for good luck */ |
| |
| if ((dp = opendir("/proc/self/fd")) == NULL) |
| return 0; |
| |
| /* We use readdir64 instead of readdir to work around Solaris bug |
| * 6395699: /proc/self/fd fails to report file descriptors >= 1024 on Solaris 9 |
| */ |
| while ((dirp = readdir64(dp)) != NULL) { |
| int fd; |
| if (isdigit(dirp->d_name[0]) && |
| (fd = strtol(dirp->d_name, NULL, 10)) >= from_fd + 2) |
| close(fd); |
| } |
| |
| closedir(dp); |
| |
| return 1; |
| } |
| |
| static void |
| moveDescriptor(int fd_from, int fd_to) |
| { |
| if (fd_from != fd_to) { |
| dup2(fd_from, fd_to); |
| close(fd_from); |
| } |
| } |
| |
| static const char * |
| getBytes(JNIEnv *env, jbyteArray arr) |
| { |
| return arr == NULL ? NULL : |
| (const char*) (*env)->GetByteArrayElements(env, arr, NULL); |
| } |
| |
| static void |
| releaseBytes(JNIEnv *env, jbyteArray arr, const char* parr) |
| { |
| if (parr != NULL) |
| (*env)->ReleaseByteArrayElements(env, arr, (jbyte*) parr, JNI_ABORT); |
| } |
| |
| static void |
| initVectorFromBlock(const char**vector, const char* block, int count) |
| { |
| int i; |
| const char *p; |
| for (i = 0, p = block; i < count; i++) { |
| /* Invariant: p always points to the start of a C string. */ |
| vector[i] = p; |
| while (*(p++)); |
| } |
| vector[count] = NULL; |
| } |
| |
| static void |
| throwIOException(JNIEnv *env, int errnum, const char *defaultDetail) |
| { |
| static const char * const format = "error=%d, %s"; |
| const char *detail = defaultDetail; |
| char *errmsg; |
| jstring s; |
| |
| if (errnum != 0) { |
| const char *s = strerror(errnum); |
| if (strcmp(s, "Unknown error") != 0) |
| detail = s; |
| } |
| /* ASCII Decimal representation uses 2.4 times as many bits as binary. */ |
| errmsg = NEW(char, strlen(format) + strlen(detail) + 3 * sizeof(errnum)); |
| sprintf(errmsg, format, errnum, detail); |
| s = JNU_NewStringPlatform(env, errmsg); |
| if (s != NULL) { |
| jobject x = JNU_NewObjectByName(env, "java/io/IOException", |
| "(Ljava/lang/String;)V", s); |
| if (x != NULL) |
| (*env)->Throw(env, x); |
| } |
| free(errmsg); |
| } |
| |
| #ifdef DEBUG_PROCESS |
| /* Debugging process code is difficult; where to write debug output? */ |
| static void |
| debugPrint(char *format, ...) |
| { |
| FILE *tty = fopen("/dev/tty", "w"); |
| va_list ap; |
| va_start(ap, format); |
| vfprintf(tty, format, ap); |
| va_end(ap); |
| fclose(tty); |
| } |
| #endif /* DEBUG_PROCESS */ |
| |
| /* Version of execvpe when child's PATH differs from parent's */ |
| static int |
| execvp_usingParentPath(const char *file, const char *const argv[]) |
| { |
| char expanded_file[PATH_MAX]; |
| int filelen = strlen(file); |
| int sticky_errno = 0; |
| const char * const * dirs; |
| /* Search parent's PATH */ |
| for (dirs = parentPathv; *dirs; dirs++) { |
| const char * dir = *dirs; |
| int dirlen = strlen(dir); |
| if (filelen + dirlen + 1 >= PATH_MAX) { |
| /* Resist the urge to remove this limit; |
| * calling malloc after fork is unsafe. */ |
| errno = ENAMETOOLONG; |
| continue; |
| } |
| strcpy(expanded_file, dir); |
| strcpy(expanded_file + dirlen, file); |
| execvp(expanded_file, (char **) argv); |
| /* There are 3 responses to various classes of errno: |
| * return immediately, continue (especially for ENOENT), |
| * or continue with "sticky" errno. |
| * |
| * From exec(3): |
| * |
| * If permission is denied for a file (the attempted |
| * execve returned EACCES), these functions will continue |
| * searching the rest of the search path. If no other |
| * file is found, however, they will return with the |
| * global variable errno set to EACCES. |
| */ |
| switch (errno) { |
| case EACCES: |
| sticky_errno = errno; |
| /* FALLTHRU */ |
| case ENOENT: |
| case ENOTDIR: |
| #ifdef ELOOP |
| case ELOOP: |
| #endif |
| #ifdef ESTALE |
| case ESTALE: |
| #endif |
| #ifdef ENODEV |
| case ENODEV: |
| #endif |
| #ifdef ETIMEDOUT |
| case ETIMEDOUT: |
| #endif |
| break; /* Try other directories in PATH */ |
| default: |
| return -1; |
| } |
| } |
| if (sticky_errno != 0) |
| errno = sticky_errno; |
| return -1; |
| } |
| |
| /* execvpe should have been included in the Unix standards. */ |
| static int |
| execvpe(const char *file, const char *const argv[], const char *const envp[]) |
| { |
| /* This is one of the rare times it's more portable to declare an |
| * external symbol explicitly, rather than via a system header. |
| * The declaration is standardized as part of UNIX98, but there is |
| * no standard (not even de-facto) header file where the |
| * declaration is to be found. See: |
| * http://www.opengroup.org/onlinepubs/009695399/functions/environ.html |
| * http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_02.html |
| * |
| * "All identifiers in this volume of IEEE Std 1003.1-2001, except |
| * environ, are defined in at least one of the headers" (!) |
| */ |
| extern char **environ; |
| |
| if (envp != NULL) |
| environ = (char **) envp; |
| |
| if (/* Parent and child environment the same? Use child PATH. */ |
| (envp == NULL) |
| |
| /* http://www.opengroup.org/onlinepubs/009695399/functions/exec.html |
| * "If the file argument contains a slash character, it is used as |
| * the pathname for this file. Otherwise, the path prefix for this |
| * file is obtained by a search of the directories passed in the |
| * PATH environment variable" */ |
| || (strchr(file, '/') != NULL) |
| |
| /* Parent and child PATH the same? Use child PATH. */ |
| || (strcmp(parentPath, effectivePath()) == 0) |
| |
| /* We want ENOENT, not EACCES, for zero-length program names. */ |
| || (*file == '\0')) |
| |
| return execvp(file, (char **) argv); |
| else |
| return execvp_usingParentPath(file, argv); |
| } |
| |
| static void |
| closeSafely(int fd) |
| { |
| if (fd != -1) |
| close(fd); |
| } |
| |
| #ifndef __solaris__ |
| #undef fork1 |
| #define fork1() fork() |
| #endif |
| |
| JNIEXPORT jint JNICALL |
| Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env, |
| jobject process, |
| jbyteArray prog, |
| jbyteArray argBlock, jint argc, |
| jbyteArray envBlock, jint envc, |
| jbyteArray dir, |
| jboolean redirectErrorStream, |
| jobject stdin_fd, |
| jobject stdout_fd, |
| jobject stderr_fd) |
| { |
| int errnum; |
| int resultPid = -1; |
| int in[2], out[2], err[2], fail[2]; |
| const char **argv = NULL; |
| const char **envv = NULL; |
| const char *pprog = getBytes(env, prog); |
| const char *pargBlock = getBytes(env, argBlock); |
| const char *penvBlock = getBytes(env, envBlock); |
| const char *pdir = getBytes(env, dir); |
| |
| in[0] = in[1] = out[0] = out[1] = err[0] = err[1] = fail[0] = fail[1] = -1; |
| |
| assert(prog != NULL && argBlock != NULL); |
| if (pprog == NULL) goto Catch; |
| if (pargBlock == NULL) goto Catch; |
| if (envBlock != NULL && penvBlock == NULL) goto Catch; |
| if (dir != NULL && pdir == NULL) goto Catch; |
| |
| /* Convert pprog + pargBlock into a char ** argv */ |
| if ((argv = NEW(const char *, argc + 2)) == NULL) |
| goto Catch; |
| argv[0] = pprog; |
| initVectorFromBlock(argv+1, pargBlock, argc); |
| |
| if (envBlock != NULL) { |
| /* Convert penvBlock into a char ** envv */ |
| if ((envv = NEW(const char *, envc + 1)) == NULL) |
| goto Catch; |
| initVectorFromBlock(envv, penvBlock, envc); |
| } |
| |
| if ((pipe(in) < 0) || |
| (pipe(out) < 0) || |
| (pipe(err) < 0) || |
| (pipe(fail) < 0)) { |
| throwIOException(env, errno, "Bad file descriptor"); |
| goto Catch; |
| } |
| |
| resultPid = fork1(); |
| if (resultPid < 0) { |
| throwIOException(env, errno, "Fork failed"); |
| goto Catch; |
| } |
| |
| if (resultPid == 0) { |
| /* Child process */ |
| |
| /* Close the parent sides of the pipe. |
| Give the child sides of the pipes the right fileno's. |
| Closing pipe fds here is redundant, since closeDescriptors() |
| would do it anyways, but a little paranoia is a good thing. */ |
| /* Note: it is possible for in[0] == 0 */ |
| close(in[1]); |
| moveDescriptor(in[0], STDIN_FILENO); |
| close(out[0]); |
| moveDescriptor(out[1], STDOUT_FILENO); |
| close(err[0]); |
| if (redirectErrorStream) { |
| close(err[1]); |
| dup2(STDOUT_FILENO, STDERR_FILENO); |
| } else { |
| moveDescriptor(err[1], STDERR_FILENO); |
| } |
| close(fail[0]); |
| moveDescriptor(fail[1], FAIL_FILENO); |
| |
| /* close everything */ |
| if (closeDescriptors() == 0) { /* failed, close the old way */ |
| int max_fd = (int)sysconf(_SC_OPEN_MAX); |
| int i; |
| for (i = FAIL_FILENO + 1; i < max_fd; i++) |
| close(i); |
| } |
| |
| /* change to the new working directory */ |
| if (pdir != NULL && chdir(pdir) < 0) |
| goto WhyCantJohnnyExec; |
| |
| if (fcntl(FAIL_FILENO, F_SETFD, FD_CLOEXEC) == -1) |
| goto WhyCantJohnnyExec; |
| |
| execvpe(argv[0], argv, envv); |
| |
| WhyCantJohnnyExec: |
| /* We used to go to an awful lot of trouble to predict whether the |
| * child would fail, but there is no reliable way to predict the |
| * success of an operation without *trying* it, and there's no way |
| * to try a chdir or exec in the parent. Instead, all we need is a |
| * way to communicate any failure back to the parent. Easy; we just |
| * send the errno back to the parent over a pipe in case of failure. |
| * The tricky thing is, how do we communicate the *success* of exec? |
| * We use FD_CLOEXEC together with the fact that a read() on a pipe |
| * yields EOF when the write ends (we have two of them!) are closed. |
| */ |
| errnum = errno; |
| write(FAIL_FILENO, &errnum, sizeof(errnum)); |
| close(FAIL_FILENO); |
| _exit(-1); |
| } |
| |
| /* parent process */ |
| |
| close(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec */ |
| if (read(fail[0], &errnum, sizeof(errnum)) != 0) { |
| waitpid(resultPid, NULL, 0); |
| throwIOException(env, errnum, "Exec failed"); |
| goto Catch; |
| } |
| |
| (*env)->SetIntField(env, stdin_fd, IO_fd_fdID, in [1]); |
| (*env)->SetIntField(env, stdout_fd, IO_fd_fdID, out[0]); |
| (*env)->SetIntField(env, stderr_fd, IO_fd_fdID, err[0]); |
| |
| Finally: |
| /* Always clean up the child's side of the pipes */ |
| closeSafely(in [0]); |
| closeSafely(out[1]); |
| closeSafely(err[1]); |
| |
| /* Always clean up fail descriptors */ |
| closeSafely(fail[0]); |
| closeSafely(fail[1]); |
| |
| free(argv); |
| free(envv); |
| |
| releaseBytes(env, prog, pprog); |
| releaseBytes(env, argBlock, pargBlock); |
| releaseBytes(env, envBlock, penvBlock); |
| releaseBytes(env, dir, pdir); |
| |
| return resultPid; |
| |
| Catch: |
| /* Clean up the parent's side of the pipes in case of failure only */ |
| closeSafely(in [1]); |
| closeSafely(out[0]); |
| closeSafely(err[0]); |
| goto Finally; |
| } |
| |
| JNIEXPORT void JNICALL |
| Java_java_lang_UNIXProcess_destroyProcess(JNIEnv *env, jobject junk, jint pid) |
| { |
| kill(pid, SIGTERM); |
| } |