--- /dev/null
+/* gcc -Wall -O2 -g chpid.c -o chpid */
+#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE_EXTENDED
+#define _SVID_SOURCE
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/mount.h>
+#include <sys/vfs.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sched.h>
+#include <stdarg.h>
+#include <dirent.h>
+
+#ifndef MNT_FORCE
+#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */
+#endif /* MNT_FORCE */
+#ifndef MNT_DETACH
+#define MNT_DETACH 0x00000002 /* Just detach from the tree */
+#endif /* MNT_DETACH */
+#ifndef MNT_EXPIRE
+#define MNT_EXPIRE 0x00000004 /* Mark for expiry */
+#endif /* MNT_EXPIRE */
+
+#ifndef MS_MOVE
+#define MS_MOVE 8192
+#endif
+#ifndef MS_REC
+#define MS_REC 16384
+#endif
+
+#ifdef OLD
+# ifndef CLONE_NPSPACE
+# define CLONE_NPSPACE 0x04000000 /* New process space */
+# endif
+# ifndef CLONE_NSYSVIPC
+# define CLONE_NSYSVIPC 0x08000000 /* New sysvipc space */
+# endif
+# ifndef CLONE_NHOST
+# define CLONE_NHOST 0x10000000 /* New networking host context (lo, hostname, etc) */
+# endif
+# ifndef CLONE_NDEV
+# define CLONE_NDEV 0x20000000 /* New hash of devices I can touch */
+# endif
+# ifndef CLONE_NUSERS
+# define CLONE_NUSERS 0x40000000 /* New users */
+# endif
+# ifndef CLONE_NTIME
+# define CLONE_NTIME 0x80000000 /* New time context??? */
+# endif
+# ifndef CLONE_NS_NOSUID
+# define CLONE_NS_NOSUID 0x00001000 /* Force MNT_NOSUID on all mounts in the namespace */
+# endif
+#endif
+
+#ifndef CLONE_NEWUTS
+#define CLONE_NEWUTS 0x04000000 /* New uts namespace (uname) */
+#endif
+#ifndef CLONE_NEWIPC
+#define CLONE_NEWIPC 0x08000000 /* New sysvipc namespace */
+#endif
+#ifndef CLONE_NEWUID
+#define CLONE_NEWUID 0x10000000 /* New users */
+#endif
+#ifndef CLONE_NEWNET
+#define CLONE_NEWNET 0x40000000 /* New network namespace (lo, device, names sockets, etc) */
+#endif
+#ifndef CLONE_NEWPID
+#define CLONE_NEWPID 0x80000000 /* New process space */
+#endif
+#ifndef CLONE_NEWTIME
+#define CLONE_NEWTIME 0x40000000 /* New time context??? */
+#endif
+#ifndef CLONE_NEWDEV
+#define CLONE_NEWDEV 0x00001000 /* New has of devices I can touch */
+#endif
+
+
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC 0x9fa0
+#endif /* PROC_SUPER_MAGIC */
+
+struct user_desc;
+static pid_t raw_clone(int flags, void *child_stack,
+ int *parent_tidptr, struct user_desc *newtls, int *child_tidptr)
+{
+ return syscall(__NR_clone, flags, child_stack, parent_tidptr, newtls, child_tidptr);
+}
+
+static int raw_pivot_root(const char *new_root, const char *old_root)
+{
+ return syscall(__NR_pivot_root, new_root, old_root);
+}
+
+static void (*my_exit)(int status) = exit;
+
+static void die(char *fmt, ...)
+{
+ va_list ap;
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ fflush(stderr);
+ fflush(stdout);
+ my_exit(1);
+}
+
+static void *xmalloc(size_t size)
+{
+ void *ptr;
+ ptr = malloc(size);
+ if (!ptr) die("malloc of %d bytes failed: %s\n", size, strerror(errno));
+ return ptr;
+}
+
+static void umount_buffer(char *line)
+{
+ char *next, *mnt, *end, *type;
+ int result;
+ if (!line || !*line)
+ return;
+ next = strchr(line, '\n');
+ *next++ = '0';
+ type = line;
+ mnt = strchr(line, ' ');
+ *mnt++ = '\0';
+ end = strchr(mnt, ' ');
+ *end = '\0';
+ umount_buffer(next);
+
+#if 0
+ /* For debugging list what I am unounting */
+ write(STDOUT_FILENO, mnt, strlen(mnt));
+ write(STDOUT_FILENO, "\n", 1);
+#endif
+
+ if (strcmp(type, "rootfs"))
+ return;
+ result = umount2(mnt, MNT_DETACH);
+ if (result < 0)
+ die("umount of '%s' failed: %d: %s\n",
+ mnt, errno, strerror(errno));
+}
+
+static void umount_all(void)
+{
+ static const char mounts[] = "/proc/self/mounts";
+ char *buf;
+ ssize_t bufsz, bytes;
+ int fd, result;
+ buf = NULL;
+ bufsz = 4096;
+
+ /* Temporarily mount /proc at / so I know I have it */
+ result = mount("proc", "/proc", "proc", 0, NULL);
+ if (result < 0)
+ die("mount of proc failed: %d: %s\n",
+ errno, strerror(errno));
+#if 0
+ DIR *dir;
+ struct dirent *entry;
+ dir = opendir("/");
+ while((entry = readdir(dir)) != NULL) {
+ write(STDOUT_FILENO, entry->d_name, strlen(entry->d_name));
+ write(STDOUT_FILENO, "\n", 1);
+ }
+ closedir(dir);
+#endif
+ fd = open(mounts, O_RDONLY);
+ if (fd < 0)
+ die("open of %s failed: %d: %s\n",
+ mounts, errno, strerror(errno));
+
+ /* Read in all of the mount points */
+ do {
+ buf = xmalloc(bufsz);
+ result = lseek(fd, 0, SEEK_SET);
+ if (result != 0)
+ die("lseek failed: %d:%s\n",
+ errno, strerror(errno));
+ bytes = read(fd, buf, bufsz);
+ if (bytes < 0)
+ die("Read of %s failed: %d:%s\n",
+ mounts, errno, strerror(errno));
+ if (bytes != bufsz) {
+ /* Terminate the buffer */
+ buf[bytes] = '\0';
+ } else {
+ /* Free the buffer and try again */
+ free(buf);
+ buf = NULL;
+ bufsz <<= 1;
+ }
+ } while(!buf);
+ /* Be good and close the file descriptor */
+ result = close(fd);
+ if (result < 0)
+ fprintf(stderr, "close of %s failed: %d:%s\n",
+ mounts, errno, strerror(errno));
+
+#if 0
+ /* For debugging print the list of mounts */
+ write(STDOUT_FILENO, buf, bufsz);
+ write(STDOUT_FILENO, "\n\n", 2);
+#endif
+
+ umount_buffer(buf);
+}
+
+int main(int argc, char **argv, char **envp)
+{
+ pid_t pid;
+ int status;
+ struct rlimit rlim;
+ int clone_flags;
+ char **cmd_argv, *shell_argv[2];
+ char *root = "/", *old = "/mnt";
+ char *label = "none";
+ int i;
+ int tty, tty_force;
+
+ tty = 0;
+ tty_force = 0;
+ clone_flags = SIGCHLD;
+
+ for (i = 1; (i < argc) && (argv[i][0] == '-'); i++) {
+ if (strcmp(argv[i], "--") == 0) {
+ break;
+ }
+ else if (((argc - i) >= 2) && (strcmp(argv[i], "-r") == 0)) {
+ clone_flags |= CLONE_NEWNS;
+ root = argv[i + 1];
+ i++;
+ }
+ else if (((argc - i) >= 2) && (strcmp(argv[i], "-o") == 0)) {
+ old = argv[i + 1];
+ i++;
+ }
+ else if (((argc - i) >= 2) && (strcmp(argv[i], "-l") == 0)) {
+ clone_flags |= CLONE_NEWNS;
+ label = argv[i + 1];
+ i++;
+ }
+ else if (strcmp(argv[i], "-m") == 0) {
+ clone_flags |= CLONE_NEWNS;
+ }
+ else if (strcmp(argv[i], "-h") == 0) {
+ clone_flags |= CLONE_NEWUTS;
+ }
+ else if (strcmp(argv[i], "-i") == 0) {
+ clone_flags |= CLONE_NEWIPC;
+ }
+ else if (strcmp(argv[i], "-n") == 0) {
+ clone_flags |= CLONE_NEWNET;
+ }
+ else if (strcmp(argv[i], "-p") == 0) {
+ clone_flags |= CLONE_NEWPID;
+ }
+ else if (strcmp(argv[i], "-u") == 0) {
+ clone_flags |= CLONE_NEWUID;
+ }
+ else if (strcmp(argv[i], "-d") == 0) {
+ clone_flags |= CLONE_NEWDEV;
+ }
+ else if (strcmp(argv[i], "-t") == 0) {
+ clone_flags |= CLONE_NEWTIME;
+ }
+ else if (strcmp(argv[i], "--tty") == 0) {
+ tty = 1;
+ }
+ else if (strcmp(argv[i], "--tty-force") == 0) {
+ tty = 1; tty_force = 1;
+ }
+ else {
+ die("Bad argument %s\n", argv[i]);
+ }
+ }
+ cmd_argv = argv + i;
+ if (cmd_argv[0] == NULL) {
+ cmd_argv = shell_argv;
+ shell_argv[0] = getenv("SHELL");
+ shell_argv[1] = NULL;
+ }
+ if (cmd_argv[0] == NULL) {
+ die("No command specified\n");
+ }
+#if 1
+ fprintf(stderr, "cmd_argv: %s\n", cmd_argv[0]);
+#endif
+ if (root[0] != '/') {
+ die("root path: '%s' not absolute\n", root);
+ }
+ if (old[0] != '/') {
+ die("old path: '%s' not absolute\n", old);
+ }
+
+#if 0
+ status = getrlimit(RLIMIT_NPROC, &rlim);
+ if (status < 0) {
+ fprintf(stderr, "getrlimit RLIMIT_NPROC failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+ fprintf(stderr, "RLIMIT_NPROC: %llu %llu\n",
+ (unsigned long long)rlim.rlim_cur, (unsigned long long)rlim.rlim_max);
+#endif
+#if 0
+ rlim.rlim_cur = 256;
+ status = setrlimit(RLIMIT_NPROC, &rlim);
+ if (status < 0) {
+ fprintf(stderr, "setrlimit RLIMIT_NPROC %lu %lu failed: %s\n",
+ (unsigned long)rlim.rlim_cur, (unsigned long)rlim.rlim_max,
+ strerror(errno));
+ exit(2);
+ }
+#endif
+ printf("Clone flags: %lx\n", clone_flags);
+ pid = raw_clone(clone_flags, NULL, NULL, NULL, NULL);
+ if (pid < 0) {
+ fprintf(stderr, "clone_failed: pid: %d %d:%s\n",
+ pid, errno, strerror(errno));
+ exit(2);
+ }
+ if (pid == 0) {
+ /* In the child */
+ int result;
+ my_exit = _exit;
+
+ /* FIXME allocate a process inside for controlling the new process space */
+ if (clone_flags & CLONE_NEWPID) {
+ fprintf(stderr, "pid: %d, ppid: %d pgrp: %d sid: %d\n",
+ getpid(), getppid(), getpgid(0), getsid(0));
+ /* If CLONE_NEWPID isn't implemented exit */
+ if (getpid() != 1)
+ die("CLONE_NEWPID not implemented\n");
+ }
+
+ if (clone_flags & CLONE_NEWNS) {
+ struct statfs stfs;
+#if 0
+ if (strcmp(root, "/") != 0) {
+ /* FIXME find a way to remove unreachable filesystems
+ * from the namespace.
+ */
+ result = chdir(root);
+ if (result < 0)
+ die("chdir to '%s' failed: %d:%s\n",
+ root, errno, strerror(errno));
+ /* Convert the current working directory into a mount point */
+ result = mount(".", ".", NULL, MS_BIND | MS_REC, NULL);
+ if (result < 0)
+ die("bind of '%s' failed: %d: %s\n",
+ root, errno, strerror(errno));
+ /* Update the current working directory */
+ result = chdir(root);
+ if (result < 0)
+ die("chdir to '%s' failed: %d:%s\n",
+ ".", errno, strerror(errno));
+ result = mount(".", "/", NULL, MS_MOVE, NULL);
+ if (result < 0)
+ die("mount of '%s' failed: %d:%s\n",
+ root, errno, strerror(errno));
+ result = chroot(".");
+ if (result < 0)
+ die("chroot to '%s' failed: %d:%s\n",
+ root, errno, strerror(errno));
+ }
+#endif
+#if 1
+ if (strcmp(root, "/") != 0) {
+ char put_old[PATH_MAX];
+ result = snprintf(put_old, sizeof(put_old), "%s%s", root, old);
+ if (result >= sizeof(put_old))
+ die("path name to long\n");
+ if (result < 0)
+ die("snprintf failed: %d:%s\n",
+ errno, strerror(errno));
+
+ /* Ensure I have a mount point at the directory I want to export */
+ result = mount(root, root, NULL, MS_BIND | MS_REC, NULL);
+ if (result < 0)
+ die("bind of '%s' failed: %d:%s\n",
+ root, errno, strerror(errno));
+
+ /* Switch the mount points */
+ result = raw_pivot_root(root, put_old);
+ if (result < 0)
+ die("pivot_root('%s', '%s') failed: %d:%s\n",
+ root, put_old, errno, strerror(errno));
+
+ /* Unmount all of the old mounts */
+ result = umount2(old, MNT_DETACH);
+ if (result < 0)
+ die("umount2 of '%s' failed: %d:%s\n",
+ put_old, errno, strerror(errno));
+ }
+#endif
+
+ result = statfs("/proc", &stfs);
+ if ((result == 0) && (stfs.f_type == PROC_SUPER_MAGIC)) {
+ printf ("Umounting proc\n");
+ /* Unmount and remount proc so it reflects the new pid space */
+ result = umount2("/proc", MNT_DETACH);
+ if (result < 0)
+ die("umount failed: %d:%s\n", errno, strerror(errno));
+
+ result = mount(label, "/proc", "proc", 0, NULL);
+ if (result < 0)
+ die("mount failed: %d:%s\n",
+ errno, strerror(errno));
+ }
+ }
+ if (tty) {
+ pid_t sid, pgrp;
+ sid = setsid();
+ if (sid < 0)
+ die("setsid failed: %d:%s\n",
+ errno, strerror(errno));
+ fprintf(stderr, "pid: %d, ppid: %d pgrp: %d sid: %d\n",
+ getpid(), getppid(), getpgid(0), getsid(0));
+
+ result = ioctl(STDIN_FILENO, TIOCSCTTY, tty_force);
+ if (result < 0)
+ die("tiocsctty failed: %d:%s\n",
+ errno, strerror(errno));
+
+ pgrp = tcgetpgrp(STDIN_FILENO);
+
+ fprintf(stderr, "pgrp: %d\n", pgrp);
+
+ fprintf(stderr, "pid: %d, ppid: %d pgrp: %d sid: %d\n",
+ getpid(), getppid(), getpgid(0), getsid(0));
+
+ }
+ result = execve(cmd_argv[0], cmd_argv, envp);
+ die("execve of %s failed: %d:%s\n",
+ cmd_argv[0], errno, strerror(errno));
+ }
+ /* In the parent */
+ fprintf(stderr, "child pid: %d\n", pid);
+ pid = waitpid(pid, &status, 0);
+ fprintf(stderr, "pid: %d exited status: %d\n",
+ pid, status);
+ if (pid < 0) {
+ fprintf(stderr, "waitpid failed: %d %s\n",
+ errno, strerror(errno));
+ exit(9);
+ }
+ if (pid == 0) {
+ fprintf(stderr, "waitpid returned no pid!\n");
+ exit(10);
+ }
+ if (WIFEXITED(status)) {
+ fprintf(stderr, "pid: %d exited: %d\n",
+ pid, WEXITSTATUS(status));
+ }
+ if (WIFSIGNALED(status)) {
+ fprintf(stderr, "pid: %d exited with a uncaught signal: %d %s\n",
+ pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
+ }
+ if (WIFSTOPPED(status)) {
+ fprintf(stderr, "pid: %d stopped with signal: %d\n",
+ pid, WSTOPSIG(status));
+ }
+ return 0;
+}
git://git.onelab.eu / linux-2.6.git / commitdiff