-/*
- * Marc E. Fiuczynski <mef@cs.princeton.edu>
- *
- * Copyright (c) 2004 The Trustees of Princeton University (Trustees).
- *
- * vsh is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * vsh 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 for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Poptop; see the file COPYING. If not, write to the Free
- * Software Foundation, 59 Temple Place - Suite 330, Boston, MA
- * 02111-1307, USA.
- */
+/* Version 2 of vsh. Basically a wrapper around 'vserver <slice name> enter.' */
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <limits.h>
-#include <pwd.h>
#include <unistd.h>
-#include <syscall.h>
-#include <sys/syscall.h>
-#include <asm/unistd.h>
-#include <sys/mount.h>
+#include <pwd.h>
+#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
-#include <sys/resource.h>
-#include <fcntl.h>
-#include <ctype.h>
-#include <stdarg.h>
-
-//--------------------------------------------------------------------
-#include <vserver.h>
-#include "planetlab.h"
-
-/* Change to root:root (before entering new context) */
-static int setuidgid_root()
-{
- if (setgid(0) < 0) {
- PERROR("setgid(0)");
- return -1;
- }
- if (setuid(0) < 0) {
- PERROR("setuid(0)");
- return -1;
- }
- return 0;
-}
-
-static void compute_new_root(char *base, char **root, const struct passwd *pwd)
-{
- int root_len;
-
- root_len =
- strlen(base) + strlen("/") +
- strlen(pwd->pw_name) + NULLBYTE_SIZE;
- (*root) = (char *)malloc(root_len);
- if ((*root) == NULL) {
- PERROR("malloc(%d)", root_len);
- exit(1);
- }
-
- sprintf((*root), "%s/%s", base, pwd->pw_name);
- (*root)[root_len - 1] = '\0';
-}
-
-static int sandbox_chroot(const struct passwd *pwd)
-{
- char *sandbox_root = NULL;
-
- compute_new_root(DEFAULT_VSERVERDIR,&sandbox_root, pwd);
- if (chroot(sandbox_root) < 0) {
- PERROR("chroot(%s)", sandbox_root);
- exit(1);
- }
- if (chdir("/") < 0) {
- PERROR("chdir(/)");
- exit(1);
- }
- return 0;
-}
-
-static int sandbox_processes(xid_t ctx, const char *context, const struct passwd *pwd)
-{
-#ifdef CONFIG_VSERVER_LEGACY
- int flags;
-
- flags = 0;
- flags |= 1; /* VX_INFO_LOCK -- cannot request a new vx_id */
- /* flags |= 4; VX_INFO_NPROC -- limit number of procs in a context */
-
- (void) vc_new_s_context(ctx, 0, flags);
-
- /* use legacy dirty hack for capremove */
- if (vc_new_s_context(VC_SAMECTX, vc_get_insecurebcaps(), flags) == VC_NOCTX) {
- PERROR("vc_new_s_context(%u, 0x%16llx, 0x%08x)",
- VC_SAMECTX, vc_get_insecurebcaps(), flags);
- exit(1);
- }
-#else
- int ctx_is_new;
- struct sliver_resources slr;
- char hostname[HOST_NAME_MAX+1];
- pl_get_limits(context,&slr);
-
- if (gethostname(hostname, sizeof hostname) == -1)
- {
- PERROR("gethostname(...)");
- exit(1);
- }
-
- /* check whether the slice has been suspended */
- if (slr.vs_cpu==0)
- {
- fprintf(stderr, "*** %s: %s has zero cpu resources and presumably it has been disabled/suspended ***\n", hostname, context);
- exit(0);
- }
-
- (void) (sandbox_chroot(pwd));
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
- if ((ctx_is_new = pl_chcontext(ctx, ~vc_get_insecurebcaps(),&slr)) < 0)
- {
- PERROR("pl_chcontext(%u)", ctx);
- exit(1);
- }
- if (ctx_is_new)
- {
- fprintf(stderr, " *** %s: %s has not been started yet, please check back later ***\n", hostname, context);
- exit(1);
- }
+#define VSH_PATH "/usr/sbin/vsh"
+#ifndef PATH_MAX
+#define PATH_MAX 4096
#endif
- return 0;
-}
+#define VSERVER_PATH "/usr/sbin/vserver"
-void runas_slice_user(struct passwd *pwd)
+char* get_current_username (unsigned int uid)
{
- char *username = pwd->pw_name;
- char *home_env, *logname_env, *mail_env, *shell_env, *user_env;
- int home_len, logname_len, mail_len, shell_len, user_len;
- static char *envp[10];
-
- if (setgid(pwd->pw_gid) < 0) {
- PERROR("setgid(%d)", pwd->pw_gid);
- exit(1);
- }
-
- if (setuid(pwd->pw_uid) < 0) {
- PERROR("setuid(%d)", pwd->pw_uid);
- exit(1);
- }
-
- if (chdir(pwd->pw_dir) < 0) {
- PERROR("chdir(%s)", pwd->pw_dir);
- exit(1);
- }
-
- home_len = strlen("HOME=") + strlen(pwd->pw_dir) + NULLBYTE_SIZE;
- logname_len = strlen("LOGNAME=") + strlen(username) + NULLBYTE_SIZE;
- mail_len = strlen("MAIL=/var/spool/mail/") + strlen(username)
- + NULLBYTE_SIZE;
- shell_len = strlen("SHELL=") + strlen(pwd->pw_shell) + NULLBYTE_SIZE;
- user_len = strlen("USER=") + strlen(username) + NULLBYTE_SIZE;
-
- home_env = (char *)malloc(home_len);
- logname_env = (char *)malloc(logname_len);
- mail_env = (char *)malloc(mail_len);
- shell_env = (char *)malloc(shell_len);
- user_env = (char *)malloc(user_len);
-
- if ((home_env == NULL) ||
- (logname_env == NULL) ||
- (mail_env == NULL) ||
- (shell_env == NULL) ||
- (user_env == NULL)) {
- PERROR("malloc");
- exit(1);
- }
-
- sprintf(home_env, "HOME=%s", pwd->pw_dir);
- sprintf(logname_env, "LOGNAME=%s", username);
- sprintf(mail_env, "MAIL=/var/spool/mail/%s", username);
- sprintf(shell_env, "SHELL=%s", pwd->pw_shell);
- sprintf(user_env, "USER=%s", username);
-
- home_env[home_len - 1] = '\0';
- logname_env[logname_len - 1] = '\0';
- mail_env[mail_len - 1] = '\0';
- shell_env[shell_len - 1] = '\0';
- user_env[user_len - 1] = '\0';
-
- envp[0] = home_env;
- envp[1] = logname_env;
- envp[2] = mail_env;
- envp[3] = shell_env;
- envp[4] = user_env;
- envp[5] = 0;
+ struct passwd *passwd_entry;
+ if ((passwd_entry = getpwuid(uid)) == NULL) {
+ fprintf(stderr, "Could not look up user record for %d\n", uid);
+ return NULL;
+ }
- if ((putenv(home_env) < 0) ||
- (putenv(logname_env) < 0) ||
- (putenv(mail_env) < 0) ||
- (putenv(shell_env) < 0) ||
- (putenv(user_env) < 0)) {
- PERROR("vserver: putenv error ");
- exit(1);
- }
+ return (strdup(passwd_entry->pw_name));
}
-void slice_enter(struct passwd *pwd)
-{
- if (setuidgid_root() < 0) { /* For chroot, new_s_context */
- fprintf(stderr, "vsh: Could not become root, check that SUID flag is set on binary\n");
- exit(2);
- }
-
-#ifdef CONFIG_VSERVER_LEGACY
- (void) (sandbox_chroot(pwd));
-#endif
+char **extend_argv(int argc, char **argv, int num_extra_args) {
+ int argc2, i;
+ char **argv2;
- if (sandbox_processes((xid_t) pwd->pw_uid, pwd->pw_name, pwd) < 0) {
- fprintf(stderr, "vsh: Could not change context to %d\n", pwd->pw_uid);
- exit(2);
- }
-}
+ argc2 = argc + num_extra_args;
+ argv2 = (char **) malloc((argc2 + 1) * sizeof(char *));
-//--------------------------------------------------------------------
+ if (!argv2)
+ return (char **) NULL;
-#define DEFAULT_SHELL "/bin/sh"
+ for (i=0; i<argc; i++) {
+ argv2[i+num_extra_args]=strdup(argv[i]);
+ }
+ argv2[argc2]=NULL;
-/* Exit statuses for programs like 'env' that exec other programs.
- EXIT_FAILURE might not be 1, so use EXIT_FAIL in such programs. */
-enum
-{
- EXIT_CANNOT_INVOKE = 126,
- EXIT_ENOENT = 127
-};
+ return argv2;
+}
-int main(int argc, char **argv)
+void associate_vserver_cgroup(char *slice_name, int pid)
{
- struct passwd pwdd, *result, *prechroot, *postchroot = &pwdd;
- char *context, *username, *shell, *pwdBuffer;
- long pwdBuffer_len;
- uid_t uid;
- int index, i;
+ char cgroup_dir[4096], fn[4096];
+ struct stat st;
+ int result;
+ FILE *f;
- if (argv[0][0]=='-')
- index = 1;
- else
- index = 0;
+ sprintf(cgroup_dir, "/dev/cgroup/%s", slice_name);
- uid = getuid();
- if ((prechroot = getpwuid(uid)) == NULL) {
- PERROR("getpwuid(%d)", uid);
- exit(1);
+ result = stat(cgroup_dir, &st);
+ if (result != 0) {
+ // doesn't exist
+ return;
}
- context = (char*)strdup(prechroot->pw_name);
- if (!context) {
- PERROR("strdup");
- exit(2);
+ if (!S_ISDIR(st.st_mode)) {
+ // not a directory
+ return;
}
- /* enter vserver "context" */
- slice_enter(prechroot);
-
- /* Get the /etc/passwd entry for this user, this time inside
- * the chroot.
+ /* Write the pid to the cgroup tasks file, so the SSH process is associated
+ * with the correct cgroup
*/
- username = context;
- pwdBuffer_len = sysconf(_SC_GETPW_R_SIZE_MAX);
- if (pwdBuffer_len == -1) {
- PERROR("sysconf(_SC_GETPW_R_SIZE_MAX");
- exit(1);
+ sprintf(fn, "%s/tasks", cgroup_dir);
+ f = fopen(fn, "wt");
+ if (f==NULL) {
+ // failed to open
+ return;
}
- pwdBuffer = (char*)malloc(pwdBuffer_len);
- if (pwdBuffer == NULL) {
- PERROR("malloc(%d)", pwdBuffer_len);
- exit(1);
- }
-
- errno = 0;
- if ((getpwnam_r(username,postchroot,pwdBuffer,pwdBuffer_len, &result) != 0) ||
- (errno != 0) || result != postchroot) {
- PERROR("getpwnam_r(%s)", username);
- exit(1);
- }
-
- /* Now run as username in this context. Note that for PlanetLab's
- vserver configuration the context name also happens to be the
- "default" username within the vserver context.
- */
- runas_slice_user(postchroot);
- /* Make sure pw->pw_shell is non-NULL.*/
- if (postchroot->pw_shell == NULL || postchroot->pw_shell[0] == '\0') {
- postchroot->pw_shell = (char *) DEFAULT_SHELL;
- }
+ fprintf(f, "%d\n", pid);
+ fclose(f);
+}
- shell = (char *)strdup(postchroot->pw_shell);
- if (!shell) {
- PERROR("strdup");
- exit(2);
- }
+#define NUM_VSERVER_EXEC_ARGS 5
- /* Check whether 'su' or 'sshd' invoked us as a login shell or
- not; did this above when testing argv[0]=='-'.
- */
- argv[0] = shell;
- if (index == 1) {
- char **args;
- args = (char**)malloc(sizeof(char*)*(argc+2));
- if (!args) {
- PERROR("malloc(%d)", sizeof(char*)*(argc+2));
- exit(1);
- }
- args[0] = argv[0];
- args[1] = "-l";
- for(i=1;i<argc+1;i++) {
- args[i+1] = argv[i];
- }
- argv = args;
- }
- (void) execvp(shell,argv);
- {
- int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
- exit (exit_status);
+int main(int argc, char **argv, char **envp)
+{
+ char *slice_name;
+ char **argv2;
+ int argc2;
+ char slice_id_str[256];
+ unsigned int slice_xid;
+
+ slice_xid = getuid();
+ slice_name = get_current_username(slice_xid);
+ if (!slice_name) {
+ fprintf(stderr,"Could not look up slice name\n");
+ goto out_exception;
}
- return 0; /* shutup compiler */
+ associate_vserver_cgroup(slice_name, getpid());
+
+ argv2 = extend_argv(argc, argv, NUM_VSERVER_EXEC_ARGS);
+ if (!argv2) goto out_exception;
+
+
+ // Populate arguments
+ snprintf(slice_id_str, 255, "%u", slice_xid);
+ argv2[0] = strdup(VSERVER_PATH);
+ argv2[1] = strdup(slice_name);
+ argv2[2] = strdup("exec");
+ argv2[3] = strdup("/bin/su");
+ argv2[4] = strdup("-");
+ argv2[5] = strdup(slice_name);
+
+ if (setuid(geteuid())) goto out_exception;
+
+ execve(VSERVER_PATH, argv2, envp);
+
+out_exception:
+ printf("%s\n", strerror(errno));
+ return errno;
}
git://git.onelab.eu / util-vserver-pl.git / commitdiff