--- /dev/null
+/*
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include "compat.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <pwd.h>
+#include <unistd.h>
+#include <syscall.h>
+#include <sys/syscall.h>
+#include <asm/unistd.h>
+#include <sys/mount.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"
+
+#undef CONFIG_VSERVER_LEGACY
+
+/* Null byte made explicit */
+#define NULLBYTE_SIZE 1
+
+/* Base for all vserver roots for chroot */
+#define VSERVER_ROOT_BASE "/vservers"
+
+static int
+_PERROR(const char *format, char *file, int line, int _errno, ...)
+{
+ va_list ap;
+
+ va_start(ap, _errno);
+ fprintf(stderr, "%s:%d: ", file, line);
+ vfprintf(stderr, format, ap);
+ if (_errno)
+ fprintf(stderr, ": %s (%d)", strerror(_errno), _errno);
+ fputs("\n", stderr);
+ fflush(stderr);
+
+ return _errno;
+}
+
+#define PERROR(format, args...) _PERROR(format, __FILE__, __LINE__, errno, ## args)
+
+/* 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, uid_t uid)
+{
+ int root_len;
+ struct passwd *pwd;
+
+ if ((pwd = getpwuid(uid)) == NULL) {
+ PERROR("getpwuid(%d)", uid);
+ exit(1);
+ }
+
+ 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';
+}
+
+/* Example: sandbox_root = /vservers/bnc, relpath = /proc/1 */
+static int sandbox_file_exists(char *sandbox_root, char *relpath)
+{
+ struct stat stat_buf;
+ char *file;
+ int len, exists = 0;
+
+ len = strlen(sandbox_root) + strlen(relpath) + NULLBYTE_SIZE;
+ if ((file = (char *)malloc(len)) == NULL) {
+ PERROR("malloc(%d)", len);
+ exit(1);
+ }
+ sprintf(file, "%s%s", sandbox_root, relpath);
+ file[len - 1] = '\0';
+ if (stat(file, &stat_buf) == 0) {
+ exists = 1;
+ }
+
+
+ free(file);
+ return exists;
+}
+
+static int proc_mounted(char *sandbox_root)
+{
+ return sandbox_file_exists(sandbox_root, "/proc/1");
+}
+
+static int devpts_mounted(char *sandbox_root)
+{
+ return sandbox_file_exists(sandbox_root, "/dev/pts/0");
+}
+
+static void mount_proc(char *sandbox_root)
+{
+ char *source = "/proc";
+ char *target;
+ int len;
+
+ len = strlen(sandbox_root) + strlen("/") + strlen("proc") + NULLBYTE_SIZE;
+ if ((target = (char *)malloc(len)) == NULL) {
+ PERROR("malloc(%d)", len);
+ exit(1);
+ }
+
+ sprintf(target, "%s/proc", sandbox_root);
+ target[len - 1] = '\0';
+ if (!proc_mounted(sandbox_root))
+ mount(source, target, "proc", MS_BIND | MS_RDONLY, NULL);
+
+ free(target);
+}
+
+static void mount_devpts(char *sandbox_root)
+{
+ char *source = "/dev/pts";
+ char *target;
+ int len;
+
+ len = strlen(sandbox_root) + strlen("/") + strlen("dev/pts") + NULLBYTE_SIZE;
+ if ((target = (char *)malloc(len)) == NULL) {
+ PERROR("malloc(%d)", len);
+ exit(1);
+ }
+
+ sprintf(target, "%s/dev/pts", sandbox_root);
+ target[len - 1] = '\0';
+ if (!devpts_mounted(sandbox_root))
+ mount(source, target, "devpts", 0, NULL);
+
+ free(target);
+}
+
+static int sandbox_chroot(uid_t uid)
+{
+ char *sandbox_root = NULL;
+
+ compute_new_root(VSERVER_ROOT_BASE,&sandbox_root, uid);
+ mount_proc(sandbox_root);
+ mount_devpts(sandbox_root);
+ if (chroot(sandbox_root) < 0) {
+ PERROR("chroot(%s)", sandbox_root);
+ exit(1);
+ }
+ if (chdir("/") < 0) {
+ PERROR("chdir(/)");
+ exit(1);
+ }
+ return 0;
+}
+
+#define WHITESPACE(buffer,index,len) \
+ while(isspace((int)buffer[index])) \
+ if (index < len) index++; else goto out;
+
+struct resources {
+ char *name;
+ unsigned long long *limit;
+};
+
+#define VSERVERCONF "/etc/vservers/"
+static void get_limits(char *context, struct resources *list){
+ FILE *fb;
+ size_t len = strlen(VSERVERCONF) + strlen(context) + strlen(".conf") + NULLBYTE_SIZE;
+ char *conf = (char *)malloc(len);
+ struct resources *r;
+
+ sprintf(conf, "%s%s.conf", VSERVERCONF, context);
+
+ /* open the conf file for reading */
+ fb = fopen(conf,"r");
+ if (fb != NULL) {
+ size_t index;
+ char *buffer = malloc(1000);
+ char *p;
+
+ /* the conf file exist */
+ while((p=fgets(buffer,1000-1,fb))!=NULL) {
+ index = 0;
+ len = strnlen(buffer,1000);
+ WHITESPACE(buffer,index,len);
+ if (buffer[index] == '#')
+ continue;
+
+ for (r=list; r->name; r++)
+ if ((p=strstr(&buffer[index],r->name))!=NULL) {
+ /* adjust index into buffer */
+ index+= (p-&buffer[index])+strlen(r->name);
+
+ /* skip over whitespace */
+ WHITESPACE(buffer,index,len);
+
+ /* expecting to see = sign */
+ if (buffer[index++]!='=') goto out;
+
+ /* skip over whitespace */
+ WHITESPACE(buffer,index,len);
+
+ /* expecting to see a digit for number */
+ if (!isdigit((int)buffer[index])) goto out;
+
+ *r->limit = atoi(&buffer[index]);
+ break;
+ }
+ }
+ out:
+ free(buffer);
+ } else {
+ fprintf(stderr,"cannot open %s\n",conf);
+ }
+ free(conf);
+}
+
+
+static int sandbox_processes(xid_t ctx, char *context)
+{
+#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%16ullx, 0x%08x)",
+ VC_SAMECTX, vc_get_insecurebcaps(), flags);
+ exit(1);
+ }
+#else
+ rspec_t rspec;
+ unsigned long long cpu = VC_LIM_KEEP;
+ unsigned long long mem = VC_LIM_KEEP;
+ unsigned long long task = VC_LIM_KEEP;
+ unsigned long long cpuguaranteed = 0;
+ struct resources list[] =
+ {{"MEMLIMIT", &mem},
+ {"CPULIMIT", &cpu},
+ {"CPUGUARANTEED", &cpuguaranteed},
+ {"TASKLIMIT", &task},
+ {0,0}};
+
+ get_limits(context,list);
+ (void) (sandbox_chroot(ctx));
+
+ rspec.cpu_share = cpu;
+ rspec.cpu_sched_flags = (VC_VXF_SCHED_HARD |
+ (cpuguaranteed ? 0 : VC_VXF_SCHED_SHARE));
+ rspec.mem_limit = mem;
+ rspec.task_limit = task;
+ if (pl_chcontext(ctx, 0, ~vc_get_insecurebcaps(), &rspec))
+ {
+ PERROR("pl_chcontext(%u)", ctx);
+ exit(1);
+ }
+#endif
+ return 0;
+}
+
+
+void runas_slice_user(char *username)
+{
+ struct passwd pwdd, *pwd = &pwdd, *result;
+ char *pwdBuffer;
+ char *home_env, *logname_env, *mail_env, *shell_env, *user_env;
+ int home_len, logname_len, mail_len, shell_len, user_len;
+ long pwdBuffer_len;
+ static char *envp[10];
+
+
+ pwdBuffer_len = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (pwdBuffer_len == -1) {
+ PERROR("sysconf(_SC_GETPW_R_SIZE_MAX)");
+ exit(1);
+ }
+
+ pwdBuffer = (char*)malloc(pwdBuffer_len);
+ if (pwdBuffer == NULL) {
+ PERROR("malloc(%d)", pwdBuffer_len);
+ exit(1);
+ }
+
+ errno = 0;
+ if ((getpwnam_r(username,pwd,pwdBuffer,pwdBuffer_len, &result) != 0) || (errno != 0)) {
+ PERROR("getpwnam_r(%s)", username);
+ exit(1);
+ }
+
+ 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;
+
+ 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);
+ }
+}
+
+void slice_enter(char *context)
+{
+ struct passwd pwdd, *pwd = &pwdd, *result;
+ char *pwdBuffer;
+ long pwdBuffer_len;
+ uid_t uid;
+
+ pwdBuffer_len = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (pwdBuffer_len == -1) {
+ PERROR("sysconf(_SC_GETPW_R_SIZE_MAX)");
+ exit(1);
+ }
+
+ pwdBuffer = (char*)malloc(pwdBuffer_len);
+ if (pwdBuffer == NULL) {
+ PERROR("malloc(%d)", pwdBuffer_len);
+ exit(1);
+ }
+
+ errno = 0;
+ if ((getpwnam_r(context,pwd,pwdBuffer,pwdBuffer_len, &result) != 0) || (errno != 0)) {
+ PERROR("getpwnam_r(%s)", context);
+ exit(2);
+ }
+ uid = pwd->pw_uid;
+
+ 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(uid));
+#endif
+
+ if (sandbox_processes((xid_t) uid, context) < 0) {
+ fprintf(stderr, "vsh: Could not change context to %d\n", uid);
+ exit(2);
+ }
+}
+
+//--------------------------------------------------------------------
+
+#define DEFAULT_SHELL "/bin/sh"
+
+/* 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
+};
+
+int main(int argc, char **argv)
+{
+ struct passwd pwdd, *pwd = &pwdd, *result;
+ char *context, *username, *shell, *pwdBuffer;
+ long pwdBuffer_len;
+ uid_t uid;
+ int index, i;
+
+ if (argv[0][0]=='-')
+ index = 1;
+ else
+ index = 0;
+
+ uid = getuid();
+ if ((pwd = getpwuid(uid)) == NULL) {
+ PERROR("getpwuid(%d)", uid);
+ exit(1);
+ }
+
+ context = (char*)strdup(pwd->pw_name);
+ if (!context) {
+ PERROR("strdup");
+ exit(2);
+ }
+
+ /* enter vserver "context" */
+ slice_enter(context);
+
+ /* 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.
+ */
+ username = context;
+ runas_slice_user(username);
+
+ /* With the uid/gid appropriately set. Let's figure out what the
+ * shell in the vserver's /etc/passwd is for the given username.
+ */
+
+ pwdBuffer_len = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (pwdBuffer_len == -1) {
+ PERROR("sysconf(_SC_GETPW_R_SIZE_MAX");
+ exit(1);
+ }
+ pwdBuffer = (char*)malloc(pwdBuffer_len);
+ if (pwdBuffer == NULL) {
+ PERROR("malloc(%d)", pwdBuffer_len);
+ exit(1);
+ }
+
+ errno = 0;
+ if ((getpwnam_r(username,pwd,pwdBuffer,pwdBuffer_len, &result) != 0) || (errno != 0)) {
+ PERROR("getpwnam_r(%s)", username);
+ exit(1);
+ }
+
+ /* Make sure pw->pw_shell is non-NULL.*/
+ if (pwd->pw_shell == NULL || pwd->pw_shell[0] == '\0') {
+ pwd->pw_shell = (char *) DEFAULT_SHELL;
+ }
+
+ shell = (char *)strdup(pwd->pw_shell);
+ if (!shell) {
+ PERROR("strdup");
+ exit(2);
+ }
+
+ /* 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);
+ }
+
+ return 0; /* shutup compiler */
+}
git://git.onelab.eu / util-vserver.git / blobdiff