- Use pam_cgroup PAM plugin which will make sure users are placed in right
cgroup at login time and any tasks launch after login, will continue to run
- in user's cgroup. (PAM module is still on TODO list)
+ in user's cgroup.
- Use command line tool "cgexec" to launch the task in right cgroup.
To use a pam plugin which will automatically place the task in right
cgroup upon login.
-- Download pam source tree and apply the patch for pam_cgroup module.
- Build pam_cgroup.so
- ./configure; make
+ make pam_cgroup.so
- Copy pam_cgroup.so to /lib/security/
- Edit /etc/pam.d/su to make use of pam_cgroup.so session module upon
execution of su.
-example: Add following line to the end.
+example:
+ Add following line at the end of /etc/pam.d/su file
+
session optional pam_cgroup.so
- Now launch a shell for a user "xyz" using su and the resulting shell
ex. "su test1"
+Try similar things with other services like sshd.
+
+Note: pam_cgroup.so moves the service providing process in the right cgroup
+ and not the process which will be launched later. Due to parent child
+ relationship, yet to be forked/execed process will launch in right
+ group.
+
+Ex. Lets say user root does "su test1". In this case process "su" is the
+ one providing service (launching a shell) for user "test1". pam_cgroup.so
+ will move process "su" to the user "test1"'s cgroup (Decided by the uid
+ and gid of "test1"). Now once su forks/execs a shell for user test1,
+ final shell is effectively running in the cgroup it should have been
+ running based on /etc/cgrules.conf for user test1.
+
+
Section 4:
----------
To use cgrulesengd which will move a task to right cgroup based on
--- /dev/null
+/*
+ * Copyright RedHat Inc. 2008
+ *
+ * Author: Vivek Goyal <vgoyal@redhat.com>
+ *
+ * Derived from pam_limits.c. Original Copyright notice follows.
+ *
+ * Copyright (c) Cristian Gafton, 1996-1997, <gafton@redhat.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, and the entire permission notice in its entirety,
+ * including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions. (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * End of original copyright notice.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <syslog.h>
+#include <libcgroup.h>
+#include <pwd.h>
+
+/*
+ * Module defines
+ */
+
+#define PAM_SM_SESSION
+
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+#include <security/pam_modutil.h>
+#include <security/pam_ext.h>
+
+/* argument parsing */
+
+#define PAM_DEBUG_ARG 0x0001
+
+static int _pam_parse(const pam_handle_t *pamh, int argc, const char **argv)
+{
+ int ctrl = 0;
+
+ /* step through arguments */
+ for (ctrl = 0; argc-- > 0; ++argv) {
+ if (!strcmp(*argv, "debug"))
+ ctrl |= PAM_DEBUG_ARG;
+ else
+ pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
+ }
+
+ return ctrl;
+}
+
+/* now the session stuff */
+PAM_EXTERN int pam_sm_open_session(pam_handle_t *pamh, int flags,
+ int argc, const char **argv)
+{
+ pid_t pid;
+ int ctrl, ret;
+ char *user_name;
+ struct passwd *pwd;
+
+ D(("called."));
+
+ ctrl = _pam_parse(pamh, argc, argv);
+
+ ret = pam_get_item(pamh, PAM_USER, (void *) &user_name);
+ if (user_name == NULL || ret != PAM_SUCCESS) {
+ pam_syslog(pamh, LOG_ERR, "open_session - error recovering"
+ "username");
+ return PAM_SESSION_ERR;
+ }
+
+ pwd = pam_modutil_getpwnam(pamh, user_name);
+ if (!pwd) {
+ if (ctrl & PAM_DEBUG_ARG)
+ pam_syslog(pamh, LOG_ERR, "open_session username"
+ " '%s' does not exist", user_name);
+ return PAM_SESSION_ERR;
+ }
+
+ D(("user name is %s", user_name));
+
+ /* Initialize libcg */
+ ret = cgroup_init();
+ if (ret) {
+ if (ctrl & PAM_DEBUG_ARG)
+ pam_syslog(pamh, LOG_ERR, "libcgroup initialization"
+ " failed");
+ return PAM_SESSION_ERR;
+ }
+
+ D(("Initialized libcgroup successfuly."));
+
+ /* Determine the pid of the task */
+ pid = getpid();
+
+ /* Note: We are using default gid here. Is there a way to determine
+ * under what egid service will be provided?
+ */
+ ret = cgroup_change_cgroup_uid_gid(pwd->pw_uid, pwd->pw_gid, pid);
+ if (ret) {
+ if (ctrl & PAM_DEBUG_ARG)
+ pam_syslog(pamh, LOG_ERR, "Change of cgroup for process"
+ " with username %s failed.\n", user_name);
+ return PAM_SESSION_ERR;
+ }
+
+ if (ctrl & PAM_DEBUG_ARG)
+ pam_syslog(pamh, LOG_DEBUG, "Changed cgroup for process %d"
+ " with username %s.\n", pid, user_name);
+
+ return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_close_session(pam_handle_t *pamh, int flags, int argc,
+ const char **argv)
+{
+ D(("called pam_cgroup close session"));
+
+ /* nothing to do yet */
+ return PAM_SUCCESS;
+}
projects / thirdparty / libcgroup.git / commitdiff
