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Subject[PATCH] BSD Secure Levels LSM (1/3)
This it the BSD Secure Levels LSM.  This patch includes the seclvl
module with changes to Kconfig and Makefile.

In the patch submitted a little while back, if mod_reg_security()
failed, that return code was not being returned from seclvl_init().
That is fixed in this patch. It applies cleanly to 2.6.8.1 and has
been tested on xSeries, pSeries, and zSeries. Please apply.

Signed-off-by: Michael A. Halcrow <mike@halcrow.us>

Mike
--- linux-2.6.8-rc3/security/Kconfig 2004-06-16 00:19:42.000000000 -0500
+++ linux-2.6.8-rc3_seclvl/security/Kconfig 2004-08-30 08:35:37.000000000 -0500
@@ -44,6 +44,23 @@

If you are unsure how to answer this question, answer N.

+config SECURITY_SECLVL
+ tristate "BSD Secure Levels"
+ depends on SECURITY
+ select CRYPTO_SHA1
+ help
+ Implements BSD Secure Levels as an LSM. See
+ Documentation/seclvl.txt for instructions on how to use this
+ module.
+
+ If you are unsure how to answer this question, answer N.
+
+config SECURITY_STACKER
+ tristate "Stacker"
+ depends on SECURITY
+ help
+ Implements LSM stacker.
+
source security/selinux/Kconfig

endmenu
--- linux-2.6.8-rc3/security/Makefile 2004-06-16 00:19:43.000000000 -0500
+++ linux-2.6.8-rc3_seclvl/security/Makefile 2004-08-30 08:35:02.000000000 -0500
@@ -15,3 +15,5 @@
obj-$(CONFIG_SECURITY_SELINUX) += selinux/built-in.o
obj-$(CONFIG_SECURITY_CAPABILITIES) += commoncap.o capability.o
obj-$(CONFIG_SECURITY_ROOTPLUG) += commoncap.o root_plug.o
+obj-$(CONFIG_SECURITY_SECLVL) += seclvl.o
+obj-$(CONFIG_SECURITY_STACKER) += stacker.o
--- linux-2.6.8-rc3/security/seclvl.c 1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.8-rc3_seclvl/security/seclvl.c 2004-08-30 09:16:01.000000000 -0500
@@ -0,0 +1,754 @@
+/**
+ * BSD Secure Levels LSM
+ *
+ * Maintainers:
+ * Michael A. Halcrow <mike@halcrow.us>
+ * Serge Hallyn <hallyn@cs.wm.edu>
+ *
+ * Copyright (c) 2001 WireX Communications, Inc <chris@wirex.com>
+ * Copyright (c) 2001 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (c) 2002 International Business Machines <robb@austin.ibm.com>
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * Potential future enhancements:
+ * - Export a kill_seclvl function to the rest of the kernel to allow
+ * other modules to disable or change the seclvl (i.e., rootplug
+ * could reduce the seclvl).
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/security.h>
+#include <linux/netlink.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/capability.h>
+#include <linux/time.h>
+#include <linux/proc_fs.h>
+#include <linux/kobject.h>
+#include <linux/crypto.h>
+#include <asm/scatterlist.h>
+#include <linux/gfp.h>
+#include <linux/sysfs.h>
+
+#define SHA1_DIGEST_SIZE 20
+
+/**
+ * Module parameter that defines the initial secure level.
+ *
+ * When built as a module, it defaults to seclvl 1, which is the
+ * behavior of BSD secure levels. Note that this default behavior
+ * wrecks havoc on a machine when the seclvl module is compiled into
+ * the kernel. In that case, we default to seclvl 0.
+ */
+#ifdef CONFIG_SECURITY_SECLVL_MODULE
+static int initlvl = 1;
+#else
+static int initlvl;
+#endif
+module_param(initlvl, int, 0);
+MODULE_PARM_DESC(initlvl, "Initial secure level (defaults to 1)");
+
+/* Module parameter that defines the verbosity level */
+static int verbosity;
+module_param(verbosity, int, 0);
+MODULE_PARM_DESC(verbosity, "Initial verbosity level (0 or 1; defaults to "
+ "0, which is Quiet)");
+
+/**
+ * Optional password which can be passed in to bring seclvl to 0
+ * (i.e., for halt/reboot). Defaults to NULL (the passwd attribute
+ * file will not be registered in sysfs).
+ *
+ * This gets converted to its SHA1 hash when stored. It's probably
+ * not a good idea to use this parameter when loading seclvl from a
+ * script; use sha1_passwd instead.
+ */
+
+#define MAX_PASSWD_SIZE 32
+static char passwd[MAX_PASSWD_SIZE];
+module_param_string(passwd, passwd, sizeof(passwd), 0);
+MODULE_PARM_DESC(passwd,
+ "Plaintext of password that sets seclvl=0 when written to "
+ "(sysfs mount point)/seclvl/passwd\n");
+
+/**
+ * SHA1 hashed version of the optional password which can be passed in
+ * to bring seclvl to 0 (i.e., for halt/reboot). Must be in
+ * hexadecimal format (40 characters). Defaults to NULL (the passwd
+ * attribute file will not be registered in sysfs).
+ *
+ * Use the sha1sum utility to generate the SHA1 hash of a password:
+ *
+ * echo -n "secret" | sha1sum
+ */
+#define MAX_SHA1_PASSWD 41
+static char sha1_passwd[MAX_SHA1_PASSWD];
+module_param_string(sha1_passwd, sha1_passwd, sizeof(sha1_passwd), 0);
+MODULE_PARM_DESC(sha1_passwd,
+ "SHA1 hash (40 hexadecimal characters) of password that "
+ "sets seclvl=0 when plaintext password is written to "
+ "(sysfs mount point)/seclvl/passwd\n");
+
+static int hideHash = 1;
+module_param(hideHash, int, 0);
+MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs "
+ "will return the SHA1-hashed value of the password that "
+ "lowers the secure level to 0.\n");
+
+#define MY_NAME "seclvl"
+
+/**
+ * This time-limits log writes to one per second.
+ */
+#define seclvl_printk(verb, type, fmt, arg...) \
+ do { \
+ if (verbosity >= verb) { \
+ static unsigned long _prior; \
+ unsigned long _now = jiffies; \
+ if ((_now - _prior) > HZ) { \
+ printk(type "%s: %s: " fmt, \
+ MY_NAME, __FUNCTION__, \
+ ## arg); \
+ _prior = _now; \
+ } \
+ } \
+ } while (0)
+
+/**
+ * kobject stuff
+ */
+
+struct subsystem seclvl_subsys;
+
+struct seclvl_obj {
+ char *name;
+ struct list_head slot_list;
+ struct kobject kobj;
+};
+
+/**
+ * There is a seclvl_attribute struct for each file in sysfs.
+ *
+ * In our case, we have one of these structs for "passwd" and another
+ * for "seclvl".
+ */
+struct seclvl_attribute {
+ struct attribute attr;
+ ssize_t(*show) (struct seclvl_obj *, char *);
+ ssize_t(*store) (struct seclvl_obj *, const char *, size_t);
+};
+
+/**
+ * When this function is called, one of the files in sysfs is being
+ * written to. attribute->store is a function pointer to whatever the
+ * struct seclvl_attribute store function pointer points to. It is
+ * unique for "passwd" and "seclvl".
+ */
+static ssize_t
+seclvl_attr_store(struct kobject *kobj,
+ struct attribute *attr, const char *buf, size_t len)
+{
+ struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
+ struct seclvl_attribute *attribute =
+ container_of(attr, struct seclvl_attribute, attr);
+ return (attribute->store ? attribute->store(obj, buf, len) : 0);
+}
+
+static ssize_t
+seclvl_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+ struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
+ struct seclvl_attribute *attribute =
+ container_of(attr, struct seclvl_attribute, attr);
+ return (attribute->show ? attribute->show(obj, buf) : 0);
+}
+
+/**
+ * Callback function pointers for show and store
+ */
+struct sysfs_ops seclvlfs_sysfs_ops = {
+ .show = seclvl_attr_show,
+ .store = seclvl_attr_store,
+};
+
+static struct kobj_type seclvl_ktype = {
+ .sysfs_ops = &seclvlfs_sysfs_ops
+};
+
+decl_subsys(seclvl, &seclvl_ktype, NULL);
+
+/**
+ * The actual security level. Ranges between -1 and 2 inclusive.
+ */
+static int seclvl;
+
+/**
+ * flag to keep track of how we were registered
+ */
+static int secondary;
+
+/**
+ * Verifies that the requested secure level is valid, given the current
+ * secure level.
+ */
+static int seclvl_sanity(int reqlvl)
+{
+ if ((reqlvl < -1) || (reqlvl > 2)) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to set seclvl out of "
+ "range: [%d]\n", reqlvl);
+ return -EINVAL;
+ }
+ if ((seclvl == 0) && (reqlvl == -1))
+ return 0;
+ if (reqlvl < seclvl) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to lower seclvl to "
+ "[%d]\n", reqlvl);
+ return -EPERM;
+ }
+ return 0;
+}
+
+/**
+ * Called whenever the user reads the sysfs handle to this kernel
+ * object
+ */
+static ssize_t seclvl_read_file(struct seclvl_obj *obj, char *buff)
+{
+ return snprintf(buff, PAGE_SIZE, "%d\n", seclvl);
+}
+
+/**
+ * security level advancement rules:
+ * Valid levels are -1 through 2, inclusive.
+ * From -1, stuck. [ in case compiled into kernel ]
+ * From 0 or above, can only increment.
+ */
+static int do_seclvl_advance(int newlvl)
+{
+ if (newlvl <= seclvl) {
+ seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
+ "[%d]\n", newlvl);
+ return -EINVAL;
+ }
+ if (newlvl > 2) {
+ seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
+ "[%d]\n", newlvl);
+ return -EINVAL;
+ }
+ if (seclvl == -1) {
+ seclvl_printk(1, KERN_WARNING, "Not allowed to advance to "
+ "seclvl [%d]\n", seclvl);
+ return -EPERM;
+ }
+ seclvl = newlvl;
+ return 0;
+}
+
+/**
+ * Called whenever the user writes to the sysfs handle to this kernel
+ * object (seclvl/seclvl). It expects a single-digit number.
+ */
+static ssize_t
+seclvl_write_file(struct seclvl_obj *obj, const char *buff, size_t count)
+{
+ unsigned long val;
+ if (count > 2 || (count == 2 && buff[1] != '\n')) {
+ seclvl_printk(1, KERN_WARNING, "Invalid value passed to "
+ "seclvl: [%s]\n", buff);
+ return -EINVAL;
+ }
+ val = buff[0] - 48;
+ if (seclvl_sanity(val)) {
+ seclvl_printk(1, KERN_WARNING, "Illegal secure level "
+ "requested: [%d]\n", (int)val);
+ return -EPERM;
+ }
+ if (do_seclvl_advance(val)) {
+ seclvl_printk(0, KERN_ERR, "Failure advancing security level "
+ "to %lu\n", val);
+ }
+ return count;
+}
+
+/* Generate sysfs_attr_seclvl */
+struct seclvl_attribute sysfs_attr_seclvl =
+__ATTR(seclvl, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_file,
+ seclvl_write_file);
+
+static unsigned char hashedPassword[SHA1_DIGEST_SIZE];
+
+/**
+ * Called whenever the user reads the sysfs passwd handle.
+ */
+static ssize_t seclvl_read_passwd(struct seclvl_obj *obj, char *buff)
+{
+ /* So just how good *is* your password? :-) */
+ char tmp[3];
+ int i = 0;
+ buff[0] = '\0';
+ if (hideHash) {
+ /* Security through obscurity */
+ return 0;
+ }
+ while (i < SHA1_DIGEST_SIZE) {
+ snprintf(tmp, 3, "%02x", hashedPassword[i]);
+ strncat(buff, tmp, 2);
+ i++;
+ }
+ strcat(buff, "\n");
+ return ((SHA1_DIGEST_SIZE * 2) + 1);
+}
+
+/**
+ * Converts a block of plaintext of into its SHA1 hashed value.
+ *
+ * It would be nice if crypto had a wrapper to do this for us linear
+ * people...
+ */
+static int
+plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len)
+{
+ char *pgVirtAddr;
+ struct crypto_tfm *tfm;
+ struct scatterlist sg[1];
+ if (len > PAGE_SIZE) {
+ seclvl_printk(0, KERN_ERR, "Plaintext password too large (%d "
+ "characters). Largest possible is %lu "
+ "bytes.\n", len, PAGE_SIZE);
+ return -ENOMEM;
+ }
+ tfm = crypto_alloc_tfm("sha1", 0);
+ if (tfm == NULL) {
+ seclvl_printk(0, KERN_ERR,
+ "Failed to load transform for SHA1\n");
+ return -ENOSYS;
+ }
+ // Just get a new page; don't play around with page boundaries
+ // and scatterlists.
+ pgVirtAddr = (char *)__get_free_page(GFP_KERNEL);
+ sg[0].page = virt_to_page(pgVirtAddr);
+ sg[0].offset = 0;
+ sg[0].length = len;
+ strncpy(pgVirtAddr, plaintext, len);
+ crypto_digest_init(tfm);
+ crypto_digest_update(tfm, sg, 1);
+ crypto_digest_final(tfm, hash);
+ crypto_free_tfm(tfm);
+ free_page((unsigned long)pgVirtAddr);
+ return 0;
+}
+
+/**
+ * Called whenever the user writes to the sysfs passwd handle to this kernel
+ * object. It hashes the password and compares the hashed results.
+ */
+static ssize_t
+seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
+{
+ int i;
+ unsigned char tmp[SHA1_DIGEST_SIZE];
+ int rc;
+ int len;
+ if (!*passwd && !*sha1_passwd) {
+ seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the "
+ "seclvl module, but neither a plain text "
+ "password nor a SHA1 hashed password was "
+ "passed in as a module parameter! This is a "
+ "bug, since it should not be possible to be in "
+ "this part of the module; please tell a "
+ "maintainer about this event.\n");
+ return -EINVAL;
+ }
+ len = strlen(buff);
+ /* ``echo "secret" > seclvl/passwd'' includes a newline */
+ if (buff[len - 1] == '\n') {
+ len--;
+ }
+ /* Hash the password, then compare the hashed values */
+ if ((rc = plaintext_to_sha1(tmp, buff, len))) {
+ seclvl_printk(0, KERN_ERR, "Error hashing password: rc = "
+ "[%d]\n", rc);
+ return rc;
+ }
+ for (i = 0; i < SHA1_DIGEST_SIZE; i++) {
+ if (hashedPassword[i] != tmp[i]) {
+ return -EPERM;
+ }
+ }
+ seclvl_printk(0, KERN_INFO,
+ "Password accepted; seclvl reduced to 0.\n");
+ seclvl = 0;
+ return count;
+}
+
+/* Generate sysfs_attr_passwd */
+struct seclvl_attribute sysfs_attr_passwd =
+__ATTR(passwd, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_passwd,
+ seclvl_write_passwd);
+
+/**
+ * Explicitely disallow ptrace'ing the init process.
+ */
+static int seclvl_ptrace(struct task_struct *parent, struct task_struct *child)
+{
+ if (seclvl >= 0) {
+ if (child->pid == 1) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to ptrace "
+ "the init process dissallowed in "
+ "secure level %d\n", seclvl);
+ return -EPERM;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Capability checks for seclvl. The majority of the policy
+ * enforcement for seclvl takes place here.
+ */
+static int seclvl_capable(struct task_struct *tsk, int cap)
+{
+ /* init can do anything it wants */
+ if (tsk->pid == 1)
+ return 0;
+
+ switch (seclvl) {
+ case 2:
+ /* fall through */
+ case 1:
+ if (cap == CAP_LINUX_IMMUTABLE) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to modify "
+ "the IMMUTABLE and/or APPEND extended "
+ "attribute on a file with the IMMUTABLE "
+ "and/or APPEND extended attribute set "
+ "denied in seclvl [%d]\n", seclvl);
+ return -EPERM;
+ } else if (cap == CAP_SYS_RAWIO) { // Somewhat broad...
+ seclvl_printk(1, KERN_WARNING, "Attempt to perform "
+ "raw I/O while in secure level [%d] "
+ "denied\n", seclvl);
+ return -EPERM;
+ } else if (cap == CAP_NET_ADMIN) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to perform "
+ "network administrative task while "
+ "in secure level [%d] denied\n", seclvl);
+ return -EPERM;
+ } else if (cap == CAP_SETUID) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to setuid "
+ "while in secure level [%d] denied\n",
+ seclvl);
+ return -EPERM;
+ } else if (cap == CAP_SETGID) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to setgid "
+ "while in secure level [%d] denied\n",
+ seclvl);
+ } else if (cap == CAP_SYS_MODULE) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to perform "
+ "a module operation while in secure "
+ "level [%d] denied\n", seclvl);
+ return -EPERM;
+ }
+ break;
+ default:
+ break;
+ }
+ /* from dummy.c */
+ if (cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0)
+ return 0; /* capability granted */
+ seclvl_printk(1, KERN_WARNING, "Capability denied\n");
+ return -EPERM; /* capability denied */
+}
+
+/**
+ * Disallow reversing the clock in seclvl > 1
+ */
+static int seclvl_settime(struct timespec *tv, struct timezone *tz)
+{
+ struct timespec now;
+ if (seclvl > 1) {
+ now = current_kernel_time();
+ if (tv->tv_sec < now.tv_sec ||
+ (tv->tv_sec == now.tv_sec && tv->tv_nsec < now.tv_nsec)) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to decrement "
+ "time in secure level %d denied: "
+ "current->pid = [%d], "
+ "current->group_leader->pid = [%d]\n",
+ seclvl, current->pid,
+ current->group_leader->pid);
+ return -EPERM;
+ } /* if attempt to decrement time */
+ } /* if seclvl > 1 */
+ return 0;
+}
+
+/* claim the blockdev to exclude mounters, release on file close */
+static int seclvl_bd_claim(struct inode *inode)
+{
+ int holder;
+ struct block_device *bdev = NULL;
+ dev_t dev = inode->i_rdev;
+ bdev = open_by_devnum(dev, FMODE_WRITE);
+ if (bdev) {
+ if (bd_claim(bdev, &holder)) {
+ blkdev_put(bdev);
+ return -EPERM;
+ }
+ /* claimed, mark it to release on close */
+ inode->i_security = current;
+ }
+ return 0;
+}
+
+/* release the blockdev if you claimed it */
+static void seclvl_bd_release(struct inode *inode)
+{
+ if (inode && S_ISBLK(inode->i_mode) && inode->i_security == current) {
+ struct block_device *bdev = inode->i_bdev;
+ if (bdev) {
+ bd_release(bdev);
+ blkdev_put(bdev);
+ inode->i_security = NULL;
+ }
+ }
+}
+
+/**
+ * Security for writes to block devices is regulated by this seclvl
+ * function. Deny all writes to block devices in seclvl 2. In
+ * seclvl 1, we only deny writes to *mounted* block devices.
+ */
+static int
+seclvl_inode_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+ if (current->pid != 1 && S_ISBLK(inode->i_mode) && (mask & MAY_WRITE)) {
+ switch (seclvl) {
+ case 2:
+ seclvl_printk(1, KERN_WARNING, "Write to block device "
+ "denied in secure level [%d]\n", seclvl);
+ return -EPERM;
+ case 1:
+ if (seclvl_bd_claim(inode)) {
+ seclvl_printk(1, KERN_WARNING,
+ "Write to mounted block device "
+ "denied in secure level [%d]\n",
+ seclvl);
+ return -EPERM;
+ }
+ }
+ }
+ return 0;
+}
+
+/**
+ * The SUID and SGID bits cannot be set in seclvl >= 1
+ */
+static int seclvl_inode_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ if (seclvl > 0) {
+ if (iattr->ia_valid & ATTR_MODE)
+ if (iattr->ia_mode & S_ISUID ||
+ iattr->ia_mode & S_ISGID) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to "
+ "modify SUID or SGID bit "
+ "denied in seclvl [%d]\n",
+ seclvl);
+ return -EPERM;
+ }
+ }
+ return 0;
+}
+
+/* release busied block devices */
+static void seclvl_file_free_security(struct file *filp)
+{
+ struct dentry *dentry = filp->f_dentry;
+ struct inode *inode = NULL;
+
+ if (dentry) {
+ inode = dentry->d_inode;
+ seclvl_bd_release(inode);
+ }
+}
+
+/**
+ * Cannot unmount in secure level 2
+ */
+static int seclvl_umount(struct vfsmount *mnt, int flags)
+{
+ if (current->pid == 1) {
+ return 0;
+ }
+ if (seclvl == 2) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to unmount in secure "
+ "level %d\n", seclvl);
+ return -EPERM;
+ }
+ return 0;
+}
+
+static struct security_operations seclvl_ops = {
+ .ptrace = seclvl_ptrace,
+ .capable = seclvl_capable,
+ .inode_permission = seclvl_inode_permission,
+ .inode_setattr = seclvl_inode_setattr,
+ .file_free_security = seclvl_file_free_security,
+ .settime = seclvl_settime,
+ .sb_umount = seclvl_umount,
+};
+
+/**
+ * Process the password-related module parameters
+ */
+static int processPassword(void)
+{
+ int rc = 0;
+ hashedPassword[0] = '\0';
+ if (*passwd) {
+ if (*sha1_passwd) {
+ seclvl_printk(0, KERN_ERR, "Error: Both "
+ "passwd and sha1_passwd "
+ "were set, but they are mutually "
+ "exclusive.\n");
+ return -EINVAL;
+ }
+ if ((rc = plaintext_to_sha1(hashedPassword, passwd,
+ strlen(passwd)))) {
+ seclvl_printk(0, KERN_ERR, "Error: SHA1 support not "
+ "in kernel\n");
+ return rc;
+ }
+ /* All static data goes to the BSS, which zero's the
+ * plaintext password out for us. */
+ } else if (*sha1_passwd) { // Base 16
+ int i;
+ i = strlen(sha1_passwd);
+ if (i != (SHA1_DIGEST_SIZE * 2)) {
+ seclvl_printk(0, KERN_ERR, "Received [%d] bytes; "
+ "expected [%d] for the hexadecimal "
+ "representation of the SHA1 hash of "
+ "the password.\n",
+ i, (SHA1_DIGEST_SIZE * 2));
+ return -EINVAL;
+ }
+ while ((i -= 2) + 2) {
+ unsigned char tmp;
+ tmp = sha1_passwd[i + 2];
+ sha1_passwd[i + 2] = '\0';
+ hashedPassword[i / 2] = (unsigned char)
+ simple_strtol(&sha1_passwd[i], NULL, 16);
+ sha1_passwd[i + 2] = tmp;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Sysfs registrations
+ */
+static int doSysfsRegistrations(void)
+{
+ int rc = 0;
+ if ((rc = subsystem_register(&seclvl_subsys))) {
+ seclvl_printk(0, KERN_WARNING,
+ "Error [%d] registering seclvl subsystem\n", rc);
+ return rc;
+ }
+ sysfs_create_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+ if (*passwd || *sha1_passwd) {
+ sysfs_create_file(&seclvl_subsys.kset.kobj,
+ &sysfs_attr_passwd.attr);
+ }
+ return 0;
+}
+
+/**
+ * Initialize the seclvl module.
+ */
+static int __init seclvl_init(void)
+{
+ int rc = 0;
+ if (verbosity < 0 || verbosity > 1) {
+ printk(KERN_ERR "Error: bad verbosity [%d]; only 0 or 1 "
+ "are valid values\n", verbosity);
+ rc = -EINVAL;
+ goto exit;
+ }
+ sysfs_attr_seclvl.attr.owner = THIS_MODULE;
+ sysfs_attr_passwd.attr.owner = THIS_MODULE;
+ if (initlvl < -1 || initlvl > 2) {
+ seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel "
+ "[%d].\n", initlvl);
+ rc = -EINVAL;
+ goto exit;
+ }
+ seclvl = initlvl;
+ if ((rc = processPassword())) {
+ seclvl_printk(0, KERN_ERR, "Error processing the password "
+ "module parameter(s): rc = [%d]\n", rc);
+ goto exit;
+ }
+ /* register ourselves with the security framework */
+ if (register_security(&seclvl_ops)) {
+ seclvl_printk(0, KERN_ERR,
+ "seclvl: Failure registering with the "
+ "kernel.\n");
+ /* try registering with primary module */
+ rc = mod_reg_security(MY_NAME, &seclvl_ops);
+ if (rc) {
+ seclvl_printk(0, KERN_ERR, "seclvl: Failure "
+ "registering with primary security "
+ "module.\n");
+ goto exit;
+ } /* if primary module registered */
+ secondary = 1;
+ } /* if we registered ourselves with the security framework */
+ if ((rc = doSysfsRegistrations())) {
+ seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
+ goto exit;
+ }
+ seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n");
+ exit:
+ if (rc) {
+ printk(KERN_ERR "seclvl: Error during initialization: rc = "
+ "[%d]\n", rc);
+ }
+ return rc;
+}
+
+/**
+ * Remove the seclvl module.
+ */
+static void __exit seclvl_exit(void)
+{
+ sysfs_remove_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+ if (*passwd || *sha1_passwd) {
+ sysfs_remove_file(&seclvl_subsys.kset.kobj,
+ &sysfs_attr_passwd.attr);
+ }
+ subsystem_unregister(&seclvl_subsys);
+ if (secondary == 1) {
+ mod_unreg_security(MY_NAME, &seclvl_ops);
+ } else if (unregister_security(&seclvl_ops)) {
+ seclvl_printk(0, KERN_INFO,
+ "seclvl: Failure unregistering with the "
+ "kernel\n");
+ }
+}
+
+module_init(seclvl_init);
+module_exit(seclvl_exit);
+
+MODULE_AUTHOR("Michael A. Halcrow <mike@halcrow.us>");
+MODULE_DESCRIPTION("LSM implementation of the BSD Secure Levels");
+MODULE_LICENSE("GPL");
\
 
 \ /
  Last update: 2005-03-22 14:05    [W:0.220 / U:0.316 seconds]
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