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-rw-r--r--security/smack/smack_lsm.c2518
1 files changed, 2518 insertions, 0 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
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index 000000000000..1c11e4245859
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+++ b/security/smack/smack_lsm.c
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+/*
+ * Simplified MAC Kernel (smack) security module
+ *
+ * This file contains the smack hook function implementations.
+ *
+ * Author:
+ * Casey Schaufler <casey@schaufler-ca.com>
+ *
+ * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/xattr.h>
+#include <linux/pagemap.h>
+#include <linux/mount.h>
+#include <linux/stat.h>
+#include <linux/ext2_fs.h>
+#include <linux/kd.h>
+#include <asm/ioctls.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/mutex.h>
+#include <linux/pipe_fs_i.h>
+#include <net/netlabel.h>
+#include <net/cipso_ipv4.h>
+
+#include "smack.h"
+
+/*
+ * I hope these are the hokeyist lines of code in the module. Casey.
+ */
+#define DEVPTS_SUPER_MAGIC 0x1cd1
+#define SOCKFS_MAGIC 0x534F434B
+#define TMPFS_MAGIC 0x01021994
+
+/**
+ * smk_fetch - Fetch the smack label from a file.
+ * @ip: a pointer to the inode
+ * @dp: a pointer to the dentry
+ *
+ * Returns a pointer to the master list entry for the Smack label
+ * or NULL if there was no label to fetch.
+ */
+static char *smk_fetch(struct inode *ip, struct dentry *dp)
+{
+ int rc;
+ char in[SMK_LABELLEN];
+
+ if (ip->i_op->getxattr == NULL)
+ return NULL;
+
+ rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN);
+ if (rc < 0)
+ return NULL;
+
+ return smk_import(in, rc);
+}
+
+/**
+ * new_inode_smack - allocate an inode security blob
+ * @smack: a pointer to the Smack label to use in the blob
+ *
+ * Returns the new blob or NULL if there's no memory available
+ */
+struct inode_smack *new_inode_smack(char *smack)
+{
+ struct inode_smack *isp;
+
+ isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
+ if (isp == NULL)
+ return NULL;
+
+ isp->smk_inode = smack;
+ isp->smk_flags = 0;
+ mutex_init(&isp->smk_lock);
+
+ return isp;
+}
+
+/*
+ * LSM hooks.
+ * We he, that is fun!
+ */
+
+/**
+ * smack_ptrace - Smack approval on ptrace
+ * @ptp: parent task pointer
+ * @ctp: child task pointer
+ *
+ * Returns 0 if access is OK, an error code otherwise
+ *
+ * Do the capability checks, and require read and write.
+ */
+static int smack_ptrace(struct task_struct *ptp, struct task_struct *ctp)
+{
+ int rc;
+
+ rc = cap_ptrace(ptp, ctp);
+ if (rc != 0)
+ return rc;
+
+ rc = smk_access(ptp->security, ctp->security, MAY_READWRITE);
+ if (rc != 0 && __capable(ptp, CAP_MAC_OVERRIDE))
+ return 0;
+
+ return rc;
+}
+
+/**
+ * smack_syslog - Smack approval on syslog
+ * @type: message type
+ *
+ * Require that the task has the floor label
+ *
+ * Returns 0 on success, error code otherwise.
+ */
+static int smack_syslog(int type)
+{
+ int rc;
+ char *sp = current->security;
+
+ rc = cap_syslog(type);
+ if (rc != 0)
+ return rc;
+
+ if (capable(CAP_MAC_OVERRIDE))
+ return 0;
+
+ if (sp != smack_known_floor.smk_known)
+ rc = -EACCES;
+
+ return rc;
+}
+
+
+/*
+ * Superblock Hooks.
+ */
+
+/**
+ * smack_sb_alloc_security - allocate a superblock blob
+ * @sb: the superblock getting the blob
+ *
+ * Returns 0 on success or -ENOMEM on error.
+ */
+static int smack_sb_alloc_security(struct super_block *sb)
+{
+ struct superblock_smack *sbsp;
+
+ sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
+
+ if (sbsp == NULL)
+ return -ENOMEM;
+
+ sbsp->smk_root = smack_known_floor.smk_known;
+ sbsp->smk_default = smack_known_floor.smk_known;
+ sbsp->smk_floor = smack_known_floor.smk_known;
+ sbsp->smk_hat = smack_known_hat.smk_known;
+ sbsp->smk_initialized = 0;
+ spin_lock_init(&sbsp->smk_sblock);
+
+ sb->s_security = sbsp;
+
+ return 0;
+}
+
+/**
+ * smack_sb_free_security - free a superblock blob
+ * @sb: the superblock getting the blob
+ *
+ */
+static void smack_sb_free_security(struct super_block *sb)
+{
+ kfree(sb->s_security);
+ sb->s_security = NULL;
+}
+
+/**
+ * smack_sb_copy_data - copy mount options data for processing
+ * @type: file system type
+ * @orig: where to start
+ * @smackopts
+ *
+ * Returns 0 on success or -ENOMEM on error.
+ *
+ * Copy the Smack specific mount options out of the mount
+ * options list.
+ */
+static int smack_sb_copy_data(struct file_system_type *type, void *orig,
+ void *smackopts)
+{
+ char *cp, *commap, *otheropts, *dp;
+
+ /* Binary mount data: just copy */
+ if (type->fs_flags & FS_BINARY_MOUNTDATA) {
+ copy_page(smackopts, orig);
+ return 0;
+ }
+
+ otheropts = (char *)get_zeroed_page(GFP_KERNEL);
+ if (otheropts == NULL)
+ return -ENOMEM;
+
+ for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
+ if (strstr(cp, SMK_FSDEFAULT) == cp)
+ dp = smackopts;
+ else if (strstr(cp, SMK_FSFLOOR) == cp)
+ dp = smackopts;
+ else if (strstr(cp, SMK_FSHAT) == cp)
+ dp = smackopts;
+ else if (strstr(cp, SMK_FSROOT) == cp)
+ dp = smackopts;
+ else
+ dp = otheropts;
+
+ commap = strchr(cp, ',');
+ if (commap != NULL)
+ *commap = '\0';
+
+ if (*dp != '\0')
+ strcat(dp, ",");
+ strcat(dp, cp);
+ }
+
+ strcpy(orig, otheropts);
+ free_page((unsigned long)otheropts);
+
+ return 0;
+}
+
+/**
+ * smack_sb_kern_mount - Smack specific mount processing
+ * @sb: the file system superblock
+ * @data: the smack mount options
+ *
+ * Returns 0 on success, an error code on failure
+ */
+static int smack_sb_kern_mount(struct super_block *sb, void *data)
+{
+ struct dentry *root = sb->s_root;
+ struct inode *inode = root->d_inode;
+ struct superblock_smack *sp = sb->s_security;
+ struct inode_smack *isp;
+ char *op;
+ char *commap;
+ char *nsp;
+
+ spin_lock(&sp->smk_sblock);
+ if (sp->smk_initialized != 0) {
+ spin_unlock(&sp->smk_sblock);
+ return 0;
+ }
+ sp->smk_initialized = 1;
+ spin_unlock(&sp->smk_sblock);
+
+ for (op = data; op != NULL; op = commap) {
+ commap = strchr(op, ',');
+ if (commap != NULL)
+ *commap++ = '\0';
+
+ if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
+ op += strlen(SMK_FSHAT);
+ nsp = smk_import(op, 0);
+ if (nsp != NULL)
+ sp->smk_hat = nsp;
+ } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
+ op += strlen(SMK_FSFLOOR);
+ nsp = smk_import(op, 0);
+ if (nsp != NULL)
+ sp->smk_floor = nsp;
+ } else if (strncmp(op, SMK_FSDEFAULT,
+ strlen(SMK_FSDEFAULT)) == 0) {
+ op += strlen(SMK_FSDEFAULT);
+ nsp = smk_import(op, 0);
+ if (nsp != NULL)
+ sp->smk_default = nsp;
+ } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
+ op += strlen(SMK_FSROOT);
+ nsp = smk_import(op, 0);
+ if (nsp != NULL)
+ sp->smk_root = nsp;
+ }
+ }
+
+ /*
+ * Initialize the root inode.
+ */
+ isp = inode->i_security;
+ if (isp == NULL)
+ inode->i_security = new_inode_smack(sp->smk_root);
+ else
+ isp->smk_inode = sp->smk_root;
+
+ return 0;
+}
+
+/**
+ * smack_sb_statfs - Smack check on statfs
+ * @dentry: identifies the file system in question
+ *
+ * Returns 0 if current can read the floor of the filesystem,
+ * and error code otherwise
+ */
+static int smack_sb_statfs(struct dentry *dentry)
+{
+ struct superblock_smack *sbp = dentry->d_sb->s_security;
+
+ return smk_curacc(sbp->smk_floor, MAY_READ);
+}
+
+/**
+ * smack_sb_mount - Smack check for mounting
+ * @dev_name: unused
+ * @nd: mount point
+ * @type: unused
+ * @flags: unused
+ * @data: unused
+ *
+ * Returns 0 if current can write the floor of the filesystem
+ * being mounted on, an error code otherwise.
+ */
+static int smack_sb_mount(char *dev_name, struct nameidata *nd,
+ char *type, unsigned long flags, void *data)
+{
+ struct superblock_smack *sbp = nd->mnt->mnt_sb->s_security;
+
+ return smk_curacc(sbp->smk_floor, MAY_WRITE);
+}
+
+/**
+ * smack_sb_umount - Smack check for unmounting
+ * @mnt: file system to unmount
+ * @flags: unused
+ *
+ * Returns 0 if current can write the floor of the filesystem
+ * being unmounted, an error code otherwise.
+ */
+static int smack_sb_umount(struct vfsmount *mnt, int flags)
+{
+ struct superblock_smack *sbp;
+
+ sbp = mnt->mnt_sb->s_security;
+
+ return smk_curacc(sbp->smk_floor, MAY_WRITE);
+}
+
+/*
+ * Inode hooks
+ */
+
+/**
+ * smack_inode_alloc_security - allocate an inode blob
+ * @inode - the inode in need of a blob
+ *
+ * Returns 0 if it gets a blob, -ENOMEM otherwise
+ */
+static int smack_inode_alloc_security(struct inode *inode)
+{
+ inode->i_security = new_inode_smack(current->security);
+ if (inode->i_security == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+/**
+ * smack_inode_free_security - free an inode blob
+ * @inode - the inode with a blob
+ *
+ * Clears the blob pointer in inode
+ */
+static void smack_inode_free_security(struct inode *inode)
+{
+ kfree(inode->i_security);
+ inode->i_security = NULL;
+}
+
+/**
+ * smack_inode_init_security - copy out the smack from an inode
+ * @inode: the inode
+ * @dir: unused
+ * @name: where to put the attribute name
+ * @value: where to put the attribute value
+ * @len: where to put the length of the attribute
+ *
+ * Returns 0 if it all works out, -ENOMEM if there's no memory
+ */
+static int smack_inode_init_security(struct inode *inode, struct inode *dir,
+ char **name, void **value, size_t *len)
+{
+ char *isp = smk_of_inode(inode);
+
+ if (name) {
+ *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
+ if (*name == NULL)
+ return -ENOMEM;
+ }
+
+ if (value) {
+ *value = kstrdup(isp, GFP_KERNEL);
+ if (*value == NULL)
+ return -ENOMEM;
+ }
+
+ if (len)
+ *len = strlen(isp) + 1;
+
+ return 0;
+}
+
+/**
+ * smack_inode_link - Smack check on link
+ * @old_dentry: the existing object
+ * @dir: unused
+ * @new_dentry: the new object
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *new_dentry)
+{
+ int rc;
+ char *isp;
+
+ isp = smk_of_inode(old_dentry->d_inode);
+ rc = smk_curacc(isp, MAY_WRITE);
+
+ if (rc == 0 && new_dentry->d_inode != NULL) {
+ isp = smk_of_inode(new_dentry->d_inode);
+ rc = smk_curacc(isp, MAY_WRITE);
+ }
+
+ return rc;
+}
+
+/**
+ * smack_inode_unlink - Smack check on inode deletion
+ * @dir: containing directory object
+ * @dentry: file to unlink
+ *
+ * Returns 0 if current can write the containing directory
+ * and the object, error code otherwise
+ */
+static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *ip = dentry->d_inode;
+ int rc;
+
+ /*
+ * You need write access to the thing you're unlinking
+ */
+ rc = smk_curacc(smk_of_inode(ip), MAY_WRITE);
+ if (rc == 0)
+ /*
+ * You also need write access to the containing directory
+ */
+ rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
+
+ return rc;
+}
+
+/**
+ * smack_inode_rmdir - Smack check on directory deletion
+ * @dir: containing directory object
+ * @dentry: directory to unlink
+ *
+ * Returns 0 if current can write the containing directory
+ * and the directory, error code otherwise
+ */
+static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ int rc;
+
+ /*
+ * You need write access to the thing you're removing
+ */
+ rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+ if (rc == 0)
+ /*
+ * You also need write access to the containing directory
+ */
+ rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
+
+ return rc;
+}
+
+/**
+ * smack_inode_rename - Smack check on rename
+ * @old_inode: the old directory
+ * @old_dentry: unused
+ * @new_inode: the new directory
+ * @new_dentry: unused
+ *
+ * Read and write access is required on both the old and
+ * new directories.
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_rename(struct inode *old_inode,
+ struct dentry *old_dentry,
+ struct inode *new_inode,
+ struct dentry *new_dentry)
+{
+ int rc;
+ char *isp;
+
+ isp = smk_of_inode(old_dentry->d_inode);
+ rc = smk_curacc(isp, MAY_READWRITE);
+
+ if (rc == 0 && new_dentry->d_inode != NULL) {
+ isp = smk_of_inode(new_dentry->d_inode);
+ rc = smk_curacc(isp, MAY_READWRITE);
+ }
+
+ return rc;
+}
+
+/**
+ * smack_inode_permission - Smack version of permission()
+ * @inode: the inode in question
+ * @mask: the access requested
+ * @nd: unused
+ *
+ * This is the important Smack hook.
+ *
+ * Returns 0 if access is permitted, -EACCES otherwise
+ */
+static int smack_inode_permission(struct inode *inode, int mask,
+ struct nameidata *nd)
+{
+ /*
+ * No permission to check. Existence test. Yup, it's there.
+ */
+ if (mask == 0)
+ return 0;
+
+ return smk_curacc(smk_of_inode(inode), mask);
+}
+
+/**
+ * smack_inode_setattr - Smack check for setting attributes
+ * @dentry: the object
+ * @iattr: for the force flag
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ /*
+ * Need to allow for clearing the setuid bit.
+ */
+ if (iattr->ia_valid & ATTR_FORCE)
+ return 0;
+
+ return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+}
+
+/**
+ * smack_inode_getattr - Smack check for getting attributes
+ * @mnt: unused
+ * @dentry: the object
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
+{
+ return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
+}
+
+/**
+ * smack_inode_setxattr - Smack check for setting xattrs
+ * @dentry: the object
+ * @name: name of the attribute
+ * @value: unused
+ * @size: unused
+ * @flags: unused
+ *
+ * This protects the Smack attribute explicitly.
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_setxattr(struct dentry *dentry, char *name,
+ void *value, size_t size, int flags)
+{
+ if (!capable(CAP_MAC_ADMIN)) {
+ if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKIPOUT) == 0)
+ return -EPERM;
+ }
+
+ return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+}
+
+/**
+ * smack_inode_post_setxattr - Apply the Smack update approved above
+ * @dentry: object
+ * @name: attribute name
+ * @value: attribute value
+ * @size: attribute size
+ * @flags: unused
+ *
+ * Set the pointer in the inode blob to the entry found
+ * in the master label list.
+ */
+static void smack_inode_post_setxattr(struct dentry *dentry, char *name,
+ void *value, size_t size, int flags)
+{
+ struct inode_smack *isp;
+ char *nsp;
+
+ /*
+ * Not SMACK
+ */
+ if (strcmp(name, XATTR_NAME_SMACK))
+ return;
+
+ if (size >= SMK_LABELLEN)
+ return;
+
+ isp = dentry->d_inode->i_security;
+
+ /*
+ * No locking is done here. This is a pointer
+ * assignment.
+ */
+ nsp = smk_import(value, size);
+ if (nsp != NULL)
+ isp->smk_inode = nsp;
+ else
+ isp->smk_inode = smack_known_invalid.smk_known;
+
+ return;
+}
+
+/*
+ * smack_inode_getxattr - Smack check on getxattr
+ * @dentry: the object
+ * @name: unused
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_getxattr(struct dentry *dentry, char *name)
+{
+ return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
+}
+
+/*
+ * smack_inode_removexattr - Smack check on removexattr
+ * @dentry: the object
+ * @name: name of the attribute
+ *
+ * Removing the Smack attribute requires CAP_MAC_ADMIN
+ *
+ * Returns 0 if access is permitted, an error code otherwise
+ */
+static int smack_inode_removexattr(struct dentry *dentry, char *name)
+{
+ if (strcmp(name, XATTR_NAME_SMACK) == 0 && !capable(CAP_MAC_ADMIN))
+ return -EPERM;
+
+ return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+}
+
+/**
+ * smack_inode_getsecurity - get smack xattrs
+ * @inode: the object
+ * @name: attribute name
+ * @buffer: where to put the result
+ * @size: size of the buffer
+ * @err: unused
+ *
+ * Returns the size of the attribute or an error code
+ */
+static int smack_inode_getsecurity(const struct inode *inode,
+ const char *name, void **buffer,
+ bool alloc)
+{
+ struct socket_smack *ssp;
+ struct socket *sock;
+ struct super_block *sbp;
+ struct inode *ip = (struct inode *)inode;
+ char *isp;
+ int ilen;
+ int rc = 0;
+
+ if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
+ isp = smk_of_inode(inode);
+ ilen = strlen(isp) + 1;
+ *buffer = isp;
+ return ilen;
+ }
+
+ /*
+ * The rest of the Smack xattrs are only on sockets.
+ */
+ sbp = ip->i_sb;
+ if (sbp->s_magic != SOCKFS_MAGIC)
+ return -EOPNOTSUPP;
+
+ sock = SOCKET_I(ip);
+ if (sock == NULL)
+ return -EOPNOTSUPP;
+
+ ssp = sock->sk->sk_security;
+
+ if (strcmp(name, XATTR_SMACK_IPIN) == 0)
+ isp = ssp->smk_in;
+ else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
+ isp = ssp->smk_out;
+ else
+ return -EOPNOTSUPP;
+
+ ilen = strlen(isp) + 1;
+ if (rc == 0) {
+ *buffer = isp;
+ rc = ilen;
+ }
+
+ return rc;
+}
+
+
+/**
+ * smack_inode_listsecurity - list the Smack attributes
+ * @inode: the object
+ * @buffer: where they go
+ * @buffer_size: size of buffer
+ *
+ * Returns 0 on success, -EINVAL otherwise
+ */
+static int smack_inode_listsecurity(struct inode *inode, char *buffer,
+ size_t buffer_size)
+{
+ int len = strlen(XATTR_NAME_SMACK);
+
+ if (buffer != NULL && len <= buffer_size) {
+ memcpy(buffer, XATTR_NAME_SMACK, len);
+ return len;
+ }
+ return -EINVAL;
+}
+
+/*
+ * File Hooks
+ */
+
+/**
+ * smack_file_permission - Smack check on file operations
+ * @file: unused
+ * @mask: unused
+ *
+ * Returns 0
+ *
+ * Should access checks be done on each read or write?
+ * UNICOS and SELinux say yes.
+ * Trusted Solaris, Trusted Irix, and just about everyone else says no.
+ *
+ * I'll say no for now. Smack does not do the frequent
+ * label changing that SELinux does.
+ */
+static int smack_file_permission(struct file *file, int mask)
+{
+ return 0;
+}
+
+/**
+ * smack_file_alloc_security - assign a file security blob
+ * @file: the object
+ *
+ * The security blob for a file is a pointer to the master
+ * label list, so no allocation is done.
+ *
+ * Returns 0
+ */
+static int smack_file_alloc_security(struct file *file)
+{
+ file->f_security = current->security;
+ return 0;
+}
+
+/**
+ * smack_file_free_security - clear a file security blob
+ * @file: the object
+ *
+ * The security blob for a file is a pointer to the master
+ * label list, so no memory is freed.
+ */
+static void smack_file_free_security(struct file *file)
+{
+ file->f_security = NULL;
+}
+
+/**
+ * smack_file_ioctl - Smack check on ioctls
+ * @file: the object
+ * @cmd: what to do
+ * @arg: unused
+ *
+ * Relies heavily on the correct use of the ioctl command conventions.
+ *
+ * Returns 0 if allowed, error code otherwise
+ */
+static int smack_file_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int rc = 0;
+
+ if (_IOC_DIR(cmd) & _IOC_WRITE)
+ rc = smk_curacc(file->f_security, MAY_WRITE);
+
+ if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
+ rc = smk_curacc(file->f_security, MAY_READ);
+
+ return rc;
+}
+
+/**
+ * smack_file_lock - Smack check on file locking
+ * @file: the object
+ * @cmd unused
+ *
+ * Returns 0 if current has write access, error code otherwise
+ */
+static int smack_file_lock(struct file *file, unsigned int cmd)
+{
+ return smk_curacc(file->f_security, MAY_WRITE);
+}
+
+/**
+ * smack_file_fcntl - Smack check on fcntl
+ * @file: the object
+ * @cmd: what action to check
+ * @arg: unused
+ *
+ * Returns 0 if current has access, error code otherwise
+ */
+static int smack_file_fcntl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int rc;
+
+ switch (cmd) {
+ case F_DUPFD:
+ case F_GETFD:
+ case F_GETFL:
+ case F_GETLK:
+ case F_GETOWN:
+ case F_GETSIG:
+ rc = smk_curacc(file->f_security, MAY_READ);
+ break;
+ case F_SETFD:
+ case F_SETFL:
+ case F_SETLK:
+ case F_SETLKW:
+ case F_SETOWN:
+ case F_SETSIG:
+ rc = smk_curacc(file->f_security, MAY_WRITE);
+ break;
+ default:
+ rc = smk_curacc(file->f_security, MAY_READWRITE);
+ }
+
+ return rc;
+}
+
+/**
+ * smack_file_set_fowner - set the file security blob value
+ * @file: object in question
+ *
+ * Returns 0
+ * Further research may be required on this one.
+ */
+static int smack_file_set_fowner(struct file *file)
+{
+ file->f_security = current->security;
+ return 0;
+}
+
+/**
+ * smack_file_send_sigiotask - Smack on sigio
+ * @tsk: The target task
+ * @fown: the object the signal come from
+ * @signum: unused
+ *
+ * Allow a privileged task to get signals even if it shouldn't
+ *
+ * Returns 0 if a subject with the object's smack could
+ * write to the task, an error code otherwise.
+ */
+static int smack_file_send_sigiotask(struct task_struct *tsk,
+ struct fown_struct *fown, int signum)
+{
+ struct file *file;
+ int rc;
+
+ /*
+ * struct fown_struct is never outside the context of a struct file
+ */
+ file = container_of(fown, struct file, f_owner);
+ rc = smk_access(file->f_security, tsk->security, MAY_WRITE);
+ if (rc != 0 && __capable(tsk, CAP_MAC_OVERRIDE))
+ return 0;
+ return rc;
+}
+
+/**
+ * smack_file_receive - Smack file receive check
+ * @file: the object
+ *
+ * Returns 0 if current has access, error code otherwise
+ */
+static int smack_file_receive(struct file *file)
+{
+ int may = 0;
+
+ /*
+ * This code relies on bitmasks.
+ */
+ if (file->f_mode & FMODE_READ)
+ may = MAY_READ;
+ if (file->f_mode & FMODE_WRITE)
+ may |= MAY_WRITE;
+
+ return smk_curacc(file->f_security, may);
+}
+
+/*
+ * Task hooks
+ */
+
+/**
+ * smack_task_alloc_security - "allocate" a task blob
+ * @tsk: the task in need of a blob
+ *
+ * Smack isn't using copies of blobs. Everyone
+ * points to an immutable list. No alloc required.
+ * No data copy required.
+ *
+ * Always returns 0
+ */
+static int smack_task_alloc_security(struct task_struct *tsk)
+{
+ tsk->security = current->security;
+
+ return 0;
+}
+
+/**
+ * smack_task_free_security - "free" a task blob
+ * @task: the task with the blob
+ *
+ * Smack isn't using copies of blobs. Everyone
+ * points to an immutable list. The blobs never go away.
+ * There is no leak here.
+ */
+static void smack_task_free_security(struct task_struct *task)
+{
+ task->security = NULL;
+}
+
+/**
+ * smack_task_setpgid - Smack check on setting pgid
+ * @p: the task object
+ * @pgid: unused
+ *
+ * Return 0 if write access is permitted
+ */
+static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
+{
+ return smk_curacc(p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_getpgid - Smack access check for getpgid
+ * @p: the object task
+ *
+ * Returns 0 if current can read the object task, error code otherwise
+ */
+static int smack_task_getpgid(struct task_struct *p)
+{
+ return smk_curacc(p->security, MAY_READ);
+}
+
+/**
+ * smack_task_getsid - Smack access check for getsid
+ * @p: the object task
+ *
+ * Returns 0 if current can read the object task, error code otherwise
+ */
+static int smack_task_getsid(struct task_struct *p)
+{
+ return smk_curacc(p->security, MAY_READ);
+}
+
+/**
+ * smack_task_getsecid - get the secid of the task
+ * @p: the object task
+ * @secid: where to put the result
+ *
+ * Sets the secid to contain a u32 version of the smack label.
+ */
+static void smack_task_getsecid(struct task_struct *p, u32 *secid)
+{
+ *secid = smack_to_secid(p->security);
+}
+
+/**
+ * smack_task_setnice - Smack check on setting nice
+ * @p: the task object
+ * @nice: unused
+ *
+ * Return 0 if write access is permitted
+ */
+static int smack_task_setnice(struct task_struct *p, int nice)
+{
+ return smk_curacc(p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_setioprio - Smack check on setting ioprio
+ * @p: the task object
+ * @ioprio: unused
+ *
+ * Return 0 if write access is permitted
+ */
+static int smack_task_setioprio(struct task_struct *p, int ioprio)
+{
+ return smk_curacc(p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_getioprio - Smack check on reading ioprio
+ * @p: the task object
+ *
+ * Return 0 if read access is permitted
+ */
+static int smack_task_getioprio(struct task_struct *p)
+{
+ return smk_curacc(p->security, MAY_READ);
+}
+
+/**
+ * smack_task_setscheduler - Smack check on setting scheduler
+ * @p: the task object
+ * @policy: unused
+ * @lp: unused
+ *
+ * Return 0 if read access is permitted
+ */
+static int smack_task_setscheduler(struct task_struct *p, int policy,
+ struct sched_param *lp)
+{
+ return smk_curacc(p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_getscheduler - Smack check on reading scheduler
+ * @p: the task object
+ *
+ * Return 0 if read access is permitted
+ */
+static int smack_task_getscheduler(struct task_struct *p)
+{
+ return smk_curacc(p->security, MAY_READ);
+}
+
+/**
+ * smack_task_movememory - Smack check on moving memory
+ * @p: the task object
+ *
+ * Return 0 if write access is permitted
+ */
+static int smack_task_movememory(struct task_struct *p)
+{
+ return smk_curacc(p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_kill - Smack check on signal delivery
+ * @p: the task object
+ * @info: unused
+ * @sig: unused
+ * @secid: identifies the smack to use in lieu of current's
+ *
+ * Return 0 if write access is permitted
+ *
+ * The secid behavior is an artifact of an SELinux hack
+ * in the USB code. Someday it may go away.
+ */
+static int smack_task_kill(struct task_struct *p, struct siginfo *info,
+ int sig, u32 secid)
+{
+ /*
+ * Special cases where signals really ought to go through
+ * in spite of policy. Stephen Smalley suggests it may
+ * make sense to change the caller so that it doesn't
+ * bother with the LSM hook in these cases.
+ */
+ if (info != SEND_SIG_NOINFO &&
+ (is_si_special(info) || SI_FROMKERNEL(info)))
+ return 0;
+ /*
+ * Sending a signal requires that the sender
+ * can write the receiver.
+ */
+ if (secid == 0)
+ return smk_curacc(p->security, MAY_WRITE);
+ /*
+ * If the secid isn't 0 we're dealing with some USB IO
+ * specific behavior. This is not clean. For one thing
+ * we can't take privilege into account.
+ */
+ return smk_access(smack_from_secid(secid), p->security, MAY_WRITE);
+}
+
+/**
+ * smack_task_wait - Smack access check for waiting
+ * @p: task to wait for
+ *
+ * Returns 0 if current can wait for p, error code otherwise
+ */
+static int smack_task_wait(struct task_struct *p)
+{
+ int rc;
+
+ rc = smk_access(current->security, p->security, MAY_WRITE);
+ if (rc == 0)
+ return 0;
+
+ /*
+ * Allow the operation to succeed if either task
+ * has privilege to perform operations that might
+ * account for the smack labels having gotten to
+ * be different in the first place.
+ *
+ * This breaks the strict subjet/object access
+ * control ideal, taking the object's privilege
+ * state into account in the decision as well as
+ * the smack value.
+ */
+ if (capable(CAP_MAC_OVERRIDE) || __capable(p, CAP_MAC_OVERRIDE))
+ return 0;
+
+ return rc;
+}
+
+/**
+ * smack_task_to_inode - copy task smack into the inode blob
+ * @p: task to copy from
+ * inode: inode to copy to
+ *
+ * Sets the smack pointer in the inode security blob
+ */
+static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
+{
+ struct inode_smack *isp = inode->i_security;
+ isp->smk_inode = p->security;
+}
+
+/*
+ * Socket hooks.
+ */
+
+/**
+ * smack_sk_alloc_security - Allocate a socket blob
+ * @sk: the socket
+ * @family: unused
+ * @priority: memory allocation priority
+ *
+ * Assign Smack pointers to current
+ *
+ * Returns 0 on success, -ENOMEM is there's no memory
+ */
+static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
+{
+ char *csp = current->security;
+ struct socket_smack *ssp;
+
+ ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
+ if (ssp == NULL)
+ return -ENOMEM;
+
+ ssp->smk_in = csp;
+ ssp->smk_out = csp;
+ ssp->smk_packet[0] = '\0';
+
+ sk->sk_security = ssp;
+
+ return 0;
+}
+
+/**
+ * smack_sk_free_security - Free a socket blob
+ * @sk: the socket
+ *
+ * Clears the blob pointer
+ */
+static void smack_sk_free_security(struct sock *sk)
+{
+ kfree(sk->sk_security);
+}
+
+/**
+ * smack_set_catset - convert a capset to netlabel mls categories
+ * @catset: the Smack categories
+ * @sap: where to put the netlabel categories
+ *
+ * Allocates and fills attr.mls.cat
+ */
+static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
+{
+ unsigned char *cp;
+ unsigned char m;
+ int cat;
+ int rc;
+ int byte;
+
+ if (catset == 0)
+ return;
+
+ sap->flags |= NETLBL_SECATTR_MLS_CAT;
+ sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
+ sap->attr.mls.cat->startbit = 0;
+
+ for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
+ for (m = 0x80; m != 0; m >>= 1, cat++) {
+ if ((m & *cp) == 0)
+ continue;
+ rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
+ cat, GFP_ATOMIC);
+ }
+}
+
+/**
+ * smack_to_secattr - fill a secattr from a smack value
+ * @smack: the smack value
+ * @nlsp: where the result goes
+ *
+ * Casey says that CIPSO is good enough for now.
+ * It can be used to effect.
+ * It can also be abused to effect when necessary.
+ * Appologies to the TSIG group in general and GW in particular.
+ */
+static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
+{
+ struct smack_cipso cipso;
+ int rc;
+
+ switch (smack_net_nltype) {
+ case NETLBL_NLTYPE_CIPSOV4:
+ nlsp->domain = NULL;
+ nlsp->flags = NETLBL_SECATTR_DOMAIN;
+ nlsp->flags |= NETLBL_SECATTR_MLS_LVL;
+
+ rc = smack_to_cipso(smack, &cipso);
+ if (rc == 0) {
+ nlsp->attr.mls.lvl = cipso.smk_level;
+ smack_set_catset(cipso.smk_catset, nlsp);
+ } else {
+ nlsp->attr.mls.lvl = smack_cipso_direct;
+ smack_set_catset(smack, nlsp);
+ }
+ break;
+ default:
+ break;
+ }
+}
+
+/**
+ * smack_netlabel - Set the secattr on a socket
+ * @sk: the socket
+ *
+ * Convert the outbound smack value (smk_out) to a
+ * secattr and attach it to the socket.
+ *
+ * Returns 0 on success or an error code
+ */
+static int smack_netlabel(struct sock *sk)
+{
+ struct socket_smack *ssp = sk->sk_security;
+ struct netlbl_lsm_secattr secattr;
+ int rc = 0;
+
+ netlbl_secattr_init(&secattr);
+ smack_to_secattr(ssp->smk_out, &secattr);
+ if (secattr.flags != NETLBL_SECATTR_NONE)
+ rc = netlbl_sock_setattr(sk, &secattr);
+
+ netlbl_secattr_destroy(&secattr);
+ return rc;
+}
+
+/**
+ * smack_inode_setsecurity - set smack xattrs
+ * @inode: the object
+ * @name: attribute name
+ * @value: attribute value
+ * @size: size of the attribute
+ * @flags: unused
+ *
+ * Sets the named attribute in the appropriate blob
+ *
+ * Returns 0 on success, or an error code
+ */
+static int smack_inode_setsecurity(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ char *sp;
+ struct inode_smack *nsp = inode->i_security;
+ struct socket_smack *ssp;
+ struct socket *sock;
+
+ if (value == NULL || size > SMK_LABELLEN)
+ return -EACCES;
+
+ sp = smk_import(value, size);
+ if (sp == NULL)
+ return -EINVAL;
+
+ if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
+ nsp->smk_inode = sp;
+ return 0;
+ }
+ /*
+ * The rest of the Smack xattrs are only on sockets.
+ */
+ if (inode->i_sb->s_magic != SOCKFS_MAGIC)
+ return -EOPNOTSUPP;
+
+ sock = SOCKET_I(inode);
+ if (sock == NULL)
+ return -EOPNOTSUPP;
+
+ ssp = sock->sk->sk_security;
+
+ if (strcmp(name, XATTR_SMACK_IPIN) == 0)
+ ssp->smk_in = sp;
+ else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
+ ssp->smk_out = sp;
+ return smack_netlabel(sock->sk);
+ } else
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+/**
+ * smack_socket_post_create - finish socket setup
+ * @sock: the socket
+ * @family: protocol family
+ * @type: unused
+ * @protocol: unused
+ * @kern: unused
+ *
+ * Sets the netlabel information on the socket
+ *
+ * Returns 0 on success, and error code otherwise
+ */
+static int smack_socket_post_create(struct socket *sock, int family,
+ int type, int protocol, int kern)
+{
+ if (family != PF_INET)
+ return 0;
+ /*
+ * Set the outbound netlbl.
+ */
+ return smack_netlabel(sock->sk);
+}
+
+/**
+ * smack_flags_to_may - convert S_ to MAY_ values
+ * @flags: the S_ value
+ *
+ * Returns the equivalent MAY_ value
+ */
+static int smack_flags_to_may(int flags)
+{
+ int may = 0;
+
+ if (flags & S_IRUGO)
+ may |= MAY_READ;
+ if (flags & S_IWUGO)
+ may |= MAY_WRITE;
+ if (flags & S_IXUGO)
+ may |= MAY_EXEC;
+
+ return may;
+}
+
+/**
+ * smack_msg_msg_alloc_security - Set the security blob for msg_msg
+ * @msg: the object
+ *
+ * Returns 0
+ */
+static int smack_msg_msg_alloc_security(struct msg_msg *msg)
+{
+ msg->security = current->security;
+ return 0;
+}
+
+/**
+ * smack_msg_msg_free_security - Clear the security blob for msg_msg
+ * @msg: the object
+ *
+ * Clears the blob pointer
+ */
+static void smack_msg_msg_free_security(struct msg_msg *msg)
+{
+ msg->security = NULL;
+}
+
+/**
+ * smack_of_shm - the smack pointer for the shm
+ * @shp: the object
+ *
+ * Returns a pointer to the smack value
+ */
+static char *smack_of_shm(struct shmid_kernel *shp)
+{
+ return (char *)shp->shm_perm.security;
+}
+
+/**
+ * smack_shm_alloc_security - Set the security blob for shm
+ * @shp: the object
+ *
+ * Returns 0
+ */
+static int smack_shm_alloc_security(struct shmid_kernel *shp)
+{
+ struct kern_ipc_perm *isp = &shp->shm_perm;
+
+ isp->security = current->security;
+ return 0;
+}
+
+/**
+ * smack_shm_free_security - Clear the security blob for shm
+ * @shp: the object
+ *
+ * Clears the blob pointer
+ */
+static void smack_shm_free_security(struct shmid_kernel *shp)
+{
+ struct kern_ipc_perm *isp = &shp->shm_perm;
+
+ isp->security = NULL;
+}
+
+/**
+ * smack_shm_associate - Smack access check for shm
+ * @shp: the object
+ * @shmflg: access requested
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
+{
+ char *ssp = smack_of_shm(shp);
+ int may;
+
+ may = smack_flags_to_may(shmflg);
+ return smk_curacc(ssp, may);
+}
+
+/**
+ * smack_shm_shmctl - Smack access check for shm
+ * @shp: the object
+ * @cmd: what it wants to do
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
+{
+ char *ssp = smack_of_shm(shp);
+ int may;
+
+ switch (cmd) {
+ case IPC_STAT:
+ case SHM_STAT:
+ may = MAY_READ;
+ break;
+ case IPC_SET:
+ case SHM_LOCK:
+ case SHM_UNLOCK:
+ case IPC_RMID:
+ may = MAY_READWRITE;
+ break;
+ case IPC_INFO:
+ case SHM_INFO:
+ /*
+ * System level information.
+ */
+ return 0;
+ default:
+ return -EINVAL;
+ }
+
+ return smk_curacc(ssp, may);
+}
+
+/**
+ * smack_shm_shmat - Smack access for shmat
+ * @shp: the object
+ * @shmaddr: unused
+ * @shmflg: access requested
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
+ int shmflg)
+{
+ char *ssp = smack_of_shm(shp);
+ int may;
+
+ may = smack_flags_to_may(shmflg);
+ return smk_curacc(ssp, may);
+}
+
+/**
+ * smack_of_sem - the smack pointer for the sem
+ * @sma: the object
+ *
+ * Returns a pointer to the smack value
+ */
+static char *smack_of_sem(struct sem_array *sma)
+{
+ return (char *)sma->sem_perm.security;
+}
+
+/**
+ * smack_sem_alloc_security - Set the security blob for sem
+ * @sma: the object
+ *
+ * Returns 0
+ */
+static int smack_sem_alloc_security(struct sem_array *sma)
+{
+ struct kern_ipc_perm *isp = &sma->sem_perm;
+
+ isp->security = current->security;
+ return 0;
+}
+
+/**
+ * smack_sem_free_security - Clear the security blob for sem
+ * @sma: the object
+ *
+ * Clears the blob pointer
+ */
+static void smack_sem_free_security(struct sem_array *sma)
+{
+ struct kern_ipc_perm *isp = &sma->sem_perm;
+
+ isp->security = NULL;
+}
+
+/**
+ * smack_sem_associate - Smack access check for sem
+ * @sma: the object
+ * @semflg: access requested
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_sem_associate(struct sem_array *sma, int semflg)
+{
+ char *ssp = smack_of_sem(sma);
+ int may;
+
+ may = smack_flags_to_may(semflg);
+ return smk_curacc(ssp, may);
+}
+
+/**
+ * smack_sem_shmctl - Smack access check for sem
+ * @sma: the object
+ * @cmd: what it wants to do
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_sem_semctl(struct sem_array *sma, int cmd)
+{
+ char *ssp = smack_of_sem(sma);
+ int may;
+
+ switch (cmd) {
+ case GETPID:
+ case GETNCNT:
+ case GETZCNT:
+ case GETVAL:
+ case GETALL:
+ case IPC_STAT:
+ case SEM_STAT:
+ may = MAY_READ;
+ break;
+ case SETVAL:
+ case SETALL:
+ case IPC_RMID:
+ case IPC_SET:
+ may = MAY_READWRITE;
+ break;
+ case IPC_INFO:
+ case SEM_INFO:
+ /*
+ * System level information
+ */
+ return 0;
+ default:
+ return -EINVAL;
+ }
+
+ return smk_curacc(ssp, may);
+}
+
+/**
+ * smack_sem_semop - Smack checks of semaphore operations
+ * @sma: the object
+ * @sops: unused
+ * @nsops: unused
+ * @alter: unused
+ *
+ * Treated as read and write in all cases.
+ *
+ * Returns 0 if access is allowed, error code otherwise
+ */
+static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
+ unsigned nsops, int alter)
+{
+ char *ssp = smack_of_sem(sma);
+
+ return smk_curacc(ssp, MAY_READWRITE);
+}
+
+/**
+ * smack_msg_alloc_security - Set the security blob for msg
+ * @msq: the object
+ *
+ * Returns 0
+ */
+static int smack_msg_queue_alloc_security(struct msg_queue *msq)
+{
+ struct kern_ipc_perm *kisp = &msq->q_perm;
+
+ kisp->security = current->security;
+ return 0;
+}
+
+/**
+ * smack_msg_free_security - Clear the security blob for msg
+ * @msq: the object
+ *
+ * Clears the blob pointer
+ */
+static void smack_msg_queue_free_security(struct msg_queue *msq)
+{
+ struct kern_ipc_perm *kisp = &msq->q_perm;
+
+ kisp->security = NULL;
+}
+
+/**
+ * smack_of_msq - the smack pointer for the msq
+ * @msq: the object
+ *
+ * Returns a pointer to the smack value
+ */
+static char *smack_of_msq(struct msg_queue *msq)
+{
+ return (char *)msq->q_perm.security;
+}
+
+/**
+ * smack_msg_queue_associate - Smack access check for msg_queue
+ * @msq: the object
+ * @msqflg: access requested
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
+{
+ char *msp = smack_of_msq(msq);
+ int may;
+
+ may = smack_flags_to_may(msqflg);
+ return smk_curacc(msp, may);
+}
+
+/**
+ * smack_msg_queue_msgctl - Smack access check for msg_queue
+ * @msq: the object
+ * @cmd: what it wants to do
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
+{
+ char *msp = smack_of_msq(msq);
+ int may;
+
+ switch (cmd) {
+ case IPC_STAT:
+ case MSG_STAT:
+ may = MAY_READ;
+ break;
+ case IPC_SET:
+ case IPC_RMID:
+ may = MAY_READWRITE;
+ break;
+ case IPC_INFO:
+ case MSG_INFO:
+ /*
+ * System level information
+ */
+ return 0;
+ default:
+ return -EINVAL;
+ }
+
+ return smk_curacc(msp, may);
+}
+
+/**
+ * smack_msg_queue_msgsnd - Smack access check for msg_queue
+ * @msq: the object
+ * @msg: unused
+ * @msqflg: access requested
+ *
+ * Returns 0 if current has the requested access, error code otherwise
+ */
+static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
+ int msqflg)
+{
+ char *msp = smack_of_msq(msq);
+ int rc;
+
+ rc = smack_flags_to_may(msqflg);
+ return smk_curacc(msp, rc);
+}
+
+/**
+ * smack_msg_queue_msgsnd - Smack access check for msg_queue
+ * @msq: the object
+ * @msg: unused
+ * @target: unused
+ * @type: unused
+ * @mode: unused
+ *
+ * Returns 0 if current has read and write access, error code otherwise
+ */
+static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
+ struct task_struct *target, long type, int mode)
+{
+ char *msp = smack_of_msq(msq);
+
+ return smk_curacc(msp, MAY_READWRITE);
+}
+
+/**
+ * smack_ipc_permission - Smack access for ipc_permission()
+ * @ipp: the object permissions
+ * @flag: access requested
+ *
+ * Returns 0 if current has read and write access, error code otherwise
+ */
+static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
+{
+ char *isp = ipp->security;
+ int may;
+
+ may = smack_flags_to_may(flag);
+ return smk_curacc(isp, may);
+}
+
+/**
+ * smack_d_instantiate - Make sure the blob is correct on an inode
+ * @opt_dentry: unused
+ * @inode: the object
+ *
+ * Set the inode's security blob if it hasn't been done already.
+ */
+static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
+{
+ struct super_block *sbp;
+ struct superblock_smack *sbsp;
+ struct inode_smack *isp;
+ char *csp = current->security;
+ char *fetched;
+ char *final;
+ struct dentry *dp;
+
+ if (inode == NULL)
+ return;
+
+ isp = inode->i_security;
+
+ mutex_lock(&isp->smk_lock);
+ /*
+ * If the inode is already instantiated
+ * take the quick way out
+ */
+ if (isp->smk_flags & SMK_INODE_INSTANT)
+ goto unlockandout;
+
+ sbp = inode->i_sb;
+ sbsp = sbp->s_security;
+ /*
+ * We're going to use the superblock default label
+ * if there's no label on the file.
+ */
+ final = sbsp->smk_default;
+
+ /*
+ * This is pretty hackish.
+ * Casey says that we shouldn't have to do
+ * file system specific code, but it does help
+ * with keeping it simple.
+ */
+ switch (sbp->s_magic) {
+ case SMACK_MAGIC:
+ /*
+ * Casey says that it's a little embarassing
+ * that the smack file system doesn't do
+ * extended attributes.
+ */
+ final = smack_known_star.smk_known;
+ break;
+ case PIPEFS_MAGIC:
+ /*
+ * Casey says pipes are easy (?)
+ */
+ final = smack_known_star.smk_known;
+ break;
+ case DEVPTS_SUPER_MAGIC:
+ /*
+ * devpts seems content with the label of the task.
+ * Programs that change smack have to treat the
+ * pty with respect.
+ */
+ final = csp;
+ break;
+ case SOCKFS_MAGIC:
+ /*
+ * Casey says sockets get the smack of the task.
+ */
+ final = csp;
+ break;
+ case PROC_SUPER_MAGIC:
+ /*
+ * Casey says procfs appears not to care.
+ * The superblock default suffices.
+ */
+ break;
+ case TMPFS_MAGIC:
+ /*
+ * Device labels should come from the filesystem,
+ * but watch out, because they're volitile,
+ * getting recreated on every reboot.
+ */
+ final = smack_known_star.smk_known;
+ /*
+ * No break.
+ *
+ * If a smack value has been set we want to use it,
+ * but since tmpfs isn't giving us the opportunity
+ * to set mount options simulate setting the
+ * superblock default.
+ */
+ default:
+ /*
+ * This isn't an understood special case.
+ * Get the value from the xattr.
+ *
+ * No xattr support means, alas, no SMACK label.
+ * Use the aforeapplied default.
+ * It would be curious if the label of the task
+ * does not match that assigned.
+ */
+ if (inode->i_op->getxattr == NULL)
+ break;
+ /*
+ * Get the dentry for xattr.
+ */
+ if (opt_dentry == NULL) {
+ dp = d_find_alias(inode);
+ if (dp == NULL)
+ break;
+ } else {
+ dp = dget(opt_dentry);
+ if (dp == NULL)
+ break;
+ }
+
+ fetched = smk_fetch(inode, dp);
+ if (fetched != NULL)
+ final = fetched;
+
+ dput(dp);
+ break;
+ }
+
+ if (final == NULL)
+ isp->smk_inode = csp;
+ else
+ isp->smk_inode = final;
+
+ isp->smk_flags |= SMK_INODE_INSTANT;
+
+unlockandout:
+ mutex_unlock(&isp->smk_lock);
+ return;
+}
+
+/**
+ * smack_getprocattr - Smack process attribute access
+ * @p: the object task
+ * @name: the name of the attribute in /proc/.../attr
+ * @value: where to put the result
+ *
+ * Places a copy of the task Smack into value
+ *
+ * Returns the length of the smack label or an error code
+ */
+static int smack_getprocattr(struct task_struct *p, char *name, char **value)
+{
+ char *cp;
+ int slen;
+
+ if (strcmp(name, "current") != 0)
+ return -EINVAL;
+
+ cp = kstrdup(p->security, GFP_KERNEL);
+ if (cp == NULL)
+ return -ENOMEM;
+
+ slen = strlen(cp);
+ *value = cp;
+ return slen;
+}
+
+/**
+ * smack_setprocattr - Smack process attribute setting
+ * @p: the object task
+ * @name: the name of the attribute in /proc/.../attr
+ * @value: the value to set
+ * @size: the size of the value
+ *
+ * Sets the Smack value of the task. Only setting self
+ * is permitted and only with privilege
+ *
+ * Returns the length of the smack label or an error code
+ */
+static int smack_setprocattr(struct task_struct *p, char *name,
+ void *value, size_t size)
+{
+ char *newsmack;
+
+ if (!__capable(p, CAP_MAC_ADMIN))
+ return -EPERM;
+
+ /*
+ * Changing another process' Smack value is too dangerous
+ * and supports no sane use case.
+ */
+ if (p != current)
+ return -EPERM;
+
+ if (value == NULL || size == 0 || size >= SMK_LABELLEN)
+ return -EINVAL;
+
+ if (strcmp(name, "current") != 0)
+ return -EINVAL;
+
+ newsmack = smk_import(value, size);
+ if (newsmack == NULL)
+ return -EINVAL;
+
+ p->security = newsmack;
+ return size;
+}
+
+/**
+ * smack_unix_stream_connect - Smack access on UDS
+ * @sock: one socket
+ * @other: the other socket
+ * @newsk: unused
+ *
+ * Return 0 if a subject with the smack of sock could access
+ * an object with the smack of other, otherwise an error code
+ */
+static int smack_unix_stream_connect(struct socket *sock,
+ struct socket *other, struct sock *newsk)
+{
+ struct inode *sp = SOCK_INODE(sock);
+ struct inode *op = SOCK_INODE(other);
+
+ return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
+}
+
+/**
+ * smack_unix_may_send - Smack access on UDS
+ * @sock: one socket
+ * @other: the other socket
+ *
+ * Return 0 if a subject with the smack of sock could access
+ * an object with the smack of other, otherwise an error code
+ */
+static int smack_unix_may_send(struct socket *sock, struct socket *other)
+{
+ struct inode *sp = SOCK_INODE(sock);
+ struct inode *op = SOCK_INODE(other);
+
+ return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
+}
+
+/**
+ * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat
+ * pair to smack
+ * @sap: netlabel secattr
+ * @sip: where to put the result
+ *
+ * Copies a smack label into sip
+ */
+static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
+{
+ char smack[SMK_LABELLEN];
+ int pcat;
+
+ if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) {
+ /*
+ * If there are flags but no level netlabel isn't
+ * behaving the way we expect it to.
+ *
+ * Without guidance regarding the smack value
+ * for the packet fall back on the network
+ * ambient value.
+ */
+ strncpy(sip, smack_net_ambient, SMK_MAXLEN);
+ return;
+ }
+ /*
+ * Get the categories, if any
+ */
+ memset(smack, '\0', SMK_LABELLEN);
+ if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
+ for (pcat = -1;;) {
+ pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat,
+ pcat + 1);
+ if (pcat < 0)
+ break;
+ smack_catset_bit(pcat, smack);
+ }
+ /*
+ * If it is CIPSO using smack direct mapping
+ * we are already done. WeeHee.
+ */
+ if (sap->attr.mls.lvl == smack_cipso_direct) {
+ memcpy(sip, smack, SMK_MAXLEN);
+ return;
+ }
+ /*
+ * Look it up in the supplied table if it is not a direct mapping.
+ */
+ smack_from_cipso(sap->attr.mls.lvl, smack, sip);
+ return;
+}
+
+/**
+ * smack_socket_sock_rcv_skb - Smack packet delivery access check
+ * @sk: socket
+ * @skb: packet
+ *
+ * Returns 0 if the packet should be delivered, an error code otherwise
+ */
+static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ struct netlbl_lsm_secattr secattr;
+ struct socket_smack *ssp = sk->sk_security;
+ char smack[SMK_LABELLEN];
+ int rc;
+
+ if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
+ return 0;
+
+ /*
+ * Translate what netlabel gave us.
+ */
+ memset(smack, '\0', SMK_LABELLEN);
+ netlbl_secattr_init(&secattr);
+ rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
+ if (rc == 0)
+ smack_from_secattr(&secattr, smack);
+ else
+ strncpy(smack, smack_net_ambient, SMK_MAXLEN);
+ netlbl_secattr_destroy(&secattr);
+ /*
+ * Receiving a packet requires that the other end
+ * be able to write here. Read access is not required.
+ * This is the simplist possible security model
+ * for networking.
+ */
+ return smk_access(smack, ssp->smk_in, MAY_WRITE);
+}
+
+/**
+ * smack_socket_getpeersec_stream - pull in packet label
+ * @sock: the socket
+ * @optval: user's destination
+ * @optlen: size thereof
+ * @len: max thereoe
+ *
+ * returns zero on success, an error code otherwise
+ */
+static int smack_socket_getpeersec_stream(struct socket *sock,
+ char __user *optval,
+ int __user *optlen, unsigned len)
+{
+ struct socket_smack *ssp;
+ int slen;
+ int rc = 0;
+
+ ssp = sock->sk->sk_security;
+ slen = strlen(ssp->smk_packet) + 1;
+
+ if (slen > len)
+ rc = -ERANGE;
+ else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
+ rc = -EFAULT;
+
+ if (put_user(slen, optlen) != 0)
+ rc = -EFAULT;
+
+ return rc;
+}
+
+
+/**
+ * smack_socket_getpeersec_dgram - pull in packet label
+ * @sock: the socket
+ * @skb: packet data
+ * @secid: pointer to where to put the secid of the packet
+ *
+ * Sets the netlabel socket state on sk from parent
+ */
+static int smack_socket_getpeersec_dgram(struct socket *sock,
+ struct sk_buff *skb, u32 *secid)
+
+{
+ struct netlbl_lsm_secattr secattr;
+ struct sock *sk;
+ char smack[SMK_LABELLEN];
+ int family = PF_INET;
+ u32 s;
+ int rc;
+
+ /*
+ * Only works for families with packets.
+ */
+ if (sock != NULL) {
+ sk = sock->sk;
+ if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
+ return 0;
+ family = sk->sk_family;
+ }
+ /*
+ * Translate what netlabel gave us.
+ */
+ memset(smack, '\0', SMK_LABELLEN);
+ netlbl_secattr_init(&secattr);
+ rc = netlbl_skbuff_getattr(skb, family, &secattr);
+ if (rc == 0)
+ smack_from_secattr(&secattr, smack);
+ netlbl_secattr_destroy(&secattr);
+
+ /*
+ * Give up if we couldn't get anything
+ */
+ if (rc != 0)
+ return rc;
+
+ s = smack_to_secid(smack);
+ if (s == 0)
+ return -EINVAL;
+
+ *secid = s;
+ return 0;
+}
+
+/**
+ * smack_sock_graft - graft access state between two sockets
+ * @sk: fresh sock
+ * @parent: donor socket
+ *
+ * Sets the netlabel socket state on sk from parent
+ */
+static void smack_sock_graft(struct sock *sk, struct socket *parent)
+{
+ struct socket_smack *ssp;
+ int rc;
+
+ if (sk == NULL)
+ return;
+
+ if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
+ return;
+
+ ssp = sk->sk_security;
+ ssp->smk_in = current->security;
+ ssp->smk_out = current->security;
+ ssp->smk_packet[0] = '\0';
+
+ rc = smack_netlabel(sk);
+}
+
+/**
+ * smack_inet_conn_request - Smack access check on connect
+ * @sk: socket involved
+ * @skb: packet
+ * @req: unused
+ *
+ * Returns 0 if a task with the packet label could write to
+ * the socket, otherwise an error code
+ */
+static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req)
+{
+ struct netlbl_lsm_secattr skb_secattr;
+ struct socket_smack *ssp = sk->sk_security;
+ char smack[SMK_LABELLEN];
+ int rc;
+
+ if (skb == NULL)
+ return -EACCES;
+
+ memset(smack, '\0', SMK_LABELLEN);
+ netlbl_secattr_init(&skb_secattr);
+ rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
+ if (rc == 0)
+ smack_from_secattr(&skb_secattr, smack);
+ else
+ strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
+ netlbl_secattr_destroy(&skb_secattr);
+ /*
+ * Receiving a packet requires that the other end
+ * be able to write here. Read access is not required.
+ *
+ * If the request is successful save the peer's label
+ * so that SO_PEERCRED can report it.
+ */
+ rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
+ if (rc == 0)
+ strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
+
+ return rc;
+}
+
+/*
+ * Key management security hooks
+ *
+ * Casey has not tested key support very heavily.
+ * The permission check is most likely too restrictive.
+ * If you care about keys please have a look.
+ */
+#ifdef CONFIG_KEYS
+
+/**
+ * smack_key_alloc - Set the key security blob
+ * @key: object
+ * @tsk: the task associated with the key
+ * @flags: unused
+ *
+ * No allocation required
+ *
+ * Returns 0
+ */
+static int smack_key_alloc(struct key *key, struct task_struct *tsk,
+ unsigned long flags)
+{
+ key->security = tsk->security;
+ return 0;
+}
+
+/**
+ * smack_key_free - Clear the key security blob
+ * @key: the object
+ *
+ * Clear the blob pointer
+ */
+static void smack_key_free(struct key *key)
+{
+ key->security = NULL;
+}
+
+/*
+ * smack_key_permission - Smack access on a key
+ * @key_ref: gets to the object
+ * @context: task involved
+ * @perm: unused
+ *
+ * Return 0 if the task has read and write to the object,
+ * an error code otherwise
+ */
+static int smack_key_permission(key_ref_t key_ref,
+ struct task_struct *context, key_perm_t perm)
+{
+ struct key *keyp;
+
+ keyp = key_ref_to_ptr(key_ref);
+ if (keyp == NULL)
+ return -EINVAL;
+ /*
+ * If the key hasn't been initialized give it access so that
+ * it may do so.
+ */
+ if (keyp->security == NULL)
+ return 0;
+ /*
+ * This should not occur
+ */
+ if (context->security == NULL)
+ return -EACCES;
+
+ return smk_access(context->security, keyp->security, MAY_READWRITE);
+}
+#endif /* CONFIG_KEYS */
+
+/*
+ * smack_secid_to_secctx - return the smack label for a secid
+ * @secid: incoming integer
+ * @secdata: destination
+ * @seclen: how long it is
+ *
+ * Exists for networking code.
+ */
+static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+{
+ char *sp = smack_from_secid(secid);
+
+ *secdata = sp;
+ *seclen = strlen(sp);
+ return 0;
+}
+
+/*
+ * smack_release_secctx - don't do anything.
+ * @key_ref: unused
+ * @context: unused
+ * @perm: unused
+ *
+ * Exists to make sure nothing gets done, and properly
+ */
+static void smack_release_secctx(char *secdata, u32 seclen)
+{
+}
+
+static struct security_operations smack_ops = {
+ .ptrace = smack_ptrace,
+ .capget = cap_capget,
+ .capset_check = cap_capset_check,
+ .capset_set = cap_capset_set,
+ .capable = cap_capable,
+ .syslog = smack_syslog,
+ .settime = cap_settime,
+ .vm_enough_memory = cap_vm_enough_memory,
+
+ .bprm_apply_creds = cap_bprm_apply_creds,
+ .bprm_set_security = cap_bprm_set_security,
+ .bprm_secureexec = cap_bprm_secureexec,
+
+ .sb_alloc_security = smack_sb_alloc_security,
+ .sb_free_security = smack_sb_free_security,
+ .sb_copy_data = smack_sb_copy_data,
+ .sb_kern_mount = smack_sb_kern_mount,
+ .sb_statfs = smack_sb_statfs,
+ .sb_mount = smack_sb_mount,
+ .sb_umount = smack_sb_umount,
+
+ .inode_alloc_security = smack_inode_alloc_security,
+ .inode_free_security = smack_inode_free_security,
+ .inode_init_security = smack_inode_init_security,
+ .inode_link = smack_inode_link,
+ .inode_unlink = smack_inode_unlink,
+ .inode_rmdir = smack_inode_rmdir,
+ .inode_rename = smack_inode_rename,
+ .inode_permission = smack_inode_permission,
+ .inode_setattr = smack_inode_setattr,
+ .inode_getattr = smack_inode_getattr,
+ .inode_setxattr = smack_inode_setxattr,
+ .inode_post_setxattr = smack_inode_post_setxattr,
+ .inode_getxattr = smack_inode_getxattr,
+ .inode_removexattr = smack_inode_removexattr,
+ .inode_getsecurity = smack_inode_getsecurity,
+ .inode_setsecurity = smack_inode_setsecurity,
+ .inode_listsecurity = smack_inode_listsecurity,
+
+ .file_permission = smack_file_permission,
+ .file_alloc_security = smack_file_alloc_security,
+ .file_free_security = smack_file_free_security,
+ .file_ioctl = smack_file_ioctl,
+ .file_lock = smack_file_lock,
+ .file_fcntl = smack_file_fcntl,
+ .file_set_fowner = smack_file_set_fowner,
+ .file_send_sigiotask = smack_file_send_sigiotask,
+ .file_receive = smack_file_receive,
+
+ .task_alloc_security = smack_task_alloc_security,
+ .task_free_security = smack_task_free_security,
+ .task_post_setuid = cap_task_post_setuid,
+ .task_setpgid = smack_task_setpgid,
+ .task_getpgid = smack_task_getpgid,
+ .task_getsid = smack_task_getsid,
+ .task_getsecid = smack_task_getsecid,
+ .task_setnice = smack_task_setnice,
+ .task_setioprio = smack_task_setioprio,
+ .task_getioprio = smack_task_getioprio,
+ .task_setscheduler = smack_task_setscheduler,
+ .task_getscheduler = smack_task_getscheduler,
+ .task_movememory = smack_task_movememory,
+ .task_kill = smack_task_kill,
+ .task_wait = smack_task_wait,
+ .task_reparent_to_init = cap_task_reparent_to_init,
+ .task_to_inode = smack_task_to_inode,
+
+ .ipc_permission = smack_ipc_permission,
+
+ .msg_msg_alloc_security = smack_msg_msg_alloc_security,
+ .msg_msg_free_security = smack_msg_msg_free_security,
+
+ .msg_queue_alloc_security = smack_msg_queue_alloc_security,
+ .msg_queue_free_security = smack_msg_queue_free_security,
+ .msg_queue_associate = smack_msg_queue_associate,
+ .msg_queue_msgctl = smack_msg_queue_msgctl,
+ .msg_queue_msgsnd = smack_msg_queue_msgsnd,
+ .msg_queue_msgrcv = smack_msg_queue_msgrcv,
+
+ .shm_alloc_security = smack_shm_alloc_security,
+ .shm_free_security = smack_shm_free_security,
+ .shm_associate = smack_shm_associate,
+ .shm_shmctl = smack_shm_shmctl,
+ .shm_shmat = smack_shm_shmat,
+
+ .sem_alloc_security = smack_sem_alloc_security,
+ .sem_free_security = smack_sem_free_security,
+ .sem_associate = smack_sem_associate,
+ .sem_semctl = smack_sem_semctl,
+ .sem_semop = smack_sem_semop,
+
+ .netlink_send = cap_netlink_send,
+ .netlink_recv = cap_netlink_recv,
+
+ .d_instantiate = smack_d_instantiate,
+
+ .getprocattr = smack_getprocattr,
+ .setprocattr = smack_setprocattr,
+
+ .unix_stream_connect = smack_unix_stream_connect,
+ .unix_may_send = smack_unix_may_send,
+
+ .socket_post_create = smack_socket_post_create,
+ .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
+ .socket_getpeersec_stream = smack_socket_getpeersec_stream,
+ .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
+ .sk_alloc_security = smack_sk_alloc_security,
+ .sk_free_security = smack_sk_free_security,
+ .sock_graft = smack_sock_graft,
+ .inet_conn_request = smack_inet_conn_request,
+ /* key management security hooks */
+#ifdef CONFIG_KEYS
+ .key_alloc = smack_key_alloc,
+ .key_free = smack_key_free,
+ .key_permission = smack_key_permission,
+#endif /* CONFIG_KEYS */
+ .secid_to_secctx = smack_secid_to_secctx,
+ .release_secctx = smack_release_secctx,
+};
+
+/**
+ * smack_init - initialize the smack system
+ *
+ * Returns 0
+ */
+static __init int smack_init(void)
+{
+ printk(KERN_INFO "Smack: Initializing.\n");
+
+ /*
+ * Set the security state for the initial task.
+ */
+ current->security = &smack_known_floor.smk_known;
+
+ /*
+ * Initialize locks
+ */
+ spin_lock_init(&smack_known_unset.smk_cipsolock);
+ spin_lock_init(&smack_known_huh.smk_cipsolock);
+ spin_lock_init(&smack_known_hat.smk_cipsolock);
+ spin_lock_init(&smack_known_star.smk_cipsolock);
+ spin_lock_init(&smack_known_floor.smk_cipsolock);
+ spin_lock_init(&smack_known_invalid.smk_cipsolock);
+
+ /*
+ * Register with LSM
+ */
+ if (register_security(&smack_ops))
+ panic("smack: Unable to register with kernel.\n");
+
+ return 0;
+}
+
+/*
+ * Smack requires early initialization in order to label
+ * all processes and objects when they are created.
+ */
+security_initcall(smack_init);
+

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