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Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 2518 |
1 files changed, 2518 insertions, 0 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c new file mode 100644 index 00000000000..1c11e424585 --- /dev/null +++ b/security/smack/smack_lsm.c @@ -0,0 +1,2518 @@ +/* + * 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 + * + * |