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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 0000000..1c11e42 --- /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 + * + * 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); + |
