diff options
Diffstat (limited to 'ANDROID_3.4.5/security/apparmor/apparmorfs.c')
-rw-r--r-- | ANDROID_3.4.5/security/apparmor/apparmorfs.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/security/apparmor/apparmorfs.c b/ANDROID_3.4.5/security/apparmor/apparmorfs.c new file mode 100644 index 00000000..16c15ec6 --- /dev/null +++ b/ANDROID_3.4.5/security/apparmor/apparmorfs.c @@ -0,0 +1,355 @@ +/* + * AppArmor security module + * + * This file contains AppArmor /sys/kernel/security/apparmor interface functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + */ + +#include <linux/security.h> +#include <linux/vmalloc.h> +#include <linux/module.h> +#include <linux/seq_file.h> +#include <linux/uaccess.h> +#include <linux/namei.h> +#include <linux/capability.h> + +#include "include/apparmor.h" +#include "include/apparmorfs.h" +#include "include/audit.h" +#include "include/context.h" +#include "include/policy.h" +#include "include/resource.h" + +/** + * aa_simple_write_to_buffer - common routine for getting policy from user + * @op: operation doing the user buffer copy + * @userbuf: user buffer to copy data from (NOT NULL) + * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size) + * @copy_size: size of data to copy from user buffer + * @pos: position write is at in the file (NOT NULL) + * + * Returns: kernel buffer containing copy of user buffer data or an + * ERR_PTR on failure. + */ +static char *aa_simple_write_to_buffer(int op, const char __user *userbuf, + size_t alloc_size, size_t copy_size, + loff_t *pos) +{ + char *data; + + BUG_ON(copy_size > alloc_size); + + if (*pos != 0) + /* only writes from pos 0, that is complete writes */ + return ERR_PTR(-ESPIPE); + + /* + * Don't allow profile load/replace/remove from profiles that don't + * have CAP_MAC_ADMIN + */ + if (!aa_may_manage_policy(op)) + return ERR_PTR(-EACCES); + + /* freed by caller to simple_write_to_buffer */ + data = kvmalloc(alloc_size); + if (data == NULL) + return ERR_PTR(-ENOMEM); + + if (copy_from_user(data, userbuf, copy_size)) { + kvfree(data); + return ERR_PTR(-EFAULT); + } + + return data; +} + + +/* .load file hook fn to load policy */ +static ssize_t profile_load(struct file *f, const char __user *buf, size_t size, + loff_t *pos) +{ + char *data; + ssize_t error; + + data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos); + + error = PTR_ERR(data); + if (!IS_ERR(data)) { + error = aa_replace_profiles(data, size, PROF_ADD); + kvfree(data); + } + + return error; +} + +static const struct file_operations aa_fs_profile_load = { + .write = profile_load, + .llseek = default_llseek, +}; + +/* .replace file hook fn to load and/or replace policy */ +static ssize_t profile_replace(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + char *data; + ssize_t error; + + data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos); + error = PTR_ERR(data); + if (!IS_ERR(data)) { + error = aa_replace_profiles(data, size, PROF_REPLACE); + kvfree(data); + } + + return error; +} + +static const struct file_operations aa_fs_profile_replace = { + .write = profile_replace, + .llseek = default_llseek, +}; + +/* .remove file hook fn to remove loaded policy */ +static ssize_t profile_remove(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + char *data; + ssize_t error; + + /* + * aa_remove_profile needs a null terminated string so 1 extra + * byte is allocated and the copied data is null terminated. + */ + data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos); + + error = PTR_ERR(data); + if (!IS_ERR(data)) { + data[size] = 0; + error = aa_remove_profiles(data, size); + kvfree(data); + } + + return error; +} + +static const struct file_operations aa_fs_profile_remove = { + .write = profile_remove, + .llseek = default_llseek, +}; + +static int aa_fs_seq_show(struct seq_file *seq, void *v) +{ + struct aa_fs_entry *fs_file = seq->private; + + if (!fs_file) + return 0; + + switch (fs_file->v_type) { + case AA_FS_TYPE_BOOLEAN: + seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no"); + break; + case AA_FS_TYPE_STRING: + seq_printf(seq, "%s\n", fs_file->v.string); + break; + case AA_FS_TYPE_U64: + seq_printf(seq, "%#08lx\n", fs_file->v.u64); + break; + default: + /* Ignore unpritable entry types. */ + break; + } + + return 0; +} + +static int aa_fs_seq_open(struct inode *inode, struct file *file) +{ + return single_open(file, aa_fs_seq_show, inode->i_private); +} + +const struct file_operations aa_fs_seq_file_ops = { + .owner = THIS_MODULE, + .open = aa_fs_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/** Base file system setup **/ + +static struct aa_fs_entry aa_fs_entry_file[] = { + AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \ + "link lock"), + { } +}; + +static struct aa_fs_entry aa_fs_entry_domain[] = { + AA_FS_FILE_BOOLEAN("change_hat", 1), + AA_FS_FILE_BOOLEAN("change_hatv", 1), + AA_FS_FILE_BOOLEAN("change_onexec", 1), + AA_FS_FILE_BOOLEAN("change_profile", 1), + { } +}; + +static struct aa_fs_entry aa_fs_entry_features[] = { + AA_FS_DIR("domain", aa_fs_entry_domain), + AA_FS_DIR("file", aa_fs_entry_file), + AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK), + AA_FS_DIR("rlimit", aa_fs_entry_rlimit), + { } +}; + +static struct aa_fs_entry aa_fs_entry_apparmor[] = { + AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load), + AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace), + AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove), + AA_FS_DIR("features", aa_fs_entry_features), + { } +}; + +static struct aa_fs_entry aa_fs_entry = + AA_FS_DIR("apparmor", aa_fs_entry_apparmor); + +/** + * aafs_create_file - create a file entry in the apparmor securityfs + * @fs_file: aa_fs_entry to build an entry for (NOT NULL) + * @parent: the parent dentry in the securityfs + * + * Use aafs_remove_file to remove entries created with this fn. + */ +static int __init aafs_create_file(struct aa_fs_entry *fs_file, + struct dentry *parent) +{ + int error = 0; + + fs_file->dentry = securityfs_create_file(fs_file->name, + S_IFREG | fs_file->mode, + parent, fs_file, + fs_file->file_ops); + if (IS_ERR(fs_file->dentry)) { + error = PTR_ERR(fs_file->dentry); + fs_file->dentry = NULL; + } + return error; +} + +/** + * aafs_create_dir - recursively create a directory entry in the securityfs + * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL) + * @parent: the parent dentry in the securityfs + * + * Use aafs_remove_dir to remove entries created with this fn. + */ +static int __init aafs_create_dir(struct aa_fs_entry *fs_dir, + struct dentry *parent) +{ + int error; + struct aa_fs_entry *fs_file; + + fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent); + if (IS_ERR(fs_dir->dentry)) { + error = PTR_ERR(fs_dir->dentry); + fs_dir->dentry = NULL; + goto failed; + } + + for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { + if (fs_file->v_type == AA_FS_TYPE_DIR) + error = aafs_create_dir(fs_file, fs_dir->dentry); + else + error = aafs_create_file(fs_file, fs_dir->dentry); + if (error) + goto failed; + } + + return 0; + +failed: + return error; +} + +/** + * aafs_remove_file - drop a single file entry in the apparmor securityfs + * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL) + */ +static void __init aafs_remove_file(struct aa_fs_entry *fs_file) +{ + if (!fs_file->dentry) + return; + + securityfs_remove(fs_file->dentry); + fs_file->dentry = NULL; +} + +/** + * aafs_remove_dir - recursively drop a directory entry from the securityfs + * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL) + */ +static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir) +{ + struct aa_fs_entry *fs_file; + + for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { + if (fs_file->v_type == AA_FS_TYPE_DIR) + aafs_remove_dir(fs_file); + else + aafs_remove_file(fs_file); + } + + aafs_remove_file(fs_dir); +} + +/** + * aa_destroy_aafs - cleanup and free aafs + * + * releases dentries allocated by aa_create_aafs + */ +void __init aa_destroy_aafs(void) +{ + aafs_remove_dir(&aa_fs_entry); +} + +/** + * aa_create_aafs - create the apparmor security filesystem + * + * dentries created here are released by aa_destroy_aafs + * + * Returns: error on failure + */ +static int __init aa_create_aafs(void) +{ + int error; + + if (!apparmor_initialized) + return 0; + + if (aa_fs_entry.dentry) { + AA_ERROR("%s: AppArmor securityfs already exists\n", __func__); + return -EEXIST; + } + + /* Populate fs tree. */ + error = aafs_create_dir(&aa_fs_entry, NULL); + if (error) + goto error; + + /* TODO: add support for apparmorfs_null and apparmorfs_mnt */ + + /* Report that AppArmor fs is enabled */ + aa_info_message("AppArmor Filesystem Enabled"); + return 0; + +error: + aa_destroy_aafs(); + AA_ERROR("Error creating AppArmor securityfs\n"); + return error; +} + +fs_initcall(aa_create_aafs); |