diff options
Diffstat (limited to 'security/tomoyo/tomoyo.c')
-rw-r--r-- | security/tomoyo/tomoyo.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c new file mode 100644 index 0000000..3eeeae1 --- /dev/null +++ b/security/tomoyo/tomoyo.c @@ -0,0 +1,294 @@ +/* + * security/tomoyo/tomoyo.c + * + * LSM hooks for TOMOYO Linux. + * + * Copyright (C) 2005-2009 NTT DATA CORPORATION + * + * Version: 2.2.0-pre 2009/02/01 + * + */ + +#include <linux/security.h> +#include "common.h" +#include "tomoyo.h" +#include "realpath.h" + +static int tomoyo_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + /* + * Since "struct tomoyo_domain_info *" is a sharable pointer, + * we don't need to duplicate. + */ + new->security = old->security; + return 0; +} + +static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) +{ + /* + * Do only if this function is called for the first time of an execve + * operation. + */ + if (bprm->cred_prepared) + return 0; + /* + * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested + * for the first time. + */ + if (!tomoyo_policy_loaded) + tomoyo_load_policy(bprm->filename); + /* + * Tell tomoyo_bprm_check_security() is called for the first time of an + * execve operation. + */ + bprm->cred->security = NULL; + return 0; +} + +static int tomoyo_bprm_check_security(struct linux_binprm *bprm) +{ + struct tomoyo_domain_info *domain = bprm->cred->security; + + /* + * Execute permission is checked against pathname passed to do_execve() + * using current domain. + */ + if (!domain) { + struct tomoyo_domain_info *next_domain = NULL; + int retval = tomoyo_find_next_domain(bprm, &next_domain); + + if (!retval) + bprm->cred->security = next_domain; + return retval; + } + /* + * Read permission is checked against interpreters using next domain. + * '1' is the result of open_to_namei_flags(O_RDONLY). + */ + return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1); +} + +#ifdef CONFIG_SYSCTL + +static int tomoyo_prepend(char **buffer, int *buflen, const char *str) +{ + int namelen = strlen(str); + + if (*buflen < namelen) + return -ENOMEM; + *buflen -= namelen; + *buffer -= namelen; + memcpy(*buffer, str, namelen); + return 0; +} + +/** + * tomoyo_sysctl_path - return the realpath of a ctl_table. + * @table: pointer to "struct ctl_table". + * + * Returns realpath(3) of the @table on success. + * Returns NULL on failure. + * + * This function uses tomoyo_alloc(), so the caller must call tomoyo_free() + * if this function didn't return NULL. + */ +static char *tomoyo_sysctl_path(struct ctl_table *table) +{ + int buflen = TOMOYO_MAX_PATHNAME_LEN; + char *buf = tomoyo_alloc(buflen); + char *end = buf + buflen; + int error = -ENOMEM; + + if (!buf) + return NULL; + + *--end = '\0'; + buflen--; + while (table) { + char num[32]; + const char *sp = table->procname; + + if (!sp) { + memset(num, 0, sizeof(num)); + snprintf(num, sizeof(num) - 1, "=%d=", table->ctl_name); + sp = num; + } + if (tomoyo_prepend(&end, &buflen, sp) || + tomoyo_prepend(&end, &buflen, "/")) + goto out; + table = table->parent; + } + if (tomoyo_prepend(&end, &buflen, "/proc/sys")) + goto out; + error = tomoyo_encode(buf, end - buf, end); + out: + if (!error) + return buf; + tomoyo_free(buf); + return NULL; +} + +static int tomoyo_sysctl(struct ctl_table *table, int op) +{ + int error; + char *name; + + op &= MAY_READ | MAY_WRITE; + if (!op) + return 0; + name = tomoyo_sysctl_path(table); + if (!name) + return -ENOMEM; + error = tomoyo_check_file_perm(tomoyo_domain(), name, op); + tomoyo_free(name); + return error; +} +#endif + +static int tomoyo_path_truncate(struct path *path, loff_t length, + unsigned int time_attrs) +{ + return tomoyo_check_1path_perm(tomoyo_domain(), + TOMOYO_TYPE_TRUNCATE_ACL, + path); +} + +static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry) +{ + struct path path = { parent->mnt, dentry }; + return tomoyo_check_1path_perm(tomoyo_domain(), + TOMOYO_TYPE_UNLINK_ACL, + &path); +} + +static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry, + int mode) +{ + struct path path = { parent->mnt, dentry }; + return tomoyo_check_1path_perm(tomoyo_domain(), + TOMOYO_TYPE_MKDIR_ACL, + &path); +} + +static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry) +{ + struct path path = { parent->mnt, dentry }; + return tomoyo_check_1path_perm(tomoyo_domain(), + TOMOYO_TYPE_RMDIR_ACL, + &path); +} + +static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry, + const char *old_name) +{ + struct path path = { parent->mnt, dentry }; + return tomoyo_check_1path_perm(tomoyo_domain(), + TOMOYO_TYPE_SYMLINK_ACL, + &path); +} + +static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry, + int mode, unsigned int dev) +{ + struct path path = { parent->mnt, dentry }; + int type = TOMOYO_TYPE_CREATE_ACL; + + switch (mode & S_IFMT) { + case S_IFCHR: + type = TOMOYO_TYPE_MKCHAR_ACL; + break; + case S_IFBLK: + type = TOMOYO_TYPE_MKBLOCK_ACL; + break; + case S_IFIFO: + type = TOMOYO_TYPE_MKFIFO_ACL; + break; + case S_IFSOCK: + type = TOMOYO_TYPE_MKSOCK_ACL; + break; + } + return tomoyo_check_1path_perm(tomoyo_domain(), + type, &path); +} + +static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir, + struct dentry *new_dentry) +{ + struct path path1 = { new_dir->mnt, old_dentry }; + struct path path2 = { new_dir->mnt, new_dentry }; + return tomoyo_check_2path_perm(tomoyo_domain(), + TOMOYO_TYPE_LINK_ACL, + &path1, &path2); +} + +static int tomoyo_path_rename(struct path *old_parent, + struct dentry *old_dentry, + struct path *new_parent, + struct dentry *new_dentry) +{ + struct path path1 = { old_parent->mnt, old_dentry }; + struct path path2 = { new_parent->mnt, new_dentry }; + return tomoyo_check_2path_perm(tomoyo_domain(), + TOMOYO_TYPE_RENAME_ACL, + &path1, &path2); +} + +static int tomoyo_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)) + return tomoyo_check_rewrite_permission(tomoyo_domain(), file); + return 0; +} + +static int tomoyo_dentry_open(struct file *f, const struct cred *cred) +{ + int flags = f->f_flags; + + if ((flags + 1) & O_ACCMODE) + flags++; + flags |= f->f_flags & (O_APPEND | O_TRUNC); + /* Don't check read permission here if called from do_execve(). */ + if (current->in_execve) + return 0; + return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags); +} + +static struct security_operations tomoyo_security_ops = { + .name = "tomoyo", + .cred_prepare = tomoyo_cred_prepare, + .bprm_set_creds = tomoyo_bprm_set_creds, + .bprm_check_security = tomoyo_bprm_check_security, +#ifdef CONFIG_SYSCTL + .sysctl = tomoyo_sysctl, +#endif + .file_fcntl = tomoyo_file_fcntl, + .dentry_open = tomoyo_dentry_open, + .path_truncate = tomoyo_path_truncate, + .path_unlink = tomoyo_path_unlink, + .path_mkdir = tomoyo_path_mkdir, + .path_rmdir = tomoyo_path_rmdir, + .path_symlink = tomoyo_path_symlink, + .path_mknod = tomoyo_path_mknod, + .path_link = tomoyo_path_link, + .path_rename = tomoyo_path_rename, +}; + +static int __init tomoyo_init(void) +{ + struct cred *cred = (struct cred *) current_cred(); + + if (!security_module_enable(&tomoyo_security_ops)) + return 0; + /* register ourselves with the security framework */ + if (register_security(&tomoyo_security_ops)) + panic("Failure registering TOMOYO Linux"); + printk(KERN_INFO "TOMOYO Linux initialized\n"); + cred->security = &tomoyo_kernel_domain; + tomoyo_realpath_init(); + return 0; +} + +security_initcall(tomoyo_init); |