diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/errno.h | 1 | ||||
| -rw-r--r-- | include/linux/fs.h | 14 | ||||
| -rw-r--r-- | include/linux/fs_context.h | 188 | ||||
| -rw-r--r-- | include/linux/fs_parser.h | 151 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 39 | ||||
| -rw-r--r-- | include/linux/lsm_hooks.h | 21 | ||||
| -rw-r--r-- | include/linux/mount.h | 3 | ||||
| -rw-r--r-- | include/linux/security.h | 18 |
8 files changed, 412 insertions, 23 deletions
diff --git a/include/linux/errno.h b/include/linux/errno.h index 3cba627577d6..d73f597a2484 100644 --- a/include/linux/errno.h +++ b/include/linux/errno.h @@ -18,6 +18,7 @@ #define ERESTART_RESTARTBLOCK 516 /* restart by calling sys_restart_syscall */ #define EPROBE_DEFER 517 /* Driver requests probe retry */ #define EOPENSTALE 518 /* open found a stale dentry */ +#define ENOPARAM 519 /* Parameter not supported */ /* Defined for the NFSv3 protocol */ #define EBADHANDLE 521 /* Illegal NFS file handle */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 80c6a4093b46..8b42df09b04c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -64,6 +64,8 @@ struct workqueue_struct; struct iov_iter; struct fscrypt_info; struct fscrypt_operations; +struct fs_context; +struct fs_parameter_description; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -1349,6 +1351,7 @@ extern int send_sigurg(struct fown_struct *fown); /* These sb flags are internal to the kernel */ #define SB_SUBMOUNT (1<<26) +#define SB_FORCE (1<<27) #define SB_NOSEC (1<<28) #define SB_BORN (1<<29) #define SB_ACTIVE (1<<30) @@ -1459,7 +1462,7 @@ struct super_block { * Filesystem subtype. If non-empty the filesystem type field * in /proc/mounts will be "type.subtype" */ - char *s_subtype; + const char *s_subtype; const struct dentry_operations *s_d_op; /* default d_op for dentries */ @@ -2170,6 +2173,8 @@ struct file_system_type { #define FS_HAS_SUBTYPE 4 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ + int (*init_fs_context)(struct fs_context *); + const struct fs_parameter_description *parameters; struct dentry *(*mount) (struct file_system_type *, int, const char *, void *); void (*kill_sb) (struct super_block *); @@ -2225,8 +2230,12 @@ void kill_litter_super(struct super_block *sb); void deactivate_super(struct super_block *sb); void deactivate_locked_super(struct super_block *sb); int set_anon_super(struct super_block *s, void *data); +int set_anon_super_fc(struct super_block *s, struct fs_context *fc); int get_anon_bdev(dev_t *); void free_anon_bdev(dev_t); +struct super_block *sget_fc(struct fs_context *fc, + int (*test)(struct super_block *, struct fs_context *), + int (*set)(struct super_block *, struct fs_context *)); struct super_block *sget_userns(struct file_system_type *type, int (*test)(struct super_block *,void *), int (*set)(struct super_block *,void *), @@ -2269,8 +2278,7 @@ mount_pseudo(struct file_system_type *fs_type, char *name, extern int register_filesystem(struct file_system_type *); extern int unregister_filesystem(struct file_system_type *); -extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data); -#define kern_mount(type) kern_mount_data(type, NULL) +extern struct vfsmount *kern_mount(struct file_system_type *); extern void kern_unmount(struct vfsmount *mnt); extern int may_umount_tree(struct vfsmount *); extern int may_umount(struct vfsmount *); diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h new file mode 100644 index 000000000000..eaca452088fa --- /dev/null +++ b/include/linux/fs_context.h @@ -0,0 +1,188 @@ +/* Filesystem superblock creation and reconfiguration context. + * + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _LINUX_FS_CONTEXT_H +#define _LINUX_FS_CONTEXT_H + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/security.h> + +struct cred; +struct dentry; +struct file_operations; +struct file_system_type; +struct mnt_namespace; +struct net; +struct pid_namespace; +struct super_block; +struct user_namespace; +struct vfsmount; +struct path; + +enum fs_context_purpose { + FS_CONTEXT_FOR_MOUNT, /* New superblock for explicit mount */ + FS_CONTEXT_FOR_SUBMOUNT, /* New superblock for automatic submount */ + FS_CONTEXT_FOR_RECONFIGURE, /* Superblock reconfiguration (remount) */ +}; + +/* + * Type of parameter value. + */ +enum fs_value_type { + fs_value_is_undefined, + fs_value_is_flag, /* Value not given a value */ + fs_value_is_string, /* Value is a string */ + fs_value_is_blob, /* Value is a binary blob */ + fs_value_is_filename, /* Value is a filename* + dirfd */ + fs_value_is_filename_empty, /* Value is a filename* + dirfd + AT_EMPTY_PATH */ + fs_value_is_file, /* Value is a file* */ +}; + +/* + * Configuration parameter. + */ +struct fs_parameter { + const char *key; /* Parameter name */ + enum fs_value_type type:8; /* The type of value here */ + union { + char *string; + void *blob; + struct filename *name; + struct file *file; + }; + size_t size; + int dirfd; +}; + +/* + * Filesystem context for holding the parameters used in the creation or + * reconfiguration of a superblock. + * + * Superblock creation fills in ->root whereas reconfiguration begins with this + * already set. + * + * See Documentation/filesystems/mounting.txt + */ +struct fs_context { + const struct fs_context_operations *ops; + struct file_system_type *fs_type; + void *fs_private; /* The filesystem's context */ + struct dentry *root; /* The root and superblock */ + struct user_namespace *user_ns; /* The user namespace for this mount */ + struct net *net_ns; /* The network namespace for this mount */ + const struct cred *cred; /* The mounter's credentials */ + const char *source; /* The source name (eg. dev path) */ + const char *subtype; /* The subtype to set on the superblock */ + void *security; /* Linux S&M options */ + void *s_fs_info; /* Proposed s_fs_info */ + unsigned int sb_flags; /* Proposed superblock flags (SB_*) */ + unsigned int sb_flags_mask; /* Superblock flags that were changed */ + unsigned int lsm_flags; /* Information flags from the fs to the LSM */ + enum fs_context_purpose purpose:8; + bool need_free:1; /* Need to call ops->free() */ + bool global:1; /* Goes into &init_user_ns */ +}; + +struct fs_context_operations { + void (*free)(struct fs_context *fc); + int (*dup)(struct fs_context *fc, struct fs_context *src_fc); + int (*parse_param)(struct fs_context *fc, struct fs_parameter *param); + int (*parse_monolithic)(struct fs_context *fc, void *data); + int (*get_tree)(struct fs_context *fc); + int (*reconfigure)(struct fs_context *fc); +}; + +/* + * fs_context manipulation functions. + */ +extern struct fs_context *fs_context_for_mount(struct file_system_type *fs_type, + unsigned int sb_flags); +extern struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, + unsigned int sb_flags, + unsigned int sb_flags_mask); +extern struct fs_context *fs_context_for_submount(struct file_system_type *fs_type, + struct dentry *reference); + +extern struct fs_context *vfs_dup_fs_context(struct fs_context *fc); +extern int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param); +extern int vfs_parse_fs_string(struct fs_context *fc, const char *key, + const char *value, size_t v_size); +extern int generic_parse_monolithic(struct fs_context *fc, void *data); +extern int vfs_get_tree(struct fs_context *fc); +extern void put_fs_context(struct fs_context *fc); + +/* + * sget() wrapper to be called from the ->get_tree() op. + */ +enum vfs_get_super_keying { + vfs_get_single_super, /* Only one such superblock may exist */ + vfs_get_keyed_super, /* Superblocks with different s_fs_info keys may exist */ + vfs_get_independent_super, /* Multiple independent superblocks may exist */ +}; +extern int vfs_get_super(struct fs_context *fc, + enum vfs_get_super_keying keying, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc)); + +extern const struct file_operations fscontext_fops; + +#ifdef CONFIG_PRINTK +extern __attribute__((format(printf, 2, 3))) +void logfc(struct fs_context *fc, const char *fmt, ...); +#else +static inline __attribute__((format(printf, 2, 3))) +void logfc(struct fs_context *fc, const char *fmt, ...) +{ +} +#endif + +/** + * infof - Store supplementary informational message + * @fc: The context in which to log the informational message + * @fmt: The format string + * + * Store the supplementary informational message for the process if the process + * has enabled the facility. + */ +#define infof(fc, fmt, ...) ({ logfc(fc, "i "fmt, ## __VA_ARGS__); }) + +/** + * warnf - Store supplementary warning message + * @fc: The context in which to log the error message + * @fmt: The format string + * + * Store the supplementary warning message for the process if the process has + * enabled the facility. + */ +#define warnf(fc, fmt, ...) ({ logfc(fc, "w "fmt, ## __VA_ARGS__); }) + +/** + * errorf - Store supplementary error message + * @fc: The context in which to log the error message + * @fmt: The format string + * + * Store the supplementary error message for the process if the process has + * enabled the facility. + */ +#define errorf(fc, fmt, ...) ({ logfc(fc, "e "fmt, ## __VA_ARGS__); }) + +/** + * invalf - Store supplementary invalid argument error message + * @fc: The context in which to log the error message + * @fmt: The format string + * + * Store the supplementary error message for the process if the process has + * enabled the facility and return -EINVAL. + */ +#define invalf(fc, fmt, ...) ({ errorf(fc, fmt, ## __VA_ARGS__); -EINVAL; }) + +#endif /* _LINUX_FS_CONTEXT_H */ diff --git a/include/linux/fs_parser.h b/include/linux/fs_parser.h new file mode 100644 index 000000000000..d966f96ffe62 --- /dev/null +++ b/include/linux/fs_parser.h @@ -0,0 +1,151 @@ +/* Filesystem parameter description and parser + * + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _LINUX_FS_PARSER_H +#define _LINUX_FS_PARSER_H + +#include <linux/fs_context.h> + +struct path; + +struct constant_table { + const char *name; + int value; +}; + +/* + * The type of parameter expected. + */ +enum fs_parameter_type { + __fs_param_wasnt_defined, + fs_param_is_flag, + fs_param_is_bool, + fs_param_is_u32, + fs_param_is_u32_octal, + fs_param_is_u32_hex, + fs_param_is_s32, + fs_param_is_u64, + fs_param_is_enum, + fs_param_is_string, + fs_param_is_blob, + fs_param_is_blockdev, + fs_param_is_path, + fs_param_is_fd, + nr__fs_parameter_type, +}; + +/* + * Specification of the type of value a parameter wants. + * + * Note that the fsparam_flag(), fsparam_string(), fsparam_u32(), ... macros + * should be used to generate elements of this type. + */ +struct fs_parameter_spec { + const char *name; + u8 opt; /* Option number (returned by fs_parse()) */ + enum fs_parameter_type type:8; /* The desired parameter type */ + unsigned short flags; +#define fs_param_v_optional 0x0001 /* The value is optional */ +#define fs_param_neg_with_no 0x0002 /* "noxxx" is negative param */ +#define fs_param_neg_with_empty 0x0004 /* "xxx=" is negative param */ +#define fs_param_deprecated 0x0008 /* The param is deprecated */ +}; + +struct fs_parameter_enum { + u8 opt; /* Option number (as fs_parameter_spec::opt) */ + char name[14]; + u8 value; +}; + +struct fs_parameter_description { + const char name[16]; /* Name for logging purposes */ + const struct fs_parameter_spec *specs; /* List of param specifications */ + const struct fs_parameter_enum *enums; /* Enum values */ +}; + +/* + * Result of parse. + */ +struct fs_parse_result { + bool negated; /* T if param was "noxxx" */ + bool has_value; /* T if value supplied to param */ + union { + bool boolean; /* For spec_bool */ + int int_32; /* For spec_s32/spec_enum */ + unsigned int uint_32; /* For spec_u32{,_octal,_hex}/spec_enum */ + u64 uint_64; /* For spec_u64 */ + }; +}; + +extern int fs_parse(struct fs_context *fc, + const struct fs_parameter_description *desc, + struct fs_parameter *value, + struct fs_parse_result *result); +extern int fs_lookup_param(struct fs_context *fc, + struct fs_parameter *param, + bool want_bdev, + struct path *_path); + +extern int __lookup_constant(const struct constant_table tbl[], size_t tbl_size, + const char *name, int not_found); +#define lookup_constant(t, n, nf) __lookup_constant(t, ARRAY_SIZE(t), (n), (nf)) + +#ifdef CONFIG_VALIDATE_FS_PARSER +extern bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, + int low, int high, int special); +extern bool fs_validate_description(const struct fs_parameter_description *desc); +#else +static inline bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, + int low, int high, int special) +{ return true; } +static inline bool fs_validate_description(const struct fs_parameter_description *desc) +{ return true; } +#endif + +/* + * Parameter type, name, index and flags element constructors. Use as: + * + * fsparam_xxxx("foo", Opt_foo) + * + * If existing helpers are not enough, direct use of __fsparam() would + * work, but any such case is probably a sign that new helper is needed. + * Helpers will remain stable; low-level implementation may change. + */ +#define __fsparam(TYPE, NAME, OPT, FLAGS) \ + { \ + .name = NAME, \ + .opt = OPT, \ + .type = TYPE, \ + .flags = FLAGS \ + } + +#define fsparam_flag(NAME, OPT) __fsparam(fs_param_is_flag, NAME, OPT, 0) +#define fsparam_flag_no(NAME, OPT) \ + __fsparam(fs_param_is_flag, NAME, OPT, \ + fs_param_neg_with_no) +#define fsparam_bool(NAME, OPT) __fsparam(fs_param_is_bool, NAME, OPT, 0) +#define fsparam_u32(NAME, OPT) __fsparam(fs_param_is_u32, NAME, OPT, 0) +#define fsparam_u32oct(NAME, OPT) \ + __fsparam(fs_param_is_u32_octal, NAME, OPT, 0) +#define fsparam_u32hex(NAME, OPT) \ + __fsparam(fs_param_is_u32_hex, NAME, OPT, 0) +#define fsparam_s32(NAME, OPT) __fsparam(fs_param_is_s32, NAME, OPT, 0) +#define fsparam_u64(NAME, OPT) __fsparam(fs_param_is_u64, NAME, OPT, 0) +#define fsparam_enum(NAME, OPT) __fsparam(fs_param_is_enum, NAME, OPT, 0) +#define fsparam_string(NAME, OPT) \ + __fsparam(fs_param_is_string, NAME, OPT, 0) +#define fsparam_blob(NAME, OPT) __fsparam(fs_param_is_blob, NAME, OPT, 0) +#define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0) +#define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0) +#define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0) + + +#endif /* _LINUX_FS_PARSER_H */ diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 0cac1207bb00..c8893f663470 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -26,7 +26,9 @@ struct vm_area_struct; struct super_block; struct file_system_type; struct poll_table_struct; +struct fs_context; +struct kernfs_fs_context; struct kernfs_open_node; struct kernfs_iattrs; @@ -168,7 +170,6 @@ struct kernfs_node { * kernfs_node parameter. */ struct kernfs_syscall_ops { - int (*remount_fs)(struct kernfs_root *root, int *flags, char *data); int (*show_options)(struct seq_file *sf, struct kernfs_root *root); int (*mkdir)(struct kernfs_node *parent, const char *name, @@ -272,6 +273,18 @@ struct kernfs_ops { #endif }; +/* + * The kernfs superblock creation/mount parameter context. + */ +struct kernfs_fs_context { + struct kernfs_root *root; /* Root of the hierarchy being mounted */ + void *ns_tag; /* Namespace tag of the mount (or NULL) */ + unsigned long magic; /* File system specific magic number */ + + /* The following are set/used by kernfs_mount() */ + bool new_sb_created; /* Set to T if we allocated a new sb */ +}; + #ifdef CONFIG_KERNFS static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) @@ -359,11 +372,9 @@ __poll_t kernfs_generic_poll(struct kernfs_open_file *of, void kernfs_notify(struct kernfs_node *kn); const void *kernfs_super_ns(struct super_block *sb); -struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, unsigned long magic, - bool *new_sb_created, const void *ns); +int kernfs_get_tree(struct fs_context *fc); +void kernfs_free_fs_context(struct fs_context *fc); void kernfs_kill_sb(struct super_block *sb); -struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns); void kernfs_init(void); @@ -465,11 +476,10 @@ static inline void kernfs_notify(struct kernfs_node *kn) { } static inline const void *kernfs_super_ns(struct super_block *sb) { return NULL; } -static inline struct dentry * -kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, unsigned long magic, - bool *new_sb_created, const void *ns) -{ return ERR_PTR(-ENOSYS); } +static inline int kernfs_get_tree(struct fs_context *fc) +{ return -ENOSYS; } + +static inline void kernfs_free_fs_context(struct fs_context *fc) { } static inline void kernfs_kill_sb(struct super_block *sb) { } @@ -552,13 +562,4 @@ static inline int kernfs_rename(struct kernfs_node *kn, return kernfs_rename_ns(kn, new_parent, new_name, NULL); } -static inline struct dentry * -kernfs_mount(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, unsigned long magic, - bool *new_sb_created) -{ - return kernfs_mount_ns(fs_type, flags, root, - magic, new_sb_created, NULL); -} - #endif /* __LINUX_KERNFS_H */ diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 85a301632cf1..a9b8ff578b6b 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -76,6 +76,22 @@ * changes on the process such as clearing out non-inheritable signal * state. This is called immediately after commit_creds(). * + * Security hooks for mount using fs_context. + * [See also Documentation/filesystems/mounting.txt] + * + * @fs_context_dup: + * Allocate and attach a security structure to sc->security. This pointer + * is initialised to NULL by the caller. + * @fc indicates the new filesystem context. + * @src_fc indicates the original filesystem context. + * @fs_context_parse_param: + * Userspace provided a parameter to configure a superblock. The LSM may + * reject it with an error and may use it for itself, in which case it + * should return 0; otherwise it should return -ENOPARAM to pass it on to + * the filesystem. + * @fc indicates the filesystem context. + * @param The parameter + * * Security hooks for filesystem operations. * * @sb_alloc_security: @@ -1460,6 +1476,9 @@ union security_list_options { void (*bprm_committing_creds)(struct linux_binprm *bprm); void (*bprm_committed_creds)(struct linux_binprm *bprm); + int (*fs_context_dup)(struct fs_context *fc, struct fs_context *src_sc); + int (*fs_context_parse_param)(struct fs_context *fc, struct fs_parameter *param); + int (*sb_alloc_security)(struct super_block *sb); void (*sb_free_security)(struct super_block *sb); void (*sb_free_mnt_opts)(void *mnt_opts); @@ -1800,6 +1819,8 @@ struct security_hook_heads { struct hlist_head bprm_check_security; struct hlist_head bprm_committing_creds; struct hlist_head bprm_committed_creds; + struct hlist_head fs_context_dup; + struct hlist_head fs_context_parse_param; struct hlist_head sb_alloc_security; struct hlist_head sb_free_security; struct hlist_head sb_free_mnt_opts; diff --git a/include/linux/mount.h b/include/linux/mount.h index 037eed52164b..9197ddbf35fb 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -21,6 +21,7 @@ struct super_block; struct vfsmount; struct dentry; struct mnt_namespace; +struct fs_context; #define MNT_NOSUID 0x01 #define MNT_NODEV 0x02 @@ -88,6 +89,8 @@ struct path; extern struct vfsmount *clone_private_mount(const struct path *path); struct file_system_type; +extern struct vfsmount *fc_mount(struct fs_context *fc); +extern struct vfsmount *vfs_create_mount(struct fs_context *fc); extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data); diff --git a/include/linux/security.h b/include/linux/security.h index 2b35a43d11d6..49f2685324b0 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -53,6 +53,9 @@ struct msg_msg; struct xattr; struct xfrm_sec_ctx; struct mm_struct; +struct fs_context; +struct fs_parameter; +enum fs_value_type; /* Default (no) options for the capable function */ #define CAP_OPT_NONE 0x0 @@ -61,7 +64,7 @@ struct mm_struct; /* If capable is being called by a setid function */ #define CAP_OPT_INSETID BIT(2) -/* LSM Agnostic defines for sb_set_mnt_opts */ +/* LSM Agnostic defines for fs_context::lsm_flags */ #define SECURITY_LSM_NATIVE_LABELS 1 struct ctl_table; @@ -223,6 +226,8 @@ int security_bprm_set_creds(struct linux_binprm *bprm); int security_bprm_check(struct linux_binprm *bprm); void security_bprm_committing_creds(struct linux_binprm *bprm); void security_bprm_committed_creds(struct linux_binprm *bprm); +int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc); +int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param); int security_sb_alloc(struct super_block *sb); void security_sb_free(struct super_block *sb); void security_free_mnt_opts(void **mnt_opts); @@ -519,6 +524,17 @@ static inline void security_bprm_committed_creds(struct linux_binprm *bprm) { } +static inline int security_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + return 0; +} +static inline int security_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + return -ENOPARAM; +} + static inline int security_sb_alloc(struct super_block *sb) { return 0; |