fs/ksmbd/smbacl.h

0001 /* SPDX-License-Identifier: LGPL-2.1+ */
0002 /*
0003  *   Copyright (c) International Business Machines  Corp., 2007
0004  *   Author(s): Steve French (sfrench@us.ibm.com)
0005  *   Modified by Namjae Jeon (linkinjeon@kernel.org)
0006  */
0007
0008 #ifndef _SMBACL_H
0009 #define _SMBACL_H
0010
0011 #include <linux/fs.h>
0012 #include <linux/namei.h>
0013 #include <linux/posix_acl.h>
0014 #include <linux/mnt_idmapping.h>
0015
0016 #include "mgmt/tree_connect.h"
0017
0018 #define NUM_AUTHS (6)   /* number of authority fields */
0019 #define SID_MAX_SUB_AUTHORITIES (15) /* max number of sub authority fields */
0020
0021 /*
0022  * ACE types - see MS-DTYP 2.4.4.1
0023  */
0024 enum {
0025     ACCESS_ALLOWED,
0026     ACCESS_DENIED,
0027 };
0028
0029 /*
0030  * Security ID types
0031  */
0032 enum {
0033     SIDOWNER = 1,
0034     SIDGROUP,
0035     SIDCREATOR_OWNER,
0036     SIDCREATOR_GROUP,
0037     SIDUNIX_USER,
0038     SIDUNIX_GROUP,
0039     SIDNFS_USER,
0040     SIDNFS_GROUP,
0041     SIDNFS_MODE,
0042 };
0043
0044 /* Revision for ACLs */
0045 #define SD_REVISION 1
0046
0047 /* Control flags for Security Descriptor */
0048 #define OWNER_DEFAULTED     0x0001
0049 #define GROUP_DEFAULTED     0x0002
0050 #define DACL_PRESENT        0x0004
0051 #define DACL_DEFAULTED      0x0008
0052 #define SACL_PRESENT        0x0010
0053 #define SACL_DEFAULTED      0x0020
0054 #define DACL_TRUSTED        0x0040
0055 #define SERVER_SECURITY     0x0080
0056 #define DACL_AUTO_INHERIT_REQ   0x0100
0057 #define SACL_AUTO_INHERIT_REQ   0x0200
0058 #define DACL_AUTO_INHERITED 0x0400
0059 #define SACL_AUTO_INHERITED 0x0800
0060 #define DACL_PROTECTED      0x1000
0061 #define SACL_PROTECTED      0x2000
0062 #define RM_CONTROL_VALID    0x4000
0063 #define SELF_RELATIVE       0x8000
0064
0065 /* ACE types - see MS-DTYP 2.4.4.1 */
0066 #define ACCESS_ALLOWED_ACE_TYPE 0x00
0067 #define ACCESS_DENIED_ACE_TYPE  0x01
0068 #define SYSTEM_AUDIT_ACE_TYPE   0x02
0069 #define SYSTEM_ALARM_ACE_TYPE   0x03
0070 #define ACCESS_ALLOWED_COMPOUND_ACE_TYPE 0x04
0071 #define ACCESS_ALLOWED_OBJECT_ACE_TYPE  0x05
0072 #define ACCESS_DENIED_OBJECT_ACE_TYPE   0x06
0073 #define SYSTEM_AUDIT_OBJECT_ACE_TYPE    0x07
0074 #define SYSTEM_ALARM_OBJECT_ACE_TYPE    0x08
0075 #define ACCESS_ALLOWED_CALLBACK_ACE_TYPE 0x09
0076 #define ACCESS_DENIED_CALLBACK_ACE_TYPE 0x0A
0077 #define ACCESS_ALLOWED_CALLBACK_OBJECT_ACE_TYPE 0x0B
0078 #define ACCESS_DENIED_CALLBACK_OBJECT_ACE_TYPE  0x0C
0079 #define SYSTEM_AUDIT_CALLBACK_ACE_TYPE  0x0D
0080 #define SYSTEM_ALARM_CALLBACK_ACE_TYPE  0x0E /* Reserved */
0081 #define SYSTEM_AUDIT_CALLBACK_OBJECT_ACE_TYPE 0x0F
0082 #define SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE 0x10 /* reserved */
0083 #define SYSTEM_MANDATORY_LABEL_ACE_TYPE 0x11
0084 #define SYSTEM_RESOURCE_ATTRIBUTE_ACE_TYPE 0x12
0085 #define SYSTEM_SCOPED_POLICY_ID_ACE_TYPE 0x13
0086
0087 /* ACE flags */
0088 #define OBJECT_INHERIT_ACE      0x01
0089 #define CONTAINER_INHERIT_ACE       0x02
0090 #define NO_PROPAGATE_INHERIT_ACE    0x04
0091 #define INHERIT_ONLY_ACE        0x08
0092 #define INHERITED_ACE           0x10
0093 #define SUCCESSFUL_ACCESS_ACE_FLAG  0x40
0094 #define FAILED_ACCESS_ACE_FLAG      0x80
0095
0096 /*
0097  * Maximum size of a string representation of a SID:
0098  *
0099  * The fields are unsigned values in decimal. So:
0100  *
0101  * u8:  max 3 bytes in decimal
0102  * u32: max 10 bytes in decimal
0103  *
0104  * "S-" + 3 bytes for version field + 15 for authority field + NULL terminator
0105  *
0106  * For authority field, max is when all 6 values are non-zero and it must be
0107  * represented in hex. So "-0x" + 12 hex digits.
0108  *
0109  * Add 11 bytes for each subauthority field (10 bytes each + 1 for '-')
0110  */
0111 #define SID_STRING_BASE_SIZE (2 + 3 + 15 + 1)
0112 #define SID_STRING_SUBAUTH_SIZE (11) /* size of a single subauth string */
0113
0114 #define DOMAIN_USER_RID_LE  cpu_to_le32(513)
0115
0116 struct ksmbd_conn;
0117
0118 struct smb_ntsd {
0119     __le16 revision; /* revision level */
0120     __le16 type;
0121     __le32 osidoffset;
0122     __le32 gsidoffset;
0123     __le32 sacloffset;
0124     __le32 dacloffset;
0125 } __packed;
0126
0127 struct smb_sid {
0128     __u8 revision; /* revision level */
0129     __u8 num_subauth;
0130     __u8 authority[NUM_AUTHS];
0131     __le32 sub_auth[SID_MAX_SUB_AUTHORITIES]; /* sub_auth[num_subauth] */
0132 } __packed;
0133
0134 /* size of a struct cifs_sid, sans sub_auth array */
0135 #define CIFS_SID_BASE_SIZE (1 + 1 + NUM_AUTHS)
0136
0137 struct smb_acl {
0138     __le16 revision; /* revision level */
0139     __le16 size;
0140     __le32 num_aces;
0141 } __packed;
0142
0143 struct smb_ace {
0144     __u8 type;
0145     __u8 flags;
0146     __le16 size;
0147     __le32 access_req;
0148     struct smb_sid sid; /* ie UUID of user or group who gets these perms */
0149 } __packed;
0150
0151 struct smb_fattr {
0152     kuid_t  cf_uid;
0153     kgid_t  cf_gid;
0154     umode_t cf_mode;
0155     __le32 daccess;
0156     struct posix_acl *cf_acls;
0157     struct posix_acl *cf_dacls;
0158 };
0159
0160 struct posix_ace_state {
0161     u32 allow;
0162     u32 deny;
0163 };
0164
0165 struct posix_user_ace_state {
0166     union {
0167         kuid_t uid;
0168         kgid_t gid;
0169     };
0170     struct posix_ace_state perms;
0171 };
0172
0173 struct posix_ace_state_array {
0174     int n;
0175     struct posix_user_ace_state aces[];
0176 };
0177
0178 /*
0179  * while processing the nfsv4 ace, this maintains the partial permissions
0180  * calculated so far:
0181  */
0182
0183 struct posix_acl_state {
0184     struct posix_ace_state owner;
0185     struct posix_ace_state group;
0186     struct posix_ace_state other;
0187     struct posix_ace_state everyone;
0188     struct posix_ace_state mask; /* deny unused in this case */
0189     struct posix_ace_state_array *users;
0190     struct posix_ace_state_array *groups;
0191 };
0192
0193 int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
0194            int acl_len, struct smb_fattr *fattr);
0195 int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
0196            struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info,
0197            __u32 *secdesclen, struct smb_fattr *fattr);
0198 int init_acl_state(struct posix_acl_state *state, int cnt);
0199 void free_acl_state(struct posix_acl_state *state);
0200 void posix_state_to_acl(struct posix_acl_state *state,
0201             struct posix_acl_entry *pace);
0202 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid);
0203 bool smb_inherit_flags(int flags, bool is_dir);
0204 int smb_inherit_dacl(struct ksmbd_conn *conn, struct path *path,
0205              unsigned int uid, unsigned int gid);
0206 int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
0207             __le32 *pdaccess, int uid);
0208 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
0209          struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
0210          bool type_check);
0211 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid);
0212 void ksmbd_init_domain(u32 *sub_auth);
0213
0214 static inline uid_t posix_acl_uid_translate(struct user_namespace *mnt_userns,
0215                         struct posix_acl_entry *pace)
0216 {
0217     kuid_t kuid;
0218
0219     /* If this is an idmapped mount, apply the idmapping. */
0220     kuid = mapped_kuid_fs(mnt_userns, &init_user_ns, pace->e_uid);
0221
0222     /* Translate the kuid into a userspace id ksmbd would see. */
0223     return from_kuid(&init_user_ns, kuid);
0224 }
0225
0226 static inline gid_t posix_acl_gid_translate(struct user_namespace *mnt_userns,
0227                         struct posix_acl_entry *pace)
0228 {
0229     kgid_t kgid;
0230
0231     /* If this is an idmapped mount, apply the idmapping. */
0232     kgid = mapped_kgid_fs(mnt_userns, &init_user_ns, pace->e_gid);
0233
0234     /* Translate the kgid into a userspace id ksmbd would see. */
0235     return from_kgid(&init_user_ns, kgid);
0236 }
0237
0238 #endif /* _SMBACL_H */