fs/ksmbd/smbacl.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /*
   3  *   Copyright (c) International Business Machines  Corp., 2007
   4  *   Author(s): Steve French (sfrench@us.ibm.com)
   5  *   Modified by Namjae Jeon (linkinjeon@kernel.org)
   6  */
   7
   8 #ifndef _SMBACL_H
   9 #define _SMBACL_H
  10
  11 #include <linux/fs.h>
  12 #include <linux/namei.h>
  13 #include <linux/posix_acl.h>
  14
  15 #include "mgmt/tree_connect.h"
  16
  17 #define NUM_AUTHS (6)   /* number of authority fields */
  18 #define SID_MAX_SUB_AUTHORITIES (15) /* max number of sub authority fields */
  19
  20 /*
  21  * ACE types - see MS-DTYP 2.4.4.1
  22  */
  23 enum {
  24         ACCESS_ALLOWED,
  25         ACCESS_DENIED,
  26 };
  27
  28 /*
  29  * Security ID types
  30  */
  31 enum {
  32         SIDOWNER = 1,
  33         SIDGROUP,
  34         SIDCREATOR_OWNER,
  35         SIDCREATOR_GROUP,
  36         SIDUNIX_USER,
  37         SIDUNIX_GROUP,
  38         SIDNFS_USER,
  39         SIDNFS_GROUP,
  40         SIDNFS_MODE,
  41 };
  42
  43 /* Revision for ACLs */
  44 #define SD_REVISION     1
  45
  46 /* Control flags for Security Descriptor */
  47 #define OWNER_DEFAULTED         0x0001
  48 #define GROUP_DEFAULTED         0x0002
  49 #define DACL_PRESENT            0x0004
  50 #define DACL_DEFAULTED          0x0008
  51 #define SACL_PRESENT            0x0010
  52 #define SACL_DEFAULTED          0x0020
  53 #define DACL_TRUSTED            0x0040
  54 #define SERVER_SECURITY         0x0080
  55 #define DACL_AUTO_INHERIT_REQ   0x0100
  56 #define SACL_AUTO_INHERIT_REQ   0x0200
  57 #define DACL_AUTO_INHERITED     0x0400
  58 #define SACL_AUTO_INHERITED     0x0800
  59 #define DACL_PROTECTED          0x1000
  60 #define SACL_PROTECTED          0x2000
  61 #define RM_CONTROL_VALID        0x4000
  62 #define SELF_RELATIVE           0x8000
  63
  64 /* ACE types - see MS-DTYP 2.4.4.1 */
  65 #define ACCESS_ALLOWED_ACE_TYPE 0x00
  66 #define ACCESS_DENIED_ACE_TYPE  0x01
  67 #define SYSTEM_AUDIT_ACE_TYPE   0x02
  68 #define SYSTEM_ALARM_ACE_TYPE   0x03
  69 #define ACCESS_ALLOWED_COMPOUND_ACE_TYPE 0x04
  70 #define ACCESS_ALLOWED_OBJECT_ACE_TYPE  0x05
  71 #define ACCESS_DENIED_OBJECT_ACE_TYPE   0x06
  72 #define SYSTEM_AUDIT_OBJECT_ACE_TYPE    0x07
  73 #define SYSTEM_ALARM_OBJECT_ACE_TYPE    0x08
  74 #define ACCESS_ALLOWED_CALLBACK_ACE_TYPE 0x09
  75 #define ACCESS_DENIED_CALLBACK_ACE_TYPE 0x0A
  76 #define ACCESS_ALLOWED_CALLBACK_OBJECT_ACE_TYPE 0x0B
  77 #define ACCESS_DENIED_CALLBACK_OBJECT_ACE_TYPE  0x0C
  78 #define SYSTEM_AUDIT_CALLBACK_ACE_TYPE  0x0D
  79 #define SYSTEM_ALARM_CALLBACK_ACE_TYPE  0x0E /* Reserved */
  80 #define SYSTEM_AUDIT_CALLBACK_OBJECT_ACE_TYPE 0x0F
  81 #define SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE 0x10 /* reserved */
  82 #define SYSTEM_MANDATORY_LABEL_ACE_TYPE 0x11
  83 #define SYSTEM_RESOURCE_ATTRIBUTE_ACE_TYPE 0x12
  84 #define SYSTEM_SCOPED_POLICY_ID_ACE_TYPE 0x13
  85
  86 /* ACE flags */
  87 #define OBJECT_INHERIT_ACE              0x01
  88 #define CONTAINER_INHERIT_ACE           0x02
  89 #define NO_PROPAGATE_INHERIT_ACE        0x04
  90 #define INHERIT_ONLY_ACE                0x08
  91 #define INHERITED_ACE                   0x10
  92 #define SUCCESSFUL_ACCESS_ACE_FLAG      0x40
  93 #define FAILED_ACCESS_ACE_FLAG          0x80
  94
  95 /*
  96  * Maximum size of a string representation of a SID:
  97  *
  98  * The fields are unsigned values in decimal. So:
  99  *
 100  * u8:  max 3 bytes in decimal
 101  * u32: max 10 bytes in decimal
 102  *
 103  * "S-" + 3 bytes for version field + 15 for authority field + NULL terminator
 104  *
 105  * For authority field, max is when all 6 values are non-zero and it must be
 106  * represented in hex. So "-0x" + 12 hex digits.
 107  *
 108  * Add 11 bytes for each subauthority field (10 bytes each + 1 for '-')
 109  */
 110 #define SID_STRING_BASE_SIZE (2 + 3 + 15 + 1)
 111 #define SID_STRING_SUBAUTH_SIZE (11) /* size of a single subauth string */
 112
 113 #define DOMAIN_USER_RID_LE      cpu_to_le32(513)
 114
 115 struct ksmbd_conn;
 116
 117 struct smb_ntsd {
 118         __le16 revision; /* revision level */
 119         __le16 type;
 120         __le32 osidoffset;
 121         __le32 gsidoffset;
 122         __le32 sacloffset;
 123         __le32 dacloffset;
 124 } __packed;
 125
 126 struct smb_sid {
 127         __u8 revision; /* revision level */
 128         __u8 num_subauth;
 129         __u8 authority[NUM_AUTHS];
 130         __le32 sub_auth[SID_MAX_SUB_AUTHORITIES]; /* sub_auth[num_subauth] */
 131 } __packed;
 132
 133 /* size of a struct cifs_sid, sans sub_auth array */
 134 #define CIFS_SID_BASE_SIZE (1 + 1 + NUM_AUTHS)
 135
 136 struct smb_acl {
 137         __le16 revision; /* revision level */
 138         __le16 size;
 139         __le32 num_aces;
 140 } __packed;
 141
 142 struct smb_ace {
 143         __u8 type;
 144         __u8 flags;
 145         __le16 size;
 146         __le32 access_req;
 147         struct smb_sid sid; /* ie UUID of user or group who gets these perms */
 148 } __packed;
 149
 150 struct smb_fattr {
 151         kuid_t  cf_uid;
 152         kgid_t  cf_gid;
 153         umode_t cf_mode;
 154         __le32 daccess;
 155         struct posix_acl *cf_acls;
 156         struct posix_acl *cf_dacls;
 157 };
 158
 159 struct posix_ace_state {
 160         u32 allow;
 161         u32 deny;
 162 };
 163
 164 struct posix_user_ace_state {
 165         union {
 166                 kuid_t uid;
 167                 kgid_t gid;
 168         };
 169         struct posix_ace_state perms;
 170 };
 171
 172 struct posix_ace_state_array {
 173         int n;
 174         struct posix_user_ace_state aces[];
 175 };
 176
 177 /*
 178  * while processing the nfsv4 ace, this maintains the partial permissions
 179  * calculated so far:
 180  */
 181
 182 struct posix_acl_state {
 183         struct posix_ace_state owner;
 184         struct posix_ace_state group;
 185         struct posix_ace_state other;
 186         struct posix_ace_state everyone;
 187         struct posix_ace_state mask; /* deny unused in this case */
 188         struct posix_ace_state_array *users;
 189         struct posix_ace_state_array *groups;
 190 };
 191
 192 int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 193                    int acl_len, struct smb_fattr *fattr);
 194 int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 195                    struct smb_ntsd *ppntsd, int addition_info,
 196                    __u32 *secdesclen, struct smb_fattr *fattr);
 197 int init_acl_state(struct posix_acl_state *state, int cnt);
 198 void free_acl_state(struct posix_acl_state *state);
 199 void posix_state_to_acl(struct posix_acl_state *state,
 200                         struct posix_acl_entry *pace);
 201 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid);
 202 bool smb_inherit_flags(int flags, bool is_dir);
 203 int smb_inherit_dacl(struct ksmbd_conn *conn, struct path *path,
 204                      unsigned int uid, unsigned int gid);
 205 int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
 206                         __le32 *pdaccess, int uid);
 207 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 208                  struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
 209                  bool type_check);
 210 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid);
 211 void ksmbd_init_domain(u32 *sub_auth);
 212
 213 static inline uid_t posix_acl_uid_translate(struct user_namespace *mnt_userns,
 214                                             struct posix_acl_entry *pace)
 215 {
 216         kuid_t kuid;
 217
 218         /* If this is an idmapped mount, apply the idmapping. */
 219         kuid = kuid_into_mnt(mnt_userns, pace->e_uid);
 220
 221         /* Translate the kuid into a userspace id ksmbd would see. */
 222         return from_kuid(&init_user_ns, kuid);
 223 }
 224
 225 static inline gid_t posix_acl_gid_translate(struct user_namespace *mnt_userns,
 226                                             struct posix_acl_entry *pace)
 227 {
 228         kgid_t kgid;
 229
 230         /* If this is an idmapped mount, apply the idmapping. */
 231         kgid = kgid_into_mnt(mnt_userns, pace->e_gid);
 232
 233         /* Translate the kgid into a userspace id ksmbd would see. */
 234         return from_kgid(&init_user_ns, kgid);
 235 }
 236
 237 #endif /* _SMBACL_H */