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