LXR linux/fs/cifs/xattr.c

   1// SPDX-License-Identifier: LGPL-2.1
   2/*
   3 *
   4 *   Copyright (c) International Business Machines  Corp., 2003, 2007
   5 *   Author(s): Steve French (sfrench@us.ibm.com)
   6 *
   7 */
   8
   9#include <linux/fs.h>
  10#include <linux/posix_acl_xattr.h>
  11#include <linux/slab.h>
  12#include <linux/xattr.h>
  13#include "cifsfs.h"
  14#include "cifspdu.h"
  15#include "cifsglob.h"
  16#include "cifsproto.h"
  17#include "cifs_debug.h"
  18#include "cifs_fs_sb.h"
  19#include "cifs_unicode.h"
  20#include "cifs_ioctl.h"
  21
  22#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
  23#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
  24#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
  25#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
  26#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
  27#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
  28/*
  29 * Although these three are just aliases for the above, need to move away from
  30 * confusing users and using the 20+ year old term 'cifs' when it is no longer
  31 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
  32 */
  33#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
  34#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
  35#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
  36#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
  37#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
  38/* BB need to add server (Samba e.g) support for security and trusted prefix */
  39
  40enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
  41        XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
  42
  43static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
  44                           struct inode *inode, const char *full_path,
  45                           const void *value, size_t size)
  46{
  47        ssize_t rc = -EOPNOTSUPP;
  48        __u32 *pattrib = (__u32 *)value;
  49        __u32 attrib;
  50        FILE_BASIC_INFO info_buf;
  51
  52        if ((value == NULL) || (size != sizeof(__u32)))
  53                return -ERANGE;
  54
  55        memset(&info_buf, 0, sizeof(info_buf));
  56        attrib = *pattrib;
  57        info_buf.Attributes = cpu_to_le32(attrib);
  58        if (pTcon->ses->server->ops->set_file_info)
  59                rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  60                                &info_buf, xid);
  61        if (rc == 0)
  62                CIFS_I(inode)->cifsAttrs = attrib;
  63
  64        return rc;
  65}
  66
  67static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
  68                                  struct inode *inode, const char *full_path,
  69                                  const void *value, size_t size)
  70{
  71        ssize_t rc = -EOPNOTSUPP;
  72        __u64 *pcreation_time = (__u64 *)value;
  73        __u64 creation_time;
  74        FILE_BASIC_INFO info_buf;
  75
  76        if ((value == NULL) || (size != sizeof(__u64)))
  77                return -ERANGE;
  78
  79        memset(&info_buf, 0, sizeof(info_buf));
  80        creation_time = *pcreation_time;
  81        info_buf.CreationTime = cpu_to_le64(creation_time);
  82        if (pTcon->ses->server->ops->set_file_info)
  83                rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
  84                                &info_buf, xid);
  85        if (rc == 0)
  86                CIFS_I(inode)->createtime = creation_time;
  87
  88        return rc;
  89}
  90
  91static int cifs_xattr_set(const struct xattr_handler *handler,
  92                          struct user_namespace *mnt_userns,
  93                          struct dentry *dentry, struct inode *inode,
  94                          const char *name, const void *value,
  95                          size_t size, int flags)
  96{
  97        int rc = -EOPNOTSUPP;
  98        unsigned int xid;
  99        struct super_block *sb = dentry->d_sb;
 100        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 101        struct tcon_link *tlink;
 102        struct cifs_tcon *pTcon;
 103        const char *full_path;
 104        void *page;
 105
 106        tlink = cifs_sb_tlink(cifs_sb);
 107        if (IS_ERR(tlink))
 108                return PTR_ERR(tlink);
 109        pTcon = tlink_tcon(tlink);
 110
 111        xid = get_xid();
 112        page = alloc_dentry_path();
 113
 114        full_path = build_path_from_dentry(dentry, page);
 115        if (IS_ERR(full_path)) {
 116                rc = PTR_ERR(full_path);
 117                goto out;
 118        }
 119        /* return dos attributes as pseudo xattr */
 120        /* return alt name if available as pseudo attr */
 121
 122        /* if proc/fs/cifs/streamstoxattr is set then
 123                search server for EAs or streams to
 124                returns as xattrs */
 125        if (size > MAX_EA_VALUE_SIZE) {
 126                cifs_dbg(FYI, "size of EA value too large\n");
 127                rc = -EOPNOTSUPP;
 128                goto out;
 129        }
 130
 131        switch (handler->flags) {
 132        case XATTR_USER:
 133                cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
 134                if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 135                    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 136                        rc = cifs_attrib_set(xid, pTcon, inode, full_path,
 137                                        value, size);
 138                        if (rc == 0) /* force revalidate of the inode */
 139                                CIFS_I(inode)->time = 0;
 140                        break;
 141                } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 142                           (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 143                        rc = cifs_creation_time_set(xid, pTcon, inode,
 144                                        full_path, value, size);
 145                        if (rc == 0) /* force revalidate of the inode */
 146                                CIFS_I(inode)->time = 0;
 147                        break;
 148                }
 149
 150                if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 151                        goto out;
 152
 153                if (pTcon->ses->server->ops->set_EA)
 154                        rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
 155                                full_path, name, value, (__u16)size,
 156                                cifs_sb->local_nls, cifs_sb);
 157                break;
 158
 159        case XATTR_CIFS_ACL:
 160        case XATTR_CIFS_NTSD:
 161        case XATTR_CIFS_NTSD_FULL: {
 162                struct cifs_ntsd *pacl;
 163
 164                if (!value)
 165                        goto out;
 166                pacl = kmalloc(size, GFP_KERNEL);
 167                if (!pacl) {
 168                        rc = -ENOMEM;
 169                } else {
 170                        memcpy(pacl, value, size);
 171                        if (pTcon->ses->server->ops->set_acl) {
 172                                int aclflags = 0;
 173                                rc = 0;
 174
 175                                switch (handler->flags) {
 176                                case XATTR_CIFS_NTSD_FULL:
 177                                        aclflags = (CIFS_ACL_OWNER |
 178                                                    CIFS_ACL_DACL |
 179                                                    CIFS_ACL_SACL);
 180                                        break;
 181                                case XATTR_CIFS_NTSD:
 182                                        aclflags = (CIFS_ACL_OWNER |
 183                                                    CIFS_ACL_DACL);
 184                                        break;
 185                                case XATTR_CIFS_ACL:
 186                                default:
 187                                        aclflags = CIFS_ACL_DACL;
 188                                }
 189
 190                                rc = pTcon->ses->server->ops->set_acl(pacl,
 191                                        size, inode, full_path, aclflags);
 192                        } else {
 193                                rc = -EOPNOTSUPP;
 194                        }
 195                        if (rc == 0) /* force revalidate of the inode */
 196                                CIFS_I(inode)->time = 0;
 197                        kfree(pacl);
 198                }
 199                break;
 200        }
 201
 202        case XATTR_ACL_ACCESS:
 203#ifdef CONFIG_CIFS_POSIX
 204                if (!value)
 205                        goto out;
 206                if (sb->s_flags & SB_POSIXACL)
 207                        rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 208                                value, (const int)size,
 209                                ACL_TYPE_ACCESS, cifs_sb->local_nls,
 210                                cifs_remap(cifs_sb));
 211#endif  /* CONFIG_CIFS_POSIX */
 212                break;
 213
 214        case XATTR_ACL_DEFAULT:
 215#ifdef CONFIG_CIFS_POSIX
 216                if (!value)
 217                        goto out;
 218                if (sb->s_flags & SB_POSIXACL)
 219                        rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
 220                                value, (const int)size,
 221                                ACL_TYPE_DEFAULT, cifs_sb->local_nls,
 222                                cifs_remap(cifs_sb));
 223#endif  /* CONFIG_CIFS_POSIX */
 224                break;
 225        }
 226
 227out:
 228        free_dentry_path(page);
 229        free_xid(xid);
 230        cifs_put_tlink(tlink);
 231        return rc;
 232}
 233
 234static int cifs_attrib_get(struct dentry *dentry,
 235                           struct inode *inode, void *value,
 236                           size_t size)
 237{
 238        ssize_t rc;
 239        __u32 *pattribute;
 240
 241        rc = cifs_revalidate_dentry_attr(dentry);
 242
 243        if (rc)
 244                return rc;
 245
 246        if ((value == NULL) || (size == 0))
 247                return sizeof(__u32);
 248        else if (size < sizeof(__u32))
 249                return -ERANGE;
 250
 251        /* return dos attributes as pseudo xattr */
 252        pattribute = (__u32 *)value;
 253        *pattribute = CIFS_I(inode)->cifsAttrs;
 254
 255        return sizeof(__u32);
 256}
 257
 258static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
 259                                  void *value, size_t size)
 260{
 261        ssize_t rc;
 262        __u64 *pcreatetime;
 263
 264        rc = cifs_revalidate_dentry_attr(dentry);
 265        if (rc)
 266                return rc;
 267
 268        if ((value == NULL) || (size == 0))
 269                return sizeof(__u64);
 270        else if (size < sizeof(__u64))
 271                return -ERANGE;
 272
 273        /* return dos attributes as pseudo xattr */
 274        pcreatetime = (__u64 *)value;
 275        *pcreatetime = CIFS_I(inode)->createtime;
 276        return sizeof(__u64);
 277}
 278
 279
 280static int cifs_xattr_get(const struct xattr_handler *handler,
 281                          struct dentry *dentry, struct inode *inode,
 282                          const char *name, void *value, size_t size)
 283{
 284        ssize_t rc = -EOPNOTSUPP;
 285        unsigned int xid;
 286        struct super_block *sb = dentry->d_sb;
 287        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 288        struct tcon_link *tlink;
 289        struct cifs_tcon *pTcon;
 290        const char *full_path;
 291        void *page;
 292
 293        tlink = cifs_sb_tlink(cifs_sb);
 294        if (IS_ERR(tlink))
 295                return PTR_ERR(tlink);
 296        pTcon = tlink_tcon(tlink);
 297
 298        xid = get_xid();
 299        page = alloc_dentry_path();
 300
 301        full_path = build_path_from_dentry(dentry, page);
 302        if (IS_ERR(full_path)) {
 303                rc = PTR_ERR(full_path);
 304                goto out;
 305        }
 306
 307        /* return alt name if available as pseudo attr */
 308        switch (handler->flags) {
 309        case XATTR_USER:
 310                cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
 311                if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
 312                    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
 313                        rc = cifs_attrib_get(dentry, inode, value, size);
 314                        break;
 315                } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
 316                    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
 317                        rc = cifs_creation_time_get(dentry, inode, value, size);
 318                        break;
 319                }
 320
 321                if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 322                        goto out;
 323
 324                if (pTcon->ses->server->ops->query_all_EAs)
 325                        rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 326                                full_path, name, value, size, cifs_sb);
 327                break;
 328
 329        case XATTR_CIFS_ACL:
 330        case XATTR_CIFS_NTSD:
 331        case XATTR_CIFS_NTSD_FULL: {
 332                /*
 333                 * fetch owner, DACL, and SACL if asked for full descriptor,
 334                 * fetch owner and DACL otherwise
 335                 */
 336                u32 acllen, extra_info;
 337                struct cifs_ntsd *pacl;
 338
 339                if (pTcon->ses->server->ops->get_acl == NULL)
 340                        goto out; /* rc already EOPNOTSUPP */
 341
 342                if (handler->flags == XATTR_CIFS_NTSD_FULL) {
 343                        extra_info = SACL_SECINFO;
 344                } else {
 345                        extra_info = 0;
 346                }
 347                pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 348                                inode, full_path, &acllen, extra_info);
 349                if (IS_ERR(pacl)) {
 350                        rc = PTR_ERR(pacl);
 351                        cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
 352                                 __func__, rc);
 353                } else {
 354                        if (value) {
 355                                if (acllen > size)
 356                                        acllen = -ERANGE;
 357                                else
 358                                        memcpy(value, pacl, acllen);
 359                        }
 360                        rc = acllen;
 361                        kfree(pacl);
 362                }
 363                break;
 364        }
 365
 366        case XATTR_ACL_ACCESS:
 367#ifdef CONFIG_CIFS_POSIX
 368                if (sb->s_flags & SB_POSIXACL)
 369                        rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 370                                value, size, ACL_TYPE_ACCESS,
 371                                cifs_sb->local_nls,
 372                                cifs_remap(cifs_sb));
 373#endif  /* CONFIG_CIFS_POSIX */
 374                break;
 375
 376        case XATTR_ACL_DEFAULT:
 377#ifdef CONFIG_CIFS_POSIX
 378                if (sb->s_flags & SB_POSIXACL)
 379                        rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
 380                                value, size, ACL_TYPE_DEFAULT,
 381                                cifs_sb->local_nls,
 382                                cifs_remap(cifs_sb));
 383#endif  /* CONFIG_CIFS_POSIX */
 384                break;
 385        }
 386
 387        /* We could add an additional check for streams ie
 388            if proc/fs/cifs/streamstoxattr is set then
 389                search server for EAs or streams to
 390                returns as xattrs */
 391
 392        if (rc == -EINVAL)
 393                rc = -EOPNOTSUPP;
 394
 395out:
 396        free_dentry_path(page);
 397        free_xid(xid);
 398        cifs_put_tlink(tlink);
 399        return rc;
 400}
 401
 402ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
 403{
 404        ssize_t rc = -EOPNOTSUPP;
 405        unsigned int xid;
 406        struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 407        struct tcon_link *tlink;
 408        struct cifs_tcon *pTcon;
 409        const char *full_path;
 410        void *page;
 411
 412        if (unlikely(cifs_forced_shutdown(cifs_sb)))
 413                return -EIO;
 414
 415        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 416                return -EOPNOTSUPP;
 417
 418        tlink = cifs_sb_tlink(cifs_sb);
 419        if (IS_ERR(tlink))
 420                return PTR_ERR(tlink);
 421        pTcon = tlink_tcon(tlink);
 422
 423        xid = get_xid();
 424        page = alloc_dentry_path();
 425
 426        full_path = build_path_from_dentry(direntry, page);
 427        if (IS_ERR(full_path)) {
 428                rc = PTR_ERR(full_path);
 429                goto list_ea_exit;
 430        }
 431        /* return dos attributes as pseudo xattr */
 432        /* return alt name if available as pseudo attr */
 433
 434        /* if proc/fs/cifs/streamstoxattr is set then
 435                search server for EAs or streams to
 436                returns as xattrs */
 437
 438        if (pTcon->ses->server->ops->query_all_EAs)
 439                rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
 440                                full_path, NULL, data, buf_size, cifs_sb);
 441list_ea_exit:
 442        free_dentry_path(page);
 443        free_xid(xid);
 444        cifs_put_tlink(tlink);
 445        return rc;
 446}
 447
 448static const struct xattr_handler cifs_user_xattr_handler = {
 449        .prefix = XATTR_USER_PREFIX,
 450        .flags = XATTR_USER,
 451        .get = cifs_xattr_get,
 452        .set = cifs_xattr_set,
 453};
 454
 455/* os2.* attributes are treated like user.* attributes */
 456static const struct xattr_handler cifs_os2_xattr_handler = {
 457        .prefix = XATTR_OS2_PREFIX,
 458        .flags = XATTR_USER,
 459        .get = cifs_xattr_get,
 460        .set = cifs_xattr_set,
 461};
 462
 463static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
 464        .name = CIFS_XATTR_CIFS_ACL,
 465        .flags = XATTR_CIFS_ACL,
 466        .get = cifs_xattr_get,
 467        .set = cifs_xattr_set,
 468};
 469
 470/*
 471 * Although this is just an alias for the above, need to move away from
 472 * confusing users and using the 20 year old term 'cifs' when it is no
 473 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 474 * SMB3 and later are highly secure.
 475 */
 476static const struct xattr_handler smb3_acl_xattr_handler = {
 477        .name = SMB3_XATTR_CIFS_ACL,
 478        .flags = XATTR_CIFS_ACL,
 479        .get = cifs_xattr_get,
 480        .set = cifs_xattr_set,
 481};
 482
 483static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
 484        .name = CIFS_XATTR_CIFS_NTSD,
 485        .flags = XATTR_CIFS_NTSD,
 486        .get = cifs_xattr_get,
 487        .set = cifs_xattr_set,
 488};
 489
 490/*
 491 * Although this is just an alias for the above, need to move away from
 492 * confusing users and using the 20 year old term 'cifs' when it is no
 493 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 494 * SMB3 and later are highly secure.
 495 */
 496static const struct xattr_handler smb3_ntsd_xattr_handler = {
 497        .name = SMB3_XATTR_CIFS_NTSD,
 498        .flags = XATTR_CIFS_NTSD,
 499        .get = cifs_xattr_get,
 500        .set = cifs_xattr_set,
 501};
 502
 503static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
 504        .name = CIFS_XATTR_CIFS_NTSD_FULL,
 505        .flags = XATTR_CIFS_NTSD_FULL,
 506        .get = cifs_xattr_get,
 507        .set = cifs_xattr_set,
 508};
 509
 510/*
 511 * Although this is just an alias for the above, need to move away from
 512 * confusing users and using the 20 year old term 'cifs' when it is no
 513 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 514 * SMB3 and later are highly secure.
 515 */
 516static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
 517        .name = SMB3_XATTR_CIFS_NTSD_FULL,
 518        .flags = XATTR_CIFS_NTSD_FULL,
 519        .get = cifs_xattr_get,
 520        .set = cifs_xattr_set,
 521};
 522
 523
 524static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
 525        .name = XATTR_NAME_POSIX_ACL_ACCESS,
 526        .flags = XATTR_ACL_ACCESS,
 527        .get = cifs_xattr_get,
 528        .set = cifs_xattr_set,
 529};
 530
 531static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
 532        .name = XATTR_NAME_POSIX_ACL_DEFAULT,
 533        .flags = XATTR_ACL_DEFAULT,
 534        .get = cifs_xattr_get,
 535        .set = cifs_xattr_set,
 536};
 537
 538const struct xattr_handler *cifs_xattr_handlers[] = {
 539        &cifs_user_xattr_handler,
 540        &cifs_os2_xattr_handler,
 541        &cifs_cifs_acl_xattr_handler,
 542        &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 543        &cifs_cifs_ntsd_xattr_handler,
 544        &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 545        &cifs_cifs_ntsd_full_xattr_handler,
 546        &smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
 547        &cifs_posix_acl_access_xattr_handler,
 548        &cifs_posix_acl_default_xattr_handler,
 549        NULL
 550};
 551