// SPDX-License-Identifier: LGPL-2.1
/*
 *
 *   Copyright (c) International Business Machines  Corp., 2003, 2007
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 */

#include <linux/fs.h>
#include <linux/posix_acl_xattr.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include "cifsfs.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "cifs_ioctl.h"

#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
/*
 * Although these three are just aliases for the above, need to move away from
 * confusing users and using the 20+ year old term 'cifs' when it is no longer
 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
 */
#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
#define SMB3_XATTR_CIFS_NTSD_SACL "system.smb3_ntsd_sacl" /* SACL only */
#define SMB3_XATTR_CIFS_NTSD_OWNER "system.smb3_ntsd_owner" /* owner only */
#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
/* BB need to add server (Samba e.g) support for security and trusted prefix */

enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
        XATTR_CIFS_NTSD_SACL, XATTR_CIFS_NTSD_OWNER,
        XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };

static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
                           struct inode *inode, const char *full_path,
                           const void *value, size_t size)
{
        ssize_t rc = -EOPNOTSUPP;
        __u32 *pattrib = (__u32 *)value;
        __u32 attrib;
        FILE_BASIC_INFO info_buf;

        if ((value == NULL) || (size != sizeof(__u32)))
                return -ERANGE;

        memset(&info_buf, 0, sizeof(info_buf));
        attrib = *pattrib;
        info_buf.Attributes = cpu_to_le32(attrib);
        if (pTcon->ses->server->ops->set_file_info)
                rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
                                &info_buf, xid);
        if (rc == 0)
                CIFS_I(inode)->cifsAttrs = attrib;

        return rc;
}

static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
                                  struct inode *inode, const char *full_path,
                                  const void *value, size_t size)
{
        ssize_t rc = -EOPNOTSUPP;
        __u64 *pcreation_time = (__u64 *)value;
        __u64 creation_time;
        FILE_BASIC_INFO info_buf;

        if ((value == NULL) || (size != sizeof(__u64)))
                return -ERANGE;

        memset(&info_buf, 0, sizeof(info_buf));
        creation_time = *pcreation_time;
        info_buf.CreationTime = cpu_to_le64(creation_time);
        if (pTcon->ses->server->ops->set_file_info)
                rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
                                &info_buf, xid);
        if (rc == 0)
                CIFS_I(inode)->createtime = creation_time;

        return rc;
}

static int cifs_xattr_set(const struct xattr_handler *handler,
                          struct mnt_idmap *idmap,
                          struct dentry *dentry, struct inode *inode,
                          const char *name, const void *value,
                          size_t size, int flags)
{
        int rc = -EOPNOTSUPP;
        unsigned int xid;
        struct super_block *sb = dentry->d_sb;
        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
        void *page;

        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);
        pTcon = tlink_tcon(tlink);

        xid = get_xid();
        page = alloc_dentry_path();

        full_path = build_path_from_dentry(dentry, page);
        if (IS_ERR(full_path)) {
                rc = PTR_ERR(full_path);
                goto out;
        }
        /* return dos attributes as pseudo xattr */
        /* return alt name if available as pseudo attr */

        /* if proc/fs/cifs/streamstoxattr is set then
                search server for EAs or streams to
                returns as xattrs */
        if (size > MAX_EA_VALUE_SIZE) {
                cifs_dbg(FYI, "size of EA value too large\n");
                rc = -EOPNOTSUPP;
                goto out;
        }

        switch (handler->flags) {
        case XATTR_USER:
                cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
                if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
                    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
                        rc = cifs_attrib_set(xid, pTcon, inode, full_path,
                                        value, size);
                        if (rc == 0) /* force revalidate of the inode */
                                CIFS_I(inode)->time = 0;
                        break;
                } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
                           (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
                        rc = cifs_creation_time_set(xid, pTcon, inode,
                                        full_path, value, size);
                        if (rc == 0) /* force revalidate of the inode */
                                CIFS_I(inode)->time = 0;
                        break;
                }

                if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_NO_XATTR)
                        goto out;

                if (pTcon->ses->server->ops->set_EA) {
                        rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
                                full_path, name, value, (__u16)size,
                                cifs_sb->local_nls, cifs_sb);
                        if (rc == 0)
                                inode_set_ctime_current(inode);
                }
                break;

        case XATTR_CIFS_ACL:
        case XATTR_CIFS_NTSD_SACL:
        case XATTR_CIFS_NTSD_OWNER:
        case XATTR_CIFS_NTSD:
        case XATTR_CIFS_NTSD_FULL: {
                struct smb_ntsd *pacl;

                if (!value)
                        goto out;
                pacl = kmalloc(size, GFP_KERNEL);
                if (!pacl) {
                        rc = -ENOMEM;
                } else {
                        memcpy(pacl, value, size);
                        if (pTcon->ses->server->ops->set_acl) {
                                int aclflags = 0;

                                switch (handler->flags) {
                                case XATTR_CIFS_NTSD_FULL:
                                        aclflags = (CIFS_ACL_OWNER |
                                                    CIFS_ACL_GROUP |
                                                    CIFS_ACL_DACL |
                                                    CIFS_ACL_SACL);
                                        break;
                                case XATTR_CIFS_NTSD:
                                        aclflags = (CIFS_ACL_OWNER |
                                                    CIFS_ACL_GROUP |
                                                    CIFS_ACL_DACL);
                                        break;
                                case XATTR_CIFS_NTSD_OWNER:
                                        aclflags = (CIFS_ACL_OWNER |
                                                    CIFS_ACL_GROUP);
                                        break;
                                case XATTR_CIFS_NTSD_SACL:
                                        aclflags = CIFS_ACL_SACL;
                                        break;
                                case XATTR_CIFS_ACL:
                                default:
                                        aclflags = CIFS_ACL_DACL;
                                }

                                rc = pTcon->ses->server->ops->set_acl(pacl,
                                        size, inode, full_path, aclflags);
                        } else {
                                rc = -EOPNOTSUPP;
                        }
                        if (rc == 0) /* force revalidate of the inode */
                                CIFS_I(inode)->time = 0;
                        kfree(pacl);
                }
                break;
        }
        }

out:
        free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
}

static int cifs_attrib_get(struct dentry *dentry,
                           struct inode *inode, void *value,
                           size_t size)
{
        ssize_t rc;
        __u32 *pattribute;

        rc = cifs_revalidate_dentry_attr(dentry);

        if (rc)
                return rc;

        if ((value == NULL) || (size == 0))
                return sizeof(__u32);
        else if (size < sizeof(__u32))
                return -ERANGE;

        /* return dos attributes as pseudo xattr */
        pattribute = (__u32 *)value;
        *pattribute = CIFS_I(inode)->cifsAttrs;

        return sizeof(__u32);
}

static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
                                  void *value, size_t size)
{
        ssize_t rc;
        __u64 *pcreatetime;

        rc = cifs_revalidate_dentry_attr(dentry);
        if (rc)
                return rc;

        if ((value == NULL) || (size == 0))
                return sizeof(__u64);
        else if (size < sizeof(__u64))
                return -ERANGE;

        /* return dos attributes as pseudo xattr */
        pcreatetime = (__u64 *)value;
        *pcreatetime = CIFS_I(inode)->createtime;
        return sizeof(__u64);
}


static int cifs_xattr_get(const struct xattr_handler *handler,
                          struct dentry *dentry, struct inode *inode,
                          const char *name, void *value, size_t size)
{
        ssize_t rc = -EOPNOTSUPP;
        unsigned int xid;
        struct super_block *sb = dentry->d_sb;
        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
        void *page;

        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);
        pTcon = tlink_tcon(tlink);

        xid = get_xid();
        page = alloc_dentry_path();

        full_path = build_path_from_dentry(dentry, page);
        if (IS_ERR(full_path)) {
                rc = PTR_ERR(full_path);
                goto out;
        }

        /* return alt name if available as pseudo attr */
        switch (handler->flags) {
        case XATTR_USER:
                cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
                if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
                    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
                        rc = cifs_attrib_get(dentry, inode, value, size);
                        break;
                } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
                    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
                        rc = cifs_creation_time_get(dentry, inode, value, size);
                        break;
                }

                if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_NO_XATTR)
                        goto out;

                if (pTcon->ses->server->ops->query_all_EAs)
                        rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
                                full_path, name, value, size, cifs_sb);
                break;

        case XATTR_CIFS_ACL:
        case XATTR_CIFS_NTSD_SACL:
        case XATTR_CIFS_NTSD_OWNER:
        case XATTR_CIFS_NTSD:
        case XATTR_CIFS_NTSD_FULL: {
                /*
                 * fetch owner, DACL, and SACL if asked for full descriptor,
                 * fetch owner and DACL otherwise
                 */
                u32 acllen, extra_info;
                struct smb_ntsd *pacl;

                if (pTcon->ses->server->ops->get_acl == NULL)
                        goto out; /* rc already EOPNOTSUPP */

                switch (handler->flags) {
                case XATTR_CIFS_NTSD_FULL:
                        extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO | SACL_SECINFO;
                        break;
                case XATTR_CIFS_NTSD:
                        extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
                        break;
                case XATTR_CIFS_NTSD_OWNER:
                        extra_info = OWNER_SECINFO | GROUP_SECINFO;
                        break;
                case XATTR_CIFS_NTSD_SACL:
                        extra_info = SACL_SECINFO;
                        break;
                case XATTR_CIFS_ACL:
                default:
                        extra_info = DACL_SECINFO;
                        break;
                }
                pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
                                inode, full_path, &acllen, extra_info);
                if (IS_ERR(pacl)) {
                        rc = PTR_ERR(pacl);
                        cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
                                 __func__, rc);
                } else {
                        if (value) {
                                if (acllen > size)
                                        acllen = -ERANGE;
                                else
                                        memcpy(value, pacl, acllen);
                        }
                        rc = acllen;
                        kfree(pacl);
                }
                break;
        }
        }

        /* We could add an additional check for streams ie
            if proc/fs/cifs/streamstoxattr is set then
                search server for EAs or streams to
                returns as xattrs */

        if (rc == -EINVAL)
                rc = -EOPNOTSUPP;

out:
        free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
}

ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
{
        ssize_t rc = -EOPNOTSUPP;
        unsigned int xid;
        struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
        void *page;

        if (unlikely(cifs_forced_shutdown(cifs_sb)))
                return smb_EIO(smb_eio_trace_forced_shutdown);

        if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_NO_XATTR)
                return -EOPNOTSUPP;

        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);
        pTcon = tlink_tcon(tlink);

        xid = get_xid();
        page = alloc_dentry_path();

        full_path = build_path_from_dentry(direntry, page);
        if (IS_ERR(full_path)) {
                rc = PTR_ERR(full_path);
                goto list_ea_exit;
        }
        /* return dos attributes as pseudo xattr */
        /* return alt name if available as pseudo attr */

        /* if proc/fs/cifs/streamstoxattr is set then
                search server for EAs or streams to
                returns as xattrs */

        if (pTcon->ses->server->ops->query_all_EAs)
                rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
                                full_path, NULL, data, buf_size, cifs_sb);
list_ea_exit:
        free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
}

static const struct xattr_handler cifs_user_xattr_handler = {
        .prefix = XATTR_USER_PREFIX,
        .flags = XATTR_USER,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

/* os2.* attributes are treated like user.* attributes */
static const struct xattr_handler cifs_os2_xattr_handler = {
        .prefix = XATTR_OS2_PREFIX,
        .flags = XATTR_USER,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
        .name = CIFS_XATTR_CIFS_ACL,
        .flags = XATTR_CIFS_ACL,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_acl_xattr_handler = {
        .name = SMB3_XATTR_CIFS_ACL,
        .flags = XATTR_CIFS_ACL,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

static const struct xattr_handler smb3_ntsd_sacl_xattr_handler = {
        .name = SMB3_XATTR_CIFS_NTSD_SACL,
        .flags = XATTR_CIFS_NTSD_SACL,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

static const struct xattr_handler smb3_ntsd_owner_xattr_handler = {
        .name = SMB3_XATTR_CIFS_NTSD_OWNER,
        .flags = XATTR_CIFS_NTSD_OWNER,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
        .name = CIFS_XATTR_CIFS_NTSD,
        .flags = XATTR_CIFS_NTSD,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_ntsd_xattr_handler = {
        .name = SMB3_XATTR_CIFS_NTSD,
        .flags = XATTR_CIFS_NTSD,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
        .name = CIFS_XATTR_CIFS_NTSD_FULL,
        .flags = XATTR_CIFS_NTSD_FULL,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

/*
 * Although this is just an alias for the above, need to move away from
 * confusing users and using the 20 year old term 'cifs' when it is no
 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
 * SMB3 and later are highly secure.
 */
static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
        .name = SMB3_XATTR_CIFS_NTSD_FULL,
        .flags = XATTR_CIFS_NTSD_FULL,
        .get = cifs_xattr_get,
        .set = cifs_xattr_set,
};

const struct xattr_handler * const cifs_xattr_handlers[] = {
        &cifs_user_xattr_handler,
        &cifs_os2_xattr_handler,
        &cifs_cifs_acl_xattr_handler,
        &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
        &smb3_ntsd_sacl_xattr_handler,
        &smb3_ntsd_owner_xattr_handler,
        &cifs_cifs_ntsd_xattr_handler,
        &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
        &cifs_cifs_ntsd_full_xattr_handler,
        &smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
        NULL
};