From: xiubli@redhat.com
To: idryomov@gmail.com, ceph-devel@vger.kernel.org
Cc: jlayton@kernel.org, lhenriques@suse.de, vshankar@redhat.com,
mchangir@redhat.com, Xiubo Li <xiubli@redhat.com>
Subject: [PATCH v16 63/68] ceph: add support for handling encrypted snapshot names
Date: Mon, 27 Feb 2023 11:28:08 +0800 [thread overview]
Message-ID: <20230227032813.337906-64-xiubli@redhat.com> (raw)
In-Reply-To: <20230227032813.337906-1-xiubli@redhat.com>
From: Luís Henriques <lhenriques@suse.de>
When creating a snapshot, the .snap directories for every subdirectory will
show the snapshot name in the "long format":
# mkdir .snap/my-snap
# ls my-dir/.snap/
_my-snap_1099511627782
Encrypted snapshots will need to be able to handle these snapshot names by
encrypting/decrypting only the snapshot part of the string ('my-snap').
Also, since the MDS prevents snapshot names to be bigger than 240 characters
it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate this extra
limitation.
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/crypto.c | 192 ++++++++++++++++++++++++++++++++++++++++-------
fs/ceph/crypto.h | 4 +-
2 files changed, 166 insertions(+), 30 deletions(-)
diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
index 35e292045e9d..5bdd779217d8 100644
--- a/fs/ceph/crypto.c
+++ b/fs/ceph/crypto.c
@@ -189,16 +189,100 @@ void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_se
swap(req->r_fscrypt_auth, as->fscrypt_auth);
}
-int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, char *buf)
+/*
+ * User-created snapshots can't start with '_'. Snapshots that start with this
+ * character are special (hint: there aren't real snapshots) and use the
+ * following format:
+ *
+ * _<SNAPSHOT-NAME>_<INODE-NUMBER>
+ *
+ * where:
+ * - <SNAPSHOT-NAME> - the real snapshot name that may need to be decrypted,
+ * - <INODE-NUMBER> - the inode number (in decimal) for the actual snapshot
+ *
+ * This function parses these snapshot names and returns the inode
+ * <INODE-NUMBER>. 'name_len' will also bet set with the <SNAPSHOT-NAME>
+ * length.
+ */
+static struct inode *parse_longname(const struct inode *parent, const char *name,
+ int *name_len)
+{
+ struct inode *dir = NULL;
+ struct ceph_vino vino = { .snap = CEPH_NOSNAP };
+ char *inode_number;
+ char *name_end;
+ int orig_len = *name_len;
+ int ret = -EIO;
+
+ /* Skip initial '_' */
+ name++;
+ name_end = strrchr(name, '_');
+ if (!name_end) {
+ dout("Failed to parse long snapshot name: %s\n", name);
+ return ERR_PTR(-EIO);
+ }
+ *name_len = (name_end - name);
+ if (*name_len <= 0) {
+ pr_err("Failed to parse long snapshot name\n");
+ return ERR_PTR(-EIO);
+ }
+
+ /* Get the inode number */
+ inode_number = kmemdup_nul(name_end + 1,
+ orig_len - *name_len - 2,
+ GFP_KERNEL);
+ if (!inode_number)
+ return ERR_PTR(-ENOMEM);
+ ret = kstrtou64(inode_number, 10, &vino.ino);
+ if (ret) {
+ dout("Failed to parse inode number: %s\n", name);
+ dir = ERR_PTR(ret);
+ goto out;
+ }
+
+ /* And finally the inode */
+ dir = ceph_find_inode(parent->i_sb, vino);
+ if (!dir) {
+ /* This can happen if we're not mounting cephfs on the root */
+ dir = ceph_get_inode(parent->i_sb, vino, NULL);
+ if (!dir)
+ dir = ERR_PTR(-ENOENT);
+ }
+ if (IS_ERR(dir))
+ dout("Can't find inode %s (%s)\n", inode_number, name);
+
+out:
+ kfree(inode_number);
+ return dir;
+}
+
+int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char *buf)
{
+ struct inode *dir = parent;
+ struct qstr iname;
u32 len;
+ int name_len;
int elen;
int ret;
- u8 *cryptbuf;
+ u8 *cryptbuf = NULL;
+
+ iname.name = d_name->name;
+ name_len = d_name->len;
+
+ /* Handle the special case of snapshot names that start with '_' */
+ if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) &&
+ (iname.name[0] == '_')) {
+ dir = parse_longname(parent, iname.name, &name_len);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+ iname.name++; /* skip initial '_' */
+ }
+ iname.len = name_len;
- if (!fscrypt_has_encryption_key(parent)) {
+ if (!fscrypt_has_encryption_key(dir)) {
memcpy(buf, d_name->name, d_name->len);
- return d_name->len;
+ elen = d_name->len;
+ goto out;
}
/*
@@ -207,18 +291,22 @@ int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name,
*
* See: fscrypt_setup_filename
*/
- if (!fscrypt_fname_encrypted_size(parent, d_name->len, NAME_MAX, &len))
- return -ENAMETOOLONG;
+ if (!fscrypt_fname_encrypted_size(dir, iname.len, NAME_MAX, &len)) {
+ elen = -ENAMETOOLONG;
+ goto out;
+ }
/* Allocate a buffer appropriate to hold the result */
cryptbuf = kmalloc(len > CEPH_NOHASH_NAME_MAX ? NAME_MAX : len, GFP_KERNEL);
- if (!cryptbuf)
- return -ENOMEM;
+ if (!cryptbuf) {
+ elen = -ENOMEM;
+ goto out;
+ }
- ret = fscrypt_fname_encrypt(parent, d_name, cryptbuf, len);
+ ret = fscrypt_fname_encrypt(dir, &iname, cryptbuf, len);
if (ret) {
- kfree(cryptbuf);
- return ret;
+ elen = ret;
+ goto out;
}
/* hash the end if the name is long enough */
@@ -234,12 +322,30 @@ int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name,
/* base64 encode the encrypted name */
elen = ceph_base64_encode(cryptbuf, len, buf);
- kfree(cryptbuf);
dout("base64-encoded ciphertext name = %.*s\n", elen, buf);
+
+ /* To understand the 240 limit, see CEPH_NOHASH_NAME_MAX comments */
+ WARN_ON(elen > 240);
+ if ((elen > 0) && (dir != parent)) {
+ char tmp_buf[NAME_MAX];
+
+ elen = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld",
+ elen, buf, dir->i_ino);
+ memcpy(buf, tmp_buf, elen);
+ }
+
+out:
+ kfree(cryptbuf);
+ if (dir != parent) {
+ if ((dir->i_state & I_NEW))
+ discard_new_inode(dir);
+ else
+ iput(dir);
+ }
return elen;
}
-int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentry, char *buf)
+int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, char *buf)
{
WARN_ON_ONCE(!fscrypt_has_encryption_key(parent));
@@ -264,29 +370,42 @@ int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentr
int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
struct fscrypt_str *oname, bool *is_nokey)
{
- int ret;
+ struct inode *dir = fname->dir;
struct fscrypt_str _tname = FSTR_INIT(NULL, 0);
struct fscrypt_str iname;
-
- if (!IS_ENCRYPTED(fname->dir)) {
- oname->name = fname->name;
- oname->len = fname->name_len;
- return 0;
- }
+ char *name = fname->name;
+ int name_len = fname->name_len;
+ int ret;
/* Sanity check that the resulting name will fit in the buffer */
if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX)
return -EIO;
- ret = ceph_fscrypt_prepare_readdir(fname->dir);
- if (ret < 0)
- return ret;
+ /* Handle the special case of snapshot names that start with '_' */
+ if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) &&
+ (name[0] == '_')) {
+ dir = parse_longname(dir, name, &name_len);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+ name++; /* skip initial '_' */
+ }
+
+ if (!IS_ENCRYPTED(dir)) {
+ oname->name = fname->name;
+ oname->len = fname->name_len;
+ ret = 0;
+ goto out_inode;
+ }
+
+ ret = ceph_fscrypt_prepare_readdir(dir);
+ if (ret)
+ goto out_inode;
/*
* Use the raw dentry name as sent by the MDS instead of
* generating a nokey name via fscrypt.
*/
- if (!fscrypt_has_encryption_key(fname->dir)) {
+ if (!fscrypt_has_encryption_key(dir)) {
if (fname->no_copy)
oname->name = fname->name;
else
@@ -294,7 +413,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
oname->len = fname->name_len;
if (is_nokey)
*is_nokey = true;
- return 0;
+ ret = 0;
+ goto out_inode;
}
if (fname->ctext_len == 0) {
@@ -303,11 +423,11 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
if (!tname) {
ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname);
if (ret)
- return ret;
+ goto out_inode;
tname = &_tname;
}
- declen = ceph_base64_decode(fname->name, fname->name_len, tname->name);
+ declen = ceph_base64_decode(name, name_len, tname->name);
if (declen <= 0) {
ret = -EIO;
goto out;
@@ -319,9 +439,25 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
iname.len = fname->ctext_len;
}
- ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname);
+ ret = fscrypt_fname_disk_to_usr(dir, 0, 0, &iname, oname);
+ if (!ret && (dir != fname->dir)) {
+ char tmp_buf[CEPH_BASE64_CHARS(NAME_MAX)];
+
+ name_len = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld",
+ oname->len, oname->name, dir->i_ino);
+ memcpy(oname->name, tmp_buf, name_len);
+ oname->len = name_len;
+ }
+
out:
fscrypt_fname_free_buffer(&_tname);
+out_inode:
+ if ((dir != fname->dir) && !IS_ERR(dir)) {
+ if ((dir->i_state & I_NEW))
+ discard_new_inode(dir);
+ else
+ iput(dir);
+ }
return ret;
}
diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
index 0d0343906d29..d0e88f6d254d 100644
--- a/fs/ceph/crypto.h
+++ b/fs/ceph/crypto.h
@@ -101,8 +101,8 @@ void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc);
int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
struct ceph_acl_sec_ctx *as);
void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as);
-int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, char *buf);
-int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentry, char *buf);
+int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char *buf);
+int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, char *buf);
static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname)
{
--
2.31.1
next prev parent reply other threads:[~2023-02-27 3:34 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-27 3:27 [PATCH v16 00/68] ceph+fscrypt: full support xiubli
2023-02-27 3:27 ` [PATCH v16 01/68] libceph: add spinlock around osd->o_requests xiubli
2023-02-27 3:27 ` [PATCH v16 02/68] libceph: define struct ceph_sparse_extent and add some helpers xiubli
2023-02-27 3:27 ` [PATCH v16 03/68] libceph: add sparse read support to msgr2 crc state machine xiubli
2023-02-27 3:27 ` [PATCH v16 04/68] libceph: add sparse read support to OSD client xiubli
2023-02-27 3:27 ` [PATCH v16 05/68] libceph: support sparse reads on msgr2 secure codepath xiubli
2023-02-27 3:27 ` [PATCH v16 06/68] libceph: add sparse read support to msgr1 xiubli
2023-02-27 3:27 ` [PATCH v16 07/68] ceph: add new mount option to enable sparse reads xiubli
2023-02-27 3:27 ` [PATCH v16 08/68] ceph: preallocate inode for ops that may create one xiubli
2023-02-27 3:27 ` [PATCH v16 09/68] ceph: make ceph_msdc_build_path use ref-walk xiubli
2023-02-27 3:27 ` [PATCH v16 10/68] libceph: add new iov_iter-based ceph_msg_data_type and ceph_osd_data_type xiubli
2023-02-27 3:27 ` [PATCH v16 11/68] ceph: use osd_req_op_extent_osd_iter for netfs reads xiubli
2023-02-27 3:27 ` [PATCH v16 12/68] ceph: fscrypt_auth handling for ceph xiubli
2023-02-27 3:27 ` [PATCH v16 13/68] ceph: ensure that we accept a new context from MDS for new inodes xiubli
2023-02-27 3:27 ` [PATCH v16 14/68] ceph: add support for fscrypt_auth/fscrypt_file to cap messages xiubli
2023-02-27 3:27 ` [PATCH v16 15/68] ceph: implement -o test_dummy_encryption mount option xiubli
2023-02-27 3:27 ` [PATCH v16 16/68] ceph: decode alternate_name in lease info xiubli
2023-02-27 3:27 ` [PATCH v16 17/68] ceph: add fscrypt ioctls xiubli
2023-02-27 3:27 ` [PATCH v16 18/68] ceph: make the ioctl cmd more readable in debug log xiubli
2023-02-27 3:27 ` [PATCH v16 19/68] ceph: add base64 endcoding routines for encrypted names xiubli
2023-02-27 3:27 ` [PATCH v16 20/68] ceph: add encrypted fname handling to ceph_mdsc_build_path xiubli
2023-02-27 3:27 ` [PATCH v16 21/68] ceph: send altname in MClientRequest xiubli
2023-02-27 3:27 ` [PATCH v16 22/68] ceph: encode encrypted name in dentry release xiubli
2023-02-27 3:27 ` [PATCH v16 23/68] ceph: properly set DCACHE_NOKEY_NAME flag in lookup xiubli
2023-02-27 3:27 ` [PATCH v16 24/68] ceph: set DCACHE_NOKEY_NAME in atomic open xiubli
2023-02-27 3:27 ` [PATCH v16 25/68] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries xiubli
2023-03-07 18:53 ` Luís Henriques
2023-03-08 1:50 ` Xiubo Li
2023-03-08 9:29 ` Luís Henriques
2023-03-08 10:42 ` Xiubo Li
2023-03-08 17:14 ` Luís Henriques
2023-03-08 17:54 ` Jeff Layton
2023-03-08 18:30 ` Luís Henriques
2023-03-08 19:32 ` Jeff Layton
2023-03-09 9:52 ` Luís Henriques
2023-03-09 7:06 ` Xiubo Li
2023-03-09 9:55 ` Luís Henriques
2023-03-09 11:41 ` Xiubo Li
2023-02-27 3:27 ` [PATCH v16 26/68] ceph: add helpers for converting names for userland presentation xiubli
2023-02-27 3:27 ` [PATCH v16 27/68] ceph: fix base64 encoded name's length check in ceph_fname_to_usr() xiubli
2023-02-27 3:27 ` [PATCH v16 28/68] ceph: add fscrypt support to ceph_fill_trace xiubli
2023-02-27 3:27 ` [PATCH v16 29/68] ceph: pass the request to parse_reply_info_readdir() xiubli
2023-02-27 3:27 ` [PATCH v16 30/68] ceph: add ceph_encode_encrypted_dname() helper xiubli
2023-02-27 3:27 ` [PATCH v16 31/68] ceph: add support to readdir for encrypted filenames xiubli
2023-02-27 3:27 ` [PATCH v16 32/68] ceph: create symlinks with encrypted and base64-encoded targets xiubli
2023-02-27 3:27 ` [PATCH v16 33/68] ceph: make ceph_get_name decrypt filenames xiubli
2023-02-27 3:27 ` [PATCH v16 34/68] ceph: add a new ceph.fscrypt.auth vxattr xiubli
2023-02-27 3:27 ` [PATCH v16 35/68] ceph: add some fscrypt guardrails xiubli
2023-02-27 3:27 ` [PATCH v16 36/68] ceph: allow encrypting a directory while not having Ax caps xiubli
2023-02-27 3:27 ` [PATCH v16 37/68] ceph: mark directory as non-complete after loading key xiubli
2023-02-27 3:27 ` [PATCH v16 38/68] ceph: don't allow changing layout on encrypted files/directories xiubli
2023-02-27 3:27 ` [PATCH v16 39/68] libceph: add CEPH_OSD_OP_ASSERT_VER support xiubli
2023-02-27 3:27 ` [PATCH v16 40/68] ceph: size handling for encrypted inodes in cap updates xiubli
2023-02-27 3:27 ` [PATCH v16 41/68] ceph: fscrypt_file field handling in MClientRequest messages xiubli
2023-02-27 3:27 ` [PATCH v16 42/68] ceph: get file size from fscrypt_file when present in inode traces xiubli
2023-02-27 3:27 ` [PATCH v16 43/68] ceph: handle fscrypt fields in cap messages from MDS xiubli
2023-02-27 3:27 ` [PATCH v16 44/68] ceph: update WARN_ON message to pr_warn xiubli
2023-02-27 3:27 ` [PATCH v16 45/68] ceph: add __ceph_get_caps helper support xiubli
2023-02-27 3:27 ` [PATCH v16 46/68] ceph: add __ceph_sync_read " xiubli
2023-02-27 3:27 ` [PATCH v16 47/68] ceph: add object version support for sync read xiubli
2023-02-27 3:27 ` [PATCH v16 48/68] ceph: add infrastructure for file encryption and decryption xiubli
2023-02-27 3:27 ` [PATCH v16 49/68] ceph: add truncate size handling support for fscrypt xiubli
2023-02-27 3:27 ` [PATCH v16 50/68] libceph: allow ceph_osdc_new_request to accept a multi-op read xiubli
2023-02-27 3:27 ` [PATCH v16 51/68] ceph: disable fallocate for encrypted inodes xiubli
2023-02-27 3:27 ` [PATCH v16 52/68] ceph: disable copy offload on " xiubli
2023-02-27 3:27 ` [PATCH v16 53/68] ceph: don't use special DIO path for " xiubli
2023-02-27 3:27 ` [PATCH v16 54/68] ceph: align data in pages in ceph_sync_write xiubli
2023-02-27 3:28 ` [PATCH v16 55/68] ceph: add read/modify/write to ceph_sync_write xiubli
2023-02-27 3:28 ` [PATCH v16 56/68] ceph: plumb in decryption during sync reads xiubli
2023-02-27 3:28 ` [PATCH v16 57/68] ceph: add fscrypt decryption support to ceph_netfs_issue_op xiubli
2023-02-27 3:28 ` [PATCH v16 58/68] ceph: set i_blkbits to crypto block size for encrypted inodes xiubli
2023-02-27 3:28 ` [PATCH v16 59/68] ceph: add encryption support to writepage xiubli
2023-02-27 3:28 ` [PATCH v16 60/68] ceph: fscrypt support for writepages xiubli
2023-02-27 3:28 ` [PATCH v16 61/68] ceph: invalidate pages when doing direct/sync writes xiubli
2023-02-27 3:28 ` [PATCH v16 62/68] ceph: add support for encrypted snapshot names xiubli
2023-02-27 3:28 ` xiubli [this message]
2023-02-27 3:28 ` [PATCH v16 64/68] ceph: update documentation regarding snapshot naming limitations xiubli
2023-02-27 3:28 ` [PATCH v16 65/68] ceph: prevent snapshots to be created in encrypted locked directories xiubli
2023-02-27 3:28 ` [PATCH v16 66/68] ceph: report STATX_ATTR_ENCRYPTED on encrypted inodes xiubli
2023-02-27 3:28 ` [PATCH v16 67/68] libceph: defer removing the req from osdc just after req->r_callback xiubli
2023-02-27 3:28 ` [PATCH v16 68/68] ceph: drop the messages from MDS when unmounting xiubli
2023-02-27 9:27 ` [PATCH v16 00/68] ceph+fscrypt: full support Luís Henriques
2023-02-27 9:58 ` Xiubo Li
2023-02-27 10:30 ` Luís Henriques
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