[PATCH AUTOSEL 6.6 37/40] smb: client: implement ->query_reparse_point() for SMB1

From: Sasha Levin
Date: Tue Nov 28 2023 - 16:13:50 EST

From: Paulo Alcantara <pc@xxxxxxxxxxxxx>

[ Upstream commit ed3e0a149b58ea8cfd10cc4f7cefb39877ff07ac ]

Reparse points are not limited to symlinks, so implement
->query_reparse_point() in order to handle different file types.

Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/smb/client/cifspdu.h | 2 +-
fs/smb/client/cifsproto.h | 9 ++
fs/smb/client/cifssmb.c | 193 +++++++++++++++-----------------------
fs/smb/client/smb1ops.c | 49 ++--------
fs/smb/client/smb2ops.c | 35 ++++---
5 files changed, 113 insertions(+), 175 deletions(-)

diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h
index e17222fec9d29..efaf22c42ed00 100644
--- a/fs/smb/client/cifspdu.h
+++ b/fs/smb/client/cifspdu.h
@@ -1356,7 +1356,7 @@ typedef struct smb_com_transaction_ioctl_rsp {
__le32 DataDisplacement;
__u8 SetupCount; /* 1 */
__le16 ReturnedDataLen;
- __u16 ByteCount;
+ __le16 ByteCount;
} __attribute__((packed)) TRANSACT_IOCTL_RSP;

#define CIFS_ACL_OWNER 1
diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 0c37eefa18a57..a51b4308da9d7 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -457,6 +457,12 @@ extern int CIFSSMBUnixQuerySymLink(const unsigned int xid,
struct cifs_tcon *tcon,
const unsigned char *searchName, char **syminfo,
const struct nls_table *nls_codepage, int remap);
+extern int cifs_query_reparse_point(const unsigned int xid,
+ struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb,
+ const char *full_path,
+ u32 *tag, struct kvec *rsp,
+ int *rsp_buftype);
extern int CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
__u16 fid, char **symlinkinfo,
const struct nls_table *nls_codepage);
@@ -656,6 +662,9 @@ void cifs_put_tcp_super(struct super_block *sb);
int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix);
char *extract_hostname(const char *unc);
char *extract_sharename(const char *unc);
+int parse_reparse_point(struct reparse_data_buffer *buf,
+ u32 plen, struct cifs_sb_info *cifs_sb,
+ bool unicode, char **target_path);

#ifdef CONFIG_CIFS_DFS_UPCALL
static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index 25503f1a4fd21..bad91ba6c3a9c 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -2690,136 +2690,97 @@ CIFSSMBUnixQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
return rc;
}

-/*
- * Recent Windows versions now create symlinks more frequently
- * and they use the "reparse point" mechanism below. We can of course
- * do symlinks nicely to Samba and other servers which support the
- * CIFS Unix Extensions and we can also do SFU symlinks and "client only"
- * "MF" symlinks optionally, but for recent Windows we really need to
- * reenable the code below and fix the cifs_symlink callers to handle this.
- * In the interim this code has been moved to its own config option so
- * it is not compiled in by default until callers fixed up and more tested.
- */
-int
-CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
- __u16 fid, char **symlinkinfo,
- const struct nls_table *nls_codepage)
+int cifs_query_reparse_point(const unsigned int xid,
+ struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb,
+ const char *full_path,
+ u32 *tag, struct kvec *rsp,
+ int *rsp_buftype)
{
- int rc = 0;
- int bytes_returned;
- struct smb_com_transaction_ioctl_req *pSMB;
- struct smb_com_transaction_ioctl_rsp *pSMBr;
- bool is_unicode;
- unsigned int sub_len;
- char *sub_start;
- struct reparse_symlink_data *reparse_buf;
- struct reparse_posix_data *posix_buf;
+ struct cifs_open_parms oparms;
+ TRANSACT_IOCTL_REQ *io_req = NULL;
+ TRANSACT_IOCTL_RSP *io_rsp = NULL;
+ struct cifs_fid fid;
__u32 data_offset, data_count;
- char *end_of_smb;
+ __u8 *start, *end;
+ int io_rsp_len;
+ int oplock = 0;
+ int rc;

- cifs_dbg(FYI, "In Windows reparse style QueryLink for fid %u\n", fid);
- rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon, (void **) &pSMB,
- (void **) &pSMBr);
+ cifs_tcon_dbg(FYI, "%s: path=%s\n", __func__, full_path);
+
+ if (cap_unix(tcon->ses))
+ return -EOPNOTSUPP;
+
+ oparms = (struct cifs_open_parms) {
+ .tcon = tcon,
+ .cifs_sb = cifs_sb,
+ .desired_access = FILE_READ_ATTRIBUTES,
+ .create_options = cifs_create_options(cifs_sb,
+ OPEN_REPARSE_POINT),
+ .disposition = FILE_OPEN,
+ .path = full_path,
+ .fid = &fid,
+ };
+
+ rc = CIFS_open(xid, &oparms, &oplock, NULL);
if (rc)
return rc;

- pSMB->TotalParameterCount = 0 ;
- pSMB->TotalDataCount = 0;
- pSMB->MaxParameterCount = cpu_to_le32(2);
- /* BB find exact data count max from sess structure BB */
- pSMB->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00);
- pSMB->MaxSetupCount = 4;
- pSMB->Reserved = 0;
- pSMB->ParameterOffset = 0;
- pSMB->DataCount = 0;
- pSMB->DataOffset = 0;
- pSMB->SetupCount = 4;
- pSMB->SubCommand = cpu_to_le16(NT_TRANSACT_IOCTL);
- pSMB->ParameterCount = pSMB->TotalParameterCount;
- pSMB->FunctionCode = cpu_to_le32(FSCTL_GET_REPARSE_POINT);
- pSMB->IsFsctl = 1; /* FSCTL */
- pSMB->IsRootFlag = 0;
- pSMB->Fid = fid; /* file handle always le */
- pSMB->ByteCount = 0;
+ rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon,
+ (void **)&io_req, (void **)&io_rsp);
+ if (rc)
+ goto error;

- rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
- (struct smb_hdr *) pSMBr, &bytes_returned, 0);
- if (rc) {
- cifs_dbg(FYI, "Send error in QueryReparseLinkInfo = %d\n", rc);
- goto qreparse_out;
- }
+ io_req->TotalParameterCount = 0;
+ io_req->TotalDataCount = 0;
+ io_req->MaxParameterCount = cpu_to_le32(2);
+ /* BB find exact data count max from sess structure BB */
+ io_req->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00);
+ io_req->MaxSetupCount = 4;
+ io_req->Reserved = 0;
+ io_req->ParameterOffset = 0;
+ io_req->DataCount = 0;
+ io_req->DataOffset = 0;
+ io_req->SetupCount = 4;
+ io_req->SubCommand = cpu_to_le16(NT_TRANSACT_IOCTL);
+ io_req->ParameterCount = io_req->TotalParameterCount;
+ io_req->FunctionCode = cpu_to_le32(FSCTL_GET_REPARSE_POINT);
+ io_req->IsFsctl = 1;
+ io_req->IsRootFlag = 0;
+ io_req->Fid = fid.netfid;
+ io_req->ByteCount = 0;
+
+ rc = SendReceive(xid, tcon->ses, (struct smb_hdr *)io_req,
+ (struct smb_hdr *)io_rsp, &io_rsp_len, 0);
+ if (rc)
+ goto error;

- data_offset = le32_to_cpu(pSMBr->DataOffset);
- data_count = le32_to_cpu(pSMBr->DataCount);
- if (get_bcc(&pSMBr->hdr) < 2 || data_offset > 512) {
- /* BB also check enough total bytes returned */
- rc = -EIO; /* bad smb */
- goto qreparse_out;
- }
- if (!data_count || (data_count > 2048)) {
+ data_offset = le32_to_cpu(io_rsp->DataOffset);
+ data_count = le32_to_cpu(io_rsp->DataCount);
+ if (get_bcc(&io_rsp->hdr) < 2 || data_offset > 512 ||
+ !data_count || data_count > 2048) {
rc = -EIO;
- cifs_dbg(FYI, "Invalid return data count on get reparse info ioctl\n");
- goto qreparse_out;
- }
- end_of_smb = 2 + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
- reparse_buf = (struct reparse_symlink_data *)
- ((char *)&pSMBr->hdr.Protocol + data_offset);
- if ((char *)reparse_buf >= end_of_smb) {
- rc = -EIO;
- goto qreparse_out;
- }
- if (reparse_buf->ReparseTag == cpu_to_le32(IO_REPARSE_TAG_NFS)) {
- cifs_dbg(FYI, "NFS style reparse tag\n");
- posix_buf = (struct reparse_posix_data *)reparse_buf;
-
- if (posix_buf->InodeType != cpu_to_le64(NFS_SPECFILE_LNK)) {
- cifs_dbg(FYI, "unsupported file type 0x%llx\n",
- le64_to_cpu(posix_buf->InodeType));
- rc = -EOPNOTSUPP;
- goto qreparse_out;
- }
- is_unicode = true;
- sub_len = le16_to_cpu(reparse_buf->ReparseDataLength);
- if (posix_buf->PathBuffer + sub_len > end_of_smb) {
- cifs_dbg(FYI, "reparse buf beyond SMB\n");
- rc = -EIO;
- goto qreparse_out;
- }
- *symlinkinfo = cifs_strndup_from_utf16(posix_buf->PathBuffer,
- sub_len, is_unicode, nls_codepage);
- goto qreparse_out;
- } else if (reparse_buf->ReparseTag !=
- cpu_to_le32(IO_REPARSE_TAG_SYMLINK)) {
- rc = -EOPNOTSUPP;
- goto qreparse_out;
+ goto error;
}

- /* Reparse tag is NTFS symlink */
- sub_start = le16_to_cpu(reparse_buf->SubstituteNameOffset) +
- reparse_buf->PathBuffer;
- sub_len = le16_to_cpu(reparse_buf->SubstituteNameLength);
- if (sub_start + sub_len > end_of_smb) {
- cifs_dbg(FYI, "reparse buf beyond SMB\n");
+ end = 2 + get_bcc(&io_rsp->hdr) + (__u8 *)&io_rsp->ByteCount;
+ start = (__u8 *)&io_rsp->hdr.Protocol + data_offset;
+ if (start >= end) {
rc = -EIO;
- goto qreparse_out;
+ goto error;
}
- if (pSMBr->hdr.Flags2 & SMBFLG2_UNICODE)
- is_unicode = true;
- else
- is_unicode = false;
-
- /* BB FIXME investigate remapping reserved chars here */
- *symlinkinfo = cifs_strndup_from_utf16(sub_start, sub_len, is_unicode,
- nls_codepage);
- if (!*symlinkinfo)
- rc = -ENOMEM;
-qreparse_out:
- cifs_buf_release(pSMB);

- /*
- * Note: On -EAGAIN error only caller can retry on handle based calls
- * since file handle passed in no longer valid.
- */
+ *tag = le32_to_cpu(((struct reparse_data_buffer *)start)->ReparseTag);
+ rsp->iov_base = io_rsp;
+ rsp->iov_len = io_rsp_len;
+ *rsp_buftype = CIFS_LARGE_BUFFER;
+ CIFSSMBClose(xid, tcon, fid.netfid);
+ return 0;
+
+error:
+ cifs_buf_release(io_req);
+ CIFSSMBClose(xid, tcon, fid.netfid);
return rc;
}

diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
index 9bf8735cdd1e8..6b4d8effa79df 100644
--- a/fs/smb/client/smb1ops.c
+++ b/fs/smb/client/smb1ops.c
@@ -979,18 +979,13 @@ static int cifs_query_symlink(const unsigned int xid,
char **target_path,
struct kvec *rsp_iov)
{
+ struct reparse_data_buffer *buf;
+ TRANSACT_IOCTL_RSP *io = rsp_iov->iov_base;
+ bool unicode = !!(io->hdr.Flags2 & SMBFLG2_UNICODE);
+ u32 plen = le16_to_cpu(io->ByteCount);
int rc;
- int oplock = 0;
- bool is_reparse_point = !!rsp_iov;
- struct cifs_fid fid;
- struct cifs_open_parms oparms;

- cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path);
-
- if (is_reparse_point) {
- cifs_dbg(VFS, "reparse points not handled for SMB1 symlinks\n");
- return -EOPNOTSUPP;
- }
+ cifs_tcon_dbg(FYI, "%s: path=%s\n", __func__, full_path);

/* Check for unix extensions */
if (cap_unix(tcon->ses)) {
@@ -1001,37 +996,12 @@ static int cifs_query_symlink(const unsigned int xid,
rc = cifs_unix_dfs_readlink(xid, tcon, full_path,
target_path,
cifs_sb->local_nls);
-
- goto out;
+ return rc;
}

- oparms = (struct cifs_open_parms) {
- .tcon = tcon,
- .cifs_sb = cifs_sb,
- .desired_access = FILE_READ_ATTRIBUTES,
- .create_options = cifs_create_options(cifs_sb,
- OPEN_REPARSE_POINT),
- .disposition = FILE_OPEN,
- .path = full_path,
- .fid = &fid,
- };
-
- rc = CIFS_open(xid, &oparms, &oplock, NULL);
- if (rc)
- goto out;
-
- rc = CIFSSMBQuerySymLink(xid, tcon, fid.netfid, target_path,
- cifs_sb->local_nls);
- if (rc)
- goto out_close;
-
- convert_delimiter(*target_path, '/');
-out_close:
- CIFSSMBClose(xid, tcon, fid.netfid);
-out:
- if (!rc)
- cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);
- return rc;
+ buf = (struct reparse_data_buffer *)((__u8 *)&io->hdr.Protocol +
+ le32_to_cpu(io->DataOffset));
+ return parse_reparse_point(buf, plen, cifs_sb, unicode, target_path);
}

static bool
@@ -1214,6 +1184,7 @@ struct smb_version_operations smb1_operations = {
.is_path_accessible = cifs_is_path_accessible,
.can_echo = cifs_can_echo,
.query_path_info = cifs_query_path_info,
+ .query_reparse_point = cifs_query_reparse_point,
.query_file_info = cifs_query_file_info,
.get_srv_inum = cifs_get_srv_inum,
.set_path_size = CIFSSMBSetEOF,
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 9aeecee6b91b3..abc0792698349 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -2886,27 +2886,26 @@ parse_reparse_posix(struct reparse_posix_data *symlink_buf,
return 0;
}

-static int
-parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
- u32 plen, char **target_path,
- struct cifs_sb_info *cifs_sb)
+static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
+ u32 plen, bool unicode, char **target_path,
+ struct cifs_sb_info *cifs_sb)
{
unsigned int sub_len;
unsigned int sub_offset;

/* We handle Symbolic Link reparse tag here. See: MS-FSCC 2.1.2.4 */

- sub_offset = le16_to_cpu(symlink_buf->SubstituteNameOffset);
- sub_len = le16_to_cpu(symlink_buf->SubstituteNameLength);
+ sub_offset = le16_to_cpu(sym->SubstituteNameOffset);
+ sub_len = le16_to_cpu(sym->SubstituteNameLength);
if (sub_offset + 20 > plen ||
sub_offset + sub_len + 20 > plen) {
cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
return -EIO;
}

- *target_path = cifs_strndup_from_utf16(
- symlink_buf->PathBuffer + sub_offset,
- sub_len, true, cifs_sb->local_nls);
+ *target_path = cifs_strndup_from_utf16(sym->PathBuffer + sub_offset,
+ sub_len, unicode,
+ cifs_sb->local_nls);
if (!(*target_path))
return -ENOMEM;

@@ -2916,19 +2915,17 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
return 0;
}

-static int
-parse_reparse_point(struct reparse_data_buffer *buf,
- u32 plen, char **target_path,
- struct cifs_sb_info *cifs_sb)
+int parse_reparse_point(struct reparse_data_buffer *buf,
+ u32 plen, struct cifs_sb_info *cifs_sb,
+ bool unicode, char **target_path)
{
- if (plen < sizeof(struct reparse_data_buffer)) {
+ if (plen < sizeof(*buf)) {
cifs_dbg(VFS, "reparse buffer is too small. Must be at least 8 bytes but was %d\n",
plen);
return -EIO;
}

- if (plen < le16_to_cpu(buf->ReparseDataLength) +
- sizeof(struct reparse_data_buffer)) {
+ if (plen < le16_to_cpu(buf->ReparseDataLength) + sizeof(*buf)) {
cifs_dbg(VFS, "srv returned invalid reparse buf length: %d\n",
plen);
return -EIO;
@@ -2943,7 +2940,7 @@ parse_reparse_point(struct reparse_data_buffer *buf,
case IO_REPARSE_TAG_SYMLINK:
return parse_reparse_symlink(
(struct reparse_symlink_data_buffer *)buf,
- plen, target_path, cifs_sb);
+ plen, unicode, target_path, cifs_sb);
default:
cifs_dbg(VFS, "srv returned unknown symlink buffer tag:0x%08x\n",
le32_to_cpu(buf->ReparseTag));
@@ -2962,11 +2959,11 @@ static int smb2_query_symlink(const unsigned int xid,
struct smb2_ioctl_rsp *io = rsp_iov->iov_base;
u32 plen = le32_to_cpu(io->OutputCount);

- cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path);
+ cifs_tcon_dbg(FYI, "%s: path: %s\n", __func__, full_path);

buf = (struct reparse_data_buffer *)((u8 *)io +
le32_to_cpu(io->OutputOffset));
- return parse_reparse_point(buf, plen, target_path, cifs_sb);
+ return parse_reparse_point(buf, plen, cifs_sb, true, target_path);
}

static int smb2_query_reparse_point(const unsigned int xid,
--
2.42.0