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authorPavel Shilovsky <pshilovsky@samba.org>2013-08-14 19:25:22 +0400
committerSteve French <smfrench@gmail.com>2013-09-08 23:27:41 +0400
commitd244bf2dfbebfded05f494ffd53659fa7b1e32c1 (patch)
tree7dde97c81405cf271463025cb7f42f1b52e282bb /fs/cifs/cifssmb.c
parentb42bf88828cde60772dc08201d0a4f1a0663d7bc (diff)
downloadlinux-d244bf2dfbebfded05f494ffd53659fa7b1e32c1.tar.xz
CIFS: Implement follow_link for nounix CIFS mounts
by using a query reparse ioctl request. Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs/cifssmb.c')
-rw-r--r--fs/cifs/cifssmb.c110
1 files changed, 51 insertions, 59 deletions
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index a89c4cb4e6cf..a3d74fea1623 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -3067,7 +3067,6 @@ querySymLinkRetry:
return rc;
}
-#ifdef CONFIG_CIFS_SYMLINK_EXPERIMENTAL
/*
* Recent Windows versions now create symlinks more frequently
* and they use the "reparse point" mechanism below. We can of course
@@ -3079,18 +3078,22 @@ querySymLinkRetry:
* it is not compiled in by default until callers fixed up and more tested.
*/
int
-CIFSSMBQueryReparseLinkInfo(const unsigned int xid, struct cifs_tcon *tcon,
- const unsigned char *searchName,
- char *symlinkinfo, const int buflen, __u16 fid,
- const struct nls_table *nls_codepage)
+CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
+ __u16 fid, char **symlinkinfo,
+ const struct nls_table *nls_codepage)
{
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_data *reparse_buf;
+ __u32 data_offset, data_count;
+ char *end_of_smb;
- cifs_dbg(FYI, "In Windows reparse style QueryLink for path %s\n",
- searchName);
+ 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);
if (rc)
@@ -3119,66 +3122,55 @@ CIFSSMBQueryReparseLinkInfo(const unsigned int xid, struct cifs_tcon *tcon,
(struct smb_hdr *) pSMBr, &bytes_returned, 0);
if (rc) {
cifs_dbg(FYI, "Send error in QueryReparseLinkInfo = %d\n", rc);
- } else { /* decode response */
- __u32 data_offset = le32_to_cpu(pSMBr->DataOffset);
- __u32 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)) {
- char *end_of_smb = 2 /* sizeof byte count */ +
- get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
-
- struct reparse_data *reparse_buf =
- (struct reparse_data *)
- ((char *)&pSMBr->hdr.Protocol
- + data_offset);
- if ((char *)reparse_buf >= end_of_smb) {
- rc = -EIO;
- goto qreparse_out;
- }
- if ((reparse_buf->LinkNamesBuf +
- reparse_buf->TargetNameOffset +
- reparse_buf->TargetNameLen) > end_of_smb) {
- cifs_dbg(FYI, "reparse buf beyond SMB\n");
- rc = -EIO;
- goto qreparse_out;
- }
+ goto qreparse_out;
+ }
- if (pSMBr->hdr.Flags2 & SMBFLG2_UNICODE) {
- cifs_from_ucs2(symlinkinfo, (__le16 *)
- (reparse_buf->LinkNamesBuf +
- reparse_buf->TargetNameOffset),
- buflen,
- reparse_buf->TargetNameLen,
- nls_codepage, 0);
- } else { /* ASCII names */
- strncpy(symlinkinfo,
- reparse_buf->LinkNamesBuf +
- reparse_buf->TargetNameOffset,
- min_t(const int, buflen,
- reparse_buf->TargetNameLen));
- }
- } else {
- rc = -EIO;
- cifs_dbg(FYI, "Invalid return data count on get reparse info ioctl\n");
- }
- symlinkinfo[buflen] = 0; /* just in case so the caller
- does not go off the end of the buffer */
- cifs_dbg(FYI, "readlink result - %s\n", symlinkinfo);
+ 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)) {
+ 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_data *)
+ ((char *)&pSMBr->hdr.Protocol + data_offset);
+ if ((char *)reparse_buf >= end_of_smb) {
+ rc = -EIO;
+ goto qreparse_out;
}
+ if ((reparse_buf->PathBuffer + reparse_buf->PrintNameOffset +
+ reparse_buf->PrintNameLength) > end_of_smb) {
+ cifs_dbg(FYI, "reparse buf beyond SMB\n");
+ rc = -EIO;
+ goto qreparse_out;
+ }
+ sub_start = reparse_buf->SubstituteNameOffset + reparse_buf->PathBuffer;
+ sub_len = reparse_buf->SubstituteNameLength;
+ 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 */
-
+ /*
+ * Note: On -EAGAIN error only caller can retry on handle based calls
+ * since file handle passed in no longer valid.
+ */
return rc;
}
-#endif /* CIFS_SYMLINK_EXPERIMENTAL */ /* BB temporarily unused */
#ifdef CONFIG_CIFS_POSIX