From d244bf2dfbebfded05f494ffd53659fa7b1e32c1 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Wed, 14 Aug 2013 19:25:22 +0400 Subject: CIFS: Implement follow_link for nounix CIFS mounts by using a query reparse ioctl request. Acked-by: Jeff Layton Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 110 +++++++++++++++++++++++++----------------------------- 1 file changed, 51 insertions(+), 59 deletions(-) (limited to 'fs/cifs/cifssmb.c') 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 -- cgit v1.2.3