cifs: keep BCC in little-endian format

This is the same patch as originally posted, just with some merge
conflicts fixed up...

Currently, the ByteCount is usually converted to host-endian on receive.
This is confusing however, as we need to keep two sets of routines for
accessing it, and keep track of when to use each routine. Munging
received packets like this also limits when the signature can be
calulated.

Simplify the code by keeping the received ByteCount in little-endian
format. This allows us to eliminate a set of routines for accessing it
and we can now drop the *_le suffixes from the accessor functions since
that's now implied.

While we're at it, switch all of the places that read the ByteCount
directly to use the get_bcc inline which should also clean up some
unaligned accesses.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 32 insertions, 30 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 88004094ebd1..83df937b814e 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -582,7 +582,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 
         if ((pSMBr->hdr.Flags2 & SMBFLG2_EXT_SEC) &&
                 (server->capabilities & CAP_EXTENDED_SECURITY)) {
-                count = pSMBr->ByteCount;
+                count = get_bcc(&pSMBr->hdr);
                 if (count < 16) {
                         rc = -EIO;
                         goto neg_err_exit;
@@ -736,7 +736,7 @@ CIFSSMBEcho(struct TCP_Server_Info *server)
         smb->hdr.Tid = 0xffff;
         smb->hdr.WordCount = 1;
         put_unaligned_le16(1, &smb->EchoCount);
-        put_bcc_le(1, &smb->hdr);
+        put_bcc(1, &smb->hdr);
         smb->Data[0] = 'a';
         inc_rfc1001_len(smb, 3);
 
@@ -1079,7 +1079,7 @@ PsxCreat:
         cFYI(1, "copying inode info");
         rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-        if (rc || (pSMBr->ByteCount < sizeof(OPEN_PSX_RSP))) {
+        if (rc || get_bcc(&pSMBr->hdr) < sizeof(OPEN_PSX_RSP)) {
                 rc = -EIO;      /* bad smb */
                 goto psx_create_err;
         }
@@ -1100,7 +1100,7 @@ PsxCreat:
                 pRetData->Type = cpu_to_le32(-1); /* unknown */
                 cFYI(DBG2, "unknown type");
         } else {
-                if (pSMBr->ByteCount < sizeof(OPEN_PSX_RSP)
+                if (get_bcc(&pSMBr->hdr) < sizeof(OPEN_PSX_RSP)
                                         + sizeof(FILE_UNIX_BASIC_INFO)) {
                         cERROR(1, "Open response data too small");
                         pRetData->Type = cpu_to_le32(-1);
@@ -1867,7 +1867,7 @@ CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
                 __u16 data_count;
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < sizeof(struct cifs_posix_lock))) {
+                if (rc || get_bcc(&pSMBr->hdr) < sizeof(*parm_data)) {
                         rc = -EIO;      /* bad smb */
                         goto plk_err_exit;
                 }
@@ -2494,7 +2494,7 @@ querySymLinkRetry:
 
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
                 /* BB also check enough total bytes returned */
-                if (rc || (pSMBr->ByteCount < 2))
+                if (rc || get_bcc(&pSMBr->hdr) < 2)
                         rc = -EIO;
                 else {
                         bool is_unicode;
@@ -2576,14 +2576,14 @@ CIFSSMBQueryReparseLinkInfo(const int xid, struct cifsTconInfo *tcon,
         } else {                /* decode response */
                 __u32 data_offset = le32_to_cpu(pSMBr->DataOffset);
                 __u32 data_count = le32_to_cpu(pSMBr->DataCount);
-                if ((pSMBr->ByteCount < 2) || (data_offset > 512)) {
-                /* BB also check enough total bytes returned */
+                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 */ +
-                                pSMBr->ByteCount + (char *)&pSMBr->ByteCount;
+                               get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
 
                         struct reparse_data *reparse_buf =
                                                 (struct reparse_data *)
@@ -2841,8 +2841,8 @@ queryAclRetry:
                 /* decode response */
 
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
-                if (rc || (pSMBr->ByteCount < 2))
                 /* BB also check enough total bytes returned */
+                if (rc || get_bcc(&pSMBr->hdr) < 2)
                         rc = -EIO;      /* bad smb */
                 else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -2991,8 +2991,8 @@ GetExtAttrRetry:
         } else {
                 /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
-                if (rc || (pSMBr->ByteCount < 2))
                 /* BB also check enough total bytes returned */
+                if (rc || get_bcc(&pSMBr->hdr) < 2)
                         /* If rc should we check for EOPNOSUPP and
                            disable the srvino flag? or in caller? */
                         rc = -EIO;      /* bad smb */
@@ -3067,6 +3067,7 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
         char *end_of_smb;
         __u32 data_count, data_offset, parm_count, parm_offset;
         struct smb_com_ntransact_rsp *pSMBr;
+        u16 bcc;
 
         *pdatalen = 0;
         *pparmlen = 0;
@@ -3076,8 +3077,8 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
 
         pSMBr = (struct smb_com_ntransact_rsp *)buf;
 
-        /* ByteCount was converted from little endian in SendReceive */
-        end_of_smb = 2 /* sizeof byte count */ + pSMBr->ByteCount +
+        bcc = get_bcc(&pSMBr->hdr);
+        end_of_smb = 2 /* sizeof byte count */ + bcc +
                         (char *)&pSMBr->ByteCount;
 
         data_offset = le32_to_cpu(pSMBr->DataOffset);
@@ -3103,7 +3104,7 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
                         *ppdata, data_count, (data_count + *ppdata),
                         end_of_smb, pSMBr);
                 return -EINVAL;
-        } else if (parm_count + data_count > pSMBr->ByteCount) {
+        } else if (parm_count + data_count > bcc) {
                 cFYI(1, "parm count and data count larger than SMB");
                 return -EINVAL;
         }
@@ -3389,7 +3390,7 @@ QFileInfoRetry:
 
                 if (rc) /* BB add auto retry on EOPNOTSUPP? */
                         rc = -EIO;
-                else if (pSMBr->ByteCount < 40)
+                else if (get_bcc(&pSMBr->hdr) < 40)
                         rc = -EIO;      /* bad smb */
                 else if (pFindData) {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -3477,9 +3478,9 @@ QPathInfoRetry:
 
                 if (rc) /* BB add auto retry on EOPNOTSUPP? */
                         rc = -EIO;
-                else if (!legacy && (pSMBr->ByteCount < 40))
+                else if (!legacy && get_bcc(&pSMBr->hdr) < 40)
                         rc = -EIO;      /* bad smb */
-                else if (legacy && (pSMBr->ByteCount < 24))
+                else if (legacy && get_bcc(&pSMBr->hdr) < 24)
                         rc = -EIO;  /* 24 or 26 expected but we do not read
                                         last field */
                 else if (pFindData) {
@@ -3555,7 +3556,7 @@ UnixQFileInfoRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < sizeof(FILE_UNIX_BASIC_INFO))) {
+                if (rc || get_bcc(&pSMBr->hdr) < sizeof(FILE_UNIX_BASIC_INFO)) {
                         cERROR(1, "Malformed FILE_UNIX_BASIC_INFO response.\n"
                                    "Unix Extensions can be disabled on mount "
                                    "by specifying the nosfu mount option.");
@@ -3641,7 +3642,7 @@ UnixQPathInfoRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < sizeof(FILE_UNIX_BASIC_INFO))) {
+                if (rc || get_bcc(&pSMBr->hdr) < sizeof(FILE_UNIX_BASIC_INFO)) {
                         cERROR(1, "Malformed FILE_UNIX_BASIC_INFO response.\n"
                                    "Unix Extensions can be disabled on mount "
                                    "by specifying the nosfu mount option.");
@@ -4046,8 +4047,8 @@ GetInodeNumberRetry:
         } else {
                 /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
-                if (rc || (pSMBr->ByteCount < 2))
                 /* BB also check enough total bytes returned */
+                if (rc || get_bcc(&pSMBr->hdr) < 2)
                         /* If rc should we check for EOPNOSUPP and
                         disable the srvino flag? or in caller? */
                         rc = -EIO;      /* bad smb */
@@ -4272,13 +4273,13 @@ getDFSRetry:
         rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
         /* BB Also check if enough total bytes returned? */
-        if (rc || (pSMBr->ByteCount < 17)) {
+        if (rc || get_bcc(&pSMBr->hdr) < 17) {
                 rc = -EIO;      /* bad smb */
                 goto GetDFSRefExit;
         }
 
         cFYI(1, "Decoding GetDFSRefer response BCC: %d  Offset %d",
-                                pSMBr->ByteCount,
+                                get_bcc(&pSMBr->hdr),
                                 le16_to_cpu(pSMBr->t2.DataOffset));
 
         /* parse returned result into more usable form */
@@ -4344,12 +4345,12 @@ oldQFSInfoRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 18))
+                if (rc || get_bcc(&pSMBr->hdr) < 18)
                         rc = -EIO;      /* bad smb */
                 else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
                         cFYI(1, "qfsinf resp BCC: %d  Offset %d",
-                                 pSMBr->ByteCount, data_offset);
+                                 get_bcc(&pSMBr->hdr), data_offset);
 
                         response_data = (FILE_SYSTEM_ALLOC_INFO *)
                                 (((char *) &pSMBr->hdr.Protocol) + data_offset);
@@ -4423,7 +4424,7 @@ QFSInfoRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 24))
+                if (rc || get_bcc(&pSMBr->hdr) < 24)
                         rc = -EIO;      /* bad smb */
                 else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -4503,7 +4504,7 @@ QFSAttributeRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 13)) {
+                if (rc || get_bcc(&pSMBr->hdr) < 13) {
                         /* BB also check if enough bytes returned */
                         rc = -EIO;      /* bad smb */
                 } else {
@@ -4574,7 +4575,8 @@ QFSDeviceRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < sizeof(FILE_SYSTEM_DEVICE_INFO)))
+                if (rc || get_bcc(&pSMBr->hdr) <
+                          sizeof(FILE_SYSTEM_DEVICE_INFO))
                         rc = -EIO;      /* bad smb */
                 else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -4643,7 +4645,7 @@ QFSUnixRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 13)) {
+                if (rc || get_bcc(&pSMBr->hdr) < 13) {
                         rc = -EIO;      /* bad smb */
                 } else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -4788,7 +4790,7 @@ QFSPosixRetry:
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 13)) {
+                if (rc || get_bcc(&pSMBr->hdr) < 13) {
                         rc = -EIO;      /* bad smb */
                 } else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
@@ -5517,7 +5519,7 @@ QAllEAsRetry:
         of these trans2 responses */
 
         rc = validate_t2((struct smb_t2_rsp *)pSMBr);
-        if (rc || (pSMBr->ByteCount < 4)) {
+        if (rc || get_bcc(&pSMBr->hdr) < 4) {
                 rc = -EIO;      /* bad smb */
                 goto QAllEAsOut;
         }