cifs: remove rfc1002 header from all SMB2 response structures

Separate out all the 4 byte rfc1002 headers so that they are no longer
part of the SMB2 header structures to prepare for future work to add
compounding support.

Update the smb3 transform header processing that we no longer have
a rfc1002 header at the start of this structure.

Update smb2_readv_callback to accommodate that the first iovector in the
response is no the smb2 header and no longer a rfc1002 header.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 65 insertions, 47 deletions

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 7c0edd2ab784..20cc67c3a6d0 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2144,12 +2144,11 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile)
 }
 
 static void
-fill_transform_hdr(struct TCP_Server_Info *server,
-		   struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq)
+fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
+		   struct smb_rqst *old_rq)
 {
 	struct smb2_sync_hdr *shdr =
 			(struct smb2_sync_hdr *)old_rq->rq_iov[1].iov_base;
-	unsigned int orig_len = get_rfc1002_length(old_rq->rq_iov[0].iov_base);
 
 	memset(tr_hdr, 0, sizeof(struct smb2_transform_hdr));
 	tr_hdr->ProtocolId = SMB2_TRANSFORM_PROTO_NUM;
@@ -2157,8 +2156,6 @@ fill_transform_hdr(struct TCP_Server_Info *server,
 	tr_hdr->Flags = cpu_to_le16(0x01);
 	get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CMM_NONCE);
 	memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8);
-	inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - server->vals->header_preamble_size);
-	inc_rfc1001_len(tr_hdr, orig_len);
 }
 
 /* We can not use the normal sg_set_buf() as we will sometimes pass a
@@ -2170,11 +2167,16 @@ static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
 	sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
 }
 
+/* Assumes:
+ * rqst->rq_iov[0]  is rfc1002 length
+ * rqst->rq_iov[1]  is tranform header
+ * rqst->rq_iov[2+] data to be encrypted/decrypted
+ */
 static struct scatterlist *
 init_sg(struct smb_rqst *rqst, u8 *sign)
 {
-	unsigned int sg_len = rqst->rq_nvec + rqst->rq_npages + 1;
-	unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24;
+	unsigned int sg_len = rqst->rq_nvec + rqst->rq_npages;
+	unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 20;
 	struct scatterlist *sg;
 	unsigned int i;
 	unsigned int j;
@@ -2184,10 +2186,10 @@ init_sg(struct smb_rqst *rqst, u8 *sign)
 		return NULL;
 
 	sg_init_table(sg, sg_len);
-	smb2_sg_set_buf(&sg[0], rqst->rq_iov[0].iov_base + 24, assoc_data_len);
-	for (i = 1; i < rqst->rq_nvec; i++)
-		smb2_sg_set_buf(&sg[i], rqst->rq_iov[i].iov_base,
-						rqst->rq_iov[i].iov_len);
+	smb2_sg_set_buf(&sg[0], rqst->rq_iov[1].iov_base + 20, assoc_data_len);
+	for (i = 1; i < rqst->rq_nvec - 1; i++)
+		smb2_sg_set_buf(&sg[i], rqst->rq_iov[i+1].iov_base,
+						rqst->rq_iov[i+1].iov_len);
 	for (j = 0; i < sg_len - 1; i++, j++) {
 		unsigned int len = (j < rqst->rq_npages - 1) ? rqst->rq_pagesz
 							: rqst->rq_tailsz;
@@ -2219,9 +2221,10 @@ smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key)
 }
 /*
  * Encrypt or decrypt @rqst message. @rqst has the following format:
- * iov[0] - transform header (associate data),
- * iov[1-N] and pages - data to encrypt.
- * On success return encrypted data in iov[1-N] and pages, leave iov[0]
+ * iov[0] - rfc1002 length
+ * iov[1] - transform header (associate data),
+ * iov[2-N] and pages - data to encrypt.
+ * On success return encrypted data in iov[2-N] and pages, leave iov[0-1]
  * untouched.
  */
 static int
@@ -2316,6 +2319,10 @@ free_req:
 	return rc;
 }
 
+/*
+ * This is called from smb_send_rqst. At this point we have the rfc1002
+ * header as the first element in the vector.
+ */
 static int
 smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
 		       struct smb_rqst *old_rq)
@@ -2324,6 +2331,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
 	struct page **pages;
 	struct smb2_transform_hdr *tr_hdr;
 	unsigned int npages = old_rq->rq_npages;
+	unsigned int orig_len = get_rfc1002_length(old_rq->rq_iov[0].iov_base);
 	int i;
 	int rc = -ENOMEM;
 
@@ -2342,24 +2350,34 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
 			goto err_free_pages;
 	}
 
-	iov = kmalloc_array(old_rq->rq_nvec, sizeof(struct kvec), GFP_KERNEL);
+	/* Make space for one extra iov to hold the transform header */
+	iov = kmalloc_array(old_rq->rq_nvec + 1, sizeof(struct kvec),
+			    GFP_KERNEL);
 	if (!iov)
 		goto err_free_pages;
 
 	/* copy all iovs from the old except the 1st one (rfc1002 length) */
-	memcpy(&iov[1], &old_rq->rq_iov[1],
+	memcpy(&iov[2], &old_rq->rq_iov[1],
 				sizeof(struct kvec) * (old_rq->rq_nvec - 1));
+	/* copy the rfc1002 iov */
+	iov[0].iov_base = old_rq->rq_iov[0].iov_base;
+	iov[0].iov_len  = old_rq->rq_iov[0].iov_len;
+
 	new_rq->rq_iov = iov;
-	new_rq->rq_nvec = old_rq->rq_nvec;
+	new_rq->rq_nvec = old_rq->rq_nvec + 1;
 
 	tr_hdr = kmalloc(sizeof(struct smb2_transform_hdr), GFP_KERNEL);
 	if (!tr_hdr)
 		goto err_free_iov;
 
-	/* fill the 1st iov with a transform header */
-	fill_transform_hdr(server, tr_hdr, old_rq);
-	new_rq->rq_iov[0].iov_base = tr_hdr;
-	new_rq->rq_iov[0].iov_len = sizeof(struct smb2_transform_hdr);
+	/* fill the 2nd iov with a transform header */
+	fill_transform_hdr(tr_hdr, orig_len, old_rq);
+	new_rq->rq_iov[1].iov_base = tr_hdr;
+	new_rq->rq_iov[1].iov_len = sizeof(struct smb2_transform_hdr);
+
+	/* Update rfc1002 header */
+	inc_rfc1001_len(new_rq->rq_iov[0].iov_base,
+			sizeof(struct smb2_transform_hdr));
 
 	/* copy pages form the old */
 	for (i = 0; i < npages; i++) {
@@ -2399,7 +2417,7 @@ smb3_free_transform_rq(struct smb_rqst *rqst)
 		put_page(rqst->rq_pages[i]);
 	kfree(rqst->rq_pages);
 	/* free transform header */
-	kfree(rqst->rq_iov[0].iov_base);
+	kfree(rqst->rq_iov[1].iov_base);
 	kfree(rqst->rq_iov);
 }
 
@@ -2416,18 +2434,19 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
 		 unsigned int buf_data_size, struct page **pages,
 		 unsigned int npages, unsigned int page_data_size)
 {
-	struct kvec iov[2];
+	struct kvec iov[3];
 	struct smb_rqst rqst = {NULL};
-	struct smb2_hdr *hdr;
 	int rc;
 
-	iov[0].iov_base = buf;
-	iov[0].iov_len = sizeof(struct smb2_transform_hdr);
-	iov[1].iov_base = buf + sizeof(struct smb2_transform_hdr);
-	iov[1].iov_len = buf_data_size;
+	iov[0].iov_base = NULL;
+	iov[0].iov_len = 0;
+	iov[1].iov_base = buf;
+	iov[1].iov_len = sizeof(struct smb2_transform_hdr);
+	iov[2].iov_base = buf + sizeof(struct smb2_transform_hdr);
+	iov[2].iov_len = buf_data_size;
 
 	rqst.rq_iov = iov;
-	rqst.rq_nvec = 2;
+	rqst.rq_nvec = 3;
 	rqst.rq_pages = pages;
 	rqst.rq_npages = npages;
 	rqst.rq_pagesz = PAGE_SIZE;
@@ -2439,10 +2458,9 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
 	if (rc)
 		return rc;
 
-	memmove(buf + server->vals->header_preamble_size, iov[1].iov_base, buf_data_size);
-	hdr = (struct smb2_hdr *)buf;
-	hdr->smb2_buf_length = cpu_to_be32(buf_data_size + page_data_size);
-	server->total_read = buf_data_size + page_data_size + server->vals->header_preamble_size;
+	memmove(buf + server->vals->header_preamble_size, iov[2].iov_base, buf_data_size);
+
+	server->total_read = buf_data_size + page_data_size;
 
 	return rc;
 }
@@ -3196,8 +3214,8 @@ struct smb_version_values smb20_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3217,8 +3235,8 @@ struct smb_version_values smb21_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3238,8 +3256,8 @@ struct smb_version_values smb3any_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3259,8 +3277,8 @@ struct smb_version_values smbdefault_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3280,8 +3298,8 @@ struct smb_version_values smb30_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3301,8 +3319,8 @@ struct smb_version_values smb302_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,
@@ -3323,8 +3341,8 @@ struct smb_version_values smb311_values = {
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
 	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
-	.header_size = sizeof(struct smb2_hdr),
-	.header_preamble_size = 4,
+	.header_size = sizeof(struct smb2_sync_hdr),
+	.header_preamble_size = 0,
 	.max_header_size = MAX_SMB2_HDR_SIZE,
 	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
 	.lock_cmd = SMB2_LOCK,