CIFS: Send RFC1001 length in a separate iov

In order to simplify further encryption support we need to separate
RFC1001 length and SMB2 header when sending a request. Put the length
field in iov[0] and the rest of the packet into following iovs.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 66bd7fa9b7a6f739f7f5fda0d0b6fe4c79192a47..d8af15f19dd8ca1f3506f43f0a326a48f28a2d0e 100644 (file)
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -75,24 +75,20 @@ int __cifs_calc_signature(struct smb_rqst *rqst,
        struct kvec *iov = rqst->rq_iov;
        int n_vec = rqst->rq_nvec;
 
-       for (i = 0; i < n_vec; i++) {
+       if (n_vec < 2 || iov[0].iov_len != 4)
+               return -EIO;
+
+       for (i = 1; i < n_vec; i++) {
                if (iov[i].iov_len == 0)
                        continue;
                if (iov[i].iov_base == NULL) {
                        cifs_dbg(VFS, "null iovec entry\n");
                        return -EIO;
                }
-               /* The first entry includes a length field (which does not get
-                  signed that occupies the first 4 bytes before the header */
-               if (i == 0) {
-                       if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
-                               break; /* nothing to sign or corrupt header */
-                       rc = crypto_shash_update(shash,
-                               iov[i].iov_base + 4, iov[i].iov_len - 4);
-               } else {
-                       rc = crypto_shash_update(shash,
-                               iov[i].iov_base, iov[i].iov_len);
-               }
+               if (i == 1 && iov[1].iov_len <= 4)
+                       break; /* nothing to sign or corrupt header */
+               rc = crypto_shash_update(shash,
+                                        iov[i].iov_base, iov[i].iov_len);
                if (rc) {
                        cifs_dbg(VFS, "%s: Could not update with payload\n",
                                 __func__);
@@ -168,6 +164,10 @@ int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
        char smb_signature[20];
        struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 
+       if (rqst->rq_iov[0].iov_len != 4 ||
+           rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+               return -EIO;
+
        if ((cifs_pdu == NULL) || (server == NULL))
                return -EINVAL;
 
@@ -209,12 +209,14 @@ int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
                  __u32 *pexpected_response_sequence_number)
 {
-       struct kvec iov;
+       struct kvec iov[2];
 
-       iov.iov_base = cifs_pdu;
-       iov.iov_len = be32_to_cpu(cifs_pdu->smb_buf_length) + 4;
+       iov[0].iov_base = cifs_pdu;
+       iov[0].iov_len = 4;
+       iov[1].iov_base = (char *)cifs_pdu + 4;
+       iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
 
-       return cifs_sign_smbv(&iov, 1, server,
+       return cifs_sign_smbv(iov, 2, server,
                              pexpected_response_sequence_number);
 }
 
@@ -227,6 +229,10 @@ int cifs_verify_signature(struct smb_rqst *rqst,
        char what_we_think_sig_should_be[20];
        struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 
+       if (rqst->rq_iov[0].iov_len != 4 ||
+           rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+               return -EIO;
+
        if (cifs_pdu == NULL || server == NULL)
                return -EINVAL;
 

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 6d5fc87ba3353328ac0de91f0d28c5b9a8ab70e0..eb0ffac73f901692dd3f4d053f2244dd4cda3a6b 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1119,7 +1119,7 @@ struct cifs_readdata {
        int (*read_into_pages)(struct TCP_Server_Info *server,
                                struct cifs_readdata *rdata,
                                unsigned int len);
-       struct kvec                     iov;
+       struct kvec                     iov[2];
        unsigned int                    pagesz;
        unsigned int                    tailsz;
        unsigned int                    credits;

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 609ce335e6ac0683a7eaf13dce2ebe3f5fe062d8..be9fa7ffe7997517e8f3f87fcce18daf1e6c3fae 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -708,9 +708,9 @@ CIFSSMBEcho(struct TCP_Server_Info *server)
 {
        ECHO_REQ *smb;
        int rc = 0;
-       struct kvec iov;
-       struct smb_rqst rqst = { .rq_iov = &iov,
-                                .rq_nvec = 1 };
+       struct kvec iov[2];
+       struct smb_rqst rqst = { .rq_iov = iov,
+                                .rq_nvec = 2 };
 
        cifs_dbg(FYI, "In echo request\n");
 
@@ -725,8 +725,11 @@ CIFSSMBEcho(struct TCP_Server_Info *server)
        put_bcc(1, &smb->hdr);
        smb->Data[0] = 'a';
        inc_rfc1001_len(smb, 3);
-       iov.iov_base = smb;
-       iov.iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4;
+
+       iov[0].iov_len = 4;
+       iov[0].iov_base = smb;
+       iov[1].iov_len = get_rfc1002_length(smb);
+       iov[1].iov_base = (char *)smb + 4;
 
        rc = cifs_call_async(server, &rqst, NULL, cifs_echo_callback,
                             server, CIFS_ASYNC_OP | CIFS_ECHO_OP);
@@ -1509,10 +1512,12 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
        }
 
        /* set up first iov for signature check */
-       rdata->iov.iov_base = buf;
-       rdata->iov.iov_len = server->total_read;
-       cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
-                rdata->iov.iov_base, rdata->iov.iov_len);
+       rdata->iov[0].iov_base = buf;
+       rdata->iov[0].iov_len = 4;
+       rdata->iov[1].iov_base = buf + 4;
+       rdata->iov[1].iov_len = server->total_read - 4;
+       cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n",
+                rdata->iov[0].iov_base, server->total_read);
 
        /* how much data is in the response? */
        data_len = server->ops->read_data_length(buf);
@@ -1545,8 +1550,8 @@ cifs_readv_callback(struct mid_q_entry *mid)
        struct cifs_readdata *rdata = mid->callback_data;
        struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink);
        struct TCP_Server_Info *server = tcon->ses->server;
-       struct smb_rqst rqst = { .rq_iov = &rdata->iov,
-                                .rq_nvec = 1,
+       struct smb_rqst rqst = { .rq_iov = rdata->iov,
+                                .rq_nvec = 2,
                                 .rq_pages = rdata->pages,
                                 .rq_npages = rdata->nr_pages,
                                 .rq_pagesz = rdata->pagesz,
@@ -1601,8 +1606,8 @@ cifs_async_readv(struct cifs_readdata *rdata)
        READ_REQ *smb = NULL;
        int wct;
        struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink);
-       struct smb_rqst rqst = { .rq_iov = &rdata->iov,
-                                .rq_nvec = 1 };
+       struct smb_rqst rqst = { .rq_iov = rdata->iov,
+                                .rq_nvec = 2 };
 
        cifs_dbg(FYI, "%s: offset=%llu bytes=%u\n",
                 __func__, rdata->offset, rdata->bytes);
@@ -1642,8 +1647,10 @@ cifs_async_readv(struct cifs_readdata *rdata)
        }
 
        /* 4 for RFC1001 length + 1 for BCC */
-       rdata->iov.iov_base = smb;
-       rdata->iov.iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4;
+       rdata->iov[0].iov_base = smb;
+       rdata->iov[0].iov_len = 4;
+       rdata->iov[1].iov_base = (char *)smb + 4;
+       rdata->iov[1].iov_len = get_rfc1002_length(smb);
 
        kref_get(&rdata->refcount);
        rc = cifs_call_async(tcon->ses->server, &rqst, cifs_readv_receive,
@@ -2096,7 +2103,7 @@ cifs_async_writev(struct cifs_writedata *wdata,
        WRITE_REQ *smb = NULL;
        int wct;
        struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
-       struct kvec iov;
+       struct kvec iov[2];
        struct smb_rqst rqst = { };
 
        if (tcon->ses->capabilities & CAP_LARGE_FILES) {
@@ -2129,11 +2136,13 @@ cifs_async_writev(struct cifs_writedata *wdata,
            cpu_to_le16(offsetof(struct smb_com_write_req, Data) - 4);
 
        /* 4 for RFC1001 length + 1 for BCC */
-       iov.iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4 + 1;
-       iov.iov_base = smb;
+       iov[0].iov_len = 4;
+       iov[0].iov_base = smb;
+       iov[1].iov_len = get_rfc1002_length(smb) + 1;
+       iov[1].iov_base = (char *)smb + 4;
 
-       rqst.rq_iov = &iov;
-       rqst.rq_nvec = 1;
+       rqst.rq_iov = iov;
+       rqst.rq_nvec = 2;
        rqst.rq_pages = wdata->pages;
        rqst.rq_npages = wdata->nr_pages;
        rqst.rq_pagesz = wdata->pagesz;
@@ -2154,7 +2163,7 @@ cifs_async_writev(struct cifs_writedata *wdata,
                                (struct smb_com_writex_req *)smb;
                inc_rfc1001_len(&smbw->hdr, wdata->bytes + 5);
                put_bcc(wdata->bytes + 5, &smbw->hdr);
-               iov.iov_len += 4; /* pad bigger by four bytes */
+               iov[1].iov_len += 4; /* pad bigger by four bytes */
        }
 
        kref_get(&wdata->refcount);

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index fb6cf1b68dc530b1a9656139e35e4b6cca058ba0..438c4b108c07471e1c9bfc871eab10a20438a6c8 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2047,9 +2047,9 @@ SMB2_echo(struct TCP_Server_Info *server)
 {
        struct smb2_echo_req *req;
        int rc = 0;
-       struct kvec iov;
-       struct smb_rqst rqst = { .rq_iov = &iov,
-                                .rq_nvec = 1 };
+       struct kvec iov[2];
+       struct smb_rqst rqst = { .rq_iov = iov,
+                                .rq_nvec = 2 };
 
        cifs_dbg(FYI, "In echo request\n");
 
@@ -2065,9 +2065,11 @@ SMB2_echo(struct TCP_Server_Info *server)
 
        req->hdr.sync_hdr.CreditRequest = cpu_to_le16(1);
 
-       iov.iov_base = (char *)req;
        /* 4 for rfc1002 length field */
-       iov.iov_len = get_rfc1002_length(req) + 4;
+       iov[0].iov_len = 4;
+       iov[0].iov_base = (char *)req;
+       iov[1].iov_len = get_rfc1002_length(req);
+       iov[1].iov_base = (char *)req + 4;
 
        rc = cifs_call_async(server, &rqst, NULL, smb2_echo_callback, server,
                             CIFS_ECHO_OP);
@@ -2123,8 +2125,9 @@ SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
  * have the end_of_chain boolean set to true.
  */
 static int
-smb2_new_read_req(struct kvec *iov, struct cifs_io_parms *io_parms,
-                 unsigned int remaining_bytes, int request_type)
+smb2_new_read_req(void **buf, unsigned int *total_len,
+                 struct cifs_io_parms *io_parms, unsigned int remaining_bytes,
+                 int request_type)
 {
        int rc = -EACCES;
        struct smb2_read_req *req = NULL;
@@ -2172,9 +2175,9 @@ smb2_new_read_req(struct kvec *iov, struct cifs_io_parms *io_parms,
        else
                req->RemainingBytes = 0;
 
-       iov[0].iov_base = (char *)req;
+       *buf = req;
        /* 4 for rfc1002 length field */
-       iov[0].iov_len = get_rfc1002_length(req) + 4;
+       *total_len = get_rfc1002_length(req) + 4;
        return rc;
 }
 
@@ -2184,10 +2187,11 @@ smb2_readv_callback(struct mid_q_entry *mid)
        struct cifs_readdata *rdata = mid->callback_data;
        struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink);
        struct TCP_Server_Info *server = tcon->ses->server;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(rdata->iov.iov_base);
+       struct smb2_sync_hdr *shdr =
+                               (struct smb2_sync_hdr *)rdata->iov[1].iov_base;
        unsigned int credits_received = 1;
-       struct smb_rqst rqst = { .rq_iov = &rdata->iov,
-                                .rq_nvec = 1,
+       struct smb_rqst rqst = { .rq_iov = rdata->iov,
+                                .rq_nvec = 2,
                                 .rq_pages = rdata->pages,
                                 .rq_npages = rdata->nr_pages,
                                 .rq_pagesz = rdata->pagesz,
@@ -2238,7 +2242,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
        add_credits(server, credits_received, 0);
 }
 
-/* smb2_async_readv - send an async write, and set up mid to handle result */
+/* smb2_async_readv - send an async read, and set up mid to handle result */
 int
 smb2_async_readv(struct cifs_readdata *rdata)
 {
@@ -2246,9 +2250,10 @@ smb2_async_readv(struct cifs_readdata *rdata)
        char *buf;
        struct smb2_sync_hdr *shdr;
        struct cifs_io_parms io_parms;
-       struct smb_rqst rqst = { .rq_iov = &rdata->iov,
-                                .rq_nvec = 1 };
+       struct smb_rqst rqst = { .rq_iov = rdata->iov,
+                                .rq_nvec = 2 };
        struct TCP_Server_Info *server;
+       unsigned int total_len;
 
        cifs_dbg(FYI, "%s: offset=%llu bytes=%u\n",
                 __func__, rdata->offset, rdata->bytes);
@@ -2262,7 +2267,7 @@ smb2_async_readv(struct cifs_readdata *rdata)
 
        server = io_parms.tcon->ses->server;
 
-       rc = smb2_new_read_req(&rdata->iov, &io_parms, 0, 0);
+       rc = smb2_new_read_req((void **) &buf, &total_len, &io_parms, 0, 0);
        if (rc) {
                if (rc == -EAGAIN && rdata->credits) {
                        /* credits was reset by reconnect */
@@ -2275,10 +2280,12 @@ smb2_async_readv(struct cifs_readdata *rdata)
                return rc;
        }
 
-       buf = rdata->iov.iov_base;
        shdr = get_sync_hdr(buf);
        /* 4 for rfc1002 length field */
-       rdata->iov.iov_len = get_rfc1002_length(rdata->iov.iov_base) + 4;
+       rdata->iov[0].iov_len = 4;
+       rdata->iov[0].iov_base = buf;
+       rdata->iov[1].iov_len = total_len - 4;
+       rdata->iov[1].iov_base = buf + 4;
 
        if (rdata->credits) {
                shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
@@ -2314,12 +2321,17 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
        struct smb2_sync_hdr *shdr;
        struct kvec iov[1];
        struct kvec rsp_iov;
+       unsigned int total_len;
+       char *req;
 
        *nbytes = 0;
-       rc = smb2_new_read_req(iov, io_parms, 0, 0);
+       rc = smb2_new_read_req((void **)&req, &total_len, io_parms, 0, 0);
        if (rc)
                return rc;
 
+       iov[0].iov_base = buf;
+       iov[0].iov_len = total_len;
+
        rc = SendReceive2(xid, io_parms->tcon->ses, iov, 1,
                          &resp_buftype, CIFS_LOG_ERROR, &rsp_iov);
        cifs_small_buf_release(iov[0].iov_base);
@@ -2424,8 +2436,8 @@ smb2_async_writev(struct cifs_writedata *wdata,
        struct smb2_sync_hdr *shdr;
        struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
        struct TCP_Server_Info *server = tcon->ses->server;
-       struct kvec iov;
-       struct smb_rqst rqst;
+       struct kvec iov[2];
+       struct smb_rqst rqst = { };
 
        rc = small_smb2_init(SMB2_WRITE, tcon, (void **) &req);
        if (rc) {
@@ -2455,11 +2467,13 @@ smb2_async_writev(struct cifs_writedata *wdata,
        req->RemainingBytes = 0;
 
        /* 4 for rfc1002 length field and 1 for Buffer */
-       iov.iov_len = get_rfc1002_length(req) + 4 - 1;
-       iov.iov_base = req;
+       iov[0].iov_len = 4;
+       iov[0].iov_base = req;
+       iov[1].iov_len = get_rfc1002_length(req) - 1;
+       iov[1].iov_base = (char *)req + 4;
 
-       rqst.rq_iov = &iov;
-       rqst.rq_nvec = 1;
+       rqst.rq_iov = iov;
+       rqst.rq_nvec = 2;
        rqst.rq_pages = wdata->pages;
        rqst.rq_npages = wdata->nr_pages;
        rqst.rq_pagesz = wdata->pagesz;

diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 52ff937fd1ed41a5799f4d2983cc962568da5a2d..93b27752b634a41002794b75d4e573ad295ac152 100644 (file)
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -138,7 +138,7 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
        unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
        unsigned char *sigptr = smb2_signature;
        struct kvec *iov = rqst->rq_iov;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(iov[0].iov_base);
+       struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
        struct cifs_ses *ses;
 
        ses = smb2_find_smb_ses(shdr, server);
@@ -355,7 +355,7 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
        unsigned char smb3_signature[SMB2_CMACAES_SIZE];
        unsigned char *sigptr = smb3_signature;
        struct kvec *iov = rqst->rq_iov;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(iov[0].iov_base);
+       struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
        struct cifs_ses *ses;
 
        ses = smb2_find_smb_ses(shdr, server);
@@ -400,7 +400,8 @@ static int
 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
        int rc = 0;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(rqst->rq_iov[0].iov_base);
+       struct smb2_sync_hdr *shdr =
+                       (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
 
        if (!(shdr->Flags & SMB2_FLAGS_SIGNED) ||
            server->tcpStatus == CifsNeedNegotiate)
@@ -421,7 +422,8 @@ smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
        unsigned int rc;
        char server_response_sig[16];
-       struct smb2_sync_hdr *shdr = get_sync_hdr(rqst->rq_iov[0].iov_base);
+       struct smb2_sync_hdr *shdr =
+                       (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
 
        if ((shdr->Command == SMB2_NEGOTIATE) ||
            (shdr->Command == SMB2_SESSION_SETUP) ||
@@ -550,12 +552,14 @@ smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
                   bool log_error)
 {
        unsigned int len = get_rfc1002_length(mid->resp_buf);
-       struct kvec iov;
-       struct smb_rqst rqst = { .rq_iov = &iov,
-                                .rq_nvec = 1 };
+       struct kvec iov[2];
+       struct smb_rqst rqst = { .rq_iov = iov,
+                                .rq_nvec = 2 };
 
-       iov.iov_base = (char *)mid->resp_buf;
-       iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4;
+       iov[0].iov_base = (char *)mid->resp_buf;
+       iov[0].iov_len = 4;
+       iov[1].iov_base = (char *)mid->resp_buf + 4;
+       iov[1].iov_len = len;
 
        dump_smb(mid->resp_buf, min_t(u32, 80, len));
        /* convert the length into a more usable form */
@@ -575,7 +579,8 @@ struct mid_q_entry *
 smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 {
        int rc;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(rqst->rq_iov[0].iov_base);
+       struct smb2_sync_hdr *shdr =
+                       (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
        struct mid_q_entry *mid;
 
        smb2_seq_num_into_buf(ses->server, shdr);
@@ -595,7 +600,8 @@ struct mid_q_entry *
 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 {
        int rc;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(rqst->rq_iov[0].iov_base);
+       struct smb2_sync_hdr *shdr =
+                       (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
        struct mid_q_entry *mid;
 
        smb2_seq_num_into_buf(server, shdr);

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 878f0dceeb131d8617baaf6054cc2769c11ee73d..dacfdf080330461b8a14b1898642e7c4cc08e349 100644 (file)
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -245,8 +245,12 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
                return -EIO;
        }
 
+       if (n_vec < 2)
+               return -EIO;
+
        cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
        dump_smb(iov[0].iov_base, iov[0].iov_len);
+       dump_smb(iov[1].iov_base, iov[1].iov_len);
 
        /* cork the socket */
        kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
@@ -321,12 +325,14 @@ int
 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
         unsigned int smb_buf_length)
 {
-       struct kvec iov;
+       struct kvec iov[2];
 
-       iov.iov_base = smb_buffer;
-       iov.iov_len = smb_buf_length + 4;
+       iov[0].iov_base = smb_buffer;
+       iov[0].iov_len = 4;
+       iov[1].iov_base = (char *)smb_buffer + 4;
+       iov[1].iov_len = smb_buf_length;
 
-       return smb_sendv(server, &iov, 1);
+       return smb_sendv(server, iov, 2);
 }
 
 static int
@@ -454,6 +460,10 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
        struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
        struct mid_q_entry *mid;
 
+       if (rqst->rq_iov[0].iov_len != 4 ||
+           rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+               return ERR_PTR(-EIO);
+
        /* enable signing if server requires it */
        if (server->sign)
                hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
@@ -477,8 +487,8 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
  */
 int
 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
-               mid_receive_t *receive, mid_callback_t *callback,
-               void *cbdata, const int flags)
+               mid_receive_t *receive, mid_callback_t *callback, void *cbdata,
+               const int flags)
 {
        int rc, timeout, optype;
        struct mid_q_entry *mid;
@@ -613,13 +623,15 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 
        /* convert the length into a more usable form */
        if (server->sign) {
-               struct kvec iov;
+               struct kvec iov[2];
                int rc = 0;
-               struct smb_rqst rqst = { .rq_iov = &iov,
-                                        .rq_nvec = 1 };
+               struct smb_rqst rqst = { .rq_iov = iov,
+                                        .rq_nvec = 2 };
 
-               iov.iov_base = mid->resp_buf;
-               iov.iov_len = len;
+               iov[0].iov_base = mid->resp_buf;
+               iov[0].iov_len = 4;
+               iov[1].iov_base = (char *)mid->resp_buf + 4;
+               iov[1].iov_len = len - 4;
                /* FIXME: add code to kill session */
                rc = cifs_verify_signature(&rqst, server,
                                           mid->sequence_number);
@@ -639,6 +651,10 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
        struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
        struct mid_q_entry *mid;
 
+       if (rqst->rq_iov[0].iov_len != 4 ||
+           rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+               return ERR_PTR(-EIO);
+
        rc = allocate_mid(ses, hdr, &mid);
        if (rc)
                return ERR_PTR(rc);
@@ -650,18 +666,16 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
        return mid;
 }
 
-int
-SendReceive2(const unsigned int xid, struct cifs_ses *ses,
-            struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
-            const int flags, struct kvec *resp_iov)
+static int
+cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
+              struct smb_rqst *rqst, int *resp_buf_type, const int flags,
+              struct kvec *resp_iov)
 {
        int rc = 0;
        int timeout, optype;
        struct mid_q_entry *midQ;
-       char *buf = iov[0].iov_base;
        unsigned int credits = 1;
-       struct smb_rqst rqst = { .rq_iov = iov,
-                                .rq_nvec = n_vec };
+       char *buf;
 
        timeout = flags & CIFS_TIMEOUT_MASK;
        optype = flags & CIFS_OP_MASK;
@@ -694,7 +708,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 
        mutex_lock(&ses->server->srv_mutex);
 
-       midQ = ses->server->ops->setup_request(ses, &rqst);
+       midQ = ses->server->ops->setup_request(ses, rqst);
        if (IS_ERR(midQ)) {
                mutex_unlock(&ses->server->srv_mutex);
                /* Update # of requests on wire to server */
@@ -704,7 +718,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 
        midQ->mid_state = MID_REQUEST_SUBMITTED;
        cifs_in_send_inc(ses->server);
-       rc = smb_sendv(ses->server, iov, n_vec);
+       rc = smb_send_rqst(ses->server, rqst);
        cifs_in_send_dec(ses->server);
        cifs_save_when_sent(midQ);
 
@@ -720,7 +734,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 
        rc = wait_for_response(ses->server, midQ);
        if (rc != 0) {
-               send_cancel(ses->server, &rqst, midQ);
+               send_cancel(ses->server, rqst, midQ);
                spin_lock(&GlobalMid_Lock);
                if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
                        midQ->callback = DeleteMidQEntry;
@@ -766,6 +780,36 @@ out:
        return rc;
 }
 
+int
+SendReceive2(const unsigned int xid, struct cifs_ses *ses,
+            struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
+            const int flags, struct kvec *resp_iov)
+{
+       struct smb_rqst rqst;
+       struct kvec *new_iov;
+       int rc;
+
+       new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1), GFP_KERNEL);
+       if (!new_iov)
+               return -ENOMEM;
+
+       /* 1st iov is a RFC1001 length followed by the rest of the packet */
+       memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
+
+       new_iov[0].iov_base = new_iov[1].iov_base;
+       new_iov[0].iov_len = 4;
+       new_iov[1].iov_base += 4;
+       new_iov[1].iov_len -= 4;
+
+       memset(&rqst, 0, sizeof(struct smb_rqst));
+       rqst.rq_iov = new_iov;
+       rqst.rq_nvec = n_vec + 1;
+
+       rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
+       kfree(new_iov);
+       return rc;
+}
+
 int
 SendReceive(const unsigned int xid, struct cifs_ses *ses,
            struct smb_hdr *in_buf, struct smb_hdr *out_buf,