[SCSI] iscsi_tcp: fix partial digest recv

When a digest is spread across two network buffers, we currently
ignore this and try to check the digest with the partial buffer.
Or course this fails. This patch has use iscsi_tcp_copy to
copy the whole digest before testing it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 5d292d0b65ec..d91e8949c71e 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -648,10 +648,9 @@ iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
  *      byte counters.
  **/
 static inline int
-iscsi_tcp_copy(struct iscsi_conn *conn)
+iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
 {
         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
-        int buf_size = tcp_conn->in.datalen;
         int buf_left = buf_size - tcp_conn->data_copied;
         int size = min(tcp_conn->in.copy, buf_left);
         int rc;
@@ -812,7 +811,7 @@ iscsi_data_recv(struct iscsi_conn *conn)
                  * Collect data segment to the connection's data
                  * placeholder
                  */
-                if (iscsi_tcp_copy(conn)) {
+                if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
                         rc = -EAGAIN;
                         goto exit;
                 }
@@ -899,10 +898,15 @@ more:
 
                 debug_tcp("extra data_recv offset %d copy %d\n",
                           tcp_conn->in.offset, tcp_conn->in.copy);
-                skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
-                                &recv_digest, 4);
-                tcp_conn->in.offset += 4;
-                tcp_conn->in.copy -= 4;
+                rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
+                if (rc) {
+                        if (rc == -EAGAIN)
+                                goto again;
+                        iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+                        return 0;
+                }
+
+                memcpy(&recv_digest, conn->data, sizeof(uint32_t));
                 if (recv_digest != tcp_conn->in.datadgst) {
                         debug_tcp("iscsi_tcp: data digest error!"
                                   "0x%x != 0x%x\n", recv_digest,
@@ -942,9 +946,10 @@ more:
                                                      &sg, 1);
                         }
                         crypto_digest_final(tcp_conn->rx_tfm,
-                                            (u8 *) & tcp_conn->in.datadgst);
+                                            (u8 *) &tcp_conn->in.datadgst);
                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
+                        tcp_conn->data_copied = 0;
                 } else
                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
         }