s3:smb2_server: max_trans, max_read and max_write are limited to 64 kilobytes

Only if SMB2_CAP_LARGE_MTU is supported we should announce larger limits.

metze
(cherry picked from commit e603929b9801ad6cc47dead19d27b42fe46489c7)

diff --git a/source3/smbd/smb2_negprot.c b/source3/smbd/smb2_negprot.c
index 9245d6d79793f44d6e0d14ceb58f9dbc3fcf78d8..414f59054046df2259274ebd890b09a5dad3a382 100644 (file)
--- a/source3/smbd/smb2_negprot.c
+++ b/source3/smbd/smb2_negprot.c
@@ -76,6 +76,10 @@ NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
        uint16_t dialect_count;
        uint16_t dialect = 0;
        uint32_t capabilities;
+       uint32_t max_limit;
+       uint32_t max_trans = lp_smb2_max_trans();
+       uint32_t max_read = lp_smb2_max_read();
+       uint32_t max_write = lp_smb2_max_write();
 
 /* TODO: drop the connection with INVALID_PARAMETER */
 
@@ -133,6 +137,16 @@ NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
                capabilities |= SMB2_CAP_DFS;
        }
 
+       /*
+        * Unless we implement SMB2_CAP_LARGE_MTU,
+        * 0x10000 (65536) is the maximum allowed message size
+        */
+       max_limit = 0x10000;
+
+       max_trans = MIN(max_limit, max_trans);
+       max_read  = MIN(max_limit, max_read);
+       max_write = MIN(max_limit, max_write);
+
        security_offset = SMB2_HDR_BODY + 0x40;
 
 #if 1
@@ -158,9 +172,9 @@ NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
               negprot_spnego_blob.data, 16);   /* server guid */
        SIVAL(outbody.data, 0x18,
              capabilities);                    /* capabilities */
-       SIVAL(outbody.data, 0x1C, lp_smb2_max_trans()); /* max transact size */
-       SIVAL(outbody.data, 0x20, lp_smb2_max_read());  /* max read size */
-       SIVAL(outbody.data, 0x24, lp_smb2_max_write()); /* max write size */
+       SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
+       SIVAL(outbody.data, 0x20, max_trans);   /* max read size */
+       SIVAL(outbody.data, 0x24, max_trans);   /* max write size */
        SBVAL(outbody.data, 0x28, 0);           /* system time */
        SBVAL(outbody.data, 0x30, 0);           /* server start time */
        SSVAL(outbody.data, 0x38,