s3:smbd: allow "server min protocol = SMB3_00" to go via "SMB 2.???" negprot

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12540

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/source3/smbd/negprot.c b/source3/smbd/negprot.c
index bd09b1df1b1d582db8374545e151e238fa0fae06..cdde334ccba62cae9f84a50565344c5b5d0e2d86 100644 (file)
--- a/source3/smbd/negprot.c
+++ b/source3/smbd/negprot.c
@@ -544,6 +544,8 @@ void reply_negprot(struct smb_request *req)
        struct smbXsrv_connection *xconn = req->xconn;
        struct smbd_server_connection *sconn = req->sconn;
        bool signing_required = true;
+       int max_proto;
+       int min_proto;
 
        START_PROFILE(SMBnegprot);
 
@@ -688,11 +690,28 @@ void reply_negprot(struct smb_request *req)
                          FLAG_MSG_GENERAL|FLAG_MSG_SMBD
                          |FLAG_MSG_PRINT_GENERAL);
 
+       /*
+        * Anything higher than PROTOCOL_SMB2_10 still
+        * needs to go via "SMB 2.???", which is marked
+        * as PROTOCOL_SMB2_10.
+        *
+        * The real negotiation happens via reply_smb20ff()
+        * using SMB2 Negotiation.
+        */
+       max_proto = lp_server_max_protocol();
+       if (max_proto > PROTOCOL_SMB2_10) {
+               max_proto = PROTOCOL_SMB2_10;
+       }
+       min_proto = lp_server_min_protocol();
+       if (min_proto > PROTOCOL_SMB2_10) {
+               min_proto = PROTOCOL_SMB2_10;
+       }
+
        /* Check for protocols, most desirable first */
        for (protocol = 0; supported_protocols[protocol].proto_name; protocol++) {
                i = 0;
-               if ((supported_protocols[protocol].protocol_level <= lp_server_max_protocol()) &&
-                               (supported_protocols[protocol].protocol_level >= lp_server_min_protocol()))
+               if ((supported_protocols[protocol].protocol_level <= max_proto) &&
+                   (supported_protocols[protocol].protocol_level >= min_proto))
                        while (i < num_cliprotos) {
                                if (strequal(cliprotos[i],supported_protocols[protocol].proto_name)) {
                                        choice = i;