net/smc: Remove validation of reserved bits in CLC Decline message

JIRA: https://issues.redhat.com/browse/RHEL-124197

commit cc282f7
Author: Mahanta Jambigi <mjambigi@linux.ibm.com>
Date:   Tue Sep 2 10:20:41 2025 +0200

    net/smc: Remove validation of reserved bits in CLC Decline message

    Currently SMC code is validating the reserved bits while parsing the incoming
    CLC decline message & when this validation fails, its treated as a protocol
    error. As a result, the SMC connection is terminated instead of falling back to
    TCP. As per RFC7609[1] specs we shouldn't be validating the reserved bits that
    is part of CLC message. This patch fixes this issue.

    CLC Decline message format can viewed here[2].

    [1] https://datatracker.ietf.org/doc/html/rfc7609#page-92
    [2] https://datatracker.ietf.org/doc/html/rfc7609#page-105

    Fixes: 8ade200 ("net/smc: add v2 format of CLC decline message")
    Signed-off-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
    Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
    Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
    Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
    Link: https://patch.msgid.link/20250902082041.98996-1-mjambigi@linux.ibm.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Hidayath Khan <hidayath@linux.ibm.com>
Signed-off-by: Mete Durlu <mdurlu@redhat.com>

Author: Mete Durlu

net/smc/smc_clc.c

@@ -426,8 +426,6 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 {
 	struct smc_clc_msg_hdr *hdr = &dclc->hdr;
 
-	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
-		return false;
 	if (hdr->version == SMC_V1) {
 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
 			return false;