[SCSI] libfcoe: add checking disable flag in FIP_FKA_ADV

When the D bit is set if the FKA_ADV_Period of the FIP Discovery
Advertisement, the ENode should not transmit period ENode FIP Keep Alive and
VN_Port FIP Keep Alive (FC-BB-5 Rev2, 7.8.3.13).

Note that fcf->flags is taken directly from the fip_header, I am claiming one
bit for the purpose of the FIP_FKA_Period D bit as FIP_FL_FK_ADV_B, and use
FIP_HEADER_FLAGS as bitmask for bits used in fip_header.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/fcoe/libfcoe.c

@@ -665,6 +665,8 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
 			if (dlen != sizeof(struct fip_fka_desc))
 				goto len_err;
 			fka = (struct fip_fka_desc *)desc;
+			if (fka->fd_flags & FIP_FKA_ADV_D)
+				fcf->fd_flags = 1;
 			t = ntohl(fka->fd_fka_period);
 			if (t >= FCOE_CTLR_MIN_FKA)
 				fcf->fka_period = msecs_to_jiffies(t);
@@ -1160,7 +1162,7 @@ static void fcoe_ctlr_timeout(unsigned long arg)
 		}
 	}
 
-	if (sel) {
+	if (sel && !sel->fd_flags) {
 		if (time_after_eq(jiffies, fip->ctlr_ka_time)) {
 			fip->ctlr_ka_time = jiffies + sel->fka_period;
 			fip->send_ctlr_ka = 1;

include/scsi/fc/fc_fip.h

@@ -214,10 +214,20 @@ struct fip_vn_desc {
  */
 struct fip_fka_desc {
 	struct fip_desc fd_desc;
-	__u8		fd_resvd[2];
+	__u8		fd_resvd;
+	__u8		fd_flags;	/* bit0 is fka disable flag */
 	__be32		fd_fka_period;	/* adv./keep-alive period in mS */
 } __attribute__((packed));
 
+/*
+ * flags for fip_fka_desc.fd_flags
+ */
+enum fip_fka_flags {
+	FIP_FKA_ADV_D =	0x01,		/* no need for FKA from ENode */
+};
+
+/* FIP_DT_FKA flags */
+
 /*
  * FIP_DT_VENDOR descriptor.
  */

include/scsi/libfcoe.h

@@ -155,6 +155,7 @@ struct fcoe_fcf {
 	u8 pri;
 	u16 flags;
 	u32 fka_period;
+	u8 fd_flags:1;
 };
 
 /* FIP API functions */