mpathpersist: Fix REPORT CAPABILITIES output

mpathpersist was incorrectly parsing the REPORT CAPABILITES service
action output. In reality, the type mask is two bytes where the type
information is stored in bits 7, 6, 5, 3, & 1 (0xea) of the first byte
and bit 0 (0x01) of the second byte. libmpathpersist was treating these
two bytes as a big endian 16 bit number, but mpathpersist was looking
for bits in that number as if it was little endian number.

Ideally, libmpathpersist would treat prin_capdescr.pr_type_mask as
two bytes, like it does for the flags. But we already expose this
as a 16 bit number, where we treated the input bytes as a big endian
number. There's no great reason to mess with the libmpathpersist API,
when we can just make mpathpersist treat this data like libmpathpersist
provides it. So, fix mpathpersist to print the data out correctly.

Additionally, instead of printing a 1 or a 0 to indicate if a type was
supported or not, it was printing the value of the type flag. Also,
Persist Through Power Loss Capable (PTPL_C) was being reported if any
bit in flags[0] was set. Fix these as well. Reformat all of the
capability printing lines, since it is less confusing than only
reformatting some of them.

Fixes: ae4e8a6 ("mpathpersist: Add new utility for managing persistent reservation on dm multipath device")
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

Author: bmarzins

libmpathpersist/mpath_persist.h

@@ -113,7 +113,9 @@ struct prin_capdescr
 {
 	uint16_t length;
 	uint8_t  flags[2];
-	uint16_t pr_type_mask;
+	uint16_t pr_type_mask; /* The two bytes of the type mask are treated
+				  as a single big-endian number. So the valid
+				  type bits are 0xea01 */
 	uint16_t _reserved;
 };
 

mpathpersist/main.c

@@ -748,25 +748,42 @@ void mpath_print_buf_readcap( struct prin_resp *pr_buff)
 
 	printf("Report capabilities response:\n");
 
-	printf("  Compatible Reservation Handling(CRH): %d\n", !!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x10));
-	printf("  Specify Initiator Ports Capable(SIP_C): %d\n",!!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x8));
-	printf("  All Target Ports Capable(ATP_C): %d\n",!!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x4 ));
-	printf("  Persist Through Power Loss Capable(PTPL_C): %d\n",!!(pr_buff->prin_descriptor.prin_readcap.flags[0]));
-	printf("  Type Mask Valid(TMV): %d\n", !!(pr_buff->prin_descriptor.prin_readcap.flags[1] & 0x80));
-	printf("  Allow Commands: %d\n", !!(( pr_buff->prin_descriptor.prin_readcap.flags[1] >> 4) & 0x7));
+	printf("  Compatible Reservation Handling(CRH): %d\n",
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x10));
+	printf("  Specify Initiator Ports Capable(SIP_C): %d\n",
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x8));
+	printf("  All Target Ports Capable(ATP_C): %d\n",
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x4));
+	printf("  Persist Through Power Loss Capable(PTPL_C): %d\n",
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[0] & 0x1));
+	printf("  Type Mask Valid(TMV): %d\n",
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[1] & 0x80));
+	printf("  Allow Commands: %d\n",
+	       !!((pr_buff->prin_descriptor.prin_readcap.flags[1] >> 4) & 0x7));
 	printf("  Persist Through Power Loss Active(PTPL_A): %d\n",
-			!!(pr_buff->prin_descriptor.prin_readcap.flags[1] & 0x1));
+	       !!(pr_buff->prin_descriptor.prin_readcap.flags[1] & 0x1));
 
 	if(pr_buff->prin_descriptor.prin_readcap.flags[1] & 0x80)
 	{
 		printf("    Support indicated in Type mask:\n");
 
-		printf("      %s: %d\n", pr_type_strs[7], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x80);
-		printf("      %s: %d\n", pr_type_strs[6], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x40);
-		printf("      %s: %d\n", pr_type_strs[5], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x20);
-		printf("      %s: %d\n", pr_type_strs[3], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x8);
-		printf("      %s: %d\n", pr_type_strs[1], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x2);
-		printf("      %s: %d\n", pr_type_strs[8], pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x100);
+		printf("      %s: %d\n", pr_type_strs[7],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask &
+			  0x8000));
+		printf("      %s: %d\n", pr_type_strs[6],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask &
+			  0x4000));
+		printf("      %s: %d\n", pr_type_strs[5],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask &
+			  0x2000));
+		printf("      %s: %d\n", pr_type_strs[3],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask &
+			  0x800));
+		printf("      %s: %d\n", pr_type_strs[1],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask &
+			  0x200));
+		printf("      %s: %d\n", pr_type_strs[8],
+		       !!(pr_buff->prin_descriptor.prin_readcap.pr_type_mask & 0x1));
 	}
 }