Retire IP_RSSCPUID ; the right thing to do is query the RSS bucket;

map the bucket to an RSS queue, then map the queue to a CPU ID.
This way the bucket->queue and queue->CPU mapping can change
over time.

Introduce IP_RSSBUCKETID - which instead looks up the RSS bucket.
User applications can then map the RSS bucket to a CPU.

2 files changed, 12 insertions, 6 deletions

diff --git a/sys/netinet/in.h b/sys/netinet/in.h
index 08809d5..5f6708d 100644
--- a/sys/netinet/in.h
+++ b/sys/netinet/in.h
@@ -468,9 +468,10 @@ __END_DECLS
 #define	IP_MINTTL		66   /* minimum TTL for packet or drop */
 #define	IP_DONTFRAG		67   /* don't fragment packet */
 #define	IP_RECVTOS		68   /* bool; receive IP TOS w/dgram */
-#define	IP_FLOWID		69   /* flow id for the given socket/inp */
-#define	IP_FLOWTYPE		70   /* flow type (M_HASHTYPE) */
-#define	IP_RSSCPUID		71   /* RSS flowid -> CPU id mapping */
+#define	IP_FLOWID		69   /* get flow id for the given socket/inp */
+#define	IP_FLOWTYPE		70   /* get flow type (M_HASHTYPE) */
+/* 71 - XXX was IP_RSSCPUID - can recycle whenever */
+#define	IP_RSSBUCKETID		72   /* get RSS flowid -> bucket mapping */
 
 /* IPv4 Source Filter Multicast API [RFC3678] */
 #define	IP_ADD_SOURCE_MEMBERSHIP	70   /* join a source-specific group */
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index 168fc98..44b40cb 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1244,9 +1244,14 @@ ip_ctloutput(struct socket *so, struct sockopt *sopt)
 				optval = inp->inp_flowtype;
 				break;
 #ifdef	RSS
-			case IP_RSSCPUID:
-				optval = rss_hash2cpuid(inp->inp_flowid,
-				    inp->inp_flowtype);
+			case IP_RSSBUCKETID:
+				retval = rss_hash2bucket(inp->inp_flowid,
+				    inp->inp_flowtype,
+				    &rss_bucket);
+				if (retval == 0)
+					optval = rss_bucket;
+				else
+					error = EINVAL;
 				break;
 #endif
 			}