-Put the optimized soreceive_stream() under a compile time option called

TCP_SORECEIVE_STREAM for the time being.

Requested by:	brooks

Once compiled in make it easily switchable for testers by using a tuneable
 net.inet.tcp.soreceive_stream
and a corresponding read-only sysctl to report the current state.

Suggested by:	rwatson

MFC after:	2 days
-This line, and those below, will be ignored--
> Description of fields to fill in above:                     76 columns --|
> PR:            If a GNATS PR is affected by the change.
> Submitted by:  If someone else sent in the change.
> Reviewed by:   If someone else reviewed your modification.
> Approved by:   If you needed approval for this commit.
> Obtained from: If the change is from a third party.
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> Security:      Vulnerability reference (one per line) or description.
> Empty fields above will be automatically removed.

M    sys/conf/options
M    sys/kern/uipc_socket.c
M    sys/netinet/tcp_subr.c
M    sys/netinet/tcp_usrreq.c

1 files changed, 2 insertions, 0 deletions

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index d11af34..34d5edc 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1870,6 +1870,7 @@ release:
 /*
  * Optimized version of soreceive() for stream (TCP) sockets.
  */
+#ifdef TCP_SORECEIVE_STREAM
 int
 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
@@ -2062,6 +2063,7 @@ out:
 	sbunlock(sb);
 	return (error);
 }
+#endif /* TCP_SORECEIVE_STREAM */
 
 /*
  * Optimized version of soreceive() for simple datagram cases from userspace.