Change the initialization methodology for global variables scheduled

for virtualization.

Instead of initializing the affected global variables at instatiation,
assign initial values to them in initializer functions.  As a rule,
initialization at instatiation for such variables should never be
introduced again from now on.  Furthermore, enclose all instantiations
of such global variables in #ifdef VIMAGE_GLOBALS blocks.

Essentialy, this change should have zero functional impact.  In the next
phase of merging network stack virtualization infrastructure from
p4/vimage branch, the new initialization methology will allow us to
switch between using global variables and their counterparts residing in
virtualization containers with minimum code churn, and in the long run
allow us to intialize multiple instances of such container structures.

Discussed at:	devsummit Strassburg
Reviewed by:	bz, julian
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation

1 files changed, 17 insertions, 12 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index a7515ef..4c17f10d 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -99,7 +99,21 @@ __FBSDID("$FreeBSD$");
 
 static const int tcprexmtthresh = 3;
 
+#ifdef VIMAGE_GLOBALS
 struct	tcpstat tcpstat;
+int	blackhole;
+int	tcp_delack_enabled;
+int	drop_synfin;
+int	tcp_do_rfc3042;
+int	tcp_do_rfc3390;
+int	tcp_do_ecn;
+int	tcp_ecn_maxretries;
+int	tcp_insecure_rst;
+int	tcp_do_autorcvbuf;
+int	tcp_autorcvbuf_inc;
+int	tcp_autorcvbuf_max;
+#endif
+
 SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_tcp, TCPCTL_STATS, stats,
     CTLFLAG_RW, tcpstat , tcpstat,
     "TCP statistics (struct tcpstat, netinet/tcp_var.h)");
@@ -108,59 +122,50 @@ int tcp_log_in_vain = 0;
 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_in_vain, CTLFLAG_RW,
     &tcp_log_in_vain, 0, "Log all incoming TCP segments to closed ports");
 
-static int blackhole = 0;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, blackhole, CTLFLAG_RW,
     blackhole, 0, "Do not send RST on segments to closed ports");
 
-int tcp_delack_enabled = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, delayed_ack,
     CTLFLAG_RW, tcp_delack_enabled, 0,
     "Delay ACK to try and piggyback it onto a data packet");
 
-static int drop_synfin = 0;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, drop_synfin,
     CTLFLAG_RW, drop_synfin, 0, "Drop TCP packets with SYN+FIN set");
 
-static int tcp_do_rfc3042 = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, rfc3042, CTLFLAG_RW,
     tcp_do_rfc3042, 0, "Enable RFC 3042 (Limited Transmit)");
 
-static int tcp_do_rfc3390 = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
     tcp_do_rfc3390, 0,
     "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
 
-int	tcp_do_ecn = 0;
-int	tcp_ecn_maxretries = 1;
 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, ecn, CTLFLAG_RW, 0, "TCP ECN");
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_ecn, OID_AUTO, enable,
     CTLFLAG_RW, tcp_do_ecn, 0, "TCP ECN support");
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_ecn, OID_AUTO, maxretries,
     CTLFLAG_RW, tcp_ecn_maxretries, 0, "Max retries before giving up on ECN");
 
-static int tcp_insecure_rst = 0;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, insecure_rst,
     CTLFLAG_RW, tcp_insecure_rst, 0,
     "Follow the old (insecure) criteria for accepting RST packets");
 
-int	tcp_do_autorcvbuf = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, recvbuf_auto,
     CTLFLAG_RW, tcp_do_autorcvbuf, 0,
     "Enable automatic receive buffer sizing");
 
-int	tcp_autorcvbuf_inc = 16*1024;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, recvbuf_inc,
     CTLFLAG_RW, tcp_autorcvbuf_inc, 0,
     "Incrementor step size of automatic receive buffer");
 
-int	tcp_autorcvbuf_max = 256*1024;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, recvbuf_max,
     CTLFLAG_RW, tcp_autorcvbuf_max, 0,
     "Max size of automatic receive buffer");
 
+#ifdef VIMAGE_GLOBALS
 struct inpcbhead tcb;
-#define	tcb6	tcb  /* for KAME src sync over BSD*'s */
 struct inpcbinfo tcbinfo;
+#endif
+#define	tcb6	tcb  /* for KAME src sync over BSD*'s */
 
 static void	 tcp_dooptions(struct tcpopt *, u_char *, int, int);
 static void	 tcp_do_segment(struct mbuf *, struct tcphdr *,