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, 58 insertions, 12 deletions

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 02d654b..e28d40c 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -111,9 +111,20 @@ __FBSDID("$FreeBSD$");
 
 #include <security/mac/mac_framework.h>
 
-int	tcp_mssdflt = TCP_MSS;
+#ifdef VIMAGE_GLOBALS
+int	tcp_mssdflt;
 #ifdef INET6
-int	tcp_v6mssdflt = TCP6_MSS;
+int	tcp_v6mssdflt;
+#endif
+int	tcp_minmss;
+int	tcp_do_rfc1323;
+static int	icmp_may_rst;
+static int	tcp_isn_reseed_interval;
+static int	tcp_inflight_enable;
+static int	tcp_inflight_rttthresh;
+static int	tcp_inflight_min;
+static int	tcp_inflight_max;
+static int	tcp_inflight_stab;
 #endif
 
 static int
@@ -168,11 +179,9 @@ SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLTYPE_INT|CTLFLAG_RW,
  * with packet generation and sending. Set to zero to disable MINMSS
  * checking. This setting prevents us from sending too small packets.
  */
-int	tcp_minmss = TCP_MINMSS;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, minmss,
     CTLFLAG_RW, tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
 
-int	tcp_do_rfc1323 = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323,
     CTLFLAG_RW, tcp_do_rfc1323, 0,
     "Enable rfc1323 (high performance TCP) extensions");
@@ -192,12 +201,10 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, pcbcount,
     CTLFLAG_RD, tcbinfo.ipi_count, 0, "Number of active PCBs");
 
-static int	icmp_may_rst = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, icmp_may_rst,
     CTLFLAG_RW, icmp_may_rst, 0,
     "Certain ICMP unreachable messages may abort connections in SYN_SENT");
 
-static int	tcp_isn_reseed_interval = 0;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, isn_reseed_interval,
     CTLFLAG_RW, tcp_isn_reseed_interval, 0,
     "Seconds between reseeding of ISN secret");
@@ -210,7 +217,6 @@ SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, isn_reseed_interval,
 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, inflight, CTLFLAG_RW, 0,
     "TCP inflight data limiting");
 
-static int	tcp_inflight_enable = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, enable,
     CTLFLAG_RW, tcp_inflight_enable, 0,
     "Enable automatic TCP inflight data limiting");
@@ -219,20 +225,16 @@ static int	tcp_inflight_debug = 0;
 SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW,
     &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
 
-static int	tcp_inflight_rttthresh;
 SYSCTL_PROC(_net_inet_tcp_inflight, OID_AUTO, rttthresh, CTLTYPE_INT|CTLFLAG_RW,
     &tcp_inflight_rttthresh, 0, sysctl_msec_to_ticks, "I",
     "RTT threshold below which inflight will deactivate itself");
 
-static int	tcp_inflight_min = 6144;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, min,
     CTLFLAG_RW, tcp_inflight_min, 0, "Lower-bound for TCP inflight window");
 
-static int	tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, max,
     CTLFLAG_RW, tcp_inflight_max, 0, "Upper-bound for TCP inflight window");
 
-static int	tcp_inflight_stab = 20;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, stab,
     CTLFLAG_RW, tcp_inflight_stab, 0,
     "Inflight Algorithm Stabilization 20 = 2 packets");
@@ -297,8 +299,49 @@ void
 tcp_init(void)
 {
 	INIT_VNET_INET(curvnet);
+	int hashsize;
+
+	V_blackhole = 0;
+	V_tcp_delack_enabled = 1;
+	V_drop_synfin = 0;
+	V_tcp_do_rfc3042 = 1;
+	V_tcp_do_rfc3390 = 1;
+	V_tcp_do_ecn = 0;
+	V_tcp_ecn_maxretries = 1;
+	V_tcp_insecure_rst = 0;
+	V_tcp_do_autorcvbuf = 1;
+	V_tcp_autorcvbuf_inc = 16*1024;
+	V_tcp_autorcvbuf_max = 256*1024;
+
+	V_tcp_mssdflt = TCP_MSS;
+#ifdef INET6
+	V_tcp_v6mssdflt = TCP6_MSS;
+#endif
+	V_tcp_minmss = TCP_MINMSS;
+	V_tcp_do_rfc1323 = 1;
+	V_icmp_may_rst = 1;
+	V_tcp_isn_reseed_interval = 0;
+	V_tcp_inflight_enable = 1;
+	V_tcp_inflight_min = 6144;
+	V_tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
+	V_tcp_inflight_stab = 20;
+
+	V_path_mtu_discovery = 1;
+	V_ss_fltsz = 1;
+	V_ss_fltsz_local = 4;
+	V_tcp_do_newreno = 1;
+	V_tcp_do_tso = 1;
+	V_tcp_do_autosndbuf = 1;
+	V_tcp_autosndbuf_inc = 8*1024;
+	V_tcp_autosndbuf_max = 256*1024;
+
+	V_nolocaltimewait = 0;
+
+	V_tcp_do_sack = 1;
+	V_tcp_sack_maxholes = 128;
+	V_tcp_sack_globalmaxholes = 65536;
+	V_tcp_sack_globalholes = 0;
 
-	int hashsize = TCBHASHSIZE;
 	tcp_delacktime = TCPTV_DELACK;
 	tcp_keepinit = TCPTV_KEEP_INIT;
 	tcp_keepidle = TCPTV_KEEP_IDLE;
@@ -315,6 +358,7 @@ tcp_init(void)
 	INP_INFO_LOCK_INIT(&V_tcbinfo, "tcp");
 	LIST_INIT(&V_tcb);
 	V_tcbinfo.ipi_listhead = &V_tcb;
+	hashsize = TCBHASHSIZE;
 	TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
 	if (!powerof2(hashsize)) {
 		printf("WARNING: TCB hash size not a power of 2\n");
@@ -1429,10 +1473,12 @@ tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 #define ISN_STATIC_INCREMENT 4096
 #define ISN_RANDOM_INCREMENT (4096 - 1)
 
+#ifdef VIMAGE_GLOBALS
 static u_char isn_secret[32];
 static int isn_last_reseed;
 static u_int32_t isn_offset, isn_offset_old;
 static MD5_CTX isn_ctx;
+#endif
 
 tcp_seq
 tcp_new_isn(struct tcpcb *tp)