tcp: Prefer IW parameters in routing entries

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 79dafc2..a40ae29 100644 (file)
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -158,6 +158,9 @@ KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
 #define logtcp(name)   KTR_LOG(tcp_ ## name)
 */
 
+#define TCP_IW_MAXSEGS_DFLT    4
+#define TCP_IW_CAPSEGS_DFLT    3
+
 struct inpcbinfo tcbinfo[MAXCPU];
 struct tcpcbackqhead tcpcbackq[MAXCPU];
 
@@ -251,11 +254,11 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
     &tcp_do_rfc3390, 0,
     "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
 
-static u_long tcp_iw_maxsegs = 4;
+static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
     &tcp_iw_maxsegs, 0, "TCP IW segments max");
 
-static u_long tcp_iw_capsegs = 3;
+static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
     &tcp_iw_capsegs, 0, "TCP IW segments");
 
@@ -1972,8 +1975,40 @@ tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
        tp->snd_bwnd = bwnd;
 }
 
+static void
+tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
+{
+       struct rtentry *rt;
+       struct inpcb *inp = tp->t_inpcb;
+#ifdef INET6
+       boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
+#else
+       const boolean_t isipv6 = FALSE;
+#endif
+
+       /* XXX */
+       if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
+               tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
+       if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
+               tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
+
+       if (isipv6)
+               rt = tcp_rtlookup6(&inp->inp_inc);
+       else
+               rt = tcp_rtlookup(&inp->inp_inc);
+       if (rt == NULL ||
+           rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
+           rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
+               *maxsegs = tcp_iw_maxsegs;
+               *capsegs = tcp_iw_capsegs;
+               return;
+       }
+       *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
+       *capsegs = rt->rt_rmx.rmx_iwcapsegs;
+}
+
 u_long
-tcp_initial_window(const struct tcpcb *tp)
+tcp_initial_window(struct tcpcb *tp)
 {
        if (tcp_do_rfc3390) {
                /*
@@ -2003,9 +2038,11 @@ tcp_initial_window(const struct tcpcb *tp)
                if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
                        return (2 * tp->t_maxseg);
                } else {
-                       return min(tcp_iw_maxsegs * tp->t_maxseg,
-                                  max(2 * tp->t_maxseg,
-                                      tcp_iw_capsegs * 1460));
+                       u_long maxsegs, capsegs;
+
+                       tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
+                       return min(maxsegs * tp->t_maxseg,
+                                  max(2 * tp->t_maxseg, capsegs * 1460));
                }
        } else {
                /*

diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 3ae9fd8..4253462 100644 (file)
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -656,7 +656,7 @@ struct tcpcb *
 void    tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *,
                        int);
 void    tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
-u_long  tcp_initial_window(const struct tcpcb *tp);
+u_long  tcp_initial_window(struct tcpcb *tp);
 void    tcp_timer_keep_activity(struct tcpcb *tp, int thflags);
 void    syncache_init(void);
 void    syncache_unreach(struct in_conninfo *, struct tcphdr *);