tcp: fix ssthresh u16 leftover

It was once upon time so that snd_sthresh was a 16-bit quantity.
...That has not been true for long period of time. I run across
some ancient compares which still seem to trust such legacy.
Put all that magic into a single place, I hopefully found all
of them.

Compile tested, though linking of allyesconfig is ridiculous
nowadays it seems.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index b71a446..56b7602 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -793,6 +793,13 @@ static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
        return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
 }
 
+#define TCP_INFINITE_SSTHRESH  0x7fffffff
+
+static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp)
+{
+       return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
+}
+
 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
  * The exception is rate halving phase, when cwnd is decreasing towards
  * ssthresh.

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index edeea06..19a0612 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2012,7 +2012,7 @@ int tcp_disconnect(struct sock *sk, int flags)
        tp->snd_cwnd = 2;
        icsk->icsk_probes_out = 0;
        tp->packets_out = 0;
-       tp->snd_ssthresh = 0x7fffffff;
+       tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        tp->snd_cwnd_cnt = 0;
        tp->bytes_acked = 0;
        tcp_set_ca_state(sk, TCP_CA_Open);

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index af6d6fa..d86784b 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -761,7 +761,7 @@ void tcp_update_metrics(struct sock *sk)
                        set_dst_metric_rtt(dst, RTAX_RTTVAR, var);
                }
 
-               if (tp->snd_ssthresh >= 0xFFFF) {
+               if (tcp_in_initial_slowstart(tp)) {
                        /* Slow start still did not finish. */
                        if (dst_metric(dst, RTAX_SSTHRESH) &&
                            !dst_metric_locked(dst, RTAX_SSTHRESH) &&

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0543561..7cda24b 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1808,7 +1808,7 @@ static int tcp_v4_init_sock(struct sock *sk)
        /* See draft-stevens-tcpca-spec-01 for discussion of the
         * initialization of these values.
         */
-       tp->snd_ssthresh = 0x7fffffff;  /* Infinity */
+       tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        tp->snd_cwnd_clamp = ~0;
        tp->mss_cache = 536;
 
@@ -2284,7 +2284,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
                jiffies_to_clock_t(icsk->icsk_ack.ato),
                (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
                tp->snd_cwnd,
-               tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh,
+               tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
                len);
 }
 

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index e48c37d..045bcfd 100644 (file)
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -410,7 +410,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
                newtp->retrans_out = 0;
                newtp->sacked_out = 0;
                newtp->fackets_out = 0;
-               newtp->snd_ssthresh = 0x7fffffff;
+               newtp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
 
                /* So many TCP implementations out there (incorrectly) count the
                 * initial SYN frame in their delayed-ACK and congestion control

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7718a92..21d100b 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1846,7 +1846,7 @@ static int tcp_v6_init_sock(struct sock *sk)
        /* See draft-stevens-tcpca-spec-01 for discussion of the
         * initialization of these values.
         */
-       tp->snd_ssthresh = 0x7fffffff;
+       tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        tp->snd_cwnd_clamp = ~0;
        tp->mss_cache = 536;
 
@@ -1969,7 +1969,8 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
                   jiffies_to_clock_t(icsk->icsk_rto),
                   jiffies_to_clock_t(icsk->icsk_ack.ato),
                   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
-                  tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
+                  tp->snd_cwnd,
+                  tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
                   );
 }