[src/trunk]: src/sys/net wg: Add altq hooks.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e1973394cfed
branches:  trunk
changeset: 1014221:e1973394cfed
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Sep 14 04:57:20 2020 +0000

description:
wg: Add altq hooks.

While here, remove the IFQ_CLASSIFY bottleneck (takes the ifq lock,
so it would serialize all transmission to all peers on a single wg(4)
interface).

altq can be disabled at compile-time or at run-time; even if included
at comple-time the run-time impact should be negligible if disabled.

diffstat:

 sys/net/if_wg.c |  66 +++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 60 insertions(+), 6 deletions(-)

diffs (131 lines):

diff -r b73efc2886e6 -r e1973394cfed sys/net/if_wg.c
--- a/sys/net/if_wg.c   Mon Sep 14 01:19:50 2020 +0000
+++ b/sys/net/if_wg.c   Mon Sep 14 04:57:20 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wg.c,v 1.59 2020/09/13 17:18:54 riastradh Exp $     */
+/*     $NetBSD: if_wg.c,v 1.60 2020/09/14 04:57:20 riastradh Exp $     */
 
 /*
  * Copyright (C) Ryota Ozaki <ozaki.ryota%gmail.com@localhost>
@@ -41,9 +41,10 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.59 2020/09/13 17:18:54 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.60 2020/09/14 04:57:20 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
+#include "opt_altq_enabled.h"
 #include "opt_inet.h"
 #endif
 
@@ -702,6 +703,9 @@
 static int     wg_ioctl(struct ifnet *, u_long, void *);
 static int     wg_bind_port(struct wg_softc *, const uint16_t);
 static int     wg_init(struct ifnet *);
+#ifdef ALTQ
+static void    wg_start(struct ifnet *);
+#endif
 static void    wg_stop(struct ifnet *, int);
 
 static void    wg_peer_work(struct work *, void *);
@@ -3537,11 +3541,16 @@
        wg->wg_if.if_ioctl = wg_ioctl;
        wg->wg_if.if_output = wg_output;
        wg->wg_if.if_init = wg_init;
+#ifdef ALTQ
+       wg->wg_if.if_start = wg_start;
+#endif
        wg->wg_if.if_stop = wg_stop;
        wg->wg_if.if_type = IFT_OTHER;
        wg->wg_if.if_dlt = DLT_NULL;
        wg->wg_if.if_softc = wg;
+#ifdef ALTQ
        IFQ_SET_READY(&wg->wg_if.if_snd);
+#endif
 
        error = if_initialize(&wg->wg_if);
        if (error != 0)
@@ -3780,7 +3789,12 @@
                goto out0;
        }
 
-       IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
+#ifdef ALTQ
+       bool altq = atomic_load_relaxed(&ifp->if_snd.altq_flags)
+           & ALTQF_ENABLED;
+       if (altq)
+               IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
+#endif
 
        bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
 
@@ -3819,18 +3833,36 @@
        }
 
        /* There's an established session.  Toss it in the queue.  */
+#ifdef ALTQ
+       if (altq) {
+               mutex_enter(ifp->if_snd.ifq_lock);
+               if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
+                       M_SETCTX(m, wgp);
+                       ALTQ_ENQUEUE(&ifp->if_snd, m, error);
+                       m = NULL; /* consume */
+               }
+               mutex_exit(ifp->if_snd.ifq_lock);
+               if (m == NULL) {
+                       wg_start(ifp);
+                       goto out2;
+               }
+       }
+#endif
        kpreempt_disable();
        const uint32_t h = curcpu()->ci_index;  // pktq_rps_hash(m)
        M_SETCTX(m, wgp);
        if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
                WGLOG(LOG_ERR, "pktq full, dropping\n");
                error = ENOBUFS;
-               goto out2;
+               goto out3;
        }
        m = NULL;               /* consumed */
        error = 0;
-out2:  kpreempt_enable();
-
+out3:  kpreempt_enable();
+
+#ifdef ALTQ
+out2:
+#endif
        wg_put_session(wgs, &wgs_psref);
 out1:  wg_put_peer(wgp, &wgp_psref);
 out0:  if (m)
@@ -4688,6 +4720,28 @@
        return 0;
 }
 
+#ifdef ALTQ
+static void
+wg_start(struct ifnet *ifp)
+{
+       struct mbuf *m;
+
+       for (;;) {
+               IFQ_DEQUEUE(&ifp->if_snd, m);
+               if (m == NULL)
+                       break;
+
+               kpreempt_disable();
+               const uint32_t h = curcpu()->ci_index;  // pktq_rps_hash(m)
+               if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
+                       WGLOG(LOG_ERR, "pktq full, dropping\n");
+                       m_freem(m);
+               }
+               kpreempt_enable();
+       }
+}
+#endif
+
 static void
 wg_stop(struct ifnet *ifp, int disable)
 {