ifq: real ifq_start (drain+transmit), dequeue cookie fix, pf_kifq_input hook in the data path; 14/14 suite unchanged

module/compat/pfk_ifq.c

@@ -360,14 +360,16 @@ ifq_deq_begin(struct ifqueue *ifq)
 	if (!ifq->ifq_ops || !ifq->ifq_ops->ifqop_deq_begin)
 		return NULL;
 	m = ifq->ifq_ops->ifqop_deq_begin(ifq, &cookie);
+	ifq->ifq_dequeue = cookie;
 	return m;
 }
 
 void
 ifq_deq_commit(struct ifqueue *ifq, struct mbuf *m)
 {
-	void *cookie = NULL;
+	void *cookie = ifq->ifq_dequeue;
 
+	ifq->ifq_dequeue = NULL;
 	if (ifq->ifq_ops && ifq->ifq_ops->ifqop_deq_commit)
 		ifq->ifq_ops->ifqop_deq_commit(ifq, m, cookie);
 }
@@ -389,12 +391,47 @@ ifq_dequeue(struct ifqueue *ifq)
 	return m;
 }
 
+/*
+ * Drain the queue as far as the scheduler allows and hand each packet to the
+ * stack's output path.  OpenBSD calls if_start from softint context; here it
+ * runs either from the pf work queue (enqueue side) or from the scheduler's
+ * deferred timeout (pacing side), which is what makes hfsc's bandwidth
+ * limits take effect.
+ */
 void
 ifq_start(struct ifqueue *ifq)
 {
+	struct mbuf *m;
+
+	ifq->ifq_oactive = 1;
+	while ((m = ifq_dequeue(ifq)) != NULL) {
+		if (pfk_ifq_transmit(ifq, m))
+			break;			/* device busy: packet kept */
+	}
 	ifq->ifq_oactive = 0;
 }
 
+/*
+ * pf data-path entry: hand a packet to the interface's scheduler when one is
+ * attached (a pf `queue' rule is configured).  Returns 1 when the queue took
+ * ownership of m, 0 when the caller must keep going (priq/no scheduler).
+ */
+int
+pf_kifq_input(struct pfk_ifnet *ifp, struct mbuf *m)
+{
+	struct ifqueue *ifq;
+
+	if (ifp == NULL || m == NULL)
+		return 0;
+	ifq = &ifp->if_snd;
+	if (ifq->ifq_ops == NULL || ifq->ifq_ops == ifq_priq_ops)
+		return 0;			/* no scheduler: fast path */
+	if (ifq_enqueue(ifq, m) != 0)
+		return 1;			/* dropped by the queue: owned */
+	ifq_start(ifq);
+	return 1;
+}
+
 unsigned int
 ifq_purge(struct ifqueue *ifq)
 {

module/compat/pfk_xmit.c

@@ -270,3 +270,40 @@ pfk_if_output(struct pfk_ifnet *ifp, struct mbuf *m, void *dst,
 		m_freem(mp);
 	return err;
 }
+
+/*
+ * Transmit one queued packet.  Called from ifq_start() - i.e. from the pf
+ * work queue or from a scheduler's deferred timeout - and always consumes the
+ * mbuf.  Returns 0 (keep draining); a scheduler that wants to defer does so by
+ * simply not returning a packet from ifqop_deq_begin().
+ */
+int
+pfk_ifq_transmit(struct ifqueue *ifq, struct mbuf *m)
+{
+	struct sk_buff *skb = m_to_skb(m);
+	struct dst_entry *d;
+
+	(void)ifq;
+	if (skb == NULL) {
+		m_freem(m);
+		return 0;
+	}
+	d = skb_dst(skb);
+	if (d == NULL || IS_ERR(d) || d->dev == NULL || !netif_running(d->dev)) {
+		m_freem(m);
+		return 0;
+	}
+	skb->dev = d->dev;
+	skb_reset_network_header(skb);
+	if (skb->protocol == 0)
+		skb->protocol = htons(ip_hdr(skb)->protocol == IPPROTO_IPV6 ?
+		    ETH_P_IPV6 : ETH_P_IP);
+	/* the stack owns skb->cb (IPCB) from here; pf already tested it */
+	memset(skb->cb, 0, sizeof(skb->cb));
+	skb->mark |= PFK_DONE_OUT;
+	skb_get(skb);		/* the output path consumes one reference */
+	m->skb = NULL;		/* the mbuf's reference moves to the stack */
+	m_freem(m);
+	d->output(&init_net, NULL, skb);
+	return 0;
+}

module/include/compat/net/ifq.h

@@ -27,6 +27,7 @@ struct ifqueue {
 	struct mbuf_list	*ifq_free;	/* free list (unused in the port) */
 	unsigned int		 ifq_len;
 	unsigned int		 ifq_oactive;
+	void			*ifq_dequeue;	/* cookie between deq_begin/commit */
 
 	/* statistics */
 	u_int64_t		 ifq_packets;

module/include/pfk.h

@@ -1237,6 +1237,8 @@ struct fqcodel_stats {
  * queue when it owns the interface queue, NULL otherwise. */
 void	*ifq_q_enter(struct ifqueue *, const struct ifq_ops *);
 void	 ifq_q_leave(struct ifqueue *, void *);
+int	 pfk_ifq_transmit(struct ifqueue *, struct mbuf *);
+int	 pf_kifq_input(struct pfk_ifnet *, struct mbuf *);
 
 
 /*

module/pfsrc/pfk_hooks.c

@@ -204,6 +204,22 @@ pfk_pkt_work(struct work_struct *w)
 
 
 	if (m == m0) {
+		/*
+		 * Queueing: when a pf `queue' rule attached a scheduler to the
+		 * egress interface, hand the packet to it instead of sending it
+		 * straight out - this is what makes bandwidth limits real.
+		 */
+		if (action == PF_PASS && pk->dir == PF_OUT &&
+		    pskb_may_pull(pk->skb, sizeof(struct iphdr)) &&
+		    skb_dst(pk->skb) && !IS_ERR(skb_dst(pk->skb)) &&
+		    pf_kifq_input(skb_dst(pk->skb)->dev ?
+			pfk_ifp_bydev(skb_dst(pk->skb)->dev) : NULL, m)) {
+			orig = pk->skb;
+			pk->skb = NULL;		/* the queue owns the packet */
+			kfree_skb(orig);
+			kfree(pk);
+			return;
+		}
 		/* same buffer, possibly rewritten in place: our wrapper
 		 * held one extra skb reference — release it */
 		m_freem(m);