git: 3da0d11afe08 - stable/11 - netgraph/ng_source: If queue is full, don't enqueue

[Lutz Donnerhacke]

The branch stable/11 has been updated by donner:

URL: https://cgit.FreeBSD.org/src/commit/?id=3da0d11afe0807ccbbb9f447e6c814dce654d71d

commit 3da0d11afe0807ccbbb9f447e6c814dce654d71d
Author:     Lutz Donnerhacke <donner at FreeBSD.org>
AuthorDate: 2021-01-23 17:54:47 +0000
Commit:     Lutz Donnerhacke <donner at FreeBSD.org>
CommitDate: 2021-05-09 13:45:07 +0000

    netgraph/ng_source: If queue is full, don't enqueue
    
    Submitted by: nc
    Reviewed by: donner, kp
    Differential Revision: https://reviews.freebsd.org/D23477
    
    (cherry picked from commit d7dd28bb09fa51b9958a5dc288d2aeef56a67491)
---
 sys/netgraph/ng_source.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/sys/netgraph/ng_source.c b/sys/netgraph/ng_source.c
index da8f42381ac3..8d1d05b5673f 100644
--- a/sys/netgraph/ng_source.c
+++ b/sys/netgraph/ng_source.c
@@ -284,7 +284,7 @@ ng_source_constructor(node_p node)
 
 	NG_NODE_SET_PRIVATE(node, sc);
 	sc->node = node;
-	sc->snd_queue.ifq_maxlen = 2048;	/* XXX not checked */
+	sc->snd_queue.ifq_maxlen = 2048;
 	ng_callout_init(&sc->intr_ch);
 
 	return (0);
@@ -567,8 +567,11 @@ ng_source_rcvdata(hook_p hook, item_p item)
 	}
 	KASSERT(hook == sc->input, ("%s: no hook!", __func__));
 
-	/* Enqueue packet. */
-	/* XXX should we check IF_QFULL() ? */
+	/* Enqueue packet if the queue isn't full. */
+	if (_IF_QFULL(&sc->snd_queue)) {
+		NG_FREE_M(m);
+		return (ENOBUFS);
+	}
 	_IF_ENQUEUE(&sc->snd_queue, m);
 	sc->queueOctets += m->m_pkthdr.len;
 	sc->last_packet = m;