Implement an upper limit for packets per second sent by node.

2 files changed, 47 insertions, 4 deletions

diff --git a/sys/netgraph/ng_source.c b/sys/netgraph/ng_source.c
index 16c10bb..2413a5d 100644
--- a/sys/netgraph/ng_source.c
+++ b/sys/netgraph/ng_source.c
@@ -181,6 +181,13 @@ static const struct ng_cmdlist ng_source_cmds[] = {
 	  &ng_parse_string_type,
 	  NULL
 	},
+	{
+	  NGM_SOURCE_COOKIE,
+	  NGM_SOURCE_SETPPS,
+	  "setpps",
+	  &ng_parse_uint32_type,
+	  NULL
+	},
 	{ 0 }
 };
 
@@ -352,6 +359,21 @@ ng_source_rcvmsg(node_p node, item_p item, hook_p lasthook)
 			ng_source_store_output_ifp(sc, ifname);
 			break;
 		    }
+		case NGM_SOURCE_SETPPS:
+		    {
+			uint32_t pps;
+
+			if (msg->header.arglen != sizeof(uint32_t)) {
+				error = EINVAL;
+				break;
+			}
+
+			pps = *(uint32_t *)msg->data;
+
+			sc->stats.maxPps = pps;
+
+			break;
+		    }
 		default:
 			error = EINVAL;
 			break;
@@ -548,6 +570,7 @@ ng_source_start(sc_p sc, uint64_t packets)
 	timevalclear(&sc->stats.elapsedTime);
 	timevalclear(&sc->stats.endTime);
 	getmicrotime(&sc->stats.startTime);
+	getmicrotime(&sc->stats.lastTime);
 	ng_callout(&sc->intr_ch, sc->node, NULL, 0,
 	    ng_source_intr, sc, 0);
 
@@ -593,6 +616,21 @@ ng_source_intr(node_p node, hook_p hook, void *arg1, int arg2)
 	} else
 		packets = sc->snd_queue.ifq_len;
 
+	if (sc->stats.maxPps != 0) {
+		struct timeval	now, elapsed;
+		uint64_t	usec;
+		int		maxpkt;
+
+		getmicrotime(&now);
+		elapsed = now;
+		timevalsub(&elapsed, &sc->stats.lastTime);
+		usec = elapsed.tv_sec * 1000000 + elapsed.tv_usec;
+		maxpkt = (uint64_t)sc->stats.maxPps * usec / 1000000;
+		sc->stats.lastTime = now;
+		if (packets > maxpkt)
+			packets = maxpkt;
+	}
+
 	ng_source_send(sc, packets, NULL);
 	if (sc->packets == 0)
 		ng_source_stop(sc);
diff --git a/sys/netgraph/ng_source.h b/sys/netgraph/ng_source.h
index 0d84f06..fcfb151 100644
--- a/sys/netgraph/ng_source.h
+++ b/sys/netgraph/ng_source.h
@@ -52,13 +52,15 @@
 
 /* Statistics structure returned by NGM_SOURCE_GET_STATS */
 struct ng_source_stats {
-	u_int64_t	outOctets;
-	u_int64_t	outFrames;
-	u_int32_t	queueOctets;
-	u_int32_t	queueFrames;
+	uint64_t	outOctets;
+	uint64_t	outFrames;
+	uint32_t	queueOctets;
+	uint32_t	queueFrames;
+	uint32_t	maxPps;
 	struct timeval	startTime;
 	struct timeval	endTime;
 	struct timeval	elapsedTime;
+	struct timeval	lastTime;
 };
 
 extern const struct ng_parse_type ng_source_timeval_type;
@@ -68,9 +70,11 @@ extern const struct ng_parse_type ng_source_timeval_type;
 	  { "outFrames",	&ng_parse_uint64_type	},	\
 	  { "queueOctets",	&ng_parse_uint32_type	},	\
 	  { "queueFrames",	&ng_parse_uint32_type	},	\
+	  { "maxPps",		&ng_parse_uint32_type	},	\
 	  { "startTime",	&ng_source_timeval_type },	\
 	  { "endTime",		&ng_source_timeval_type },	\
 	  { "elapsedTime",	&ng_source_timeval_type },	\
+	  { "lastTime",		&ng_source_timeval_type },	\
 	  { NULL }						\
 }
 
@@ -83,6 +87,7 @@ enum {
 	NGM_SOURCE_STOP,		/* stop sending queued data */
 	NGM_SOURCE_CLR_DATA,		/* clear the queued data */
 	NGM_SOURCE_SETIFACE,		/* configure downstream iface */
+	NGM_SOURCE_SETPPS,		/* rate-limiting packets per second */
 };
 
 #endif /* _NETGRAPH_NG_SOURCE_H_ */