[PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Rainer Baumann]

Trace Control for Netem: Emulate network properties such as long range dependency and self-similarity of cross-traffic.

kernel space:
The delay, drop, duplication and corruption values are readout in user space and sent to kernel space via configfs. The userspace process will "hang on write" until the kernel needs new data.

In order to have always packet action values ready to apply, there are two buffers that hold these values. Packet action values can be read from one buffer and the other buffer can be refilled with new values simultaneously. The synchronization of "need more delay values" and "return from write" is done with the use of wait queues.

Having applied the delay value to a packet, the packet gets processed by the original netem functions.

Signed-off-by: Rainer Baumann <baumann@tik.ee.ethz.ch>

---

Patch for linux kernel 2.6.17.13: http://tcn.hypert.net/tcn_kernel_configfs.patch

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Stephen Hemminger]

Some changes:

1. need to select CONFIGFS into configuration
2. don't add declarations after code.
3. use unsigned not int for counters and mask.
4. don't return a structure (ie pkt_delay)
5. use enum for magic values
6. don't use GFP_ATOMIC unless you have to
7. check error values on configfs_init
8. map initialization is unneeded. static's always init to zero.

------------------
diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index d10f353..a51de64 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -430,6 +430,8 @@ enum
 	TCA_NETEM_DELAY_DIST,
 	TCA_NETEM_REORDER,
 	TCA_NETEM_CORRUPT,
+	TCA_NETEM_TRACE,
+	TCA_NETEM_STATS,
 	__TCA_NETEM_MAX,
 };
 
@@ -445,6 +447,35 @@ struct tc_netem_qopt
 	__u32	jitter;		/* random jitter in latency (us) */
 };
 
+struct tc_netem_stats
+{
+	int packetcount;
+	int packetok;
+	int normaldelay;
+	int drops;
+	int dupl;
+	int corrupt;
+	int novaliddata;
+	int uninitialized;
+	int bufferunderrun;
+	int bufferinuseempty;
+	int noemptybuffer;
+	int readbehindbuffer;
+	int buffer1_reloads;
+	int buffer2_reloads;
+	int tobuffer1_switch;
+	int tobuffer2_switch;
+	int switch_to_emptybuffer1;
+	int switch_to_emptybuffer2;				   		
+};	
+
+struct tc_netem_trace
+{
+	__u32   fid;             /*flowid */
+	__u32   def;          	 /* default action 0 = no delay, 1 = drop*/
+	__u32   ticks;	         /* number of ticks corresponding to 1ms */
+};
+
 struct tc_netem_corr
 {
 	__u32	delay_corr;	/* delay correlation */
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 8298ea9..aee4bc6 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -232,6 +232,7 @@ config NET_SCH_DSMARK
 
 config NET_SCH_NETEM
 	tristate "Network emulator (NETEM)"
+	select CONFIGFS_FS
 	---help---
 	  Say Y if you want to emulate network delay, loss, and packet
 	  re-ordering. This is often useful to simulate networks when
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 45939ba..521b9e3 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -11,6 +11,9 @@
  *
  * Authors:	Stephen Hemminger <shemminger@osdl.org>
  *		Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
+ *              netem trace enhancement: Ariane Keller <arkeller@ee.ethz.ch> ETH Zurich
+ *                                       Rainer Baumann <baumann@hypert.net> ETH Zurich
+ *                                       Ulrich Fiedler <fiedler@tik.ee.ethz.ch> ETH Zurich
  */
 
 #include <linux/module.h>
@@ -21,10 +24,16 @@ #include <linux/errno.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/rtnetlink.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/configfs.h>
+#include <linux/vmalloc.h>
 
 #include <net/pkt_sched.h>
 
-#define VERSION "1.2"
+#include "net/flowseed.h"
+
+#define VERSION "1.3"
 
 /*	Network Emulation Queuing algorithm.
 	====================================
@@ -50,6 +59,11 @@ #define VERSION "1.2"
 
 	 The simulator is limited by the Linux timer resolution
 	 and will create packet bursts on the HZ boundary (1ms).
+
+	 The trace option allows us to read the values for packet delay,
+	 duplication, loss and corruption from a tracefile. This permits
+	 the modulation of statistical properties such as long-range 
+	 dependences. See http://tcn.hypert.net.
 */
 
 struct netem_sched_data {
@@ -65,6 +79,11 @@ struct netem_sched_data {
 	u32 duplicate;
 	u32 reorder;
 	u32 corrupt;
+	u32 tcnstop;
+	u32 trace;
+	u32 ticks;
+	u32 def;
+	u32 newdataneeded;
 
 	struct crndstate {
 		unsigned long last;
@@ -72,9 +91,13 @@ struct netem_sched_data {
 	} delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;
 
 	struct disttable {
-		u32  size;
+		u32 size;
 		s16 table[0];
 	} *delay_dist;
+
+	struct tcn_statistic *statistic;
+	struct tcn_control *flowbuffer;
+	wait_queue_head_t my_event;
 };
 
 /* Time stamp put into socket buffer control block */
@@ -82,6 +105,18 @@ struct netem_skb_cb {
 	psched_time_t	time_to_send;
 };
 
+
+struct confdata {
+	int fid;
+	struct netem_sched_data * sched_data;
+};
+
+static struct confdata map[MAX_FLOWS];
+
+#define MASK_BITS	29
+#define MASK_DELAY	((1<<MASK_BITS)-1)
+#define MASK_HEAD       ~MASK_DELAY
+
 /* init_crandom - initialize correlated random number generator
  * Use entropy source for initial seed.
  */
@@ -139,6 +174,103 @@ static long tabledist(unsigned long mu, 
 	return  x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
 }
 
+/* don't call this function directly. It is called after 
+ * a packet has been taken out of a buffer and it was the last. 
+ */
+static int reload_flowbuffer (struct netem_sched_data *q)
+{
+	struct tcn_control *flow = q->flowbuffer;
+
+	if (flow->buffer_in_use == flow->buffer1) {
+		flow->buffer1_empty = flow->buffer1;
+		if (flow->buffer2_empty) {
+			q->statistic->switch_to_emptybuffer2++;
+			return -EFAULT;
+		}
+
+		q->statistic->tobuffer2_switch++;
+
+		flow->buffer_in_use = flow->buffer2;
+		flow->offsetpos = flow->buffer2;
+
+	} else {
+		flow->buffer2_empty = flow->buffer2;
+
+		if (flow->buffer1_empty) {
+		 	q->statistic->switch_to_emptybuffer1++;
+			return -EFAULT;
+		} 
+
+		q->statistic->tobuffer1_switch++;
+
+		flow->buffer_in_use = flow->buffer1;
+		flow->offsetpos = flow->buffer1;
+
+	}
+	/*the flowseed process can send more data*/
+	q->tcnstop = 0;
+	q->newdataneeded = 1;
+	wake_up(&q->my_event);
+	return 0;
+}
+
+/* return pktdelay with delay and drop/dupl/corrupt option */
+static int get_next_delay(struct netem_sched_data *q, enum tcn_flow *head)
+{
+	struct tcn_control *flow = q->flowbuffer;
+	u32 variout;
+
+	/*choose whether to drop or 0 delay packets on default*/
+	*head = q->def;
+
+	if (!flow) {
+		printk(KERN_ERR "netem: read from an uninitialized flow.\n");
+		q->statistic->uninitialized++;
+		return 0;
+	}
+
+	q->statistic->packetcount++;
+
+	/* check if we have to reload a buffer */
+	if (flow->offsetpos - flow->buffer_in_use == DATA_PACKAGE)
+		reload_flowbuffer(q);
+
+	/* sanity checks */
+	if ((flow->buffer_in_use == flow->buffer1 && flow->validdataB1) 
+	    || ( flow->buffer_in_use == flow->buffer2 && flow->validdataB2)) {
+
+		if (flow->buffer1_empty && flow->buffer2_empty) {
+			q->statistic->bufferunderrun++;
+			return 0;
+		}
+
+		if (flow->buffer1_empty == flow->buffer_in_use ||
+		    flow->buffer2_empty == flow->buffer_in_use) {
+			q->statistic->bufferinuseempty++;
+			return 0;
+		}
+
+		if (flow->offsetpos - flow->buffer_in_use >=
+		    DATA_PACKAGE) {
+			q->statistic->readbehindbuffer++;
+			return 0;
+		}
+		/*end of tracefile reached*/	
+	} else {
+		q->statistic->novaliddata++;
+		return 0;
+	}
+
+	/* now it's safe to read */
+	variout = *flow->offsetpos++;
+	*head = (variout & MASK_HEAD) >> MASK_BITS;
+
+	(&q->statistic->normaldelay)[*head] += 1;
+	q->statistic->packetok++;
+
+	return ((variout & MASK_DELAY) * q->ticks) / 1000;
+}
+
 /*
  * Insert one skb into qdisc.
  * Note: parent depends on return value to account for queue length.
@@ -148,20 +280,25 @@ static long tabledist(unsigned long mu, 
 static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
-	/* We don't fill cb now as skb_unshare() may invalidate it */
 	struct netem_skb_cb *cb;
 	struct sk_buff *skb2;
-	int ret;
-	int count = 1;
+	enum tcn_flow action = FLOW_NORMAL;
+	psched_tdiff_t delay;
+	int ret, count = 1;
 
 	pr_debug("netem_enqueue skb=%p\n", skb);
 
-	/* Random duplication */
-	if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor))
+	if (q->trace) 
+		action = get_next_delay(q, &delay);
+
+ 	/* Random duplication */
+	if (q->trace ? action == FLOW_DUP :
+	    (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)))
 		++count;
 
 	/* Random packet drop 0 => none, ~0 => all */
-	if (q->loss && q->loss >= get_crandom(&q->loss_cor))
+	if (q->trace ? action == FLOW_DROP :
+	    (q->loss && q->loss >= get_crandom(&q->loss_cor)))
 		--count;
 
 	if (count == 0) {
@@ -190,7 +327,8 @@ static int netem_enqueue(struct sk_buff 
 	 * If packet is going to be hardware checksummed, then
 	 * do it now in software before we mangle it.
 	 */
-	if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
+	if (q->trace ? action == FLOW_MANGLE :
+	    (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor))) {
 		if (!(skb = skb_unshare(skb, GFP_ATOMIC))
 		    || (skb->ip_summed == CHECKSUM_PARTIAL
 			&& skb_checksum_help(skb))) {
@@ -206,10 +344,10 @@ static int netem_enqueue(struct sk_buff 
 	    || q->counter < q->gap 	/* inside last reordering gap */
 	    || q->reorder < get_crandom(&q->reorder_cor)) {
 		psched_time_t now;
-		psched_tdiff_t delay;
 
-		delay = tabledist(q->latency, q->jitter,
-				  &q->delay_cor, q->delay_dist);
+		if (!q->trace)
+			delay = tabledist(q->latency, q->jitter,
+					  &q->delay_cor, q->delay_dist);
 
 		PSCHED_GET_TIME(now);
 		PSCHED_TADD2(now, delay, cb->time_to_send);
@@ -343,6 +481,65 @@ static int set_fifo_limit(struct Qdisc *
 	return ret;
 }
 
+static void reset_stats(struct netem_sched_data * q)
+{
+	memset(q->statistic, 0, sizeof(*(q->statistic)));
+	return;
+}
+
+static void free_flowbuffer(struct netem_sched_data * q)
+{
+	if (q->flowbuffer != NULL) {
+		q->tcnstop = 1;
+		q->newdataneeded = 1;
+		wake_up(&q->my_event);
+
+		if (q->flowbuffer->buffer1 != NULL) {
+			kfree(q->flowbuffer->buffer1);
+		}
+		if (q->flowbuffer->buffer2 != NULL) {
+			kfree(q->flowbuffer->buffer2);
+		}
+		kfree(q->flowbuffer);
+		kfree(q->statistic);
+		q->flowbuffer = NULL;
+		q->statistic = NULL;
+	}
+}
+
+static int init_flowbuffer(unsigned int fid, struct netem_sched_data * q)
+{
+	int i, flowid = -1;
+
+	q->statistic = kzalloc(sizeof(*(q->statistic)), GFP_KERNEL;
+	init_waitqueue_head(&q->my_event);
+
+	for(i = 0; i < MAX_FLOWS; i++) {
+		if(map[i].fid == 0) {
+			flowid = i;
+			map[i].fid = fid;
+			map[i].sched_data = q;
+			break;
+		}
+	}
+
+	if (flowid != -1) {
+		q->flowbuffer = kmalloc(sizeof(*(q->flowbuffer)), GFP_KERNEL);
+		q->flowbuffer->buffer1 = kmalloc(DATA_PACKAGE, GFP_KERNEL);
+		q->flowbuffer->buffer2 = kmalloc(DATA_PACKAGE, GFP_KERNEL);
+
+		q->flowbuffer->buffer_in_use = q->flowbuffer->buffer1;
+		q->flowbuffer->offsetpos = q->flowbuffer->buffer1;
+		q->flowbuffer->buffer1_empty = q->flowbuffer->buffer1;
+		q->flowbuffer->buffer2_empty = q->flowbuffer->buffer2;
+		q->flowbuffer->flowid = flowid; 
+		q->flowbuffer->validdataB1 = 0;
+		q->flowbuffer->validdataB2 = 0;
+	}
+
+	return flowid;
+}
+
 /*
  * Distribution data is a variable size payload containing
  * signed 16 bit values.
@@ -414,6 +611,32 @@ static int get_corrupt(struct Qdisc *sch
 	return 0;
 }
 
+static int get_trace(struct Qdisc *sch, const struct rtattr *attr)
+{
+	struct netem_sched_data *q = qdisc_priv(sch);
+	const struct tc_netem_trace *traceopt = RTA_DATA(attr);
+
+	if (RTA_PAYLOAD(attr) != sizeof(*traceopt))
+		return -EINVAL;
+
+	if (traceopt->fid) {
+		/*correction us -> ticks*/
+		q->ticks = traceopt->ticks;
+		int ind;
+		ind = init_flowbuffer(traceopt->fid, q);
+		if(ind < 0) {
+			printk("netem: maximum number of traces:%d"
+			       " change in net/flowseedprocfs.h\n", MAX_FLOWS);
+			return -EINVAL;
+		}
+		q->trace = ind + 1;
+
+	} else
+		q->trace = 0;
+	q->def = traceopt->def;
+	return 0;
+}
+
 /* Parse netlink message to set options */
 static int netem_change(struct Qdisc *sch, struct rtattr *opt)
 {
@@ -431,6 +654,14 @@ static int netem_change(struct Qdisc *sc
 		return ret;
 	}
 	
+	if (q->trace) {
+		int temp = q->trace - 1;
+		q->trace = 0;
+		map[temp].fid = 0;
+		reset_stats(q);
+		free_flowbuffer(q);
+	}
+
 	q->latency = qopt->latency;
 	q->jitter = qopt->jitter;
 	q->limit = qopt->limit;
@@ -477,6 +708,11 @@ static int netem_change(struct Qdisc *sc
 			if (ret)
 				return ret;
 		}
+		if (tb[TCA_NETEM_TRACE-1]) {
+			ret = get_trace(sch, tb[TCA_NETEM_TRACE-1]);
+			if (ret)
+				return ret;
+		}
 	}
 
 	return 0;
@@ -572,6 +808,7 @@ static int netem_init(struct Qdisc *sch,
 	q->timer.function = netem_watchdog;
 	q->timer.data = (unsigned long) sch;
 
+	q->trace = 0;
 	q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops);
 	if (!q->qdisc) {
 		pr_debug("netem: qdisc create failed\n");
@@ -590,6 +827,12 @@ static void netem_destroy(struct Qdisc *
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
 
+	if (q->trace) {
+		int temp = q->trace - 1;
+		q->trace = 0;
+		map[temp].fid = 0;
+		free_flowbuffer(q);
+	}
 	del_timer_sync(&q->timer);
 	qdisc_destroy(q->qdisc);
 	kfree(q->delay_dist);
@@ -604,6 +847,7 @@ static int netem_dump(struct Qdisc *sch,
 	struct tc_netem_corr cor;
 	struct tc_netem_reorder reorder;
 	struct tc_netem_corrupt corrupt;
+	struct tc_netem_trace traceopt;
 
 	qopt.latency = q->latency;
 	qopt.jitter = q->jitter;
@@ -626,6 +870,35 @@ static int netem_dump(struct Qdisc *sch,
 	corrupt.correlation = q->corrupt_cor.rho;
 	RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
 
+	traceopt.fid = q->trace;
+	traceopt.def = q->def;
+	traceopt.ticks = q->ticks;
+	RTA_PUT(skb, TCA_NETEM_TRACE, sizeof(traceopt), &traceopt);
+
+	if (q->trace) {
+		struct tc_netem_stats tstats;
+
+		tstats.packetcount = q->statistic->packetcount;
+		tstats.packetok = q->statistic->packetok;
+		tstats.normaldelay = q->statistic->normaldelay;
+		tstats.drops = q->statistic->drops;
+		tstats.dupl = q->statistic->dupl;
+		tstats.corrupt = q->statistic->corrupt;
+		tstats.novaliddata = q->statistic->novaliddata;
+		tstats.uninitialized = q->statistic->uninitialized;
+		tstats.bufferunderrun = q->statistic->bufferunderrun;
+		tstats.bufferinuseempty = q->statistic->bufferinuseempty;
+		tstats.noemptybuffer = q->statistic->noemptybuffer;
+		tstats.readbehindbuffer = q->statistic->readbehindbuffer;
+		tstats.buffer1_reloads = q->statistic->buffer1_reloads;
+		tstats.buffer2_reloads = q->statistic->buffer2_reloads;
+		tstats.tobuffer1_switch = q->statistic->tobuffer1_switch;
+		tstats.tobuffer2_switch = q->statistic->tobuffer2_switch;
+		tstats.switch_to_emptybuffer1 = q->statistic->switch_to_emptybuffer1;
+		tstats.switch_to_emptybuffer2 = q->statistic->switch_to_emptybuffer2;
+		RTA_PUT(skb, TCA_NETEM_STATS, sizeof(tstats), &tstats);
+	}
+
 	rta->rta_len = skb->tail - b;
 
 	return skb->len;
@@ -709,6 +982,173 @@ static struct tcf_proto **netem_find_tcf
 	return NULL;
 }
 
+/*configfs to read tcn delay values from userspace*/
+struct tcn_flow {
+	struct config_item item;
+};
+
+static struct tcn_flow *to_tcn_flow(struct config_item *item)
+{
+	return item ? container_of(item, struct tcn_flow, item) : NULL;
+}
+
+static struct configfs_attribute tcn_flow_attr_storeme = {
+	.ca_owner = THIS_MODULE,
+	.ca_name = "delayvalue",
+	.ca_mode = S_IRUGO | S_IWUSR,
+};
+
+static struct configfs_attribute *tcn_flow_attrs[] = {
+	&tcn_flow_attr_storeme,
+	NULL,
+};
+
+static ssize_t tcn_flow_attr_store(struct config_item *item,
+				       struct configfs_attribute *attr,
+				       const char *page, size_t count)
+{
+	char *p = (char *)page;
+	int fid, i, validData = 0;
+	int flowid = -1;
+	struct tcn_control *checkbuf;
+
+	if (count != DATA_PACKAGE_ID) {
+		printk("netem: Unexpected data received. %d\n", count);
+		return -EMSGSIZE;
+	}
+
+	memcpy(&fid, p + DATA_PACKAGE, sizeof(int));
+	memcpy(&validData, p + DATA_PACKAGE + sizeof(int), sizeof(int));
+
+	/* check whether this flow is registered */
+	for (i = 0; i < MAX_FLOWS; i++) {
+		if (map[i].fid == fid) {
+			flowid = i;
+			break;
+		}
+	}
+	/* exit if flow is not registered */
+	if (flowid < 0) {
+		printk("netem: Invalid FID received. Killing process.\n");
+		return -EINVAL;
+	}
+
+	checkbuf = map[flowid].sched_data->flowbuffer;
+	if (checkbuf == NULL) {
+		printk("netem: no flow registered");
+		return -ENOBUFS;
+	}
+
+	/* check if flowbuffer has empty buffer and copy data into it */
+	if (checkbuf->buffer1_empty != NULL) {
+		memcpy(checkbuf->buffer1, p, DATA_PACKAGE);
+		checkbuf->buffer1_empty = NULL;
+		checkbuf->validdataB1 = validData;
+		map[flowid].sched_data->statistic->buffer1_reloads++;
+
+	} else if (checkbuf->buffer2_empty != NULL) {
+		memcpy(checkbuf->buffer2, p, DATA_PACKAGE);
+		checkbuf->buffer2_empty = NULL;
+		checkbuf->validdataB2 = validData;
+		map[flowid].sched_data->statistic->buffer2_reloads++;
+
+	} else {
+		printk("netem: flow %d: no empty buffer. data loss.\n", flowid);
+		map[flowid].sched_data->statistic->noemptybuffer++;
+	}
+
+	if (validData) {
+		/* on initialization both buffers need data */
+		if (checkbuf->buffer2_empty != NULL) {
+			return DATA_PACKAGE_ID;
+		}
+		/* wait until new data is needed */
+		wait_event(map[flowid].sched_data->my_event,
+			   map[flowid].sched_data->newdataneeded);
+		map[flowid].sched_data->newdataneeded = 0;
+
+	}
+
+	if (map[flowid].sched_data->tcnstop) {
+		return -ECANCELED;
+	}
+
+	return DATA_PACKAGE_ID;
+
+}
+
+static void tcn_flow_release(struct config_item *item)
+{
+	kfree(to_tcn_flow(item));
+
+}
+
+static struct configfs_item_operations tcn_flow_item_ops = {
+	.release = tcn_flow_release,
+	.store_attribute = tcn_flow_attr_store,
+};
+
+static struct config_item_type tcn_flow_type = {
+	.ct_item_ops = &tcn_flow_item_ops,
+	.ct_attrs = tcn_flow_attrs,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item * tcn_make_item(struct config_group *group,
+						     const char *name)
+{
+	struct tcn_flow *tcn_flow;
+
+	tcn_flow = kmalloc(sizeof(struct tcn_flow), GFP_KERNEL);
+	if (!tcn_flow)
+		return NULL;
+
+	memset(tcn_flow, 0, sizeof(struct tcn_flow));
+
+	config_item_init_type_name(&tcn_flow->item, name,
+				   &tcn_flow_type);
+	return &tcn_flow->item;
+}
+
+static struct configfs_group_operations tcn_group_ops = {
+	.make_item = tcn_make_item,
+};
+
+static struct config_item_type tcn_type = {
+	.ct_group_ops = &tcn_group_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem tcn_subsys = {
+	.su_group = {
+		     .cg_item = {
+				 .ci_namebuf = "tcn",
+				 .ci_type = &tcn_type,
+				 },
+		     },
+};
+
+static __init int configfs_init(void)
+{
+	int ret;
+	struct configfs_subsystem *subsys = &tcn_subsys;
+
+	config_group_init(&subsys->su_group);
+	init_MUTEX(&subsys->su_sem);
+	ret = configfs_register_subsystem(subsys);
+	if (ret) {
+		printk(KERN_ERR "Error %d while registering subsystem %s\n",
+		       ret, subsys->su_group.cg_item.ci_namebuf);
+		configfs_unregister_subsystem(&tcn_subsys);
+	}
+	return ret;
+}
+
+static void configfs_exit(void)
+{
+	configfs_unregister_subsystem(&tcn_subsys);
+}
+
 static struct Qdisc_class_ops netem_class_ops = {
 	.graft		=	netem_graft,
 	.leaf		=	netem_leaf,
@@ -740,11 +1180,17 @@ static struct Qdisc_ops netem_qdisc_ops 
 
 static int __init netem_module_init(void)
 {
+	int err;
+
 	pr_info("netem: version " VERSION "\n");
+	err = configfs_init();
+	if (err)
+		return err;
 	return register_qdisc(&netem_qdisc_ops);
 }
 static void __exit netem_module_exit(void)
 {
+	configfs_exit();
 	unregister_qdisc(&netem_qdisc_ops);
 }
 module_init(netem_module_init)

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Rainer Baumann]

Hi Stephens

We merged your changes into our patch
http://tcn.hypert.net/tcn_kernel_2_6_18.patch
Please let us know if we should do further adoptions to our
implementation and/or resubmit the adapted patch.

Cheers+thanx,
Rainer

Stephen Hemminger wrote:
> Some changes:
>
> 1. need to select CONFIGFS into configuration
> 2. don't add declarations after code.
> 3. use unsigned not int for counters and mask.
> 4. don't return a structure (ie pkt_delay)
> 5. use enum for magic values
> 6. don't use GFP_ATOMIC unless you have to
> 7. check error values on configfs_init
> 8. map initialization is unneeded. static's always init to zero.
>
> ------------------
> diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
> index d10f353..a51de64 100644
> --- a/include/linux/pkt_sched.h
> +++ b/include/linux/pkt_sched.h
> @@ -430,6 +430,8 @@ enum
>  	TCA_NETEM_DELAY_DIST,
>  	TCA_NETEM_REORDER,
>  	TCA_NETEM_CORRUPT,
> +	TCA_NETEM_TRACE,
> +	TCA_NETEM_STATS,
>  	__TCA_NETEM_MAX,
>  };
>  
> @@ -445,6 +447,35 @@ struct tc_netem_qopt
>  	__u32	jitter;		/* random jitter in latency (us) */
>  };
>  
> +struct tc_netem_stats
> +{
> +	int packetcount;
> +	int packetok;
> +	int normaldelay;
> +	int drops;
> +	int dupl;
> +	int corrupt;
> +	int novaliddata;
> +	int uninitialized;
> +	int bufferunderrun;
> +	int bufferinuseempty;
> +	int noemptybuffer;
> +	int readbehindbuffer;
> +	int buffer1_reloads;
> +	int buffer2_reloads;
> +	int tobuffer1_switch;
> +	int tobuffer2_switch;
> +	int switch_to_emptybuffer1;
> +	int switch_to_emptybuffer2;				   		
> +};	
> +
> +struct tc_netem_trace
> +{
> +	__u32   fid;             /*flowid */
> +	__u32   def;          	 /* default action 0 = no delay, 1 = drop*/
> +	__u32   ticks;	         /* number of ticks corresponding to 1ms */
> +};
> +
>  struct tc_netem_corr
>  {
>  	__u32	delay_corr;	/* delay correlation */
> diff --git a/net/sched/Kconfig b/net/sched/Kconfig
> index 8298ea9..aee4bc6 100644
> --- a/net/sched/Kconfig
> +++ b/net/sched/Kconfig
> @@ -232,6 +232,7 @@ config NET_SCH_DSMARK
>  
>  config NET_SCH_NETEM
>  	tristate "Network emulator (NETEM)"
> +	select CONFIGFS_FS
>  	---help---
>  	  Say Y if you want to emulate network delay, loss, and packet
>  	  re-ordering. This is often useful to simulate networks when
> diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
> index 45939ba..521b9e3 100644
> --- a/net/sched/sch_netem.c
> +++ b/net/sched/sch_netem.c
> @@ -11,6 +11,9 @@
>   *
>   * Authors:	Stephen Hemminger <shemminger@osdl.org>
>   *		Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
> + *              netem trace enhancement: Ariane Keller <arkeller@ee.ethz.ch> ETH Zurich
> + *                                       Rainer Baumann <baumann@hypert.net> ETH Zurich
> + *                                       Ulrich Fiedler <fiedler@tik.ee.ethz.ch> ETH Zurich
>   */
>  
>  #include <linux/module.h>
> @@ -21,10 +24,16 @@ #include <linux/errno.h>
>  #include <linux/netdevice.h>
>  #include <linux/skbuff.h>
>  #include <linux/rtnetlink.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/configfs.h>
> +#include <linux/vmalloc.h>
>  
>  #include <net/pkt_sched.h>
>  
> -#define VERSION "1.2"
> +#include "net/flowseed.h"
> +
> +#define VERSION "1.3"
>  
>  /*	Network Emulation Queuing algorithm.
>  	====================================
> @@ -50,6 +59,11 @@ #define VERSION "1.2"
>  
>  	 The simulator is limited by the Linux timer resolution
>  	 and will create packet bursts on the HZ boundary (1ms).
> +
> +	 The trace option allows us to read the values for packet delay,
> +	 duplication, loss and corruption from a tracefile. This permits
> +	 the modulation of statistical properties such as long-range 
> +	 dependences. See http://tcn.hypert.net.
>  */
>  
>  struct netem_sched_data {
> @@ -65,6 +79,11 @@ struct netem_sched_data {
>  	u32 duplicate;
>  	u32 reorder;
>  	u32 corrupt;
> +	u32 tcnstop;
> +	u32 trace;
> +	u32 ticks;
> +	u32 def;
> +	u32 newdataneeded;
>  
>  	struct crndstate {
>  		unsigned long last;
> @@ -72,9 +91,13 @@ struct netem_sched_data {
>  	} delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;
>  
>  	struct disttable {
> -		u32  size;
> +		u32 size;
>  		s16 table[0];
>  	} *delay_dist;
> +
> +	struct tcn_statistic *statistic;
> +	struct tcn_control *flowbuffer;
> +	wait_queue_head_t my_event;
>  };
>  
>  /* Time stamp put into socket buffer control block */
> @@ -82,6 +105,18 @@ struct netem_skb_cb {
>  	psched_time_t	time_to_send;
>  };
>  
> +
> +struct confdata {
> +	int fid;
> +	struct netem_sched_data * sched_data;
> +};
> +
> +static struct confdata map[MAX_FLOWS];
> +
> +#define MASK_BITS	29
> +#define MASK_DELAY	((1<<MASK_BITS)-1)
> +#define MASK_HEAD       ~MASK_DELAY
> +
>  /* init_crandom - initialize correlated random number generator
>   * Use entropy source for initial seed.
>   */
> @@ -139,6 +174,103 @@ static long tabledist(unsigned long mu, 
>  	return  x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
>  }
>  
> +/* don't call this function directly. It is called after 
> + * a packet has been taken out of a buffer and it was the last. 
> + */
> +static int reload_flowbuffer (struct netem_sched_data *q)
> +{
> +	struct tcn_control *flow = q->flowbuffer;
> +
> +	if (flow->buffer_in_use == flow->buffer1) {
> +		flow->buffer1_empty = flow->buffer1;
> +		if (flow->buffer2_empty) {
> +			q->statistic->switch_to_emptybuffer2++;
> +			return -EFAULT;
> +		}
> +
> +		q->statistic->tobuffer2_switch++;
> +
> +		flow->buffer_in_use = flow->buffer2;
> +		flow->offsetpos = flow->buffer2;
> +
> +	} else {
> +		flow->buffer2_empty = flow->buffer2;
> +
> +		if (flow->buffer1_empty) {
> +		 	q->statistic->switch_to_emptybuffer1++;
> +			return -EFAULT;
> +		} 
> +
> +		q->statistic->tobuffer1_switch++;
> +
> +		flow->buffer_in_use = flow->buffer1;
> +		flow->offsetpos = flow->buffer1;
> +
> +	}
> +	/*the flowseed process can send more data*/
> +	q->tcnstop = 0;
> +	q->newdataneeded = 1;
> +	wake_up(&q->my_event);
> +	return 0;
> +}
> +
> +/* return pktdelay with delay and drop/dupl/corrupt option */
> +static int get_next_delay(struct netem_sched_data *q, enum tcn_flow *head)
> +{
> +	struct tcn_control *flow = q->flowbuffer;
> +	u32 variout;
> +
> +	/*choose whether to drop or 0 delay packets on default*/
> +	*head = q->def;
> +
> +	if (!flow) {
> +		printk(KERN_ERR "netem: read from an uninitialized flow.\n");
> +		q->statistic->uninitialized++;
> +		return 0;
> +	}
> +
> +	q->statistic->packetcount++;
> +
> +	/* check if we have to reload a buffer */
> +	if (flow->offsetpos - flow->buffer_in_use == DATA_PACKAGE)
> +		reload_flowbuffer(q);
> +
> +	/* sanity checks */
> +	if ((flow->buffer_in_use == flow->buffer1 && flow->validdataB1) 
> +	    || ( flow->buffer_in_use == flow->buffer2 && flow->validdataB2)) {
> +
> +		if (flow->buffer1_empty && flow->buffer2_empty) {
> +			q->statistic->bufferunderrun++;
> +			return 0;
> +		}
> +
> +		if (flow->buffer1_empty == flow->buffer_in_use ||
> +		    flow->buffer2_empty == flow->buffer_in_use) {
> +			q->statistic->bufferinuseempty++;
> +			return 0;
> +		}
> +
> +		if (flow->offsetpos - flow->buffer_in_use >=
> +		    DATA_PACKAGE) {
> +			q->statistic->readbehindbuffer++;
> +			return 0;
> +		}
> +		/*end of tracefile reached*/	
> +	} else {
> +		q->statistic->novaliddata++;
> +		return 0;
> +	}
> +
> +	/* now it's safe to read */
> +	variout = *flow->offsetpos++;
> +	*head = (variout & MASK_HEAD) >> MASK_BITS;
> +
> +	(&q->statistic->normaldelay)[*head] += 1;
> +	q->statistic->packetok++;
> +
> +	return ((variout & MASK_DELAY) * q->ticks) / 1000;
> +}
> +
>  /*
>   * Insert one skb into qdisc.
>   * Note: parent depends on return value to account for queue length.
> @@ -148,20 +280,25 @@ static long tabledist(unsigned long mu, 
>  static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
>  {
>  	struct netem_sched_data *q = qdisc_priv(sch);
> -	/* We don't fill cb now as skb_unshare() may invalidate it */
>  	struct netem_skb_cb *cb;
>  	struct sk_buff *skb2;
> -	int ret;
> -	int count = 1;
> +	enum tcn_flow action = FLOW_NORMAL;
> +	psched_tdiff_t delay;
> +	int ret, count = 1;
>  
>  	pr_debug("netem_enqueue skb=%p\n", skb);
>  
> -	/* Random duplication */
> -	if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor))
> +	if (q->trace) 
> +		action = get_next_delay(q, &delay);
> +
> + 	/* Random duplication */
> +	if (q->trace ? action == FLOW_DUP :
> +	    (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)))
>  		++count;
>  
>  	/* Random packet drop 0 => none, ~0 => all */
> -	if (q->loss && q->loss >= get_crandom(&q->loss_cor))
> +	if (q->trace ? action == FLOW_DROP :
> +	    (q->loss && q->loss >= get_crandom(&q->loss_cor)))
>  		--count;
>  
>  	if (count == 0) {
> @@ -190,7 +327,8 @@ static int netem_enqueue(struct sk_buff 
>  	 * If packet is going to be hardware checksummed, then
>  	 * do it now in software before we mangle it.
>  	 */
> -	if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
> +	if (q->trace ? action == FLOW_MANGLE :
> +	    (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor))) {
>  		if (!(skb = skb_unshare(skb, GFP_ATOMIC))
>  		    || (skb->ip_summed == CHECKSUM_PARTIAL
>  			&& skb_checksum_help(skb))) {
> @@ -206,10 +344,10 @@ static int netem_enqueue(struct sk_buff 
>  	    || q->counter < q->gap 	/* inside last reordering gap */
>  	    || q->reorder < get_crandom(&q->reorder_cor)) {
>  		psched_time_t now;
> -		psched_tdiff_t delay;
>  
> -		delay = tabledist(q->latency, q->jitter,
> -				  &q->delay_cor, q->delay_dist);
> +		if (!q->trace)
> +			delay = tabledist(q->latency, q->jitter,
> +					  &q->delay_cor, q->delay_dist);
>  
>  		PSCHED_GET_TIME(now);
>  		PSCHED_TADD2(now, delay, cb->time_to_send);
> @@ -343,6 +481,65 @@ static int set_fifo_limit(struct Qdisc *
>  	return ret;
>  }
>  
> +static void reset_stats(struct netem_sched_data * q)
> +{
> +	memset(q->statistic, 0, sizeof(*(q->statistic)));
> +	return;
> +}
> +
> +static void free_flowbuffer(struct netem_sched_data * q)
> +{
> +	if (q->flowbuffer != NULL) {
> +		q->tcnstop = 1;
> +		q->newdataneeded = 1;
> +		wake_up(&q->my_event);
> +
> +		if (q->flowbuffer->buffer1 != NULL) {
> +			kfree(q->flowbuffer->buffer1);
> +		}
> +		if (q->flowbuffer->buffer2 != NULL) {
> +			kfree(q->flowbuffer->buffer2);
> +		}
> +		kfree(q->flowbuffer);
> +		kfree(q->statistic);
> +		q->flowbuffer = NULL;
> +		q->statistic = NULL;
> +	}
> +}
> +
> +static int init_flowbuffer(unsigned int fid, struct netem_sched_data * q)
> +{
> +	int i, flowid = -1;
> +
> +	q->statistic = kzalloc(sizeof(*(q->statistic)), GFP_KERNEL;
> +	init_waitqueue_head(&q->my_event);
> +
> +	for(i = 0; i < MAX_FLOWS; i++) {
> +		if(map[i].fid == 0) {
> +			flowid = i;
> +			map[i].fid = fid;
> +			map[i].sched_data = q;
> +			break;
> +		}
> +	}
> +
> +	if (flowid != -1) {
> +		q->flowbuffer = kmalloc(sizeof(*(q->flowbuffer)), GFP_KERNEL);
> +		q->flowbuffer->buffer1 = kmalloc(DATA_PACKAGE, GFP_KERNEL);
> +		q->flowbuffer->buffer2 = kmalloc(DATA_PACKAGE, GFP_KERNEL);
> +
> +		q->flowbuffer->buffer_in_use = q->flowbuffer->buffer1;
> +		q->flowbuffer->offsetpos = q->flowbuffer->buffer1;
> +		q->flowbuffer->buffer1_empty = q->flowbuffer->buffer1;
> +		q->flowbuffer->buffer2_empty = q->flowbuffer->buffer2;
> +		q->flowbuffer->flowid = flowid; 
> +		q->flowbuffer->validdataB1 = 0;
> +		q->flowbuffer->validdataB2 = 0;
> +	}
> +
> +	return flowid;
> +}
> +
>  /*
>   * Distribution data is a variable size payload containing
>   * signed 16 bit values.
> @@ -414,6 +611,32 @@ static int get_corrupt(struct Qdisc *sch
>  	return 0;
>  }
>  
> +static int get_trace(struct Qdisc *sch, const struct rtattr *attr)
> +{
> +	struct netem_sched_data *q = qdisc_priv(sch);
> +	const struct tc_netem_trace *traceopt = RTA_DATA(attr);
> +
> +	if (RTA_PAYLOAD(attr) != sizeof(*traceopt))
> +		return -EINVAL;
> +
> +	if (traceopt->fid) {
> +		/*correction us -> ticks*/
> +		q->ticks = traceopt->ticks;
> +		int ind;
> +		ind = init_flowbuffer(traceopt->fid, q);
> +		if(ind < 0) {
> +			printk("netem: maximum number of traces:%d"
> +			       " change in net/flowseedprocfs.h\n", MAX_FLOWS);
> +			return -EINVAL;
> +		}
> +		q->trace = ind + 1;
> +
> +	} else
> +		q->trace = 0;
> +	q->def = traceopt->def;
> +	return 0;
> +}
> +
>  /* Parse netlink message to set options */
>  static int netem_change(struct Qdisc *sch, struct rtattr *opt)
>  {
> @@ -431,6 +654,14 @@ static int netem_change(struct Qdisc *sc
>  		return ret;
>  	}
>  	
> +	if (q->trace) {
> +		int temp = q->trace - 1;
> +		q->trace = 0;
> +		map[temp].fid = 0;
> +		reset_stats(q);
> +		free_flowbuffer(q);
> +	}
> +
>  	q->latency = qopt->latency;
>  	q->jitter = qopt->jitter;
>  	q->limit = qopt->limit;
> @@ -477,6 +708,11 @@ static int netem_change(struct Qdisc *sc
>  			if (ret)
>  				return ret;
>  		}
> +		if (tb[TCA_NETEM_TRACE-1]) {
> +			ret = get_trace(sch, tb[TCA_NETEM_TRACE-1]);
> +			if (ret)
> +				return ret;
> +		}
>  	}
>  
>  	return 0;
> @@ -572,6 +808,7 @@ static int netem_init(struct Qdisc *sch,
>  	q->timer.function = netem_watchdog;
>  	q->timer.data = (unsigned long) sch;
>  
> +	q->trace = 0;
>  	q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops);
>  	if (!q->qdisc) {
>  		pr_debug("netem: qdisc create failed\n");
> @@ -590,6 +827,12 @@ static void netem_destroy(struct Qdisc *
>  {
>  	struct netem_sched_data *q = qdisc_priv(sch);
>  
> +	if (q->trace) {
> +		int temp = q->trace - 1;
> +		q->trace = 0;
> +		map[temp].fid = 0;
> +		free_flowbuffer(q);
> +	}
>  	del_timer_sync(&q->timer);
>  	qdisc_destroy(q->qdisc);
>  	kfree(q->delay_dist);
> @@ -604,6 +847,7 @@ static int netem_dump(struct Qdisc *sch,
>  	struct tc_netem_corr cor;
>  	struct tc_netem_reorder reorder;
>  	struct tc_netem_corrupt corrupt;
> +	struct tc_netem_trace traceopt;
>  
>  	qopt.latency = q->latency;
>  	qopt.jitter = q->jitter;
> @@ -626,6 +870,35 @@ static int netem_dump(struct Qdisc *sch,
>  	corrupt.correlation = q->corrupt_cor.rho;
>  	RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
>  
> +	traceopt.fid = q->trace;
> +	traceopt.def = q->def;
> +	traceopt.ticks = q->ticks;
> +	RTA_PUT(skb, TCA_NETEM_TRACE, sizeof(traceopt), &traceopt);
> +
> +	if (q->trace) {
> +		struct tc_netem_stats tstats;
> +
> +		tstats.packetcount = q->statistic->packetcount;
> +		tstats.packetok = q->statistic->packetok;
> +		tstats.normaldelay = q->statistic->normaldelay;
> +		tstats.drops = q->statistic->drops;
> +		tstats.dupl = q->statistic->dupl;
> +		tstats.corrupt = q->statistic->corrupt;
> +		tstats.novaliddata = q->statistic->novaliddata;
> +		tstats.uninitialized = q->statistic->uninitialized;
> +		tstats.bufferunderrun = q->statistic->bufferunderrun;
> +		tstats.bufferinuseempty = q->statistic->bufferinuseempty;
> +		tstats.noemptybuffer = q->statistic->noemptybuffer;
> +		tstats.readbehindbuffer = q->statistic->readbehindbuffer;
> +		tstats.buffer1_reloads = q->statistic->buffer1_reloads;
> +		tstats.buffer2_reloads = q->statistic->buffer2_reloads;
> +		tstats.tobuffer1_switch = q->statistic->tobuffer1_switch;
> +		tstats.tobuffer2_switch = q->statistic->tobuffer2_switch;
> +		tstats.switch_to_emptybuffer1 = q->statistic->switch_to_emptybuffer1;
> +		tstats.switch_to_emptybuffer2 = q->statistic->switch_to_emptybuffer2;
> +		RTA_PUT(skb, TCA_NETEM_STATS, sizeof(tstats), &tstats);
> +	}
> +
>  	rta->rta_len = skb->tail - b;
>  
>  	return skb->len;
> @@ -709,6 +982,173 @@ static struct tcf_proto **netem_find_tcf
>  	return NULL;
>  }
>  
> +/*configfs to read tcn delay values from userspace*/
> +struct tcn_flow {
> +	struct config_item item;
> +};
> +
> +static struct tcn_flow *to_tcn_flow(struct config_item *item)
> +{
> +	return item ? container_of(item, struct tcn_flow, item) : NULL;
> +}
> +
> +static struct configfs_attribute tcn_flow_attr_storeme = {
> +	.ca_owner = THIS_MODULE,
> +	.ca_name = "delayvalue",
> +	.ca_mode = S_IRUGO | S_IWUSR,
> +};
> +
> +static struct configfs_attribute *tcn_flow_attrs[] = {
> +	&tcn_flow_attr_storeme,
> +	NULL,
> +};
> +
> +static ssize_t tcn_flow_attr_store(struct config_item *item,
> +				       struct configfs_attribute *attr,
> +				       const char *page, size_t count)
> +{
> +	char *p = (char *)page;
> +	int fid, i, validData = 0;
> +	int flowid = -1;
> +	struct tcn_control *checkbuf;
> +
> +	if (count != DATA_PACKAGE_ID) {
> +		printk("netem: Unexpected data received. %d\n", count);
> +		return -EMSGSIZE;
> +	}
> +
> +	memcpy(&fid, p + DATA_PACKAGE, sizeof(int));
> +	memcpy(&validData, p + DATA_PACKAGE + sizeof(int), sizeof(int));
> +
> +	/* check whether this flow is registered */
> +	for (i = 0; i < MAX_FLOWS; i++) {
> +		if (map[i].fid == fid) {
> +			flowid = i;
> +			break;
> +		}
> +	}
> +	/* exit if flow is not registered */
> +	if (flowid < 0) {
> +		printk("netem: Invalid FID received. Killing process.\n");
> +		return -EINVAL;
> +	}
> +
> +	checkbuf = map[flowid].sched_data->flowbuffer;
> +	if (checkbuf == NULL) {
> +		printk("netem: no flow registered");
> +		return -ENOBUFS;
> +	}
> +
> +	/* check if flowbuffer has empty buffer and copy data into it */
> +	if (checkbuf->buffer1_empty != NULL) {
> +		memcpy(checkbuf->buffer1, p, DATA_PACKAGE);
> +		checkbuf->buffer1_empty = NULL;
> +		checkbuf->validdataB1 = validData;
> +		map[flowid].sched_data->statistic->buffer1_reloads++;
> +
> +	} else if (checkbuf->buffer2_empty != NULL) {
> +		memcpy(checkbuf->buffer2, p, DATA_PACKAGE);
> +		checkbuf->buffer2_empty = NULL;
> +		checkbuf->validdataB2 = validData;
> +		map[flowid].sched_data->statistic->buffer2_reloads++;
> +
> +	} else {
> +		printk("netem: flow %d: no empty buffer. data loss.\n", flowid);
> +		map[flowid].sched_data->statistic->noemptybuffer++;
> +	}
> +
> +	if (validData) {
> +		/* on initialization both buffers need data */
> +		if (checkbuf->buffer2_empty != NULL) {
> +			return DATA_PACKAGE_ID;
> +		}
> +		/* wait until new data is needed */
> +		wait_event(map[flowid].sched_data->my_event,
> +			   map[flowid].sched_data->newdataneeded);
> +		map[flowid].sched_data->newdataneeded = 0;
> +
> +	}
> +
> +	if (map[flowid].sched_data->tcnstop) {
> +		return -ECANCELED;
> +	}
> +
> +	return DATA_PACKAGE_ID;
> +
> +}
> +
> +static void tcn_flow_release(struct config_item *item)
> +{
> +	kfree(to_tcn_flow(item));
> +
> +}
> +
> +static struct configfs_item_operations tcn_flow_item_ops = {
> +	.release = tcn_flow_release,
> +	.store_attribute = tcn_flow_attr_store,
> +};
> +
> +static struct config_item_type tcn_flow_type = {
> +	.ct_item_ops = &tcn_flow_item_ops,
> +	.ct_attrs = tcn_flow_attrs,
> +	.ct_owner = THIS_MODULE,
> +};
> +
> +static struct config_item * tcn_make_item(struct config_group *group,
> +						     const char *name)
> +{
> +	struct tcn_flow *tcn_flow;
> +
> +	tcn_flow = kmalloc(sizeof(struct tcn_flow), GFP_KERNEL);
> +	if (!tcn_flow)
> +		return NULL;
> +
> +	memset(tcn_flow, 0, sizeof(struct tcn_flow));
> +
> +	config_item_init_type_name(&tcn_flow->item, name,
> +				   &tcn_flow_type);
> +	return &tcn_flow->item;
> +}
> +
> +static struct configfs_group_operations tcn_group_ops = {
> +	.make_item = tcn_make_item,
> +};
> +
> +static struct config_item_type tcn_type = {
> +	.ct_group_ops = &tcn_group_ops,
> +	.ct_owner = THIS_MODULE,
> +};
> +
> +static struct configfs_subsystem tcn_subsys = {
> +	.su_group = {
> +		     .cg_item = {
> +				 .ci_namebuf = "tcn",
> +				 .ci_type = &tcn_type,
> +				 },
> +		     },
> +};
> +
> +static __init int configfs_init(void)
> +{
> +	int ret;
> +	struct configfs_subsystem *subsys = &tcn_subsys;
> +
> +	config_group_init(&subsys->su_group);
> +	init_MUTEX(&subsys->su_sem);
> +	ret = configfs_register_subsystem(subsys);
> +	if (ret) {
> +		printk(KERN_ERR "Error %d while registering subsystem %s\n",
> +		       ret, subsys->su_group.cg_item.ci_namebuf);
> +		configfs_unregister_subsystem(&tcn_subsys);
> +	}
> +	return ret;
> +}
> +
> +static void configfs_exit(void)
> +{
> +	configfs_unregister_subsystem(&tcn_subsys);
> +}
> +
>  static struct Qdisc_class_ops netem_class_ops = {
>  	.graft		=	netem_graft,
>  	.leaf		=	netem_leaf,
> @@ -740,11 +1180,17 @@ static struct Qdisc_ops netem_qdisc_ops 
>  
>  static int __init netem_module_init(void)
>  {
> +	int err;
> +
>  	pr_info("netem: version " VERSION "\n");
> +	err = configfs_init();
> +	if (err)
> +		return err;
>  	return register_qdisc(&netem_qdisc_ops);
>  }
>  static void __exit netem_module_exit(void)
>  {
> +	configfs_exit();
>  	unregister_qdisc(&netem_qdisc_ops);
>  }
>  module_init(netem_module_init)
>   

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Stephen Hemminger]

On Tue, 26 Sep 2006 22:17:57 +0200
Rainer Baumann <baumann@tik.ee.ethz.ch> wrote:

> Hi Stephens
> 
> We merged your changes into our patch
> http://tcn.hypert.net/tcn_kernel_2_6_18.patch
> Please let us know if we should do further adoptions to our
> implementation and/or resubmit the adapted patch.
> 
> Cheers+thanx,
> Rainer

I'll test it out, and send off to Dave for 2.6.20, 2.6.19 is so in
flux right now that adding more seems not like a good idea.

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[David Miller]

From: Stephen Hemminger <shemminger@osdl.org>
Date: Tue, 26 Sep 2006 13:45:31 -0700

> I'll test it out, and send off to Dave for 2.6.20, 2.6.19 is so in
> flux right now that adding more seems not like a good idea.

I'm willing to accept anything reasonable until approximately
this weekend.

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Rainer Baumann]

Hi Stephens

I just wanted to ask you if everything went right with TCN and we will
find it in 2.6.20 as you wrote two months ago.

Cheers
Rainer

Stephen Hemminger wrote:
> On Tue, 26 Sep 2006 22:17:57 +0200
> Rainer Baumann <baumann@tik.ee.ethz.ch> wrote:
>
>   
>> Hi Stephens
>>
>> We merged your changes into our patch
>> http://tcn.hypert.net/tcn_kernel_2_6_18.patch
>> Please let us know if we should do further adoptions to our
>> implementation and/or resubmit the adapted patch.
>>
>> Cheers+thanx,
>> Rainer
>>     
>
> I'll test it out, and send off to Dave for 2.6.20, 2.6.19 is so in
> flux right now that adding more seems not like a good idea.
>
>
>   

Re: [PATCH 2.6.17.13 2/2] LARTC: trace control for netem: kernelspace

[Stephen Hemminger]

On Sat, 09 Dec 2006 10:17:55 +0100
Rainer Baumann <baumann@tik.ee.ethz.ch> wrote:

> Hi Stephens
> 
> I just wanted to ask you if everything went right with TCN and we will
> find it in 2.6.20 as you wrote two months ago.
> 
> Cheers
> Rainer
> 
> Stephen Hemminger wrote:
> > On Tue, 26 Sep 2006 22:17:57 +0200
> > Rainer Baumann <baumann@tik.ee.ethz.ch> wrote:
> >
> >   
> >> Hi Stephens
> >>
> >> We merged your changes into our patch
> >> http://tcn.hypert.net/tcn_kernel_2_6_18.patch
> >> Please let us know if we should do further adoptions to our
> >> implementation and/or resubmit the adapted patch.
> >>
> >> Cheers+thanx,
> >> Rainer
> >>     
> >
> > I'll test it out, and send off to Dave for 2.6.20, 2.6.19 is so in
> > flux right now that adding more seems not like a good idea.
> >
> >
> >   
> 
> -
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

If I get a cleaned up version to test, I have some time to check it
before 2.6.20

TCN im Kern

[Rainer Baumann]

Hi Stephen

In the last two weeks i've got 13 request, in which release the trace
extension TCN for netem will be included. Did you already found time to
integrate it?

Cheers
Rainer

Re: TCN im Kern

[Stephen Hemminger]

On Sat, 20 Jan 2007 10:05:02 +0100
Rainer Baumann <baumann@tik.ee.ethz.ch> wrote:

> Hi Stephen
> 
> In the last two weeks i've got 13 request, in which release the trace
> extension TCN for netem will be included. Did you already found time to
> integrate it?
> 
> Cheers
> Rainer

When I get back from London, early next week