@@ -1210,4 +1210,28 @@ enum {
#define TCA_ETS_MAX (__TCA_ETS_MAX - 1)
+/* DUALPI2 */
+enum {
+ TCA_DUALPI2_UNSPEC,
+ TCA_DUALPI2_LIMIT, /* Packets */
+ TCA_DUALPI2_MEMORY_LIMIT, /* Bytes */
+ TCA_DUALPI2_TARGET, /* us */
+ TCA_DUALPI2_TUPDATE, /* us */
+ TCA_DUALPI2_ALPHA, /* Hz scaled up by 256 */
+ TCA_DUALPI2_BETA, /* HZ scaled up by 256 */
+ TCA_DUALPI2_STEP_THRESH, /* Packets or us */
+ TCA_DUALPI2_STEP_PACKETS, /* Whether STEP_THRESH is in packets */
+ TCA_DUALPI2_MIN_QLEN_STEP, /* Minimum qlen to apply STEP_THRESH */
+ TCA_DUALPI2_COUPLING, /* Coupling factor between queues */
+ TCA_DUALPI2_DROP_OVERLOAD, /* Whether to drop on overload */
+ TCA_DUALPI2_DROP_EARLY, /* Whether to drop on enqueue */
+ TCA_DUALPI2_C_PROTECTION, /* Percentage */
+ TCA_DUALPI2_ECN_MASK, /* L4S queue classification mask */
+ TCA_DUALPI2_SPLIT_GSO, /* Split GSO packets at enqueue */
+ TCA_DUALPI2_PAD,
+ __TCA_DUALPI2_MAX
+};
+
+#define TCA_DUALPI2_MAX (__TCA_DUALPI2_MAX - 1)
+
#endif
new file mode 100644
@@ -0,0 +1,554 @@
+// SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+/* Copyright (C) 2024 Nokia
+ *
+ * Author: Koen De Schepper <koen.de_schepper@nokia-bell-labs.com>
+ * Author: Olga Albisser <olga@albisser.org>
+ * Author: Henrik Steen <henrist@henrist.net>
+ * Author: Olivier Tilmans <olivier.tilmans@nokia.com>
+ * Author: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
+ *
+ * DualPI Improved with a Square (dualpi2):
+ * - Supports congestion controls that comply with the Prague requirements
+ * in RFC9331 (e.g. TCP-Prague)
+ * - Supports coupled dual-queue with PI2 as defined in RFC9332
+ * - Supports ECN L4S-identifier (IP.ECN==0b*1)
+ *
+ * note: Although DCTCP and BBRv3 can use shallow-threshold ECN marks,
+ * they do not meet the 'Prague L4S Requirements' listed in RFC 9331
+ * Section 4, so they can only be used with DualPI2 in a datacenter
+ * context.
+ *
+ * References:
+ * - RFC9332: https://datatracker.ietf.org/doc/html/rfc9332
+ * - De Schepper, Koen, et al. "PI 2: A linearized AQM for both classic and
+ * scalable TCP." in proc. ACM CoNEXT'16, 2016.
+ */
+
+#include <linux/errno.h>
+#include <linux/hrtimer.h>
+#include <linux/if_vlan.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include <net/gso.h>
+#include <net/inet_ecn.h>
+#include <net/pkt_cls.h>
+#include <net/pkt_sched.h>
+
+/* 32b enable to support flows with windows up to ~8.6 * 1e9 packets
+ * i.e., twice the maximal snd_cwnd.
+ * MAX_PROB must be consistent with the RNG in dualpi2_roll().
+ */
+#define MAX_PROB U32_MAX
+
+/* alpha/beta values exchanged over netlink are in units of 256ns */
+#define ALPHA_BETA_SHIFT 8
+
+/* Scaled values of alpha/beta must fit in 32b to avoid overflow in later
+ * computations. Consequently (see and dualpi2_scale_alpha_beta()), their
+ * netlink-provided values can use at most 31b, i.e. be at most (2^23)-1
+ * (~4MHz) as those are given in 1/256th. This enable to tune alpha/beta to
+ * control flows whose maximal RTTs can be in usec up to few secs.
+ */
+#define ALPHA_BETA_MAX ((1U << 31) - 1)
+
+/* Internal alpha/beta are in units of 64ns.
+ * This enables to use all alpha/beta values in the allowed range without loss
+ * of precision due to rounding when scaling them internally, e.g.,
+ * scale_alpha_beta(1) will not round down to 0.
+ */
+#define ALPHA_BETA_GRANULARITY 6
+
+#define ALPHA_BETA_SCALING (ALPHA_BETA_SHIFT - ALPHA_BETA_GRANULARITY)
+
+/* We express the weights (wc, wl) in %, i.e., wc + wl = 100 */
+#define MAX_WC 100
+
+struct dualpi2_sched_data {
+ struct Qdisc *l_queue; /* The L4S Low latency queue (L-queue) */
+ struct Qdisc *sch; /* The Classic queue (C-queue) */
+
+ /* Registered tc filters */
+ struct tcf_proto __rcu *tcf_filters;
+ struct tcf_block *tcf_block;
+
+ /* PI2 parameters */
+ u64 pi2_target; /* Target delay in nanoseconds */
+ u32 pi2_tupdate; /* Timer frequency in nanoseconds */
+ u32 pi2_prob; /* Base PI probability */
+ u32 pi2_alpha; /* Gain factor for the integral rate response */
+ u32 pi2_beta; /* Gain factor for the proportional response */
+ struct hrtimer pi2_timer; /* prob update timer */
+
+ /* Step AQM (L-queue only) parameters */
+ u32 step_thresh; /* Step threshold */
+ bool step_in_packets; /* Whether the step is in packets or time */
+
+ /* C-queue starvation protection */
+ s32 c_protection_credit; /* Credit (sign indicates which queue) */
+ s32 c_protection_init; /* Reset value of the credit */
+ u8 c_protection_wc; /* C-queue weight (between 0 and MAX_WC) */
+ u8 c_protection_wl; /* L-queue weight (MAX_WC - wc) */
+
+ /* General dualQ parameters */
+ u32 memory_limit; /* Memory limit of both queues */
+ u8 coupling_factor;/* Coupling factor (k) between both queues */
+ u8 ecn_mask; /* Mask to match packets into L-queue */
+ u32 min_qlen_step; /* Minimum queue length to apply step thresh */
+ bool drop_early; /* Drop at enqueue instead of dequeue if true */
+ bool drop_overload; /* Drop (1) on overload, or overflow (0) */
+ bool split_gso; /* Split aggregated skb (1) or leave as is */
+
+ /* Statistics */
+ u64 c_head_ts; /* Enqueue timestamp of the C-queue head */
+ u64 l_head_ts; /* Enqueue timestamp of the L-queue head */
+ u64 last_qdelay; /* Q delay val at the last probability update */
+ u32 packets_in_c; /* Enqueue packet counter of the C-queue */
+ u32 packets_in_l; /* Enqueue packet counter of the L-queue */
+ u32 maxq; /* Maximum queue size of the C-queue */
+ u32 ecn_mark; /* ECN mark pkt counter due to PI probability */
+ u32 step_marks; /* ECN mark pkt counter due to step AQM */
+ u32 memory_used; /* Memory used of both queues */
+ u32 max_memory_used;/* Maximum used memory */
+};
+
+static u32 dualpi2_scale_alpha_beta(u32 param)
+{
+ u64 tmp = ((u64)param * MAX_PROB >> ALPHA_BETA_SCALING);
+
+ do_div(tmp, NSEC_PER_SEC);
+ return tmp;
+}
+
+static ktime_t next_pi2_timeout(struct dualpi2_sched_data *q)
+{
+ return ktime_add_ns(ktime_get_ns(), q->pi2_tupdate);
+}
+
+static void dualpi2_reset_c_protection(struct dualpi2_sched_data *q)
+{
+ q->c_protection_credit = q->c_protection_init;
+}
+
+/* This computes the initial credit value and WRR weight for the L queue (wl)
+ * from the weight of the C queue (wc).
+ * If wl > wc, the scheduler will start with the L queue when reset.
+ */
+static void dualpi2_calculate_c_protection(struct Qdisc *sch,
+ struct dualpi2_sched_data *q, u32 wc)
+{
+ q->c_protection_wc = wc;
+ q->c_protection_wl = MAX_WC - wc;
+ q->c_protection_init = (s32)psched_mtu(qdisc_dev(sch)) *
+ ((int)q->c_protection_wc - (int)q->c_protection_wl);
+ dualpi2_reset_c_protection(q);
+}
+
+static s64 __scale_delta(u64 diff)
+{
+ do_div(diff, 1 << ALPHA_BETA_GRANULARITY);
+ return diff;
+}
+
+static void get_queue_delays(struct dualpi2_sched_data *q, u64 *qdelay_c,
+ u64 *qdelay_l)
+{
+ u64 now, qc, ql;
+
+ now = ktime_get_ns();
+ qc = READ_ONCE(q->c_head_ts);
+ ql = READ_ONCE(q->l_head_ts);
+
+ *qdelay_c = qc ? now - qc : 0;
+ *qdelay_l = ql ? now - ql : 0;
+}
+
+static u32 calculate_probability(struct Qdisc *sch)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+ u32 new_prob;
+ u64 qdelay_c;
+ u64 qdelay_l;
+ u64 qdelay;
+ s64 delta;
+
+ get_queue_delays(q, &qdelay_c, &qdelay_l);
+ qdelay = max(qdelay_l, qdelay_c);
+ /* Alpha and beta take at most 32b, i.e, the delay difference would
+ * overflow for queuing delay differences > ~4.2sec.
+ */
+ delta = ((s64)qdelay - q->pi2_target) * q->pi2_alpha;
+ delta += ((s64)qdelay - q->last_qdelay) * q->pi2_beta;
+ if (delta > 0) {
+ new_prob = __scale_delta(delta) + q->pi2_prob;
+ if (new_prob < q->pi2_prob)
+ new_prob = MAX_PROB;
+ } else {
+ new_prob = q->pi2_prob - __scale_delta(~delta + 1);
+ if (new_prob > q->pi2_prob)
+ new_prob = 0;
+ }
+ q->last_qdelay = qdelay;
+ /* If we do not drop on overload, ensure we cap the L4S probability to
+ * 100% to keep window fairness when overflowing.
+ */
+ if (!q->drop_overload)
+ return min_t(u32, new_prob, MAX_PROB / q->coupling_factor);
+ return new_prob;
+}
+
+static u32 get_memory_limit(struct Qdisc *sch, u32 limit)
+{
+ /* Apply rule of thumb, i.e., doubling the packet length,
+ * to further include per packet overhead in memory_limit.
+ */
+ u64 memlim = mul_u32_u32(limit, 2 * psched_mtu(qdisc_dev(sch)));
+
+ if (upper_32_bits(memlim))
+ return 0xffffffff;
+ else
+ return lower_32_bits(memlim);
+}
+
+static enum hrtimer_restart dualpi2_timer(struct hrtimer *timer)
+{
+ struct dualpi2_sched_data *q = from_timer(q, timer, pi2_timer);
+
+ WRITE_ONCE(q->pi2_prob, calculate_probability(q->sch));
+
+ hrtimer_set_expires(&q->pi2_timer, next_pi2_timeout(q));
+ return HRTIMER_RESTART;
+}
+
+static struct netlink_range_validation dualpi2_alpha_beta_range = {
+ .min = 1,
+ .max = ALPHA_BETA_MAX,
+};
+
+static struct netlink_range_validation dualpi2_wc_range = {
+ .min = 0,
+ .max = MAX_WC,
+};
+
+static const struct nla_policy dualpi2_policy[TCA_DUALPI2_MAX + 1] = {
+ [TCA_DUALPI2_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
+ [TCA_DUALPI2_MEMORY_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
+ [TCA_DUALPI2_TARGET] = {.type = NLA_U32},
+ [TCA_DUALPI2_TUPDATE] = NLA_POLICY_MIN(NLA_U32, 1),
+ [TCA_DUALPI2_ALPHA] =
+ NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
+ [TCA_DUALPI2_BETA] =
+ NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
+ [TCA_DUALPI2_STEP_THRESH] = {.type = NLA_U32},
+ [TCA_DUALPI2_STEP_PACKETS] = {.type = NLA_FLAG},
+ [TCA_DUALPI2_MIN_QLEN_STEP] = {.type = NLA_U32},
+ [TCA_DUALPI2_COUPLING] = NLA_POLICY_MIN(NLA_U8, 1),
+ [TCA_DUALPI2_DROP_OVERLOAD] = {.type = NLA_U8},
+ [TCA_DUALPI2_DROP_EARLY] = {.type = NLA_U8},
+ [TCA_DUALPI2_C_PROTECTION] =
+ NLA_POLICY_FULL_RANGE(NLA_U8, &dualpi2_wc_range),
+ [TCA_DUALPI2_ECN_MASK] = {.type = NLA_U8},
+ [TCA_DUALPI2_SPLIT_GSO] = {.type = NLA_U8},
+};
+
+static int dualpi2_change(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[TCA_DUALPI2_MAX + 1];
+ struct dualpi2_sched_data *q;
+ int old_backlog;
+ int old_qlen;
+ int err;
+
+ if (!opt)
+ return -EINVAL;
+ err = nla_parse_nested(tb, TCA_DUALPI2_MAX, opt, dualpi2_policy,
+ extack);
+ if (err < 0)
+ return err;
+
+ q = qdisc_priv(sch);
+ sch_tree_lock(sch);
+
+ if (tb[TCA_DUALPI2_LIMIT]) {
+ u32 limit = nla_get_u32(tb[TCA_DUALPI2_LIMIT]);
+
+ WRITE_ONCE(sch->limit, limit);
+ WRITE_ONCE(q->memory_limit, get_memory_limit(sch, limit));
+ }
+
+ if (tb[TCA_DUALPI2_MEMORY_LIMIT])
+ WRITE_ONCE(q->memory_limit,
+ nla_get_u32(tb[TCA_DUALPI2_MEMORY_LIMIT]));
+
+ if (tb[TCA_DUALPI2_TARGET]) {
+ u64 target = nla_get_u32(tb[TCA_DUALPI2_TARGET]);
+
+ WRITE_ONCE(q->pi2_target, target * NSEC_PER_USEC);
+ }
+
+ if (tb[TCA_DUALPI2_TUPDATE]) {
+ u64 tupdate = nla_get_u32(tb[TCA_DUALPI2_TUPDATE]);
+
+ WRITE_ONCE(q->pi2_tupdate, tupdate * NSEC_PER_USEC);
+ }
+
+ if (tb[TCA_DUALPI2_ALPHA]) {
+ u32 alpha = nla_get_u32(tb[TCA_DUALPI2_ALPHA]);
+
+ WRITE_ONCE(q->pi2_alpha, dualpi2_scale_alpha_beta(alpha));
+ }
+
+ if (tb[TCA_DUALPI2_BETA]) {
+ u32 beta = nla_get_u32(tb[TCA_DUALPI2_BETA]);
+
+ WRITE_ONCE(q->pi2_beta, dualpi2_scale_alpha_beta(beta));
+ }
+
+ if (tb[TCA_DUALPI2_STEP_THRESH]) {
+ u32 step_th = nla_get_u32(tb[TCA_DUALPI2_STEP_THRESH]);
+ bool step_pkt = nla_get_flag(tb[TCA_DUALPI2_STEP_PACKETS]);
+
+ WRITE_ONCE(q->step_in_packets, step_pkt);
+ WRITE_ONCE(q->step_thresh,
+ step_pkt ? step_th : (step_th * NSEC_PER_USEC));
+ }
+
+ if (tb[TCA_DUALPI2_MIN_QLEN_STEP])
+ WRITE_ONCE(q->min_qlen_step,
+ nla_get_u32(tb[TCA_DUALPI2_MIN_QLEN_STEP]));
+
+ if (tb[TCA_DUALPI2_COUPLING]) {
+ u8 coupling = nla_get_u8(tb[TCA_DUALPI2_COUPLING]);
+
+ WRITE_ONCE(q->coupling_factor, coupling);
+ }
+
+ if (tb[TCA_DUALPI2_DROP_OVERLOAD])
+ WRITE_ONCE(q->drop_overload,
+ !!nla_get_u8(tb[TCA_DUALPI2_DROP_OVERLOAD]));
+
+ if (tb[TCA_DUALPI2_DROP_EARLY])
+ WRITE_ONCE(q->drop_early,
+ !!nla_get_u8(tb[TCA_DUALPI2_DROP_EARLY]));
+
+ if (tb[TCA_DUALPI2_C_PROTECTION]) {
+ u8 wc = nla_get_u8(tb[TCA_DUALPI2_C_PROTECTION]);
+
+ dualpi2_calculate_c_protection(sch, q, wc);
+ }
+
+ if (tb[TCA_DUALPI2_ECN_MASK])
+ WRITE_ONCE(q->ecn_mask,
+ nla_get_u8(tb[TCA_DUALPI2_ECN_MASK]));
+
+ if (tb[TCA_DUALPI2_SPLIT_GSO])
+ WRITE_ONCE(q->split_gso,
+ !!nla_get_u8(tb[TCA_DUALPI2_SPLIT_GSO]));
+
+ old_qlen = qdisc_qlen(sch);
+ old_backlog = sch->qstats.backlog;
+ while (qdisc_qlen(sch) > sch->limit ||
+ q->memory_used > q->memory_limit) {
+ struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
+
+ q->memory_used -= skb->truesize;
+ qdisc_qstats_backlog_dec(sch, skb);
+ rtnl_qdisc_drop(skb, sch);
+ }
+ qdisc_tree_reduce_backlog(sch, old_qlen - qdisc_qlen(sch),
+ old_backlog - sch->qstats.backlog);
+
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+/* Default alpha/beta values give a 10dB stability margin with max_rtt=100ms. */
+static void dualpi2_reset_default(struct Qdisc *sch)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+
+ q->sch->limit = 10000; /* Max 125ms at 1Gbps */
+ q->memory_limit = get_memory_limit(sch, q->sch->limit);
+
+ q->pi2_target = 15 * NSEC_PER_MSEC;
+ q->pi2_tupdate = 16 * NSEC_PER_MSEC;
+ q->pi2_alpha = dualpi2_scale_alpha_beta(41); /* ~0.16 Hz * 256 */
+ q->pi2_beta = dualpi2_scale_alpha_beta(819); /* ~3.20 Hz * 256 */
+
+ q->step_thresh = 1 * NSEC_PER_MSEC;
+ q->step_in_packets = false;
+
+ dualpi2_calculate_c_protection(q->sch, q, 10); /* wc=10%, wl=90% */
+
+ q->ecn_mask = INET_ECN_ECT_1;
+ q->min_qlen_step = 0;
+ q->coupling_factor = 2; /* window fairness for equal RTTs */
+ q->drop_overload = true; /* Preserve latency by dropping */
+ q->drop_early = false; /* PI2 drops on dequeue */
+ q->split_gso = true;
+}
+
+static int dualpi2_init(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+ int err;
+
+ q->l_queue = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+ TC_H_MAKE(sch->handle, 1), extack);
+ if (!q->l_queue)
+ return -ENOMEM;
+
+ err = tcf_block_get(&q->tcf_block, &q->tcf_filters, sch, extack);
+ if (err)
+ return err;
+
+ q->sch = sch;
+ dualpi2_reset_default(sch);
+ hrtimer_setup(&q->pi2_timer, dualpi2_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
+
+ if (opt) {
+ err = dualpi2_change(sch, opt, extack);
+
+ if (err)
+ return err;
+ }
+
+ hrtimer_start(&q->pi2_timer, next_pi2_timeout(q),
+ HRTIMER_MODE_ABS_PINNED);
+ return 0;
+}
+
+/* Reset both L-queue and C-queue, internal packet counters, PI probability,
+ * C-queue protection credit, and timestamps, while preserving current
+ * configuration of DUALPI2.
+ */
+static void dualpi2_reset(struct Qdisc *sch)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+
+ qdisc_reset_queue(sch);
+ qdisc_reset_queue(q->l_queue);
+ q->c_head_ts = 0;
+ q->l_head_ts = 0;
+ q->pi2_prob = 0;
+ q->packets_in_c = 0;
+ q->packets_in_l = 0;
+ q->maxq = 0;
+ q->ecn_mark = 0;
+ q->step_marks = 0;
+ q->memory_used = 0;
+ q->max_memory_used = 0;
+ dualpi2_reset_c_protection(q);
+}
+
+static void dualpi2_destroy(struct Qdisc *sch)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+
+ q->pi2_tupdate = 0;
+ hrtimer_cancel(&q->pi2_timer);
+ if (q->l_queue)
+ qdisc_put(q->l_queue);
+ tcf_block_put(q->tcf_block);
+}
+
+static struct Qdisc *dualpi2_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ return NULL;
+}
+
+static unsigned long dualpi2_find(struct Qdisc *sch, u32 classid)
+{
+ return 0;
+}
+
+static unsigned long dualpi2_bind(struct Qdisc *sch, unsigned long parent,
+ u32 classid)
+{
+ return 0;
+}
+
+static void dualpi2_unbind(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static struct tcf_block *dualpi2_tcf_block(struct Qdisc *sch, unsigned long cl,
+ struct netlink_ext_ack *extack)
+{
+ struct dualpi2_sched_data *q = qdisc_priv(sch);
+
+ if (cl)
+ return NULL;
+ return q->tcf_block;
+}
+
+static void dualpi2_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ unsigned int i;
+
+ if (arg->stop)
+ return;
+
+ /* We statically define only 2 queues */
+ for (i = 0; i < 2; i++) {
+ if (arg->count < arg->skip) {
+ arg->count++;
+ continue;
+ }
+ if (arg->fn(sch, i + 1, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+ arg->count++;
+ }
+}
+
+/* Minimal class support to handler tc filters */
+static const struct Qdisc_class_ops dualpi2_class_ops = {
+ .leaf = dualpi2_leaf,
+ .find = dualpi2_find,
+ .tcf_block = dualpi2_tcf_block,
+ .bind_tcf = dualpi2_bind,
+ .unbind_tcf = dualpi2_unbind,
+ .walk = dualpi2_walk,
+};
+
+static struct Qdisc_ops dualpi2_qdisc_ops __read_mostly = {
+ .id = "dualpi2",
+ .cl_ops = &dualpi2_class_ops,
+ .priv_size = sizeof(struct dualpi2_sched_data),
+ .peek = qdisc_peek_dequeued,
+ .init = dualpi2_init,
+ .destroy = dualpi2_destroy,
+ .reset = dualpi2_reset,
+ .change = dualpi2_change,
+ .owner = THIS_MODULE,
+};
+
+static int __init dualpi2_module_init(void)
+{
+ return register_qdisc(&dualpi2_qdisc_ops);
+}
+
+static void __exit dualpi2_module_exit(void)
+{
+ unregister_qdisc(&dualpi2_qdisc_ops);
+}
+
+module_init(dualpi2_module_init);
+module_exit(dualpi2_module_exit);
+
+MODULE_DESCRIPTION("Dual Queue with Proportional Integral controller Improved with a Square (dualpi2) scheduler");
+MODULE_AUTHOR("Koen De Schepper <koen.de_schepper@nokia-bell-labs.com>");
+MODULE_AUTHOR("Olga Albisser <olga@albisser.org>");
+MODULE_AUTHOR("Henrik Steen <henrist@henrist.net>");
+MODULE_AUTHOR("Olivier Tilmans <olivier.tilmans@nokia.com>");
+MODULE_AUTHOR("Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>");
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION("1.0");