Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / net / sched / sch_netem.c
index bb9bf8d..5a4a4d0 100644 (file)
@@ -25,6 +25,8 @@
 
 #include <net/pkt_sched.h>
 
+#define VERSION "1.2"
+
 /*     Network Emulation Queuing algorithm.
        ====================================
 
@@ -63,11 +65,12 @@ struct netem_sched_data {
        u32 jitter;
        u32 duplicate;
        u32 reorder;
+       u32 corrupt;
 
        struct crndstate {
                unsigned long last;
                unsigned long rho;
-       } delay_cor, loss_cor, dup_cor, reorder_cor;
+       } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;
 
        struct disttable {
                u32  size;
@@ -164,7 +167,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        if (count == 0) {
                sch->qstats.drops++;
                kfree_skb(skb);
-               return NET_XMIT_DROP;
+               return NET_XMIT_BYPASS;
        }
 
        /*
@@ -181,14 +184,34 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                q->duplicate = dupsave;
        }
 
+       /*
+        * Randomized packet corruption.
+        * Make copy if needed since we are modifying
+        * 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 (!(skb = skb_unshare(skb, GFP_ATOMIC))
+                   || (skb->ip_summed == CHECKSUM_HW
+                       && skb_checksum_help(skb, 0))) {
+                       sch->qstats.drops++;
+                       return NET_XMIT_DROP;
+               }
+
+               skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8);
+       }
+
        if (q->gap == 0                 /* not doing reordering */
            || 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);
+
                PSCHED_GET_TIME(now);
-               PSCHED_TADD2(now, tabledist(q->latency, q->jitter, 
-                                           &q->delay_cor, q->delay_dist),
-                            cb->time_to_send);
+               PSCHED_TADD2(now, delay, cb->time_to_send);
                ++q->counter;
                ret = q->qdisc->enqueue(skb, q->qdisc);
        } else {
@@ -229,9 +252,9 @@ static int netem_requeue(struct sk_buff *skb, struct Qdisc *sch)
 static unsigned int netem_drop(struct Qdisc* sch)
 {
        struct netem_sched_data *q = qdisc_priv(sch);
-       unsigned int len;
+       unsigned int len = 0;
 
-       if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
+       if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
                sch->q.qlen--;
                sch->qstats.drops++;
        }
@@ -248,24 +271,31 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch)
                const struct netem_skb_cb *cb
                        = (const struct netem_skb_cb *)skb->cb;
                psched_time_t now;
-               long delay;
 
                /* if more time remaining? */
                PSCHED_GET_TIME(now);
-               delay = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
-               pr_debug("netem_run: skb=%p delay=%ld\n", skb, delay);
-               if (delay <= 0) {
+
+               if (PSCHED_TLESS(cb->time_to_send, now)) {
                        pr_debug("netem_dequeue: return skb=%p\n", skb);
                        sch->q.qlen--;
                        sch->flags &= ~TCQ_F_THROTTLED;
                        return skb;
-               }
+               } else {
+                       psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now);
 
-               mod_timer(&q->timer, jiffies + delay);
-               sch->flags |= TCQ_F_THROTTLED;
+                       if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
+                               sch->qstats.drops++;
 
-               if (q->qdisc->ops->requeue(skb, q->qdisc) != 0)
-                       sch->qstats.drops++;
+                               /* After this qlen is confused */
+                               printk(KERN_ERR "netem: queue discpline %s could not requeue\n",
+                                      q->qdisc->ops->id);
+
+                               sch->q.qlen--;
+                       }
+
+                       mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay));
+                       sch->flags |= TCQ_F_THROTTLED;
+               }
        }
 
        return NULL;
@@ -290,11 +320,16 @@ static void netem_reset(struct Qdisc *sch)
        del_timer_sync(&q->timer);
 }
 
+/* Pass size change message down to embedded FIFO */
 static int set_fifo_limit(struct Qdisc *q, int limit)
 {
         struct rtattr *rta;
        int ret = -ENOMEM;
 
+       /* Hack to avoid sending change message to non-FIFO */
+       if (strncmp(q->ops->id + 1, "fifo", 4) != 0)
+               return 0;
+
        rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
        if (rta) {
                rta->rta_type = RTM_NEWQDISC;
@@ -365,6 +400,20 @@ static int get_reorder(struct Qdisc *sch, const struct rtattr *attr)
        return 0;
 }
 
+static int get_corrupt(struct Qdisc *sch, const struct rtattr *attr)
+{
+       struct netem_sched_data *q = qdisc_priv(sch);
+       const struct tc_netem_corrupt *r = RTA_DATA(attr);
+
+       if (RTA_PAYLOAD(attr) != sizeof(*r))
+               return -EINVAL;
+
+       q->corrupt = r->probability;
+       init_crandom(&q->corrupt_cor, r->correlation);
+       return 0;
+}
+
+/* Parse netlink message to set options */
 static int netem_change(struct Qdisc *sch, struct rtattr *opt)
 {
        struct netem_sched_data *q = qdisc_priv(sch);
@@ -415,17 +464,101 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt)
                        if (ret)
                                return ret;
                }
+
                if (tb[TCA_NETEM_REORDER-1]) {
                        ret = get_reorder(sch, tb[TCA_NETEM_REORDER-1]);
                        if (ret)
                                return ret;
                }
+
+               if (tb[TCA_NETEM_CORRUPT-1]) {
+                       ret = get_corrupt(sch, tb[TCA_NETEM_CORRUPT-1]);
+                       if (ret)
+                               return ret;
+               }
        }
 
+       return 0;
+}
+
+/*
+ * Special case version of FIFO queue for use by netem.
+ * It queues in order based on timestamps in skb's
+ */
+struct fifo_sched_data {
+       u32 limit;
+};
+
+static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
+{
+       struct fifo_sched_data *q = qdisc_priv(sch);
+       struct sk_buff_head *list = &sch->q;
+       const struct netem_skb_cb *ncb
+               = (const struct netem_skb_cb *)nskb->cb;
+       struct sk_buff *skb;
+
+       if (likely(skb_queue_len(list) < q->limit)) {
+               skb_queue_reverse_walk(list, skb) {
+                       const struct netem_skb_cb *cb
+                               = (const struct netem_skb_cb *)skb->cb;
+
+                       if (!PSCHED_TLESS(ncb->time_to_send, cb->time_to_send))
+                               break;
+               }
+
+               __skb_queue_after(list, skb, nskb);
+
+               sch->qstats.backlog += nskb->len;
+               sch->bstats.bytes += nskb->len;
+               sch->bstats.packets++;
+
+               return NET_XMIT_SUCCESS;
+       }
+
+       return qdisc_drop(nskb, sch);
+}
+
+static int tfifo_init(struct Qdisc *sch, struct rtattr *opt)
+{
+       struct fifo_sched_data *q = qdisc_priv(sch);
+
+       if (opt) {
+               struct tc_fifo_qopt *ctl = RTA_DATA(opt);
+               if (RTA_PAYLOAD(opt) < sizeof(*ctl))
+                       return -EINVAL;
+
+               q->limit = ctl->limit;
+       } else
+               q->limit = max_t(u32, sch->dev->tx_queue_len, 1);
 
        return 0;
 }
 
+static int tfifo_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+       struct fifo_sched_data *q = qdisc_priv(sch);
+       struct tc_fifo_qopt opt = { .limit = q->limit };
+
+       RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+       return skb->len;
+
+rtattr_failure:
+       return -1;
+}
+
+static struct Qdisc_ops tfifo_qdisc_ops = {
+       .id             =       "tfifo",
+       .priv_size      =       sizeof(struct fifo_sched_data),
+       .enqueue        =       tfifo_enqueue,
+       .dequeue        =       qdisc_dequeue_head,
+       .requeue        =       qdisc_requeue,
+       .drop           =       qdisc_queue_drop,
+       .init           =       tfifo_init,
+       .reset          =       qdisc_reset_queue,
+       .change         =       tfifo_init,
+       .dump           =       tfifo_dump,
+};
+
 static int netem_init(struct Qdisc *sch, struct rtattr *opt)
 {
        struct netem_sched_data *q = qdisc_priv(sch);
@@ -438,7 +571,7 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt)
        q->timer.function = netem_watchdog;
        q->timer.data = (unsigned long) sch;
 
-       q->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
+       q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops);
        if (!q->qdisc) {
                pr_debug("netem: qdisc create failed\n");
                return -ENOMEM;
@@ -469,6 +602,7 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
        struct tc_netem_qopt qopt;
        struct tc_netem_corr cor;
        struct tc_netem_reorder reorder;
+       struct tc_netem_corrupt corrupt;
 
        qopt.latency = q->latency;
        qopt.jitter = q->jitter;
@@ -487,6 +621,10 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
        reorder.correlation = q->reorder_cor.rho;
        RTA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder);
 
+       corrupt.probability = q->corrupt;
+       corrupt.correlation = q->corrupt_cor.rho;
+       RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
+
        rta->rta_len = skb->tail - b;
 
        return skb->len;
@@ -601,6 +739,7 @@ static struct Qdisc_ops netem_qdisc_ops = {
 
 static int __init netem_module_init(void)
 {
+       pr_info("netem: version " VERSION "\n");
        return register_qdisc(&netem_qdisc_ops);
 }
 static void __exit netem_module_exit(void)