static int
prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct Qdisc *qdisc;
int ret;
qdisc = prio_classify(skb, sch, &ret);
#ifdef CONFIG_NET_CLS_ACT
if (qdisc == NULL) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
kfree_skb(skb);
return ret;
}
#endif
ret = qdisc_enqueue(skb, qdisc);
if (ret == NET_XMIT_SUCCESS) {
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
return ret;
}
static int
prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
{
unsigned int len = qdisc_pkt_len(skb);
struct Qdisc *qdisc;
int ret;
qdisc = prio_classify(skb, sch, &ret);
#ifdef CONFIG_NET_CLS_ACT
if (qdisc == NULL) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
__qdisc_drop(skb, to_free);
return ret;
}
#endif
ret = qdisc_enqueue(skb, qdisc, to_free);
if (ret == NET_XMIT_SUCCESS) {
sch->qstats.backlog += len;
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
return ret;
}
static int wfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct wfq_class *cl = NULL;
unsigned int len = skb_size(skb);
struct wfq_sched_data *q = qdisc_priv(sch);
int ret, weight;
cl = wfq_classify(skb, sch);
/* No appropriate queue or the switch buffer is overfilled */
if (unlikely(!cl) || wfq_buffer_overfill(len, cl, q))
{
qdisc_qstats_drop(sch);
qdisc_qstats_drop(cl->qdisc);
kfree_skb(skb);
return NET_XMIT_DROP;
}
ret = qdisc_enqueue(skb, cl->qdisc);
if (unlikely(ret != NET_XMIT_SUCCESS))
{
if (likely(net_xmit_drop_count(ret)))
{
qdisc_qstats_drop(sch);
qdisc_qstats_drop(cl->qdisc);
}
return ret;
}
/* If the queue is empty, calculate its head finish time */
if (cl->qdisc->q.qlen == 1)
{
weight = wfq_queue_weight[cl->id];
/* We only change the priority when the queue is empty */
cl->prio = (u8)wfq_queue_prio[cl->id];
if (likely(weight > 0))
{
cl->head_fin_time = div_u64((u64)len, (u32)weight) +
q->virtual_time[cl->prio];
q->virtual_time[cl->prio] = cl->head_fin_time;
}
}
/* Update queue sizes */
sch->q.qlen++;
q->sum_len_bytes += len;
cl->len_bytes += len;
q->prio_len_bytes[cl->prio] += len;
/* sojourn time based ECN marking: TCN and CoDel */
if (wfq_ecn_scheme == wfq_tcn || wfq_ecn_scheme == wfq_codel)
skb->tstamp = ktime_get();
/* enqueue queue length based ECN marking */
else if (wfq_enable_dequeue_ecn == wfq_disable)
wfq_qlen_marking(skb, q, cl);
return ret;
}
static void drop_func(struct sk_buff *skb, void *ctx)
{
struct Qdisc *sch = ctx;
kfree_skb(skb);
qdisc_qstats_drop(sch);
}
static unsigned int sfq_drop(struct Qdisc *sch)
{
struct sfq_sched_data *q = qdisc_priv(sch);
sfq_index x, d = q->cur_depth;
struct sk_buff *skb;
unsigned int len;
struct sfq_slot *slot;
/* Queue is full! Find the longest slot and drop tail packet from it */
if (d > 1) {
x = q->dep[d].next;
slot = &q->slots[x];
drop:
skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot);
len = qdisc_pkt_len(skb);
slot->backlog -= len;
sfq_dec(q, x);
sch->q.qlen--;
qdisc_qstats_drop(sch);
qdisc_qstats_backlog_dec(sch, skb);
kfree_skb(skb);
return len;
}
if (d == 1) {
/* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */
x = q->tail->next;
slot = &q->slots[x];
q->tail->next = slot->next;
q->ht[slot->hash] = SFQ_EMPTY_SLOT;
goto drop;
}
return 0;
}
static unsigned int fq_codel_drop(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
unsigned int maxbacklog = 0, idx = 0, i, len;
struct fq_codel_flow *flow;
/* Queue is full! Find the fat flow and drop packet from it.
* This might sound expensive, but with 1024 flows, we scan
* 4KB of memory, and we dont need to handle a complex tree
* in fast path (packet queue/enqueue) with many cache misses.
*/
for (i = 0; i < q->flows_cnt; i++) {
if (q->backlogs[i] > maxbacklog) {
maxbacklog = q->backlogs[i];
idx = i;
}
}
flow = &q->flows[idx];
skb = dequeue_head(flow);
len = qdisc_pkt_len(skb);
q->backlogs[idx] -= len;
kfree_skb(skb);
sch->q.qlen--;
qdisc_qstats_drop(sch);
qdisc_qstats_backlog_dec(sch, skb);
flow->dropped++;
return idx;
}
/* GSO packet is too big, segment it so that tbf can transmit
* each segment in time
*/
static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct tbf_sched_data *q = qdisc_priv(sch);
struct sk_buff *segs, *nskb;
netdev_features_t features = netif_skb_features(skb);
unsigned int len = 0, prev_len = qdisc_pkt_len(skb);
int ret, nb;
segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
if (IS_ERR_OR_NULL(segs))
return qdisc_drop(skb, sch, to_free);
nb = 0;
while (segs) {
nskb = segs->next;
skb_mark_not_on_list(segs);
qdisc_skb_cb(segs)->pkt_len = segs->len;
len += segs->len;
ret = qdisc_enqueue(segs, q->qdisc, to_free);
if (ret != NET_XMIT_SUCCESS) {
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
} else {
nb++;
}
segs = nskb;
}
sch->q.qlen += nb;
if (nb > 1)
qdisc_tree_reduce_backlog(sch, 1 - nb, prev_len - len);
consume_skb(skb);
return nb > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
}
static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct ingress_qdisc_data *p = qdisc_priv(sch);
struct tcf_result res;
struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
int result;
result = tc_classify(skb, fl, &res);
qdisc_bstats_update(sch, skb);
switch (result) {
case TC_ACT_SHOT:
result = TC_ACT_SHOT;
qdisc_qstats_drop(sch);
break;
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
result = TC_ACT_STOLEN;
break;
case TC_ACT_RECLASSIFY:
case TC_ACT_OK:
skb->tc_index = TC_H_MIN(res.classid);
default:
result = TC_ACT_OK;
break;
}
return result;
}
static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
if (likely(skb_queue_len(&sch->q) < sch->limit))
return qdisc_enqueue_tail(skb, sch);
/* queue full, remove one skb to fulfill the limit */
__qdisc_queue_drop_head(sch, &sch->q);
qdisc_qstats_drop(sch);
qdisc_enqueue_tail(skb, sch);
return NET_XMIT_CN;
}
static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
unsigned int prev_backlog;
if (likely(sch->q.qlen < sch->limit))
return qdisc_enqueue_tail(skb, sch);
prev_backlog = sch->qstats.backlog;
/* queue full, remove one skb to fulfill the limit */
__qdisc_queue_drop_head(sch, &sch->q, to_free);
qdisc_qstats_drop(sch);
qdisc_enqueue_tail(skb, sch);
qdisc_tree_reduce_backlog(sch, 0, prev_backlog - sch->qstats.backlog);
return NET_XMIT_CN;
}
static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
unsigned int idx;
struct fq_codel_flow *flow;
int uninitialized_var(ret);
idx = fq_codel_classify(skb, sch, &ret);
if (idx == 0) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
kfree_skb(skb);
return ret;
}
idx--;
if (sch->q.qlen > 128)
skb = skb_reduce_truesize(skb);
codel_set_enqueue_time(skb);
flow = &q->flows[idx];
flow_queue_add(flow, skb);
q->backlogs[idx] += qdisc_pkt_len(skb);
qdisc_qstats_backlog_inc(sch, skb);
if (list_empty(&flow->flowchain)) {
list_add_tail(&flow->flowchain, &q->new_flows);
q->new_flow_count++;
flow->deficit = q->quantum;
flow->dropped = 0;
}
if (++sch->q.qlen <= sch->limit)
return NET_XMIT_SUCCESS;
q->drop_overlimit++;
/* Return Congestion Notification only if we dropped a packet
* from this flow.
*/
if (fq_codel_drop(sch) == idx)
return NET_XMIT_CN;
/* As we dropped a packet, better let upper stack know this */
qdisc_tree_decrease_qlen(sch, 1);
return NET_XMIT_SUCCESS;
}
static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct tbf_sched_data *q = qdisc_priv(sch);
int ret;
if (qdisc_pkt_len(skb) > q->max_size) {
if (skb_is_gso(skb) && skb_gso_mac_seglen(skb) <= q->max_size)
return tbf_segment(skb, sch, to_free);
return qdisc_drop(skb, sch, to_free);
}
ret = qdisc_enqueue(skb, q->qdisc, to_free);
if (ret != NET_XMIT_SUCCESS) {
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
return ret;
}
qdisc_qstats_backlog_inc(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
unsigned int idx, prev_backlog, prev_qlen;
struct fq_codel_flow *flow;
int uninitialized_var(ret);
unsigned int pkt_len;
bool memory_limited;
idx = fq_codel_classify(skb, sch, &ret);
if (idx == 0) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
__qdisc_drop(skb, to_free);
return ret;
}
idx--;
codel_set_enqueue_time(skb);
flow = &q->flows[idx];
flow_queue_add(flow, skb);
q->backlogs[idx] += qdisc_pkt_len(skb);
qdisc_qstats_backlog_inc(sch, skb);
if (list_empty(&flow->flowchain)) {
list_add_tail(&flow->flowchain, &q->new_flows);
q->new_flow_count++;
flow->deficit = q->quantum;
flow->dropped = 0;
}
get_codel_cb(skb)->mem_usage = skb->truesize;
q->memory_usage += get_codel_cb(skb)->mem_usage;
memory_limited = q->memory_usage > q->memory_limit;
if (++sch->q.qlen <= sch->limit && !memory_limited)
return NET_XMIT_SUCCESS;
prev_backlog = sch->qstats.backlog;
prev_qlen = sch->q.qlen;
/* save this packet length as it might be dropped by fq_codel_drop() */
pkt_len = qdisc_pkt_len(skb);
/* fq_codel_drop() is quite expensive, as it performs a linear search
* in q->backlogs[] to find a fat flow.
* So instead of dropping a single packet, drop half of its backlog
* with a 64 packets limit to not add a too big cpu spike here.
*/
ret = fq_codel_drop(sch, q->drop_batch_size, to_free);
prev_qlen -= sch->q.qlen;
prev_backlog -= sch->qstats.backlog;
q->drop_overlimit += prev_qlen;
if (memory_limited)
q->drop_overmemory += prev_qlen;
/* As we dropped packet(s), better let upper stack know this.
* If we dropped a packet for this flow, return NET_XMIT_CN,
* but in this case, our parents wont increase their backlogs.
*/
if (ret == idx) {
qdisc_tree_reduce_backlog(sch, prev_qlen - 1,
prev_backlog - pkt_len);
return NET_XMIT_CN;
}
qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog);
return NET_XMIT_SUCCESS;
}
static int
sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
{
struct sfq_sched_data *q = qdisc_priv(sch);
unsigned int hash, dropped;
sfq_index x, qlen;
struct sfq_slot *slot;
int uninitialized_var(ret);
struct sk_buff *head;
int delta;
hash = sfq_classify(skb, sch, &ret);
if (hash == 0) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
kfree_skb(skb);
return ret;
}
hash--;
x = q->ht[hash];
slot = &q->slots[x];
if (x == SFQ_EMPTY_SLOT) {
x = q->dep[0].next; /* get a free slot */
if (x >= SFQ_MAX_FLOWS)
return qdisc_drop(skb, sch, to_free);
q->ht[hash] = x;
slot = &q->slots[x];
slot->hash = hash;
slot->backlog = 0; /* should already be 0 anyway... */
red_set_vars(&slot->vars);
goto enqueue;
}
if (q->red_parms) {
slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms,
&slot->vars,
slot->backlog);
switch (red_action(q->red_parms,
&slot->vars,
slot->vars.qavg)) {
case RED_DONT_MARK:
break;
case RED_PROB_MARK:
qdisc_qstats_overlimit(sch);
if (sfq_prob_mark(q)) {
/* We know we have at least one packet in queue */
if (sfq_headdrop(q) &&
INET_ECN_set_ce(slot->skblist_next)) {
q->stats.prob_mark_head++;
break;
}
if (INET_ECN_set_ce(skb)) {
q->stats.prob_mark++;
break;
}
}
q->stats.prob_drop++;
goto congestion_drop;
case RED_HARD_MARK:
qdisc_qstats_overlimit(sch);
if (sfq_hard_mark(q)) {
/* We know we have at least one packet in queue */
if (sfq_headdrop(q) &&
INET_ECN_set_ce(slot->skblist_next)) {
q->stats.forced_mark_head++;
break;
}
if (INET_ECN_set_ce(skb)) {
q->stats.forced_mark++;
break;
}
}
q->stats.forced_drop++;
goto congestion_drop;
}
}
if (slot->qlen >= q->maxdepth) {
congestion_drop:
if (!sfq_headdrop(q))
return qdisc_drop(skb, sch, to_free);
/* We know we have at least one packet in queue */
head = slot_dequeue_head(slot);
delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb);
sch->qstats.backlog -= delta;
slot->backlog -= delta;
qdisc_drop(head, sch, to_free);
slot_queue_add(slot, skb);
return NET_XMIT_CN;
}
enqueue:
qdisc_qstats_backlog_inc(sch, skb);
slot->backlog += qdisc_pkt_len(skb);
slot_queue_add(slot, skb);
sfq_inc(q, x);
if (slot->qlen == 1) { /* The flow is new */
if (q->tail == NULL) { /* It is the first flow */
slot->next = x;
} else {
slot->next = q->tail->next;
q->tail->next = x;
}
/* We put this flow at the end of our flow list.
* This might sound unfair for a new flow to wait after old ones,
* but we could endup servicing new flows only, and freeze old ones.
*/
q->tail = slot;
/* We could use a bigger initial quantum for new flows */
slot->allot = q->scaled_quantum;
}
if (++sch->q.qlen <= q->limit)
return NET_XMIT_SUCCESS;
qlen = slot->qlen;
dropped = sfq_drop(sch);
/* Return Congestion Notification only if we dropped a packet
* from this flow.
*/
if (qlen != slot->qlen)
return NET_XMIT_CN;
/* As we dropped a packet, better let upper stack know this */
qdisc_tree_reduce_backlog(sch, 1, dropped);
return NET_XMIT_SUCCESS;
}
static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
struct choke_sched_data *q = qdisc_priv(sch);
const struct red_parms *p = &q->parms;
if (rcu_access_pointer(q->filter_list)) {
/* If using external classifiers, get result and record it. */
if (!choke_classify(skb, sch, &ret))
goto other_drop; /* Packet was eaten by filter */
}
choke_skb_cb(skb)->keys_valid = 0;
/* Compute average queue usage (see RED) */
q->vars.qavg = red_calc_qavg(p, &q->vars, sch->q.qlen);
if (red_is_idling(&q->vars))
red_end_of_idle_period(&q->vars);
/* Is queue small? */
if (q->vars.qavg <= p->qth_min)
q->vars.qcount = -1;
else {
unsigned int idx;
/* Draw a packet at random from queue and compare flow */
if (choke_match_random(q, skb, &idx)) {
q->stats.matched++;
choke_drop_by_idx(sch, idx);
goto congestion_drop;
}
/* Queue is large, always mark/drop */
if (q->vars.qavg > p->qth_max) {
q->vars.qcount = -1;
qdisc_qstats_overlimit(sch);
if (use_harddrop(q) || !use_ecn(q) ||
!INET_ECN_set_ce(skb)) {
q->stats.forced_drop++;
goto congestion_drop;
}
q->stats.forced_mark++;
} else if (++q->vars.qcount) {
if (red_mark_probability(p, &q->vars, q->vars.qavg)) {
q->vars.qcount = 0;
q->vars.qR = red_random(p);
qdisc_qstats_overlimit(sch);
if (!use_ecn(q) || !INET_ECN_set_ce(skb)) {
q->stats.prob_drop++;
goto congestion_drop;
}
q->stats.prob_mark++;
}
} else
q->vars.qR = red_random(p);
}
/* Admit new packet */
if (sch->q.qlen < q->limit) {
q->tab[q->tail] = skb;
q->tail = (q->tail + 1) & q->tab_mask;
++sch->q.qlen;
qdisc_qstats_backlog_inc(sch, skb);
return NET_XMIT_SUCCESS;
}
q->stats.pdrop++;
return qdisc_drop(skb, sch);
congestion_drop:
qdisc_drop(skb, sch);
return NET_XMIT_CN;
other_drop:
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
kfree_skb(skb);
return ret;
}
