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linux-next/net/core/gen_stats.c
Eric Dumazet b33e699fe4 net_sched: add TCA_STATS_PKT64 attribute
Now the kernel uses 64bit packet counters in scheduler layer,
we want to export these counters to user space.

Instead risking breaking user space by adding fields
to struct gnet_stats_basic, add a new TCA_STATS_PKT64.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05 18:20:55 -08:00

434 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/core/gen_stats.c
*
* Authors: Thomas Graf <tgraf@suug.ch>
* Jamal Hadi Salim
* Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* See Documentation/networking/gen_stats.txt
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/socket.h>
#include <linux/rtnetlink.h>
#include <linux/gen_stats.h>
#include <net/netlink.h>
#include <net/gen_stats.h>
static inline int
gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
{
if (nla_put_64bit(d->skb, type, size, buf, padattr))
goto nla_put_failure;
return 0;
nla_put_failure:
if (d->lock)
spin_unlock_bh(d->lock);
kfree(d->xstats);
d->xstats = NULL;
d->xstats_len = 0;
return -1;
}
/**
* gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
* @skb: socket buffer to put statistics TLVs into
* @type: TLV type for top level statistic TLV
* @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
* @xstats_type: TLV type for backward compatibility xstats TLV
* @lock: statistics lock
* @d: dumping handle
* @padattr: padding attribute
*
* Initializes the dumping handle, grabs the statistic lock and appends
* an empty TLV header to the socket buffer for use a container for all
* other statistic TLVS.
*
* The dumping handle is marked to be in backward compatibility mode telling
* all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
*
* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
int xstats_type, spinlock_t *lock,
struct gnet_dump *d, int padattr)
__acquires(lock)
{
memset(d, 0, sizeof(*d));
if (type)
d->tail = (struct nlattr *)skb_tail_pointer(skb);
d->skb = skb;
d->compat_tc_stats = tc_stats_type;
d->compat_xstats = xstats_type;
d->padattr = padattr;
if (lock) {
d->lock = lock;
spin_lock_bh(lock);
}
if (d->tail) {
int ret = gnet_stats_copy(d, type, NULL, 0, padattr);
/* The initial attribute added in gnet_stats_copy() may be
* preceded by a padding attribute, in which case d->tail will
* end up pointing at the padding instead of the real attribute.
* Fix this so gnet_stats_finish_copy() adjusts the length of
* the right attribute.
*/
if (ret == 0 && d->tail->nla_type == padattr)
d->tail = (struct nlattr *)((char *)d->tail +
NLA_ALIGN(d->tail->nla_len));
return ret;
}
return 0;
}
EXPORT_SYMBOL(gnet_stats_start_copy_compat);
/**
* gnet_stats_start_copy - start dumping procedure in compatibility mode
* @skb: socket buffer to put statistics TLVs into
* @type: TLV type for top level statistic TLV
* @lock: statistics lock
* @d: dumping handle
* @padattr: padding attribute
*
* Initializes the dumping handle, grabs the statistic lock and appends
* an empty TLV header to the socket buffer for use a container for all
* other statistic TLVS.
*
* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
struct gnet_dump *d, int padattr)
{
return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
}
EXPORT_SYMBOL(gnet_stats_start_copy);
static void
__gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_basic_cpu __percpu *cpu)
{
int i;
for_each_possible_cpu(i) {
struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
unsigned int start;
u64 bytes, packets;
do {
start = u64_stats_fetch_begin_irq(&bcpu->syncp);
bytes = bcpu->bstats.bytes;
packets = bcpu->bstats.packets;
} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
bstats->bytes += bytes;
bstats->packets += packets;
}
}
void
__gnet_stats_copy_basic(const seqcount_t *running,
struct gnet_stats_basic_packed *bstats,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b)
{
unsigned int seq;
if (cpu) {
__gnet_stats_copy_basic_cpu(bstats, cpu);
return;
}
do {
if (running)
seq = read_seqcount_begin(running);
bstats->bytes = b->bytes;
bstats->packets = b->packets;
} while (running && read_seqcount_retry(running, seq));
}
EXPORT_SYMBOL(__gnet_stats_copy_basic);
static int
___gnet_stats_copy_basic(const seqcount_t *running,
struct gnet_dump *d,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b,
int type)
{
struct gnet_stats_basic_packed bstats = {0};
__gnet_stats_copy_basic(running, &bstats, cpu, b);
if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
d->tc_stats.bytes = bstats.bytes;
d->tc_stats.packets = bstats.packets;
}
if (d->tail) {
struct gnet_stats_basic sb;
int res;
memset(&sb, 0, sizeof(sb));
sb.bytes = bstats.bytes;
sb.packets = bstats.packets;
res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
if (res < 0 || sb.packets == bstats.packets)
return res;
/* emit 64bit stats only if needed */
return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
sizeof(bstats.packets), TCA_STATS_PAD);
}
return 0;
}
/**
* gnet_stats_copy_basic - copy basic statistics into statistic TLV
* @running: seqcount_t pointer
* @d: dumping handle
* @cpu: copy statistic per cpu
* @b: basic statistics
*
* Appends the basic statistics to the top level TLV created by
* gnet_stats_start_copy().
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_copy_basic(const seqcount_t *running,
struct gnet_dump *d,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b)
{
return ___gnet_stats_copy_basic(running, d, cpu, b,
TCA_STATS_BASIC);
}
EXPORT_SYMBOL(gnet_stats_copy_basic);
/**
* gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
* @running: seqcount_t pointer
* @d: dumping handle
* @cpu: copy statistic per cpu
* @b: basic statistics
*
* Appends the basic statistics to the top level TLV created by
* gnet_stats_start_copy().
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_copy_basic_hw(const seqcount_t *running,
struct gnet_dump *d,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b)
{
return ___gnet_stats_copy_basic(running, d, cpu, b,
TCA_STATS_BASIC_HW);
}
EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
/**
* gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
* @d: dumping handle
* @rate_est: rate estimator
*
* Appends the rate estimator statistics to the top level TLV created by
* gnet_stats_start_copy().
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_copy_rate_est(struct gnet_dump *d,
struct net_rate_estimator __rcu **rate_est)
{
struct gnet_stats_rate_est64 sample;
struct gnet_stats_rate_est est;
int res;
if (!gen_estimator_read(rate_est, &sample))
return 0;
est.bps = min_t(u64, UINT_MAX, sample.bps);
/* we have some time before reaching 2^32 packets per second */
est.pps = sample.pps;
if (d->compat_tc_stats) {
d->tc_stats.bps = est.bps;
d->tc_stats.pps = est.pps;
}
if (d->tail) {
res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
TCA_STATS_PAD);
if (res < 0 || est.bps == sample.bps)
return res;
/* emit 64bit stats only if needed */
return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
sizeof(sample), TCA_STATS_PAD);
}
return 0;
}
EXPORT_SYMBOL(gnet_stats_copy_rate_est);
static void
__gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
const struct gnet_stats_queue __percpu *q)
{
int i;
for_each_possible_cpu(i) {
const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
qstats->qlen = 0;
qstats->backlog += qcpu->backlog;
qstats->drops += qcpu->drops;
qstats->requeues += qcpu->requeues;
qstats->overlimits += qcpu->overlimits;
}
}
void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
const struct gnet_stats_queue __percpu *cpu,
const struct gnet_stats_queue *q,
__u32 qlen)
{
if (cpu) {
__gnet_stats_copy_queue_cpu(qstats, cpu);
} else {
qstats->qlen = q->qlen;
qstats->backlog = q->backlog;
qstats->drops = q->drops;
qstats->requeues = q->requeues;
qstats->overlimits = q->overlimits;
}
qstats->qlen = qlen;
}
EXPORT_SYMBOL(__gnet_stats_copy_queue);
/**
* gnet_stats_copy_queue - copy queue statistics into statistics TLV
* @d: dumping handle
* @cpu_q: per cpu queue statistics
* @q: queue statistics
* @qlen: queue length statistics
*
* Appends the queue statistics to the top level TLV created by
* gnet_stats_start_copy(). Using per cpu queue statistics if
* they are available.
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_copy_queue(struct gnet_dump *d,
struct gnet_stats_queue __percpu *cpu_q,
struct gnet_stats_queue *q, __u32 qlen)
{
struct gnet_stats_queue qstats = {0};
__gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
if (d->compat_tc_stats) {
d->tc_stats.drops = qstats.drops;
d->tc_stats.qlen = qstats.qlen;
d->tc_stats.backlog = qstats.backlog;
d->tc_stats.overlimits = qstats.overlimits;
}
if (d->tail)
return gnet_stats_copy(d, TCA_STATS_QUEUE,
&qstats, sizeof(qstats),
TCA_STATS_PAD);
return 0;
}
EXPORT_SYMBOL(gnet_stats_copy_queue);
/**
* gnet_stats_copy_app - copy application specific statistics into statistics TLV
* @d: dumping handle
* @st: application specific statistics data
* @len: length of data
*
* Appends the application specific statistics to the top level TLV created by
* gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
* handle is in backward compatibility mode.
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
{
if (d->compat_xstats) {
d->xstats = kmemdup(st, len, GFP_ATOMIC);
if (!d->xstats)
goto err_out;
d->xstats_len = len;
}
if (d->tail)
return gnet_stats_copy(d, TCA_STATS_APP, st, len,
TCA_STATS_PAD);
return 0;
err_out:
if (d->lock)
spin_unlock_bh(d->lock);
d->xstats_len = 0;
return -1;
}
EXPORT_SYMBOL(gnet_stats_copy_app);
/**
* gnet_stats_finish_copy - finish dumping procedure
* @d: dumping handle
*
* Corrects the length of the top level TLV to include all TLVs added
* by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
* if gnet_stats_start_copy_compat() was used and releases the statistics
* lock.
*
* Returns 0 on success or -1 with the statistic lock released
* if the room in the socket buffer was not sufficient.
*/
int
gnet_stats_finish_copy(struct gnet_dump *d)
{
if (d->tail)
d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
if (d->compat_tc_stats)
if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
sizeof(d->tc_stats), d->padattr) < 0)
return -1;
if (d->compat_xstats && d->xstats) {
if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
d->xstats_len, d->padattr) < 0)
return -1;
}
if (d->lock)
spin_unlock_bh(d->lock);
kfree(d->xstats);
d->xstats = NULL;
d->xstats_len = 0;
return 0;
}
EXPORT_SYMBOL(gnet_stats_finish_copy);