linux/drivers/net/netdevsim/psample.c
Ido Schimmel a9b5d871ab netdevsim: Only use sampling truncation length when valid
When the sampling truncation length is invalid (zero), pass the length
of the packet. Without the fix, no payload is reported to user space
when the truncation length is zero.

Fixes: a8700c3dd0 ("netdevsim: Add dummy psample implementation")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-22 13:23:56 -07:00

266 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Mellanox Technologies. All rights reserved */
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/etherdevice.h>
#include <linux/inet.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <net/devlink.h>
#include <net/ip.h>
#include <net/psample.h>
#include <uapi/linux/ip.h>
#include <uapi/linux/udp.h>
#include "netdevsim.h"
#define NSIM_PSAMPLE_REPORT_INTERVAL_MS 100
#define NSIM_PSAMPLE_INVALID_TC 0xFFFF
#define NSIM_PSAMPLE_L4_DATA_LEN 100
struct nsim_dev_psample {
struct delayed_work psample_dw;
struct dentry *ddir;
struct psample_group *group;
u32 rate;
u32 group_num;
u32 trunc_size;
int in_ifindex;
int out_ifindex;
u16 out_tc;
u64 out_tc_occ_max;
u64 latency_max;
bool is_active;
};
static struct sk_buff *nsim_dev_psample_skb_build(void)
{
int tot_len, data_len = NSIM_PSAMPLE_L4_DATA_LEN;
struct sk_buff *skb;
struct udphdr *udph;
struct ethhdr *eth;
struct iphdr *iph;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return NULL;
tot_len = sizeof(struct iphdr) + sizeof(struct udphdr) + data_len;
skb_reset_mac_header(skb);
eth = skb_put(skb, sizeof(struct ethhdr));
eth_random_addr(eth->h_dest);
eth_random_addr(eth->h_source);
eth->h_proto = htons(ETH_P_IP);
skb->protocol = htons(ETH_P_IP);
skb_set_network_header(skb, skb->len);
iph = skb_put(skb, sizeof(struct iphdr));
iph->protocol = IPPROTO_UDP;
iph->saddr = in_aton("192.0.2.1");
iph->daddr = in_aton("198.51.100.1");
iph->version = 0x4;
iph->frag_off = 0;
iph->ihl = 0x5;
iph->tot_len = htons(tot_len);
iph->id = 0;
iph->ttl = 100;
iph->check = 0;
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
skb_set_transport_header(skb, skb->len);
udph = skb_put_zero(skb, sizeof(struct udphdr) + data_len);
get_random_bytes(&udph->source, sizeof(u16));
get_random_bytes(&udph->dest, sizeof(u16));
udph->len = htons(sizeof(struct udphdr) + data_len);
return skb;
}
static void nsim_dev_psample_md_prepare(const struct nsim_dev_psample *psample,
struct psample_metadata *md,
unsigned int len)
{
md->trunc_size = psample->trunc_size ? psample->trunc_size : len;
md->in_ifindex = psample->in_ifindex;
md->out_ifindex = psample->out_ifindex;
if (psample->out_tc != NSIM_PSAMPLE_INVALID_TC) {
md->out_tc = psample->out_tc;
md->out_tc_valid = 1;
}
if (psample->out_tc_occ_max) {
u64 out_tc_occ;
get_random_bytes(&out_tc_occ, sizeof(u64));
md->out_tc_occ = out_tc_occ & (psample->out_tc_occ_max - 1);
md->out_tc_occ_valid = 1;
}
if (psample->latency_max) {
u64 latency;
get_random_bytes(&latency, sizeof(u64));
md->latency = latency & (psample->latency_max - 1);
md->latency_valid = 1;
}
}
static void nsim_dev_psample_report_work(struct work_struct *work)
{
struct nsim_dev_psample *psample;
struct psample_metadata md = {};
struct sk_buff *skb;
unsigned long delay;
psample = container_of(work, struct nsim_dev_psample, psample_dw.work);
skb = nsim_dev_psample_skb_build();
if (!skb)
goto out;
nsim_dev_psample_md_prepare(psample, &md, skb->len);
psample_sample_packet(psample->group, skb, psample->rate, &md);
consume_skb(skb);
out:
delay = msecs_to_jiffies(NSIM_PSAMPLE_REPORT_INTERVAL_MS);
schedule_delayed_work(&psample->psample_dw, delay);
}
static int nsim_dev_psample_enable(struct nsim_dev *nsim_dev)
{
struct nsim_dev_psample *psample = nsim_dev->psample;
struct devlink *devlink;
unsigned long delay;
if (psample->is_active)
return -EBUSY;
devlink = priv_to_devlink(nsim_dev);
psample->group = psample_group_get(devlink_net(devlink),
psample->group_num);
if (!psample->group)
return -EINVAL;
delay = msecs_to_jiffies(NSIM_PSAMPLE_REPORT_INTERVAL_MS);
schedule_delayed_work(&psample->psample_dw, delay);
psample->is_active = true;
return 0;
}
static int nsim_dev_psample_disable(struct nsim_dev *nsim_dev)
{
struct nsim_dev_psample *psample = nsim_dev->psample;
if (!psample->is_active)
return -EINVAL;
psample->is_active = false;
cancel_delayed_work_sync(&psample->psample_dw);
psample_group_put(psample->group);
return 0;
}
static ssize_t nsim_dev_psample_enable_write(struct file *file,
const char __user *data,
size_t count, loff_t *ppos)
{
struct nsim_dev *nsim_dev = file->private_data;
bool enable;
int err;
err = kstrtobool_from_user(data, count, &enable);
if (err)
return err;
if (enable)
err = nsim_dev_psample_enable(nsim_dev);
else
err = nsim_dev_psample_disable(nsim_dev);
return err ? err : count;
}
static const struct file_operations nsim_psample_enable_fops = {
.open = simple_open,
.write = nsim_dev_psample_enable_write,
.llseek = generic_file_llseek,
.owner = THIS_MODULE,
};
int nsim_dev_psample_init(struct nsim_dev *nsim_dev)
{
struct nsim_dev_psample *psample;
int err;
psample = kzalloc(sizeof(*psample), GFP_KERNEL);
if (!psample)
return -ENOMEM;
nsim_dev->psample = psample;
INIT_DELAYED_WORK(&psample->psample_dw, nsim_dev_psample_report_work);
psample->ddir = debugfs_create_dir("psample", nsim_dev->ddir);
if (IS_ERR(psample->ddir)) {
err = PTR_ERR(psample->ddir);
goto err_psample_free;
}
/* Populate sampling parameters with sane defaults. */
psample->rate = 100;
debugfs_create_u32("rate", 0600, psample->ddir, &psample->rate);
psample->group_num = 10;
debugfs_create_u32("group_num", 0600, psample->ddir,
&psample->group_num);
psample->trunc_size = 0;
debugfs_create_u32("trunc_size", 0600, psample->ddir,
&psample->trunc_size);
psample->in_ifindex = 1;
debugfs_create_u32("in_ifindex", 0600, psample->ddir,
&psample->in_ifindex);
psample->out_ifindex = 2;
debugfs_create_u32("out_ifindex", 0600, psample->ddir,
&psample->out_ifindex);
psample->out_tc = 0;
debugfs_create_u16("out_tc", 0600, psample->ddir, &psample->out_tc);
psample->out_tc_occ_max = 10000;
debugfs_create_u64("out_tc_occ_max", 0600, psample->ddir,
&psample->out_tc_occ_max);
psample->latency_max = 50;
debugfs_create_u64("latency_max", 0600, psample->ddir,
&psample->latency_max);
debugfs_create_file("enable", 0200, psample->ddir, nsim_dev,
&nsim_psample_enable_fops);
return 0;
err_psample_free:
kfree(nsim_dev->psample);
return err;
}
void nsim_dev_psample_exit(struct nsim_dev *nsim_dev)
{
debugfs_remove_recursive(nsim_dev->psample->ddir);
if (nsim_dev->psample->is_active) {
cancel_delayed_work_sync(&nsim_dev->psample->psample_dw);
psample_group_put(nsim_dev->psample->group);
}
kfree(nsim_dev->psample);
}