mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-09 20:46:44 +07:00
95c9617472
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
261 lines
6.2 KiB
C
261 lines
6.2 KiB
C
/*
|
|
* tcpprobe - Observe the TCP flow with kprobes.
|
|
*
|
|
* The idea for this came from Werner Almesberger's umlsim
|
|
* Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/socket.h>
|
|
#include <linux/tcp.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/ktime.h>
|
|
#include <linux/time.h>
|
|
#include <net/net_namespace.h>
|
|
|
|
#include <net/tcp.h>
|
|
|
|
MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
|
|
MODULE_DESCRIPTION("TCP cwnd snooper");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION("1.1");
|
|
|
|
static int port __read_mostly = 0;
|
|
MODULE_PARM_DESC(port, "Port to match (0=all)");
|
|
module_param(port, int, 0);
|
|
|
|
static unsigned int bufsize __read_mostly = 4096;
|
|
MODULE_PARM_DESC(bufsize, "Log buffer size in packets (4096)");
|
|
module_param(bufsize, uint, 0);
|
|
|
|
static int full __read_mostly;
|
|
MODULE_PARM_DESC(full, "Full log (1=every ack packet received, 0=only cwnd changes)");
|
|
module_param(full, int, 0);
|
|
|
|
static const char procname[] = "tcpprobe";
|
|
|
|
struct tcp_log {
|
|
ktime_t tstamp;
|
|
__be32 saddr, daddr;
|
|
__be16 sport, dport;
|
|
u16 length;
|
|
u32 snd_nxt;
|
|
u32 snd_una;
|
|
u32 snd_wnd;
|
|
u32 snd_cwnd;
|
|
u32 ssthresh;
|
|
u32 srtt;
|
|
};
|
|
|
|
static struct {
|
|
spinlock_t lock;
|
|
wait_queue_head_t wait;
|
|
ktime_t start;
|
|
u32 lastcwnd;
|
|
|
|
unsigned long head, tail;
|
|
struct tcp_log *log;
|
|
} tcp_probe;
|
|
|
|
|
|
static inline int tcp_probe_used(void)
|
|
{
|
|
return (tcp_probe.head - tcp_probe.tail) & (bufsize - 1);
|
|
}
|
|
|
|
static inline int tcp_probe_avail(void)
|
|
{
|
|
return bufsize - tcp_probe_used() - 1;
|
|
}
|
|
|
|
/*
|
|
* Hook inserted to be called before each receive packet.
|
|
* Note: arguments must match tcp_rcv_established()!
|
|
*/
|
|
static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
|
|
struct tcphdr *th, unsigned int len)
|
|
{
|
|
const struct tcp_sock *tp = tcp_sk(sk);
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
|
|
/* Only update if port matches */
|
|
if ((port == 0 || ntohs(inet->inet_dport) == port ||
|
|
ntohs(inet->inet_sport) == port) &&
|
|
(full || tp->snd_cwnd != tcp_probe.lastcwnd)) {
|
|
|
|
spin_lock(&tcp_probe.lock);
|
|
/* If log fills, just silently drop */
|
|
if (tcp_probe_avail() > 1) {
|
|
struct tcp_log *p = tcp_probe.log + tcp_probe.head;
|
|
|
|
p->tstamp = ktime_get();
|
|
p->saddr = inet->inet_saddr;
|
|
p->sport = inet->inet_sport;
|
|
p->daddr = inet->inet_daddr;
|
|
p->dport = inet->inet_dport;
|
|
p->length = skb->len;
|
|
p->snd_nxt = tp->snd_nxt;
|
|
p->snd_una = tp->snd_una;
|
|
p->snd_cwnd = tp->snd_cwnd;
|
|
p->snd_wnd = tp->snd_wnd;
|
|
p->ssthresh = tcp_current_ssthresh(sk);
|
|
p->srtt = tp->srtt >> 3;
|
|
|
|
tcp_probe.head = (tcp_probe.head + 1) & (bufsize - 1);
|
|
}
|
|
tcp_probe.lastcwnd = tp->snd_cwnd;
|
|
spin_unlock(&tcp_probe.lock);
|
|
|
|
wake_up(&tcp_probe.wait);
|
|
}
|
|
|
|
jprobe_return();
|
|
return 0;
|
|
}
|
|
|
|
static struct jprobe tcp_jprobe = {
|
|
.kp = {
|
|
.symbol_name = "tcp_rcv_established",
|
|
},
|
|
.entry = jtcp_rcv_established,
|
|
};
|
|
|
|
static int tcpprobe_open(struct inode *inode, struct file *file)
|
|
{
|
|
/* Reset (empty) log */
|
|
spin_lock_bh(&tcp_probe.lock);
|
|
tcp_probe.head = tcp_probe.tail = 0;
|
|
tcp_probe.start = ktime_get();
|
|
spin_unlock_bh(&tcp_probe.lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tcpprobe_sprint(char *tbuf, int n)
|
|
{
|
|
const struct tcp_log *p
|
|
= tcp_probe.log + tcp_probe.tail;
|
|
struct timespec tv
|
|
= ktime_to_timespec(ktime_sub(p->tstamp, tcp_probe.start));
|
|
|
|
return scnprintf(tbuf, n,
|
|
"%lu.%09lu %pI4:%u %pI4:%u %d %#x %#x %u %u %u %u\n",
|
|
(unsigned long) tv.tv_sec,
|
|
(unsigned long) tv.tv_nsec,
|
|
&p->saddr, ntohs(p->sport),
|
|
&p->daddr, ntohs(p->dport),
|
|
p->length, p->snd_nxt, p->snd_una,
|
|
p->snd_cwnd, p->ssthresh, p->snd_wnd, p->srtt);
|
|
}
|
|
|
|
static ssize_t tcpprobe_read(struct file *file, char __user *buf,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
int error = 0;
|
|
size_t cnt = 0;
|
|
|
|
if (!buf)
|
|
return -EINVAL;
|
|
|
|
while (cnt < len) {
|
|
char tbuf[164];
|
|
int width;
|
|
|
|
/* Wait for data in buffer */
|
|
error = wait_event_interruptible(tcp_probe.wait,
|
|
tcp_probe_used() > 0);
|
|
if (error)
|
|
break;
|
|
|
|
spin_lock_bh(&tcp_probe.lock);
|
|
if (tcp_probe.head == tcp_probe.tail) {
|
|
/* multiple readers race? */
|
|
spin_unlock_bh(&tcp_probe.lock);
|
|
continue;
|
|
}
|
|
|
|
width = tcpprobe_sprint(tbuf, sizeof(tbuf));
|
|
|
|
if (cnt + width < len)
|
|
tcp_probe.tail = (tcp_probe.tail + 1) & (bufsize - 1);
|
|
|
|
spin_unlock_bh(&tcp_probe.lock);
|
|
|
|
/* if record greater than space available
|
|
return partial buffer (so far) */
|
|
if (cnt + width >= len)
|
|
break;
|
|
|
|
if (copy_to_user(buf + cnt, tbuf, width))
|
|
return -EFAULT;
|
|
cnt += width;
|
|
}
|
|
|
|
return cnt == 0 ? error : cnt;
|
|
}
|
|
|
|
static const struct file_operations tcpprobe_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = tcpprobe_open,
|
|
.read = tcpprobe_read,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static __init int tcpprobe_init(void)
|
|
{
|
|
int ret = -ENOMEM;
|
|
|
|
init_waitqueue_head(&tcp_probe.wait);
|
|
spin_lock_init(&tcp_probe.lock);
|
|
|
|
if (bufsize == 0)
|
|
return -EINVAL;
|
|
|
|
bufsize = roundup_pow_of_two(bufsize);
|
|
tcp_probe.log = kcalloc(bufsize, sizeof(struct tcp_log), GFP_KERNEL);
|
|
if (!tcp_probe.log)
|
|
goto err0;
|
|
|
|
if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &tcpprobe_fops))
|
|
goto err0;
|
|
|
|
ret = register_jprobe(&tcp_jprobe);
|
|
if (ret)
|
|
goto err1;
|
|
|
|
pr_info("probe registered (port=%d) bufsize=%u\n", port, bufsize);
|
|
return 0;
|
|
err1:
|
|
proc_net_remove(&init_net, procname);
|
|
err0:
|
|
kfree(tcp_probe.log);
|
|
return ret;
|
|
}
|
|
module_init(tcpprobe_init);
|
|
|
|
static __exit void tcpprobe_exit(void)
|
|
{
|
|
proc_net_remove(&init_net, procname);
|
|
unregister_jprobe(&tcp_jprobe);
|
|
kfree(tcp_probe.log);
|
|
}
|
|
module_exit(tcpprobe_exit);
|