forked from Minki/linux
70df2311ee
The suseconds_t et al. are not necessarily any particular type on every platform, so cast to unsigned long so that we can use one printf format string and avoid warnings across the board Signed-off-by: David S. Miller <davem@davemloft.net>
182 lines
4.2 KiB
C
182 lines
4.2 KiB
C
/*
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* tcpprobe - Observe the TCP flow with kprobes.
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*
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* The idea for this came from Werner Almesberger's umlsim
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* Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/kernel.h>
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#include <linux/kprobes.h>
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#include <linux/socket.h>
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#include <linux/tcp.h>
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#include <linux/proc_fs.h>
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#include <linux/module.h>
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#include <linux/kfifo.h>
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#include <linux/vmalloc.h>
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#include <net/tcp.h>
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MODULE_AUTHOR("Stephen Hemminger <shemminger@osdl.org>");
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MODULE_DESCRIPTION("TCP cwnd snooper");
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MODULE_LICENSE("GPL");
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static int port = 0;
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MODULE_PARM_DESC(port, "Port to match (0=all)");
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module_param(port, int, 0);
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static int bufsize = 64*1024;
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MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
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module_param(bufsize, int, 0);
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static const char procname[] = "tcpprobe";
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struct {
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struct kfifo *fifo;
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spinlock_t lock;
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wait_queue_head_t wait;
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struct timeval tstart;
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} tcpw;
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static void printl(const char *fmt, ...)
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{
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va_list args;
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int len;
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struct timeval now;
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char tbuf[256];
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va_start(args, fmt);
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do_gettimeofday(&now);
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now.tv_sec -= tcpw.tstart.tv_sec;
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now.tv_usec -= tcpw.tstart.tv_usec;
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if (now.tv_usec < 0) {
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--now.tv_sec;
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now.tv_usec += 1000000;
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}
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len = sprintf(tbuf, "%lu.%06lu ",
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(unsigned long) now.tv_sec,
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(unsigned long) now.tv_usec);
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len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
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va_end(args);
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kfifo_put(tcpw.fifo, tbuf, len);
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wake_up(&tcpw.wait);
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}
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static int jtcp_sendmsg(struct kiocb *iocb, struct sock *sk,
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struct msghdr *msg, size_t size)
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{
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const struct tcp_sock *tp = tcp_sk(sk);
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const struct inet_sock *inet = inet_sk(sk);
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if (port == 0 || ntohs(inet->dport) == port ||
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ntohs(inet->sport) == port) {
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printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %#x %#x %u %u %u\n",
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NIPQUAD(inet->saddr), ntohs(inet->sport),
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NIPQUAD(inet->daddr), ntohs(inet->dport),
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size, tp->snd_nxt, tp->snd_una,
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tp->snd_cwnd, tcp_current_ssthresh(sk),
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tp->snd_wnd);
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}
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jprobe_return();
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return 0;
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}
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static struct jprobe tcp_send_probe = {
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.kp = { .addr = (kprobe_opcode_t *) &tcp_sendmsg, },
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.entry = (kprobe_opcode_t *) &jtcp_sendmsg,
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};
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static int tcpprobe_open(struct inode * inode, struct file * file)
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{
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kfifo_reset(tcpw.fifo);
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do_gettimeofday(&tcpw.tstart);
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return 0;
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}
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static ssize_t tcpprobe_read(struct file *file, char __user *buf,
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size_t len, loff_t *ppos)
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{
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int error = 0, cnt;
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unsigned char *tbuf;
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if (!buf || len < 0)
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return -EINVAL;
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if (len == 0)
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return 0;
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tbuf = vmalloc(len);
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if (!tbuf)
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return -ENOMEM;
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error = wait_event_interruptible(tcpw.wait,
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__kfifo_len(tcpw.fifo) != 0);
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if (error)
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return error;
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cnt = kfifo_get(tcpw.fifo, tbuf, len);
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error = copy_to_user(buf, tbuf, cnt);
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vfree(tbuf);
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return error ? error : cnt;
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}
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static struct file_operations tcpprobe_fops = {
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.owner = THIS_MODULE,
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.open = tcpprobe_open,
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.read = tcpprobe_read,
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};
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static __init int tcpprobe_init(void)
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{
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int ret = -ENOMEM;
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init_waitqueue_head(&tcpw.wait);
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spin_lock_init(&tcpw.lock);
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tcpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &tcpw.lock);
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if (!proc_net_fops_create(procname, S_IRUSR, &tcpprobe_fops))
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goto err0;
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ret = register_jprobe(&tcp_send_probe);
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if (ret)
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goto err1;
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pr_info("TCP watch registered (port=%d)\n", port);
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return 0;
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err1:
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proc_net_remove(procname);
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err0:
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kfifo_free(tcpw.fifo);
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return ret;
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}
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module_init(tcpprobe_init);
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static __exit void tcpprobe_exit(void)
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{
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kfifo_free(tcpw.fifo);
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proc_net_remove(procname);
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unregister_jprobe(&tcp_send_probe);
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}
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module_exit(tcpprobe_exit);
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