+++ /dev/null
-/*
- * 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;
-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 unsigned int fwmark __read_mostly;
-MODULE_PARM_DESC(fwmark, "skb mark to match (0=no mark)");
-module_param(fwmark, 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;
- union {
- struct sockaddr raw;
- struct sockaddr_in v4;
- struct sockaddr_in6 v6;
- } src, dst;
- u16 length;
- u32 snd_nxt;
- u32 snd_una;
- u32 snd_wnd;
- u32 rcv_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;
-}
-
-#define tcp_probe_copy_fl_to_si4(inet, si4, mem) \
- do { \
- si4.sin_family = AF_INET; \
- si4.sin_port = inet->inet_##mem##port; \
- si4.sin_addr.s_addr = inet->inet_##mem##addr; \
- } while (0) \
-
-/*
- * Hook inserted to be called before each receive packet.
- * Note: arguments must match tcp_rcv_established()!
- */
-static void jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
- const struct tcphdr *th)
-{
- unsigned int len = skb->len;
- const struct tcp_sock *tp = tcp_sk(sk);
- const struct inet_sock *inet = inet_sk(sk);
-
- /* Only update if port or skb mark matches */
- if (((port == 0 && fwmark == 0) ||
- ntohs(inet->inet_dport) == port ||
- ntohs(inet->inet_sport) == port ||
- (fwmark > 0 && skb->mark == fwmark)) &&
- (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();
- switch (sk->sk_family) {
- case AF_INET:
- tcp_probe_copy_fl_to_si4(inet, p->src.v4, s);
- tcp_probe_copy_fl_to_si4(inet, p->dst.v4, d);
- break;
- case AF_INET6:
- memset(&p->src.v6, 0, sizeof(p->src.v6));
- memset(&p->dst.v6, 0, sizeof(p->dst.v6));
-#if IS_ENABLED(CONFIG_IPV6)
- p->src.v6.sin6_family = AF_INET6;
- p->src.v6.sin6_port = inet->inet_sport;
- p->src.v6.sin6_addr = inet6_sk(sk)->saddr;
-
- p->dst.v6.sin6_family = AF_INET6;
- p->dst.v6.sin6_port = inet->inet_dport;
- p->dst.v6.sin6_addr = sk->sk_v6_daddr;
-#endif
- break;
- default:
- BUG();
- }
-
- p->length = 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->rcv_wnd = tp->rcv_wnd;
- p->ssthresh = tcp_current_ssthresh(sk);
- p->srtt = tp->srtt_us >> 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();
-}
-
-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 timespec64 ts
- = ktime_to_timespec64(ktime_sub(p->tstamp, tcp_probe.start));
-
- return scnprintf(tbuf, n,
- "%lu.%09lu %pISpc %pISpc %d %#x %#x %u %u %u %u %u\n",
- (unsigned long)ts.tv_sec,
- (unsigned long)ts.tv_nsec,
- &p->src, &p->dst, p->length, p->snd_nxt, p->snd_una,
- p->snd_cwnd, p->ssthresh, p->snd_wnd, p->srtt, p->rcv_wnd);
-}
-
-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[256];
- 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;
-
- /* Warning: if the function signature of tcp_rcv_established,
- * has been changed, you also have to change the signature of
- * jtcp_rcv_established, otherwise you end up right here!
- */
- BUILD_BUG_ON(__same_type(tcp_rcv_established,
- jtcp_rcv_established) == 0);
-
- 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_create(procname, S_IRUSR, init_net.proc_net, &tcpprobe_fops))
- goto err0;
-
- ret = register_jprobe(&tcp_jprobe);
- if (ret)
- goto err1;
-
- pr_info("probe registered (port=%d/fwmark=%u) bufsize=%u\n",
- port, fwmark, bufsize);
- return 0;
- err1:
- remove_proc_entry(procname, init_net.proc_net);
- err0:
- kfree(tcp_probe.log);
- return ret;
-}
-module_init(tcpprobe_init);
-
-static __exit void tcpprobe_exit(void)
-{
- remove_proc_entry(procname, init_net.proc_net);
- unregister_jprobe(&tcp_jprobe);
- kfree(tcp_probe.log);
-}
-module_exit(tcpprobe_exit);
projects / openwrt / staging / blogic.git / commitdiff