diff options
Diffstat (limited to 'net/ipv4/tcp_probe.c')
-rw-r--r-- | net/ipv4/tcp_probe.c | 301 |
1 files changed, 0 insertions, 301 deletions
diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c deleted file mode 100644 index 697f4c67b2e3..000000000000 --- a/net/ipv4/tcp_probe.c +++ /dev/null @@ -1,301 +0,0 @@ -/* - * 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); |