[TCP] tcp_probe: improvements for net-2.6.22

Change tcp_probe to use ktime (needed to add one export).
Add option to only get events when cwnd changes - from Doug Leith

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/kernel/time.c b/kernel/time.c
index a1439f4..ba18ec4 100644 (file)
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -452,6 +452,7 @@ struct timespec ns_to_timespec(const s64 nsec)
 
        return ts;
 }
+EXPORT_SYMBOL(ns_to_timespec);
 
 /**
  * ns_to_timeval - Convert nanoseconds to timeval

diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c
index 61f406f..3938d5d 100644 (file)
--- a/net/ipv4/tcp_probe.c
+++ b/net/ipv4/tcp_probe.c
@@ -26,6 +26,8 @@
 #include <linux/proc_fs.h>
 #include <linux/module.h>
 #include <linux/kfifo.h>
+#include <linux/ktime.h>
+#include <linux/time.h>
 #include <linux/vmalloc.h>
 
 #include <net/tcp.h>
@@ -34,43 +36,45 @@ MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
 MODULE_DESCRIPTION("TCP cwnd snooper");
 MODULE_LICENSE("GPL");
 
-static int port = 0;
+static int port __read_mostly = 0;
 MODULE_PARM_DESC(port, "Port to match (0=all)");
 module_param(port, int, 0);
 
-static int bufsize = 64*1024;
+static int bufsize __read_mostly = 64*1024;
 MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
 module_param(bufsize, int, 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 {
-       struct kfifo  *fifo;
-       spinlock_t    lock;
+       struct kfifo    *fifo;
+       spinlock_t      lock;
        wait_queue_head_t wait;
-       struct timeval tstart;
+       ktime_t         start;
+       u32             lastcwnd;
 } tcpw;
 
+/*
+ * Print to log with timestamps.
+ * FIXME: causes an extra copy
+ */
 static void printl(const char *fmt, ...)
 {
        va_list args;
        int len;
-       struct timeval now;
+       struct timespec tv;
        char tbuf[256];
 
        va_start(args, fmt);
-       do_gettimeofday(&now);
+       /* want monotonic time since start of tcp_probe */
+       tv = ktime_to_timespec(ktime_sub(ktime_get(), tcpw.start));
 
-       now.tv_sec -= tcpw.tstart.tv_sec;
-       now.tv_usec -= tcpw.tstart.tv_usec;
-       if (now.tv_usec < 0) {
-               --now.tv_sec;
-               now.tv_usec += 1000000;
-       }
-
-       len = sprintf(tbuf, "%lu.%06lu ",
-                     (unsigned long) now.tv_sec,
-                     (unsigned long) now.tv_usec);
+       len = sprintf(tbuf, "%lu.%09lu ",
+                     (unsigned long) tv.tv_sec, (unsigned long) tv.tv_nsec);
        len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
        va_end(args);
 
@@ -78,38 +82,44 @@ static void printl(const char *fmt, ...)
        wake_up(&tcpw.wait);
 }
 
-static int jtcp_sendmsg(struct kiocb *iocb, struct sock *sk,
-                       struct msghdr *msg, size_t size)
+/*
+ * 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 len)
 {
        const struct tcp_sock *tp = tcp_sk(sk);
        const struct inet_sock *inet = inet_sk(sk);
 
-       if (port == 0 || ntohs(inet->dport) == port ||
-           ntohs(inet->sport) == port) {
+       /* Only update if port matches */
+       if ((port == 0 || ntohs(inet->dport) == port || ntohs(inet->sport) == port)
+           && (full || tp->snd_cwnd != tcpw.lastcwnd)) {
                printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %#x %#x %u %u %u\n",
                       NIPQUAD(inet->saddr), ntohs(inet->sport),
                       NIPQUAD(inet->daddr), ntohs(inet->dport),
-                      size, tp->snd_nxt, tp->snd_una,
+                      skb->len, tp->snd_nxt, tp->snd_una,
                       tp->snd_cwnd, tcp_current_ssthresh(sk),
-                      tp->snd_wnd);
+                      tp->snd_wnd, tp->srtt >> 3);
+               tcpw.lastcwnd = tp->snd_cwnd;
        }
 
        jprobe_return();
        return 0;
 }
 
-static struct jprobe tcp_send_probe = {
+static struct jprobe tcp_probe = {
        .kp = {
-               .symbol_name    = "tcp_sendmsg",
+               .symbol_name    = "tcp_rcv_established",
        },
-       .entry  = JPROBE_ENTRY(jtcp_sendmsg),
+       .entry  = JPROBE_ENTRY(jtcp_rcv_established),
 };
 
 
 static int tcpprobe_open(struct inode * inode, struct file * file)
 {
        kfifo_reset(tcpw.fifo);
-       do_gettimeofday(&tcpw.tstart);
+       tcpw.start = ktime_get();
        return 0;
 }
 
@@ -162,7 +172,7 @@ static __init int tcpprobe_init(void)
        if (!proc_net_fops_create(procname, S_IRUSR, &tcpprobe_fops))
                goto err0;
 
-       ret = register_jprobe(&tcp_send_probe);
+       ret = register_jprobe(&tcp_probe);
        if (ret)
                goto err1;
 
@@ -180,7 +190,7 @@ static __exit void tcpprobe_exit(void)
 {
        kfifo_free(tcpw.fifo);
        proc_net_remove(procname);
-       unregister_jprobe(&tcp_send_probe);
+       unregister_jprobe(&tcp_probe);
 
 }
 module_exit(tcpprobe_exit);