summaryrefslogtreecommitdiff
path: root/net/dccp/probe.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/dccp/probe.c')
-rw-r--r--net/dccp/probe.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/net/dccp/probe.c b/net/dccp/probe.c
new file mode 100644
index 000000000..d8346d0ea
--- /dev/null
+++ b/net/dccp/probe.c
@@ -0,0 +1,202 @@
+/*
+ * dccp_probe - Observe the DCCP flow with kprobes.
+ *
+ * The idea for this came from Werner Almesberger's umlsim
+ * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
+ *
+ * Modified for DCCP from Stephen Hemminger's code
+ * Copyright (C) 2006, Ian McDonald <ian.mcdonald@jandi.co.nz>
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/socket.h>
+#include <linux/dccp.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/kfifo.h>
+#include <linux/vmalloc.h>
+#include <linux/gfp.h>
+#include <net/net_namespace.h>
+
+#include "dccp.h"
+#include "ccid.h"
+#include "ccids/ccid3.h"
+
+static int port;
+
+static int bufsize = 64 * 1024;
+
+static const char procname[] = "dccpprobe";
+
+static struct {
+ struct kfifo fifo;
+ spinlock_t lock;
+ wait_queue_head_t wait;
+ struct timespec tstart;
+} dccpw;
+
+static void printl(const char *fmt, ...)
+{
+ va_list args;
+ int len;
+ struct timespec now;
+ char tbuf[256];
+
+ va_start(args, fmt);
+ getnstimeofday(&now);
+
+ now = timespec_sub(now, dccpw.tstart);
+
+ len = sprintf(tbuf, "%lu.%06lu ",
+ (unsigned long) now.tv_sec,
+ (unsigned long) now.tv_nsec / NSEC_PER_USEC);
+ len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
+ va_end(args);
+
+ kfifo_in_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
+ wake_up(&dccpw.wait);
+}
+
+static int jdccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+ const struct inet_sock *inet = inet_sk(sk);
+ struct ccid3_hc_tx_sock *hc = NULL;
+
+ if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
+ hc = ccid3_hc_tx_sk(sk);
+
+ if (port == 0 || ntohs(inet->inet_dport) == port ||
+ ntohs(inet->inet_sport) == port) {
+ if (hc)
+ printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n",
+ &inet->inet_saddr, ntohs(inet->inet_sport),
+ &inet->inet_daddr, ntohs(inet->inet_dport), size,
+ hc->tx_s, hc->tx_rtt, hc->tx_p,
+ hc->tx_x_calc, hc->tx_x_recv >> 6,
+ hc->tx_x >> 6, hc->tx_t_ipi);
+ else
+ printl("%pI4:%u %pI4:%u %d\n",
+ &inet->inet_saddr, ntohs(inet->inet_sport),
+ &inet->inet_daddr, ntohs(inet->inet_dport),
+ size);
+ }
+
+ jprobe_return();
+ return 0;
+}
+
+static struct jprobe dccp_send_probe = {
+ .kp = {
+ .symbol_name = "dccp_sendmsg",
+ },
+ .entry = jdccp_sendmsg,
+};
+
+static int dccpprobe_open(struct inode *inode, struct file *file)
+{
+ kfifo_reset(&dccpw.fifo);
+ getnstimeofday(&dccpw.tstart);
+ return 0;
+}
+
+static ssize_t dccpprobe_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ int error = 0, cnt = 0;
+ unsigned char *tbuf;
+
+ if (!buf)
+ return -EINVAL;
+
+ if (len == 0)
+ return 0;
+
+ tbuf = vmalloc(len);
+ if (!tbuf)
+ return -ENOMEM;
+
+ error = wait_event_interruptible(dccpw.wait,
+ kfifo_len(&dccpw.fifo) != 0);
+ if (error)
+ goto out_free;
+
+ cnt = kfifo_out_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
+ error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
+
+out_free:
+ vfree(tbuf);
+
+ return error ? error : cnt;
+}
+
+static const struct file_operations dccpprobe_fops = {
+ .owner = THIS_MODULE,
+ .open = dccpprobe_open,
+ .read = dccpprobe_read,
+ .llseek = noop_llseek,
+};
+
+static __init int dccpprobe_init(void)
+{
+ int ret = -ENOMEM;
+
+ init_waitqueue_head(&dccpw.wait);
+ spin_lock_init(&dccpw.lock);
+ if (kfifo_alloc(&dccpw.fifo, bufsize, GFP_KERNEL))
+ return ret;
+ if (!proc_create(procname, S_IRUSR, init_net.proc_net, &dccpprobe_fops))
+ goto err0;
+
+ ret = register_jprobe(&dccp_send_probe);
+ if (ret) {
+ ret = request_module("dccp");
+ if (!ret)
+ ret = register_jprobe(&dccp_send_probe);
+ }
+
+ if (ret)
+ goto err1;
+
+ pr_info("DCCP watch registered (port=%d)\n", port);
+ return 0;
+err1:
+ remove_proc_entry(procname, init_net.proc_net);
+err0:
+ kfifo_free(&dccpw.fifo);
+ return ret;
+}
+module_init(dccpprobe_init);
+
+static __exit void dccpprobe_exit(void)
+{
+ kfifo_free(&dccpw.fifo);
+ remove_proc_entry(procname, init_net.proc_net);
+ unregister_jprobe(&dccp_send_probe);
+
+}
+module_exit(dccpprobe_exit);
+
+MODULE_PARM_DESC(port, "Port to match (0=all)");
+module_param(port, int, 0);
+
+MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
+module_param(bufsize, int, 0);
+
+MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>");
+MODULE_DESCRIPTION("DCCP snooper");
+MODULE_LICENSE("GPL");