diff options
Diffstat (limited to 'net/dccp/probe.c')
| -rw-r--r-- | net/dccp/probe.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/net/dccp/probe.c b/net/dccp/probe.c new file mode 100644 index 00000000..0a8d6ebd --- /dev/null +++ b/net/dccp/probe.c @@ -0,0 +1,208 @@ +/* + * 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 kiocb *iocb, 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 setup_jprobe(void) +{ + int ret = register_jprobe(&dccp_send_probe); + + if (ret) { + request_module("dccp"); + ret = register_jprobe(&dccp_send_probe); + } + return ret; +} + +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_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops)) + goto err0; + + ret = setup_jprobe(); + if (ret) + goto err1; + + pr_info("DCCP watch registered (port=%d)\n", port); + return 0; +err1: + proc_net_remove(&init_net, procname); +err0: + kfifo_free(&dccpw.fifo); + return ret; +} +module_init(dccpprobe_init); + +static __exit void dccpprobe_exit(void) +{ + kfifo_free(&dccpw.fifo); + proc_net_remove(&init_net, procname); + 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"); |