diff options
Diffstat (limited to 'net/dccp/probe.c')
| -rw-r--r-- | net/dccp/probe.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/net/dccp/probe.c b/net/dccp/probe.c new file mode 100644 index 000000000000..146496fce2e2 --- /dev/null +++ b/net/dccp/probe.c @@ -0,0 +1,198 @@ +/* + * 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 "dccp.h" +#include "ccid.h" +#include "ccids/ccid3.h" + +static int port; + +static int bufsize = 64 * 1024; + +static const char procname[] = "dccpprobe"; + +struct { + struct kfifo *fifo; + spinlock_t lock; + wait_queue_head_t wait; + struct timeval tstart; +} dccpw; + +static void printl(const char *fmt, ...) +{ + va_list args; + int len; + struct timeval now; + char tbuf[256]; + + va_start(args, fmt); + do_gettimeofday(&now); + + now.tv_sec -= dccpw.tstart.tv_sec; + now.tv_usec -= dccpw.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 += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args); + va_end(args); + + kfifo_put(dccpw.fifo, tbuf, len); + wake_up(&dccpw.wait); +} + +static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk, + struct msghdr *msg, size_t size) +{ + const struct dccp_minisock *dmsk = dccp_msk(sk); + const struct inet_sock *inet = inet_sk(sk); + const struct ccid3_hc_tx_sock *hctx; + + if (dmsk->dccpms_tx_ccid == DCCPC_CCID3) + hctx = ccid3_hc_tx_sk(sk); + else + hctx = NULL; + + if (port == 0 || ntohs(inet->dport) == port || + ntohs(inet->sport) == port) { + if (hctx) + printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %d\n", + NIPQUAD(inet->saddr), ntohs(inet->sport), + NIPQUAD(inet->daddr), ntohs(inet->dport), size, + hctx->ccid3hctx_s, hctx->ccid3hctx_rtt, + hctx->ccid3hctx_p, hctx->ccid3hctx_t_ipi); + else + printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d\n", + NIPQUAD(inet->saddr), ntohs(inet->sport), + NIPQUAD(inet->daddr), ntohs(inet->dport), size); + } + + jprobe_return(); + return 0; +} + +static struct jprobe dccp_send_probe = { + .kp = { .addr = (kprobe_opcode_t *)&dccp_sendmsg, }, + .entry = (kprobe_opcode_t *)&jdccp_sendmsg, +}; + +static int dccpprobe_open(struct inode *inode, struct file *file) +{ + kfifo_reset(dccpw.fifo); + do_gettimeofday(&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 || len < 0) + 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_get(dccpw.fifo, tbuf, len); + error = copy_to_user(buf, tbuf, cnt); + +out_free: + vfree(tbuf); + + return error ? error : cnt; +} + +static struct file_operations dccpprobe_fops = { + .owner = THIS_MODULE, + .open = dccpprobe_open, + .read = dccpprobe_read, +}; + +static __init int dccpprobe_init(void) +{ + int ret = -ENOMEM; + + init_waitqueue_head(&dccpw.wait); + spin_lock_init(&dccpw.lock); + dccpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &dccpw.lock); + + if (!proc_net_fops_create(procname, S_IRUSR, &dccpprobe_fops)) + goto err0; + + ret = register_jprobe(&dccp_send_probe); + if (ret) + goto err1; + + pr_info("DCCP watch registered (port=%d)\n", port); + return 0; +err1: + proc_net_remove(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(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"); |