diff options
Diffstat (limited to 'net/sctp/probe.c')
| -rw-r--r-- | net/sctp/probe.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/net/sctp/probe.c b/net/sctp/probe.c new file mode 100644 index 00000000..bc6cd75c --- /dev/null +++ b/net/sctp/probe.c @@ -0,0 +1,217 @@ +/* + * sctp_probe - Observe the SCTP flow with kprobes. + * + * The idea for this came from Werner Almesberger's umlsim + * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org> + * + * Modified for SCTP from Stephen Hemminger's code + * Copyright (C) 2010, Wei Yongjun <yjwei@cn.fujitsu.com> + * + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/kprobes.h> +#include <linux/socket.h> +#include <linux/sctp.h> +#include <linux/proc_fs.h> +#include <linux/vmalloc.h> +#include <linux/module.h> +#include <linux/kfifo.h> +#include <linux/time.h> +#include <net/net_namespace.h> + +#include <net/sctp/sctp.h> +#include <net/sctp/sm.h> + +MODULE_AUTHOR("Wei Yongjun <yjwei@cn.fujitsu.com>"); +MODULE_DESCRIPTION("SCTP snooper"); +MODULE_LICENSE("GPL"); + +static int port __read_mostly = 0; +MODULE_PARM_DESC(port, "Port to match (0=all)"); +module_param(port, int, 0); + +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 = 1; +MODULE_PARM_DESC(full, "Full log (1=every ack packet received, 0=only cwnd changes)"); +module_param(full, int, 0); + +static const char procname[] = "sctpprobe"; + +static struct { + struct kfifo fifo; + spinlock_t lock; + wait_queue_head_t wait; + struct timespec tstart; +} sctpw; + +static void printl(const char *fmt, ...) +{ + va_list args; + int len; + char tbuf[256]; + + va_start(args, fmt); + len = vscnprintf(tbuf, sizeof(tbuf), fmt, args); + va_end(args); + + kfifo_in_locked(&sctpw.fifo, tbuf, len, &sctpw.lock); + wake_up(&sctpw.wait); +} + +static int sctpprobe_open(struct inode *inode, struct file *file) +{ + kfifo_reset(&sctpw.fifo); + getnstimeofday(&sctpw.tstart); + + return 0; +} + +static ssize_t sctpprobe_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(sctpw.wait, + kfifo_len(&sctpw.fifo) != 0); + if (error) + goto out_free; + + cnt = kfifo_out_locked(&sctpw.fifo, tbuf, len, &sctpw.lock); + error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0; + +out_free: + vfree(tbuf); + + return error ? error : cnt; +} + +static const struct file_operations sctpprobe_fops = { + .owner = THIS_MODULE, + .open = sctpprobe_open, + .read = sctpprobe_read, + .llseek = noop_llseek, +}; + +sctp_disposition_t jsctp_sf_eat_sack(const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + const sctp_subtype_t type, + void *arg, + sctp_cmd_seq_t *commands) +{ + struct sctp_transport *sp; + static __u32 lcwnd = 0; + struct timespec now; + + sp = asoc->peer.primary_path; + + if ((full || sp->cwnd != lcwnd) && + (!port || asoc->peer.port == port || + ep->base.bind_addr.port == port)) { + lcwnd = sp->cwnd; + + getnstimeofday(&now); + now = timespec_sub(now, sctpw.tstart); + + printl("%lu.%06lu ", (unsigned long) now.tv_sec, + (unsigned long) now.tv_nsec / NSEC_PER_USEC); + + printl("%p %5d %5d %5d %8d %5d ", asoc, + ep->base.bind_addr.port, asoc->peer.port, + asoc->pathmtu, asoc->peer.rwnd, asoc->unack_data); + + list_for_each_entry(sp, &asoc->peer.transport_addr_list, + transports) { + if (sp == asoc->peer.primary_path) + printl("*"); + + if (sp->ipaddr.sa.sa_family == AF_INET) + printl("%pI4 ", &sp->ipaddr.v4.sin_addr); + else + printl("%pI6 ", &sp->ipaddr.v6.sin6_addr); + + printl("%2u %8u %8u %8u %8u %8u ", + sp->state, sp->cwnd, sp->ssthresh, + sp->flight_size, sp->partial_bytes_acked, + sp->pathmtu); + } + printl("\n"); + } + + jprobe_return(); + return 0; +} + +static struct jprobe sctp_recv_probe = { + .kp = { + .symbol_name = "sctp_sf_eat_sack_6_2", + }, + .entry = jsctp_sf_eat_sack, +}; + +static __init int sctpprobe_init(void) +{ + int ret = -ENOMEM; + + init_waitqueue_head(&sctpw.wait); + spin_lock_init(&sctpw.lock); + if (kfifo_alloc(&sctpw.fifo, bufsize, GFP_KERNEL)) + return ret; + + if (!proc_net_fops_create(&init_net, procname, S_IRUSR, + &sctpprobe_fops)) + goto free_kfifo; + + ret = register_jprobe(&sctp_recv_probe); + if (ret) + goto remove_proc; + + pr_info("probe registered (port=%d)\n", port); + + return 0; + +remove_proc: + proc_net_remove(&init_net, procname); +free_kfifo: + kfifo_free(&sctpw.fifo); + return ret; +} + +static __exit void sctpprobe_exit(void) +{ + kfifo_free(&sctpw.fifo); + proc_net_remove(&init_net, procname); + unregister_jprobe(&sctp_recv_probe); +} + +module_init(sctpprobe_init); +module_exit(sctpprobe_exit); |