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freebsd-skq/sys/netinet/siftr.c
brooks 8ba0807050 Make SIFTR work again after r342125 (D18443). 
Correct a logic error.

Only disable when already enabled or enable when disabled.

Submitted by:	Richard Scheffenegger
Reviewed by:	Cheng Cui
Obtained from:	Cheng Cui
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D18885
2019-01-18 21:46:38 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2007-2009
* Swinburne University of Technology, Melbourne, Australia.
* Copyright (c) 2009-2010, The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed at the Centre for Advanced
* Internet Architectures, Swinburne University of Technology, Melbourne,
* Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/******************************************************
* Statistical Information For TCP Research (SIFTR)
*
* A FreeBSD kernel module that adds very basic intrumentation to the
* TCP stack, allowing internal stats to be recorded to a log file
* for experimental, debugging and performance analysis purposes.
*
* SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
* working on the NewTCP research project at Swinburne University of
* Technology's Centre for Advanced Internet Architectures, Melbourne,
* Australia, which was made possible in part by a grant from the Cisco
* University Research Program Fund at Community Foundation Silicon Valley.
* More details are available at:
* http://caia.swin.edu.au/urp/newtcp/
*
* Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of
* the "Enhancing the FreeBSD TCP Implementation" project 2008-2009.
* More details are available at:
* http://www.freebsdfoundation.org/
* http://caia.swin.edu.au/freebsd/etcp09/
*
* Lawrence Stewart is the current maintainer, and all contact regarding
* SIFTR should be directed to him via email: lastewart@swin.edu.au
*
* Initial release date: June 2007
* Most recent update: September 2010
******************************************************/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/alq.h>
#include <sys/errno.h>
#include <sys/eventhandler.h>
#include <sys/hash.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sdt.h>
#include <sys/smp.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/pfil.h>
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_pcb.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/tcp_var.h>
#ifdef SIFTR_IPV6
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#endif /* SIFTR_IPV6 */
#include <machine/in_cksum.h>
/*
* Three digit version number refers to X.Y.Z where:
* X is the major version number
* Y is bumped to mark backwards incompatible changes
* Z is bumped to mark backwards compatible changes
*/
#define V_MAJOR 1
#define V_BACKBREAK 2
#define V_BACKCOMPAT 4
#define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
#define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
__XSTRING(V_BACKCOMPAT)
#define HOOK 0
#define UNHOOK 1
#define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
#define SYS_NAME "FreeBSD"
#define PACKET_TAG_SIFTR 100
#define PACKET_COOKIE_SIFTR 21749576
#define SIFTR_LOG_FILE_MODE 0644
#define SIFTR_DISABLE 0
#define SIFTR_ENABLE 1
/*
* Hard upper limit on the length of log messages. Bump this up if you add new
* data fields such that the line length could exceed the below value.
*/
#define MAX_LOG_MSG_LEN 200
/* XXX: Make this a sysctl tunable. */
#define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
/*
* 1 byte for IP version
* IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
* IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
*/
#ifdef SIFTR_IPV6
#define FLOW_KEY_LEN 37
#else
#define FLOW_KEY_LEN 13
#endif
#ifdef SIFTR_IPV6
#define SIFTR_IPMODE 6
#else
#define SIFTR_IPMODE 4
#endif
/* useful macros */
#define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16)
#define LOWER_SHORT(X) ((X) & 0x0000FFFF)
#define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24)
#define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
#define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8)
#define FOURTH_OCTET(X) ((X) & 0x000000FF)
static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
"SIFTR pkt_node struct");
static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
"SIFTR flow_hash_node struct");
/* Used as links in the pkt manager queue. */
struct pkt_node {
/* Timestamp of pkt as noted in the pfil hook. */
struct timeval tval;
/* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
uint8_t direction;
/* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
uint8_t ipver;
/* Hash of the pkt which triggered the log message. */
uint32_t hash;
/* Local/foreign IP address. */
#ifdef SIFTR_IPV6
uint32_t ip_laddr[4];
uint32_t ip_faddr[4];
#else
uint8_t ip_laddr[4];
uint8_t ip_faddr[4];
#endif
/* Local TCP port. */
uint16_t tcp_localport;
/* Foreign TCP port. */
uint16_t tcp_foreignport;
/* Congestion Window (bytes). */
u_long snd_cwnd;
/* Sending Window (bytes). */
u_long snd_wnd;
/* Receive Window (bytes). */
u_long rcv_wnd;
/* Unused (was: Bandwidth Controlled Window (bytes)). */
u_long snd_bwnd;
/* Slow Start Threshold (bytes). */
u_long snd_ssthresh;
/* Current state of the TCP FSM. */
int conn_state;
/* Max Segment Size (bytes). */
u_int max_seg_size;
/*
* Smoothed RTT stored as found in the TCP control block
* in units of (TCP_RTT_SCALE*hz).
*/
int smoothed_rtt;
/* Is SACK enabled? */
u_char sack_enabled;
/* Window scaling for snd window. */
u_char snd_scale;
/* Window scaling for recv window. */
u_char rcv_scale;
/* TCP control block flags. */
u_int flags;
/* Retransmit timeout length. */
int rxt_length;
/* Size of the TCP send buffer in bytes. */
u_int snd_buf_hiwater;
/* Current num bytes in the send socket buffer. */
u_int snd_buf_cc;
/* Size of the TCP receive buffer in bytes. */
u_int rcv_buf_hiwater;
/* Current num bytes in the receive socket buffer. */
u_int rcv_buf_cc;
/* Number of bytes inflight that we are waiting on ACKs for. */
u_int sent_inflight_bytes;
/* Number of segments currently in the reassembly queue. */
int t_segqlen;
/* Flowid for the connection. */
u_int flowid;
/* Flow type for the connection. */
u_int flowtype;
/* Link to next pkt_node in the list. */
STAILQ_ENTRY(pkt_node) nodes;
};
struct flow_hash_node
{
uint16_t counter;
uint8_t key[FLOW_KEY_LEN];
LIST_ENTRY(flow_hash_node) nodes;
};
struct siftr_stats
{
/* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
uint64_t n_in;
uint64_t n_out;
/* # pkts skipped due to failed malloc calls. */
uint32_t nskip_in_malloc;
uint32_t nskip_out_malloc;
/* # pkts skipped due to failed mtx acquisition. */
uint32_t nskip_in_mtx;
uint32_t nskip_out_mtx;
/* # pkts skipped due to failed inpcb lookups. */
uint32_t nskip_in_inpcb;
uint32_t nskip_out_inpcb;
/* # pkts skipped due to failed tcpcb lookups. */
uint32_t nskip_in_tcpcb;
uint32_t nskip_out_tcpcb;
/* # pkts skipped due to stack reinjection. */
uint32_t nskip_in_dejavu;
uint32_t nskip_out_dejavu;
};
DPCPU_DEFINE_STATIC(struct siftr_stats, ss);
static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
static unsigned int siftr_enabled = 0;
static unsigned int siftr_pkts_per_log = 1;
static unsigned int siftr_generate_hashes = 0;
/* static unsigned int siftr_binary_log = 0; */
static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
static u_long siftr_hashmask;
STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
LIST_HEAD(listhead, flow_hash_node) *counter_hash;
static int wait_for_pkt;
static struct alq *siftr_alq = NULL;
static struct mtx siftr_pkt_queue_mtx;
static struct mtx siftr_pkt_mgr_mtx;
static struct thread *siftr_pkt_manager_thr = NULL;
/*
* pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
* which we use as an index into this array.
*/
static char direction[3] = {'\0', 'i','o'};
/* Required function prototypes. */
static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
/* Declare the net.inet.siftr sysctl tree and populate it. */
SYSCTL_DECL(_net_inet_siftr);
SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
"siftr related settings");
SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
&siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
"switch siftr module operations on/off");
SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
&siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler,
"A", "file to save siftr log messages to");
SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
&siftr_pkts_per_log, 1,
"number of packets between generating a log message");
SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
&siftr_generate_hashes, 0,
"enable packet hash generation");
/* XXX: TODO
SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
&siftr_binary_log, 0,
"write log files in binary instead of ascii");
*/
/* Begin functions. */
static void
siftr_process_pkt(struct pkt_node * pkt_node)
{
struct flow_hash_node *hash_node;
struct listhead *counter_list;
struct siftr_stats *ss;
struct ale *log_buf;
uint8_t key[FLOW_KEY_LEN];
uint8_t found_match, key_offset;
hash_node = NULL;
ss = DPCPU_PTR(ss);
found_match = 0;
key_offset = 1;
/*
* Create the key that will be used to create a hash index
* into our hash table. Our key consists of:
* ipversion, localip, localport, foreignip, foreignport
*/
key[0] = pkt_node->ipver;
memcpy(key + key_offset, &pkt_node->ip_laddr,
sizeof(pkt_node->ip_laddr));
key_offset += sizeof(pkt_node->ip_laddr);
memcpy(key + key_offset, &pkt_node->tcp_localport,
sizeof(pkt_node->tcp_localport));
key_offset += sizeof(pkt_node->tcp_localport);
memcpy(key + key_offset, &pkt_node->ip_faddr,
sizeof(pkt_node->ip_faddr));
key_offset += sizeof(pkt_node->ip_faddr);
memcpy(key + key_offset, &pkt_node->tcp_foreignport,
sizeof(pkt_node->tcp_foreignport));
counter_list = counter_hash +
(hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
/*
* If the list is not empty i.e. the hash index has
* been used by another flow previously.
*/
if (LIST_FIRST(counter_list) != NULL) {
/*
* Loop through the hash nodes in the list.
* There should normally only be 1 hash node in the list,
* except if there have been collisions at the hash index
* computed by hash32_buf().
*/
LIST_FOREACH(hash_node, counter_list, nodes) {
/*
* Check if the key for the pkt we are currently
* processing is the same as the key stored in the
* hash node we are currently processing.
* If they are the same, then we've found the
* hash node that stores the counter for the flow
* the pkt belongs to.
*/
if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
found_match = 1;
break;
}
}
}
/* If this flow hash hasn't been seen before or we have a collision. */
if (hash_node == NULL || !found_match) {
/* Create a new hash node to store the flow's counter. */
hash_node = malloc(sizeof(struct flow_hash_node),
M_SIFTR_HASHNODE, M_WAITOK);
if (hash_node != NULL) {
/* Initialise our new hash node list entry. */
hash_node->counter = 0;
memcpy(hash_node->key, key, sizeof(key));
LIST_INSERT_HEAD(counter_list, hash_node, nodes);
} else {
/* Malloc failed. */
if (pkt_node->direction == PFIL_IN)
ss->nskip_in_malloc++;
else
ss->nskip_out_malloc++;
return;
}
} else if (siftr_pkts_per_log > 1) {
/*
* Taking the remainder of the counter divided
* by the current value of siftr_pkts_per_log
* and storing that in counter provides a neat
* way to modulate the frequency of log
* messages being written to the log file.
*/
hash_node->counter = (hash_node->counter + 1) %
siftr_pkts_per_log;
/*
* If we have not seen enough packets since the last time
* we wrote a log message for this connection, return.
*/
if (hash_node->counter > 0)
return;
}
log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
if (log_buf == NULL)
return; /* Should only happen if the ALQ is shutting down. */
#ifdef SIFTR_IPV6
pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
/* Construct an IPv6 log message. */
log_buf->ae_bytesused = snprintf(log_buf->ae_data,
MAX_LOG_MSG_LEN,
"%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
"%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
"%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
direction[pkt_node->direction],
pkt_node->hash,
pkt_node->tval.tv_sec,
pkt_node->tval.tv_usec,
UPPER_SHORT(pkt_node->ip_laddr[0]),
LOWER_SHORT(pkt_node->ip_laddr[0]),
UPPER_SHORT(pkt_node->ip_laddr[1]),
LOWER_SHORT(pkt_node->ip_laddr[1]),
UPPER_SHORT(pkt_node->ip_laddr[2]),
LOWER_SHORT(pkt_node->ip_laddr[2]),
UPPER_SHORT(pkt_node->ip_laddr[3]),
LOWER_SHORT(pkt_node->ip_laddr[3]),
ntohs(pkt_node->tcp_localport),
UPPER_SHORT(pkt_node->ip_faddr[0]),
LOWER_SHORT(pkt_node->ip_faddr[0]),
UPPER_SHORT(pkt_node->ip_faddr[1]),
LOWER_SHORT(pkt_node->ip_faddr[1]),
UPPER_SHORT(pkt_node->ip_faddr[2]),
LOWER_SHORT(pkt_node->ip_faddr[2]),
UPPER_SHORT(pkt_node->ip_faddr[3]),
LOWER_SHORT(pkt_node->ip_faddr[3]),
ntohs(pkt_node->tcp_foreignport),
pkt_node->snd_ssthresh,
pkt_node->snd_cwnd,
pkt_node->snd_bwnd,
pkt_node->snd_wnd,
pkt_node->rcv_wnd,
pkt_node->snd_scale,
pkt_node->rcv_scale,
pkt_node->conn_state,
pkt_node->max_seg_size,
pkt_node->smoothed_rtt,
pkt_node->sack_enabled,
pkt_node->flags,
pkt_node->rxt_length,
pkt_node->snd_buf_hiwater,
pkt_node->snd_buf_cc,
pkt_node->rcv_buf_hiwater,
pkt_node->rcv_buf_cc,
pkt_node->sent_inflight_bytes,
pkt_node->t_segqlen,
pkt_node->flowid,
pkt_node->flowtype);
} else { /* IPv4 packet */
pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
#endif /* SIFTR_IPV6 */
/* Construct an IPv4 log message. */
log_buf->ae_bytesused = snprintf(log_buf->ae_data,
MAX_LOG_MSG_LEN,
"%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
"%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
direction[pkt_node->direction],
pkt_node->hash,
(intmax_t)pkt_node->tval.tv_sec,
pkt_node->tval.tv_usec,
pkt_node->ip_laddr[0],
pkt_node->ip_laddr[1],
pkt_node->ip_laddr[2],
pkt_node->ip_laddr[3],
ntohs(pkt_node->tcp_localport),
pkt_node->ip_faddr[0],
pkt_node->ip_faddr[1],
pkt_node->ip_faddr[2],
pkt_node->ip_faddr[3],
ntohs(pkt_node->tcp_foreignport),
pkt_node->snd_ssthresh,
pkt_node->snd_cwnd,
pkt_node->snd_bwnd,
pkt_node->snd_wnd,
pkt_node->rcv_wnd,
pkt_node->snd_scale,
pkt_node->rcv_scale,
pkt_node->conn_state,
pkt_node->max_seg_size,
pkt_node->smoothed_rtt,
pkt_node->sack_enabled,
pkt_node->flags,
pkt_node->rxt_length,
pkt_node->snd_buf_hiwater,
pkt_node->snd_buf_cc,
pkt_node->rcv_buf_hiwater,
pkt_node->rcv_buf_cc,
pkt_node->sent_inflight_bytes,
pkt_node->t_segqlen,
pkt_node->flowid,
pkt_node->flowtype);
#ifdef SIFTR_IPV6
}
#endif
alq_post_flags(siftr_alq, log_buf, 0);
}
static void
siftr_pkt_manager_thread(void *arg)
{
STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
struct pkt_node *pkt_node, *pkt_node_temp;
uint8_t draining;
draining = 2;
mtx_lock(&siftr_pkt_mgr_mtx);
/* draining == 0 when queue has been flushed and it's safe to exit. */
while (draining) {
/*
* Sleep until we are signalled to wake because thread has
* been told to exit or until 1 tick has passed.
*/
mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
1);
/* Gain exclusive access to the pkt_node queue. */
mtx_lock(&siftr_pkt_queue_mtx);
/*
* Move pkt_queue to tmp_pkt_queue, which leaves
* pkt_queue empty and ready to receive more pkt_nodes.
*/
STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
/*
* We've finished making changes to the list. Unlock it
* so the pfil hooks can continue queuing pkt_nodes.
*/
mtx_unlock(&siftr_pkt_queue_mtx);
/*
* We can't hold a mutex whilst calling siftr_process_pkt
* because ALQ might sleep waiting for buffer space.
*/
mtx_unlock(&siftr_pkt_mgr_mtx);
/* Flush all pkt_nodes to the log file. */
STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
pkt_node_temp) {
siftr_process_pkt(pkt_node);
STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
free(pkt_node, M_SIFTR_PKTNODE);
}
KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
("SIFTR tmp_pkt_queue not empty after flush"));
mtx_lock(&siftr_pkt_mgr_mtx);
/*
* If siftr_exit_pkt_manager_thread gets set during the window
* where we are draining the tmp_pkt_queue above, there might
* still be pkts in pkt_queue that need to be drained.
* Allow one further iteration to occur after
* siftr_exit_pkt_manager_thread has been set to ensure
* pkt_queue is completely empty before we kill the thread.
*
* siftr_exit_pkt_manager_thread is set only after the pfil
* hooks have been removed, so only 1 extra iteration
* is needed to drain the queue.
*/
if (siftr_exit_pkt_manager_thread)
draining--;
}
mtx_unlock(&siftr_pkt_mgr_mtx);
/* Calls wakeup on this thread's struct thread ptr. */
kthread_exit();
}
static uint32_t
hash_pkt(struct mbuf *m, uint32_t offset)
{
uint32_t hash;
hash = 0;
while (m != NULL && offset > m->m_len) {
/*
* The IP packet payload does not start in this mbuf, so
* need to figure out which mbuf it starts in and what offset
* into the mbuf's data region the payload starts at.
*/
offset -= m->m_len;
m = m->m_next;
}
while (m != NULL) {
/* Ensure there is data in the mbuf */
if ((m->m_len - offset) > 0)
hash = hash32_buf(m->m_data + offset,
m->m_len - offset, hash);
m = m->m_next;
offset = 0;
}
return (hash);
}
/*
* Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
* it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
* Return value >0 means the caller should skip processing this mbuf.
*/
static inline int
siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
{
if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
!= NULL) {
if (dir == PFIL_IN)
ss->nskip_in_dejavu++;
else
ss->nskip_out_dejavu++;
return (1);
} else {
struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
PACKET_TAG_SIFTR, 0, M_NOWAIT);
if (tag == NULL) {
if (dir == PFIL_IN)
ss->nskip_in_malloc++;
else
ss->nskip_out_malloc++;
return (1);
}
m_tag_prepend(m, tag);
}
return (0);
}
/*
* Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
* otherwise.
*/
static inline struct inpcb *
siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
uint16_t dport, int dir, struct siftr_stats *ss)
{
struct inpcb *inp;
/* We need the tcbinfo lock. */
INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
if (dir == PFIL_IN)
inp = (ipver == INP_IPV4 ?
in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
:
#ifdef SIFTR_IPV6
in6_pcblookup(&V_tcbinfo,
&((struct ip6_hdr *)ip)->ip6_src, sport,
&((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
m->m_pkthdr.rcvif)
#else
NULL
#endif
);
else
inp = (ipver == INP_IPV4 ?
in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
:
#ifdef SIFTR_IPV6
in6_pcblookup(&V_tcbinfo,
&((struct ip6_hdr *)ip)->ip6_dst, dport,
&((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
m->m_pkthdr.rcvif)
#else
NULL
#endif
);
/* If we can't find the inpcb, bail. */
if (inp == NULL) {
if (dir == PFIL_IN)
ss->nskip_in_inpcb++;
else
ss->nskip_out_inpcb++;
}
return (inp);
}
static inline void
siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
int ipver, int dir, int inp_locally_locked)
{
#ifdef SIFTR_IPV6
if (ipver == INP_IPV4) {
pn->ip_laddr[3] = inp->inp_laddr.s_addr;
pn->ip_faddr[3] = inp->inp_faddr.s_addr;
#else
*((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
*((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
#endif
#ifdef SIFTR_IPV6
} else {
pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
}
#endif
pn->tcp_localport = inp->inp_lport;
pn->tcp_foreignport = inp->inp_fport;
pn->snd_cwnd = tp->snd_cwnd;
pn->snd_wnd = tp->snd_wnd;
pn->rcv_wnd = tp->rcv_wnd;
pn->snd_bwnd = 0; /* Unused, kept for compat. */
pn->snd_ssthresh = tp->snd_ssthresh;
pn->snd_scale = tp->snd_scale;
pn->rcv_scale = tp->rcv_scale;
pn->conn_state = tp->t_state;
pn->max_seg_size = tp->t_maxseg;
pn->smoothed_rtt = tp->t_srtt;
pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
pn->flags = tp->t_flags;
pn->rxt_length = tp->t_rxtcur;
pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
pn->t_segqlen = tp->t_segqlen;
pn->flowid = inp->inp_flowid;
pn->flowtype = inp->inp_flowtype;
/* We've finished accessing the tcb so release the lock. */
if (inp_locally_locked)
INP_RUNLOCK(inp);
pn->ipver = ipver;
pn->direction = dir;
/*
* Significantly more accurate than using getmicrotime(), but slower!
* Gives true microsecond resolution at the expense of a hit to
* maximum pps throughput processing when SIFTR is loaded and enabled.
*/
microtime(&pn->tval);
TCP_PROBE1(siftr, &pn);
}
/*
* pfil hook that is called for each IPv4 packet making its way through the
* stack in either direction.
* The pfil subsystem holds a non-sleepable mutex somewhere when
* calling our hook function, so we can't sleep at all.
* It's very important to use the M_NOWAIT flag with all function calls
* that support it so that they won't sleep, otherwise you get a panic.
*/
static int
siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
struct inpcb *inp)
{
struct pkt_node *pn;
struct ip *ip;
struct tcphdr *th;
struct tcpcb *tp;
struct siftr_stats *ss;
unsigned int ip_hl;
int inp_locally_locked;
inp_locally_locked = 0;
ss = DPCPU_PTR(ss);
/*
* m_pullup is not required here because ip_{input|output}
* already do the heavy lifting for us.
*/
ip = mtod(*m, struct ip *);
/* Only continue processing if the packet is TCP. */
if (ip->ip_p != IPPROTO_TCP)
goto ret;
/*
* If a kernel subsystem reinjects packets into the stack, our pfil
* hook will be called multiple times for the same packet.
* Make sure we only process unique packets.
*/
if (siftr_chkreinject(*m, dir, ss))
goto ret;
if (dir == PFIL_IN)
ss->n_in++;
else
ss->n_out++;
/*
* Create a tcphdr struct starting at the correct offset
* in the IP packet. ip->ip_hl gives the ip header length
* in 4-byte words, so multiply it to get the size in bytes.
*/
ip_hl = (ip->ip_hl << 2);
th = (struct tcphdr *)((caddr_t)ip + ip_hl);
/*
* If the pfil hooks don't provide a pointer to the
* inpcb, we need to find it ourselves and lock it.
*/
if (!inp) {
/* Find the corresponding inpcb for this pkt. */
inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
th->th_dport, dir, ss);
if (inp == NULL)
goto ret;
else
inp_locally_locked = 1;
}
INP_LOCK_ASSERT(inp);
/* Find the TCP control block that corresponds with this packet */
tp = intotcpcb(inp);
/*
* If we can't find the TCP control block (happens occasionaly for a
* packet sent during the shutdown phase of a TCP connection),
* or we're in the timewait state, bail
*/
if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
if (dir == PFIL_IN)
ss->nskip_in_tcpcb++;
else
ss->nskip_out_tcpcb++;
goto inp_unlock;
}
pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
if (pn == NULL) {
if (dir == PFIL_IN)
ss->nskip_in_malloc++;
else
ss->nskip_out_malloc++;
goto inp_unlock;
}
siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
if (siftr_generate_hashes) {
if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
/*
* For outbound packets, the TCP checksum isn't
* calculated yet. This is a problem for our packet
* hashing as the receiver will calc a different hash
* to ours if we don't include the correct TCP checksum
* in the bytes being hashed. To work around this
* problem, we manually calc the TCP checksum here in
* software. We unset the CSUM_TCP flag so the lower
* layers don't recalc it.
*/
(*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
/*
* Calculate the TCP checksum in software and assign
* to correct TCP header field, which will follow the
* packet mbuf down the stack. The trick here is that
* tcp_output() sets th->th_sum to the checksum of the
* pseudo header for us already. Because of the nature
* of the checksumming algorithm, we can sum over the
* entire IP payload (i.e. TCP header and data), which
* will include the already calculated pseduo header
* checksum, thus giving us the complete TCP checksum.
*
* To put it in simple terms, if checksum(1,2,3,4)=10,
* then checksum(1,2,3,4,5) == checksum(10,5).
* This property is what allows us to "cheat" and
* checksum only the IP payload which has the TCP
* th_sum field populated with the pseudo header's
* checksum, and not need to futz around checksumming
* pseudo header bytes and TCP header/data in one hit.
* Refer to RFC 1071 for more info.
*
* NB: in_cksum_skip(struct mbuf *m, int len, int skip)
* in_cksum_skip 2nd argument is NOT the number of
* bytes to read from the mbuf at "skip" bytes offset
* from the start of the mbuf (very counter intuitive!).
* The number of bytes to read is calculated internally
* by the function as len-skip i.e. to sum over the IP
* payload (TCP header + data) bytes, it is INCORRECT
* to call the function like this:
* in_cksum_skip(at, ip->ip_len - offset, offset)
* Rather, it should be called like this:
* in_cksum_skip(at, ip->ip_len, offset)
* which means read "ip->ip_len - offset" bytes from
* the mbuf cluster "at" at offset "offset" bytes from
* the beginning of the "at" mbuf's data pointer.
*/
th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
ip_hl);
}
/*
* XXX: Having to calculate the checksum in software and then
* hash over all bytes is really inefficient. Would be nice to
* find a way to create the hash and checksum in the same pass
* over the bytes.
*/
pn->hash = hash_pkt(*m, ip_hl);
}
mtx_lock(&siftr_pkt_queue_mtx);
STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
mtx_unlock(&siftr_pkt_queue_mtx);
goto ret;
inp_unlock:
if (inp_locally_locked)
INP_RUNLOCK(inp);
ret:
/* Returning 0 ensures pfil will not discard the pkt */
return (0);
}
#ifdef SIFTR_IPV6
static int
siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
struct inpcb *inp)
{
struct pkt_node *pn;
struct ip6_hdr *ip6;
struct tcphdr *th;
struct tcpcb *tp;
struct siftr_stats *ss;
unsigned int ip6_hl;
int inp_locally_locked;
inp_locally_locked = 0;
ss = DPCPU_PTR(ss);
/*
* m_pullup is not required here because ip6_{input|output}
* already do the heavy lifting for us.
*/
ip6 = mtod(*m, struct ip6_hdr *);
/*
* Only continue processing if the packet is TCP
* XXX: We should follow the next header fields
* as shown on Pg 6 RFC 2460, but right now we'll
* only check pkts that have no extension headers.
*/
if (ip6->ip6_nxt != IPPROTO_TCP)
goto ret6;
/*
* If a kernel subsystem reinjects packets into the stack, our pfil
* hook will be called multiple times for the same packet.
* Make sure we only process unique packets.
*/
if (siftr_chkreinject(*m, dir, ss))
goto ret6;
if (dir == PFIL_IN)
ss->n_in++;
else
ss->n_out++;
ip6_hl = sizeof(struct ip6_hdr);
/*
* Create a tcphdr struct starting at the correct offset
* in the ipv6 packet. ip->ip_hl gives the ip header length
* in 4-byte words, so multiply it to get the size in bytes.
*/
th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
/*
* For inbound packets, the pfil hooks don't provide a pointer to the
* inpcb, so we need to find it ourselves and lock it.
*/
if (!inp) {
/* Find the corresponding inpcb for this pkt. */
inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
th->th_sport, th->th_dport, dir, ss);
if (inp == NULL)
goto ret6;
else
inp_locally_locked = 1;
}
/* Find the TCP control block that corresponds with this packet. */
tp = intotcpcb(inp);
/*
* If we can't find the TCP control block (happens occasionaly for a
* packet sent during the shutdown phase of a TCP connection),
* or we're in the timewait state, bail.
*/
if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
if (dir == PFIL_IN)
ss->nskip_in_tcpcb++;
else
ss->nskip_out_tcpcb++;
goto inp_unlock6;
}
pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
if (pn == NULL) {
if (dir == PFIL_IN)
ss->nskip_in_malloc++;
else
ss->nskip_out_malloc++;
goto inp_unlock6;
}
siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
/* XXX: Figure out how to generate hashes for IPv6 packets. */
mtx_lock(&siftr_pkt_queue_mtx);
STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
mtx_unlock(&siftr_pkt_queue_mtx);
goto ret6;
inp_unlock6:
if (inp_locally_locked)
INP_RUNLOCK(inp);
ret6:
/* Returning 0 ensures pfil will not discard the pkt. */
return (0);
}
#endif /* #ifdef SIFTR_IPV6 */
static int
siftr_pfil(int action)
{
struct pfil_head *pfh_inet;
#ifdef SIFTR_IPV6
struct pfil_head *pfh_inet6;
#endif
VNET_ITERATOR_DECL(vnet_iter);
VNET_LIST_RLOCK();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
#ifdef SIFTR_IPV6
pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
#endif
if (action == HOOK) {
pfil_add_hook(siftr_chkpkt, NULL,
PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
#ifdef SIFTR_IPV6
pfil_add_hook(siftr_chkpkt6, NULL,
PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
#endif
} else if (action == UNHOOK) {
pfil_remove_hook(siftr_chkpkt, NULL,
PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
#ifdef SIFTR_IPV6
pfil_remove_hook(siftr_chkpkt6, NULL,
PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
#endif
}
CURVNET_RESTORE();
}
VNET_LIST_RUNLOCK();
return (0);
}
static int
siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
{
struct alq *new_alq;
int error;
error = sysctl_handle_string(oidp, arg1, arg2, req);
/* Check for error or same filename */
if (error != 0 || req->newptr == NULL ||
strncmp(siftr_logfile, arg1, arg2) == 0)
goto done;
/* Filname changed */
error = alq_open(&new_alq, arg1, curthread->td_ucred,
SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
if (error != 0)
goto done;
/*
* If disabled, siftr_alq == NULL so we simply close
* the alq as we've proved it can be opened.
* If enabled, close the existing alq and switch the old
* for the new.
*/
if (siftr_alq == NULL) {
alq_close(new_alq);
} else {
alq_close(siftr_alq);
siftr_alq = new_alq;
}
/* Update filename upon success */
strlcpy(siftr_logfile, arg1, arg2);
done:
return (error);
}
static int
siftr_manage_ops(uint8_t action)
{
struct siftr_stats totalss;
struct timeval tval;
struct flow_hash_node *counter, *tmp_counter;
struct sbuf *s;
int i, key_index, error;
uint32_t bytes_to_write, total_skipped_pkts;
uint16_t lport, fport;
uint8_t *key, ipver __unused;
#ifdef SIFTR_IPV6
uint32_t laddr[4];
uint32_t faddr[4];
#else
uint8_t laddr[4];
uint8_t faddr[4];
#endif
error = 0;
total_skipped_pkts = 0;
/* Init an autosizing sbuf that initially holds 200 chars. */
if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
return (-1);
if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) {
/*
* Create our alq
* XXX: We should abort if alq_open fails!
*/
alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
STAILQ_INIT(&pkt_queue);
DPCPU_ZERO(ss);
siftr_exit_pkt_manager_thread = 0;
kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
&siftr_pkt_manager_thr, RFNOWAIT, 0,
"siftr_pkt_manager_thr");
siftr_pfil(HOOK);
microtime(&tval);
sbuf_printf(s,
"enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
"siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
"sysver=%u\tipmode=%u\n",
(intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
sbuf_finish(s);
alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
} else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
/*
* Remove the pfil hook functions. All threads currently in
* the hook functions are allowed to exit before siftr_pfil()
* returns.
*/
siftr_pfil(UNHOOK);
/* This will block until the pkt manager thread unlocks it. */
mtx_lock(&siftr_pkt_mgr_mtx);
/* Tell the pkt manager thread that it should exit now. */
siftr_exit_pkt_manager_thread = 1;
/*
* Wake the pkt_manager thread so it realises that
* siftr_exit_pkt_manager_thread == 1 and exits gracefully.
* The wakeup won't be delivered until we unlock
* siftr_pkt_mgr_mtx so this isn't racy.
*/
wakeup(&wait_for_pkt);
/* Wait for the pkt_manager thread to exit. */
mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
"thrwait", 0);
siftr_pkt_manager_thr = NULL;
mtx_unlock(&siftr_pkt_mgr_mtx);
totalss.n_in = DPCPU_VARSUM(ss, n_in);
totalss.n_out = DPCPU_VARSUM(ss, n_out);
totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
total_skipped_pkts = totalss.nskip_in_malloc +
totalss.nskip_out_malloc + totalss.nskip_in_mtx +
totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
totalss.nskip_out_inpcb;
microtime(&tval);
sbuf_printf(s,
"disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
"num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
"total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
"num_outbound_skipped_pkts_malloc=%u\t"
"num_inbound_skipped_pkts_mtx=%u\t"
"num_outbound_skipped_pkts_mtx=%u\t"
"num_inbound_skipped_pkts_tcpcb=%u\t"
"num_outbound_skipped_pkts_tcpcb=%u\t"
"num_inbound_skipped_pkts_inpcb=%u\t"
"num_outbound_skipped_pkts_inpcb=%u\t"
"total_skipped_tcp_pkts=%u\tflow_list=",
(intmax_t)tval.tv_sec,
tval.tv_usec,
(uintmax_t)totalss.n_in,
(uintmax_t)totalss.n_out,
(uintmax_t)(totalss.n_in + totalss.n_out),
totalss.nskip_in_malloc,
totalss.nskip_out_malloc,
totalss.nskip_in_mtx,
totalss.nskip_out_mtx,
totalss.nskip_in_tcpcb,
totalss.nskip_out_tcpcb,
totalss.nskip_in_inpcb,
totalss.nskip_out_inpcb,
total_skipped_pkts);
/*
* Iterate over the flow hash, printing a summary of each
* flow seen and freeing any malloc'd memory.
* The hash consists of an array of LISTs (man 3 queue).
*/
for (i = 0; i <= siftr_hashmask; i++) {
LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
tmp_counter) {
key = counter->key;
key_index = 1;
ipver = key[0];
memcpy(laddr, key + key_index, sizeof(laddr));
key_index += sizeof(laddr);
memcpy(&lport, key + key_index, sizeof(lport));
key_index += sizeof(lport);
memcpy(faddr, key + key_index, sizeof(faddr));
key_index += sizeof(faddr);
memcpy(&fport, key + key_index, sizeof(fport));
#ifdef SIFTR_IPV6
laddr[3] = ntohl(laddr[3]);
faddr[3] = ntohl(faddr[3]);
if (ipver == INP_IPV6) {
laddr[0] = ntohl(laddr[0]);
laddr[1] = ntohl(laddr[1]);
laddr[2] = ntohl(laddr[2]);
faddr[0] = ntohl(faddr[0]);
faddr[1] = ntohl(faddr[1]);
faddr[2] = ntohl(faddr[2]);
sbuf_printf(s,
"%x:%x:%x:%x:%x:%x:%x:%x;%u-"
"%x:%x:%x:%x:%x:%x:%x:%x;%u,",
UPPER_SHORT(laddr[0]),
LOWER_SHORT(laddr[0]),
UPPER_SHORT(laddr[1]),
LOWER_SHORT(laddr[1]),
UPPER_SHORT(laddr[2]),
LOWER_SHORT(laddr[2]),
UPPER_SHORT(laddr[3]),
LOWER_SHORT(laddr[3]),
ntohs(lport),
UPPER_SHORT(faddr[0]),
LOWER_SHORT(faddr[0]),
UPPER_SHORT(faddr[1]),
LOWER_SHORT(faddr[1]),
UPPER_SHORT(faddr[2]),
LOWER_SHORT(faddr[2]),
UPPER_SHORT(faddr[3]),
LOWER_SHORT(faddr[3]),
ntohs(fport));
} else {
laddr[0] = FIRST_OCTET(laddr[3]);
laddr[1] = SECOND_OCTET(laddr[3]);
laddr[2] = THIRD_OCTET(laddr[3]);
laddr[3] = FOURTH_OCTET(laddr[3]);
faddr[0] = FIRST_OCTET(faddr[3]);
faddr[1] = SECOND_OCTET(faddr[3]);
faddr[2] = THIRD_OCTET(faddr[3]);
faddr[3] = FOURTH_OCTET(faddr[3]);
#endif
sbuf_printf(s,
"%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
laddr[0],
laddr[1],
laddr[2],
laddr[3],
ntohs(lport),
faddr[0],
faddr[1],
faddr[2],
faddr[3],
ntohs(fport));
#ifdef SIFTR_IPV6
}
#endif
free(counter, M_SIFTR_HASHNODE);
}
LIST_INIT(counter_hash + i);
}
sbuf_printf(s, "\n");
sbuf_finish(s);
i = 0;
do {
bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
i += bytes_to_write;
} while (i < sbuf_len(s));
alq_close(siftr_alq);
siftr_alq = NULL;
} else
error = EINVAL;
sbuf_delete(s);
/*
* XXX: Should be using ret to check if any functions fail
* and set error appropriately
*/
return (error);
}
static int
siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
{
int error;
uint32_t new;
new = siftr_enabled;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (new > 1)
return (EINVAL);
else if (new != siftr_enabled) {
if ((error = siftr_manage_ops(new)) == 0) {
siftr_enabled = new;
} else {
siftr_manage_ops(SIFTR_DISABLE);
}
}
}
return (error);
}
static void
siftr_shutdown_handler(void *arg)
{
if (siftr_enabled == 1) {
siftr_manage_ops(SIFTR_DISABLE);
}
}
/*
* Module is being unloaded or machine is shutting down. Take care of cleanup.
*/
static int
deinit_siftr(void)
{
/* Cleanup. */
siftr_manage_ops(SIFTR_DISABLE);
hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
mtx_destroy(&siftr_pkt_queue_mtx);
mtx_destroy(&siftr_pkt_mgr_mtx);
return (0);
}
/*
* Module has just been loaded into the kernel.
*/
static int
init_siftr(void)
{
EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
SHUTDOWN_PRI_FIRST);
/* Initialise our flow counter hash table. */
counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
&siftr_hashmask);
mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
/* Print message to the user's current terminal. */
uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
" http://caia.swin.edu.au/urp/newtcp\n\n",
MODVERSION_STR);
return (0);
}
/*
* This is the function that is called to load and unload the module.
* When the module is loaded, this function is called once with
* "what" == MOD_LOAD
* When the module is unloaded, this function is called twice with
* "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
* When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
* this function is called once with "what" = MOD_SHUTDOWN
* When the system is shut down, the handler isn't called until the very end
* of the shutdown sequence i.e. after the disks have been synced.
*/
static int
siftr_load_handler(module_t mod, int what, void *arg)
{
int ret;
switch (what) {
case MOD_LOAD:
ret = init_siftr();
break;
case MOD_QUIESCE:
case MOD_SHUTDOWN:
ret = deinit_siftr();
break;
case MOD_UNLOAD:
ret = 0;
break;
default:
ret = EINVAL;
break;
}
return (ret);
}
static moduledata_t siftr_mod = {
.name = "siftr",
.evhand = siftr_load_handler,
};
/*
* Param 1: name of the kernel module
* Param 2: moduledata_t struct containing info about the kernel module
* and the execution entry point for the module
* Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
* Defines the module initialisation order
* Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
* Defines the initialisation order of this kld relative to others
* within the same subsystem as defined by param 3
*/
DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
MODULE_DEPEND(siftr, alq, 1, 1, 1);
MODULE_VERSION(siftr, MODVERSION);
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