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freebsd-dev/sys/netinet/siftr.c
Robert Watson fa046d8774 Decompose the current single inpcbinfo lock into two locks: 
- The existing ipi_lock continues to protect the global inpcb list and
  inpcb counter.  This lock is now relegated to a small number of
  allocation and free operations, and occasional operations that walk
  all connections (including, awkwardly, certain UDP multicast receive
  operations -- something to revisit).

- A new ipi_hash_lock protects the two inpcbinfo hash tables for
  looking up connections and bound sockets, manipulated using new
  INP_HASH_*() macros.  This lock, combined with inpcb locks, protects
  the 4-tuple address space.

Unlike the current ipi_lock, ipi_hash_lock follows the individual inpcb
connection locks, so may be acquired while manipulating a connection on
which a lock is already held, avoiding the need to acquire the inpcbinfo
lock preemptively when a binding change might later be required.  As a
result, however, lookup operations necessarily go through a reference
acquire while holding the lookup lock, later acquiring an inpcb lock --
if required.

A new function in_pcblookup() looks up connections, and accepts flags
indicating how to return the inpcb.  Due to lock order changes, callers
no longer need acquire locks before performing a lookup: the lookup
routine will acquire the ipi_hash_lock as needed.  In the future, it will
also be able to use alternative lookup and locking strategies
transparently to callers, such as pcbgroup lookup.  New lookup flags are,
supplementing the existing INPLOOKUP_WILDCARD flag:

  INPLOOKUP_RLOCKPCB - Acquire a read lock on the returned inpcb
  INPLOOKUP_WLOCKPCB - Acquire a write lock on the returned inpcb

Callers must pass exactly one of these flags (for the time being).

Some notes:

- All protocols are updated to work within the new regime; especially,
  TCP, UDPv4, and UDPv6.  pcbinfo ipi_lock acquisitions are largely
  eliminated, and global hash lock hold times are dramatically reduced
  compared to previous locking.
- The TCP syncache still relies on the pcbinfo lock, something that we
  may want to revisit.
- Support for reverting to the FreeBSD 7.x locking strategy in TCP input
  is no longer available -- hash lookup locks are now held only very
  briefly during inpcb lookup, rather than for potentially extended
  periods.  However, the pcbinfo ipi_lock will still be acquired if a
  connection state might change such that a connection is added or
  removed.
- Raw IP sockets continue to use the pcbinfo ipi_lock for protection,
  due to maintaining their own hash tables.
- The interface in6_pcblookup_hash_locked() is maintained, which allows
  callers to acquire hash locks and perform one or more lookups atomically
  with 4-tuple allocation: this is required only for TCPv6, as there is no
  in6_pcbconnect_setup(), which there should be.
- UDPv6 locking remains significantly more conservative than UDPv4
  locking, which relates to source address selection.  This needs
  attention, as it likely significantly reduces parallelism in this code
  for multithreaded socket use (such as in BIND).
- In the UDPv4 and UDPv6 multicast cases, we need to revisit locking
  somewhat, as they relied on ipi_lock to stablise 4-tuple matches, which
  is no longer sufficient.  A second check once the inpcb lock is held
  should do the trick, keeping the general case from requiring the inpcb
  lock for every inpcb visited.
- This work reminds us that we need to revisit locking of the v4/v6 flags,
  which may be accessed lock-free both before and after this change.
- Right now, a single lock name is used for the pcbhash lock -- this is
  undesirable, and probably another argument is required to take care of
  this (or a char array name field in the pcbinfo?).

This is not an MFC candidate for 8.x due to its impact on lookup and
locking semantics.  It's possible some of these issues could be worked
around with compatibility wrappers, if necessary.

Reviewed by:    bz
Sponsored by:   Juniper Networks, Inc.
2011-05-30 09:43:55 +00:00

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/*-
* 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/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/smp.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <net/if.h>
#include <net/pfil.h>
#include <netinet/in.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 CAST_PTR_INT(X) (*((int*)(X)))
#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;
/* 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;
};
static DPCPU_DEFINE(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 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, sizeof(siftr_logfile), &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\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);
} 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\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);
#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_UNLOCK_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 = inp->inp_socket->so_snd.sb_cc;
pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
pn->rcv_buf_cc = inp->inp_socket->so_rcv.sb_cc;
pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
pn->t_segqlen = tp->t_segqlen;
/* 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);
}
/*
* 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, 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;
if (req->newptr == NULL)
goto skip;
/* If old filename and new filename are different. */
if (strncmp(siftr_logfile, (char *)req->newptr, PATH_MAX)) {
error = alq_open(&new_alq, req->newptr, curthread->td_ucred,
SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
/* Bail if unable to create new alq. */
if (error)
return (1);
/*
* 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;
}
}
skip:
return (sysctl_handle_string(oidp, arg1, arg2, req));
}
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, ret, error;
uint32_t bytes_to_write, total_skipped_pkts;
uint16_t lport, fport;
uint8_t *key, ipver;
#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) {
/*
* 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;
ret = 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;
}
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)
{
if (req->newptr == NULL)
goto skip;
/* If the value passed in isn't 0 or 1, return an error. */
if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
return (1);
/* If we are changing state (0 to 1 or 1 to 0). */
if (CAST_PTR_INT(req->newptr) != siftr_enabled )
if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
siftr_manage_ops(SIFTR_DISABLE);
return (1);
}
skip:
return (sysctl_handle_int(oidp, arg1, arg2, req));
}
static void
siftr_shutdown_handler(void *arg)
{
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_SMP, SI_ORDER_ANY);
MODULE_DEPEND(siftr, alq, 1, 1, 1);
MODULE_VERSION(siftr, MODVERSION);
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