freebsd-dev/sys/netpfil/ipfw/dn_aqm_codel.c
Conrad Meyer bcd8d3b805 dummynet: Use strlcpy to appease static checkers
Some dummynet modules used strcpy() to copy from a larger buffer
(dn_aqm->name) to a smaller buffer (dn_extra_parms->name).  It happens that
the lengths of the strings in the dn_aqm buffers were always hardcoded to be
smaller than the dn_extra_parms buffer ("CODEL", "PIE").

Use strlcpy() instead, to appease static checkers.  No functional change.

Reported by:	Coverity
CIDs:		1356163, 1356165
Sponsored by:	Dell EMC Isilon
2017-04-13 17:47:44 +00:00

445 lines
11 KiB
C

/*
* Codel - The Controlled-Delay Active Queue Management algorithm.
*
* $FreeBSD$
*
* Copyright (C) 2016 Centre for Advanced Internet Architectures,
* Swinburne University of Technology, Melbourne, Australia.
* Portions of this code were made possible in part by a gift from
* The Comcast Innovation Fund.
* Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au>
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */
#include <net/netisr.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip.h> /* ip_len, ip_off */
#include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */
#include <netinet/ip_fw.h>
#include <netinet/ip_dummynet.h>
#include <netinet/if_ether.h> /* various ether_* routines */
#include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */
#include <netinet6/ip6_var.h>
#include <netpfil/ipfw/dn_heap.h>
#ifdef NEW_AQM
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/ip_dn_private.h>
#include <netpfil/ipfw/dn_aqm.h>
#include <netpfil/ipfw/dn_aqm_codel.h>
#include <netpfil/ipfw/dn_sched.h>
#define DN_AQM_CODEL 1
static struct dn_aqm codel_desc;
/* default codel parameters */
struct dn_aqm_codel_parms codel_sysctl = {5000 * AQM_TIME_1US,
100000 * AQM_TIME_1US, 0};
static int
codel_sysctl_interval_handler(SYSCTL_HANDLER_ARGS)
{
int error;
long value;
value = codel_sysctl.interval;
value /= AQM_TIME_1US;
error = sysctl_handle_long(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (value < 1 || value > 100 * AQM_TIME_1S)
return (EINVAL);
codel_sysctl.interval = value * AQM_TIME_1US ;
return (0);
}
static int
codel_sysctl_target_handler(SYSCTL_HANDLER_ARGS)
{
int error;
long value;
value = codel_sysctl.target;
value /= AQM_TIME_1US;
error = sysctl_handle_long(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
D("%ld", value);
if (value < 1 || value > 5 * AQM_TIME_1S)
return (EINVAL);
codel_sysctl.target = value * AQM_TIME_1US ;
return (0);
}
/* defining Codel sysctl variables */
SYSBEGIN(f4)
SYSCTL_DECL(_net_inet);
SYSCTL_DECL(_net_inet_ip);
SYSCTL_DECL(_net_inet_ip_dummynet);
static SYSCTL_NODE(_net_inet_ip_dummynet, OID_AUTO,
codel, CTLFLAG_RW, 0, "CODEL");
#ifdef SYSCTL_NODE
SYSCTL_PROC(_net_inet_ip_dummynet_codel, OID_AUTO, target,
CTLTYPE_LONG | CTLFLAG_RW, NULL, 0,codel_sysctl_target_handler, "L",
"CoDel target in microsecond");
SYSCTL_PROC(_net_inet_ip_dummynet_codel, OID_AUTO, interval,
CTLTYPE_LONG | CTLFLAG_RW, NULL, 0, codel_sysctl_interval_handler, "L",
"CoDel interval in microsecond");
#endif
/* This function computes codel_interval/sqrt(count)
* Newton's method of approximation is used to compute 1/sqrt(count).
* http://betterexplained.com/articles/
* understanding-quakes-fast-inverse-square-root/
*/
aqm_time_t
control_law(struct codel_status *cst, struct dn_aqm_codel_parms *cprms,
aqm_time_t t)
{
uint32_t count;
uint64_t temp;
count = cst->count;
/* we don't calculate isqrt(1) to get more accurate result*/
if (count == 1) {
/* prepare isqrt (old guess) for the next iteration i.e. 1/sqrt(2)*/
cst->isqrt = (1UL<< FIX_POINT_BITS) * 7/10;
/* return time + isqrt(1)*interval */
return t + cprms->interval;
}
/* newguess = g(1.5 - 0.5*c*g^2)
* Multiplying both sides by 2 to make all the constants intergers
* newguess * 2 = g(3 - c*g^2) g=old guess, c=count
* So, newguess = newguess /2
* Fixed point operations are used here.
*/
/* Calculate g^2 */
temp = (uint32_t) cst->isqrt * cst->isqrt;
/* Calculate (3 - c*g^2) i.e. (3 - c * temp) */
temp = (3ULL<< (FIX_POINT_BITS*2)) - (count * temp);
/*
* Divide by 2 because we multiplied the original equation by two
* Also, we shift the result by 8 bits to prevent overflow.
* */
temp >>= (1 + 8);
/* Now, temp = (1.5 - 0.5*c*g^2)
* Calculate g (1.5 - 0.5*c*g^2) i.e. g * temp
*/
temp = (cst->isqrt * temp) >> (FIX_POINT_BITS + FIX_POINT_BITS - 8);
cst->isqrt = temp;
/* calculate codel_interval/sqrt(count) */
return t + ((cprms->interval * temp) >> FIX_POINT_BITS);
}
/*
* Extract a packet from the head of queue 'q'
* Return a packet or NULL if the queue is empty.
* Also extract packet's timestamp from mtag.
*/
struct mbuf *
codel_extract_head(struct dn_queue *q, aqm_time_t *pkt_ts)
{
struct m_tag *mtag;
struct mbuf *m = q->mq.head;
if (m == NULL)
return m;
q->mq.head = m->m_nextpkt;
/* Update stats */
update_stats(q, -m->m_pkthdr.len, 0);
if (q->ni.length == 0) /* queue is now idle */
q->q_time = dn_cfg.curr_time;
/* extract packet TS*/
mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
if (mtag == NULL) {
D("Codel timestamp mtag not found!");
*pkt_ts = 0;
} else {
*pkt_ts = *(aqm_time_t *)(mtag + 1);
m_tag_delete(m,mtag);
}
return m;
}
/*
* Enqueue a packet 'm' in queue 'q'
*/
static int
aqm_codel_enqueue(struct dn_queue *q, struct mbuf *m)
{
struct dn_fs *f;
uint64_t len;
struct codel_status *cst; /*codel status variables */
struct m_tag *mtag;
f = &(q->fs->fs);
len = m->m_pkthdr.len;
cst = q->aqm_status;
if(!cst) {
D("Codel queue is not initialized\n");
goto drop;
}
/* Finding maximum packet size */
// XXX we can get MTU from driver instead
if (len > cst->maxpkt_size)
cst->maxpkt_size = len;
/* check for queue size and drop the tail if exceed queue limit*/
if (f->flags & DN_QSIZE_BYTES) {
if ( q->ni.len_bytes > f->qsize)
goto drop;
}
else {
if ( q->ni.length >= f->qsize)
goto drop;
}
/* Add timestamp as mtag */
mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
if (mtag == NULL)
mtag = m_tag_alloc(MTAG_ABI_COMPAT, DN_AQM_MTAG_TS,
sizeof(aqm_time_t), M_NOWAIT);
if (mtag == NULL) {
m_freem(m);
goto drop;
}
*(aqm_time_t *)(mtag + 1) = AQM_UNOW;
m_tag_prepend(m, mtag);
mq_append(&q->mq, m);
update_stats(q, len, 0);
return (0);
drop:
update_stats(q, 0, 1);
FREE_PKT(m);
return (1);
}
/* Dequeue a pcaket from queue q */
static struct mbuf *
aqm_codel_dequeue(struct dn_queue *q)
{
return codel_dequeue(q);
}
/*
* initialize Codel for queue 'q'
* First allocate memory for codel status.
*/
static int
aqm_codel_init(struct dn_queue *q)
{
struct codel_status *cst;
if (!q->fs->aqmcfg) {
D("Codel is not configure!d");
return EINVAL;
}
q->aqm_status = malloc(sizeof(struct codel_status),
M_DUMMYNET, M_NOWAIT | M_ZERO);
if (q->aqm_status == NULL) {
D("Cannot allocate AQM_codel private data");
return ENOMEM ;
}
/* init codel status variables */
cst = q->aqm_status;
cst->dropping=0;
cst->first_above_time=0;
cst->drop_next_time=0;
cst->count=0;
cst->maxpkt_size = 500;
/* increase reference counters */
codel_desc.ref_count++;
return 0;
}
/*
* Clean up Codel status for queue 'q'
* Destroy memory allocated for codel status.
*/
static int
aqm_codel_cleanup(struct dn_queue *q)
{
if (q && q->aqm_status) {
free(q->aqm_status, M_DUMMYNET);
q->aqm_status = NULL;
/* decrease reference counters */
codel_desc.ref_count--;
}
else
D("Codel already cleaned up");
return 0;
}
/*
* Config codel parameters
* also allocate memory for codel configurations
*/
static int
aqm_codel_config(struct dn_fsk* fs, struct dn_extra_parms *ep, int len)
{
struct dn_aqm_codel_parms *ccfg;
int l = sizeof(struct dn_extra_parms);
if (len < l) {
D("invalid sched parms length got %d need %d", len, l);
return EINVAL;
}
/* we free the old cfg because maybe the original allocation
* not the same size as the new one (different AQM type).
*/
if (fs->aqmcfg) {
free(fs->aqmcfg, M_DUMMYNET);
fs->aqmcfg = NULL;
}
fs->aqmcfg = malloc(sizeof(struct dn_aqm_codel_parms),
M_DUMMYNET, M_NOWAIT | M_ZERO);
if (fs->aqmcfg== NULL) {
D("cannot allocate AQM_codel configuration parameters");
return ENOMEM;
}
/* configure codel parameters */
ccfg = fs->aqmcfg;
if (ep->par[0] < 0)
ccfg->target = codel_sysctl.target;
else
ccfg->target = ep->par[0] * AQM_TIME_1US;
if (ep->par[1] < 0)
ccfg->interval = codel_sysctl.interval;
else
ccfg->interval = ep->par[1] * AQM_TIME_1US;
if (ep->par[2] < 0)
ccfg->flags = 0;
else
ccfg->flags = ep->par[2];
/* bound codel configurations */
ccfg->target = BOUND_VAR(ccfg->target,1, 5 * AQM_TIME_1S);
ccfg->interval = BOUND_VAR(ccfg->interval,1, 5 * AQM_TIME_1S);
/* increase config reference counter */
codel_desc.cfg_ref_count++;
return 0;
}
/*
* Deconfigure Codel and free memory allocation
*/
static int
aqm_codel_deconfig(struct dn_fsk* fs)
{
if (fs && fs->aqmcfg) {
free(fs->aqmcfg, M_DUMMYNET);
fs->aqmcfg = NULL;
fs->aqmfp = NULL;
/* decrease config reference counter */
codel_desc.cfg_ref_count--;
}
return 0;
}
/*
* Retrieve Codel configuration parameters.
*/
static int
aqm_codel_getconfig(struct dn_fsk *fs, struct dn_extra_parms * ep)
{
struct dn_aqm_codel_parms *ccfg;
if (fs->aqmcfg) {
strlcpy(ep->name, codel_desc.name, sizeof(ep->name));
ccfg = fs->aqmcfg;
ep->par[0] = ccfg->target / AQM_TIME_1US;
ep->par[1] = ccfg->interval / AQM_TIME_1US;
ep->par[2] = ccfg->flags;
return 0;
}
return 1;
}
static struct dn_aqm codel_desc = {
_SI( .type = ) DN_AQM_CODEL,
_SI( .name = ) "CODEL",
_SI( .enqueue = ) aqm_codel_enqueue,
_SI( .dequeue = ) aqm_codel_dequeue,
_SI( .config = ) aqm_codel_config,
_SI( .getconfig = ) aqm_codel_getconfig,
_SI( .deconfig = ) aqm_codel_deconfig,
_SI( .init = ) aqm_codel_init,
_SI( .cleanup = ) aqm_codel_cleanup,
};
DECLARE_DNAQM_MODULE(dn_aqm_codel, &codel_desc);
#endif