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freebsd-skq/sys/netinet/ip_dummynet.c

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/*
* Copyright (c) 1998 Luigi Rizzo
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*
* $Id: ip_dummynet.c,v 1.1 1998/09/12 22:03:20 luigi Exp $
*/
/*
* This module implements IP dummynet, a bandwidth limiter/delay emulator
* used in conjunction with the ipfw package.
*
* Changes:
*
* 980821: changed conventions in the queueing logic
* packets passed from dummynet to ip_in/out are prepended with
* a vestigial mbuf type MT_DUMMYNET which contains a pointer
* to the matching rule.
* ip_input/output will extract the parameters, free the vestigial mbuf,
* and do the processing.
*
* 980519: fixed behaviour when deleting rules.
* 980518: added splimp()/splx() to protect against races
* 980513: initial release
*/
/* include files marked with XXX are probably not needed */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h> /* XXX */
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_fw.h>
#include <netinet/ip_dummynet.h>
#ifdef BRIDGE
#include <netinet/if_ether.h> /* for struct arpcom */
#include <net/bridge.h>
#endif
static struct dn_pipe *all_pipes = NULL ; /* list of all pipes */
static int dn_debug = 0 ; /* verbose */
static int dn_calls = 0 ; /* number of calls */
static int dn_idle = 1;
#ifdef SYSCTL_NODE
SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW, 0, "Dummynet");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, CTLFLAG_RW, &dn_debug, 0, "");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, calls, CTLFLAG_RD, &dn_calls, 0, "");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, idle, CTLFLAG_RD, &dn_idle, 0, "");
#endif
static int ip_dn_ctl(struct sockopt *sopt);
static void dummynet(void);
static void dn_restart(void);
static void dn_move(struct dn_pipe *pipe, int immediate);
/*
* the following is needed when deleting a pipe, because rules can
* hold references to the pipe.
*/
extern LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain;
/*
* invoked to reschedule the periodic task if necessary.
* Should only be called when dn_idle = 1 ;
*/
static void
dn_restart()
{
struct dn_pipe *pipe;
if (!dn_idle)
return;
for (pipe = all_pipes ; pipe ; pipe = pipe->next ) {
/* if there any pipe that needs work, restart */
if (pipe->r.head || pipe->p.head || pipe->numbytes < 0 ) {
dn_idle = 0;
timeout(dummynet, (caddr_t)NULL, 1);
return ;
}
}
}
/*
* move packets from R-queue to P-queue
*/
static void
dn_move(struct dn_pipe *pipe, int immediate)
{
struct dn_pkt *tmp, *pkt;
/*
* consistency check, should catch new pipes which are
* not initialized properly.
*/
if ( pipe->p.head == NULL &&
pipe->ticks_from_last_insert != pipe->delay) {
printf("Warning, empty pipe and delay %d (should be %d)\n",
pipe->ticks_from_last_insert, pipe->delay);
pipe->ticks_from_last_insert = pipe->delay;
}
/* this ought to go in dn_dequeue() */
if (!immediate && pipe->ticks_from_last_insert < pipe->delay)
pipe->ticks_from_last_insert++;
if ( pkt = pipe->r.head ) {
/*
* Move at most numbytes bytes from src and move to dst.
* delay is set to ticks_from_last_insert, which
* is reset after the first insertion;
*/
while ( pkt ) {
struct ip *ip=mtod(pkt->dn_m, struct ip *);
/*
* queue limitation: pass packets down if the len is
* such that the pkt would go out before the next tick.
*/
if (pipe->bandwidth) {
if (pipe->numbytes < ip->ip_len)
break;
pipe->numbytes -= ip->ip_len;
}
pipe->r_len--; /* elements in queue */
pipe->r_len_bytes -= ip->ip_len ;
/*
* to add delay jitter, must act here. A lower value
* (bounded to 0) means lower delay.
*/
pkt->delay = pipe->ticks_from_last_insert;
pipe->ticks_from_last_insert = 0;
/* compensate the decrement done next in dn_dequeue */
if (!immediate && pkt->delay >0 && pipe->p.head==NULL)
pkt->delay++;
if (pipe->p.head == NULL)
pipe->p.head = pkt;
else
(struct dn_pkt *)pipe->p.tail->dn_next = pkt;
pipe->p.tail = pkt;
pkt = (struct dn_pkt *)pkt->dn_next;
pipe->p.tail->dn_next = NULL;
}
pipe->r.head = pkt;
/*** XXX just a sanity check */
if ( ( pkt == NULL && pipe->r_len != 0) ||
( pkt != NULL && pipe->r_len == 0) )
printf("-- Warning, pipe head %x len %d\n",
pkt, pipe->r_len);
}
/*
* deliver packets downstream after the delay in the P-queue.
*/
if (pipe->p.head == NULL)
return;
if (!immediate)
pipe->p.head->delay--;
while ( (pkt = pipe->p.head) && pkt->delay < 1) {
/*
* first unlink, then call procedures since ip_input()
* can result in a call to ip_output cnd viceversa,
* thus causing nested calls
*/
pipe->p.head = (struct dn_pkt *) pkt->dn_next ;
/*
* the trick to avoid flow-id settings here is to prepend a
* vestigial mbuf to the packet, with the following values:
* m_type = MT_DUMMYNET
* m_next = the actual mbuf to be processed by ip_input/output
* m_data = the matching rule
* The vestigial element is the same memory area used by
* the dn_pkt, and IS FREED IN ip_input/ip_output. IT IS
* NOT A REAL MBUF, just a block of memory acquired with malloc().
*/
switch (pkt->dn_dir) {
case DN_TO_IP_OUT: {
struct rtentry *tmp_rt = pkt->ro.ro_rt ;
(void)ip_output((struct mbuf *)pkt, (struct mbuf *)pkt->ifp,
&(pkt->ro), pkt->dn_hlen, NULL);
if (tmp_rt)
tmp_rt->rt_refcnt--; /* XXX return a reference count */
}
break ;
case DN_TO_IP_IN :
ip_input((struct mbuf *)pkt) ;
break ;
#ifdef BRIDGE
case DN_TO_BDG_FWD :
bdg_forward((struct mbuf **)&pkt, pkt->ifp);
break ;
#endif
default:
printf("dummynet: bad switch %d!\n", pkt->dn_dir);
m_freem(pkt->dn_m);
FREE(pkt, M_IPFW);
break ;
}
}
}
/*
* this is the periodic task that moves packets between the R-
* and the P- queue
*/
void
dummynet()
{
struct dn_pipe *p ;
int s ;
dn_calls++ ;
for (p = all_pipes ; p ; p = p->next ) {
/*
* Increment the amount of data that can be sent. However,
* don't do that if the channel is idle
* (r.head == NULL && numbytes >= bandwidth).
* This bug fix is from tim shepard (shep@bbn.com)
*/
s = splimp();
if (p->r.head != NULL || p->numbytes < p->bandwidth )
p->numbytes += p->bandwidth ;
dn_move(p, 0); /* is it really 0 (also below) ? */
splx(s);
}
/*
* finally, if some queue has data, restart the timer.
*/
dn_idle = 1;
dn_restart();
}
/*
* dummynet hook for packets.
* input and output use the same code, so i use bit 16 in the pipe
* number to chose the direction: 1 for output packets, 0 for input.
* for input, only m is significant. For output, also the others.
*/
int
dummynet_io(int pipe_nr, int dir,
struct mbuf *m, struct ifnet *ifp, struct route *ro, int hlen,
struct ip_fw_chain *rule)
{
struct dn_pkt *pkt;
struct dn_pipe *pipe;
struct ip *ip=mtod(m, struct ip *);
int s=splimp();
pipe_nr &= 0xffff ;
/*
* locate pipe. First time is expensive, next have direct access.
*/
if ( (pipe = rule->rule->pipe_ptr) == NULL ) {
for (pipe=all_pipes; pipe && pipe->pipe_nr !=pipe_nr; pipe=pipe->next)
;
if (pipe == NULL) {
splx(s);
if (dn_debug)
printf("warning, pkt for no pipe %d\n", pipe_nr);
m_freem(m);
return 0 ;
} else
rule->rule->pipe_ptr = pipe ;
}
/*
* should i drop ?
* This section implements random packet drop.
*/
if ( (pipe->plr && random() < pipe->plr) ||
(pipe->queue_size && pipe->r_len >= pipe->queue_size) ||
(pipe->queue_size_bytes &&
ip->ip_len + pipe->r_len_bytes > pipe->queue_size_bytes) ||
(pkt = (struct dn_pkt *)malloc(sizeof (*pkt),
M_IPFW, M_NOWAIT) ) == NULL ) {
splx(s);
if (dn_debug)
printf("-- dummynet: drop from pipe %d, have %d pks, %d bytes\n",
pipe_nr, pipe->r_len, pipe->r_len_bytes);
pipe->r_drops++ ;
m_freem(m);
return 0 ; /* XXX error */
}
/* build and enqueue packet */
pkt->hdr.mh_type = MT_DUMMYNET ;
(struct ip_fw_chain *)pkt->hdr.mh_data = rule ;
pkt->dn_next = NULL;
pkt->dn_m = m;
pkt->dn_dir = dir ;
pkt->delay = 0;
pkt->ifp = ifp;
if (dir == DN_TO_IP_OUT) {
pkt->ro = *ro; /* XXX copied! */
if (ro->ro_rt)
ro->ro_rt->rt_refcnt++ ; /* XXX */
}
pkt->dn_hlen = hlen;
if (pipe->r.head == NULL)
pipe->r.head = pkt;
else
(struct dn_pkt *)pipe->r.tail->dn_next = pkt;
pipe->r.tail = pkt;
pipe->r_len++;
pipe->r_len_bytes += ip->ip_len ;
/*
* here we could implement RED if we like to
*/
if (pipe->r.head == pkt) { /* process immediately */
dn_move(pipe, 1);
}
splx(s);
if (dn_idle)
dn_restart();
return 0;
}
/*
* dispose all packets queued on a pipe
*/
static void
purge_pipe(struct dn_pipe *pipe)
{
struct dn_pkt *pkt, *n ;
struct rtentry *tmp_rt ;
for (pkt = pipe->r.head ; pkt ; ) {
if (tmp_rt = pkt->ro.ro_rt )
tmp_rt->rt_refcnt--; /* XXX return a reference count */
m_freem(pkt->dn_m);
n = pkt ;
pkt = (struct dn_pkt *)pkt->dn_next ;
free(n, M_IPFW) ;
}
for (pkt = pipe->p.head ; pkt ; ) {
if (tmp_rt = pkt->ro.ro_rt )
tmp_rt->rt_refcnt--; /* XXX return a reference count */
m_freem(pkt->dn_m);
n = pkt ;
pkt = (struct dn_pkt *)pkt->dn_next ;
free(n, M_IPFW) ;
}
}
/*
* delete all pipes returning memory
*/
static void
dummynet_flush()
{
struct dn_pipe *q, *p = all_pipes ;
int s = splnet() ;
all_pipes = NULL ;
splx(s) ;
/*
* purge all queued pkts and delete all pipes
*/
for ( ; p ; ) {
purge_pipe(p);
q = p ;
p = p->next ;
free(q, M_IPFW);
}
}
extern struct ip_fw_chain *ip_fw_default_rule ;
/*
* when a firewall rule is deleted, scan all pipes and remove the flow-id
* from packets matching this rule.
*/
void
dn_rule_delete(void *r)
{
struct dn_pipe *q, *p = all_pipes ;
int matches = 0 ;
for ( p= all_pipes ; p ; p = p->next ) {
struct dn_pkt *x ;
for (x = p->r.head ; x ; x = (struct dn_pkt *)x->dn_next )
if (x->hdr.mh_data == r) {
matches++ ;
x->hdr.mh_data = (void *)ip_fw_default_rule ;
}
for (x = p->p.head ; x ; x = (struct dn_pkt *)x->dn_next )
if (x->hdr.mh_data == r) {
matches++ ;
x->hdr.mh_data = (void *)ip_fw_default_rule ;
}
}
printf("dn_rule_delete, r 0x%x, default 0x%x%s, %d matches\n",
r, ip_fw_default_rule,
r == ip_fw_default_rule ? " AARGH!":"", matches);
}
/*
* handler for the various dummynet socket options
* (get, flush, config, del)
*/
static int
ip_dn_ctl(struct sockopt *sopt)
{
int error = 0 ;
size_t size ;
char *buf, *bp ;
struct dn_pipe *p, *q, tmp_pipe ;
struct dn_pipe *x, *a, *b ;
/* Disallow sets in really-really secure mode. */
if (sopt->sopt_dir == SOPT_SET && securelevel >= 3)
return (EPERM);
switch (sopt->sopt_name) {
default :
panic("ip_dn_ctl -- unknown option");
case IP_DUMMYNET_GET :
for (p = all_pipes, size = 0 ; p ; p = p->next )
size += sizeof( *p ) ;
buf = malloc(size, M_TEMP, M_WAITOK);
if (buf == 0) {
error = ENOBUFS ;
break ;
}
for (p = all_pipes, bp = buf ; p ; p = p->next ) {
struct dn_pipe *q = (struct dn_pipe *)bp ;
bcopy(p, bp, sizeof( *p ) );
/*
* return bw and delay in bits/s and ms, respectively
*/
q->bandwidth *= (8*hz) ;
q->delay = (q->delay * 1000) / hz ;
bp += sizeof( *p ) ;
}
error = sooptcopyout(sopt, buf, size);
FREE(buf, M_TEMP);
break ;
case IP_DUMMYNET_FLUSH :
dummynet_flush() ;
break ;
case IP_DUMMYNET_CONFIGURE :
p = &tmp_pipe ;
error = sooptcopyin(sopt, p, sizeof *p, sizeof *p);
if (error)
break ;
/*
* The config program passes parameters as follows:
* bandwidth = bits/second (0 = no limits);
* must be translated in bytes/tick.
* delay = ms
* must be translated in ticks.
* queue_size = slots (0 = no limit)
* queue_size_bytes = bytes (0 = no limit)
* only one can be set, must be bound-checked
*/
if ( p->bandwidth > 0 ) {
p->bandwidth = p->bandwidth / 8 / hz ;
if (p->bandwidth == 0) /* too little does not make sense! */
p->bandwidth = 10 ;
}
p->delay = ( p->delay * hz ) / 1000 ;
if (p->queue_size == 0 && p->queue_size_bytes == 0)
p->queue_size = 100 ;
if (p->queue_size != 0 ) /* buffers are prevailing */
p->queue_size_bytes = 0 ;
if (p->queue_size > 100)
p->queue_size = 100 ;
if (p->queue_size_bytes > 1024*1024)
p->queue_size_bytes = 1024*1024 ;
#if 0
printf("ip_dn: config pipe %d %d bit/s %d ms %d bufs\n",
p->pipe_nr,
p->bandwidth * 8 * hz ,
p->delay * 1000 / hz , p->queue_size);
#endif
for (a = NULL , b = all_pipes ; b && b->pipe_nr < p->pipe_nr ;
a = b , b = b->next) ;
if (b && b->pipe_nr == p->pipe_nr) {
/* XXX should spl and flush old pipe... */
b->bandwidth = p->bandwidth ;
b->delay = p->delay ;
b->ticks_from_last_insert = p->delay ;
b->queue_size = p->queue_size ;
b->queue_size_bytes = p->queue_size_bytes ;
b->plr = p->plr ;
} else {
int s ;
x = malloc(sizeof(struct dn_pipe), M_IPFW, M_DONTWAIT) ;
if (x == NULL) {
printf("ip_dummynet.c: sorry no memory\n");
error = ENOSPC ;
break ;
}
bzero(x, sizeof(*x) );
x->bandwidth = p->bandwidth ;
x->delay = p->delay ;
x->ticks_from_last_insert = p->delay ;
x->pipe_nr = p->pipe_nr ;
x->queue_size = p->queue_size ;
x->queue_size_bytes = p->queue_size_bytes ;
x->plr = p->plr ;
s = splnet() ;
x->next = b ;
if (a == NULL)
all_pipes = x ;
else
a->next = x ;
splx(s);
}
break ;
case IP_DUMMYNET_DEL :
p = &tmp_pipe ;
error = sooptcopyin(sopt, p, sizeof *p, sizeof *p);
if (error)
break ;
for (a = NULL , b = all_pipes ; b && b->pipe_nr < p->pipe_nr ;
a = b , b = b->next) ;
if (b && b->pipe_nr == p->pipe_nr) { /* found pipe */
int s = splnet() ;
struct ip_fw_chain *chain = ip_fw_chain.lh_first;
if (a == NULL)
all_pipes = b->next ;
else
a->next = b->next ;
/*
* remove references to this pipe from the ip_fw rules.
*/
for (; chain; chain = chain->chain.le_next) {
register struct ip_fw *const f = chain->rule;
if (f->pipe_ptr == b)
f->pipe_ptr = NULL ;
}
splx(s);
purge_pipe(b); /* remove pkts from here */
free(b, M_IPFW);
}
break ;
}
return error ;
}
void
ip_dn_init(void)
{
printf("DUMMYNET initialized (980901) -- size dn_pkt %d\n",
sizeof(struct dn_pkt));
all_pipes = NULL ;
ip_dn_ctl_ptr = ip_dn_ctl;
}
#ifdef DUMMYNET_MODULE
#include <sys/exec.h>
#include <sys/sysent.h>
#include <sys/lkm.h>
MOD_MISC(dummynet);
static ip_dn_ctl_t *old_dn_ctl_ptr ;
static int
dummynet_load(struct lkm_table *lkmtp, int cmd)
{
int s=splnet();
old_dn_ctl_ptr = ip_dn_ctl_ptr;
ip_dn_init();
splx(s);
return 0;
}
static int
dummynet_unload(struct lkm_table *lkmtp, int cmd)
{
int s=splnet();
ip_dn_ctl_ptr = old_dn_ctl_ptr;
splx(s);
dummynet_flush();
printf("DUMMYNET unloaded\n");
return 0;
}
int
dummynet_mod(struct lkm_table *lkmtp, int cmd, int ver)
{
DISPATCH(lkmtp, cmd, ver, dummynet_load, dummynet_unload, lkm_nullcmd);
}
#endif
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