dummynet: add simple gilbert-elliott channel model

Have a simple Gilbert-Elliott channel model in
dummynet to mimick correlated loss behavior of
realistic environments. This allows simpler testing
of burst-loss environments.

Reviewed By:           tuexen, kp, pauamma_gundo.com, #manpages
Sponsored by:          NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D42980
This commit is contained in:
Richard Scheffenegger 2023-12-17 13:19:52 +01:00
parent 4fb5eda649
commit 31cf66d755
7 changed files with 235 additions and 37 deletions

View File

@ -471,7 +471,7 @@ print_flowset_parms(struct dn_fs *fs, char *prefix)
{
int l;
char qs[30];
char plr[30];
char plr[40];
char red[200]; /* Display RED parameters */
l = fs->qsize;
@ -482,9 +482,17 @@ print_flowset_parms(struct dn_fs *fs, char *prefix)
sprintf(qs, "%d B", l);
} else
sprintf(qs, "%3d sl.", l);
if (fs->plr)
sprintf(plr, "plr %f", 1.0 * fs->plr / (double)(0x7fffffff));
else
if (fs->plr[0] || fs->plr[1]) {
if (fs->plr[1] == 0)
sprintf(plr, "plr %f",
1.0 * fs->plr[0] / (double)(0x7fffffff));
else
sprintf(plr, "plr %f,%f,%f,%f",
1.0 * fs->plr[0] / (double)(0x7fffffff),
1.0 * fs->plr[1] / (double)(0x7fffffff),
1.0 * fs->plr[2] / (double)(0x7fffffff),
1.0 * fs->plr[3] / (double)(0x7fffffff));
} else
plr[0] = '\0';
if (fs->flags & DN_IS_RED) { /* RED parameters */
@ -1408,13 +1416,27 @@ ipfw_config_pipe(int ac, char **av)
case TOK_PLR:
NEED(fs, "plr is only for pipes");
NEED1("plr needs argument 0..1\n");
d = strtod(av[0], NULL);
if (d > 1)
d = 1;
else if (d < 0)
d = 0;
fs->plr = (int)(d*0x7fffffff);
NEED1("plr needs one or four arguments 0..1\n");
if ((end = strsep(&av[0], ","))) {
d = strtod(end, NULL);
d = (d < 0) ? 0 : (d <= 1) ? d : 1;
fs->plr[0] = (int)(d*0x7fffffff);
}
if ((end = strsep(&av[0], ","))) {
d = strtod(end, NULL);
d = (d < 0) ? 0 : (d <= 1) ? d : 1;
fs->plr[1] = (int)(d*0x7fffffff);
}
if ((end = strsep(&av[0], ","))) {
d = strtod(end, NULL);
d = (d < 0) ? 0 : (d <= 1) ? d : 1;
fs->plr[2] = (int)(d*0x7fffffff);
}
if ((end = strsep(&av[0], ","))) {
d = strtod(end, NULL);
d = (d < 0) ? 0 : (d <= 1) ? d : 1;
fs->plr[3] = (int)(d*0x7fffffff);
}
ac--; av++;
break;

View File

@ -1,5 +1,5 @@
.\"
.Dd September 28, 2023
.Dd December 17, 2023
.Dt IPFW 8
.Os
.Sh NAME
@ -3039,12 +3039,47 @@ needed for some experimental setups where you want to simulate
loss or congestion at a remote router.
.Pp
.It Cm plr Ar packet-loss-rate
.It Cm plr Ar K,p,H,r
Packet loss rate.
Argument
.Ar packet-loss-rate
is a floating-point number between 0 and 1, with 0 meaning no
loss, 1 meaning 100% loss.
The loss rate is internally represented on 31 bits.
.Pp
When invoked with four arguments, the simple Gilbert-Elliott
channel model with two states (Good and Bad) is used.
.Bd -literal -offset indent
r
.----------------.
v |
.------------. .------------.
| G | | B |
| drop (K) | | drop (H) |
'------------' '------------'
| ^
'----------------'
p
.Ed
This has the associated probabilities
.Po Ar K
and
.Ar H Pc
for the loss probability. This is different from the literature,
where this model is described with probabilities of successful
transmission k and h. However, converting from literature is
easy:
.Pp
K = 1 - k ; H = 1 - h
.Pp
This is to retain consistency within the interface and allow the
quick re-use of loss probability when giving only a single argument.
In addition the state change probabilities
.Po Ar p
and
.Ar r Pc
are given.
All of the above probabilities are internally represented on 31 bits.
.Pp
.It Cm queue Brq Ar slots | size Ns Cm Kbytes
Queue size, in

View File

@ -145,7 +145,7 @@ struct dn_fs {
uint32_t fs_nr; /* the flowset number */
uint32_t flags; /* userland flags */
int qsize; /* queue size in slots or bytes */
int32_t plr; /* PLR, pkt loss rate (2^31-1 means 100%) */
int32_t pl_state; /* packet loss state */
uint32_t buckets; /* buckets used for the queue hash table */
struct ipfw_flow_id flow_mask;
@ -168,6 +168,7 @@ struct dn_fs {
int min_th ; /* minimum threshold for queue (scaled) */
int max_p ; /* maximum value for p_b (scaled) */
int32_t plr[4]; /* PLR, pkt loss rate (2^31-1 means 100%) */
};
/*

View File

@ -77,35 +77,35 @@ struct dn_heap7 {
/* Common to 7.2 and 8 */
struct dn_flow_set {
SLIST_ENTRY(dn_flow_set) next; /* linked list in a hash slot */
SLIST_ENTRY(dn_flow_set) next; /* linked list in a hash slot */
u_short fs_nr ; /* flow_set number */
u_short fs_nr ; /* flow_set number */
u_short flags_fs;
#define DNOLD_HAVE_FLOW_MASK 0x0001
#define DNOLD_IS_RED 0x0002
#define DNOLD_IS_RED 0x0002
#define DNOLD_IS_GENTLE_RED 0x0004
#define DNOLD_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */
#define DNOLD_NOERROR 0x0010 /* do not report ENOBUFS on drops */
#define DNOLD_HAS_PROFILE 0x0020 /* the pipe has a delay profile. */
#define DNOLD_IS_PIPE 0x4000
#define DNOLD_IS_QUEUE 0x8000
#define DNOLD_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */
#define DNOLD_NOERROR 0x0010 /* do not report ENOBUFS on drops */
#define DNOLD_HAS_PROFILE 0x0020 /* the pipe has a delay profile. */
#define DNOLD_IS_PIPE 0x4000
#define DNOLD_IS_QUEUE 0x8000
struct dn_pipe7 *pipe ; /* pointer to parent pipe */
u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */
struct dn_pipe7 *pipe ; /* pointer to parent pipe */
u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */
int weight ; /* WFQ queue weight */
int qsize ; /* queue size in slots or bytes */
int plr ; /* pkt loss rate (2^31-1 means 100%) */
int weight ; /* WFQ queue weight */
int qsize ; /* queue size in slots or bytes */
int plr[4] ; /* pkt loss rate (2^31-1 means 100%) */
struct ipfw_flow_id flow_mask ;
/* hash table of queues onto this flow_set */
int rq_size ; /* number of slots */
int rq_elements ; /* active elements */
struct dn_flow_queue7 **rq; /* array of rq_size entries */
int rq_size ; /* number of slots */
int rq_elements ; /* active elements */
struct dn_flow_queue7 **rq ; /* array of rq_size entries */
u_int32_t last_expired ; /* do not expire too frequently */
int backlogged ; /* #active queues for this flowset */
u_int32_t last_expired ; /* do not expire too frequently */
int backlogged ; /* #active queues for this flowset */
/* RED parameters */
#define SCALE_RED 16
@ -420,7 +420,10 @@ dn_compat_config_queue(struct dn_fs *fs, void* v)
fs->flow_mask = f->flow_mask;
fs->buckets = f->rq_size;
fs->qsize = f->qsize;
fs->plr = f->plr;
fs->plr[0] = f->plr[0];
fs->plr[1] = f->plr[1];
fs->plr[2] = f->plr[2];
fs->plr[3] = f->plr[3];
fs->par[0] = f->weight;
fs->flags = convertflags2new(f->flags_fs);
if (fs->flags & DN_IS_GENTLE_RED || fs->flags & DN_IS_RED) {
@ -645,7 +648,10 @@ dn_c_copy_pipe(struct dn_schk *s, struct copy_args *a, int nq)
fs->parent_nr = l->link_nr - DN_MAX_ID;
fs->qsize = f->fs.qsize;
fs->plr = f->fs.plr;
fs->plr[0] = f->fs.plr[0];
fs->plr[1] = f->fs.plr[1];
fs->plr[2] = f->fs.plr[2];
fs->plr[3] = f->fs.plr[3];
fs->w_q = f->fs.w_q;
fs->max_th = f->max_th;
fs->min_th = f->min_th;
@ -698,7 +704,10 @@ dn_c_copy_fs(struct dn_fsk *f, struct copy_args *a, int nq)
fs->next.sle_next = (struct dn_flow_set *)DN_IS_QUEUE;
fs->fs_nr = f->fs.fs_nr;
fs->qsize = f->fs.qsize;
fs->plr = f->fs.plr;
fs->plr[0] = f->fs.plr[0];
fs->plr[1] = f->fs.plr[1];
fs->plr[2] = f->fs.plr[2];
fs->plr[3] = f->fs.plr[3];
fs->w_q = f->fs.w_q;
fs->max_th = f->max_th;
fs->min_th = f->min_th;

View File

@ -497,8 +497,28 @@ dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop)
ni->tot_pkts++;
if (drop)
goto drop;
if (f->plr && random() < f->plr)
goto drop;
if (f->plr[0] || f->plr[1]) {
if (__predict_true(f->plr[1] == 0)) {
if (random() < f->plr[0])
goto drop;
} else {
switch (f->pl_state) {
case PLR_STATE_B:
if (random() < f->plr[3])
f->pl_state = PLR_STATE_G;
if (random() < f->plr[2])
goto drop;
break;
case PLR_STATE_G: /* FALLTHROUGH */
default:
if (random() < f->plr[1])
f->pl_state = PLR_STATE_B;
if (random() < f->plr[0])
goto drop;
break;
}
}
}
if (m->m_pkthdr.rcvif != NULL)
m_rcvif_serialize(m);
#ifdef NEW_AQM

View File

@ -392,6 +392,15 @@ enum {
PROTO_IFB = 0x0c, /* layer2 + ifbridge */
};
/*
* States for the Packet Loss Rate Gilbert-Elliott
* channel model
*/
enum {
PLR_STATE_G = 0,
PLR_STATE_B,
};
//extern struct dn_parms V_dn_cfg;
VNET_DECLARE(struct dn_parms, dn_cfg);
#define V_dn_cfg VNET(dn_cfg)

View File

@ -517,6 +517,102 @@ nat_cleanup()
firewall_cleanup $1
}
pls_basic_head()
{
atf_set descr 'Basic dummynet packet loss rate test'
atf_set require.user root
}
pls_basic_body()
{
fw=$1
firewall_init $fw
dummynet_init $fw
epair=$(vnet_mkepair)
vnet_mkjail alcatraz ${epair}b
ifconfig ${epair}a 192.0.2.1/24 up
jexec alcatraz ifconfig ${epair}b 192.0.2.2/24 up
firewall_config alcatraz ${fw} \
"ipfw" \
"ipfw add 65432 ip from any to any" \
"pf" \
"pass on ${epair}b"
# Sanity check
atf_check -s exit:0 -o match:'100 packets transmitted, 100 packets received' ping -i .1 -c 100 192.0.2.2
jexec alcatraz dnctl pipe 1 config plr 0.1
firewall_config alcatraz ${fw} \
"ipfw" \
"ipfw add 1000 pipe 1 ip from 192.0.2.1 to 192.0.2.2" \
"pf" \
"pass on ${epair}b dnpipe 1"
# check if the expected number of pings
# are dropped (84 - 96 responses).
# repeat up to 6 times if the initial
# checks fail
atf_check -s exit:0 -o match:'100 packets transmitted, (8[4-9]|9[0-6]) packets received' -r 6:10 ping -i 0.010 -c 100 192.0.2.2
}
pls_basic_cleanup()
{
firewall_cleanup $1
}
pls_gilbert_head()
{
atf_set descr 'dummynet Gilbert-Elliott packet loss model test'
atf_set require.user root
}
pls_gilbert_body()
{
fw=$1
firewall_init $fw
dummynet_init $fw
epair=$(vnet_mkepair)
vnet_mkjail alcatraz ${epair}b
ifconfig ${epair}a 192.0.2.1/24 up
jexec alcatraz ifconfig ${epair}b 192.0.2.2/24 up
firewall_config alcatraz ${fw} \
"ipfw" \
"ipfw add 65432 ip from any to any" \
"pf" \
"pass on ${epair}b"
# Sanity check
atf_check -s exit:0 -o match:'100 packets transmitted, 100 packets received' ping -i .1 -c 100 192.0.2.2
jexec alcatraz dnctl pipe 1 config plr 0.01,0.1,0.8,0.2
firewall_config alcatraz ${fw} \
"ipfw" \
"ipfw add 1000 pipe 1 ip from 192.0.2.1 to 192.0.2.2" \
"pf" \
"pass on ${epair}b dnpipe 1"
# check if the expected number of pings
# are dropped (70 - 85 responses).
# repeat up to 6 times if the initial
# checks fail
atf_check -s exit:0 -o match:'100 packets transmitted, (7[0-9]|8[0-5]) packets received' -r 6:10 ping -i 0.010 -c 100 192.0.2.2
}
pls_gilbert_cleanup()
{
firewall_cleanup $1
}
setup_tests \
interface_removal \
ipfw \
@ -539,4 +635,10 @@ setup_tests \
ipfw \
pf \
nat \
pf \
pls_basic \
ipfw \
pf \
pls_gilbert \
ipfw \
pf