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Handle hardware-imposed MTU/MRU limitations. PPPoE will no longer

Browse Source 
allow MRU/MTU negotiations to exceed 1492.

Add an optional ``max'' specifier to ``set m[rt]u'', ie.

	set mtu max 1480

Bump the ppp version number.

Sponsored by:	Monzoon Networks AG and FreeBSD Services Limited
This commit is contained in:
Brian Somers 2001-06-18 14:59:36 +00:00
parent 29d19e86ae
commit c8b9fb53a1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=78410
21 changed files with 246 additions and 80 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
usr.sbin/ppp/atm.c
View File

@ -122,6 +122,7 @@ atm_device2iov(struct device *d, struct iovec *iov, int *niov,
static const struct device baseatmdevice = {
ATM_DEVICE,
"atm",
0,
{ CD_NOTREQUIRED, 0 },
NULL,
NULL,

21
usr.sbin/ppp/bundle.c
View File

@ -802,7 +802,6 @@ bundle_Create(const char *prefix, int type, int unit)
log_Printf(LogPHASE, "Using interface: %s\n", ifname);
bundle.bandwidth = 0;
bundle.mtu = 1500;
bundle.routing_seq = 0;
bundle.phase = PHASE_DEAD;
bundle.CleaningUp = 0;
@ -821,7 +820,6 @@ bundle_Create(const char *prefix, int type, int unit)
bundle.cfg.opt = OPT_SROUTES | OPT_IDCHECK | OPT_LOOPBACK | OPT_TCPMSSFIXUP |
OPT_THROUGHPUT | OPT_UTMP;
*bundle.cfg.label = '\0';
bundle.cfg.mtu = DEF_MTU;
bundle.cfg.ifqueue = DEF_IFQUEUE;
bundle.cfg.choked.timeout = CHOKED_TIMEOUT;
bundle.phys_type.all = type;
@ -1096,11 +1094,6 @@ bundle_ShowStatus(struct cmdargs const *arg)
prompt_Printf(arg->prompt, "\n");
} else
prompt_Printf(arg->prompt, "disabled\n");
prompt_Printf(arg->prompt, " MTU: ");
if (arg->bundle->cfg.mtu)
prompt_Printf(arg->prompt, "%d\n", arg->bundle->cfg.mtu);
else
prompt_Printf(arg->prompt, "unspecified\n");
prompt_Printf(arg->prompt, " sendpipe: ");
if (arg->bundle->ncp.ipcp.cfg.sendpipe > 0)
@ -1826,7 +1819,7 @@ bundle_CalculateBandwidth(struct bundle *bundle)
int sp;
bundle->bandwidth = 0;
bundle->mtu = 0;
bundle->iface->mtu = 0;
for (dl = bundle->links; dl; dl = dl->next)
if (dl->state == DATALINK_OPEN) {
if ((sp = dl->mp.bandwidth) == 0 &&
@ -1836,7 +1829,7 @@ bundle_CalculateBandwidth(struct bundle *bundle)
else
bundle->bandwidth += sp;
if (!bundle->ncp.mp.active) {
bundle->mtu = dl->physical->link.lcp.his_mru;
bundle->iface->mtu = dl->physical->link.lcp.his_mru;
break;
}
}
@ -1845,16 +1838,16 @@ bundle_CalculateBandwidth(struct bundle *bundle)
bundle->bandwidth = 115200; /* Shrug */
if (bundle->ncp.mp.active)
bundle->mtu = bundle->ncp.mp.peer_mrru;
else if (!bundle->mtu)
bundle->mtu = 1500;
bundle->iface->mtu = bundle->ncp.mp.peer_mrru;
else if (!bundle->iface->mtu)
bundle->iface->mtu = DEF_MRU;
#ifndef NORADIUS
if (bundle->radius.valid && bundle->radius.mtu &&
bundle->radius.mtu < bundle->mtu) {
bundle->radius.mtu < bundle->iface->mtu) {
log_Printf(LogLCP, "Reducing MTU to radius value %lu\n",
bundle->radius.mtu);
bundle->mtu = bundle->radius.mtu;
bundle->iface->mtu = bundle->radius.mtu;
}
#endif

2
usr.sbin/ppp/bundle.h
View File

@ -73,7 +73,6 @@ struct bundle {
} dev;
u_long bandwidth; /* struct tuninfo speed */
int mtu; /* struct tuninfo MTU */
struct iface *iface; /* Interface information */
int routing_seq; /* The current routing sequence number */
@ -103,7 +102,6 @@ struct bundle {
} auth;
unsigned opt; /* Uses OPT_ bits from above */
char label[50]; /* last thing `load'ed */
u_short mtu; /* Required interface MTU */
u_short ifqueue; /* Interface queue size */
struct {

77
usr.sbin/ppp/command.c
View File

@ -159,7 +159,7 @@
#define NEG_MPPE 54
#define NEG_CHAP81 55
const char Version[] = "2.3.1";
const char Version[] = "2.3.2";
static int ShowCommand(struct cmdargs const *);
static int TerminalCommand(struct cmdargs const *);
@ -1489,6 +1489,7 @@ SetVariable(struct cmdargs const *arg)
{
long long_val, param = (long)arg->cmd->args;
int mode, dummyint, f, first;
u_short *change;
const char *argp;
struct datalink *cx = arg->cx; /* LOCAL_CX uses this */
const char *err = NULL;
@ -1678,9 +1679,36 @@ SetVariable(struct cmdargs const *arg)
break;
case VAR_MRU:
long_val = atol(argp);
switch(arg->argc - arg->argn) {
case 1:
if (argp[strspn(argp, "0123456789")] != '\0')
return -1;
case 0:
long_val = atol(argp);
change = &l->lcp.cfg.mru;
if (long_val > l->lcp.cfg.max_mru) {
log_Printf(LogWARN, "MRU %ld: too large - max set to %d\n", long_val,
l->lcp.cfg.max_mru);
return 1;
}
break;
case 2:
if (strcasecmp(argp, "max") && strcasecmp(argp, "maximum"))
return -1;
long_val = atol(arg->argv[arg->argn + 1]);
change = &l->lcp.cfg.max_mru;
if (long_val > MAX_MRU) {
log_Printf(LogWARN, "MRU %ld: too large - maximum is %d\n", long_val,
MAX_MRU);
return 1;
}
break;
default:
return -1;
}
if (long_val == 0)
l->lcp.cfg.mru = DEF_MRU;
*change = DEF_MRU;
else if (long_val < MIN_MRU) {
log_Printf(LogWARN, "MRU %ld: too small - min %d\n", long_val, MIN_MRU);
return 1;
@ -1688,11 +1716,40 @@ SetVariable(struct cmdargs const *arg)
log_Printf(LogWARN, "MRU %ld: too big - max %d\n", long_val, MAX_MRU);
return 1;
} else
l->lcp.cfg.mru = long_val;
*change = long_val;
if (l->lcp.cfg.mru > *change)
l->lcp.cfg.mru = *change;
break;
case VAR_MTU:
long_val = atol(argp);
switch(arg->argc - arg->argn) {
case 1:
if (argp[strspn(argp, "0123456789")] != '\0')
return -1;
case 0:
long_val = atol(argp);
change = &l->lcp.cfg.mtu;
if (long_val > l->lcp.cfg.max_mtu) {
log_Printf(LogWARN, "MTU %ld: too large - max set to %d\n", long_val,
l->lcp.cfg.max_mtu);
return 1;
}
break;
case 2:
if (strcasecmp(argp, "max") && strcasecmp(argp, "maximum"))
return -1;
long_val = atol(arg->argv[arg->argn + 1]);
change = &l->lcp.cfg.max_mtu;
if (long_val > MAX_MTU) {
log_Printf(LogWARN, "MTU %ld: too large - maximum is %d\n", long_val,
MAX_MTU);
return 1;
}
break;
default:
return -1;
}
if (long_val && long_val < MIN_MTU) {
log_Printf(LogWARN, "MTU %ld: too small - min %d\n", long_val, MIN_MTU);
return 1;
@ -1700,7 +1757,9 @@ SetVariable(struct cmdargs const *arg)
log_Printf(LogWARN, "MTU %ld: too big - max %d\n", long_val, MAX_MTU);
return 1;
} else
arg->bundle->cfg.mtu = long_val;
*change = long_val;
if (l->lcp.cfg.mtu > *change)
l->lcp.cfg.mtu = *change;
break;
case VAR_OPENMODE:
@ -2064,9 +2123,9 @@ static struct cmdtab const SetCommands[] = {
{"mrru", NULL, SetVariable, LOCAL_AUTH, "MRRU value",
"set mrru value", (const void *)VAR_MRRU},
{"mru", NULL, SetVariable, LOCAL_AUTH | LOCAL_CX_OPT,
"MRU value", "set mru value", (const void *)VAR_MRU},
{"mtu", NULL, SetVariable, LOCAL_AUTH,
"interface MTU value", "set mtu value", (const void *)VAR_MTU},
"MRU value", "set mru [max[imum]] [value]", (const void *)VAR_MRU},
{"mtu", NULL, SetVariable, LOCAL_AUTH | LOCAL_CX,
"interface MTU value", "set mtu [max[imum]] [value]", (const void *)VAR_MTU},
{"nbns", NULL, SetVariable, LOCAL_AUTH, "NetBIOS Name Server",
"set nbns pri-addr [sec-addr]", (const void *)VAR_NBNS},
{"openmode", NULL, SetVariable, LOCAL_AUTH | LOCAL_CX, "open mode",

11
usr.sbin/ppp/ether.c
View File

@ -285,6 +285,7 @@ ether_AwaitCarrier(struct physical *p)
static const struct device baseetherdevice = {
ETHER_DEVICE,
"ether",
1492,
{ CD_REQUIRED, DEF_ETHERCDDELAY },
ether_AwaitCarrier,
ether_RemoveFromSet,
@ -675,16 +676,6 @@ ether_Create(struct physical *p)
if (dev) {
physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
/* Moan about (and fix) invalid LCP configurations */
if (p->link.lcp.cfg.mru > 1492) {
log_Printf(LogWARN, "%s: Reducing MRU to 1492\n", p->link.name);
p->link.lcp.cfg.mru = 1492;
}
if (p->dl->bundle->cfg.mtu > 1492) {
log_Printf(LogWARN, "%s: Reducing MTU to 1492\n", p->link.name);
p->dl->bundle->cfg.mtu = 1492;
}
if (path != NULL) {
/* Mark the interface as UP if it's not already */

1
usr.sbin/ppp/exec.c
View File

@ -68,6 +68,7 @@
static struct device execdevice = {
EXEC_DEVICE,
"exec",
0,
{ CD_NOTREQUIRED, 0 },
NULL,
NULL,

1
usr.sbin/ppp/i4b.c
View File

@ -293,6 +293,7 @@ i4b_device2iov(struct device *d, struct iovec *iov, int *niov,
static struct device basei4bdevice = {
I4B_DEVICE,
"i4b",
0,
{ CD_REQUIRED, DEF_I4BCDDELAY },
i4b_AwaitCarrier,
NULL,

5
usr.sbin/ppp/iface.c
View File

@ -163,8 +163,9 @@ iface_Create(const char *name)
return NULL;
}
iface->name = strdup(name);
iface->flags = ifm->ifm_flags;
iface->index = ifm->ifm_index;
iface->flags = ifm->ifm_flags;
iface->mtu = 0;
iface->in_addrs = 0;
iface->in_addr = NULL;
}
@ -540,7 +541,7 @@ iface_Show(struct cmdargs const *arg)
if_flags[f].value);
flags &= ~if_flags[f].flag;
}
prompt_Printf(arg->prompt, "> mtu %d has %d address%s:\n", arg->bundle->mtu,
prompt_Printf(arg->prompt, "> mtu %d has %d address%s:\n", iface->mtu,
iface->in_addrs, iface->in_addrs == 1 ? "" : "es");
for (f = 0; f < iface->in_addrs; f++) {

1
usr.sbin/ppp/iface.h
View File

@ -39,6 +39,7 @@ struct iface {
char *name; /* Interface name (malloc'd) */
int index; /* Interface index */
int flags; /* Interface flags (IFF_*) */
int mtu; /* struct tuninfo MTU */
int in_addrs; /* How many in_addr's */
struct iface_addr *in_addr; /* Array of addresses (malloc'd) */

79
usr.sbin/ppp/lcp.c
View File

@ -177,7 +177,13 @@ lcp_ReportStatus(struct cmdargs const *arg)
(u_long)lcp->want_magic, lcp->want_mrru,
lcp->want_shortseq ? "on" : "off", lcp->my_reject);
prompt_Printf(arg->prompt, "\n Defaults: MRU = %d, ", lcp->cfg.mru);
prompt_Printf(arg->prompt, "\n Defaults: MRU = %d (max %d), ",
lcp->cfg.mru, lcp->cfg.max_mru);
if (lcp->cfg.mtu)
prompt_Printf(arg->prompt, "MTU = %d (max %d), ",
lcp->cfg.mtu, lcp->cfg.max_mtu);
else
prompt_Printf(arg->prompt, "MTU = any (max %d), ", lcp->cfg.max_mtu);
prompt_Printf(arg->prompt, "ACCMAP = %08lx\n", (u_long)lcp->cfg.accmap);
prompt_Printf(arg->prompt, " LQR period = %us, ",
lcp->cfg.lqrperiod);
@ -241,6 +247,9 @@ lcp_Init(struct lcp *lcp, struct bundle *bundle, struct link *l,
bundle, l, parent, &lcp_Callbacks, lcp_TimerNames);
lcp->cfg.mru = DEF_MRU;
lcp->cfg.max_mru = MAX_MRU;
lcp->cfg.mtu = 0;
lcp->cfg.max_mtu = MAX_MTU;
lcp->cfg.accmap = 0;
lcp->cfg.openmode = 1;
lcp->cfg.lqrperiod = DEF_LQRPERIOD;
@ -266,11 +275,12 @@ lcp_Init(struct lcp *lcp, struct bundle *bundle, struct link *l,
void
lcp_Setup(struct lcp *lcp, int openmode)
{
struct physical *p = link2physical(lcp->fsm.link);
int phmtu = p ? physical_DeviceMTU(p) : 0;
lcp->fsm.open_mode = openmode;
lcp->his_mru = lcp->fsm.bundle->cfg.mtu;
if (!lcp->his_mru || lcp->his_mru > DEF_MRU)
lcp->his_mru = DEF_MRU;
lcp->his_mru = DEF_MRU;
lcp->his_mrru = 0;
lcp->his_magic = 0;
lcp->his_lqrperiod = 0;
@ -281,13 +291,13 @@ lcp_Setup(struct lcp *lcp, int openmode)
lcp->his_shortseq = 0;
lcp->want_mru = lcp->cfg.mru;
if (phmtu && lcp->want_mru > phmtu)
lcp->want_mru = phmtu;
lcp->want_mrru = lcp->fsm.bundle->ncp.mp.cfg.mrru;
lcp->want_shortseq = IsEnabled(lcp->fsm.bundle->ncp.mp.cfg.shortseq) ? 1 : 0;
lcp->want_acfcomp = IsEnabled(lcp->cfg.acfcomp) ? 1 : 0;
if (lcp->fsm.parent) {
struct physical *p = link2physical(lcp->fsm.link);
lcp->his_accmap = 0xffffffff;
lcp->want_accmap = lcp->cfg.accmap;
lcp->his_protocomp = 0;
@ -592,15 +602,15 @@ LcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
{
/* Deal with incoming PROTO_LCP */
struct lcp *lcp = fsm2lcp(fp);
int type, length, sz, pos, op, callback_req;
int type, length, sz, pos, op, callback_req, mru_req;
u_int32_t magic, accmap;
u_short mtu, mru, proto;
u_short mru, phmtu, proto;
struct lqrreq *req;
char request[20], desc[22];
struct mp *mp;
struct physical *p = link2physical(fp->link);
sz = op = callback_req = 0;
sz = op = callback_req = mru_req = 0;
while (plen >= sizeof(struct fsmconfig)) {
type = *cp;
@ -626,7 +636,13 @@ LcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
/* Ignore his previous reject so that we REQ next time */
lcp->his_reject &= ~(1 << type);
if (mru < MIN_MRU) {
if (mru > MAX_MRU) {
/* Push him down to MAX_MRU */
lcp->his_mrru = MAX_MRU;
memcpy(dec->nakend, cp, 2);
ua_htons(&lcp->his_mrru, dec->nakend + 2);
dec->nakend += 4;
} else if (mru < MIN_MRU) {
/* Push him up to MIN_MRU */
lcp->his_mrru = MIN_MRU;
memcpy(dec->nakend, cp, 2);
@ -664,28 +680,41 @@ LcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
break;
case TY_MRU:
mru_req = 1;
ua_ntohs(cp + 2, &mru);
log_Printf(LogLCP, "%s %d\n", request, mru);
switch (mode_type) {
case MODE_REQ:
mtu = lcp->fsm.bundle->cfg.mtu;
if (mru < MIN_MRU || (!lcp->want_mrru && mru < mtu)) {
phmtu = p ? physical_DeviceMTU(p) : 0;
if (phmtu && mru > phmtu) {
lcp->his_mru = lcp->cfg.mtu ? lcp->cfg.mtu : phmtu;
memcpy(dec->nakend, cp, 2);
ua_htons(&lcp->his_mru, dec->nakend + 2);
dec->nakend += 4;
} if (mru > lcp->cfg.max_mtu) {
lcp->his_mru = lcp->cfg.mtu ? lcp->cfg.mtu : lcp->cfg.max_mtu;
memcpy(dec->nakend, cp, 2);
ua_htons(&lcp->his_mru, dec->nakend + 2);
dec->nakend += 4;
} else if (mru < MIN_MRU || mru < lcp->cfg.mtu) {
/* Push him up to MTU or MIN_MRU */
lcp->his_mru = mru < mtu ? mtu : MIN_MRU;
lcp->his_mru = mru < lcp->cfg.mtu ? lcp->cfg.mtu : MIN_MRU;
memcpy(dec->nakend, cp, 2);
ua_htons(&lcp->his_mru, dec->nakend + 2);
dec->nakend += 4;
} else {
lcp->his_mru = mtu ? mtu : mru;
lcp->his_mru = lcp->cfg.mtu ? lcp->cfg.mtu : mru;
memcpy(dec->ackend, cp, 4);
dec->ackend += 4;
}
break;
case MODE_NAK:
if (mru > MAX_MRU)
lcp->want_mru = MAX_MRU;
else if (mru < MIN_MRU)
if (mru > lcp->cfg.max_mru) {
lcp->want_mru = lcp->cfg.max_mru;
if (p && lcp->want_mru > physical_DeviceMTU(p))
lcp->want_mru = physical_DeviceMTU(p);
} else if (mru < MIN_MRU)
lcp->want_mru = MIN_MRU;
else
lcp->want_mru = mru;
@ -1217,6 +1246,22 @@ LcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
dec->nakend[-1] = 2; /* XXX: Silly ! */
}
}
if (mode_type == MODE_REQ && !mru_req) {
mru = DEF_MRU;
phmtu = p ? physical_DeviceMTU(p) : 0;
if (phmtu && mru > phmtu)
mru = phmtu;
if (mru > lcp->cfg.max_mtu)
mru = lcp->cfg.max_mtu;
if (mru < DEF_MRU) {
/* Don't let the peer use the default MRU */
lcp->his_mru = lcp->cfg.mtu && lcp->cfg.mtu < mru ? lcp->cfg.mtu : mru;
*dec->nakend++ = TY_MRU;
*dec->nakend++ = 4;
ua_htons(&lcp->his_mru, dec->nakend);
dec->nakend += 2;
}
}
if (dec->rejend != dec->rej) {
/* rejects are preferred */
dec->ackend = dec->ack;

3
usr.sbin/ppp/lcp.h
View File

@ -82,6 +82,9 @@ struct lcp {
struct {
u_short mru; /* Preferred MRU value */
u_short max_mru; /* Preferred MRU value */
u_short mtu; /* Preferred MTU */
u_short max_mtu; /* Preferred MTU */
u_int32_t accmap; /* Initial ACCMAP value */
int openmode; /* when to start CFG REQs */
u_int32_t lqrperiod; /* LQR frequency (seconds) */

6
usr.sbin/ppp/physical.c
View File

@ -758,6 +758,12 @@ physical_IsSync(struct physical *p)
return p->cfg.speed == 0;
}
u_short
physical_DeviceMTU(struct physical *p)
{
return p->handler ? p->handler->mtu : 0;
}
const char *physical_GetDevice(struct physical *p)
{
return p->name.full;

2
usr.sbin/ppp/physical.h
View File

@ -56,6 +56,7 @@ struct cd {
struct device {
int type;
const char *name;
u_short mtu;
struct cd cd;
int (*awaitcarrier)(struct physical *);
@ -143,6 +144,7 @@ extern const char *physical_LockedDevice(struct physical *);
extern void physical_ChangedPid(struct physical *, pid_t);
extern int physical_IsSync(struct physical *);
extern u_short physical_DeviceMTU(struct physical *);
extern const char *physical_GetDevice(struct physical *);
extern void physical_SetDeviceList(struct physical *, int, const char *const *);
extern void physical_SetDevice(struct physical *, const char *);

46
usr.sbin/ppp/ppp.8
View File

@ -4917,32 +4917,60 @@ Setting this option enables Multi-link PPP negotiations, also known as
Multi-link Protocol or MP.
There is no default MRRU (Maximum Reconstructed Receive Unit) value.
If no argument is given, multi-link mode is disabled.
.It set mru Op Ar value
.It set mru Oo max Ns Oo imum Oc Oc Op Ar value
The default MRU (Maximum Receive Unit) is 1500.
If it is increased, the other side *may* increase its MTU.
There is no point in decreasing the MRU to below the default as the
In theory there is no point in decreasing the MRU to below the default as the
.Em PPP
protocol *must* be able to accept packets of at least 1500 octets.
protocol says implementations *must* be able to accept packets of at
least 1500 octets.
.Pp
If the
.Dq maximum
keyword is used,
.Nm
will refuse to negotiate a higher value.
The maximum MRU can be set to 2048 at most.
Setting a maximum of less than 1500 violates the
.Em PPP
rfc, but may sometimes be necessary.
For example,
.Em PPPoE
imposes a maximum of 1492 due to hardware limitations.
.Pp
If no argument is given, 1500 is assumed.
.It set mtu Op Ar value
A value must be given when
.Dq maximum
is specified.
.It set mtu Oo max Ns Oo imum Oc Oc Op Ar value
The default MTU is 1500.
At negotiation time,
.Nm
will accept whatever MRU or MRRU that the peer wants (assuming it's
not less than 296 bytes).
will accept whatever MRU the peer requests (assuming it's
not less than 296 bytes or greater than the assigned maximum).
If the MTU is set,
.Nm
will not accept MRU/MRRU values less than
will not accept MRU values less than
.Ar value .
When negotiations are complete, the MTU is assigned to the interface, even
if the peer requested a higher value MRU/MRRU.
When negotiations are complete, the MTU is used when writing to the
interface, even if the peer requested a higher value MRU.
This can be useful for
limiting your packet size (giving better bandwidth sharing at the expense
of more header data).
.Pp
If the
.Dq maximum
keyword is used,
.Nm
will refuse to negotiate a higher value.
The maximum MTU can be set to 2048 at most.
.Pp
If no
.Ar value
is given, 1500, or whatever the peer asks for is used.
A value must be given when
.Dq maximum
is specified.
.It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
This option allows the setting of the Microsoft NetBIOS name server
values to be returned at the peers request.

46
usr.sbin/ppp/ppp.8.m4
View File

@ -4917,32 +4917,60 @@ Setting this option enables Multi-link PPP negotiations, also known as
Multi-link Protocol or MP.
There is no default MRRU (Maximum Reconstructed Receive Unit) value.
If no argument is given, multi-link mode is disabled.
.It set mru Op Ar value
.It set mru Oo max Ns Oo imum Oc Oc Op Ar value
The default MRU (Maximum Receive Unit) is 1500.
If it is increased, the other side *may* increase its MTU.
There is no point in decreasing the MRU to below the default as the
In theory there is no point in decreasing the MRU to below the default as the
.Em PPP
protocol *must* be able to accept packets of at least 1500 octets.
protocol says implementations *must* be able to accept packets of at
least 1500 octets.
.Pp
If the
.Dq maximum
keyword is used,
.Nm
will refuse to negotiate a higher value.
The maximum MRU can be set to 2048 at most.
Setting a maximum of less than 1500 violates the
.Em PPP
rfc, but may sometimes be necessary.
For example,
.Em PPPoE
imposes a maximum of 1492 due to hardware limitations.
.Pp
If no argument is given, 1500 is assumed.
.It set mtu Op Ar value
A value must be given when
.Dq maximum
is specified.
.It set mtu Oo max Ns Oo imum Oc Oc Op Ar value
The default MTU is 1500.
At negotiation time,
.Nm
will accept whatever MRU or MRRU that the peer wants (assuming it's
not less than 296 bytes).
will accept whatever MRU the peer requests (assuming it's
not less than 296 bytes or greater than the assigned maximum).
If the MTU is set,
.Nm
will not accept MRU/MRRU values less than
will not accept MRU values less than
.Ar value .
When negotiations are complete, the MTU is assigned to the interface, even
if the peer requested a higher value MRU/MRRU.
When negotiations are complete, the MTU is used when writing to the
interface, even if the peer requested a higher value MRU.
This can be useful for
limiting your packet size (giving better bandwidth sharing at the expense
of more header data).
.Pp
If the
.Dq maximum
keyword is used,
.Nm
will refuse to negotiate a higher value.
The maximum MTU can be set to 2048 at most.
.Pp
If no
.Ar value
is given, 1500, or whatever the peer asks for is used.
A value must be given when
.Dq maximum
is specified.
.It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
This option allows the setting of the Microsoft NetBIOS name server
values to be returned at the peers request.

7
usr.sbin/ppp/route.c
View File

@ -577,9 +577,8 @@ route_UpdateMTU(struct bundle *bundle)
log_Printf(LogTCPIP, "route_UpdateMTU: Netif: %d (%s), dst %s, mtu %d\n",
rtm->rtm_index, Index2Nam(rtm->rtm_index),
inet_ntoa(((struct sockaddr_in *)sa[RTAX_DST])->sin_addr),
bundle->mtu);
rt_Update(bundle, in[RTAX_DST]->sin_addr,
in[RTAX_GATEWAY]->sin_addr);
bundle->iface->mtu);
rt_Update(bundle, in[RTAX_DST]->sin_addr, in[RTAX_GATEWAY]->sin_addr);
}
}
@ -890,7 +889,7 @@ rt_Update(struct bundle *bundle, struct in_addr dst, struct in_addr gw)
rtmes.m_rtm.rtm_inits |= RTV_RPIPE;
}
rtmes.m_rtm.rtm_rmx.rmx_mtu = bundle->mtu;
rtmes.m_rtm.rtm_rmx.rmx_mtu = bundle->iface->mtu;
rtmes.m_rtm.rtm_inits |= RTV_MTU;
memset(&rtdata, '\0', sizeof rtdata);

1
usr.sbin/ppp/tcp.c
View File

@ -100,6 +100,7 @@ tcp_OpenConnection(const char *name, char *host, char *port)
static struct device tcpdevice = {
TCP_DEVICE,
"tcp",
0,
{ CD_NOTREQUIRED, 0 },
NULL,
NULL,

5
usr.sbin/ppp/tcpmss.c
View File

@ -28,6 +28,8 @@
#include <sys/param.h>
#include <sys/socket.h>
#include <net/route.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
@ -54,6 +56,7 @@
#include "filter.h"
#include "descriptor.h"
#include "mp.h"
#include "iface.h"
#ifndef NORADIUS
#include "radius.h"
#endif
@ -93,7 +96,7 @@ tcpmss_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp,
ntohs(pip->ip_len) == plen && hlen <= plen &&
plen - hlen >= sizeof(struct tcphdr))
MSSFixup((struct tcphdr *)(MBUF_CTOP(bp) + hlen), plen - hlen,
MAXMSS(bundle->mtu));
MAXMSS(bundle->iface->mtu));
return bp;
}

1
usr.sbin/ppp/tty.c
View File

@ -333,6 +333,7 @@ tty_device2iov(struct device *d, struct iovec *iov, int *niov,
static struct device basettydevice = {
TTY_DEVICE,
"tty",
0,
{ CD_VARIABLE, DEF_TTYCDDELAY },
tty_AwaitCarrier,
NULL,

9
usr.sbin/ppp/tun.c
View File

@ -27,10 +27,12 @@
*/
#include <sys/param.h>
#ifndef __FreeBSD__
#include <sys/socket.h> /* For IFF_ defines */
#ifndef __FreeBSD__
#include <net/if.h> /* For IFF_ defines */
#endif
#include <net/route.h>
#include <netinet/in.h>
#include <net/if_types.h>
#include <net/if_tun.h>
@ -68,6 +70,7 @@
#include "ccp.h"
#include "link.h"
#include "mp.h"
#include "iface.h"
#ifndef NORADIUS
#include "radius.h"
#endif
@ -89,7 +92,7 @@ tun_configure(struct bundle *bundle)
}
sprintf(ifr.ifr_name, "tun%d", bundle->unit);
ifr.ifr_mtu = bundle->mtu;
ifr.ifr_mtu = bundle->iface->mtu;
if (ioctl(s, SIOCSIFMTU, &ifr) < 0)
log_Printf(LogERROR, "tun_configure: ioctl(SIOCSIFMTU): %s\n",
strerror(errno));
@ -100,7 +103,7 @@ tun_configure(struct bundle *bundle)
memset(&info, '\0', sizeof info);
info.type = IFT_PPP;
info.mtu = bundle->mtu;
info.mtu = bundle->iface->mtu;
info.baudrate = bundle->bandwidth;
#ifdef __OpenBSD__

1
usr.sbin/ppp/udp.c
View File

@ -154,6 +154,7 @@ udp_device2iov(struct device *d, struct iovec *iov, int *niov,
static const struct device baseudpdevice = {
UDP_DEVICE,
"udp",
0,
{ CD_NOTREQUIRED, 0 },
NULL,
NULL,