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HardenedBSD/sys/netgraph/ng_lmi.c

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/*
* ng_lmi.c
*
* Copyright (c) 1996-1999 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Author: Julian Elischer <julian@whistle.com>
*
* $FreeBSD$
* $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
*/
/*
* This node performs the frame relay LMI protocol. It knows how
* to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
* of the protocol.
*
* A specific protocol can be forced by connecting the corresponding
* hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
*
* Alternately, this node can do auto-detection of the LMI protocol
* by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_lmi.h>
/*
* Human readable names for LMI
*/
#define NAME_ANNEXA NG_LMI_HOOK_ANNEXA
#define NAME_ANNEXD NG_LMI_HOOK_ANNEXD
#define NAME_GROUP4 NG_LMI_HOOK_GROUPOF4
#define NAME_NONE "None"
#define MAX_DLCIS 128
#define MAXDLCI 1023
/*
* DLCI states
*/
#define DLCI_NULL 0
#define DLCI_UP 1
#define DLCI_DOWN 2
/*
* Any received LMI frame should be at least this long
*/
#define LMI_MIN_LENGTH 8 /* XXX verify */
/*
* Netgraph node methods and type descriptor
*/
static ng_constructor_t nglmi_constructor;
static ng_rcvmsg_t nglmi_rcvmsg;
static ng_shutdown_t nglmi_rmnode;
static ng_newhook_t nglmi_newhook;
static ng_rcvdata_t nglmi_rcvdata;
static ng_disconnect_t nglmi_disconnect;
static int nglmi_checkdata(hook_p hook, struct mbuf *m, meta_p meta);
static struct ng_type typestruct = {
NG_VERSION,
NG_LMI_NODE_TYPE,
NULL,
nglmi_constructor,
nglmi_rcvmsg,
nglmi_rmnode,
nglmi_newhook,
NULL,
NULL,
nglmi_rcvdata,
nglmi_rcvdata,
nglmi_disconnect
};
NETGRAPH_INIT(lmi, &typestruct);
/*
* Info and status per node
*/
struct nglmi_softc {
node_p node; /* netgraph node */
int flags; /* state */
int poll_count; /* the count of times for autolmi */
int poll_state; /* state of auto detect machine */
u_char remote_seq; /* sequence number the remote sent */
u_char local_seq; /* last sequence number we sent */
u_char protoID; /* 9 for group of 4, 8 otherwise */
u_long seq_retries; /* sent this how many time so far */
struct callout_handle handle; /* see timeout(9) */
int liv_per_full;
int liv_rate;
int livs;
int need_full;
hook_p lmi_channel; /* whatever we ended up using */
hook_p lmi_annexA;
hook_p lmi_annexD;
hook_p lmi_group4;
hook_p lmi_channel0; /* auto-detect on DLCI 0 */
hook_p lmi_channel1023;/* auto-detect on DLCI 1023 */
char *protoname; /* cache protocol name */
u_char dlci_state[MAXDLCI + 1];
int invalidx; /* next dlci's to invalidate */
};
typedef struct nglmi_softc *sc_p;
/*
* Other internal functions
*/
static void LMI_ticker(void *arg);
static void nglmi_startup_fixed(sc_p sc, hook_p hook);
static void nglmi_startup_auto(sc_p sc);
static void nglmi_startup(sc_p sc);
static void nglmi_inquire(sc_p sc, int full);
static void ngauto_state_machine(sc_p sc);
/*
* Values for 'flags' field
* NB: the SCF_CONNECTED flag is set if and only if the timer is running.
*/
#define SCF_CONNECTED 0x01 /* connected to something */
#define SCF_AUTO 0x02 /* we are auto-detecting */
#define SCF_FIXED 0x04 /* we are fixed from the start */
#define SCF_LMITYPE 0x18 /* mask for determining Annex mode */
#define SCF_NOLMI 0x00 /* no LMI type selected yet */
#define SCF_ANNEX_A 0x08 /* running annex A mode */
#define SCF_ANNEX_D 0x10 /* running annex D mode */
#define SCF_GROUP4 0x18 /* running group of 4 */
#define SETLMITYPE(sc, annex) \
do { \
(sc)->flags &= ~SCF_LMITYPE; \
(sc)->flags |= (annex); \
} while (0)
#define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
#define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
#define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
#define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
#define LMIPOLLSIZE 3
#define LMI_PATIENCE 8 /* declare all DLCI DOWN after N LMI failures */
/*
* Node constructor
*/
static int
nglmi_constructor(node_p *nodep)
{
sc_p sc;
int error = 0;
MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK);
if (sc == NULL)
return (ENOMEM);
bzero(sc, sizeof(*sc));
callout_handle_init(&sc->handle);
if ((error = ng_make_node_common(&typestruct, nodep))) {
FREE(sc, M_NETGRAPH);
return (error);
}
(*nodep)->private = sc;
sc->protoname = NAME_NONE;
sc->node = *nodep;
sc->liv_per_full = NG_LMI_SEQ_PER_FULL; /* make this dynamic */
sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
return (0);
}
/*
* The LMI channel has a private pointer which is the same as the
* node private pointer. The debug channel has a NULL private pointer.
*/
static int
nglmi_newhook(node_p node, hook_p hook, const char *name)
{
sc_p sc = node->private;
if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
hook->private = NULL;
return (0);
}
if (sc->flags & SCF_CONNECTED) {
/* already connected, return an error */
return (EINVAL);
}
if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
sc->lmi_annexA = hook;
hook->private = node->private;
sc->protoID = 8;
SETLMITYPE(sc, SCF_ANNEX_A);
sc->protoname = NAME_ANNEXA;
nglmi_startup_fixed(sc, hook);
} else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
sc->lmi_annexD = hook;
hook->private = node->private;
sc->protoID = 8;
SETLMITYPE(sc, SCF_ANNEX_D);
sc->protoname = NAME_ANNEXD;
nglmi_startup_fixed(sc, hook);
} else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
sc->lmi_group4 = hook;
hook->private = node->private;
sc->protoID = 9;
SETLMITYPE(sc, SCF_GROUP4);
sc->protoname = NAME_GROUP4;
nglmi_startup_fixed(sc, hook);
} else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
/* Note this, and if B is already installed, we're complete */
sc->lmi_channel0 = hook;
sc->protoname = NAME_NONE;
hook->private = node->private;
if (sc->lmi_channel1023)
nglmi_startup_auto(sc);
} else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
/* Note this, and if A is already installed, we're complete */
sc->lmi_channel1023 = hook;
sc->protoname = NAME_NONE;
hook->private = node->private;
if (sc->lmi_channel0)
nglmi_startup_auto(sc);
} else
return (EINVAL); /* unknown hook */
return (0);
}
/*
* We have just attached to a live (we hope) node.
* Fire out a LMI inquiry, and then start up the timers.
*/
static void
LMI_ticker(void *arg)
{
sc_p sc = arg;
int s = splnet();
if (sc->flags & SCF_AUTO) {
ngauto_state_machine(sc);
sc->handle = timeout(LMI_ticker, sc, NG_LMI_POLL_RATE * hz);
} else {
if (sc->livs++ >= sc->liv_per_full) {
nglmi_inquire(sc, 1);
/* sc->livs = 0; *//* do this when we get the answer! */
} else {
nglmi_inquire(sc, 0);
}
sc->handle = timeout(LMI_ticker, sc, sc->liv_rate * hz);
}
splx(s);
}
static void
nglmi_startup_fixed(sc_p sc, hook_p hook)
{
sc->flags |= (SCF_FIXED | SCF_CONNECTED);
sc->lmi_channel = hook;
nglmi_startup(sc);
}
static void
nglmi_startup_auto(sc_p sc)
{
sc->flags |= (SCF_AUTO | SCF_CONNECTED);
sc->poll_state = 0; /* reset state machine */
sc->poll_count = 0;
nglmi_startup(sc);
}
static void
nglmi_startup(sc_p sc)
{
sc->remote_seq = 0;
sc->local_seq = 1;
sc->seq_retries = 0;
sc->livs = sc->liv_per_full - 1;
/* start off the ticker in 1 sec */
sc->handle = timeout(LMI_ticker, sc, hz);
}
#define META_PAD 16
static void
nglmi_inquire(sc_p sc, int full)
{
struct mbuf *m;
char *cptr, *start;
int error;
meta_p meta = NULL;
if (sc->lmi_channel == NULL)
return;
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
return;
}
m->m_pkthdr.rcvif = NULL;
/* Allocate a meta struct (and leave some slop for options to be
* added by other modules). */
/* MALLOC(meta, meta_p, sizeof( struct ng_meta) + META_PAD,
* M_NETGRAPH, M_NOWAIT); */
MALLOC(meta, meta_p, sizeof(*meta) + META_PAD, M_NETGRAPH, M_NOWAIT);
if (meta != NULL) { /* if it failed, well, it was optional anyhow */
meta->used_len = (u_short) sizeof(struct ng_meta);
meta->allocated_len
= (u_short) sizeof(struct ng_meta) + META_PAD;
meta->flags = 0;
meta->priority = NG_LMI_LMI_PRIORITY;
meta->discardability = -1;
}
m->m_data += 4; /* leave some room for a header */
cptr = start = mtod(m, char *);
/* add in the header for an LMI inquiry. */
*cptr++ = 0x03; /* UI frame */
if (GROUP4(sc))
*cptr++ = 0x09; /* proto discriminator */
else
*cptr++ = 0x08; /* proto discriminator */
*cptr++ = 0x00; /* call reference */
*cptr++ = 0x75; /* inquiry */
/* If we are Annex-D, there is this extra thing.. */
if (ANNEXD(sc))
*cptr++ = 0x95; /* ??? */
/* Add a request type */
if (ANNEXA(sc))
*cptr++ = 0x51; /* report type */
else
*cptr++ = 0x01; /* report type */
*cptr++ = 0x01; /* size = 1 */
if (full)
*cptr++ = 0x00; /* full */
else
*cptr++ = 0x01; /* partial */
/* Add a link verification IE */
if (ANNEXA(sc))
*cptr++ = 0x53; /* verification IE */
else
*cptr++ = 0x03; /* verification IE */
*cptr++ = 0x02; /* 2 extra bytes */
*cptr++ = sc->local_seq;
*cptr++ = sc->remote_seq;
sc->seq_retries++;
/* Send it */
m->m_len = m->m_pkthdr.len = cptr - start;
NG_SEND_DATA(error, sc->lmi_channel, m, meta);
/* If we've been sending requests for long enough, and there has
* been no response, then mark as DOWN, any DLCIs that are UP. */
if (sc->seq_retries == LMI_PATIENCE) {
int count;
for (count = 0; count < MAXDLCI; count++)
if (sc->dlci_state[count] == DLCI_UP)
sc->dlci_state[count] = DLCI_DOWN;
}
}
/*
* State machine for LMI auto-detect. The transitions are ordered
* to try the more likely possibilities first.
*/
static void
ngauto_state_machine(sc_p sc)
{
if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
/* time to change states in the auto probe machine */
/* capture wild values of poll_count while we are at it */
sc->poll_count = LMIPOLLSIZE;
sc->poll_state++;
}
switch (sc->poll_state) {
case 7:
log(LOG_WARNING, "nglmi: no response from exchange\n");
default: /* capture bad states */
sc->poll_state = 1;
case 1:
sc->lmi_channel = sc->lmi_channel0;
SETLMITYPE(sc, SCF_ANNEX_D);
break;
case 2:
sc->lmi_channel = sc->lmi_channel1023;
SETLMITYPE(sc, SCF_ANNEX_D);
break;
case 3:
sc->lmi_channel = sc->lmi_channel0;
SETLMITYPE(sc, SCF_ANNEX_A);
break;
case 4:
sc->lmi_channel = sc->lmi_channel1023;
SETLMITYPE(sc, SCF_GROUP4);
break;
case 5:
sc->lmi_channel = sc->lmi_channel1023;
SETLMITYPE(sc, SCF_ANNEX_A);
break;
case 6:
sc->lmi_channel = sc->lmi_channel0;
SETLMITYPE(sc, SCF_GROUP4);
break;
}
/* send an inquirey encoded appropriatly */
nglmi_inquire(sc, 0);
sc->poll_count--;
}
/*
* Receive a netgraph control message.
*/
static int
nglmi_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
struct ng_mesg **resp)
{
int error = 0;
sc_p sc = node->private;
switch (msg->header.typecookie) {
case NGM_GENERIC_COOKIE:
switch (msg->header.cmd) {
case NGM_TEXT_STATUS:
{
char *arg;
int pos, count;
NG_MKRESPONSE(*resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
if (*resp == NULL) {
error = ENOMEM;
break;
}
arg = (*resp)->data;
pos = sprintf(arg, "protocol %s ", sc->protoname);
if (sc->flags & SCF_FIXED)
pos += sprintf(arg + pos, "fixed\n");
else if (sc->flags & SCF_AUTO)
pos += sprintf(arg + pos, "auto-detecting\n");
else
pos += sprintf(arg + pos, "auto on dlci %d\n",
(sc->lmi_channel == sc->lmi_channel0) ?
0 : 1023);
pos += sprintf(arg + pos,
"keepalive period: %d seconds\n", sc->liv_rate);
pos += sprintf(arg + pos,
"unacknowledged keepalives: %ld\n",
sc->seq_retries);
for (count = 0;
((count <= MAXDLCI)
&& (pos < (NG_TEXTRESPONSE - 20)));
count++) {
if (sc->dlci_state[count]) {
pos += sprintf(arg + pos,
"dlci %d %s\n", count,
(sc->dlci_state[count]
== DLCI_UP) ? "up" : "down");
}
}
(*resp)->header.arglen = pos + 1;
break;
}
default:
error = EINVAL;
break;
}
break;
case NGM_LMI_COOKIE:
switch (msg->header.cmd) {
case NGM_LMI_GET_STATUS:
{
struct nglmistat *stat;
int k;
NG_MKRESPONSE(*resp, msg, sizeof(*stat), M_NOWAIT);
if (!*resp) {
error = ENOMEM;
break;
}
stat = (struct nglmistat *) (*resp)->data;
strncpy(stat->proto,
sc->protoname, sizeof(stat->proto) - 1);
strncpy(stat->hook,
sc->protoname, sizeof(stat->hook) - 1);
stat->autod = !!(sc->flags & SCF_AUTO);
stat->fixed = !!(sc->flags & SCF_FIXED);
for (k = 0; k <= MAXDLCI; k++) {
switch (sc->dlci_state[k]) {
case DLCI_UP:
stat->up[k / 8] |= (1 << (k % 8));
/* fall through */
case DLCI_DOWN:
stat->seen[k / 8] |= (1 << (k % 8));
break;
}
}
break;
}
default:
error = EINVAL;
break;
}
break;
default:
error = EINVAL;
break;
}
FREE(msg, M_NETGRAPH);
return (error);
}
#define STEPBY(stepsize) \
do { \
packetlen -= (stepsize); \
data += (stepsize); \
} while (0)
/*
* receive data, and use it to update our status.
* Anything coming in on the debug port is discarded.
*/
static int
nglmi_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
{
sc_p sc = hook->node->private;
u_char *data;
unsigned short dlci;
u_short packetlen;
int resptype_seen = 0;
int seq_seen = 0;
if (hook->private == NULL) {
goto drop;
}
packetlen = m->m_hdr.mh_len;
/* XXX what if it's more than 1 mbuf? */
if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
goto drop;
}
if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
log(LOG_WARNING,
"nglmi: m_pullup failed for %d bytes\n", packetlen);
NG_FREE_META(meta);
return (0);
}
if (nglmi_checkdata(hook, m, meta) == 0)
return (0);
/* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
data = mtod(m, u_char *);
STEPBY(4);
/* Now check if there is a 'locking shift'. This is only seen in
* Annex D frames. don't bother checking, we already did that. Don't
* increment immediatly as it might not be there. */
if (ANNEXD(sc))
STEPBY(1);
/* If we get this far we should consider that it is a legitimate
* frame and we know what it is. */
if (sc->flags & SCF_AUTO) {
/* note the hook that this valid channel came from and drop
* out of auto probe mode. */
if (ANNEXA(sc))
sc->protoname = NAME_ANNEXA;
else if (ANNEXD(sc))
sc->protoname = NAME_ANNEXD;
else if (GROUP4(sc))
sc->protoname = NAME_GROUP4;
else {
log(LOG_ERR, "nglmi: No known type\n");
goto drop;
}
sc->lmi_channel = hook;
sc->flags &= ~SCF_AUTO;
log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
}
/* While there is more data in the status packet, keep processing
* status items. First make sure there is enough data for the
* segment descriptor's length field. */
while (packetlen >= 2) {
u_int segtype = data[0];
u_int segsize = data[1];
/* Now that we know how long it claims to be, make sure
* there is enough data for the next seg. */
if (packetlen < segsize + 2)
break;
switch (segtype) {
case 0x01:
case 0x51:
if (resptype_seen) {
log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
goto nextIE;
}
resptype_seen++;
/* The remote end tells us what kind of response
* this is. Only expect a type 0 or 1. if we are a
* full status, invalidate a few DLCIs just to see
* that they are still ok. */
if (segsize != 1)
goto nextIE;
switch (data[2]) {
case 1:
/* partial status, do no extra processing */
break;
case 0:
{
int count = 0;
int idx = sc->invalidx;
for (count = 0; count < 10; count++) {
if (idx > MAXDLCI)
idx = 0;
if (sc->dlci_state[idx] == DLCI_UP)
sc->dlci_state[idx] = DLCI_DOWN;
idx++;
}
sc->invalidx = idx;
/* we got and we wanted one. relax
* now.. but don't reset to 0 if it
* was unrequested. */
if (sc->livs > sc->liv_per_full)
sc->livs = 0;
break;
}
}
break;
case 0x03:
case 0x53:
/* The remote tells us what it thinks the sequence
* numbers are. If it's not size 2, it must be a
* duplicate to have gotten this far, skip it. */
if (seq_seen != 0) /* already seen seq numbers */
goto nextIE;
if (segsize != 2)
goto nextIE;
sc->remote_seq = data[2];
if (sc->local_seq == data[3]) {
sc->local_seq++;
sc->seq_retries = 0;
/* Note that all 3 Frame protocols seem to
* not like 0 as a sequence number. */
if (sc->local_seq == 0)
sc->local_seq = 1;
}
break;
case 0x07:
case 0x57:
/* The remote tells us about a DLCI that it knows
* about. There may be many of these in a single
* status response */
switch (segsize) {
case 6:/* only on 'group of 4' */
dlci = ((u_short) data[2] & 0xff) << 8;
dlci |= (data[3] & 0xff);
if ((dlci < 1024) && (dlci > 0)) {
/* XXX */
}
break;
case 3:
dlci = ((u_short) data[2] & 0x3f) << 4;
dlci |= ((data[3] & 0x78) >> 3);
if ((dlci < 1024) && (dlci > 0)) {
/* set up the bottom half of the
* support for that dlci if it's not
* already been done */
/* store this information somewhere */
}
break;
default:
goto nextIE;
}
if (sc->dlci_state[dlci] != DLCI_UP) {
/* bring new DLCI to life */
/* may do more here some day */
if (sc->dlci_state[dlci] != DLCI_DOWN)
log(LOG_INFO,
"nglmi: DLCI %d became active\n",
dlci);
sc->dlci_state[dlci] = DLCI_UP;
}
break;
}
nextIE:
STEPBY(segsize + 2);
}
NG_FREE_DATA(m, meta);
return (0);
drop:
NG_FREE_DATA(m, meta);
return (EINVAL);
}
/*
* Check that a packet is entirely kosha.
* return 1 of ok, and 0 if not.
* All data is discarded if a 0 is returned.
*/
static int
nglmi_checkdata(hook_p hook, struct mbuf *m, meta_p meta)
{
sc_p sc = hook->node->private;
u_char *data;
u_short packetlen;
unsigned short dlci;
u_char type;
u_char nextbyte;
int seq_seen = 0;
int resptype_seen = 0; /* 0 , 1 (partial) or 2 (full) */
int highest_dlci = 0;
packetlen = m->m_hdr.mh_len;
data = mtod(m, u_char *);
if (*data != 0x03) {
log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
goto reject;
}
STEPBY(1);
/* look at the protocol ID */
nextbyte = *data;
if (sc->flags & SCF_AUTO) {
SETLMITYPE(sc, SCF_NOLMI); /* start with a clean slate */
switch (nextbyte) {
case 0x8:
sc->protoID = 8;
break;
case 0x9:
SETLMITYPE(sc, SCF_GROUP4);
sc->protoID = 9;
break;
default:
log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
(int) nextbyte);
goto reject;
}
} else {
if (nextbyte != sc->protoID) {
log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
(int) nextbyte);
goto reject;
}
}
STEPBY(1);
/* check call reference (always null in non ISDN frame relay) */
if (*data != 0x00) {
log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
data[-1]);
goto reject;
}
STEPBY(1);
/* check message type */
switch ((type = *data)) {
case 0x75: /* Status enquiry */
log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
data[-1]);
goto reject;
case 0x7D: /* Status message */
break;
default:
log(LOG_WARNING,
"nglmi: unexpected msg type(0x%x) \n", (int) type);
goto reject;
}
STEPBY(1);
/* Now check if there is a 'locking shift'. This is only seen in
* Annex D frames. Don't increment immediately as it might not be
* there. */
nextbyte = *data;
if (sc->flags & SCF_AUTO) {
if (!(GROUP4(sc))) {
if (nextbyte == 0x95) {
SETLMITYPE(sc, SCF_ANNEX_D);
STEPBY(1);
} else
SETLMITYPE(sc, SCF_ANNEX_A);
} else if (nextbyte == 0x95) {
log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
goto reject;
}
} else {
if (ANNEXD(sc)) {
if (*data == 0x95)
STEPBY(1);
else {
log(LOG_WARNING,
"nglmi: locking shift missing\n");
goto reject;
}
} else if (*data == 0x95) {
log(LOG_WARNING, "nglmi: locking shift seen\n");
goto reject;
}
}
/* While there is more data in the status packet, keep processing
* status items. First make sure there is enough data for the
* segment descriptor's length field. */
while (packetlen >= 2) {
u_int segtype = data[0];
u_int segsize = data[1];
/* Now that we know how long it claims to be, make sure
* there is enough data for the next seg. */
if (packetlen < (segsize + 2)) {
log(LOG_WARNING, "nglmi: IE longer than packet\n");
break;
}
switch (segtype) {
case 0x01:
case 0x51:
/* According to MCI's HP analyser, we should just
* ignore if there is mor ethan one of these (?). */
if (resptype_seen) {
log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
goto nextIE;
}
if (segsize != 1) {
log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
goto reject;
}
/* The remote end tells us what kind of response
* this is. Only expect a type 0 or 1. if it was a
* full (type 0) check we just asked for a type
* full. */
switch (data[2]) {
case 1:/* partial */
if (sc->livs > sc->liv_per_full) {
log(LOG_WARNING,
"nglmi: LIV when FULL expected\n");
goto reject; /* need full */
}
resptype_seen = 1;
break;
case 0:/* full */
/* Full response is always acceptable */
resptype_seen = 2;
break;
default:
log(LOG_WARNING,
"nglmi: Unknown report type %d\n", data[2]);
goto reject;
}
break;
case 0x03:
case 0x53:
/* The remote tells us what it thinks the sequence
* numbers are. I would have thought that there
* needs to be one and only one of these, but MCI
* want us to just ignore extras. (?) */
if (resptype_seen == 0) {
log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
goto reject;
}
if (seq_seen != 0) /* already seen seq numbers */
goto nextIE;
if (segsize != 2) {
log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
goto reject;
}
if (sc->local_seq != data[3]) {
log(LOG_WARNING, "nglmi: unexpected SEQ\n");
goto reject;
}
seq_seen = 1;
break;
case 0x07:
case 0x57:
/* The remote tells us about a DLCI that it knows
* about. There may be many of these in a single
* status response */
if (seq_seen != 1) { /* already seen seq numbers? */
log(LOG_WARNING,
"nglmi: No sequence before DLCI\n");
goto reject;
}
if (resptype_seen != 2) { /* must be full */
log(LOG_WARNING,
"nglmi: No resp type before DLCI\n");
goto reject;
}
if (GROUP4(sc)) {
if (segsize != 6) {
log(LOG_WARNING,
"nglmi: wrong IE segsize\n");
goto reject;
}
dlci = ((u_short) data[2] & 0xff) << 8;
dlci |= (data[3] & 0xff);
} else {
if (segsize != 3) {
log(LOG_WARNING,
"nglmi: DLCI headersize of %d"
" not supported\n", segsize - 1);
goto reject;
}
dlci = ((u_short) data[2] & 0x3f) << 4;
dlci |= ((data[3] & 0x78) >> 3);
}
/* async can only have one of these */
#if 0 /* async not yet accepted */
if (async && highest_dlci) {
log(LOG_WARNING,
"nglmi: Async with > 1 DLCI\n");
goto reject;
}
#endif
/* Annex D says these will always be Ascending, but
* the HP test for G4 says we should accept
* duplicates, so for now allow that. ( <= vs. < ) */
#if 0
/* MCI tests want us to accept out of order for AnxD */
if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
/* duplicate or mis-ordered dlci */
/* (spec says they will increase in number) */
log(LOG_WARNING, "nglmi: DLCI out of order\n");
goto reject;
}
#endif
if (dlci > 1023) {
log(LOG_WARNING, "nglmi: DLCI out of range\n");
goto reject;
}
highest_dlci = dlci;
break;
default:
log(LOG_WARNING,
"nglmi: unknown LMI segment type %d\n", segtype);
}
nextIE:
STEPBY(segsize + 2);
}
if (packetlen != 0) { /* partial junk at end? */
log(LOG_WARNING,
"nglmi: %d bytes extra at end of packet\n", packetlen);
goto print;
}
if (resptype_seen == 0) {
log(LOG_WARNING, "nglmi: No response type seen\n");
goto reject; /* had no response type */
}
if (seq_seen == 0) {
log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
goto reject; /* had no sequence numbers */
}
return (1);
print:
{
int i, j, k, pos;
char buf[100];
int loc;
u_char *bp = mtod(m, u_char *);
k = i = 0;
loc = (m->m_hdr.mh_len - packetlen);
log(LOG_WARNING, "nglmi: error at location %d\n", loc);
while (k < m->m_hdr.mh_len) {
pos = 0;
j = 0;
while ((j++ < 16) && k < m->m_hdr.mh_len) {
pos += sprintf(buf + pos, "%c%02x",
((loc == k) ? '>' : ' '),
bp[k]);
k++;
}
if (i == 0)
log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
else
log(LOG_WARNING, "%04d :%s\n", k, buf);
i++;
}
}
return (1);
reject:
{
int i, j, k, pos;
char buf[100];
int loc;
u_char *bp = mtod(m, u_char *);
k = i = 0;
loc = (m->m_hdr.mh_len - packetlen);
log(LOG_WARNING, "nglmi: error at location %d\n", loc);
while (k < m->m_hdr.mh_len) {
pos = 0;
j = 0;
while ((j++ < 16) && k < m->m_hdr.mh_len) {
pos += sprintf(buf + pos, "%c%02x",
((loc == k) ? '>' : ' '),
bp[k]);
k++;
}
if (i == 0)
log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
else
log(LOG_WARNING, "%04d :%s\n", k, buf);
i++;
}
}
NG_FREE_DATA(m, meta);
return (0);
}
/*
* Do local shutdown processing..
* Cut any remaining links and free our local resources.
*/
static int
nglmi_rmnode(node_p node)
{
const sc_p sc = node->private;
node->flags |= NG_INVALID;
ng_cutlinks(node);
ng_unname(node);
node->private = NULL;
ng_unref(sc->node);
FREE(sc, M_NETGRAPH);
return (0);
}
/*
* Hook disconnection
* For this type, removal of any link except "debug" destroys the node.
*/
static int
nglmi_disconnect(hook_p hook)
{
const sc_p sc = hook->node->private;
/* OK to remove debug hook(s) */
if (hook->private == NULL)
return (0);
/* Stop timer if it's currently active */
if (sc->flags & SCF_CONNECTED)
untimeout(LMI_ticker, sc, sc->handle);
/* Self-destruct */
ng_rmnode(hook->node);
return (0);
}
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