458 lines
10 KiB
C
458 lines
10 KiB
C
/*
|
|
* cbcp - Call Back Configuration Protocol.
|
|
*
|
|
* Copyright (c) 1995 Pedro Roque Marques
|
|
* All rights reserved.
|
|
*
|
|
* 2000-07-25 Callback improvements by richard.kunze@web.de
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that the above copyright notice and this paragraph are
|
|
* duplicated in all such forms and that any documentation,
|
|
* advertising materials, and other materials related to such
|
|
* distribution and use acknowledge that the software was developed
|
|
* by Pedro Roque Marques. The name of the author may not be used to
|
|
* endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*/
|
|
|
|
/*
|
|
Microsoft Call Back Configuration Protocol.
|
|
by Pedro Roque Marques
|
|
|
|
The CBCP is a method by which the Microsoft Windows NT Server may
|
|
implement additional security. It is possible to configure the server
|
|
in such a manner so as to require that the client systems which
|
|
connect with it are required that following a valid authentication to
|
|
leave a method by which the number may be returned call.
|
|
|
|
It is a requirement of servers so configured that the protocol be
|
|
exchanged.
|
|
|
|
So, this set of patches may be applied to the pppd process to enable
|
|
the cbcp client *only* portion of the specification. It is primarily
|
|
meant to permit connection with Windows NT Servers.
|
|
|
|
The ietf-working specification may be obtained from ftp.microsoft.com
|
|
in the developr/rfc directory.
|
|
|
|
*/
|
|
|
|
#define PPP_CBCP 0xc029 /* Callback Control Protocol */
|
|
|
|
char cbcp_rcsid[] = "$Id$";
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/time.h>
|
|
#include <syslog.h>
|
|
|
|
#include "ipppd.h"
|
|
#include "cbcp.h"
|
|
#include "fsm.h"
|
|
#include "lcp.h"
|
|
#include "ipcp.h"
|
|
|
|
|
|
/*
|
|
* Protocol entry points.
|
|
*/
|
|
static void cbcp_init __P((int unit));
|
|
static void cbcp_open __P((int unit));
|
|
static void cbcp_close __P((int unit,char *));
|
|
static void cbcp_lowerup __P((int unit));
|
|
static void cbcp_lowerdown __P((int unit));
|
|
static void cbcp_input __P((int unit, u_char *pkt, int len));
|
|
static void cbcp_protrej __P((int unit));
|
|
static int cbcp_printpkt __P((u_char *pkt, int len,
|
|
void (*printer) __P((void *, char *, ...)),
|
|
void *arg));
|
|
|
|
struct protent cbcp_protent = {
|
|
PPP_CBCP,
|
|
cbcp_init,
|
|
cbcp_input,
|
|
cbcp_protrej,
|
|
cbcp_lowerup,
|
|
cbcp_lowerdown,
|
|
cbcp_open,
|
|
cbcp_close,
|
|
cbcp_printpkt,
|
|
NULL,
|
|
0,
|
|
"CBCP",
|
|
NULL,
|
|
NULL,
|
|
NULL
|
|
};
|
|
|
|
|
|
cbcp_state cbcp[NUM_PPP];
|
|
|
|
/* internal prototypes */
|
|
|
|
void cbcp_recvreq(cbcp_state *us, char *pckt, int len);
|
|
void cbcp_resp(cbcp_state *us);
|
|
void cbcp_up(cbcp_state *us);
|
|
void cbcp_recvack(cbcp_state *us, char *pckt, int len);
|
|
void cbcp_send(cbcp_state *us, u_char code, u_char *buf, int len);
|
|
|
|
/* init state */
|
|
static void cbcp_init(int cbcp_unit)
|
|
{
|
|
cbcp_state *us;
|
|
|
|
us = &cbcp[cbcp_unit];
|
|
memset(us, 0, sizeof(cbcp_state));
|
|
us->us_unit = -1;
|
|
us->us_type |= (1 << CB_CONF_NO);
|
|
us->us_type |= (1 << CB_CONF_USER);
|
|
us->us_type |= (1 << CB_CONF_LIST);
|
|
us->us_type |= (1 << CB_CONF_ADMIN);
|
|
}
|
|
|
|
/* lower layer is up */
|
|
static void cbcp_lowerup(int cbcp_unit)
|
|
{
|
|
#if 0
|
|
cbcp_state *us = &cbcp[cbcp_unit];
|
|
#endif
|
|
syslog(LOG_DEBUG, "cbcp_lowerup");
|
|
}
|
|
|
|
static void cbcp_lowerdown(int cbcp_unit)
|
|
{
|
|
syslog(LOG_DEBUG, "cbcp_lowerdown");
|
|
}
|
|
|
|
static void cbcp_open(int cbcp_unit)
|
|
{
|
|
syslog(LOG_DEBUG, "cbcp_open");
|
|
}
|
|
|
|
static void cbcp_close(int cbcp_unit,char *reason)
|
|
{
|
|
syslog(LOG_DEBUG, "cbcp_close: %s",reason);
|
|
}
|
|
|
|
/* process an incomming packet */
|
|
static void cbcp_input(int cbcp_unit, u_char *inpacket, int pktlen)
|
|
{
|
|
u_char *inp;
|
|
u_char code, id;
|
|
u_short len;
|
|
|
|
cbcp_state *us = &cbcp[cbcp_unit];
|
|
|
|
inp = inpacket;
|
|
|
|
if (pktlen < CBCP_MINLEN) {
|
|
syslog(LOG_ERR, "CBCP packet is too small");
|
|
return;
|
|
}
|
|
|
|
GETCHAR(code, inp);
|
|
GETCHAR(id, inp);
|
|
GETSHORT(len, inp);
|
|
|
|
#if 0
|
|
if (len > pktlen) {
|
|
syslog(LOG_ERR, "CBCP packet: invalid length");
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
len -= CBCP_MINLEN;
|
|
|
|
switch(code) {
|
|
case CBCP_REQ:
|
|
us->us_id = id;
|
|
cbcp_recvreq(us, inp, len);
|
|
break;
|
|
|
|
case CBCP_RESP:
|
|
syslog(LOG_DEBUG, "CBCP_RESP received");
|
|
break;
|
|
|
|
case CBCP_ACK:
|
|
if (id != us->us_id)
|
|
syslog(LOG_DEBUG, "id doesn't match: expected %d recv %d",
|
|
us->us_id, id);
|
|
|
|
cbcp_recvack(us, inp, len);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* protocol was rejected by foe */
|
|
static void cbcp_protrej(int cbcp_unit)
|
|
{
|
|
}
|
|
|
|
char *cbcp_codenames[] = {"Request", "Response", "Ack"};
|
|
|
|
char *cbcp_optionnames[] = { "NoCallback",
|
|
"UserDefined",
|
|
"AdminDefined",
|
|
"List"};
|
|
/* pretty print a packet */
|
|
static int cbcp_printpkt(u_char *p, int plen,
|
|
void (*printer) __P((void *, char *, ...)),
|
|
void *arg)
|
|
{
|
|
int code, opt, id, len, olen, delay;
|
|
u_char *pstart;
|
|
|
|
if (plen < HEADERLEN)
|
|
return 0;
|
|
pstart = p;
|
|
GETCHAR(code, p);
|
|
GETCHAR(id, p);
|
|
GETSHORT(len, p);
|
|
if (len < HEADERLEN || len > plen)
|
|
return 0;
|
|
|
|
if (code >= 1 && code <= sizeof(cbcp_codenames) / sizeof(char *))
|
|
printer(arg, " %s", cbcp_codenames[code-1]);
|
|
else
|
|
printer(arg, " code=0x%x", code);
|
|
|
|
printer(arg, " id=0x%x", id);
|
|
len -= HEADERLEN;
|
|
|
|
switch (code) {
|
|
case CBCP_REQ:
|
|
case CBCP_RESP:
|
|
case CBCP_ACK:
|
|
while(len >= 2) {
|
|
GETCHAR(opt, p);
|
|
GETCHAR(olen, p);
|
|
|
|
if (olen < 2 || olen > len) {
|
|
break;
|
|
}
|
|
|
|
printer(arg, " <");
|
|
len -= olen;
|
|
|
|
if (opt >= 1 && opt <= sizeof(cbcp_optionnames) / sizeof(char *))
|
|
printer(arg, " %s", cbcp_optionnames[opt-1]);
|
|
else
|
|
printer(arg, " option=0x%x", opt);
|
|
|
|
if (olen > 2) {
|
|
GETCHAR(delay, p);
|
|
printer(arg, " delay = %d", delay);
|
|
}
|
|
|
|
if (olen > 3) {
|
|
int addrt;
|
|
char str[256];
|
|
|
|
GETCHAR(addrt, p);
|
|
memcpy(str, p, olen - 4);
|
|
str[olen - 4] = 0;
|
|
printer(arg, " number = %s", str);
|
|
}
|
|
printer(arg, ">");
|
|
break;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
for (; len > 0; --len) {
|
|
GETCHAR(code, p);
|
|
printer(arg, " %.2x", code);
|
|
}
|
|
|
|
return p - pstart;
|
|
}
|
|
|
|
/* received CBCP request */
|
|
|
|
void cbcp_recvreq(cbcp_state *us, char *pckt, int pcktlen)
|
|
{
|
|
u_char type, opt_len, delay, addr_type;
|
|
char address[256];
|
|
int len = pcktlen;
|
|
|
|
address[0] = 0;
|
|
|
|
while (len) {
|
|
syslog(LOG_DEBUG, "length: %d", len);
|
|
|
|
GETCHAR(type, pckt);
|
|
GETCHAR(opt_len, pckt);
|
|
|
|
if (opt_len > 2)
|
|
GETCHAR(delay, pckt);
|
|
|
|
us->us_allowed |= (1 << type);
|
|
|
|
switch(type) {
|
|
case CB_CONF_NO:
|
|
syslog(LOG_DEBUG, "no callback allowed");
|
|
break;
|
|
|
|
case CB_CONF_USER:
|
|
syslog(LOG_DEBUG, "user callback allowed");
|
|
if (opt_len > 4) {
|
|
GETCHAR(addr_type, pckt);
|
|
memcpy(address, pckt, opt_len - 4);
|
|
address[opt_len - 4] = 0;
|
|
if (address[0])
|
|
syslog(LOG_DEBUG, "address: %s", address);
|
|
}
|
|
break;
|
|
|
|
case CB_CONF_ADMIN:
|
|
syslog(LOG_DEBUG, "user admin defined allowed");
|
|
break;
|
|
|
|
case CB_CONF_LIST:
|
|
break;
|
|
}
|
|
len -= opt_len;
|
|
}
|
|
|
|
cbcp_resp(us);
|
|
}
|
|
|
|
void cbcp_resp(cbcp_state *us)
|
|
{
|
|
u_char cb_type;
|
|
u_char buf[256];
|
|
u_char *bufp = buf;
|
|
int len = 0;
|
|
struct callback_opts *cbopt;
|
|
|
|
cbopt = &lcp_wantoptions[ lns[us->us_unit].lcp_unit ].cbopt;
|
|
|
|
/* Always allow "no callback" and admin defined callback */
|
|
us->us_type |= (1 << CB_CONF_NO);
|
|
us->us_type |= (1 << CB_CONF_ADMIN);
|
|
|
|
/* Only go for user defined or choode from a list callback if
|
|
we do have a phone number to be called back at */
|
|
if (cbopt->message && cbopt->mlen) {
|
|
us->us_type |= (1 << CB_CONF_USER);
|
|
us->us_type |= (1 << CB_CONF_LIST);
|
|
}
|
|
cb_type = us->us_allowed & us->us_type;
|
|
syslog(LOG_DEBUG, "cbcp_resp: cb_type=%d", cb_type);
|
|
|
|
if (!cb_type) {
|
|
syslog(LOG_INFO, "Your remote side wanted a callback-type you don't allow -> doing no callback");
|
|
cb_type = 1 << CB_CONF_NO;
|
|
}
|
|
|
|
if (cb_type & ( 1 << CB_CONF_USER ) ) {
|
|
syslog(LOG_DEBUG, "cbcp_resp CONF_USER");
|
|
PUTCHAR(CB_CONF_USER, bufp);
|
|
len = 3 + 1 + cbopt->mlen + 1;
|
|
PUTCHAR(len , bufp);
|
|
PUTCHAR(cbopt->delay, bufp); /* delay */
|
|
PUTCHAR(1, bufp); /* Message type. Always 1
|
|
according to the protocol specs,
|
|
but you never know with MS
|
|
protocols ;-/ */
|
|
BCOPY(cbopt->message, bufp, cbopt->mlen + 1);
|
|
cbcp_send(us, CBCP_RESP, buf, len);
|
|
return;
|
|
}
|
|
|
|
/* XXX: Callback to one number from a server defined list not yet
|
|
implemented */
|
|
|
|
if (cb_type & ( 1 << CB_CONF_ADMIN ) ) {
|
|
PUTCHAR(CB_CONF_ADMIN, bufp);
|
|
len = 3;
|
|
PUTCHAR(len , bufp);
|
|
PUTCHAR(cbopt->delay, bufp);
|
|
cbcp_send(us, CBCP_RESP, buf, len);
|
|
return;
|
|
}
|
|
|
|
if (cb_type & ( 1 << CB_CONF_NO ) ) {
|
|
syslog(LOG_DEBUG, "cbcp_resp CONF_NO");
|
|
PUTCHAR(CB_CONF_NO, bufp);
|
|
len = 2;
|
|
PUTCHAR(len , bufp);
|
|
cbcp_send(us, CBCP_RESP, buf, len);
|
|
#if 0
|
|
/*
|
|
* what should we do here ... check this! */
|
|
*/
|
|
ipcp_open( lns[us->us_unit].ipcp_unit );
|
|
#endif
|
|
return;
|
|
}
|
|
}
|
|
|
|
void cbcp_send(cbcp_state *us, u_char code, u_char *buf, int len)
|
|
{
|
|
u_char *outp;
|
|
int outlen;
|
|
|
|
outp = outpacket_buf;
|
|
|
|
outlen = 4 + len;
|
|
|
|
MAKEHEADER(outp, PPP_CBCP);
|
|
|
|
PUTCHAR(code, outp);
|
|
PUTCHAR(us->us_id, outp);
|
|
PUTSHORT(outlen, outp);
|
|
|
|
if (len)
|
|
BCOPY(buf, outp, len);
|
|
|
|
output_ppp(us->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
|
|
}
|
|
|
|
void cbcp_recvack(cbcp_state *us, char *pckt, int len)
|
|
{
|
|
u_char type, delay, addr_type;
|
|
int opt_len;
|
|
char address[256];
|
|
|
|
if (len) {
|
|
GETCHAR(type, pckt);
|
|
GETCHAR(opt_len, pckt);
|
|
|
|
if (opt_len > 2)
|
|
GETCHAR(delay, pckt);
|
|
|
|
if (opt_len > 4) {
|
|
GETCHAR(addr_type, pckt);
|
|
memcpy(address, pckt, opt_len - 4);
|
|
address[opt_len - 4] = 0;
|
|
if (address[0])
|
|
syslog(LOG_DEBUG, "peer will call: %s", address);
|
|
}
|
|
}
|
|
|
|
cbcp_up(us);
|
|
}
|
|
|
|
/* ok peer will do callback */
|
|
void cbcp_up(cbcp_state *us)
|
|
{
|
|
int linkunit = us->us_unit;
|
|
lcp_close( lns[linkunit].lcp_unit ,"callback initiated sucessfully");
|
|
lns[linkunit].phase = PHASE_TERMINATE;
|
|
}
|
|
|
|
|
|
|