URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [pppd/] [cbcp.c] - Blame information for rev 30

Go to most recent revision | Details | Compare with Previous | View Log


/*
 * cbcp - Call Back Configuration Protocol.
 *
 * Copyright (c) 1995 Pedro Roque Marques
 * All rights reserved.
 *
 * 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.
 */
 
#ifndef lint
/* static char rcsid[] = "$Id: cbcp.c,v 1.2 2001-09-27 12:01:57 chris Exp $"; */
#endif
 
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include <syslog.h>
 
#include "pppd.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_lowerup   __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,
    NULL,
    cbcp_open,
    NULL,
    cbcp_printpkt,
    NULL,
    0,
    "CBCP",
    NULL,
    NULL,
    NULL
};
 
cbcp_state cbcp[NUM_PPP];
 
/* internal prototypes */
 
static void cbcp_recvreq __P((cbcp_state *us, char *pckt, int len));
static void cbcp_resp __P((cbcp_state *us));
static void cbcp_up __P((cbcp_state *us));
static void cbcp_recvack __P((cbcp_state *us, char *pckt, int len));
static void cbcp_send __P((cbcp_state *us, u_char code, u_char *buf, int len));
 
/* init state */
static void
cbcp_init(iface)
    int iface;
{
    cbcp_state *us;
 
    us = &cbcp[iface];
    memset(us, 0, sizeof(cbcp_state));
    us->us_unit = iface;
    us->us_type |= (1 << CB_CONF_NO);
}
 
/* lower layer is up */
static void
cbcp_lowerup(iface)
    int iface;
{
    cbcp_state *us = &cbcp[iface];
 
 
    syslog(LOG_DEBUG, "cbcp_lowerup");
    syslog(LOG_DEBUG, "want: %d", us->us_type);
 
    if (us->us_type == CB_CONF_USER)
        syslog(LOG_DEBUG, "phone no: %s", us->us_number);
}
 
static void
cbcp_open(unit)
    int unit;
{
    syslog(LOG_DEBUG, "cbcp_open");
}
 
/* process an incomming packet */
static void
cbcp_input(unit, inpacket, pktlen)
    int unit;
    u_char *inpacket;
    int pktlen;
{
    u_char *inp;
    u_char code, id;
    u_short len;
 
    cbcp_state *us = &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 */
void cbcp_protrej(int iface)
{
}
 
char *cbcp_codenames[] = {
    "Request", "Response", "Ack"
};
 
char *cbcp_optionnames[] = {
    "NoCallback",
    "UserDefined",
    "AdminDefined",
    "List"
};
 
/* pretty print a packet */
static int
cbcp_printpkt(p, plen, printer, arg)
    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 */
static void
cbcp_recvreq(us, pckt, pcktlen)
    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);
}
 
static void
cbcp_resp(us)
    cbcp_state *us;
{
    u_char cb_type;
    u_char buf[256];
    u_char *bufp = buf;
    int len = 0;
 
    cb_type = us->us_allowed & us->us_type;
    syslog(LOG_DEBUG, "cbcp_resp cb_type=%d", cb_type);
 
#if 0
    if (!cb_type)
        lcp_down(us->us_unit);
#endif
 
    if (cb_type & ( 1 << CB_CONF_USER ) ) {
        syslog(LOG_DEBUG, "cbcp_resp CONF_USER");
        PUTCHAR(CB_CONF_USER, bufp);
        len = 3 + 1 + strlen(us->us_number) + 1;
        PUTCHAR(len , bufp);
        PUTCHAR(5, bufp); /* delay */
        PUTCHAR(1, bufp);
        BCOPY(us->us_number, bufp, strlen(us->us_number) + 1);
        cbcp_send(us, CBCP_RESP, buf, len);
        return;
    }
 
    if (cb_type & ( 1 << CB_CONF_ADMIN ) ) {
        syslog(LOG_DEBUG, "cbcp_resp CONF_ADMIN");
        PUTCHAR(CB_CONF_ADMIN, bufp);
        len = 3 + 1;
        PUTCHAR(len , bufp);
        PUTCHAR(5, bufp); /* delay */
        PUTCHAR(0, 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 = 3;
        PUTCHAR(len , bufp);
        PUTCHAR(0, bufp);
        cbcp_send(us, CBCP_RESP, buf, len);
        (*ipcp_protent.open)(us->us_unit);
        return;
    }
}
 
static void
cbcp_send(us, code, buf, len)
    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(us->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
}
 
static void
cbcp_recvack(us, pckt, len)
    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);
}
 
extern int persist;
 
/* ok peer will do callback */
static void
cbcp_up(us)
    cbcp_state *us;
{
    persist = 0;
    lcp_close(0, "Call me back, please");
}

Browse

Tools

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [pppd/] [cbcp.c] - Blame information for rev 30

Line No.	Rev	Author	Line
1	30	unneback	`/*`
2			`* cbcp - Call Back Configuration Protocol.`
3			`*`
4			`* Copyright (c) 1995 Pedro Roque Marques`
5			`* All rights reserved.`
6			`*`
7			`* Redistribution and use in source and binary forms are permitted`
8			`* provided that the above copyright notice and this paragraph are`
9			`* duplicated in all such forms and that any documentation,`
10			`* advertising materials, and other materials related to such`
11			`* distribution and use acknowledge that the software was developed`
12			`* by Pedro Roque Marques. The name of the author may not be used to`
13			`* endorse or promote products derived from this software without`
14			`* specific prior written permission.`
15			`*`
16			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17			`* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED`
18			`* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.`
19			`*/`
20
21			`#ifndef lint`
22			`/* static char rcsid[] = "$Id: cbcp.c,v 1.2 2001-09-27 12:01:57 chris Exp $"; */`
23			`#endif`
24
25			`#include <stdio.h>`
26			`#include <string.h>`
27			`#include <sys/types.h>`
28			`#include <sys/time.h>`
29			`#include <syslog.h>`
30
31			`#include "pppd.h"`
32			`#include "cbcp.h"`
33			`#include "fsm.h"`
34			`#include "lcp.h"`
35			`#include "ipcp.h"`
36
37			`/*`
38			`* Protocol entry points.`
39			`*/`
40			`static void cbcp_init __P((int unit));`
41			`static void cbcp_open __P((int unit));`
42			`static void cbcp_lowerup __P((int unit));`
43			`static void cbcp_input __P((int unit, u_char *pkt, int len));`
44			`static void cbcp_protrej __P((int unit));`
45			`static int cbcp_printpkt __P((u_char *pkt, int len,`
46			`void (printer) __P((void , char *, ...)),`
47			`void *arg));`
48
49			`struct protent cbcp_protent = {`
50			`PPP_CBCP,`
51			`cbcp_init,`
52			`cbcp_input,`
53			`cbcp_protrej,`
54			`cbcp_lowerup,`
55			`NULL,`
56			`cbcp_open,`
57			`NULL,`
58			`cbcp_printpkt,`
59			`NULL,`
60			`0,`
61			`"CBCP",`
62			`NULL,`
63			`NULL,`
64			`NULL`
65			`};`
66
67			`cbcp_state cbcp[NUM_PPP];`
68
69			`/* internal prototypes */`
70
71			`static void cbcp_recvreq __P((cbcp_state us, char pckt, int len));`
72			`static void cbcp_resp __P((cbcp_state *us));`
73			`static void cbcp_up __P((cbcp_state *us));`
74			`static void cbcp_recvack __P((cbcp_state us, char pckt, int len));`
75			`static void cbcp_send __P((cbcp_state us, u_char code, u_char buf, int len));`
76
77			`/* init state */`
78			`static void`
79			`cbcp_init(iface)`
80			`int iface;`
81			`{`
82			`cbcp_state *us;`
83
84			`us = &cbcp[iface];`
85			`memset(us, 0, sizeof(cbcp_state));`
86			`us->us_unit = iface;`
87			`us->us_type \|= (1 << CB_CONF_NO);`
88			`}`
89
90			`/* lower layer is up */`
91			`static void`
92			`cbcp_lowerup(iface)`
93			`int iface;`
94			`{`
95			`cbcp_state *us = &cbcp[iface];`
96
97
98			`syslog(LOG_DEBUG, "cbcp_lowerup");`
99			`syslog(LOG_DEBUG, "want: %d", us->us_type);`
100
101			`if (us->us_type == CB_CONF_USER)`
102			`syslog(LOG_DEBUG, "phone no: %s", us->us_number);`
103			`}`
104
105			`static void`
106			`cbcp_open(unit)`
107			`int unit;`
108			`{`
109			`syslog(LOG_DEBUG, "cbcp_open");`
110			`}`
111
112			`/* process an incomming packet */`
113			`static void`
114			`cbcp_input(unit, inpacket, pktlen)`
115			`int unit;`
116			`u_char *inpacket;`
117			`int pktlen;`
118			`{`
119			`u_char *inp;`
120			`u_char code, id;`
121			`u_short len;`
122
123			`cbcp_state *us = &cbcp[unit];`
124
125			`inp = inpacket;`
126
127			`if (pktlen < CBCP_MINLEN) {`
128			`syslog(LOG_ERR, "CBCP packet is too small");`
129			`return;`
130			`}`
131
132			`GETCHAR(code, inp);`
133			`GETCHAR(id, inp);`
134			`GETSHORT(len, inp);`
135
136			`#if 0`
137			`if (len > pktlen) {`
138			`syslog(LOG_ERR, "CBCP packet: invalid length");`
139			`return;`
140			`}`
141			`#endif`
142
143			`len -= CBCP_MINLEN;`
144
145			`switch(code) {`
146			`case CBCP_REQ:`
147			`us->us_id = id;`
148			`cbcp_recvreq(us, inp, len);`
149			`break;`
150
151			`case CBCP_RESP:`
152			`syslog(LOG_DEBUG, "CBCP_RESP received");`
153			`break;`
154
155			`case CBCP_ACK:`
156			`if (id != us->us_id)`
157			`syslog(LOG_DEBUG, "id doesn't match: expected %d recv %d",`
158			`us->us_id, id);`
159
160			`cbcp_recvack(us, inp, len);`
161			`break;`
162
163			`default:`
164			`break;`
165			`}`
166			`}`
167
168			`/* protocol was rejected by foe */`
169			`void cbcp_protrej(int iface)`
170			`{`
171			`}`
172
173			`char *cbcp_codenames[] = {`
174			`"Request", "Response", "Ack"`
175			`};`
176
177			`char *cbcp_optionnames[] = {`
178			`"NoCallback",`
179			`"UserDefined",`
180			`"AdminDefined",`
181			`"List"`
182			`};`
183
184			`/* pretty print a packet */`
185			`static int`
186			`cbcp_printpkt(p, plen, printer, arg)`
187			`u_char *p;`
188			`int plen;`
189			`void (printer) __P((void , char *, ...));`
190			`void *arg;`
191			`{`
192			`int code, opt, id, len, olen, delay;`
193			`u_char *pstart;`
194
195			`if (plen < HEADERLEN)`
196			`return 0;`
197			`pstart = p;`
198			`GETCHAR(code, p);`
199			`GETCHAR(id, p);`
200			`GETSHORT(len, p);`
201			`if (len < HEADERLEN \|\| len > plen)`
202			`return 0;`
203
204			`if (code >= 1 && code <= sizeof(cbcp_codenames) / sizeof(char *))`
205			`printer(arg, " %s", cbcp_codenames[code-1]);`
206			`else`
207			`printer(arg, " code=0x%x", code);`
208
209			`printer(arg, " id=0x%x", id);`
210			`len -= HEADERLEN;`
211
212			`switch (code) {`
213			`case CBCP_REQ:`
214			`case CBCP_RESP:`
215			`case CBCP_ACK:`
216			`while(len >= 2) {`
217			`GETCHAR(opt, p);`
218			`GETCHAR(olen, p);`
219
220			`if (olen < 2 \|\| olen > len) {`
221			`break;`
222			`}`
223
224			`printer(arg, " <");`
225			`len -= olen;`
226
227			`if (opt >= 1 && opt <= sizeof(cbcp_optionnames) / sizeof(char *))`
228			`printer(arg, " %s", cbcp_optionnames[opt-1]);`
229			`else`
230			`printer(arg, " option=0x%x", opt);`
231
232			`if (olen > 2) {`
233			`GETCHAR(delay, p);`
234			`printer(arg, " delay = %d", delay);`
235			`}`
236
237			`if (olen > 3) {`
238			`int addrt;`
239			`char str[256];`
240
241			`GETCHAR(addrt, p);`
242			`memcpy(str, p, olen - 4);`
243			`str[olen - 4] = 0;`
244			`printer(arg, " number = %s", str);`
245			`}`
246			`printer(arg, ">");`
247			`break;`
248			`}`
249
250			`default:`
251			`break;`
252			`}`
253
254			`for (; len > 0; --len) {`
255			`GETCHAR(code, p);`
256			`printer(arg, " %.2x", code);`
257			`}`
258
259			`return p - pstart;`
260			`}`
261
262			`/* received CBCP request */`
263			`static void`
264			`cbcp_recvreq(us, pckt, pcktlen)`
265			`cbcp_state *us;`
266			`char *pckt;`
267			`int pcktlen;`
268			`{`
269			`u_char type, opt_len, delay, addr_type;`
270			`char address[256];`
271			`int len = pcktlen;`
272
273			`address[0] = 0;`
274
275			`while (len) {`
276			`syslog(LOG_DEBUG, "length: %d", len);`
277
278			`GETCHAR(type, pckt);`
279			`GETCHAR(opt_len, pckt);`
280
281			`if (opt_len > 2)`
282			`GETCHAR(delay, pckt);`
283
284			`us->us_allowed \|= (1 << type);`
285
286			`switch(type) {`
287			`case CB_CONF_NO:`
288			`syslog(LOG_DEBUG, "no callback allowed");`
289			`break;`
290
291			`case CB_CONF_USER:`
292			`syslog(LOG_DEBUG, "user callback allowed");`
293			`if (opt_len > 4) {`
294			`GETCHAR(addr_type, pckt);`
295			`memcpy(address, pckt, opt_len - 4);`
296			`address[opt_len - 4] = 0;`
297			`if (address[0])`
298			`syslog(LOG_DEBUG, "address: %s", address);`
299			`}`
300			`break;`
301
302			`case CB_CONF_ADMIN:`
303			`syslog(LOG_DEBUG, "user admin defined allowed");`
304			`break;`
305
306			`case CB_CONF_LIST:`
307			`break;`
308			`}`
309			`len -= opt_len;`
310			`}`
311
312			`cbcp_resp(us);`
313			`}`
314
315			`static void`
316			`cbcp_resp(us)`
317			`cbcp_state *us;`
318			`{`
319			`u_char cb_type;`
320			`u_char buf[256];`
321			`u_char *bufp = buf;`
322			`int len = 0;`
323
324			`cb_type = us->us_allowed & us->us_type;`
325			`syslog(LOG_DEBUG, "cbcp_resp cb_type=%d", cb_type);`
326
327			`#if 0`
328			`if (!cb_type)`
329			`lcp_down(us->us_unit);`
330			`#endif`
331
332			`if (cb_type & ( 1 << CB_CONF_USER ) ) {`
333			`syslog(LOG_DEBUG, "cbcp_resp CONF_USER");`
334			`PUTCHAR(CB_CONF_USER, bufp);`
335			`len = 3 + 1 + strlen(us->us_number) + 1;`
336			`PUTCHAR(len , bufp);`
337			`PUTCHAR(5, bufp); /* delay */`
338			`PUTCHAR(1, bufp);`
339			`BCOPY(us->us_number, bufp, strlen(us->us_number) + 1);`
340			`cbcp_send(us, CBCP_RESP, buf, len);`
341			`return;`
342			`}`
343
344			`if (cb_type & ( 1 << CB_CONF_ADMIN ) ) {`
345			`syslog(LOG_DEBUG, "cbcp_resp CONF_ADMIN");`
346			`PUTCHAR(CB_CONF_ADMIN, bufp);`
347			`len = 3 + 1;`
348			`PUTCHAR(len , bufp);`
349			`PUTCHAR(5, bufp); /* delay */`
350			`PUTCHAR(0, bufp);`
351			`cbcp_send(us, CBCP_RESP, buf, len);`
352			`return;`
353			`}`
354
355			`if (cb_type & ( 1 << CB_CONF_NO ) ) {`
356			`syslog(LOG_DEBUG, "cbcp_resp CONF_NO");`
357			`PUTCHAR(CB_CONF_NO, bufp);`
358			`len = 3;`
359			`PUTCHAR(len , bufp);`
360			`PUTCHAR(0, bufp);`
361			`cbcp_send(us, CBCP_RESP, buf, len);`
362			`(*ipcp_protent.open)(us->us_unit);`
363			`return;`
364			`}`
365			`}`
366
367			`static void`
368			`cbcp_send(us, code, buf, len)`
369			`cbcp_state *us;`
370			`u_char code;`
371			`u_char *buf;`
372			`int len;`
373			`{`
374			`u_char *outp;`
375			`int outlen;`
376
377			`outp = outpacket_buf;`
378
379			`outlen = 4 + len;`
380
381			`MAKEHEADER(outp, PPP_CBCP);`
382
383			`PUTCHAR(code, outp);`
384			`PUTCHAR(us->us_id, outp);`
385			`PUTSHORT(outlen, outp);`
386
387			`if (len)`
388			`BCOPY(buf, outp, len);`
389
390			`output(us->us_unit, outpacket_buf, outlen + PPP_HDRLEN);`
391			`}`
392
393			`static void`
394			`cbcp_recvack(us, pckt, len)`
395			`cbcp_state *us;`
396			`char *pckt;`
397			`int len;`
398			`{`
399			`u_char type, delay, addr_type;`
400			`int opt_len;`
401			`char address[256];`
402
403			`if (len) {`
404			`GETCHAR(type, pckt);`
405			`GETCHAR(opt_len, pckt);`
406
407			`if (opt_len > 2)`
408			`GETCHAR(delay, pckt);`
409
410			`if (opt_len > 4) {`
411			`GETCHAR(addr_type, pckt);`
412			`memcpy(address, pckt, opt_len - 4);`
413			`address[opt_len - 4] = 0;`
414			`if (address[0])`
415			`syslog(LOG_DEBUG, "peer will call: %s", address);`
416			`}`
417			`}`
418
419			`cbcp_up(us);`
420			`}`
421
422			`extern int persist;`
423
424			`/* ok peer will do callback */`
425			`static void`
426			`cbcp_up(us)`
427			`cbcp_state *us;`
428			`{`
429			`persist = 0;`
430			`lcp_close(0, "Call me back, please");`
431			`}`