/* $NetBSD: lcp.c,v 1.6 2025/01/08 19:59:39 christos Exp $ */
/*
* lcp.c - PPP Link Control Protocol.
*
* Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Office of Technology Transfer
* Carnegie Mellon University
* 5000 Forbes Avenue
* Pittsburgh, PA 15213-3890
* (412) 268-4387, fax: (412) 268-7395
*
[email protected]
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (
http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: lcp.c,v 1.6 2025/01/08 19:59:39 christos Exp $");
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <arpa/inet.h>
#include <sys/mman.h>
#include "pppd-private.h"
#include "options.h"
#include "fsm.h"
#include "lcp.h"
#include "eap.h"
#include "chap.h"
#include "magic.h"
#include "multilink.h"
/*
* When the link comes up we want to be able to wait for a short while,
* or until seeing some input from the peer, before starting to send
* configure-requests. We do this by delaying the fsm_lowerup call.
*/
/* steal a bit in fsm flags word */
#define DELAYED_UP 0x100
static void lcp_delayed_up(void *);
/*
* These definitions relate to the measurement and logging of round-trip
* time (RTT) of LCP echo-requests implemented in lcp_rtt_update_buffer().
*/
#define LCP_RTT_MAGIC 0x19450425
#define LCP_RTT_HEADER_LENGTH 4
#define LCP_RTT_FILE_SIZE 8192
#define LCP_RTT_ELEMENTS (LCP_RTT_FILE_SIZE / sizeof(u_int32_t) - LCP_RTT_HEADER_LENGTH) / 2
/*
* LCP-related command-line options.
*/
int lcp_echo_interval = 0; /* Interval between LCP echo-requests */
int lcp_echo_fails = 0; /* Tolerance to unanswered echo-requests */
bool lcp_echo_adaptive = 0; /* request echo only if the link was idle */
char *lcp_rtt_file = NULL; /* measure the RTT of LCP echo-requests */
bool lax_recv = 0; /* accept control chars in asyncmap */
bool noendpoint = 0; /* don't send/accept endpoint discriminator */
static int noopt(char **);
#ifdef PPP_WITH_MULTILINK
static int setendpoint(char **);
static void printendpoint(option_t *, void (*)(void *, char *, ...), void *);
#endif /* PPP_WITH_MULTILINK */
static struct option lcp_option_list[] = {
/* LCP options */
{ "-all", o_special_noarg, (void *)noopt,
"Don't request/allow any LCP options" },
{ "noaccomp", o_bool, &lcp_wantoptions[0].neg_accompression,
"Disable address/control compression",
OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
{ "-ac", o_bool, &lcp_wantoptions[0].neg_accompression,
"Disable address/control compression",
OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
{ "asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
"Set asyncmap (for received packets)",
OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
{ "-as", o_uint32, &lcp_wantoptions[0].asyncmap,
"Set asyncmap (for received packets)",
OPT_ALIAS | OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
{ "default-asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
"Disable asyncmap negotiation",
OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
&lcp_allowoptions[0].neg_asyncmap },
{ "-am", o_uint32, &lcp_wantoptions[0].asyncmap,
"Disable asyncmap negotiation",
OPT_ALIAS | OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
&lcp_allowoptions[0].neg_asyncmap },
{ "nomagic", o_bool, &lcp_wantoptions[0].neg_magicnumber,
"Disable magic number negotiation (looped-back line detection)",
OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
{ "-mn", o_bool, &lcp_wantoptions[0].neg_magicnumber,
"Disable magic number negotiation (looped-back line detection)",
OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
{ "mru", o_int, &lcp_wantoptions[0].mru,
"Set MRU (maximum received packet size) for negotiation",
OPT_PRIO, &lcp_wantoptions[0].neg_mru },
{ "default-mru", o_bool, &lcp_wantoptions[0].neg_mru,
"Disable MRU negotiation (use default 1500)",
OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
{ "-mru", o_bool, &lcp_wantoptions[0].neg_mru,
"Disable MRU negotiation (use default 1500)",
OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
{ "mtu", o_int, &lcp_allowoptions[0].mru,
"Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU },
{ "nopcomp", o_bool, &lcp_wantoptions[0].neg_pcompression,
"Disable protocol field compression",
OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
{ "-pc", o_bool, &lcp_wantoptions[0].neg_pcompression,
"Disable protocol field compression",
OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
{ "passive", o_bool, &lcp_wantoptions[0].passive,
"Set passive mode", 1 },
{ "-p", o_bool, &lcp_wantoptions[0].passive,
"Set passive mode", OPT_ALIAS | 1 },
{ "silent", o_bool, &lcp_wantoptions[0].silent,
"Set silent mode", 1 },
{ "lcp-echo-failure", o_int, &lcp_echo_fails,
"Set number of consecutive echo failures to indicate link failure",
OPT_PRIO },
{ "lcp-echo-interval", o_int, &lcp_echo_interval,
"Set time in seconds between LCP echo requests", OPT_PRIO },
{ "lcp-echo-adaptive", o_bool, &lcp_echo_adaptive,
"Suppress LCP echo requests if traffic was received", 1 },
{ "lcp-rtt-file", o_string, &lcp_rtt_file,
"Filename for logging the round-trip time of LCP echo requests",
OPT_PRIO | OPT_PRIV },
{ "lcp-restart", o_int, &lcp_fsm[0].timeouttime,
"Set time in seconds between LCP retransmissions", OPT_PRIO },
{ "lcp-max-terminate", o_int, &lcp_fsm[0].maxtermtransmits,
"Set maximum number of LCP terminate-request transmissions", OPT_PRIO },
{ "lcp-max-configure", o_int, &lcp_fsm[0].maxconfreqtransmits,
"Set maximum number of LCP configure-request transmissions", OPT_PRIO },
{ "lcp-max-failure", o_int, &lcp_fsm[0].maxnakloops,
"Set limit on number of LCP configure-naks", OPT_PRIO },
{ "receive-all", o_bool, &lax_recv,
"Accept all received control characters", 1 },
#ifdef PPP_WITH_MULTILINK
{ "mrru", o_int, &lcp_wantoptions[0].mrru,
"Maximum received packet size for multilink bundle",
OPT_PRIO, &lcp_wantoptions[0].neg_mrru },
{ "mpshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
"Use short sequence numbers in multilink headers",
OPT_PRIO | 1, &lcp_allowoptions[0].neg_ssnhf },
{ "nompshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
"Don't use short sequence numbers in multilink headers",
OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_ssnhf },
{ "endpoint", o_special, (void *) setendpoint,
"Endpoint discriminator for multilink",
OPT_PRIO | OPT_A2PRINTER, (void *) printendpoint },
#endif /* PPP_WITH_MULTILINK */
{ "noendpoint", o_bool, &noendpoint,
"Don't send or accept multilink endpoint discriminator", 1 },
{NULL}
};
/* global vars */
fsm lcp_fsm[NUM_PPP]; /* LCP fsm structure (global)*/
lcp_options lcp_wantoptions[NUM_PPP]; /* Options that we want to request */
lcp_options lcp_gotoptions[NUM_PPP]; /* Options that peer ack'd */
lcp_options lcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
lcp_options lcp_hisoptions[NUM_PPP]; /* Options that we ack'd */
static int lcp_echos_pending = 0; /* Number of outstanding echo msgs */
static int lcp_echo_number = 0; /* ID number of next echo frame */
static int lcp_echo_timer_running = 0; /* set if a timer is running */
static int lcp_rtt_file_fd = 0; /* fd for the opened LCP RTT file */
static u_int32_t *lcp_rtt_buffer = NULL; /* the mmap'ed LCP RTT file */
static u_char nak_buffer[PPP_MRU]; /* where we construct a nak packet */
/*
* Callbacks for fsm code. (CI = Configuration Information)
*/
static void lcp_resetci(fsm *); /* Reset our CI */
static int lcp_cilen(fsm *); /* Return length of our CI */
static void lcp_addci(fsm *, u_char *, int *); /* Add our CI to pkt */
static int lcp_ackci(fsm *, u_char *, int); /* Peer ack'd our CI */
static int lcp_nakci(fsm *, u_char *, int, int); /* Peer nak'd our CI */
static int lcp_rejci(fsm *, u_char *, int); /* Peer rej'd our CI */
static int lcp_reqci(fsm *, u_char *, int *, int); /* Rcv peer CI */
static void lcp_up(fsm *); /* We're UP */
static void lcp_down(fsm *); /* We're DOWN */
static void lcp_starting(fsm *); /* We need lower layer up */
static void lcp_finished(fsm *); /* We need lower layer down */
static int lcp_extcode(fsm *, int, int, u_char *, int);
static void lcp_rprotrej(fsm *, u_char *, int);
/*
* routines to send LCP echos to peer
*/
static void lcp_echo_lowerup(int);
static void lcp_echo_lowerdown(int);
static void LcpEchoTimeout(void *);
static void lcp_received_echo_reply(fsm *, int, u_char *, int);
static void LcpSendEchoRequest(fsm *);
static void LcpLinkFailure(fsm *);
static void LcpEchoCheck(fsm *);
static fsm_callbacks lcp_callbacks = { /* LCP callback routines */
lcp_resetci, /* Reset our Configuration Information */
lcp_cilen, /* Length of our Configuration Information */
lcp_addci, /* Add our Configuration Information */
lcp_ackci, /* ACK our Configuration Information */
lcp_nakci, /* NAK our Configuration Information */
lcp_rejci, /* Reject our Configuration Information */
lcp_reqci, /* Request peer's Configuration Information */
lcp_up, /* Called when fsm reaches OPENED state */
lcp_down, /* Called when fsm leaves OPENED state */
lcp_starting, /* Called when we want the lower layer up */
lcp_finished, /* Called when we want the lower layer down */
NULL, /* Called when Protocol-Reject received */
NULL, /* Retransmission is necessary */
lcp_extcode, /* Called to handle LCP-specific codes */
"LCP" /* String name of protocol */
};
/*
* Protocol entry points.
* Some of these are called directly.
*/
static void lcp_init(int);
static void lcp_input(int, u_char *, int);
static void lcp_protrej(int);
static int lcp_printpkt(u_char *, int, void (*)(void *, char *, ...), void *);
struct protent lcp_protent = {
PPP_LCP,
lcp_init,
lcp_input,
lcp_protrej,
lcp_lowerup,
lcp_lowerdown,
lcp_open,
lcp_close,
lcp_printpkt,
NULL,
1,
"LCP",
NULL,
lcp_option_list,
NULL,
NULL,
NULL
};
int lcp_loopbackfail = DEFLOOPBACKFAIL;
/*
* Length of each type of configuration option (in octets)
*/
#define CILEN_VOID 2
#define CILEN_CHAR 3
#define CILEN_SHORT 4 /* CILEN_VOID + 2 */
#define CILEN_CHAP 5 /* CILEN_VOID + 2 + 1 */
#define CILEN_LONG 6 /* CILEN_VOID + 4 */
#define CILEN_LQR 8 /* CILEN_VOID + 2 + 4 */
#define CILEN_CBCP 3
#define CODENAME(x) ((x) == CONFACK ? "ACK" : \
(x) == CONFNAK ? "NAK" : "REJ")
/*
* noopt - Disable all options (why?).
*/
static int
noopt(char **argv)
{
BZERO((char *) &lcp_wantoptions[0], sizeof (struct lcp_options));
BZERO((char *) &lcp_allowoptions[0], sizeof (struct lcp_options));
return (1);
}
#ifdef PPP_WITH_MULTILINK
static int
setendpoint(char **argv)
{
if (str_to_epdisc(&lcp_wantoptions[0].endpoint, *argv)) {
lcp_wantoptions[0].neg_endpoint = 1;
return 1;
}
ppp_option_error("Can't parse '%s' as an endpoint discriminator", *argv);
return 0;
}
static void
printendpoint(option_t *opt, void (*printer)(void *, char *, ...), void *arg)
{
printer(arg, "%s", epdisc_to_str(&lcp_wantoptions[0].endpoint));
}
#endif /* PPP_WITH_MULTILINK */
/*
* lcp_init - Initialize LCP.
*/
static void
lcp_init(int unit)
{
fsm *f = &lcp_fsm[unit];
lcp_options *wo = &lcp_wantoptions[unit];
lcp_options *ao = &lcp_allowoptions[unit];
f->unit = unit;
f->protocol = PPP_LCP;
f->callbacks = &lcp_callbacks;
fsm_init(f);
BZERO(wo, sizeof(*wo));
wo->neg_mru = 1;
wo->mru = DEFMRU;
wo->neg_asyncmap = 1;
wo->neg_magicnumber = 1;
wo->neg_pcompression = 1;
wo->neg_accompression = 1;
BZERO(ao, sizeof(*ao));
ao->neg_mru = 1;
ao->mru = MAXMRU;
ao->neg_asyncmap = 1;
ao->neg_chap = 1;
ao->chap_mdtype = chap_mdtype_all;
ao->neg_upap = 1;
ao->neg_eap = 1;
ao->neg_magicnumber = 1;
ao->neg_pcompression = 1;
ao->neg_accompression = 1;
ao->neg_endpoint = 1;
}
/*
* lcp_open - LCP is allowed to come up.
*/
void
lcp_open(int unit)
{
fsm *f = &lcp_fsm[unit];
lcp_options *wo = &lcp_wantoptions[unit];
f->flags &= ~(OPT_PASSIVE | OPT_SILENT);
if (wo->passive)
f->flags |= OPT_PASSIVE;
if (wo->silent)
f->flags |= OPT_SILENT;
fsm_open(f);
}
/*
* lcp_close - Take LCP down.
*/
void
lcp_close(int unit, char *reason)
{
fsm *f = &lcp_fsm[unit];
int oldstate;
if (!in_phase(PHASE_DEAD) && !in_phase(PHASE_MASTER))
new_phase(PHASE_TERMINATE);
if (f->flags & DELAYED_UP) {
UNTIMEOUT(lcp_delayed_up, f);
f->state = STOPPED;
}
oldstate = f->state;
fsm_close(f, reason);
if (oldstate == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT|DELAYED_UP)) {
/*
* This action is not strictly according to the FSM in RFC1548,
* but it does mean that the program terminates if you do a
* lcp_close() when a connection hasn't been established
* because we are in passive/silent mode or because we have
* delayed the fsm_lowerup() call and it hasn't happened yet.
*/
f->flags &= ~DELAYED_UP;
lcp_finished(f);
}
}
/*
* lcp_lowerup - The lower layer is up.
*/
void
lcp_lowerup(int unit)
{
lcp_options *wo = &lcp_wantoptions[unit];
fsm *f = &lcp_fsm[unit];
/*
* Don't use A/C or protocol compression on transmission,
* but accept A/C and protocol compressed packets
* if we are going to ask for A/C and protocol compression.
*/
if (ppp_send_config(unit, PPP_MRU, 0xffffffff, 0, 0) < 0
|| ppp_recv_config(unit, PPP_MRU, (lax_recv? 0: 0xffffffff),
wo->neg_pcompression, wo->neg_accompression) < 0)
return;
peer_mru[unit] = PPP_MRU;
if (listen_time != 0) {
f->flags |= DELAYED_UP;
ppp_timeout(lcp_delayed_up, f, 0, listen_time * 1000);
} else
fsm_lowerup(f);
}
/*
* lcp_lowerdown - The lower layer is down.
*/
void
lcp_lowerdown(int unit)
{
fsm *f = &lcp_fsm[unit];
if (f->flags & DELAYED_UP) {
f->flags &= ~DELAYED_UP;
UNTIMEOUT(lcp_delayed_up, f);
} else
fsm_lowerdown(&lcp_fsm[unit]);
}
/*
* lcp_delayed_up - Bring the lower layer up now.
*/
static void
lcp_delayed_up(void *arg)
{
fsm *f = arg;
if (f->flags & DELAYED_UP) {
f->flags &= ~DELAYED_UP;
fsm_lowerup(f);
}
}
/*
* lcp_input - Input LCP packet.
*/
static void
lcp_input(int unit, u_char *p, int len)
{
fsm *f = &lcp_fsm[unit];
if (f->flags & DELAYED_UP) {
f->flags &= ~DELAYED_UP;
UNTIMEOUT(lcp_delayed_up, f);
fsm_lowerup(f);
}
fsm_input(f, p, len);
}
/*
* lcp_extcode - Handle a LCP-specific code.
*/
static int
lcp_extcode(fsm *f, int code, int id, u_char *inp, int len)
{
u_char *magp;
switch( code ){
case PROTREJ:
lcp_rprotrej(f, inp, len);
break;
case ECHOREQ:
if (f->state != OPENED)
break;
magp = inp;
PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);
fsm_sdata(f, ECHOREP, id, inp, len);
break;
case ECHOREP:
lcp_received_echo_reply(f, id, inp, len);
break;
case DISCREQ:
case IDENTIF:
case TIMEREM:
break;
default:
return 0;
}
return 1;
}
/*
* lcp_rprotrej - Receive an Protocol-Reject.
*
* Figure out which protocol is rejected and inform it.
*/
static void
lcp_rprotrej(fsm *f, u_char *inp, int len)
{
int i;
struct protent *protp;
u_short prot;
const char *pname;
if (len < 2) {
LCPDEBUG(("lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
return;
}
GETSHORT(prot, inp);
/*
* Protocol-Reject packets received in any state other than the LCP
* OPENED state SHOULD be silently discarded.
*/
if( f->state != OPENED ){
LCPDEBUG(("Protocol-Reject discarded: LCP in state %d", f->state));
return;
}
pname = protocol_name(prot);
/*
* Upcall the proper Protocol-Reject routine.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->protocol == prot && protp->enabled_flag) {
if (pname == NULL)
dbglog("Protocol-Reject for 0x%x received", prot);
else
dbglog("Protocol-Reject for '%s' (0x%x) received", pname,
prot);
(*protp->protrej)(f->unit);
return;
}
if (pname == NULL)
warn("Protocol-Reject for unsupported protocol 0x%x", prot);
else
warn("Protocol-Reject for unsupported protocol '%s' (0x%x)", pname,
prot);
}
/*
* lcp_protrej - A Protocol-Reject was received.
*/
/*ARGSUSED*/
static void
lcp_protrej(int unit)
{
/*
* Can't reject LCP!
*/
error("Received Protocol-Reject for LCP!");
fsm_protreject(&lcp_fsm[unit]);
}
/*
* lcp_sprotrej - Send a Protocol-Reject for some protocol.
*/
void
lcp_sprotrej(int unit, u_char *p, int len)
{
/*
* Send back the protocol and the information field of the
* rejected packet. We only get here if LCP is in the OPENED state.
*/
p += 2;
len -= 2;
fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
p, len);
}
/*
* lcp_resetci - Reset our CI.
*/
static void
lcp_resetci(fsm *f)
{
lcp_options *wo = &lcp_wantoptions[f->unit];
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *ao = &lcp_allowoptions[f->unit];
wo->magicnumber = magic();
wo->numloops = 0;
*go = *wo;
if (!multilink) {
go->neg_mrru = 0;
go->neg_ssnhf = 0;
go->neg_endpoint = 0;
}
if (noendpoint)
ao->neg_endpoint = 0;
peer_mru[f->unit] = PPP_MRU;
auth_reset(f->unit);
}
/*
* lcp_cilen - Return length of our CI.
*/
static int
lcp_cilen(fsm *f)
{
lcp_options *go = &lcp_gotoptions[f->unit];
#define LENCIVOID(neg) ((neg) ? CILEN_VOID : 0)
#define LENCICHAP(neg) ((neg) ? CILEN_CHAP : 0)
#define LENCISHORT(neg) ((neg) ? CILEN_SHORT : 0)
#define LENCILONG(neg) ((neg) ? CILEN_LONG : 0)
#define LENCILQR(neg) ((neg) ? CILEN_LQR: 0)
#define LENCICBCP(neg) ((neg) ? CILEN_CBCP: 0)
/*
* NB: we only ask for one of CHAP, UPAP, or EAP, even if we will
* accept more than one. We prefer EAP first, then CHAP, then
* PAP.
*/
return (LENCISHORT(go->neg_mru && go->mru != DEFMRU) +
LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) +
LENCISHORT(go->neg_eap) +
LENCICHAP(!go->neg_eap && go->neg_chap) +
LENCISHORT(!go->neg_eap && !go->neg_chap && go->neg_upap) +
LENCILQR(go->neg_lqr) +
LENCICBCP(go->neg_cbcp) +
LENCILONG(go->neg_magicnumber) +
LENCIVOID(go->neg_pcompression) +
LENCIVOID(go->neg_accompression) +
LENCISHORT(go->neg_mrru) +
LENCIVOID(go->neg_ssnhf) +
(go->neg_endpoint? CILEN_CHAR + go->endpoint.length: 0));
}
/*
* lcp_addci - Add our desired CIs to a packet.
*/
static void
lcp_addci(fsm *f, u_char *ucp, int *lenp)
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char *start_ucp = ucp;
#define ADDCIVOID(opt, neg) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_VOID, ucp); \
}
#define ADDCISHORT(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_SHORT, ucp); \
PUTSHORT(val, ucp); \
}
#define ADDCICHAP(opt, neg, val) \
if (neg) { \
PUTCHAR((opt), ucp); \
PUTCHAR(CILEN_CHAP, ucp); \
PUTSHORT(PPP_CHAP, ucp); \
PUTCHAR((CHAP_DIGEST(val)), ucp); \
}
#define ADDCILONG(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_LONG, ucp); \
PUTLONG(val, ucp); \
}
#define ADDCILQR(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_LQR, ucp); \
PUTSHORT(PPP_LQR, ucp); \
PUTLONG(val, ucp); \
}
#define ADDCICHAR(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_CHAR, ucp); \
PUTCHAR(val, ucp); \
}
#define ADDCIENDP(opt, neg, class, val, len) \
if (neg) { \
int i; \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_CHAR + len, ucp); \
PUTCHAR(class, ucp); \
for (i = 0; i < len; ++i) \
PUTCHAR(val[i], ucp); \
}
ADDCISHORT(CI_MRU, go->neg_mru && go->mru != DEFMRU, go->mru);
ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
go->asyncmap);
ADDCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
ADDCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap,
PPP_PAP);
ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
ADDCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
ADDCIVOID(CI_SSNHF, go->neg_ssnhf);
ADDCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class,
go->endpoint.value, go->endpoint.length);
if (ucp - start_ucp != *lenp) {
/* this should never happen, because peer_mtu should be 1500 */
error("Bug in lcp_addci: wrong length");
}
}
/*
* lcp_ackci - Ack our CIs.
* This should not modify any state if the Ack is bad.
*
* Returns:
* 0 - Ack was bad.
* 1 - Ack was good.
*/
static int
lcp_ackci(fsm *f, u_char *p, int len)
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char cilen, citype, cichar;
u_short cishort;
u_int32_t cilong;
/*
* CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define ACKCIVOID(opt, neg) \
if (neg) { \
if ((len -= CILEN_VOID) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_VOID || \
citype != opt) \
goto bad; \
}
#define ACKCISHORT(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_SHORT) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_SHORT || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != val) \
goto bad; \
}
#define ACKCICHAR(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_CHAR) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_CHAR || \
citype != opt) \
goto bad; \
GETCHAR(cichar, p); \
if (cichar != val) \
goto bad; \
}
#define ACKCICHAP(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_CHAP) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_CHAP || \
citype != (opt)) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != PPP_CHAP) \
goto bad; \
GETCHAR(cichar, p); \
if (cichar != (CHAP_DIGEST(val))) \
goto bad; \
}
#define ACKCILONG(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_LONG) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_LONG || \
citype != opt) \
goto bad; \
GETLONG(cilong, p); \
if (cilong != val) \
goto bad; \
}
#define ACKCILQR(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_LQR) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_LQR || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != PPP_LQR) \
goto bad; \
GETLONG(cilong, p); \
if (cilong != val) \
goto bad; \
}
#define ACKCIENDP(opt, neg, class, val, vlen) \
if (neg) { \
int i; \
if ((len -= CILEN_CHAR + vlen) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_CHAR + vlen || \
citype != opt) \
goto bad; \
GETCHAR(cichar, p); \
if (cichar != class) \
goto bad; \
for (i = 0; i < vlen; ++i) { \
GETCHAR(cichar, p); \
if (cichar != val[i]) \
goto bad; \
} \
}
ACKCISHORT(CI_MRU, go->neg_mru && go->mru != DEFMRU, go->mru);
ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
go->asyncmap);
ACKCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
ACKCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap,
PPP_PAP);
ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
ACKCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
ACKCIVOID(CI_SSNHF, go->neg_ssnhf);
ACKCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class,
go->endpoint.value, go->endpoint.length);
/*
* If there are any remaining CIs, then this packet is bad.
*/
if (len != 0)
goto bad;
return (1);
bad:
LCPDEBUG(("lcp_acki: received bad Ack!"));
return (0);
}
/*
* lcp_nakci - Peer has sent a NAK for some of our CIs.
* This should not modify any state if the Nak is bad
* or if LCP is in the OPENED state.
*
* Returns:
* 0 - Nak was bad.
* 1 - Nak was good.
*/
static int
lcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
{
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *wo = &lcp_wantoptions[f->unit];
u_char citype, cichar, *next;
u_short cishort;
u_int32_t cilong;
lcp_options no; /* options we've seen Naks for */
lcp_options try; /* options to request next time */
int looped_back = 0;
int cilen;
BZERO(&no, sizeof(no));
try = *go;
/*
* Any Nak'd CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define NAKCIVOID(opt, neg) \
if (go->neg && \
len >= CILEN_VOID && \
p[1] == CILEN_VOID && \
p[0] == opt) { \
len -= CILEN_VOID; \
INCPTR(CILEN_VOID, p); \
no.neg = 1; \
try.neg = 0; \
}
#define NAKCICHAP(opt, neg, code) \
if (go->neg && \
len >= CILEN_CHAP && \
p[1] == CILEN_CHAP && \
p[0] == opt) { \
len -= CILEN_CHAP; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETCHAR(cichar, p); \
no.neg = 1; \
code \
}
#define NAKCICHAR(opt, neg, code) \
if (go->neg && \
len >= CILEN_CHAR && \
p[1] == CILEN_CHAR && \
p[0] == opt) { \
len -= CILEN_CHAR; \
INCPTR(2, p); \
GETCHAR(cichar, p); \
no.neg = 1; \
code \
}
#define NAKCISHORT(opt, neg, code) \
if (go->neg && \
len >= CILEN_SHORT && \
p[1] == CILEN_SHORT && \
p[0] == opt) { \
len -= CILEN_SHORT; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
no.neg = 1; \
code \
}
#define NAKCILONG(opt, neg, code) \
if (go->neg && \
len >= CILEN_LONG && \
p[1] == CILEN_LONG && \
p[0] == opt) { \
len -= CILEN_LONG; \
INCPTR(2, p); \
GETLONG(cilong, p); \
no.neg = 1; \
code \
}
#define NAKCILQR(opt, neg, code) \
if (go->neg && \
len >= CILEN_LQR && \
p[1] == CILEN_LQR && \
p[0] == opt) { \
len -= CILEN_LQR; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETLONG(cilong, p); \
no.neg = 1; \
code \
}
#define NAKCIENDP(opt, neg) \
if (go->neg && \
len >= CILEN_CHAR && \
p[0] == opt && \
p[1] >= CILEN_CHAR && \
p[1] <= len) { \
len -= p[1]; \
INCPTR(p[1], p); \
no.neg = 1; \
try.neg = 0; \
}
/*
* NOTE! There must be no assignments to individual fields of *go in
* the code below. Any such assignment is a BUG!
*/
/*
* We don't care if they want to send us smaller packets than
* we want. Therefore, accept any MRU less than what we asked for,
* but then ignore the new value when setting the MRU in the kernel.
* If they send us a bigger MRU than what we asked, accept it, up to
* the limit of the default MRU we'd get if we didn't negotiate.
*/
if (go->neg_mru && go->mru != DEFMRU) {
NAKCISHORT(CI_MRU, neg_mru,
if (cishort <= wo->mru || cishort <= DEFMRU)
try.mru = cishort;
);
}
/*
* Add any characters they want to our (receive-side) asyncmap.
*/
if (go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) {
NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
try.asyncmap = go->asyncmap | cilong;
);
}
/*
* If they've nak'd our authentication-protocol, check whether
* they are proposing a different protocol, or a different
* hash algorithm for CHAP.
*/
if ((go->neg_chap || go->neg_upap || go->neg_eap)
&& len >= CILEN_SHORT
&& p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
cilen = p[1];
len -= cilen;
no.neg_chap = go->neg_chap;
no.neg_upap = go->neg_upap;
no.neg_eap = go->neg_eap;
INCPTR(2, p);
GETSHORT(cishort, p);
if (cishort == PPP_PAP && cilen == CILEN_SHORT) {
/* If we were asking for EAP, then we need to stop that. */
if (go->neg_eap)
try.neg_eap = 0;
/* If we were asking for CHAP, then we need to stop that. */
else if (go->neg_chap)
try.neg_chap = 0;
/*
* If we weren't asking for CHAP or EAP, then we were asking for
* PAP, in which case this Nak is bad.
*/
else
goto bad;
} else if (cishort == PPP_CHAP && cilen == CILEN_CHAP) {
GETCHAR(cichar, p);
/* Stop asking for EAP, if we were. */
if (go->neg_eap) {
try.neg_eap = 0;
/* Try to set up to use their suggestion, if possible */
if (CHAP_CANDIGEST(go->chap_mdtype, cichar))
try.chap_mdtype = CHAP_MDTYPE_D(cichar);
} else if (go->neg_chap) {
/*
* We were asking for our preferred algorithm, they must
* want something different.
*/
if (cichar != CHAP_DIGEST(go->chap_mdtype)) {
if (CHAP_CANDIGEST(go->chap_mdtype, cichar)) {
/* Use their suggestion if we support it ... */
try.chap_mdtype = CHAP_MDTYPE_D(cichar);
} else {
/* ... otherwise, try our next-preferred algorithm. */
try.chap_mdtype &= ~(CHAP_MDTYPE(try.chap_mdtype));
if (try.chap_mdtype == MDTYPE_NONE) /* out of algos */
try.neg_chap = 0;
}
} else {
/*
* Whoops, they Nak'd our algorithm of choice
* but then suggested it back to us.
*/
goto bad;
}
} else {
/*
* Stop asking for PAP if we were asking for it.
*/
try.neg_upap = 0;
}
} else {
/*
* If we were asking for EAP, and they're Conf-Naking EAP,
* well, that's just strange. Nobody should do that.
*/
if (cishort == PPP_EAP && cilen == CILEN_SHORT && go->neg_eap)
dbglog("Unexpected Conf-Nak for EAP");
/*
* We don't recognize what they're suggesting.
* Stop asking for what we were asking for.
*/
if (go->neg_eap)
try.neg_eap = 0;
else if (go->neg_chap)
try.neg_chap = 0;
else
try.neg_upap = 0;
p += cilen - CILEN_SHORT;
}
}
/*
* If they can't cope with our link quality protocol, we'll have
* to stop asking for LQR. We haven't got any other protocol.
* If they Nak the reporting period, take their value XXX ?
*/
NAKCILQR(CI_QUALITY, neg_lqr,
if (cishort != PPP_LQR)
try.neg_lqr = 0;
else
try.lqr_period = cilong;
);
/*
* Only implementing CBCP...not the rest of the callback options
*/
NAKCICHAR(CI_CALLBACK, neg_cbcp,
try.neg_cbcp = 0;
);
/*
* Check for a looped-back line.
*/
NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
try.magicnumber = magic();
looped_back = 1;
);
/*
* Peer shouldn't send Nak for protocol compression or
* address/control compression requests; they should send
* a Reject instead. If they send a Nak, treat it as a Reject.
*/
NAKCIVOID(CI_PCOMPRESSION, neg_pcompression);
NAKCIVOID(CI_ACCOMPRESSION, neg_accompression);
/*
* Nak for MRRU option - accept their value if it is smaller
* than the one we want.
*/
if (go->neg_mrru) {
NAKCISHORT(CI_MRRU, neg_mrru,
if (treat_as_reject)
try.neg_mrru = 0;
else if (cishort <= wo->mrru)
try.mrru = cishort;
);
}
/*
* Nak for short sequence numbers shouldn't be sent, treat it
* like a reject.
*/
NAKCIVOID(CI_SSNHF, neg_ssnhf);
/*
* Nak of the endpoint discriminator option is not permitted,
* treat it like a reject.
*/
NAKCIENDP(CI_EPDISC, neg_endpoint);
/*
* There may be remaining CIs, if the peer is requesting negotiation
* on an option that we didn't include in our request packet.
* If we see an option that we requested, or one we've already seen
* in this packet, then this packet is bad.
* If we wanted to respond by starting to negotiate on the requested
* option(s), we could, but we don't, because except for the
* authentication type and quality protocol, if we are not negotiating
* an option, it is because we were told not to.
* For the authentication type, the Nak from the peer means
* `let me authenticate myself with you' which is a bit pointless.
* For the quality protocol, the Nak means `ask me to send you quality
* reports', but if we didn't ask for them, we don't want them.
* An option we don't recognize represents the peer asking to
* negotiate some option we don't support, so ignore it.
*/
while (len >= CILEN_VOID) {
GETCHAR(citype, p);
GETCHAR(cilen, p);
if (cilen < CILEN_VOID || (len -= cilen) < 0)
goto bad;
next = p + cilen - 2;
switch (citype) {
case CI_MRU:
if ((go->neg_mru && go->mru != DEFMRU)
|| no.neg_mru || cilen != CILEN_SHORT)
goto bad;
GETSHORT(cishort, p);
if (cishort < DEFMRU) {
try.neg_mru = 1;
try.mru = cishort;
}
break;
case CI_ASYNCMAP:
if ((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF)
|| no.neg_asyncmap || cilen != CILEN_LONG)
goto bad;
break;
case CI_AUTHTYPE:
if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap ||
go->neg_eap || no.neg_eap)
goto bad;
break;
case CI_MAGICNUMBER:
if (go->neg_magicnumber || no.neg_magicnumber ||
cilen != CILEN_LONG)
goto bad;
break;
case CI_PCOMPRESSION:
if (go->neg_pcompression || no.neg_pcompression
|| cilen != CILEN_VOID)
goto bad;
break;
case CI_ACCOMPRESSION:
if (go->neg_accompression || no.neg_accompression
|| cilen != CILEN_VOID)
goto bad;
break;
case CI_QUALITY:
if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
goto bad;
break;
case CI_MRRU:
if (go->neg_mrru || no.neg_mrru || cilen != CILEN_SHORT)
goto bad;
break;
case CI_SSNHF:
if (go->neg_ssnhf || no.neg_ssnhf || cilen != CILEN_VOID)
goto bad;
try.neg_ssnhf = 1;
break;
case CI_EPDISC:
if (go->neg_endpoint || no.neg_endpoint || cilen < CILEN_CHAR)
goto bad;
break;
}
p = next;
}
/*
* OK, the Nak is good. Now we can update state.
* If there are any options left we ignore them.
*/
if (f->state != OPENED) {
if (looped_back) {
if (++try.numloops >= lcp_loopbackfail) {
notice("Serial line is looped back.");
ppp_set_status(EXIT_LOOPBACK);
lcp_close(f->unit, "Loopback detected");
}
} else
try.numloops = 0;
*go = try;
}
return 1;
bad:
LCPDEBUG(("lcp_nakci: received bad Nak!"));
return 0;
}
/*
* lcp_rejci - Peer has Rejected some of our CIs.
* This should not modify any state if the Reject is bad
* or if LCP is in the OPENED state.
*
* Returns:
* 0 - Reject was bad.
* 1 - Reject was good.
*/
static int
lcp_rejci(fsm *f, u_char *p, int len)
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char cichar;
u_short cishort;
u_int32_t cilong;
lcp_options try; /* options to request next time */
try = *go;
/*
* Any Rejected CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define REJCIVOID(opt, neg) \
if (go->neg && \
len >= CILEN_VOID && \
p[1] == CILEN_VOID && \
p[0] == opt) { \
len -= CILEN_VOID; \
INCPTR(CILEN_VOID, p); \
try.neg = 0; \
}
#define REJCISHORT(opt, neg, val) \
if (go->neg && \
len >= CILEN_SHORT && \
p[1] == CILEN_SHORT && \
p[0] == opt) { \
len -= CILEN_SHORT; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
/* Check rejected value. */ \
if (cishort != val) \
goto bad; \
try.neg = 0; \
}
#define REJCICHAP(opt, neg, val) \
if (go->neg && \
len >= CILEN_CHAP && \
p[1] == CILEN_CHAP && \
p[0] == opt) { \
len -= CILEN_CHAP; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETCHAR(cichar, p); \
/* Check rejected value. */ \
if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
goto bad; \
try.neg = 0; \
try.neg_eap = try.neg_upap = 0; \
}
#define REJCILONG(opt, neg, val) \
if (go->neg && \
len >= CILEN_LONG && \
p[1] == CILEN_LONG && \
p[0] == opt) { \
len -= CILEN_LONG; \
INCPTR(2, p); \
GETLONG(cilong, p); \
/* Check rejected value. */ \
if (cilong != val) \
goto bad; \
try.neg = 0; \
}
#define REJCILQR(opt, neg, val) \
if (go->neg && \
len >= CILEN_LQR && \
p[1] == CILEN_LQR && \
p[0] == opt) { \
len -= CILEN_LQR; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETLONG(cilong, p); \
/* Check rejected value. */ \
if (cishort != PPP_LQR || cilong != val) \
goto bad; \
try.neg = 0; \
}
#define REJCICBCP(opt, neg, val) \
if (go->neg && \
len >= CILEN_CBCP && \
p[1] == CILEN_CBCP && \
p[0] == opt) { \
len -= CILEN_CBCP; \
INCPTR(2, p); \
GETCHAR(cichar, p); \
/* Check rejected value. */ \
if (cichar != val) \
goto bad; \
try.neg = 0; \
}
#define REJCIENDP(opt, neg, class, val, vlen) \
if (go->neg && \
len >= CILEN_CHAR + vlen && \
p[0] == opt && \
p[1] == CILEN_CHAR + vlen) { \
int i; \
len -= CILEN_CHAR + vlen; \
INCPTR(2, p); \
GETCHAR(cichar, p); \
if (cichar != class) \
goto bad; \
for (i = 0; i < vlen; ++i) { \
GETCHAR(cichar, p); \
if (cichar != val[i]) \
goto bad; \
} \
try.neg = 0; \
}
REJCISHORT(CI_MRU, neg_mru, go->mru);
REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
REJCISHORT(CI_AUTHTYPE, neg_eap, PPP_EAP);
if (!go->neg_eap) {
REJCICHAP(CI_AUTHTYPE, neg_chap, go->chap_mdtype);
if (!go->neg_chap) {
REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
}
}
REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
REJCISHORT(CI_MRRU, neg_mrru, go->mrru);
REJCIVOID(CI_SSNHF, neg_ssnhf);
REJCIENDP(CI_EPDISC, neg_endpoint, go->endpoint.class,
go->endpoint.value, go->endpoint.length);
/*
* If there are any remaining CIs, then this packet is bad.
*/
if (len != 0)
goto bad;
/*
* Now we can update state.
*/
if (f->state != OPENED)
*go = try;
return 1;
bad:
LCPDEBUG(("lcp_rejci: received bad Reject!"));
return 0;
}
/*
* lcp_reqci - Check the peer's requested CIs and send appropriate response.
*
* Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
* appropriately. If reject_if_disagree is non-zero, doesn't return
* CONFNAK; returns CONFREJ if it can't return CONFACK.
*/
static int
lcp_reqci(fsm *f, u_char *inp, int *lenp, int reject_if_disagree)
{
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *ho = &lcp_hisoptions[f->unit];
lcp_options *ao = &lcp_allowoptions[f->unit];
u_char *cip, *next; /* Pointer to current and next CIs */
int cilen, citype, cichar; /* Parsed len, type, char value */
u_short cishort; /* Parsed short value */
u_int32_t cilong; /* Parse long value */
int rc = CONFACK; /* Final packet return code */
int orc; /* Individual option return code */
u_char *p; /* Pointer to next char to parse */
u_char *rejp; /* Pointer to next char in reject frame */
u_char *nakp; /* Pointer to next char in Nak frame */
int l = *lenp; /* Length left */
/*
* Reset all his options.
*/
BZERO(ho, sizeof(*ho));
/*
* Process all his options.
*/
next = inp;
nakp = nak_buffer;
rejp = inp;
while (l) {
orc = CONFACK; /* Assume success */
cip = p = next; /* Remember begining of CI */
if (l < 2 || /* Not enough data for CI header or */
p[1] < 2 || /* CI length too small or */
p[1] > l) { /* CI length too big? */
LCPDEBUG(("lcp_reqci: bad CI length!"));
orc = CONFREJ; /* Reject bad CI */
cilen = l; /* Reject till end of packet */
l = 0; /* Don't loop again */
citype = 0;
goto endswitch;
}
GETCHAR(citype, p); /* Parse CI type */
GETCHAR(cilen, p); /* Parse CI length */
l -= cilen; /* Adjust remaining length */
next += cilen; /* Step to next CI */
switch (citype) { /* Check CI type */
case CI_MRU:
if (!ao->neg_mru || /* Allow option? */
cilen != CILEN_SHORT) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
GETSHORT(cishort, p); /* Parse MRU */
/*
* He must be able to receive at least our minimum.
* No need to check a maximum. If he sends a large number,
* we'll just ignore it.
*/
if (cishort < MINMRU) {
orc = CONFNAK; /* Nak CI */
PUTCHAR(CI_MRU, nakp);
PUTCHAR(CILEN_SHORT, nakp);
PUTSHORT(MINMRU, nakp); /* Give him a hint */
break;
}
ho->neg_mru = 1; /* Remember he sent MRU */
ho->mru = cishort; /* And remember value */
break;
case CI_ASYNCMAP:
if (!ao->neg_asyncmap ||
cilen != CILEN_LONG) {
orc = CONFREJ;
break;
}
GETLONG(cilong, p);
/*
* Asyncmap must have set at least the bits
* which are set in lcp_allowoptions[unit].asyncmap.
*/
if ((ao->asyncmap & ~cilong) != 0) {
orc = CONFNAK;
PUTCHAR(CI_ASYNCMAP, nakp);
PUTCHAR(CILEN_LONG, nakp);
PUTLONG(ao->asyncmap | cilong, nakp);
break;
}
ho->neg_asyncmap = 1;
ho->asyncmap = cilong;
break;
case CI_AUTHTYPE:
if (cilen < CILEN_SHORT ||
!(ao->neg_upap || ao->neg_chap || ao->neg_eap)) {
/*
* Reject the option if we're not willing to authenticate.
*/
dbglog("No auth is possible");
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
/*
* Authtype must be PAP, CHAP, or EAP.
*
* Note: if more than one of ao->neg_upap, ao->neg_chap, and
* ao->neg_eap are set, and the peer sends a Configure-Request
* with two or more authenticate-protocol requests, then we will
* reject the second request.
* Whether we end up doing CHAP, UPAP, or EAP depends then on
* the ordering of the CIs in the peer's Configure-Request.
*/
if (cishort == PPP_PAP) {
/* we've already accepted CHAP or EAP */
if (ho->neg_chap || ho->neg_eap ||
cilen != CILEN_SHORT) {
LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
orc = CONFREJ;
break;
}
if (!ao->neg_upap) { /* we don't want to do PAP */
orc = CONFNAK; /* NAK it and suggest CHAP or EAP */
PUTCHAR(CI_AUTHTYPE, nakp);
if (ao->neg_eap) {
PUTCHAR(CILEN_SHORT, nakp);
PUTSHORT(PPP_EAP, nakp);
} else {
PUTCHAR(CILEN_CHAP, nakp);
PUTSHORT(PPP_CHAP, nakp);
PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
}
break;
}
ho->neg_upap = 1;
break;
}
if (cishort == PPP_CHAP) {
/* we've already accepted PAP or EAP */
if (ho->neg_upap || ho->neg_eap ||
cilen != CILEN_CHAP) {
LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
orc = CONFREJ;
break;
}
if (!ao->neg_chap) { /* we don't want to do CHAP */
orc = CONFNAK; /* NAK it and suggest EAP or PAP */
PUTCHAR(CI_AUTHTYPE, nakp);
PUTCHAR(CILEN_SHORT, nakp);
if (ao->neg_eap) {
PUTSHORT(PPP_EAP, nakp);
} else {
PUTSHORT(PPP_PAP, nakp);
}
break;
}
GETCHAR(cichar, p); /* get digest type */
if (!(CHAP_CANDIGEST(ao->chap_mdtype, cichar))) {
/*
* We can't/won't do the requested type,
* suggest something else.
*/
orc = CONFNAK;
PUTCHAR(CI_AUTHTYPE, nakp);
PUTCHAR(CILEN_CHAP, nakp);
PUTSHORT(PPP_CHAP, nakp);
PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
break;
}
ho->chap_mdtype = CHAP_MDTYPE_D(cichar); /* save md type */
ho->neg_chap = 1;
break;
}
if (cishort == PPP_EAP) {
/* we've already accepted CHAP or PAP */
if (ho->neg_chap || ho->neg_upap || cilen != CILEN_SHORT) {
LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE EAP, rejecting..."));
orc = CONFREJ;
break;
}
if (!ao->neg_eap) { /* we don't want to do EAP */
orc = CONFNAK; /* NAK it and suggest CHAP or PAP */
PUTCHAR(CI_AUTHTYPE, nakp);
if (ao->neg_chap) {
PUTCHAR(CILEN_CHAP, nakp);
PUTSHORT(PPP_CHAP, nakp);
PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
} else {
PUTCHAR(CILEN_SHORT, nakp);
PUTSHORT(PPP_PAP, nakp);
}
break;
}
ho->neg_eap = 1;
break;
}
/*
* We don't recognize the protocol they're asking for.
* Nak it with something we're willing to do.
* (At this point we know ao->neg_upap || ao->neg_chap ||
* ao->neg_eap.)
*/
orc = CONFNAK;
PUTCHAR(CI_AUTHTYPE, nakp);
if (ao->neg_eap) {
PUTCHAR(CILEN_SHORT, nakp);
PUTSHORT(PPP_EAP, nakp);
} else if (ao->neg_chap) {
PUTCHAR(CILEN_CHAP, nakp);
PUTSHORT(PPP_CHAP, nakp);
PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
} else {
PUTCHAR(CILEN_SHORT, nakp);
PUTSHORT(PPP_PAP, nakp);
}
break;
case CI_QUALITY:
if (!ao->neg_lqr ||
cilen != CILEN_LQR) {
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
GETLONG(cilong, p);
/*
* Check the protocol and the reporting period.
* XXX When should we Nak this, and what with?
*/
if (cishort != PPP_LQR) {
orc = CONFNAK;
PUTCHAR(CI_QUALITY, nakp);
PUTCHAR(CILEN_LQR, nakp);
PUTSHORT(PPP_LQR, nakp);
PUTLONG(ao->lqr_period, nakp);
break;
}
break;
case CI_MAGICNUMBER:
if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
cilen != CILEN_LONG) {
orc = CONFREJ;
break;
}
GETLONG(cilong, p);
/*
* He must have a different magic number.
*/
if (go->neg_magicnumber &&
cilong == go->magicnumber) {
cilong = magic(); /* Don't put magic() inside macro! */
orc = CONFNAK;
PUTCHAR(CI_MAGICNUMBER, nakp);
PUTCHAR(CILEN_LONG, nakp);
PUTLONG(cilong, nakp);
break;
}
ho->neg_magicnumber = 1;
ho->magicnumber = cilong;
break;
case CI_PCOMPRESSION:
if (!ao->neg_pcompression ||
cilen != CILEN_VOID) {
orc = CONFREJ;
break;
}
ho->neg_pcompression = 1;
break;
case CI_ACCOMPRESSION:
if (!ao->neg_accompression ||
cilen != CILEN_VOID) {
orc = CONFREJ;
break;
}
ho->neg_accompression = 1;
break;
case CI_MRRU:
if (!ao->neg_mrru || !multilink ||
cilen != CILEN_SHORT) {
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
/* possibly should insist on a minimum/maximum MRRU here */
ho->neg_mrru = 1;
ho->mrru = cishort;
break;
case CI_SSNHF:
if (!ao->neg_ssnhf || !multilink ||
cilen != CILEN_VOID) {
orc = CONFREJ;
break;
}
ho->neg_ssnhf = 1;
break;
case CI_EPDISC:
if (!ao->neg_endpoint ||
cilen < CILEN_CHAR ||
cilen > CILEN_CHAR + MAX_ENDP_LEN) {
orc = CONFREJ;
break;
}
GETCHAR(cichar, p);
cilen -= CILEN_CHAR;
ho->neg_endpoint = 1;
ho->endpoint.class = cichar;
ho->endpoint.length = cilen;
BCOPY(p, ho->endpoint.value, cilen);
INCPTR(cilen, p);
break;
default:
LCPDEBUG(("lcp_reqci: rcvd unknown option %d", citype));
orc = CONFREJ;
break;
}
endswitch:
if (orc == CONFACK && /* Good CI */
rc != CONFACK) /* but prior CI wasnt? */
continue; /* Don't send this one */
if (orc == CONFNAK) { /* Nak this CI? */
if (reject_if_disagree /* Getting fed up with sending NAKs? */
&& citype != CI_MAGICNUMBER) {
orc = CONFREJ; /* Get tough if so */
} else {
if (rc == CONFREJ) /* Rejecting prior CI? */
continue; /* Don't send this one */
rc = CONFNAK;
}
}
if (orc == CONFREJ) { /* Reject this CI */
rc = CONFREJ;
if (cip != rejp) /* Need to move rejected CI? */
BCOPY(cip, rejp, cilen); /* Move it */
INCPTR(cilen, rejp); /* Update output pointer */
}
}
/*
* If we wanted to send additional NAKs (for unsent CIs), the
* code would go here. The extra NAKs would go at *nakp.
* At present there are no cases where we want to ask the
* peer to negotiate an option.
*/
switch (rc) {
case CONFACK:
*lenp = next - inp;
break;
case CONFNAK:
/*
* Copy the Nak'd options from the nak_buffer to the caller's buffer.
*/
*lenp = nakp - nak_buffer;
BCOPY(nak_buffer, inp, *lenp);
break;
case CONFREJ:
*lenp = rejp - inp;
break;
}
LCPDEBUG(("lcp_reqci: returning CONF%s.", CODENAME(rc)));
return (rc); /* Return final code */
}
/*
* lcp_up - LCP has come UP.
*/
static void
lcp_up(fsm *f)
{
lcp_options *wo = &lcp_wantoptions[f->unit];
lcp_options *ho = &lcp_hisoptions[f->unit];
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *ao = &lcp_allowoptions[f->unit];
int mtu, mru;
if (!go->neg_magicnumber)
go->magicnumber = 0;
if (!ho->neg_magicnumber)
ho->magicnumber = 0;
/*
* Set our MTU to the smaller of the MTU we wanted and
* the MRU our peer wanted. If we negotiated an MRU,
* set our MRU to the larger of value we wanted and
* the value we got in the negotiation.
* Note on the MTU: the link MTU can be the MRU the peer wanted,
* the interface MTU is set to the lowest of that, the
* MTU we want to use, and our link MRU.
*/
mtu = ho->neg_mru? ho->mru: PPP_MRU;
mru = go->neg_mru? MAX(wo->mru, go->mru): PPP_MRU;
#ifdef PPP_WITH_MULTILINK
if (!(multilink && go->neg_mrru && ho->neg_mrru))
#endif /* PPP_WITH_MULTILINK */
ppp_set_mtu(f->unit, MIN(MIN(mtu, mru), ao->mru));
ppp_send_config(f->unit, mtu,
(ho->neg_asyncmap? ho->asyncmap: 0xffffffff),
ho->neg_pcompression, ho->neg_accompression);
ppp_recv_config(f->unit, mru,
(lax_recv? 0: go->neg_asyncmap? go->asyncmap: 0xffffffff),
go->neg_pcompression, go->neg_accompression);
if (ho->neg_mru)
peer_mru[f->unit] = ho->mru;
lcp_echo_lowerup(f->unit); /* Enable echo messages */
link_established(f->unit);
}
/*
* lcp_down - LCP has gone DOWN.
*
* Alert other protocols.
*/
static void
lcp_down(fsm *f)
{
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_echo_lowerdown(f->unit);
link_down(f->unit);
ppp_send_config(f->unit, PPP_MRU, 0xffffffff, 0, 0);
ppp_recv_config(f->unit, PPP_MRU,
(go->neg_asyncmap? go->asyncmap: 0xffffffff),
go->neg_pcompression, go->neg_accompression);
peer_mru[f->unit] = PPP_MRU;
}
/*
* lcp_starting - LCP needs the lower layer up.
*/
static void
lcp_starting(fsm *f)
{
link_required(f->unit);
}
/*
* lcp_finished - LCP has finished with the lower layer.
*/
static void
lcp_finished(fsm *f)
{
link_terminated(f->unit);
}
/*
* lcp_printpkt - print the contents of an LCP packet.
*/
static char *lcp_codenames[] = {
"ConfReq", "ConfAck", "ConfNak", "ConfRej",
"TermReq", "TermAck", "CodeRej", "ProtRej",
"EchoReq", "EchoRep", "DiscReq", "Ident",
"TimeRem"
};
static int
lcp_printpkt(u_char *p, int plen, void (*printer)(void *, char *, ...), void *arg)
{
int code, id, len, olen, i;
u_char *pstart, *optend;
u_short cishort;
u_int32_t cilong;
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(lcp_codenames) / sizeof(char *))
printer(arg, " %s", lcp_codenames[code-1]);
else
printer(arg, " code=0x%x", code);
printer(arg, " id=0x%x", id);
len -= HEADERLEN;
switch (code) {
case CONFREQ:
case CONFACK:
case CONFNAK:
case CONFREJ:
/* print option list */
while (len >= 2) {
GETCHAR(code, p);
GETCHAR(olen, p);
p -= 2;
if (olen < 2 || olen > len) {
break;
}
printer(arg, " <");
len -= olen;
optend = p + olen;
switch (code) {
case CI_MRU:
if (olen == CILEN_SHORT) {
p += 2;
GETSHORT(cishort, p);
printer(arg, "mru %d", cishort);
}
break;
case CI_ASYNCMAP:
if (olen == CILEN_LONG) {
p += 2;
GETLONG(cilong, p);
printer(arg, "asyncmap 0x%x", cilong);
}
break;
case CI_AUTHTYPE:
if (olen >= CILEN_SHORT) {
p += 2;
printer(arg, "auth ");
GETSHORT(cishort, p);
switch (cishort) {
case PPP_PAP:
printer(arg, "pap");
break;
case PPP_CHAP:
printer(arg, "chap");
if (p < optend) {
switch (*p) {
case CHAP_MD5:
printer(arg, " MD5");
++p;
break;
case CHAP_MICROSOFT:
printer(arg, " MS");
++p;
break;
case CHAP_MICROSOFT_V2:
printer(arg, " MS-v2");
++p;
break;
}
}
break;
case PPP_EAP:
printer(arg, "eap");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_QUALITY:
if (olen >= CILEN_SHORT) {
p += 2;
printer(arg, "quality ");
GETSHORT(cishort, p);
switch (cishort) {
case PPP_LQR:
printer(arg, "lqr");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_CALLBACK:
if (olen >= CILEN_CHAR) {
p += 2;
printer(arg, "callback ");
GETCHAR(cishort, p);
switch (cishort) {
case CBCP_OPT:
printer(arg, "CBCP");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_MAGICNUMBER:
if (olen == CILEN_LONG) {
p += 2;
GETLONG(cilong, p);
printer(arg, "magic 0x%x", cilong);
}
break;
case CI_PCOMPRESSION:
if (olen == CILEN_VOID) {
p += 2;
printer(arg, "pcomp");
}
break;
case CI_ACCOMPRESSION:
if (olen == CILEN_VOID) {
p += 2;
printer(arg, "accomp");
}
break;
case CI_MRRU:
if (olen == CILEN_SHORT) {
p += 2;
GETSHORT(cishort, p);
printer(arg, "mrru %d", cishort);
}
break;
case CI_SSNHF:
if (olen == CILEN_VOID) {
p += 2;
printer(arg, "ssnhf");
}
break;
case CI_EPDISC:
#ifdef PPP_WITH_MULTILINK
if (olen >= CILEN_CHAR) {
struct epdisc epd;
p += 2;
GETCHAR(epd.class, p);
epd.length = olen - CILEN_CHAR;
if (epd.length > MAX_ENDP_LEN)
epd.length = MAX_ENDP_LEN;
if (epd.length > 0) {
BCOPY(p, epd.value, epd.length);
p += epd.length;
}
printer(arg, "endpoint [%s]", epdisc_to_str(&epd));
}
#else
printer(arg, "endpoint");
#endif
break;
}
while (p < optend) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
printer(arg, ">");
}
break;
case TERMACK:
case TERMREQ:
if (len > 0 && *p >= ' ' && *p < 0x7f) {
printer(arg, " ");
print_string((char *)p, len, printer, arg);
p += len;
len = 0;
}
break;
case ECHOREQ:
case ECHOREP:
case DISCREQ:
if (len >= 4) {
GETLONG(cilong, p);
printer(arg, " magic=0x%x", cilong);
len -= 4;
}
break;
case IDENTIF:
case TIMEREM:
if (len >= 4) {
GETLONG(cilong, p);
printer(arg, " magic=0x%x", cilong);
len -= 4;
}
if (code == TIMEREM) {
if (len < 4)
break;
GETLONG(cilong, p);
printer(arg, " seconds=%u", cilong);
len -= 4;
}
if (len > 0) {
printer(arg, " ");
print_string((char *)p, len, printer, arg);
p += len;
len = 0;
}
break;
}
/* print the rest of the bytes in the packet */
for (i = 0; i < len && i < 32; ++i) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
if (i < len) {
printer(arg, " ...");
p += len - i;
}
return p - pstart;
}
/*
* Time to shut down the link because there is nothing out there.
*/
static
void LcpLinkFailure (fsm *f)
{
if (f->state == OPENED) {
info("No response to %d echo-requests", lcp_echos_pending);
notice("Serial link appears to be disconnected.");
ppp_set_status(EXIT_PEER_DEAD);
lcp_close(f->unit, "Peer not responding");
}
}
/*
* Timer expired for the LCP echo requests from this process.
*/
static void
LcpEchoCheck (fsm *f)
{
LcpSendEchoRequest (f);
if (f->state != OPENED)
return;
/*
* Start the timer for the next interval.
*/
if (lcp_echo_timer_running)
warn("assertion lcp_echo_timer_running==0 failed");
TIMEOUT (LcpEchoTimeout, f, lcp_echo_interval);
lcp_echo_timer_running = 1;
}
/*
* LcpEchoTimeout - Timer expired on the LCP echo
*/
static void
LcpEchoTimeout (void *arg)
{
if (lcp_echo_timer_running != 0) {
lcp_echo_timer_running = 0;
LcpEchoCheck ((fsm *) arg);
}
}
/*
* Log the round-trip time (RTT) of the received LCP echo-request.
*
* The header section at the beginning of lcp_rtt_file contains
* LCP_RTT_HEADER_LENGTH fields, each a u_int32_t in network byte order:
* [0] LCP_RTT_MAGIC
* [1] status (1: the file is open and is being written)
* [2] index of the most recently updated element
* [3] the value of the lcp-echo-interval parameter
*
* The header is followed by a ring buffer of LCP_RTT_ELEMENTS elements, each
* containing a pair of u_int32_t in network byte order with this content:
* [0] UNIX timestamp
* [1] bits 24-31: the number of lost LCP echo replies
* bits 0-23: the measured RTT in microseconds
*
* The timestamp is unsigned to support storing dates beyond 2038.
*
* Consumers of lcp_rtt_file are expected to:
* - read the complete file of arbitrary length
* - check the magic number
* - process the data elements starting at the index
* - ignore any elements with a timestamp of 0
*/
static void
lcp_rtt_update_buffer (unsigned long rtt)
{
volatile u_int32_t *const ring_header = lcp_rtt_buffer;
volatile u_int32_t *const ring_buffer = lcp_rtt_buffer
+ LCP_RTT_HEADER_LENGTH;
unsigned int next_entry, lost;
/* choose the next entry where the data will be stored */
if (ntohl(ring_header[2]) >= (LCP_RTT_ELEMENTS - 1) * 2)
next_entry = 0; /* go back to the beginning */
else
next_entry = ntohl(ring_header[2]) + 2; /* use the next one */
/* update the data element */
/* storing the timestamp in an *unsigned* long allows dates up to 2106 */
ring_buffer[next_entry] = htonl((u_int32_t) time(NULL));
lost = lcp_echos_pending - 1;
if (lost > 0xFF)
lost = 0xFF; /* truncate the lost packets count to 256 */
if (rtt > 0xFFFFFF)
rtt = 0xFFFFFF; /* truncate the RTT to 16777216 */
/* use bits 24-31 for the lost packets count and bits 0-23 for the RTT */
ring_buffer[next_entry + 1] = htonl((u_int32_t) ((lost << 24) + rtt));
/* update the pointer to the (just updated) most current data element */
ring_header[2] = htonl(next_entry);
/* In theory, CPUs implementing a weakly-consistent memory model do not
* guarantee that these three memory store operations to the buffer will
* be seen in the same order by the reader process.
* This means that a process reading the file could see the index
* having been updated before the element that the index points to had
* been written.
* But in practice we expect that the read(2) system call used by
* consumers processes is atomic with respect to the following msync(2)
* call, so we ignore the issue.
*/
if (msync(lcp_rtt_buffer, LCP_RTT_FILE_SIZE, MS_ASYNC) < 0)
error("msync() for %s failed: %m", lcp_rtt_file);
}
/*
* LcpEchoReply - LCP has received a reply to the echo
*/
static void
lcp_received_echo_reply (fsm *f, int id, u_char *inp, int len)
{
u_int32_t magic;
/* Check the magic number - don't count replies from ourselves. */
if (len < 4) {
dbglog("lcp: received short Echo-Reply, length %d", len);
return;
}
GETLONG(magic, inp);
if (lcp_gotoptions[f->unit].neg_magicnumber
&& magic == lcp_gotoptions[f->unit].magicnumber) {
warn("appear to have received our own echo-reply!");
return;
}
if (lcp_rtt_file_fd && len >= 16) {
long lcp_rtt_magic;
/*
* If the magic word is found at the beginning of the data section
* of the frame then read the timestamp which follows and subtract
* it from the current time to compute the round trip time.
*/
GETLONG(lcp_rtt_magic, inp);
if (lcp_rtt_magic == LCP_RTT_MAGIC) {
struct timespec ts;
unsigned long req_sec, req_nsec, rtt;
clock_gettime(CLOCK_MONOTONIC, &ts);
GETLONG(req_sec, inp);
GETLONG(req_nsec, inp);
/* compute the RTT in microseconds */
rtt = (ts.tv_sec - req_sec) * 1000000
+ (ts.tv_nsec / 1000 - req_nsec / 1000);
/* log the RTT */
lcp_rtt_update_buffer(rtt);
}
}
/* Reset the number of outstanding echo frames */
lcp_echos_pending = 0;
}
/*
* LcpSendEchoRequest - Send an echo request frame to the peer
*/
static void
LcpSendEchoRequest (fsm *f)
{
u_int32_t lcp_magic;
u_char pkt[16], *pktp;
/*
* Detect the failure of the peer at this point.
*/
if (lcp_echo_fails != 0) {
if (lcp_echos_pending >= lcp_echo_fails) {
LcpLinkFailure(f);
lcp_echos_pending = 0;
}
}
/*
* If adaptive echos have been enabled, only send the echo request if
* no traffic was received since the last one.
*/
if (lcp_echo_adaptive) {
static unsigned int last_pkts_in = 0;
struct pppd_stats cur_stats;
if (get_ppp_stats(f->unit, &cur_stats) && cur_stats.pkts_in != last_pkts_in) {
last_pkts_in = cur_stats.pkts_in;
/* receipt of traffic indicates the link is working... */
lcp_echos_pending = 0;
return;
}
}
/*
* Make and send the echo request frame.
*/
if (f->state == OPENED) {
lcp_magic = lcp_gotoptions[f->unit].magicnumber;
pktp = pkt;
PUTLONG(lcp_magic, pktp);
/* Put a timestamp in the data section of the frame */
if (lcp_rtt_file_fd) {
struct timespec ts;
PUTLONG(LCP_RTT_MAGIC, pktp);
clock_gettime(CLOCK_MONOTONIC, &ts);
PUTLONG((u_int32_t)ts.tv_sec, pktp);
PUTLONG((u_int32_t)ts.tv_nsec, pktp);
}
fsm_sdata(f, ECHOREQ, lcp_echo_number++ & 0xFF, pkt, pktp - pkt);
++lcp_echos_pending;
}
}
static void
lcp_rtt_open_file (void)
{
volatile u_int32_t *ring_header;
if (!lcp_rtt_file)
return;
lcp_rtt_file_fd = open(lcp_rtt_file, O_RDWR | O_CREAT, 0644);
if (lcp_rtt_file_fd < 0) {
error("Can't open the RTT log file %s: %m", lcp_rtt_file);
lcp_rtt_file_fd = 0;
return;
}
if (ftruncate(lcp_rtt_file_fd, LCP_RTT_FILE_SIZE) < 0)
fatal("ftruncate() of %s failed: %m", lcp_rtt_file);
lcp_rtt_buffer = mmap(0, LCP_RTT_FILE_SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED, lcp_rtt_file_fd, 0);
if (lcp_rtt_buffer == MAP_FAILED)
fatal("mmap() of %s failed: %m", lcp_rtt_file);
ring_header = lcp_rtt_buffer;
/* initialize the ring buffer */
if (ring_header[0] != htonl(LCP_RTT_MAGIC)) {
memset(lcp_rtt_buffer, 0, LCP_RTT_FILE_SIZE);
ring_header[0] = htonl(LCP_RTT_MAGIC);
}
ring_header[3] = htonl(lcp_echo_interval);
ring_header[1] = htonl(1); /* status: LCP up, file opened */
}
static void
lcp_rtt_close_file (void)
{
volatile u_int32_t *const ring_header = lcp_rtt_buffer;
if (!lcp_rtt_file_fd)
return;
ring_header[1] = htonl(0); /* status: LCP down, file closed */
if (munmap(lcp_rtt_buffer, LCP_RTT_FILE_SIZE) < 0)
error("munmap() of %s failed: %m", lcp_rtt_file);
if (close(lcp_rtt_file_fd) < 0)
error("close() of %s failed: %m", lcp_rtt_file);
lcp_rtt_buffer = NULL;
lcp_rtt_file_fd = 0;
}
/*
* lcp_echo_lowerup - Start the timer for the LCP frame
*/
static void
lcp_echo_lowerup (int unit)
{
fsm *f = &lcp_fsm[unit];
/* Clear the parameters for generating echo frames */
lcp_echos_pending = 0;
lcp_echo_number = 0;
lcp_echo_timer_running = 0;
/* Open the file where the LCP RTT data will be logged */
lcp_rtt_open_file();
/* If a timeout interval is specified then start the timer */
if (lcp_echo_interval != 0)
LcpEchoCheck (f);
}
/*
* lcp_echo_lowerdown - Stop the timer for the LCP frame
*/
static void
lcp_echo_lowerdown (int unit)
{
fsm *f = &lcp_fsm[unit];
if (lcp_echo_timer_running != 0) {
UNTIMEOUT (LcpEchoTimeout, f);
lcp_echo_timer_running = 0;
}
/* Close the file containing the LCP RTT data */
lcp_rtt_close_file();
}
