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freebsd-nq/usr.sbin/pppd/ipcp.c
Peter Wemm 97d92980a9 $Id$ -> $FreeBSD$
1999-08-28 01:35:59 +00:00

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/*
* ipcp.c - PPP IP Control Protocol.
*
* Copyright (c) 1989 Carnegie Mellon University.
* 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 Carnegie Mellon University. The name of the
* University 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[] = "$FreeBSD$";
#endif
/*
* TODO:
*/
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <netdb.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "pppd.h"
#include "fsm.h"
#include "ipcp.h"
#include "pathnames.h"
/* global vars */
ipcp_options ipcp_wantoptions[NUM_PPP]; /* Options that we want to request */
ipcp_options ipcp_gotoptions[NUM_PPP]; /* Options that peer ack'd */
ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
ipcp_options ipcp_hisoptions[NUM_PPP]; /* Options that we ack'd */
/* local vars */
static int cis_received[NUM_PPP]; /* # Conf-Reqs received */
static int default_route_set[NUM_PPP]; /* Have set up a default route */
static int proxy_arp_set[NUM_PPP]; /* Have created proxy arp entry */
/*
* Callbacks for fsm code. (CI = Configuration Information)
*/
static void ipcp_resetci __P((fsm *)); /* Reset our CI */
static int ipcp_cilen __P((fsm *)); /* Return length of our CI */
static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
static int ipcp_ackci __P((fsm *, u_char *, int)); /* Peer ack'd our CI */
static int ipcp_nakci __P((fsm *, u_char *, int)); /* Peer nak'd our CI */
static int ipcp_rejci __P((fsm *, u_char *, int)); /* Peer rej'd our CI */
static int ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
static void ipcp_up __P((fsm *)); /* We're UP */
static void ipcp_down __P((fsm *)); /* We're DOWN */
static void ipcp_script __P((fsm *, char *)); /* Run an up/down script */
static void ipcp_finished __P((fsm *)); /* Don't need lower layer */
fsm ipcp_fsm[NUM_PPP]; /* IPCP fsm structure */
static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
ipcp_resetci, /* Reset our Configuration Information */
ipcp_cilen, /* Length of our Configuration Information */
ipcp_addci, /* Add our Configuration Information */
ipcp_ackci, /* ACK our Configuration Information */
ipcp_nakci, /* NAK our Configuration Information */
ipcp_rejci, /* Reject our Configuration Information */
ipcp_reqci, /* Request peer's Configuration Information */
ipcp_up, /* Called when fsm reaches OPENED state */
ipcp_down, /* Called when fsm leaves OPENED state */
NULL, /* Called when we want the lower layer up */
ipcp_finished, /* Called when we want the lower layer down */
NULL, /* Called when Protocol-Reject received */
NULL, /* Retransmission is necessary */
NULL, /* Called to handle protocol-specific codes */
"IPCP" /* String name of protocol */
};
/*
* Protocol entry points from main code.
*/
static void ipcp_init __P((int));
static void ipcp_open __P((int));
static void ipcp_close __P((int, char *));
static void ipcp_lowerup __P((int));
static void ipcp_lowerdown __P((int));
static void ipcp_input __P((int, u_char *, int));
static void ipcp_protrej __P((int));
static int ipcp_printpkt __P((u_char *, int,
void (*) __P((void *, char *, ...)), void *));
static void ip_check_options __P((void));
static int ip_demand_conf __P((int));
static int ip_active_pkt __P((u_char *, int));
struct protent ipcp_protent = {
PPP_IPCP,
ipcp_init,
ipcp_input,
ipcp_protrej,
ipcp_lowerup,
ipcp_lowerdown,
ipcp_open,
ipcp_close,
ipcp_printpkt,
NULL,
1,
"IPCP",
ip_check_options,
ip_demand_conf,
ip_active_pkt
};
static void ipcp_clear_addrs __P((int));
/*
* Lengths of configuration options.
*/
#define CILEN_VOID 2
#define CILEN_COMPRESS 4 /* min length for compression protocol opt. */
#define CILEN_VJ 6 /* length for RFC1332 Van-Jacobson opt. */
#define CILEN_ADDR 6 /* new-style single address option */
#define CILEN_ADDRS 10 /* old-style dual address option */
#define CODENAME(x) ((x) == CONFACK ? "ACK" : \
(x) == CONFNAK ? "NAK" : "REJ")
/*
* Make a string representation of a network IP address.
*/
char *
ip_ntoa(ipaddr)
u_int32_t ipaddr;
{
static char b[64];
ipaddr = ntohl(ipaddr);
sprintf(b, "%d.%d.%d.%d",
(u_char)(ipaddr >> 24),
(u_char)(ipaddr >> 16),
(u_char)(ipaddr >> 8),
(u_char)(ipaddr));
return b;
}
/*
* ipcp_init - Initialize IPCP.
*/
static void
ipcp_init(unit)
int unit;
{
fsm *f = &ipcp_fsm[unit];
ipcp_options *wo = &ipcp_wantoptions[unit];
ipcp_options *ao = &ipcp_allowoptions[unit];
f->unit = unit;
f->protocol = PPP_IPCP;
f->callbacks = &ipcp_callbacks;
fsm_init(&ipcp_fsm[unit]);
memset(wo, 0, sizeof(*wo));
memset(ao, 0, sizeof(*ao));
wo->neg_addr = 1;
wo->neg_vj = 1;
wo->vj_protocol = IPCP_VJ_COMP;
wo->maxslotindex = MAX_STATES - 1; /* really max index */
wo->cflag = 1;
/* max slots and slot-id compression are currently hardwired in */
/* ppp_if.c to 16 and 1, this needs to be changed (among other */
/* things) gmc */
ao->neg_addr = 1;
ao->neg_vj = 1;
ao->maxslotindex = MAX_STATES - 1;
ao->cflag = 1;
/*
* XXX These control whether the user may use the proxyarp
* and defaultroute options.
*/
ao->proxy_arp = 1;
ao->default_route = 1;
}
/*
* ipcp_open - IPCP is allowed to come up.
*/
static void
ipcp_open(unit)
int unit;
{
fsm_open(&ipcp_fsm[unit]);
}
/*
* ipcp_close - Take IPCP down.
*/
static void
ipcp_close(unit, reason)
int unit;
char *reason;
{
fsm_close(&ipcp_fsm[unit], reason);
}
/*
* ipcp_lowerup - The lower layer is up.
*/
static void
ipcp_lowerup(unit)
int unit;
{
fsm_lowerup(&ipcp_fsm[unit]);
}
/*
* ipcp_lowerdown - The lower layer is down.
*/
static void
ipcp_lowerdown(unit)
int unit;
{
fsm_lowerdown(&ipcp_fsm[unit]);
}
/*
* ipcp_input - Input IPCP packet.
*/
static void
ipcp_input(unit, p, len)
int unit;
u_char *p;
int len;
{
fsm_input(&ipcp_fsm[unit], p, len);
}
/*
* ipcp_protrej - A Protocol-Reject was received for IPCP.
*
* Pretend the lower layer went down, so we shut up.
*/
static void
ipcp_protrej(unit)
int unit;
{
fsm_lowerdown(&ipcp_fsm[unit]);
}
/*
* ipcp_resetci - Reset our CI.
*/
static void
ipcp_resetci(f)
fsm *f;
{
ipcp_options *wo = &ipcp_wantoptions[f->unit];
wo->req_addr = wo->neg_addr && ipcp_allowoptions[f->unit].neg_addr;
if (wo->ouraddr == 0)
wo->accept_local = 1;
if (wo->hisaddr == 0)
wo->accept_remote = 1;
ipcp_gotoptions[f->unit] = *wo;
cis_received[f->unit] = 0;
}
/*
* ipcp_cilen - Return length of our CI.
*/
static int
ipcp_cilen(f)
fsm *f;
{
ipcp_options *go = &ipcp_gotoptions[f->unit];
ipcp_options *wo = &ipcp_wantoptions[f->unit];
ipcp_options *ho = &ipcp_hisoptions[f->unit];
#define LENCIVJ(neg, old) (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
#define LENCIADDR(neg, old) (neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0)
/*
* First see if we want to change our options to the old
* forms because we have received old forms from the peer.
*/
if (wo->neg_addr && !go->neg_addr && !go->old_addrs) {
/* use the old style of address negotiation */
go->neg_addr = 1;
go->old_addrs = 1;
}
if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
/* try an older style of VJ negotiation */
if (cis_received[f->unit] == 0) {
/* keep trying the new style until we see some CI from the peer */
go->neg_vj = 1;
} else {
/* use the old style only if the peer did */
if (ho->neg_vj && ho->old_vj) {
go->neg_vj = 1;
go->old_vj = 1;
go->vj_protocol = ho->vj_protocol;
}
}
}
return (LENCIADDR(go->neg_addr, go->old_addrs) +
LENCIVJ(go->neg_vj, go->old_vj));
}
/*
* ipcp_addci - Add our desired CIs to a packet.
*/
static void
ipcp_addci(f, ucp, lenp)
fsm *f;
u_char *ucp;
int *lenp;
{
ipcp_options *go = &ipcp_gotoptions[f->unit];
int len = *lenp;
#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
if (neg) { \
int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
if (len >= vjlen) { \
PUTCHAR(opt, ucp); \
PUTCHAR(vjlen, ucp); \
PUTSHORT(val, ucp); \
if (!old) { \
PUTCHAR(maxslotindex, ucp); \
PUTCHAR(cflag, ucp); \
} \
len -= vjlen; \
} else \
neg = 0; \
}
#define ADDCIADDR(opt, neg, old, val1, val2) \
if (neg) { \
int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
if (len >= addrlen) { \
u_int32_t l; \
PUTCHAR(opt, ucp); \
PUTCHAR(addrlen, ucp); \
l = ntohl(val1); \
PUTLONG(l, ucp); \
if (old) { \
l = ntohl(val2); \
PUTLONG(l, ucp); \
} \
len -= addrlen; \
} else \
neg = 0; \
}
ADDCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
go->old_addrs, go->ouraddr, go->hisaddr);
ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
go->maxslotindex, go->cflag);
*lenp -= len;
}
/*
* ipcp_ackci - Ack our CIs.
*
* Returns:
* 0 - Ack was bad.
* 1 - Ack was good.
*/
static int
ipcp_ackci(f, p, len)
fsm *f;
u_char *p;
int len;
{
ipcp_options *go = &ipcp_gotoptions[f->unit];
u_short cilen, citype, cishort;
u_int32_t cilong;
u_char cimaxslotindex, cicflag;
/*
* 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 ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
if (neg) { \
int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
if ((len -= vjlen) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != vjlen || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != val) \
goto bad; \
if (!old) { \
GETCHAR(cimaxslotindex, p); \
if (cimaxslotindex != maxslotindex) \
goto bad; \
GETCHAR(cicflag, p); \
if (cicflag != cflag) \
goto bad; \
} \
}
#define ACKCIADDR(opt, neg, old, val1, val2) \
if (neg) { \
int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
u_int32_t l; \
if ((len -= addrlen) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != addrlen || \
citype != opt) \
goto bad; \
GETLONG(l, p); \
cilong = htonl(l); \
if (val1 != cilong) \
goto bad; \
if (old) { \
GETLONG(l, p); \
cilong = htonl(l); \
if (val2 != cilong) \
goto bad; \
} \
}
ACKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
go->old_addrs, go->ouraddr, go->hisaddr);
ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
go->maxslotindex, go->cflag);
/*
* If there are any remaining CIs, then this packet is bad.
*/
if (len != 0)
goto bad;
return (1);
bad:
IPCPDEBUG((LOG_INFO, "ipcp_ackci: received bad Ack!"));
return (0);
}
/*
* ipcp_nakci - Peer has sent a NAK for some of our CIs.
* This should not modify any state if the Nak is bad
* or if IPCP is in the OPENED state.
*
* Returns:
* 0 - Nak was bad.
* 1 - Nak was good.
*/
static int
ipcp_nakci(f, p, len)
fsm *f;
u_char *p;
int len;
{
ipcp_options *go = &ipcp_gotoptions[f->unit];
u_char cimaxslotindex, cicflag;
u_char citype, cilen, *next;
u_short cishort;
u_int32_t ciaddr1, ciaddr2, l;
ipcp_options no; /* options we've seen Naks for */
ipcp_options try; /* options to request next time */
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 NAKCIADDR(opt, neg, old, code) \
if (go->neg && \
len >= (cilen = (old? CILEN_ADDRS: CILEN_ADDR)) && \
p[1] == cilen && \
p[0] == opt) { \
len -= cilen; \
INCPTR(2, p); \
GETLONG(l, p); \
ciaddr1 = htonl(l); \
if (old) { \
GETLONG(l, p); \
ciaddr2 = htonl(l); \
no.old_addrs = 1; \
} else \
ciaddr2 = 0; \
no.neg = 1; \
code \
}
#define NAKCIVJ(opt, neg, code) \
if (go->neg && \
((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
len >= cilen && \
p[0] == opt) { \
len -= cilen; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
no.neg = 1; \
code \
}
/*
* Accept the peer's idea of {our,his} address, if different
* from our idea, only if the accept_{local,remote} flag is set.
*/
NAKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr, go->old_addrs,
if (go->accept_local && ciaddr1) { /* Do we know our address? */
try.ouraddr = ciaddr1;
IPCPDEBUG((LOG_INFO, "local IP address %s",
ip_ntoa(ciaddr1)));
}
if (go->accept_remote && ciaddr2) { /* Does he know his? */
try.hisaddr = ciaddr2;
IPCPDEBUG((LOG_INFO, "remote IP address %s",
ip_ntoa(ciaddr2)));
}
);
/*
* Accept the peer's value of maxslotindex provided that it
* is less than what we asked for. Turn off slot-ID compression
* if the peer wants. Send old-style compress-type option if
* the peer wants.
*/
NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
if (cilen == CILEN_VJ) {
GETCHAR(cimaxslotindex, p);
GETCHAR(cicflag, p);
if (cishort == IPCP_VJ_COMP) {
try.old_vj = 0;
if (cimaxslotindex < go->maxslotindex)
try.maxslotindex = cimaxslotindex;
if (!cicflag)
try.cflag = 0;
} else {
try.neg_vj = 0;
}
} else {
if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
try.old_vj = 1;
try.vj_protocol = cishort;
} else {
try.neg_vj = 0;
}
}
);
/*
* There may be remaining CIs, if the peer is requesting negotiation
* on an option that we didn't include in our request packet.
* If they want to negotiate about IP addresses, we comply.
* If they want us to ask for compression, we refuse.
*/
while (len > CILEN_VOID) {
GETCHAR(citype, p);
GETCHAR(cilen, p);
if( (len -= cilen) < 0 )
goto bad;
next = p + cilen - 2;
switch (citype) {
case CI_COMPRESSTYPE:
if (go->neg_vj || no.neg_vj ||
(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
goto bad;
no.neg_vj = 1;
break;
case CI_ADDRS:
if ((go->neg_addr && go->old_addrs) || no.old_addrs
|| cilen != CILEN_ADDRS)
goto bad;
try.neg_addr = 1;
try.old_addrs = 1;
GETLONG(l, p);
ciaddr1 = htonl(l);
if (ciaddr1 && go->accept_local)
try.ouraddr = ciaddr1;
GETLONG(l, p);
ciaddr2 = htonl(l);
if (ciaddr2 && go->accept_remote)
try.hisaddr = ciaddr2;
no.old_addrs = 1;
break;
case CI_ADDR:
if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
goto bad;
try.old_addrs = 0;
GETLONG(l, p);
ciaddr1 = htonl(l);
if (ciaddr1 && go->accept_local)
try.ouraddr = ciaddr1;
if (try.ouraddr != 0)
try.neg_addr = 1;
no.neg_addr = 1;
break;
}
p = next;
}
/* If there is still anything left, this packet is bad. */
if (len != 0)
goto bad;
/*
* OK, the Nak is good. Now we can update state.
*/
if (f->state != OPENED)
*go = try;
return 1;
bad:
IPCPDEBUG((LOG_INFO, "ipcp_nakci: received bad Nak!"));
return 0;
}
/*
* ipcp_rejci - Reject some of our CIs.
*/
static int
ipcp_rejci(f, p, len)
fsm *f;
u_char *p;
int len;
{
ipcp_options *go = &ipcp_gotoptions[f->unit];
u_char cimaxslotindex, ciflag, cilen;
u_short cishort;
u_int32_t cilong;
ipcp_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 REJCIADDR(opt, neg, old, val1, val2) \
if (go->neg && \
len >= (cilen = old? CILEN_ADDRS: CILEN_ADDR) && \
p[1] == cilen && \
p[0] == opt) { \
u_int32_t l; \
len -= cilen; \
INCPTR(2, p); \
GETLONG(l, p); \
cilong = htonl(l); \
/* Check rejected value. */ \
if (cilong != val1) \
goto bad; \
if (old) { \
GETLONG(l, p); \
cilong = htonl(l); \
/* Check rejected value. */ \
if (cilong != val2) \
goto bad; \
} \
try.neg = 0; \
}
#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
if (go->neg && \
p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
len >= p[1] && \
p[0] == opt) { \
len -= p[1]; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
/* Check rejected value. */ \
if (cishort != val) \
goto bad; \
if (!old) { \
GETCHAR(cimaxslotindex, p); \
if (cimaxslotindex != maxslot) \
goto bad; \
GETCHAR(ciflag, p); \
if (ciflag != cflag) \
goto bad; \
} \
try.neg = 0; \
}
REJCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr,
go->old_addrs, go->ouraddr, go->hisaddr);
REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
go->maxslotindex, go->cflag);
/*
* 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:
IPCPDEBUG((LOG_INFO, "ipcp_rejci: received bad Reject!"));
return 0;
}
/*
* ipcp_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
ipcp_reqci(f, inp, len, reject_if_disagree)
fsm *f;
u_char *inp; /* Requested CIs */
int *len; /* Length of requested CIs */
int reject_if_disagree;
{
ipcp_options *wo = &ipcp_wantoptions[f->unit];
ipcp_options *ho = &ipcp_hisoptions[f->unit];
ipcp_options *ao = &ipcp_allowoptions[f->unit];
ipcp_options *go = &ipcp_gotoptions[f->unit];
u_char *cip, *next; /* Pointer to current and next CIs */
u_short cilen, citype; /* Parsed len, type */
u_short cishort; /* Parsed short value */
u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
int rc = CONFACK; /* Final packet return code */
int orc; /* Individual option return code */
u_char *p; /* Pointer to next char to parse */
u_char *ucp = inp; /* Pointer to current output char */
int l = *len; /* Length left */
u_char maxslotindex, cflag;
int d;
cis_received[f->unit] = 1;
/*
* Reset all his options.
*/
BZERO(ho, sizeof(*ho));
/*
* Process all his options.
*/
next = 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? */
IPCPDEBUG((LOG_INFO, "ipcp_reqci: bad CI length!"));
orc = CONFREJ; /* Reject bad CI */
cilen = l; /* Reject till end of packet */
l = 0; /* Don't loop again */
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_ADDRS:
IPCPDEBUG((LOG_INFO, "ipcp: received ADDRS "));
if (!ao->neg_addr ||
cilen != CILEN_ADDRS) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
/*
* If he has no address, or if we both have his address but
* disagree about it, then NAK it with our idea.
* In particular, if we don't know his address, but he does,
* then accept it.
*/
GETLONG(tl, p); /* Parse source address (his) */
ciaddr1 = htonl(tl);
IPCPDEBUG((LOG_INFO, "(%s:", ip_ntoa(ciaddr1)));
if (ciaddr1 != wo->hisaddr
&& (ciaddr1 == 0 || !wo->accept_remote)) {
orc = CONFNAK;
if (!reject_if_disagree) {
DECPTR(sizeof(u_int32_t), p);
tl = ntohl(wo->hisaddr);
PUTLONG(tl, p);
}
} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
/*
* If neither we nor he knows his address, reject the option.
*/
orc = CONFREJ;
wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
break;
}
/*
* If he doesn't know our address, or if we both have our address
* but disagree about it, then NAK it with our idea.
*/
GETLONG(tl, p); /* Parse desination address (ours) */
ciaddr2 = htonl(tl);
IPCPDEBUG((LOG_INFO, "%s)", ip_ntoa(ciaddr2)));
if (ciaddr2 != wo->ouraddr) {
if (ciaddr2 == 0 || !wo->accept_local) {
orc = CONFNAK;
if (!reject_if_disagree) {
DECPTR(sizeof(u_int32_t), p);
tl = ntohl(wo->ouraddr);
PUTLONG(tl, p);
}
} else {
go->ouraddr = ciaddr2; /* accept peer's idea */
}
}
ho->neg_addr = 1;
ho->old_addrs = 1;
ho->hisaddr = ciaddr1;
ho->ouraddr = ciaddr2;
break;
case CI_ADDR:
IPCPDEBUG((LOG_INFO, "ipcp: received ADDR "));
if (!ao->neg_addr ||
cilen != CILEN_ADDR) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
/*
* If he has no address, or if we both have his address but
* disagree about it, then NAK it with our idea.
* In particular, if we don't know his address, but he does,
* then accept it.
*/
GETLONG(tl, p); /* Parse source address (his) */
ciaddr1 = htonl(tl);
IPCPDEBUG((LOG_INFO, "(%s)", ip_ntoa(ciaddr1)));
if (ciaddr1 != wo->hisaddr
&& (ciaddr1 == 0 || !wo->accept_remote)) {
orc = CONFNAK;
if (!reject_if_disagree) {
DECPTR(sizeof(u_int32_t), p);
tl = ntohl(wo->hisaddr);
PUTLONG(tl, p);
}
} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
/*
* Don't ACK an address of 0.0.0.0 - reject it instead.
*/
orc = CONFREJ;
wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
break;
}
ho->neg_addr = 1;
ho->hisaddr = ciaddr1;
break;
case CI_MS_DNS1:
case CI_MS_DNS2:
/* Microsoft primary or secondary DNS request */
d = citype == CI_MS_DNS2;
IPCPDEBUG((LOG_INFO, "ipcp: received DNS%d Request ", d+1));
/* If we do not have a DNS address then we cannot send it */
if (ao->dnsaddr[d] == 0 ||
cilen != CILEN_ADDR) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
GETLONG(tl, p);
if (htonl(tl) != ao->dnsaddr[d]) {
DECPTR(sizeof(u_int32_t), p);
tl = ntohl(ao->dnsaddr[d]);
PUTLONG(tl, p);
orc = CONFNAK;
}
break;
case CI_MS_WINS1:
case CI_MS_WINS2:
/* Microsoft primary or secondary WINS request */
d = citype == CI_MS_WINS2;
IPCPDEBUG((LOG_INFO, "ipcp: received WINS%d Request ", d+1));
/* If we do not have a DNS address then we cannot send it */
if (ao->winsaddr[d] == 0 ||
cilen != CILEN_ADDR) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
GETLONG(tl, p);
if (htonl(tl) != ao->winsaddr[d]) {
DECPTR(sizeof(u_int32_t), p);
tl = ntohl(ao->winsaddr[d]);
PUTLONG(tl, p);
orc = CONFNAK;
}
break;
case CI_COMPRESSTYPE:
IPCPDEBUG((LOG_INFO, "ipcp: received COMPRESSTYPE "));
if (!ao->neg_vj ||
(cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
IPCPDEBUG((LOG_INFO, "(%d)", cishort));
if (!(cishort == IPCP_VJ_COMP ||
(cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
orc = CONFREJ;
break;
}
ho->neg_vj = 1;
ho->vj_protocol = cishort;
if (cilen == CILEN_VJ) {
GETCHAR(maxslotindex, p);
if (maxslotindex > ao->maxslotindex) {
orc = CONFNAK;
if (!reject_if_disagree){
DECPTR(1, p);
PUTCHAR(ao->maxslotindex, p);
}
}
GETCHAR(cflag, p);
if (cflag && !ao->cflag) {
orc = CONFNAK;
if (!reject_if_disagree){
DECPTR(1, p);
PUTCHAR(wo->cflag, p);
}
}
ho->maxslotindex = maxslotindex;
ho->cflag = cflag;
} else {
ho->old_vj = 1;
ho->maxslotindex = MAX_STATES - 1;
ho->cflag = 1;
}
break;
default:
orc = CONFREJ;
break;
}
endswitch:
IPCPDEBUG((LOG_INFO, " (%s)\n", CODENAME(orc)));
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? */
orc = CONFREJ; /* Get tough if so */
else {
if (rc == CONFREJ) /* Rejecting prior CI? */
continue; /* Don't send this one */
if (rc == CONFACK) { /* Ack'd all prior CIs? */
rc = CONFNAK; /* Not anymore... */
ucp = inp; /* Backup */
}
}
}
if (orc == CONFREJ && /* Reject this CI */
rc != CONFREJ) { /* but no prior ones? */
rc = CONFREJ;
ucp = inp; /* Backup */
}
/* Need to move CI? */
if (ucp != cip)
BCOPY(cip, ucp, cilen); /* Move it */
/* Update output pointer */
INCPTR(cilen, ucp);
}
/*
* If we aren't rejecting this packet, and we want to negotiate
* their address, and they didn't send their address, then we
* send a NAK with a CI_ADDR option appended. We assume the
* input buffer is long enough that we can append the extra
* option safely.
*/
if (rc != CONFREJ && !ho->neg_addr &&
wo->req_addr && !reject_if_disagree) {
if (rc == CONFACK) {
rc = CONFNAK;
ucp = inp; /* reset pointer */
wo->req_addr = 0; /* don't ask again */
}
PUTCHAR(CI_ADDR, ucp);
PUTCHAR(CILEN_ADDR, ucp);
tl = ntohl(wo->hisaddr);
PUTLONG(tl, ucp);
}
*len = ucp - inp; /* Compute output length */
IPCPDEBUG((LOG_INFO, "ipcp: returning Configure-%s", CODENAME(rc)));
return (rc); /* Return final code */
}
/*
* ip_check_options - check that any IP-related options are OK,
* and assign appropriate defaults.
*/
static void
ip_check_options()
{
struct hostent *hp;
u_int32_t local;
ipcp_options *wo = &ipcp_wantoptions[0];
/*
* Default our local IP address based on our hostname.
* If local IP address already given, don't bother.
*/
if (wo->ouraddr == 0 && !disable_defaultip) {
/*
* Look up our hostname (possibly with domain name appended)
* and take the first IP address as our local IP address.
* If there isn't an IP address for our hostname, too bad.
*/
wo->accept_local = 1; /* don't insist on this default value */
if ((hp = gethostbyname(hostname)) != NULL) {
local = *(u_int32_t *)hp->h_addr;
if (local != 0 && !bad_ip_adrs(local))
wo->ouraddr = local;
}
}
if (demand && wo->hisaddr == 0) {
option_error("remote IP address required for demand-dialling\n");
exit(1);
}
#if 0
if (demand && wo->accept_remote) {
option_error("ipcp-accept-remote is incompatible with demand\n");
exit(1);
}
#endif
}
/*
* ip_demand_conf - configure the interface as though
* IPCP were up, for use with dial-on-demand.
*/
static int
ip_demand_conf(u)
int u;
{
ipcp_options *wo = &ipcp_wantoptions[u];
if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
return 0;
if (!sifup(u))
return 0;
if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
return 0;
if (wo->default_route)
if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr))
default_route_set[u] = 1;
if (wo->proxy_arp)
if (sifproxyarp(u, wo->hisaddr))
proxy_arp_set[u] = 1;
syslog(LOG_NOTICE, "local IP address %s", ip_ntoa(wo->ouraddr));
syslog(LOG_NOTICE, "remote IP address %s", ip_ntoa(wo->hisaddr));
return 1;
}
/*
* ipcp_up - IPCP has come UP.
*
* Configure the IP network interface appropriately and bring it up.
*/
static void
ipcp_up(f)
fsm *f;
{
u_int32_t mask;
ipcp_options *ho = &ipcp_hisoptions[f->unit];
ipcp_options *go = &ipcp_gotoptions[f->unit];
ipcp_options *wo = &ipcp_wantoptions[f->unit];
np_up(f->unit, PPP_IP);
IPCPDEBUG((LOG_INFO, "ipcp: up"));
/*
* We must have a non-zero IP address for both ends of the link.
*/
if (!ho->neg_addr)
ho->hisaddr = wo->hisaddr;
if (ho->hisaddr == 0) {
syslog(LOG_ERR, "Could not determine remote IP address");
ipcp_close(f->unit, "Could not determine remote IP address");
return;
}
if (go->ouraddr == 0) {
syslog(LOG_ERR, "Could not determine local IP address");
ipcp_close(f->unit, "Could not determine local IP address");
return;
}
script_setenv("IPLOCAL", ip_ntoa(go->ouraddr));
script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr));
/*
* Check that the peer is allowed to use the IP address it wants.
*/
if (!auth_ip_addr(f->unit, ho->hisaddr)) {
syslog(LOG_ERR, "Peer is not authorized to use remote address %s",
ip_ntoa(ho->hisaddr));
ipcp_close(f->unit, "Unauthorized remote IP address");
return;
}
/* set tcp compression */
sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
/*
* If we are doing dial-on-demand, the interface is already
* configured, so we put out any saved-up packets, then set the
* interface to pass IP packets.
*/
if (demand) {
if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
if (go->ouraddr != wo->ouraddr)
syslog(LOG_WARNING, "Local IP address changed to %s",
ip_ntoa(go->ouraddr));
if (ho->hisaddr != wo->hisaddr)
syslog(LOG_WARNING, "Remote IP address changed to %s",
ip_ntoa(ho->hisaddr));
ipcp_clear_addrs(f->unit);
/* Set the interface to the new addresses */
mask = GetMask(go->ouraddr);
if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
IPCPDEBUG((LOG_WARNING, "sifaddr failed"));
ipcp_close(f->unit, "Interface configuration failed");
return;
}
/* assign a default route through the interface if required */
if (ipcp_wantoptions[f->unit].default_route)
if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
default_route_set[f->unit] = 1;
/* Make a proxy ARP entry if requested. */
if (ipcp_wantoptions[f->unit].proxy_arp)
if (sifproxyarp(f->unit, ho->hisaddr))
proxy_arp_set[f->unit] = 1;
}
demand_rexmit(PPP_IP);
sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
} else {
/*
* Set IP addresses and (if specified) netmask.
*/
mask = GetMask(go->ouraddr);
#if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))
if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
IPCPDEBUG((LOG_WARNING, "sifaddr failed"));
ipcp_close(f->unit, "Interface configuration failed");
return;
}
#endif
/* bring the interface up for IP */
if (!sifup(f->unit)) {
IPCPDEBUG((LOG_WARNING, "sifup failed"));
ipcp_close(f->unit, "Interface configuration failed");
return;
}
#if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))
if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
IPCPDEBUG((LOG_WARNING, "sifaddr failed"));
ipcp_close(f->unit, "Interface configuration failed");
return;
}
#endif
sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
/* assign a default route through the interface if required */
if (ipcp_wantoptions[f->unit].default_route)
if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
default_route_set[f->unit] = 1;
/* Make a proxy ARP entry if requested. */
if (ipcp_wantoptions[f->unit].proxy_arp)
if (sifproxyarp(f->unit, ho->hisaddr))
proxy_arp_set[f->unit] = 1;
syslog(LOG_NOTICE, "local IP address %s", ip_ntoa(go->ouraddr));
syslog(LOG_NOTICE, "remote IP address %s", ip_ntoa(ho->hisaddr));
}
/*
* Execute the ip-up script, like this:
* /etc/ppp/ip-up interface tty speed local-IP remote-IP
*/
ipcp_script(f, _PATH_IPUP);
}
/*
* ipcp_down - IPCP has gone DOWN.
*
* Take the IP network interface down, clear its addresses
* and delete routes through it.
*/
static void
ipcp_down(f)
fsm *f;
{
IPCPDEBUG((LOG_INFO, "ipcp: down"));
np_down(f->unit, PPP_IP);
sifvjcomp(f->unit, 0, 0, 0);
/*
* If we are doing dial-on-demand, set the interface
* to queue up outgoing packets (for now).
*/
if (demand) {
sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE);
} else {
sifdown(f->unit);
ipcp_clear_addrs(f->unit);
}
/* Execute the ip-down script */
ipcp_script(f, _PATH_IPDOWN);
}
/*
* ipcp_clear_addrs() - clear the interface addresses, routes,
* proxy arp entries, etc.
*/
static void
ipcp_clear_addrs(unit)
int unit;
{
u_int32_t ouraddr, hisaddr;
ouraddr = ipcp_gotoptions[unit].ouraddr;
hisaddr = ipcp_hisoptions[unit].hisaddr;
if (proxy_arp_set[unit]) {
cifproxyarp(unit, hisaddr);
proxy_arp_set[unit] = 0;
}
if (default_route_set[unit]) {
cifdefaultroute(unit, ouraddr, hisaddr);
default_route_set[unit] = 0;
}
cifaddr(unit, ouraddr, hisaddr);
}
/*
* ipcp_finished - possibly shut down the lower layers.
*/
static void
ipcp_finished(f)
fsm *f;
{
np_finished(f->unit, PPP_IP);
}
/*
* ipcp_script - Execute a script with arguments
* interface-name tty-name speed local-IP remote-IP.
*/
static void
ipcp_script(f, script)
fsm *f;
char *script;
{
char strspeed[32], strlocal[32], strremote[32];
char *argv[8];
sprintf(strspeed, "%d", baud_rate);
strcpy(strlocal, ip_ntoa(ipcp_gotoptions[f->unit].ouraddr));
strcpy(strremote, ip_ntoa(ipcp_hisoptions[f->unit].hisaddr));
argv[0] = script;
argv[1] = ifname;
argv[2] = devnam;
argv[3] = strspeed;
argv[4] = strlocal;
argv[5] = strremote;
argv[6] = ipparam;
argv[7] = NULL;
run_program(script, argv, 0);
}
/*
* ipcp_printpkt - print the contents of an IPCP packet.
*/
static char *ipcp_codenames[] = {
"ConfReq", "ConfAck", "ConfNak", "ConfRej",
"TermReq", "TermAck", "CodeRej"
};
static int
ipcp_printpkt(p, plen, printer, arg)
u_char *p;
int plen;
void (*printer) __P((void *, char *, ...));
void *arg;
{
int code, id, len, olen;
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(ipcp_codenames) / sizeof(char *))
printer(arg, " %s", ipcp_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_ADDRS:
if (olen == CILEN_ADDRS) {
p += 2;
GETLONG(cilong, p);
printer(arg, "addrs %I", htonl(cilong));
GETLONG(cilong, p);
printer(arg, " %I", htonl(cilong));
}
break;
case CI_COMPRESSTYPE:
if (olen >= CILEN_COMPRESS) {
p += 2;
GETSHORT(cishort, p);
printer(arg, "compress ");
switch (cishort) {
case IPCP_VJ_COMP:
printer(arg, "VJ");
break;
case IPCP_VJ_COMP_OLD:
printer(arg, "old-VJ");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_ADDR:
if (olen == CILEN_ADDR) {
p += 2;
GETLONG(cilong, p);
printer(arg, "addr %I", htonl(cilong));
}
break;
case CI_MS_DNS1:
case CI_MS_DNS2:
p += 2;
GETLONG(cilong, p);
printer(arg, "ms-dns %I", htonl(cilong));
break;
case CI_MS_WINS1:
case CI_MS_WINS2:
p += 2;
GETLONG(cilong, p);
printer(arg, "ms-wins %I", htonl(cilong));
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(p, len, printer, arg);
p += len;
len = 0;
}
break;
}
/* print the rest of the bytes in the packet */
for (; len > 0; --len) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
return p - pstart;
}
/*
* ip_active_pkt - see if this IP packet is worth bringing the link up for.
* We don't bring the link up for IP fragments or for TCP FIN packets
* with no data.
*/
#define IP_HDRLEN 20 /* bytes */
#define IP_OFFMASK 0x1fff
#define IPPROTO_TCP 6
#define TCP_HDRLEN 20
#define TH_FIN 0x01
/*
* We use these macros because the IP header may be at an odd address,
* and some compilers might use word loads to get th_off or ip_hl.
*/
#define net_short(x) (((x)[0] << 8) + (x)[1])
#define get_iphl(x) (((unsigned char *)(x))[0] & 0xF)
#define get_ipoff(x) net_short((unsigned char *)(x) + 6)
#define get_ipproto(x) (((unsigned char *)(x))[9])
#define get_tcpoff(x) (((unsigned char *)(x))[12] >> 4)
#define get_tcpflags(x) (((unsigned char *)(x))[13])
static int
ip_active_pkt(pkt, len)
u_char *pkt;
int len;
{
u_char *tcp;
int hlen;
len -= PPP_HDRLEN;
pkt += PPP_HDRLEN;
if (len < IP_HDRLEN)
return 0;
if ((get_ipoff(pkt) & IP_OFFMASK) != 0)
return 0;
if (get_ipproto(pkt) != IPPROTO_TCP)
return 1;
hlen = get_iphl(pkt) * 4;
if (len < hlen + TCP_HDRLEN)
return 0;
tcp = pkt + hlen;
if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
return 0;
return 1;
}
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