562 lines
12 KiB
C
562 lines
12 KiB
C
/*
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* upap.c - User/Password Authentication Protocol.
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*
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* Copyright (c) 1989 Carnegie Mellon University.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by Carnegie Mellon University. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#ifndef lint
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static char rcsid[] = "$Id: upap.c,v 1.2 1994/09/25 02:32:16 wollman Exp $";
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#endif
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/*
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* TODO:
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*/
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/time.h>
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#include <syslog.h>
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#include "ppp.h"
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#include "pppd.h"
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#include "upap.h"
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upap_state upap[NPPP]; /* UPAP state; one for each unit */
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static void upap_timeout __ARGS((caddr_t));
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static void upap_rauthreq __ARGS((upap_state *, u_char *, int, int));
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static void upap_rauthack __ARGS((upap_state *, u_char *, int, int));
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static void upap_rauthnak __ARGS((upap_state *, u_char *, int, int));
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static void upap_sauthreq __ARGS((upap_state *));
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static void upap_sresp __ARGS((upap_state *, int, int, char *, int));
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/*
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* upap_init - Initialize a UPAP unit.
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*/
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void
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upap_init(unit)
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int unit;
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{
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upap_state *u = &upap[unit];
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u->us_unit = unit;
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u->us_user = NULL;
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u->us_userlen = 0;
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u->us_passwd = NULL;
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u->us_passwdlen = 0;
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u->us_clientstate = UPAPCS_INITIAL;
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u->us_serverstate = UPAPSS_INITIAL;
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u->us_id = 0;
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u->us_timeouttime = UPAP_DEFTIMEOUT;
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u->us_maxtransmits = 10;
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}
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/*
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* upap_authwithpeer - Authenticate us with our peer (start client).
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*
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* Set new state and send authenticate's.
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*/
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void
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upap_authwithpeer(unit, user, password)
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int unit;
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char *user, *password;
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{
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upap_state *u = &upap[unit];
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/* Save the username and password we're given */
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u->us_user = user;
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u->us_userlen = strlen(user);
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u->us_passwd = password;
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u->us_passwdlen = strlen(password);
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u->us_transmits = 0;
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/* Lower layer up yet? */
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if (u->us_clientstate == UPAPCS_INITIAL ||
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u->us_clientstate == UPAPCS_PENDING) {
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u->us_clientstate = UPAPCS_PENDING;
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return;
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}
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upap_sauthreq(u); /* Start protocol */
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}
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/*
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* upap_authpeer - Authenticate our peer (start server).
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*
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* Set new state.
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*/
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void
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upap_authpeer(unit)
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int unit;
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{
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upap_state *u = &upap[unit];
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/* Lower layer up yet? */
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if (u->us_serverstate == UPAPSS_INITIAL ||
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u->us_serverstate == UPAPSS_PENDING) {
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u->us_serverstate = UPAPSS_PENDING;
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return;
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}
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u->us_serverstate = UPAPSS_LISTEN;
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}
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/*
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* upap_timeout - Timeout expired.
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*/
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static void
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upap_timeout(arg)
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caddr_t arg;
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{
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upap_state *u = (upap_state *) arg;
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if (u->us_clientstate != UPAPCS_AUTHREQ)
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return;
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if (u->us_transmits >= u->us_maxtransmits) {
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/* give up in disgust */
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syslog(LOG_ERR, "No response to PAP authenticate-requests");
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u->us_clientstate = UPAPCS_BADAUTH;
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auth_withpeer_fail(u->us_unit, UPAP);
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return;
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}
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upap_sauthreq(u); /* Send Authenticate-Request */
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}
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/*
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* upap_lowerup - The lower layer is up.
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*
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* Start authenticating if pending.
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*/
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void
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upap_lowerup(unit)
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int unit;
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{
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upap_state *u = &upap[unit];
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if (u->us_clientstate == UPAPCS_INITIAL)
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u->us_clientstate = UPAPCS_CLOSED;
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else if (u->us_clientstate == UPAPCS_PENDING) {
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upap_sauthreq(u); /* send an auth-request */
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}
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if (u->us_serverstate == UPAPSS_INITIAL)
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u->us_serverstate = UPAPSS_CLOSED;
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else if (u->us_serverstate == UPAPSS_PENDING)
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u->us_serverstate = UPAPSS_LISTEN;
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}
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/*
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* upap_lowerdown - The lower layer is down.
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*
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* Cancel all timeouts.
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*/
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void
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upap_lowerdown(unit)
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int unit;
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{
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upap_state *u = &upap[unit];
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if (u->us_clientstate == UPAPCS_AUTHREQ) /* Timeout pending? */
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UNTIMEOUT(upap_timeout, (caddr_t) u); /* Cancel timeout */
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u->us_clientstate = UPAPCS_INITIAL;
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u->us_serverstate = UPAPSS_INITIAL;
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}
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/*
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* upap_protrej - Peer doesn't speak this protocol.
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*
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* This shouldn't happen. In any case, pretend lower layer went down.
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*/
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void
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upap_protrej(unit)
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int unit;
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{
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upap_state *u = &upap[unit];
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if (u->us_clientstate == UPAPCS_AUTHREQ) {
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syslog(LOG_ERR, "PAP authentication failed due to protocol-reject");
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auth_withpeer_fail(unit, UPAP);
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}
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if (u->us_serverstate == UPAPSS_LISTEN) {
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syslog(LOG_ERR, "PAP authentication of peer failed (protocol-reject)");
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auth_peer_fail(unit, UPAP);
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}
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upap_lowerdown(unit);
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}
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/*
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* upap_input - Input UPAP packet.
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*/
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void
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upap_input(unit, inpacket, l)
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int unit;
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u_char *inpacket;
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int l;
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{
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upap_state *u = &upap[unit];
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u_char *inp;
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u_char code, id;
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int len;
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/*
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* Parse header (code, id and length).
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* If packet too short, drop it.
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*/
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inp = inpacket;
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if (l < UPAP_HEADERLEN) {
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UPAPDEBUG((LOG_INFO, "upap_input: rcvd short header."));
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return;
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}
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GETCHAR(code, inp);
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GETCHAR(id, inp);
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GETSHORT(len, inp);
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if (len < UPAP_HEADERLEN) {
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UPAPDEBUG((LOG_INFO, "upap_input: rcvd illegal length."));
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return;
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}
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if (len > l) {
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UPAPDEBUG((LOG_INFO, "upap_input: rcvd short packet."));
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return;
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}
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len -= UPAP_HEADERLEN;
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/*
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* Action depends on code.
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*/
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switch (code) {
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case UPAP_AUTHREQ:
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upap_rauthreq(u, inp, id, len);
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break;
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case UPAP_AUTHACK:
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upap_rauthack(u, inp, id, len);
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break;
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case UPAP_AUTHNAK:
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upap_rauthnak(u, inp, id, len);
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break;
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default: /* XXX Need code reject */
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break;
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}
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}
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/*
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* upap_rauth - Receive Authenticate.
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*/
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static void
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upap_rauthreq(u, inp, id, len)
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upap_state *u;
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u_char *inp;
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int id;
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int len;
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{
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u_char ruserlen, rpasswdlen;
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char *ruser, *rpasswd;
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int retcode;
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char *msg;
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int msglen;
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UPAPDEBUG((LOG_INFO, "upap_rauth: Rcvd id %d.", id));
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if (u->us_serverstate < UPAPSS_LISTEN)
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return;
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/*
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* If we receive a duplicate authenticate-request, we are
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* supposed to return the same status as for the first request.
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*/
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if (u->us_serverstate == UPAPSS_OPEN) {
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upap_sresp(u, UPAP_AUTHACK, id, "", 0); /* return auth-ack */
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return;
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}
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if (u->us_serverstate == UPAPSS_BADAUTH) {
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upap_sresp(u, UPAP_AUTHNAK, id, "", 0); /* return auth-nak */
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return;
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}
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/*
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* Parse user/passwd.
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*/
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if (len < sizeof (u_char)) {
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UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
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return;
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}
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GETCHAR(ruserlen, inp);
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len -= sizeof (u_char) + ruserlen + sizeof (u_char);
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if (len < 0) {
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UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
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return;
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}
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ruser = (char *) inp;
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INCPTR(ruserlen, inp);
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GETCHAR(rpasswdlen, inp);
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if (len < rpasswdlen) {
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UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
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return;
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}
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rpasswd = (char *) inp;
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/*
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* Check the username and password given.
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*/
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retcode = check_passwd(u->us_unit, ruser, ruserlen, rpasswd,
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rpasswdlen, &msg, &msglen);
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upap_sresp(u, retcode, id, msg, msglen);
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if (retcode == UPAP_AUTHACK) {
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u->us_serverstate = UPAPSS_OPEN;
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auth_peer_success(u->us_unit, UPAP);
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} else {
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u->us_serverstate = UPAPSS_BADAUTH;
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auth_peer_fail(u->us_unit, UPAP);
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}
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}
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/*
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* upap_rauthack - Receive Authenticate-Ack.
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*/
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static void
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upap_rauthack(u, inp, id, len)
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upap_state *u;
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u_char *inp;
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int id;
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int len;
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{
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u_char msglen;
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char *msg;
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UPAPDEBUG((LOG_INFO, "upap_rauthack: Rcvd id %d.", id));
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if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
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return;
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/*
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* Parse message.
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*/
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if (len < sizeof (u_char)) {
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UPAPDEBUG((LOG_INFO, "upap_rauthack: rcvd short packet."));
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return;
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}
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GETCHAR(msglen, inp);
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len -= sizeof (u_char);
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if (len < msglen) {
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UPAPDEBUG((LOG_INFO, "upap_rauthack: rcvd short packet."));
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return;
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}
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msg = (char *) inp;
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PRINTMSG(msg, msglen);
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u->us_clientstate = UPAPCS_OPEN;
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auth_withpeer_success(u->us_unit, UPAP);
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}
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/*
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* upap_rauthnak - Receive Authenticate-Nakk.
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*/
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static void
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upap_rauthnak(u, inp, id, len)
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upap_state *u;
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u_char *inp;
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int id;
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int len;
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{
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u_char msglen;
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char *msg;
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UPAPDEBUG((LOG_INFO, "upap_rauthnak: Rcvd id %d.", id));
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if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
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return;
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/*
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* Parse message.
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*/
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if (len < sizeof (u_char)) {
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UPAPDEBUG((LOG_INFO, "upap_rauthnak: rcvd short packet."));
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return;
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}
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GETCHAR(msglen, inp);
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len -= sizeof (u_char);
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if (len < msglen) {
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UPAPDEBUG((LOG_INFO, "upap_rauthnak: rcvd short packet."));
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return;
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}
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msg = (char *) inp;
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PRINTMSG(msg, msglen);
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u->us_clientstate = UPAPCS_BADAUTH;
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syslog(LOG_ERR, "PAP authentication failed");
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auth_withpeer_fail(u->us_unit, UPAP);
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}
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/*
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* upap_sauthreq - Send an Authenticate-Request.
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*/
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static void
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upap_sauthreq(u)
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upap_state *u;
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{
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u_char *outp;
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int outlen;
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outlen = UPAP_HEADERLEN + 2 * sizeof (u_char) +
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u->us_userlen + u->us_passwdlen;
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outp = outpacket_buf;
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MAKEHEADER(outp, UPAP);
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PUTCHAR(UPAP_AUTHREQ, outp);
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PUTCHAR(++u->us_id, outp);
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PUTSHORT(outlen, outp);
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PUTCHAR(u->us_userlen, outp);
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BCOPY(u->us_user, outp, u->us_userlen);
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INCPTR(u->us_userlen, outp);
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PUTCHAR(u->us_passwdlen, outp);
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BCOPY(u->us_passwd, outp, u->us_passwdlen);
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output(u->us_unit, outpacket_buf, outlen + DLLHEADERLEN);
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UPAPDEBUG((LOG_INFO, "upap_sauth: Sent id %d.", u->us_id));
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TIMEOUT(upap_timeout, (caddr_t) u, u->us_timeouttime);
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++u->us_transmits;
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u->us_clientstate = UPAPCS_AUTHREQ;
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}
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/*
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* upap_sresp - Send a response (ack or nak).
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*/
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static void
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upap_sresp(u, code, id, msg, msglen)
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upap_state *u;
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u_char code, id;
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char *msg;
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int msglen;
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{
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u_char *outp;
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int outlen;
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outlen = UPAP_HEADERLEN + sizeof (u_char) + msglen;
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outp = outpacket_buf;
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MAKEHEADER(outp, UPAP);
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PUTCHAR(code, outp);
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PUTCHAR(id, outp);
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PUTSHORT(outlen, outp);
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PUTCHAR(msglen, outp);
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BCOPY(msg, outp, msglen);
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output(u->us_unit, outpacket_buf, outlen + DLLHEADERLEN);
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UPAPDEBUG((LOG_INFO, "upap_sresp: Sent code %d, id %d.", code, id));
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}
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/*
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* upap_printpkt - print the contents of a PAP packet.
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*/
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char *upap_codenames[] = {
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"AuthReq", "AuthAck", "AuthNak"
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};
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int
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upap_printpkt(p, plen, printer, arg)
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u_char *p;
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int plen;
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void (*printer) __ARGS((void *, char *, ...));
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void *arg;
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{
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int code, id, len;
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int mlen, ulen, wlen;
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char *user, *pwd, *msg;
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u_char *pstart;
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if (plen < UPAP_HEADERLEN)
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return 0;
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pstart = p;
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GETCHAR(code, p);
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GETCHAR(id, p);
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GETSHORT(len, p);
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if (len < UPAP_HEADERLEN || len > plen)
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return 0;
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if (code >= 1 && code <= sizeof(upap_codenames) / sizeof(char *))
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printer(arg, " %s", upap_codenames[code-1]);
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else
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printer(arg, " code=0x%x", code);
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printer(arg, " id=0x%x", id);
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len -= UPAP_HEADERLEN;
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switch (code) {
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case UPAP_AUTHREQ:
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if (len < 1)
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break;
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ulen = p[0];
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if (len < ulen + 2)
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break;
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wlen = p[ulen + 1];
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if (len < ulen + wlen + 2)
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break;
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user = (char *) (p + 1);
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pwd = (char *) (p + ulen + 2);
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p += ulen + wlen + 2;
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len -= ulen + wlen + 2;
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printer(arg, " user=");
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print_string(user, ulen, printer, arg);
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printer(arg, " password=");
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print_string(pwd, wlen, printer, arg);
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break;
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case UPAP_AUTHACK:
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case UPAP_AUTHNAK:
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if (len < 1)
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break;
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mlen = p[0];
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if (len < mlen + 1)
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break;
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msg = (char *) (p + 1);
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p += mlen + 1;
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len -= mlen + 1;
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printer(arg, "msg=");
|
|
print_string(msg, mlen, printer, arg);
|
|
break;
|
|
}
|
|
|
|
/* print the rest of the bytes in the packet */
|
|
for (; len > 0; --len) {
|
|
GETCHAR(code, p);
|
|
printer(arg, " %.2x", code);
|
|
}
|
|
|
|
return p - pstart;
|
|
}
|