radius.c

linux下的ppp协议簇开源代码； 可以进行linux内核级的pppoe拨号

/***********************************************************************
*
* radius.c
*
* RADIUS plugin for pppd.  Performs PAP, CHAP, MS-CHAP, MS-CHAPv2
* authentication using RADIUS.
*
* Copyright (C) 2002 Roaring Penguin Software Inc.
*
* Based on a patch for ipppd, which is:
*    Copyright (C) 1996, Matjaz Godec <[e-mail]>
*    Copyright (C) 1996, Lars Fenneberg <[e-mail]>
*    Copyright (C) 1997, Miguel A.L. Paraz <[e-mail]>
*
* Uses radiusclient library, which is:
*    Copyright (C) 1995,1996,1997,1998 Lars Fenneberg <[e-mail]>
*    Copyright (C) 2002 Roaring Penguin Software Inc.
*
* MPPE support is by Ralf Hofmann, <[e-mail]>, with
* modification from Frank Cusack, <[e-mail]>.
*
* This plugin may be distributed according to the terms of the GNU
* General Public License, version 2 or (at your option) any later version.
*
***********************************************************************/
static char const RCSID[] =
"$Id: radius.c,v 1.28 2004/11/14 10:27:57 paulus Exp $";

#include "pppd.h"
#include "chap-new.h"
#ifdef CHAPMS
#include "chap_ms.h"
#ifdef MPPE
#include "md5.h"
#endif
#endif
#include "radiusclient.h"
#include "fsm.h"
#include "ipcp.h"
#include <syslog.h>
#include <sys/types.h>
#include <sys/time.h>
#include <string.h>
#include <netinet/in.h>
#include <stdlib.h>

#define BUF_LEN 1024

#define MD5_HASH_SIZE	16

static char *config_file = NULL;
static int add_avp(char **);
static struct avpopt {
    char *vpstr;
    struct avpopt *next;
} *avpopt = NULL;
static bool portnummap = 0;

static option_t Options[] = {
    { "radius-config-file", o_string, &config_file },
    { "avpair", o_special, add_avp },
    { "map-to-ttyname", o_bool, &portnummap,
	"Set Radius NAS-Port attribute value via libradiusclient library", OPT_PRIO | 1 },
    { "map-to-ifname", o_bool, &portnummap,
	"Set Radius NAS-Port attribute to number as in interface name (Default)", OPT_PRIOSUB | 0 },
    { NULL }
};

static int radius_secret_check(void);
static int radius_pap_auth(char *user,
			   char *passwd,
			   char **msgp,
			   struct wordlist **paddrs,
			   struct wordlist **popts);
static int radius_chap_verify(char *user, char *ourname, int id,
			      struct chap_digest_type *digest,
			      unsigned char *challenge,
			      unsigned char *response,
			      char *message, int message_space);

static void radius_ip_up(void *opaque, int arg);
static void radius_ip_down(void *opaque, int arg);
static void make_username_realm(char *user);
static int radius_setparams(VALUE_PAIR *vp, char *msg, REQUEST_INFO *req_info,
			    struct chap_digest_type *digest,
			    unsigned char *challenge,
			    char *message, int message_space);
static void radius_choose_ip(u_int32_t *addrp);
static int radius_init(char *msg);
static int get_client_port(char *ifname);
static int radius_allowed_address(u_int32_t addr);
static void radius_acct_interim(void *);
#ifdef MPPE
static int radius_setmppekeys(VALUE_PAIR *vp, REQUEST_INFO *req_info,
			      unsigned char *);
static int radius_setmppekeys2(VALUE_PAIR *vp, REQUEST_INFO *req_info);
#endif

#ifndef MAXSESSIONID
#define MAXSESSIONID 32
#endif

#ifndef MAXCLASSLEN
#define MAXCLASSLEN 500
#endif

struct radius_state {
    int accounting_started;
    int initialized;
    int client_port;
    int choose_ip;
    int any_ip_addr_ok;
    int done_chap_once;
    u_int32_t ip_addr;
    char user[MAXNAMELEN];
    char config_file[MAXPATHLEN];
    char session_id[MAXSESSIONID + 1];
    time_t start_time;
    int acct_interim_interval;
    SERVER *authserver;		/* Authentication server to use */
    SERVER *acctserver;		/* Accounting server to use */
    int class_len;
    char class[MAXCLASSLEN];
    VALUE_PAIR *avp;	/* Additional (user supplied) vp's to send to server */
};

void (*radius_attributes_hook)(VALUE_PAIR *) = NULL;

/* The pre_auth_hook MAY set authserver and acctserver if it wants.
   In that case, they override the values in the radiusclient.conf file */
void (*radius_pre_auth_hook)(char const *user,
			     SERVER **authserver,
			     SERVER **acctserver) = NULL;

static struct radius_state rstate;

char pppd_version[] = VERSION;

/**********************************************************************
* %FUNCTION: plugin_init
* %ARGUMENTS:
*  None
* %RETURNS:
*  Nothing
* %DESCRIPTION:
*  Initializes RADIUS plugin.
***********************************************************************/
void
plugin_init(void)
{
    pap_check_hook = radius_secret_check;
    pap_auth_hook = radius_pap_auth;

    chap_check_hook = radius_secret_check;
    chap_verify_hook = radius_chap_verify;

    ip_choose_hook = radius_choose_ip;
    allowed_address_hook = radius_allowed_address;

    add_notifier(&ip_up_notifier, radius_ip_up, NULL);
    add_notifier(&ip_down_notifier, radius_ip_down, NULL);

    memset(&rstate, 0, sizeof(rstate));

    strlcpy(rstate.config_file, "/etc/radiusclient/radiusclient.conf",
	    sizeof(rstate.config_file));

    add_options(Options);

    info("RADIUS plugin initialized.");
}

/**********************************************************************
* %FUNCTION: add_avp
* %ARGUMENTS:
*  argv -- the <attribute=value> pair to add
* %RETURNS:
*  1
* %DESCRIPTION:
*  Adds an av pair to be passed on to the RADIUS server on each request.
***********************************************************************/
static int
add_avp(char **argv)
{
    struct avpopt *p = malloc(sizeof(struct avpopt));

    /* Append to a list of vp's for later parsing */
    p->vpstr = strdup(*argv);
    p->next = avpopt;
    avpopt = p;

    return 1;
}

/**********************************************************************
* %FUNCTION: radius_secret_check
* %ARGUMENTS:
*  None
* %RETURNS:
*  1 -- we are ALWAYS willing to supply a secret. :-)
* %DESCRIPTION:
* Tells pppd that we will try to authenticate the peer, and not to
* worry about looking in /etc/ppp/*-secrets
***********************************************************************/
static int
radius_secret_check(void)
{
    return 1;
}

/**********************************************************************
* %FUNCTION: radius_choose_ip
* %ARGUMENTS:
*  addrp -- where to store the IP address
* %RETURNS:
*  Nothing
* %DESCRIPTION:
*  If RADIUS server has specified an IP address, it is stored in *addrp.
***********************************************************************/
static void
radius_choose_ip(u_int32_t *addrp)
{
    if (rstate.choose_ip) {
	*addrp = rstate.ip_addr;
    }
}

/**********************************************************************
* %FUNCTION: radius_pap_auth
* %ARGUMENTS:
*  user -- user-name of peer
*  passwd -- password supplied by peer
*  msgp -- Message which will be sent in PAP response
*  paddrs -- set to a list of possible peer IP addresses
*  popts -- set to a list of additional pppd options
* %RETURNS:
*  1 if we can authenticate, -1 if we cannot.
* %DESCRIPTION:
* Performs PAP authentication using RADIUS
***********************************************************************/
static int
radius_pap_auth(char *user,
		char *passwd,
		char **msgp,
		struct wordlist **paddrs,
		struct wordlist **popts)
{
    VALUE_PAIR *send, *received;
    UINT4 av_type;
    int result;
    static char radius_msg[BUF_LEN];

    radius_msg[0] = 0;
    *msgp = radius_msg;

    if (radius_init(radius_msg) < 0) {
	return 0;
    }

    /* Put user with potentially realm added in rstate.user */
    make_username_realm(user);

    if (radius_pre_auth_hook) {
	radius_pre_auth_hook(rstate.user,
			     &rstate.authserver,
			     &rstate.acctserver);
    }

    send = NULL;
    received = NULL;

    /* Hack... the "port" is the ppp interface number.  Should really be
       the tty */
    rstate.client_port = get_client_port(portnummap ? devnam : ifname);

    av_type = PW_FRAMED;
    rc_avpair_add(&send, PW_SERVICE_TYPE, &av_type, 0, VENDOR_NONE);

    av_type = PW_PPP;
    rc_avpair_add(&send, PW_FRAMED_PROTOCOL, &av_type, 0, VENDOR_NONE);

    rc_avpair_add(&send, PW_USER_NAME, rstate.user , 0, VENDOR_NONE);
    rc_avpair_add(&send, PW_USER_PASSWORD, passwd, 0, VENDOR_NONE);
    if (*remote_number) {
	rc_avpair_add(&send, PW_CALLING_STATION_ID, remote_number, 0,
		       VENDOR_NONE);
    } else if (ipparam)
	rc_avpair_add(&send, PW_CALLING_STATION_ID, ipparam, 0, VENDOR_NONE);

    /* Add user specified vp's */
    if (rstate.avp)
	rc_avpair_insert(&send, NULL, rc_avpair_copy(rstate.avp));

    if (rstate.authserver) {
	result = rc_auth_using_server(rstate.authserver,
				      rstate.client_port, send,
				      &received, radius_msg, NULL);
    } else {
	result = rc_auth(rstate.client_port, send, &received, radius_msg, NULL);
    }

    if (result == OK_RC) {
	if (radius_setparams(received, radius_msg, NULL, NULL, NULL, NULL, 0) < 0) {
	    result = ERROR_RC;
	}
    }

    /* free value pairs */
    rc_avpair_free(received);
    rc_avpair_free(send);

    return (result == OK_RC) ? 1 : 0;
}

/**********************************************************************
* %FUNCTION: radius_chap_verify
* %ARGUMENTS:
*  user -- name of the peer
*  ourname -- name for this machine
*  id -- the ID byte in the challenge
*  digest -- points to the structure representing the digest type
*  challenge -- the challenge string we sent (length in first byte)
*  response -- the response (hash) the peer sent back (length in 1st byte)
*  message -- space for a message to be returned to the peer
*  message_space -- number of bytes available at *message.
* %RETURNS:
*  1 if the response is good, 0 if it is bad
* %DESCRIPTION:
* Performs CHAP, MS-CHAP and MS-CHAPv2 authentication using RADIUS.
***********************************************************************/
static int
radius_chap_verify(char *user, char *ourname, int id,
		   struct chap_digest_type *digest,
		   unsigned char *challenge, unsigned char *response,
		   char *message, int message_space)
{
    VALUE_PAIR *send, *received;
    UINT4 av_type;
    static char radius_msg[BUF_LEN];
    int result;
    int challenge_len, response_len;
    u_char cpassword[MAX_RESPONSE_LEN + 1];
#ifdef MPPE
    /* Need the RADIUS secret and Request Authenticator to decode MPPE */
    REQUEST_INFO request_info, *req_info = &request_info;
#else
    REQUEST_INFO *req_info = NULL;
#endif

    challenge_len = *challenge++;
    response_len = *response++;

    radius_msg[0] = 0;

    if (radius_init(radius_msg) < 0) {
	error("%s", radius_msg);
	return 0;
    }

    /* return error for types we can't handle */
    if ((digest->code != CHAP_MD5)
#ifdef CHAPMS
	&& (digest->code != CHAP_MICROSOFT)
	&& (digest->code != CHAP_MICROSOFT_V2)
#endif
	) {
	error("RADIUS: Challenge type %u unsupported", digest->code);
	return 0;
    }

    /* Put user with potentially realm added in rstate.user */
    if (!rstate.done_chap_once) {
	make_username_realm(user);
	rstate.client_port = get_client_port (portnummap ? devnam : ifname);
	if (radius_pre_auth_hook) {
	    radius_pre_auth_hook(rstate.user,
				 &rstate.authserver,
				 &rstate.acctserver);
	}
    }

    send = received = NULL;

    av_type = PW_FRAMED;
    rc_avpair_add (&send, PW_SERVICE_TYPE, &av_type, 0, VENDOR_NONE);

    av_type = PW_PPP;
    rc_avpair_add (&send, PW_FRAMED_PROTOCOL, &av_type, 0, VENDOR_NONE);

    rc_avpair_add (&send, PW_USER_NAME, rstate.user , 0, VENDOR_NONE);

    /*
     * add the challenge and response fields
     */
    switch (digest->code) {
    case CHAP_MD5:
	/* CHAP-Challenge and CHAP-Password */
	if (response_len != MD5_HASH_SIZE)
	    return 0;
	cpassword[0] = id;
	memcpy(&cpassword[1], response, MD5_HASH_SIZE);

	rc_avpair_add(&send, PW_CHAP_CHALLENGE,
		      challenge, challenge_len, VENDOR_NONE);
	rc_avpair_add(&send, PW_CHAP_PASSWORD,
		      cpassword, MD5_HASH_SIZE + 1, VENDOR_NONE);
	break;

#ifdef CHAPMS
    case CHAP_MICROSOFT:
    {
	/* MS-CHAP-Challenge and MS-CHAP-Response */
	MS_ChapResponse *rmd = (MS_ChapResponse *) response;
	u_char *p = cpassword;

	if (response_len != MS_CHAP_RESPONSE_LEN)
	    return 0;
	*p++ = id;
	/* The idiots use a different field order in RADIUS than PPP */
	memcpy(p, rmd->UseNT, sizeof(rmd->UseNT));
	p += sizeof(rmd->UseNT);
	memcpy(p, rmd->LANManResp, sizeof(rmd->LANManResp));
	p += sizeof(rmd->LANManResp);
	memcpy(p, rmd->NTResp, sizeof(rmd->NTResp));

	rc_avpair_add(&send, PW_MS_CHAP_CHALLENGE,
		      challenge, challenge_len, VENDOR_MICROSOFT);
	rc_avpair_add(&send, PW_MS_CHAP_RESPONSE,
		      cpassword, MS_CHAP_RESPONSE_LEN + 1, VENDOR_MICROSOFT);
	break;
    }

    case CHAP_MICROSOFT_V2:
    {
	/* MS-CHAP-Challenge and MS-CHAP2-Response */
	MS_Chap2Response *rmd = (MS_Chap2Response *) response;